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Warm hints: The word in this article is about 2000 and  reading time is about 10 minutes.SummaryIn ten years ago,the average selling price of industrial robots is about 500 thousand;however, the price is now four large family robot 15-20 million,Eft, and other domestic price slightly lower than the eston robot four family, economic type of pure domestic robot (terminal sales price of about 80 thousand. It is estimated that in the future, the average price of industrial robots will be reduced to less than 50 thousand with the localization of the spare parts and other parts.  CoreIndustrial RobotsCategoryRobotKeywordsindustrial robots;cloud service robotContentFuture market prediction about industrial robots in China Catalogs CatalogsI. The Statistics of Industrial robots Sales in recent yearsII.One of the development trends of industrial robots: more flexibleIII.The two development trend of industrial robots: low cost economy OntologyIV.Prediction about Industrial Robot IntroductionBefore we read the artcle,let's see a video about "MIT cheetah robot lands the running jump".In a leap for robotic development, the MIT researchers who built a robotic cheetah have now trained it to see and jump over hurdles as it runs — making this the first four-legged robot to run and jump over obstacles autonomously.  I. The Statistics of Industrial robots Sales in recent yearsWe know that science and technology are constantly growing after see the above video. According to IFE statistics,the global industrial robot sales exceeded $13 billion 200 million (plus integration part, system on the industrial robot market is about $50 billion) in 2016,with the major economies of the global industrial automation,robot using density increase. What’s more, IFR predicted that the world robot sales were 34.7, 37.8, 43.5 and 522 thousand respectively when in 2017-2020 years,and CAGR reached 15.4% in the next 4 years.Prediction of the sales of industrial robots in the global marketAccording to statistics, in 2016, domestic industrial robot sales hit a new high, reaching 87 thousand units, and by December 2017, China's industrial robot output reached 131 thousand units (set), an increase of 51% over the same period, and sales volume is expected to continue to grow this year. According to the prediction of IFR, 2018-2020 years of domestic robot sales were 16, 19.5, 238 thousand, 22% to 3 years in the future CAGR.Prediction of the sales of industrial robots in the global market In 2017, the domestic industrial robot market rapid growth for two reasons, one is the demand of the robot driven by 3C's apple, the other is the general manufacturing robots used in large-scale attempt, many general manufacturing enterprises, such as the winery, an order in more than 100. The difficulty of recruiting workers and the high cost of recruiting workers are becoming more and more common, which makes the demand for robots increase.At present, the domestic robots are mainly used in the general manufacturing industry other than cars and 3C. This year, not only foreign brands, but also domestic industrial robots.Domestic industrial robot sales structure in 2016 and over the yearsAccording to the National Bureau of statistics, China has 50 million manufacturing workers in each industrial robot instead of 2-3 workers, the potential stock market will reach 1800-2500 million units, taking into account a lot of jobs cannot substitute robots, may the actual market is not so big. We discussed with industry experts, five years can be seen in the domestic market sales reached 50-60 million units.Prediction of the sales of industrial robots in the global market AnalysisII.One of the development trends of industrial robots: more flexibleIn order to increase the use of industrial robots, the robot is more flexible. DFKI (German Research Center for artificial intelligence, is Germany's top intelligence research institutions, is currently the world's largest non-profit artificial intelligence research institutions, its shareholders include Google, Intel, Microsoft, BMW, SAP, Airbus, the global top ten enterprises of science and Technology) developed intelligent assembly robot, can through the abstract memory system for assembly, adaptive grasping and intelligent products specifically, is in the head mounted stereoscopic camera, camera mounted near the object in the arm; at the same time, using the left internal antenna reads from the inside of the product size, weight and hot.DFKI Grasping and assembling robotInter-generational evolution of industrial robots: robots are undergoing a shift from "machine" to human. We can divide the robot into three generations, the first generation of traditional industrial robots, which have not changed significantly for nearly 50 years. The second generation is a "feeling" robot. They have a certain sense of perception in the outside world, with visual, tactile and auditory functions. Such as a cooperative robot, a arc welding robot that automatically tracks the weld according to the laser feedback. The third generation planning based on artificial intelligence technology, robot control, according to their perception of information, independent thinking, recognition and reasoning, and make judgments and decisions, without human intervention automatically, become the main production system, can even replace machine and other machine tools, such as cloud service robot.The robot is undergoing a change from "machine" to "man"The second generation of robot representatives: UR cooperative robot. At present, cooperative robots occupy a part of the market with their safety, low cost, easy to use and low cost of transformation, especially for small and medium-sized enterprises which are mainly small batch and customized. However, in the long run, human-computer cooperation is the direction, and the potential of the cooperative robot market is great.UR5 apply in Volkswagen automobile production lineBecause of the great prospect of the cooperative robot, the robot enterprises both at home and abroad have the product development and sale, and have obtained the better market response. Although the domestic collaboration robot started late, but in the past two years, many products appeared in the development. In China, especially for the electronics industry, the domestic cooperative robot has a promising commercial prospect.Typical enterprise and product of cooperative robotThe third generation of robot - cloud service robot. Cloud service robots, integrating