On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

A Hybrid Optimization Approach of Single Point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with Principal Component Analysiss

We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with Principal Component Analysis(PCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with PCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.

Obsolescence optimization of electronic and mechatronic components by considering dependability and energy consumption

Nowadays, rapid technological progress influences the dependability of equipments and also causes rapid obsolescence. The mechatronic and electronic equipment components are mostly affected by obsolescence. A new challenger unit possesses identical functionalities, but with higher performances. This work aims to find the optimal number of components which should be replaced by new-type units, under budgetary constraints. In this work, the new challenger unit is characterized by lower energy consumption and the optimization steps are based on genetic algorithm (GA). The result shows the importance of this type of replacement in order to economize energy consumption and to deal with obsolescence.

RS Components和Allied Electronics现可供货树莓派3计算模块

Electrocomponents plc集团旗下的贸易品牌RS Components（Rs）和Allied Electronics发布了基于树莓派3架构的最新版本树莓派计算模块。新款树莓派3计算模块（CM3）是针对开发嵌入式系统的专业工程师而设计，可安装于标准的DDR2 SODIMM插座，提供与树莓派3相同的基本处理能力。

Experimental Study on Heat Transfer Enhancement of Natural Circulation Liquid Cooling System for Electronic Component

The present research is an experimental study on heat transfer characteristics of a natural circulation cooling system for electronic components. A smooth chip and two micro-pin-finned chips were tested. The chip is mounted on the base of a rectangular horizontal duct located at the bottom of 250 mm high natural circulation loop.FC-72 is used as a coolant. The test conditions are set that the operation pressure of experimental system is 1. 013× 105 Pa, the flow rate of FC-72 is 150 g/min and the subcoolings are 10 K, 25 K and 35 k, respectively. Effect of the subcooling on nucleate boiling and critical heat flux(CHF) were investigated. The results show that subcoolingis found to significantly affect CHF for all chips and micro-pin-finned chips sharply enhanced the boiling heat transfer, CHF of micro-pin-finned chips are 2.5～3 times as large as that of smooth chip at the same subcooling.

Data Masking for Chinese Electronic Medical Records with Named Entity Recognition

With the rapid development of information technology,the electronifi-cation of medical records has gradually become a trend.In China,the population base is huge and the supporting medical institutions are numerous,so this reality drives the conversion of paper medical records to electronic medical records.Electronic medical records are the basis for establishing a smart hospital and an important guarantee for achieving medical intelligence,and the massive amount of electronic medical record data is also an important data set for conducting research in the medical field.However,electronic medical records contain a large amount of private patient information,which must be desensitized before they are used as open resources.Therefore,to solve the above problems,data masking for Chinese electronic medical records with named entity recognition is proposed in this paper.Firstly,the text is vectorized to satisfy the required format of the model input.Secondly,since the input sentences may have a long or short length and the relationship between sentences in context is not negligible.To this end,a neural network model for named entity recognition based on bidirectional long short-term memory(BiLSTM)with conditional random fields(CRF)is constructed.Finally,the data masking operation is performed based on the named entity recog-nition results,mainly using regular expression filtering encryption and principal component analysis(PCA)word vector compression and replacement.In addi-tion,comparison experiments with the hidden markov model(HMM)model,LSTM-CRF model,and BiLSTM model are conducted in this paper.The experi-mental results show that the method used in this paper achieves 92.72%Accuracy,92.30%Recall,and 92.51%F1_score,which has higher accuracy compared with other models.

Feature Extraction of Sectorial Scan Image of Thick-Walled Electron Beam Welding Seam Based on Principal Component Analysis

A feature extraction method was proposed to sectorial scan image of Ti-6Al-4V electron beam welding seam based on principal component analysis to solve problem of high-dimensional data resulting in timeconsuming in defect recognition. Seven features were extracted from the image and represented 87. 3% information of the original data. Both the extracted features and the original data were used to train support vector machine model to assess the feature extraction performance in two aspects: recognition accuracy and training time. The results show that using the extracted features the recognition accuracy of pore,crack,lack of fusion and lack of penetration are 93%,90.7%,94.7% and 89.3%,respectively,which is slightly higher than those using the original data. The training time of the models using the extracted features is extremely reduced comparing with those using the original data.

