Nonlinear optical and electrical effects associated with a lack of spatial inversion symmetry allow direction-selective propagation and transport of quantum particles, such as photons
and electrons
. ...The most common example of such nonreciprocal phenomena is a semiconductor diode with a p-n junction, with a low resistance in one direction and a high resistance in the other. Although the diode effect forms the basis of numerous electronic components, such as rectifiers, alternating-direct-current converters and photodetectors, it introduces an inevitable energy loss due to the finite resistance. Therefore, a worthwhile goal is to realize a superconducting diode that has zero resistance in only one direction. Here we demonstrate a magnetically controllable superconducting diode in an artificial superlattice Nb/V/Ta
without a centre of inversion. The nonreciprocal resistance versus current curve at the superconducting-to-normal transition was clearly observed by a direct-current measurement, and the difference of the critical current is considered to be related to the magnetochiral anisotropy caused by breaking of the spatial-inversion and time-reversal symmetries
. Owing to the nonreciprocal critical current, the Nb/V/Ta
superlattice exhibits zero resistance in only one direction. This superconducting diode effect enables phase-coherent and direction-selective charge transport, paving the way for the construction of non-dissipative electronic circuits.
This paper presents 2‐channel time‐multiplexed chopper instrument amplifier for better gain accuracy and mismatch. Mostly, the current‐attenuated feedback resistor with a duty‐cycled resistor is ...adopted for boosting the RC time constant. It can achieve the high pass corner frequencies between 10 Hz and 320 Hz by a 3‐bit digitally controlled resistor bank of the attenuator. As a result, the instrument amplifier achieves 0.6% gain accuracy between two time‐multiplexed channels, 100 dB CMRR, ‐40 dB crosstalk, and noise densities of 50nV/√Hz. It is implemented in a 180‐nm CMOS technology. It occupies a 0.6 mm*0.6 mm chip area and consumes 1.5μA current consumption from a 1.8 V supply for each channel.
Aiming at the problems of low efficiency and low accuracy caused by manual defect detection of electronic components, FCN, SegNet/DeconvNet and DeepLab and other deep learning technologies are ...studied. Using Caffe, Keras, PyTorch and other frameworks, an automatic defect identification system for electronic components is developed to distinguish qualified products from unqualified ones, so as to realize intelligent defect detection of electronic components. At the same time, the detection accuracy rate is greatly improved, and the quality of electronic components is guaranteed.
This article first analyzes the verification of Xinyan electronic components, including functional verification, performance verification, and process verification. Secondly, the author elaborated on ...the current status of use of the newly developed electronic component verification methods, such as low applicability of domestic components, poor authority of verification specifications, and low integration of development and application. This paper studies the overall verification process analysis, application verification method analysis, verification effect evaluation analysis, verification information sharing evaluation, etc., in order to improve the accuracy of verification results and the rationality of electronic components distribution.
The thermal control of electronic components is aimed at ensuring their use in a temperature range compatible with their performances. This paper presents an experimental study of the behavior of ...phase change materials (PCMs) as the cooling system for electronic devices. Four configurations are used to control the increase in the system temperature: pure PCM, PCM in a silicone matrix, PCM in a graphite matrix and pure PCM in a system of fins. Thermo-physical properties of different PCMs are determined and found to be desirable for application in this study. Solid liquid interface visualization and temperature evolution are employed to understand the mechanism of heat transfer during the different stages. Results indicated that the inclusion of PCM can lower component increase temperature and extends twice the critical time of the heat sink. The use of Graphite matrix filled by PCM showed more improvement on system thermal performance than silicon matrix. Also, for the same fraction of copper, it was found that incorporating long copper fins with suitable spacing into PCM, can enhance heat distribution into PCM leading to longer remain component temperature below the critical limit. This work therefore shows that the combination of PCM and long, well-spaced fins presents an effective means for thermal control of electronic devices.
•Study on thermal performance of different PCM based heat sink in electronic cooling.•Examination of heat transfer mechanism into heat sink for different conditions.•Graphite matrix shows more efficiency than silicon.•Inclusion PCM can reduce temperature increasing.•Heat sink with longer well spaced fins can extend longer the critical time.
The present study involves the experimental investigation of the heat sink aided with nanoparticle-enhanced phase change material and heat pipe for the passive cooling of electronic components, ...thereby increasing the reliability of the working system. In this study, RT-35HC is used as the base phase change materials along with the incorporation of Graphene oxide nanoparticles (0.003 mass% and 0.005 mass%) for different heating loads i.e., 1 KW m
−2
, 1.5 KW m
−2
and 2.5 KW m
−2
. Results illustrated that after the charging phase, heat sink aided with nanoparticle-enhanced phase change material and heat pipe has shown the best results for lower heating loads of 1 KW m
−2
, 1.5 KW m
−2
, respectively, by showing the temperature reduction of 29.53% and 34.06% (at 1 KW m
−2
) and also 36.29% and 36.45% (at 1.5 KW m
−2
) for 0.003 mass% and 0.006 mass%, respectively. For high heat flux of 2.5 KW m
−2
, phase change material/heat pipe-aided heat sink has shown the best combination i.e., showing a temperature reduction of 42.81%, respectively, whereas, for both the concentrations i.e., 0.003 mass% and 0.006 mass%, the reduction in the peak temperature of heat sink at the end of the charging process is 32.95% and 37.54%. Hence, RT-35HC-based nanoparticle-enhanced phase change material composite-aided heat sinks are best recommended for lower power levels whereas, at higher power levels the thermal conductivity reduces due to the particles agglomeration.
The broad-band reflection spectra of YB.sub.6 and YbB.sub.6 hexaborides with Jahn-Teller instability of the boron cage have been measured at room temperature. An optical conductivity analysis has ...revealed, along with the Drude electronic components, heavily overdamped collective modes, which are notable in YB.sub.6 for high dielectric contributions, DELTAepsilon = 2000-5700. The fraction of nonequilibrium charge carriers in YB.sub.6, which is at the boundary of structural instability in the hexaboride family, reaches 85-90%, whereas this fraction in doped YbB.sub.6 semiconductor is not higher than 25%. It has been shown that unlike the predictions of the topological Kondo insulator model, the surface "metallization" in Yb.sup.2+B.sub.6 crystals can be explained by additional doping of a surface layer with Yb.sup.3+ ions.
Improper operating temperature will degrade the performances of electronic components, Li-ion batteries and photovoltaic (PV) cells, which calls for a good thermal management system. In this paper, ...specific attention is paid to the thermal management systems based on the phase change materials (PCMs). Performances of the PCM-based thermal management systems for each kind of these three devices along with the type of PCM used, thermal properties of that kind of PCM, like phase change temperature, enthalpy of phase change and thermal conductivity are discussed. Discussion in detail on techniques to improve the thermal conductivity of PCMs is made because of its crucial influence. Advanced-structure heatsinks with multi-layer PCMs and hybrid passive heatsinks combined with active cooling are also introduced. The PCM-based thermal management system is powerful in ensuring electronic devices, Li-ion batteries and photovoltaic cells working safely and efficiently.
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