the latest information technology, will produce more dramatic changes in the impact of artificial intelligence and industrial robots.In 2015, the domestic industrial robot AIFUTE leading enterprises began the layout of the next generation of robot technology, and the Silicon Valley in the United States set up R & D center. A preliminary cloud robot platform product will be formed in 2018.The concept of cloud evert robotIII.The two development trend of industrial robots: low cost economy OntologyThe medium and small businesses can receive the longest payback period of two years, preferably one year, so the industrial robots should be popularized in China. In the long run, the price should be controlled at least 100 thousand. ConclusionIV.Prediction about Industrial RobotIndustrial robot in 10 years ago, the average selling price of about 500 thousand, the price is now four large family robot 15-20 million, Eft, and other domestic price slightly lower than the eston robot four family, economic type of pure domestic robot (terminal sales price of about 80 thousand. It is estimated that in the future, the average price of industrial robots will be reduced to less than 50 thousand with the localization of the spare parts and other parts.  Book Recommendation House of Robots: Robot Revolution Hardcover – January 16, 2017After a few early glitches in their relationship, Sammy and his "bro-bot" E are now fast friends. In fact, E is such a valued member of the family that the other electronic occupants of the House of Robots are feeling sorely unappreciated. And when Sammy's inventor mom becomes distracted by a top-secret project, the robots soon begin to fall into disrepair.Cue a robot revolt, with the droids wreaking harmless havoc in the house! Armed with pranks like glue in the shampoo bottles and flying toast missiles, the robots demand to be cared for. It's up to Sammy and his disabled sister Maddie to keep the peace until his mom reveals her secret project...and why it was worth the wait.--James Patterson  (Author),‎ Juliana Neufeld (Illustrator),‎ Chris Grabenstein (Contributor) Rise of the Robots: Technology and the Threat of a Jobless Future Paperback – July 12, 2016What are the jobs of the future? How many will there be? And who will have them? As technology continues to accelerate and machines begin taking care of themselves, fewer people will be necessary. Artificial intelligence is already well on its way to making "good jobs" obsolete: many paralegals, journalists, office workers, and even computer programmers are poised to be replaced by robots and smart software. As progress continues, blue and white collar jobs alike will evaporate, squeezing working- and middle-class families ever further. At the same time, households are under assault from exploding costs, especially from the two major industries-education and health care-that, so far, have not been transformed by information technology. The result could well be massive unemployment and inequality as well as the implosion of the consumer economy itself.The past solutions to technological disruption, especially more training and education, aren't going to work. We must decide, now, whether the future will see boad-based prosperity or catastrophic levels of inequality and economic insecurity. Rise of the Robots is essential reading to understand what accelerating technology means for our economic prospects-not to mention those of our children-as well as for society as a whole.--Martin Ford  (Author)Robot-Proof: Higher Education in the Age of Artificial Intelligence (MIT Press) Hardcover – August 25, 2017How to educate the next generation of college students to invent, to create, and to discover -- filling needs that even the most sophisticated robot cannot.Driverless cars are hitting the road, powered by artificial intelligence. Robots can climb stairs, open doors, win Jeopardy, analyze stocks, work in factories, find parking spaces, advise oncologists. In the past, automation was considered a threat to low-skilled labor. Now, many high-skilled functions, including interpreting medical images, doing legal research, and analyzing data, are within the skill sets of machines. How can higher education prepare students for their professional lives when professions themselves are disappearing? In Robot-Proof, Northeastern University president Joseph Aoun proposes a way to educate the next generation of college students to invent, to create, and to discover -- to fill needs in society that even the most sophisticated artificial intelligence agent cannot.A "robot-proof" education, Aoun argues, is not concerned solely with topping up students' minds with high-octane facts. Rather, it calibrates them with a creative mindset and the mental elasticity to invent, discover, or create something valuable to society -- a scientific proof, a hip-hop recording, a web comic, a cure for cancer. Aoun lays out the framework for a new discipline, humanics, which builds on our innate strengths and prepares students to compete in a labor market in which smart machines work alongside human professionals. The new literacies of Aoun's humanics are data literacy, technological literacy, and human literacy. Students will need data literacy to manage the flow of big data, and technological literacy to know how their machines work, but human literacy -- the humanities, communication, and design -- to function as a human being. Life-long learning opportunities will support their ability to adapt to change.The only certainty about the future is change. Higher education based on the new literacies of humanics can equip students for living and working through change.--Joseph E. Aoun (Author)  Relevant information about "The Future Market of Industrial Robots in China will Be Far Beyond Imagination"About the article "The Future Market of Industrial Robots in China will Be Far Beyond Imagination", If you have better ideas, don't hesitate to  write your thoughts in the following comment area. You also can find more articles about electronic semiconductor through Google search engine, or refer to the following related articles. Living Insect-Machine Hybrid Robot--Swarming Search and RescueMake Robots Walk NaturallyEngineers from MIT Developed A Tiny, Affordable Robotic Device That Can Detect Water LeakThree Fingers Robotic Hand with Specialized Sensors can Estimate Size and Shape of ObjectsA New, Electronic Skin Microsystem Enables People Tracks Their Heart Rate And Other Health Index