Comparison of Algorithms for an Electronic Nose in Identifying Liquors

When the electronic nose is used to identify different varieties of distilled liquors, the pattern recognition algorithm is chosen on the basis of the experience, which lacks the guiding principle. In this research, the different brands of distilled spirits were identified using the pattern recognition algorithms （principal component analysis and the artificial neural network）. The recognition rates of different algorithms were compared. The recognition rate of the Back Propagation Neural Network （BPNN） is the highest. Owing to the slow convergence speed of the BPNN, it tends easily to get into a local minimum. A chaotic BPNN was tried in order to overcome the disadvantage of the BPNN. The convergence speed of the chaotic BPNN is 75.5 times faster than that of the BPNN.

Influence of Component Size on the Corrosion Behavior of Ti6Al4V Alloy Fabricated by Electron Beam Powder Bed Fusion

The electrochemical behavior of Ti-6Al-4V with 1 mm and 16 mm thickness prepared by electron beam powder bed fusion(EB-PBF)was investigated in phosphate buffered saline.Electrochemical results showed that EB-PBF Ti-6Al-4V with a larger component size was more resistant to corrosion compared to the smaller component,because of less acicularαʹphase content and moreβphase content.As a non-equilibrium phase in the“high-energy state”,αʹphase has a greater susceptibility to corrode and reduces the corrosion resistance of the material,whileβphase improves corrosion resistance of titanium alloys.The results show that the phase composition has a more significant effect on the corrosion performance than the grain size.

A review on electronically conducting polymers for lithium-sulfur battery and lithium-selenium battery:Progress and prospects

Lithium-sulfur(Li-S) batteries and lithium-selenium(Li-Se) batteries,as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities,have become the hotspots of current researches.Besides,elemental S(Se) raw materials are widely sourced and their production costs are both low,which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development.However,poor conductivity of elemental S/Se and the notorious "shuttle effect" of lithium polysulfides(polyselenides) severely hinder the commercialization of Li-S/Se batteries.Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide(polyselenide) about electronically conducting polymer,some of the above thorny problems have been effectively alleviated.The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries,which involves polyaniline(PANI) polypyrrole(PPy),and polythiophene(PTh) with its derivatives,e.g.polyethoxythiophene(PEDOT) and poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS).Finally,the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers,but also looks forward to the development prospects of them,which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.

Design and performance test of miniature capillary pumped loop for electronics cooling

Considering two characteristics of compact heat dissipation room and high heat flux, a novel miniature capillary pumped loop (MCPL) for electronics cooling was proposed. MCPL consists of evaporator, condenser, vapor and liquid line dissipates heat by boiling and condensation of working fluids with no extra power consumption. Working fluid circulation is ensured by vapor pressure and capillary head. Saturated wick screens vapor and liquid, and ensures one-way flow of working fluid with no extra valve. In order to promote heat dissipation capacity of MCPL, the intensified boiling and condensation structures are embedded into evaporator and condenser respectively, which are useful to increasing boiling and condensation efficiency. Startup and run characteristics are tested by experiments in the condition of different power inputs and working fluids. MCPL is capable of dissipating 80 W of thermal energy and keeping the bottom substrate temperature of evaporator at 80 ℃.

Voltammetric Identification of Motor Oils Using Electronic Tongue on Carbon-Paste Electrode Basis

Viscous organic liquids are common products which are used in human life. The motor oils used to lubricate the moving parts of internal combustion engines present an important group of these substances. Timeous monitoring of motor oil quality allows providing durability of engine. For this purpose the problem of designing of express sensor devices for identification of motor oils and other viscous organic liquids using inexpensive voltammetric methods of analysis is solved. In this paper, the results of motor oils identification using electronic tongue on the carbon-paste electrode basis with motor oils as a binder have been presented. The possibility of univocal identification of individual samples of motor oils has been shown.