Warm hints: The word in this article is about 2500 and  reading time is about 12 minutes. Summary In the power system, in addition to the traditional harmonic sources, such as electric arc furnace and frequency converter, the nonlinear loads such as new energy access and charging pile may produce a lot of harmonics. In order to prevent harmonic from further affecting the power grid, accurate monitoring and timely treatment of harmonic level in power grid is a necessary step. The correct measurement of harmonic content in power grid is the basis of monitoring and governance. This paper mainly introduces some basic  knowledge about capacitor voltage transformer including the capacitor voltage transformer symbol; testing; working principle; capacitive voltage transformer VS inductive voltage transformer and etc. Article core capacitor voltage transformer Abbreviation CVT English name capacitor voltage transformer Category Power Subject Power engineer compose Capacitive voltage divider and medium voltage transformer Field Energy         Catalogs I. What is Capacitor Voltage Transformer( CVT)3.1 Insulation Resistance Measurement1.1 The Composition of CVT3.2 Capacitance Measurement1.2 CTV Judgment of Common Anomalies3.3 Pressure Swing Ratio Test1.3 CVT Equivalent Circuit Model3.4 Polar MeasurementII.Terminal Sign of Capacitive Voltage TransformerIV.Working Principle of Capacitive Voltage Transformer （CVT)III.Capacitor Voltage Transformer TestingV.Capacitive Voltage Transformer VS Inductive Voltage TransformerⅥ. FAQ  Introduction I. What is Capacitor Voltage Transformer( CVT) 1.1 The composition of CVT 一、The capacitive voltage transformer is mainly composed of a capacitor voltage divider and a medium voltage transformer. The capacitor divider is made up of porcelain bushing and series capacitors installed in it. The porcelain bushing is filled with insulating oil that keeps 0.1MPa positive pressure, and steel bellows are used to balance different environments to maintain oil pressure. The capacitor divider can be used as a coupling capacitor to connect the carrier device. The medium voltage transformer is composed of a transformer, a compensating reactor, a lightning arrester and a damping device installed in a sealed tank, and the space on the top of the tank is filled with nitrogen. The primary windings are divided into main windings and fine tuning windings, and a low loss reactor is connected in series between one side and one winding. Due to the capacitance and the inherent nonlinear impedance of the capacitor voltage transformer sometimes cause Ferroresonance in capacitor voltage transformer, thus suppressing resonant damping device, damping device is composed of a resistor and reactor, connected across the two windings, normally the damping device has very high impedance, when iron magnetic resonance caused by overvoltage in medium voltage transformer affected before the reactor is saturated only resistive load, the oscillation energy will soon be reduced. 1.2 CTV Judgment of common anomalies (1)The secondary voltage fluctuation. The two connection is loose, the distributor is not grounded or the carrier coil is not connected. If the damper is a fast saturable reactor, it may be improper parameter matching. (2)The Secondary voltage is low. Its connection is bad and the electromagnetic unit failure or the capacitor unit C2 is damaged. (3)The secondary voltage is high.The capacitance unit C1 is damaged and the ground end of the partial voltage capacitor is ungrounded. (4)The oil level of the electromagnetic unit is too high. The next capacitance unit is leaking oil or electromagnetic unit into the water. (5)There is a different sound in the transportation. Bolt loosening of reactor or medium pressure rheostat in electromagnetic unit. 1.3 CVT equivalent circuit model Under the condition of steady state, the whole CVT equivalent circuit can be regarded as a linear system, which compensates the stray capacitance of reactor C. The influence of the primary stray capacitance C: of the intermediate transformer at the high frequency can not be ignored. CVT intermediate transformer core can be regarded as linear segments in the magnetization curve, ignoring the core magnetizing inductance, one or two intermediate transformer side leakage resistance reduction to compensation reactor.   II.Terminal sign of capacitive voltage transformer · A single phase transformer with a two - time winding   It represents a single-phase transformer with two times winding. A represents the primary winding terminal of capacitive voltage transformer, and N represents the primary winding grounding terminal of voltage transformer. A represents the two winding terminal terminal of a capacitive voltage transformer, and N represents the first winding grounding terminal of the voltage transformer. · Single phase transformer with two two times windings   It represents a single-phase transformer with two two times windings, A represents the primary winding terminals of capacitive voltage transformers, and N represents the primary winding grounding terminals of voltage transformers. 1A and 2A represent the two winding terminals of the capacitive voltage transformer, and 1n and 2n represent the primary winding grounding terminals of the voltage transformer. · A single phase transformer with two two windings with a tap A single phase transformer with two taps and two winding is represented. A represents the primary winding terminal of capacitive voltage transformer, and N represents the primary winding grounding terminal of voltage transformer. 1A1, 1A2, 2a and 2A2 respectively represent the two winding terminals of the capacitive voltage transformer, and 1n and 2n represent the primary winding grounding terminals of the voltage transformer. · A single phase transformer with a residual voltage winding and two two times windings   It represents a single-phase transformer with a residual voltage winding and two two winding. The A represents the primary winding terminal of capacitive voltage transformer, and N represents the primary winding grounding terminal of voltage transformer. 1A1, 1A2, 2a and 2A2 respectively represent the two winding terminals of the capacitive voltage transformer, and 1n and 2n represent the primary winding grounding terminals of the voltage transformer. Da and DN represent the residual voltage terminal.   Detail III. Capacitor Voltage Transformer Testing 3.1 Insulation resistance measurement The insulation resistance should be measured by the main capacitor, the partial voltage capacitor and the one or two winding insulation resistance of the intermediate transformer. 3.2 Capacitance Measurement The purpose of the test is to determine whether the capacitance of the voltage divider has a change, and the capacitor is insulated without water and dampness.   3.3 Pressure swing ratio test The test transformer exerts high voltage as far as possible. Due to the rise effect in the test, the high voltage voltage must be measured at the high voltage end. The voltage transformer used must be level 0.1 or above to ensure the accuracy of the test results. After the voltage is applied at the high voltage side, the voltage of the low voltage side is measured in turn on the two side and in the auxiliary side, and the voltage ratio is compared with the pressure ratio of the nameplate. 3.4 Polar measurement The purpose of polar measurement is to check the mark of the nameplate. Test method: using DC method, CAR instantaneous addition of 1.5V battery power "+", "-" with "N", respectively, with a multimeter or mA DC or mV meter, pay attention to the polarity put right, A1, A0 "+" X1, XD "-" pointer in the power supply to the deflection of the "+" direction; open to "-" deflection. The test of polarity and pressure variable ratio of windings is usually done in hand over and after overhaul.   IV. Working Principle of Capacitive Voltage Transformer （CVT) There is a video about CVT:   This vidoe explained How Capacitor Voltage Transformer CVT works.Capacitor potential transformer concept is explained.What is high voltage measurement using capacitor type voltage transformer is explained. How to measure high voltage? Educational tutorial on electrical engineering 126 by G K Agrawal. The basic part of the capacitive voltage transformer is the capacitor voltage divider, and it also includes the electromagnetic parts such as the intermediate transformer, the compensating reactor, the damper and so on. Its principle connection is shown in the following picture,the picture shows capacitor voltage transformer wiring diagram capacitance divider is composed of main capacitor C1 and voltage divider capacitor C2 series. Without considering the electromagnetic part, the voltage is divided by capacitance. The voltage on C2 is the following formula: K is the partial voltage ratio. When the two ends of the C2 are connected to the two load, due to C1, C2 The basic part of the capacitive voltage transformer is the capacitor voltage divider, and it also includes the electromagnetic parts such as the intermediate transformer, the compensating reactor, the damper and so on. Its principle connection is given below.   The capacitor voltage divider is composed of the main capacitor C1 and the partial voltage capacitor C2 in series, without considering the electromagnetic part, then the voltage is divided according to the capacitance inverse ratio, and the voltage on the C2 is:   In this formula,K is the ratio of partial pressure When the two ends of C2 are connected to two loads, the larger capacitance internal impedance is due to the existence of C1 and C2, which makes UC2 smaller than the capacitance partial voltage. The larger the load current is, the greater the error is. In order to reduce the capacitance internal impedance, a compensatory reactor L can be connected in series, and the UC2 is not related to the load as much as possible. In fact, because the capacitor has loss, the reactor also has resistance, so that the internal impedance can not be zero, so when the load changes, there will always be error. In order to further reduce the effect of load current, the measuring instrument is connected to the divider after the intermediate transformer TV is boosted. When the two side transformer short circuit occurs, the resistance in the circuit and the total reactance reactor L after compensation are very small, several times the short-circuit current may reach the rated current, will produce a very high voltage resonance in L and C2, in order to prevent overvoltage caused by the breakdown of insulation in capacitor C2 parallel at both ends of the discharge gap F1. Capacitor voltage transformer with capacitance and nonlinear inductance (e.g. TV magnetizing inductance etc.), when the transformer side suddenly close or receive two side and eliminate the impact of sudden short circuit, overvoltage in the transient process may cause nonlinear inductor saturation, which excite ferroresonance overvoltage, such as harmonic 1/3 resonant.  Because the resistance is very small, the resonance will last for a long time, which will cause damage to voltage transformers, instruments and relays, and may lead to incorrect operation of the protective devices. Therefore, the damping resistance RD or damper is often installed on the two side of the capacitive voltage transformer to consume the resonant energy as soon as possible to suppress the ferroresonance. For a common capacitive voltage transformer, a resonant damper is used. It is the capacitance and the inductor in parallel and then added to the damping resistance. In UHV power grid, a capacitive voltage transformer often uses a fast saturation type damper, which is composed of a fast saturation reactance and a damping resistor.     Analysis V. Capacitive Voltage Transformer vs Inductive Voltage Transformer Inductive Voltage Transformers (IVT), are used for voltage metering and protection in high voltage network systems. They transform the high voltage into low voltage adequate to be processed in measuring and protection instruments secondary equipment, such as relays and recorders). A Voltage Transformer (VT) isolates the measuring instruments from the high voltage of the monitored circuit. VTs are commonly used for metering and protection in the electrical power industry. It’s a standard transformer available in the market for step-up or step-down voltages. The advantage is it can be used for high load current and provides isolation.   However,as we mentioned in the above,capacitor voltage transformer is a specialized circuit whose purpose is to convert a high voltage AC signal to lower voltage, usually used with very high input voltages, and a large ratio between input and output voltage. It's usually only used in cases where you're trying to extract a very small amount of power from a high-power circuit, usually for monitoring the high-power circuit. Its advatage is economical but there is no galvanic isolation.   Ⅵ. FAQ 1. What is the function of capacitor voltage transformer?A capacitor voltage transformer (CVT), also known as capacitor-coupled voltage transformer (CCVT), is a transformer used in power systems to step down extra high voltage signals and provide a low voltage signal, for metering or operating a protective relay.   