ArcGIS^TMand Principal Component Analysis of Probe Data to Micro-Map Minerals in Round Top Rare Earth Deposit

Rare earth elements (REEs), especially heavy rare earth elements (HREEs), are in demand for their current and emerging applications in advanced technologies. Here we perform computer-driven micro-mapping at the millimeter scale of the minerals that comprise Round Top Mountain, in west Texas, USA. This large rhyolite deposit is enriched in HREEs and such other critical elements as Li, Be, and U. Electron probe microanalysis of 2 × 2 mm areas of thin sections of the rhyolite produced individual maps of 16 elements. These were superimposed to generate a 16-element composition at each pixel. Principal components analysis of elements at each pixel identified the specific mineral at that site. The pixels were then relabeled as the appropriate minerals, thereby producing a single mineral map. The overall mineral composition of the 7 studied samples compared favorably with prior analyses of the Round Top deposit available in the literature. Likewise the range of porosity in the maps was consistent with that of previous direct measurements by water saturation. This new statistical and GIS-based technique provides a robust and unbiased approach to electron microprobe mapping. The study further showed that the high-value yttrofluorite grains exhibited little tendency to cluster with other late-stage trace minerals and that the samples extended the previously documented overall homogeneity of the deposit at field scale to this microscopic scale.

Structural components of the nuclear body in nuclei of Allium cepa cells

Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and function are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 microm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level confirmed that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.

干燥方式对铁棍山药片挥发性风味成分的影响

采用顶空固相微萃取结合气相色谱-质谱联用技术(HS-SPME-GC-MS)和电子鼻,分别测定热风干燥、微波干燥、真空干燥、真空冷冻干燥、联合干燥5种干燥方式加工的铁棍山药片的挥发性风味成分,并结合主成分分析,研究干燥过程中山药片风味的变化。结果表明,在5种干燥方式制得的山药片中,共检出95种挥发性成分,主要包括烃类、醛类、酮类、醇类、酯类、苯类和杂环化合物等。壬醛、癸醛、2,6,10-三甲基十四烷、香叶基丙酮是山药片中的主要风味物质。热风干燥、真空干燥、微波干燥所得山药片的主要挥发性物质有烃类、苯类和醛类;真空冷冻干燥、联合干燥所得山药片的主要挥发性物质有烃类、醛类和酮类。电子鼻检测结果表明,5种干燥方式制得的山药片风味存在一定差异,其中热风干燥和真空干燥所得山药片的风味在醇、部分芳香族化合物上具有相似性,真空冷冻干燥山药片与其它干燥方式山药片的风味差异主要是含氮化合物、含硫化合物。这与GC-MS分析结果一致。根据主成分分析法建立了山药片香气品质评价模型,得出联合干燥方式制得的山药片综合得分最高,香气品质最好,其次为真空冷冻干燥、微波干燥、热风干燥、真空干燥。

星载微波部件微放电阈值的改进多粒子蒙特卡罗计算方法

星载微波部件的微放电效应是导致航天器谐振类设备失谐、噪声电平抬高、输出功率下降,甚至影响通信信道乃至整个微波传输系统彻底失效的瓶颈问题之一。在设计阶段对星载微波部件微放电效应进行精准的评估是减少地面反复试验,避免延误研制周期的重要手段。为了进一步改善现有蒙特卡洛方法的计算准确度问题,文中提出了一种精度更高的计算星载微波部件微放电阈值的蒙特卡罗方法,该方法对参与微放电过程的初始电子进行了动态调整,采用四阶龙格-库塔法推进微波部件中电子的运动轨迹,基于Furman模型描述电子与微波表面相互作用的二次电子发射过程,按照碰撞电子产生的实际二次电子个数及对应能量参与碰撞时刻后的微放电过程,该多粒子-多碰撞过程更加客观、准确地表征了微放电效应发生的物理过程。以平板传输线和同轴传输线为例,文中所提出的方法相对于已有的蒙特卡罗方法计算精度显著提升,同时计算效率优于商用CST的粒子模拟结果。