2. Why is CVT used?One of the advantages of a CVT is its ability to continuously change its gear ratio. This means that no matter what the engine speed it, it is always performing at its peak efficiency. CVTs often offer better fuel economy as a result, especially when driving in the city. ... This is because the transmission never shifts.   3. What do you understand CVT and CCVT?Capacitor Voltage Transformer (CVT) or Capacitor Coupled Voltage Transformer (CCVT) is a switchgear device used to convert high transmission class voltage into easily measurable values, which are used for metering, protection, and control of high voltage systems.   4. Why are capacitors used in transformers?At too high common mode frequencies, the inevitable capacitive coupling in the transformer will cause some of the common mode signal on the input to show up as signal on the output. The capacitor provides a more serious connection to ground for AC, while the resistor only a weak connection for DC to avoid ground loops.   5. Why is CVT hated?Because CVTs tend to lock an engine into a specific RPM, generally a high and noisy RPM, making the whole experience very hard on the ears. Also, CVTs are generally tuned for fuel economy rather than performance, and most of the magazines out there are wannabe racecar drivers.   6. What is the function of capacitor voltage transformer?A capacitor voltage transformer (CVT), also known as capacitor-coupled voltage transformer (CCVT), is a transformer used in power systems to step down extra high voltage signals and provide a low voltage signal, for metering or operating a protective relay.

SummaryResearchers at TU Wien have succeeded in developing a method for the controlled manufacture of porous silicon carbide. Silicon carbide has significant advantages over silicon; it has greater chemical resistance and can therefore be used for biological applications, for example, without any additional coating required.Extremely fine porous structures with tiny holes – resembling a kind of sponge at nano level – can be generated in semiconductors. This opens up new possibilities for the realization of tiny sensors or unusual optical and electronic components. There have already been experiments in this area with porous structures made from silicon.To demonstrate the potential of this new technology, a special mirror that selectively reflects different colors of light has been integrated into a SiC wafer by creating thin layers with a thickness of approximately 70nm each and with different degrees of porosity. “There is a whole range of exciting technical possibilities available to us when making a porous structure with countless nano holes from a solid piece of a semiconductor material,” says Markus Leitgeb from the Institute of Sensor and Actuator Systems at TU Wien. Leitgeb developed the new material processing technology as part of his dissertation with Professor Ulrich Schmid in cooperation with CTR Carinthian Tech Research AG and sponsored by the Competence Centers for Excellent Technologies (COMET) program.“The porous structure influences the manner in which light waves are affected by the material. If we can control the porosity, this means we also have control over the optical refractive index of the material.” This can be very useful in sensor technology – for example, the refractive index of tiny quantities of liquid can be measured using a porous semiconductor sensor, thus allowing a reliable distinction between different liquids. Another attractive option from a technical and application-oriented perspective is to first make certain areas of the SiC wafer porous in a highly localized manner, before depositing a new SiC layer over these porous areas, and then causing the latter to collapse in a controlled manner – this technique produces microstructures and nanostructures which can also play a key role in sensor technology.  However, in all these techniques it is crucial that the appropriate starting material is selected. “Until now, silicon has been used for this purpose, a material with which we already have a lot of experience”, says Professor Schmid. Silicon also has significant drawbacks, however; under harsh environmental conditions, for example in extreme heat or in alkaline solutions, structures made of silicon are attacked and rapidly destroyed. Therefore, sensors made of silicon are often not suitable for biological or electrochemical applications. For this reason, at TU Wien, attempts have been made to achieve something similar with the semiconductor silicon carbide, which is biocompatible and considerably more robust from a chemical perspective. Some special tricks were required, however, in order to produce porous structures from silicon carbide. THE COLOR-SELECTIVE MIRRORFirst, the surface is cleaned, and then partially covered with a thin layer of platinum. The silicon carbide is then immersed in an etching solution and exposed to UV light, in order to initiate the oxidation processes. This causes a thin porous layer – initially 1μm thick – to form in these areas that are not coated with platinum. An electrical charge is then also applied in order to be able to precisely set the porosity and the thickness of the subsequent layers. Here, the first porous layer promotes the formation of the first pores when the electrical charge is applied.“The porous structure spreads from the surface further and further into the interior of the material”, explains Markus Leitgeb. “By adjusting the electrical charge during this process, we can control what porosity we want to have at a given depth.” In this way, it was possible to produce a complex layered structure of silicon carbide layers with higher and lower levels of porosity, which is finally separated from the bulk material by applying a high voltage pulse. The thickness of the individual layers can be selected such that the layered structure reflects certain light wavelengths particularly well or allows certain light wavelengths to pass through, resulting in an integrated, color-selective mirror. “We have thus demonstrated that our new method can be used to reliably control the porosity of silicon carbide on a microscopic scale”, says Ulrich Schmid. “This technology promises many potential applications, from anti-reflective coatings, optical or electronic components and special biosensors, through to resistant supercapacitors.” 

Summary Last days,I bought a new house and I am considering how to decorate it. when thinking about wall-lighting sconces.My project is to place an array of LED strips on the walls,covered with translucent(or in some cases,opaque!) Yeah,Plexiglas plates mounted a few centimetres away. That's the plan anyway...   Preparation At first, I need a 18W power supplies small enough to fit into an electrical box.Finally,I chose a power supply.This product could provide a full 1.5A without collapsing.However,upon opening the cases,the component temperatures after rumming at full-throttle for a new minutes suggested otherwise.The switching transistor,output rectifier,and output capacitor were all far too hot for comfort.I imagine the 18W spec is only valid for one day of use. Figure 1  The 12V 18W PSU. Notice the 100% efficiency (IN & OUT are both 18W), and  the dire warning not to touch the surface of the plastic case because of high temperature   I also bought one PSU from Aliexpress.They behave differently than the first batch. From an external vantage point, they’ll only supply 1.3A as opposed to the former 1.5A. The output voltage collapses to 8V at 1.5A.Take it apart, and further differences appear. Most noticeably, the 12V output capacitor does not egregiously overheat at, say, 1.3A. Sure enough, the part has “Low ESR” printed on the case. The previous caps don’t. Figure 2  PSUs from AliExpress (top) and another, forgotten source (bottom). Note the  convenient dates at the bottom of the boards. Manufacture has transitioned from phenolic to fiberglass   The design appears to be a simple self-oscillating circuit. I measured the switching frequency to be about 100 kHz. The 12V output caps are at the upper-right of each board. Though the legend says “1000µF 25V”, the installed caps are 470µF.   After discovering the output cap heat problem (but before getting the second PSU batch), I sourced a bagful of quality capacitors – 270µF @ 35V, still more than enough capacitance for this circuit, but with a high ripple-current rating and low ESR. Both of the boards above have these new parts installed. They run cool as a cucumber, versus the slight temperature rise of the second PSU caps, and of course, the extreme rise of the first ones. Figure 3  The PCB bottoms reveal other minor design changes in the newer boards – mainly exposed copper to pick up current-fortifying solder   I’m constantly struck by the strange state of affairs at this level of Chinese manufacture. Clearly, there is some thought and skill put into design and production, yet we still end up with stupidities, like unsuitable parts, or wishful-thinking specs. As I mentioned, other parts get hot too. The switching transistor can get toasty at higher loads, but it was the output rectifier I focused my measurements on. At 1.33A, free-air TC registered 90°C. At 1.2A, 86°C. Figure 4  My test setup here at EDN Labs. Note the many safety protocols employed on the bench   Enclosed in its case, in an electrical box, I don’t think I’ll want to pull more than 1.1A from these PSUs. Hopefully, that will be enough for my LED lighting. Other options: Squeeze two PSUs into a box (possibly swapping the case for some shrink wrap or electrical tape), or, cut a hole in the case so I can bend the rectifier out and heat-sink it to the electrical box! Hmm. We’ll see.   Result I didn't realize my plan until now.I am so tangle should choose which one? The last one,there is an absence of an AC line filter on the board.The former, at least, has a line filter, and even if they also don’t meet their output-current spec, they will certainly be better than the PSUs I’m using. But…they don’t fit into an electrical box.How do you think about my plan? Anyaway,I will attempt it again when I am free.  