紫外及电子束辐照对远志中黄曲霉毒素及有效成分的影响

[目的]探究电子束及紫外辐照对远志中黄曲霉毒素的降解率及有效成分的影响。[方法]利用高效液相色谱法研究不同辐照剂量的电子束、不同含水量、不同时间的紫外辐照对远志中黄曲霉毒素的降解率及有效成分的影响。[结果]电子束辐照剂量越大,远志中黄曲霉毒素的降解率越高。经10 kGy电子束辐照处理,远志中黄曲霉毒素AFB_(1)、AFB_(2)、AFG_(1)、AFG_(2)的降解率分别为19.27%、19.64%、15.62%、15.14%;6 kGy辐照处理含水量28%的远志中AFB_(1)、AFB_(2)、AFG_(1)、AFG_(2)的降解率均最高;紫外辐照时间越长,远志中黄曲霉毒素的降解率越高。黄曲霉毒素的降解率随着辐照距离的增加而减小。经不同辐照处理后远志中细叶远志皂苷、远志口三酮、3,6′-二芥子酰基蔗糖含量变化不显著。[结论]采用电子束辐照结合调整远志含水量及紫外辐照处理均能对远志中黄曲霉毒素进行有效降解,且对有效成分影响不大。

密封电子元器件与装置多余物检测发展综述

密封电子元器件与装置作为航天系统中的重要组成部分,具有高精密性、高可靠性以及高复杂性的典型特点,而多余物问题是严重影响其高可靠性的主要因素之一。随着航天技术的快速发展,多余物检测技术也在不断改进与深入。该文以认识多余物、控制多余物产生以及检测多余物为主线,围绕多余物的防控方法、检测方法、检测标准进行综合论述。着重分析了检测方法中的颗粒碰撞噪声检测(PIND)方法,分别从小型元器件多余物检测、中大型装置多余物检测两个角度,针对现有研究进展逐一进行了详细的介绍。在此基础上,结合现有国内多余物检测研究的现状,针对多余物检测的难点与未来发展趋势进行归纳,并提出了期望与目标。

基于深度学习的电解电容识别与极性检测

针对工程中印刷电路板(PCB)上的电解电容不易识别、极性难以检测的问题,研究了一种基于深度学习的电解电容识别与极性检测方法。对于电容检测问题,提出了一种基于YOLOv5的改进算法,该算法在YOLOv5的骨干(backbone)融合Swin Transformer模块,提升模型的特征提取能力,在颈部融合了双向金字塔网络(BiFPN)模块,提高了网络的特征融合能力;对于电容极性检测,提出了一种语义分割结合形态学处理的方法,该方法能够分割电容基圆区域与极性区域然后有效检测电解电容的极性方向。实验结果表明,电容的识别精度达到96.9%,电容的分割精度达到93.9%,极性方向检测准确率达到99.1%,相比于目前电解电容极性检测较好的方法,所提方法有较好的鲁棒性,满足检测需求。

电致变色材料在智能运动服装中的应用

为实现电致变色材料与柔性器件的集成,设计出高性能、低成本和舒适性的智能运动服装。采用文献综述和比较分析的研究方法,对电致变色材料的基本原理、分类以及优越性进行了论述;分析了电致变色材料在智能运动服装中的温度调节功能和运动状态监测功能等功能与应用。电致变色材料在智能运动服装领域展现巨大潜力,但电致变色材料在智能运动服装实际应用中仍面临一些挑战问题,如能耗高、响应速度慢和循环稳定性差等,提出针对性的解决方案,可为电致变色材料在智能运动服装中的应用提供可行性参考。