Warm hints: The word in this article is about 1000 and the  reading time is about 6 minutes. MIT researchers found a way to triple the efficiency by using "topological" materials with special electronic properties. Although previous research has indicated that topological materials could be used to create efficient thermoelectric systems, little is known about how electrons in such topological materials can move in response to temperature differences to produce a thermoelectric effect. Researchers not only found that they can push the boundaries of this nanostructured material in a way that makes topological materials a good thermoelectric material,more so than conventional semiconductors like silicon,but also this could be a clean-energy way to help us use a heat source to generate electricity, which will lessen our release of carbon dioxide. NewsToday, thermoelectric devices are used for relatively low-power applications, such as powering small sensors along oil pipelines, backing up batteries on space probes, and cooling minifridges. Scientists hope to develop more efficient thermoelectric devices that will harvest heat produced as a byproduct of industrial processes and combustion engines and convert it into electricity. However, thermoelectric devices' power, or the amount of energy they can generate, is currently limited. "We discovered that we can push the limits of this nanostructured material in a way that makes topological materials a better thermoelectric material than traditional semiconductors like silicon," says Te-Huan Liu, a postdoctoral researcher in MIT's Department of Mechanical Engineering. "In the end, this could be a clean-energy way to help us use a heat source to generate electricity, which will lessen our release of carbon dioxide," Liu added. Liu is first author of the PNAS paper, which includes graduate students Jiawei Zhou, Zhiwei Ding, and Qichen Song; Mingda Li, assistant professor in the Department of Nuclear Science and Engineering; former graduate student Bolin Liao, now an assistant professor at the University of California at Santa Barbara; Liang Fu, the Biedenharn Associate Professor of Physics; and Gang Chen, the Soderberg Professor and head of the Department of Mechanical Engineering.A Path Travel Freely When a thermoelectric material is exposed to a temperature gradient — for example, one end is heated while the other is cooled — electrons begin to flow from the hot end to the cold end, resulting in an electric current. The greater the temperature difference, the more electric current and power are made. The amount of energy that can be produced is determined by the electron transport properties of a given material. Scientists have discovered that certain topological materials can be converted into efficient thermoelectric devices using nanostructuring, a technique used by scientists to create a material by patterning its features at the nanometer scale. Scientists believe that the thermoelectric benefit of topological materials stems from decreased thermal conductivity in their nanostructures. However, it is uncertain how this increase in efficiency relates to the material's inherent, topological properties.     Liu and his colleagues investigated the thermoelectric efficiency of tin telluride, a topological material considered to be a strong thermoelectric material, to try to address this issue. Tin telluride electrons also have unusual properties that resemble a class of topological materials known as Dirac materials. The researchers wanted to understand the effect of nanostructuring on the thermoelectric efficiency of tin telluride by simulating electron movement through the material. Scientists often use a calculation known as the "mean free path" to characterize electron transport. This is the average distance an electron with a given energy can freely travel within a material before being dispersed by different objects or defects in that material. Nanostructured materials resemble a patchwork of tiny crystals, each with its own boundary, known as grain boundaries, that separates one crystal from the next. As electrons come into contact with these limits, they scatter in a variety of ways. Electrons with long mean free paths scatter violently, similar to bullets ricocheting off a wall, whereas electrons with shorter mean free paths are much less affected. The researchers discovered that the electron properties of tin telluride have an important effect on their mean free paths in their simulations. They plotted the spectrum of electron energies in tin telluride against the related mean free paths and discovered that the resulting graph looked very different from that of most traditional semiconductors. In particular, for tin telluride and probably other topological materials, the findings indicate that higher-energy electrons have a shorter mean free path, while lower-energy electrons have a longer mean free path. The researchers then investigated how these electron properties influence the thermoelectric efficiency of tin telluride by essentially summing up the thermoelectric contributions from electrons with different energies and mean free paths. It turns out that the ability of a substance to conduct electricity, or produce a flow of electrons, under a temperature gradient is largely determined by the electron energy. They discovered that lower-energy electrons have a negative effect on the production of a voltage difference, and hence electric current. Since low-energy electrons have longer mean free paths, they can be dispersed more intensely by grain boundaries than high-energy electrons.Size DownGoing a step further in their simulations, the team experimented with the size of individual grains of tin telluride to see whether this had some impact on the movement of electrons under a temperature gradient. They discovered that raising the diameter of an average grain to around 10 nanometers, putting its boundaries closer together, increased the contribution of higher-energy electrons. Higher-energy electrons contribute much more to the material's electrical conduction with smaller grain sizes than lower-energy electrons because they have shorter mean free paths and are less likely to scatter against grain boundaries. As a result, a greater voltage difference can be produced. Furthermore, the researchers discovered that shrinking the average grain size of tin telluride to around 10 nanometers yielded three times the amount of electricity that the material would have produced with larger grains. Although the findings are based on simulations, Liu claims that researchers can achieve comparable results by synthesizing tin telluride and other topological materials and changing their grain size using a nanostructuring technique. Other researchers have proposed that shrinking the grain size of a material can improve its thermoelectric efficiency, but Liu claims that they have mostly assumed that the ideal size is much larger than 10 nanometers. "In our simulations, we discovered that we can shrink the grain size of a topological material far more than previously thought, and based on this principle, we can increase its performance," Liu says. Tin telluride is one of the topological materials that have yet to be discovered. If researchers can determine the optimal grain size for each of these materials, topological materials, according to Liu, can soon be a viable, more effective alternative to producing renewable energy. ConclusionLiu believes that topological materials are excellent for thermoelectric materials, and our findings indicate that this is a very promising material for potential applications. The Solid-State Solar Thermal Energy Conversion Center, an Energy Frontier Research Center of the United States Department of Energy, and the Defense Advanced Research Projects Agency contributed to this research (DARPA). Article From Proceedings of the National Academy of SciencesArticle Edited by kynix 

Warm hints: The word in this article is about 1000 and the  reading time is about 6 minutes.SummaryResearchers from Purdue University showed a range of concepts and technologies about semiconductor industry at international IEDM 2016 Conference in Dec. 2016. Looking forward to the future of semiconductor,which concepts included innovations to extend the performance of today's silicon-based transistors,along with entirely new types of nanoelectronic devices to complement and potentially replace conventional technology in future computers. This is a device is made from the semiconductor germaniumIssueIn the conference,researchers said,"For the past 50 years, ever more electronic devices envelop us in our day-to-day life, and electronic-device innovation has been a major economic factor in the U.S. and world economy," said Gerhard Klimeck, a professor of electrical and computer engineering and director of Purdue's Network for Computational Nanotechnology in the university's Discovery Park. "These advancements were enabled by making the basic transistors in computer chips ever smaller. Today the critical dimensions in these devices are just some 60 atoms thick, and further device size reductions will certainly stop at small atomic dimensions." New technologies will be needed for industry to keep pace with Moore's law, an observation that the number of transistors on a computer chip doubles about every two years, resulting in rapid progress in computers and telecommunications. It is becoming increasingly difficult to continue shrinking electronic devices made of conventional silicon-based semiconductors, called complementary metal-oxide-semiconductor (CMOS) technology, said Muhammad Ashraful Alam, Purdue University's Jai N. Gupta Professor of Electrical and Computer Engineering. "As transistors are becoming smaller they are facing a number of challenges in terms of increasing their performance and ensuring their reliability," he said. Purdue researchers presented five papers proposing innovative designs to extend CMOS technology and new devices to potentially replace or augment conventional transistors during the annual International Electron Devices Meeting (IEDM 2016) Dec. 5-7 in San Francisco. The conference showcases the latest developments in electronic device technology. Purdue researchers are in the  laboratoryIntegrated circuits, or chips, now contain around 2 billion transistors. The more devices that are packed onto a chip, the greater the heating, with today's chips generating around 100 watts per square centimeter, comparable to that of a nuclear reactor. "As a result, self-heating has become a fundamental concern that hinders performance and can damage transistors, and we are making advances to address it," Alam said. Two of the IEDM conference papers detail research to suppress self-heating and enhance the performance of conventional CMOS chips. The remaining papers deal with new devices for future computer technologies that require lower power to operate, meaning they would not self-heat as significantly. "We are not only working to extend the state-of-art of traditional technology, but also to develop next-generation transistor technologies," Alam said. Transistors are electronic switches that turn on and off to allow computations using the binary code of ones and zeros. A critical component in transistors, called the gate, controls this switching. As progressively smaller transistors are designed, however, this control becomes increasingly difficult because electrons leak around the ultra-small gate. One of the conference papers focuses on a potential solution to this leakage: creating transistors that are surrounded by the gate, instead of the customary flat design. Unfortunately, enveloping the transistor with a gate causes increased heating, which hinders reliability and can damage the device. The researchers used a technique called submicron thermo-reflectance imaging to pinpoint locations of excessive heating. Another paper details a potential approach to suppress this self-heating, modeling how to more effectively dissipate heat by changing how the transistor connects to the complex circuitry in the chip.The three remaining papers propose next-generation devices: networks of nanomagnets, extremely thin layers of a material called black phosphorous and "tunnel" field effect transistors, or FETs. Such technologies would operate at far lower voltages than existing electronics, generating less heat. "You want to use as low a voltage as possible because that reduces power dissipation and if you can reduce power dissipation the battery of your cell phone will last longer, you can do more computing with a smaller amount of power and you will be able to cram more functional elements into a given area," Klimeck said. The tunnel FETS could potentially reduce power consumption by more than 40 times. "Reducing power consumption by a factor of 40 would be a huge development," Klimeck said. Another conference paper details research to develop devices made of black phosphorous, which might one day replace silicon as a semiconductor in transistors. Findings showed the devices can pass large amounts of current with ultra-low resistance while demonstrating good switching performance, said Peide Ye, the Richard J. and Mary Jo Schwartz Professor of Electrical and Computer Engineering. "We have demonstrated the highest performance of this kind of 2-D device," Ye said.Peide Ye,the Richard J. and Mary Jo Schwartz Professor of Electrical and Computer EngineeringDevices made from the material also could bring new types of optical and chemical sensors. The devices were created using a technique called chemical vapor deposition in research performed at Purdue's Birck Nanotechnology Center. Future research will include efforts to create smaller black phosphorous devices, Ye said. A fifth paper details how networks of nanomagnets could serve as the building blocks of future computers. Findings show the networks mimic Ising networks - named after German physicist Ernst Ising - which harness mathematics to solve complex probabilistic problems. The nanomagnet networks might be used to draw from huge databases to perform demanding jobs in areas ranging from business and finance, to health care and scientific research. The conventional approach to performing big data computations is through new software running on CMOS devices. However, nanomagnet networks represent a different approach: developing an entirely new type of hardware for the feat, said Zhihong Chen, an associate professor of electrical and computer engineering.The nanomagnet arrays are potential building blocks for probabilistic computer hardware has been proved. Researchers are still in unremitting efforts to creat new semiconductor technologies.  Article Provided by Purdue UniversityArticle edited by kynix