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Boron nitride silicone rubber composite foam with low dielectric and high thermal conductivity

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Chinese Journal of Chemical Engineering 2024年第4期68卷 224-230页

作者： Shuilai Qiu hang wu Fukai Chu Lei Song College of Safety and Ocean Engineering China University of Petroleum-BeijingBeijing 102249China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026China

Silicone rubber(SR)is widely used in the field of electronic packaging because of its low dielectric *** this work,the porosity of the SR was improved,and the dielectric constant of the SR foam was reduced by adding expanded microspheres(EM).Then,the thermal conductivity of the system was improved by combining the modified boron nitride(f-BN).The results showed that after the f-BN was added,the dielectric constant and dielectric loss were much lower than those of pure ***-sized modified boron nitride(f-mBN)improved the dielectric and thermal conductivity of the SR foam better than that of nano-sized modified boron nitride(f-nBN),but f-nBN improved the volume resistivity,tensile strength,and thermal stability of the SR better than *** the mass ratio of f-mBN and fnBN is 2:1,the thermal conductivity of the SR foam reaches the maximum value of 0.808 W·m^(-1)·K^(-1),which is 6.5 times that before the *** heat release rate and fire growth index are the lowest,and the improvement in flame retardancy is mainly attributed to the high thermal stability and physical barrier of f-BN.

关键词： Foam Composites Dielectric properties Thermal conductivity Mechanical properties Flame retardant

Study of Pseudogap in Underdoped Cuprate

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Communications in Theoretical Physics 2001年第7期36卷 91-94页

作者： LOU Ping wu hang-Sheng Department of Physics Anhui University Hefei 230039 China Department of Physics University of Science and Technology of China Hefei 230026 China

A mean-field spin-density wave (SDW) analysis of pseudogap in the underdoped cuprates is proposed on the dependence of the energy gap which mimics the pseudogap near (π, 0) point at least. It implies that the pseudogap structure near (π, 0) is not sensitive to the long-range order and will survive leading to the pseudogap phenomenon in the underdoped metallic phase. On the other hand, in the long-range ordering antiferromagnetic region, the mean-field SDW theory holds and the pseudogap structure predicated by the theory should be observable experimentallyv. Then one prediction is that the pseudogap would smoothly extrapolate between itinerant antiferromagnetic phase and underdoped metallic phase.

关键词： high-temperature superconductors, pseudogap, underdoped cuprates, mean-field SDW analysis

A framework for the fusion of visual and tactile modalities for improving robot perception

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Science China(Information Sciences) 2017年第1期60卷 145-156页

作者： Wenchang Zhang Fuchun SUN hang wu Haolin YANG The State Key Laboratory of Intelligent Technology and Systems Tsinghua University

Robots should ideally perceive objects using human-like multi-modal sensing such as vision, tactile feedback, smell, and hearing. However, the features presentations are different for each modal sensor. Moreover,the extracted feature methods for each modal are not the same. Some modal features such as vision, which presents a spatial property, are static while features such as tactile feedback, which presents temporal pattern,are dynamic. It is difficult to fuse these data at the feature level for robot perception. In this study, we propose a framework for the fusion of visual and tactile modal features, which includes the extraction of features, feature vector normalization and generation based on bag-of-system(BoS), and coding by robust multi-modal joint sparse representation(RM-JSR) and classification, thereby enabling robot perception to solve the problem of diverse modal data fusion at the feature level. Finally, comparative experiments are carried out to demonstrate the performance of this framework.

关键词： multi-modal fusion robot perception vision tactile classification

Classical Theory of Hot-Electron Transport in Electric and Magnetic Fields

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Communications in Theoretical Physics 2002年第3期38卷 370-374页

作者： WENG Ming-Qi wu hang-Sheng Department of Physics University of Science and Technology of China Hefei 230026 China Department of Physics University of Science and Technology of China Hefei 230026 China

Balance equation approach to the hot-electron transport in electric and magnetic fields is *** balance equations are re-derived from the Boltzmann equation. A new expression for the distribution function isreported in the present paper. It is homogeneous steady solution of the Boltzmann equation in constant relaxation timeapproximation. It holds when ωocτ < i or ωc < Te. As an example, the mobility of 2D electron gas in the GaAs-AlGaAsheterojunction is computed as a function of electric field and magnetic field.

关键词： hot-electron transport, balance equation, Boltzmann equation, mobility

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Asynchronous Brain-Computer Interface Shared Control of Robotic Grasping

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Tsinghua Science and Technology 2019年第3期24卷 360-370页

作者： Wenchang Zhang Fuchun Sun hang wu Chuanqi Tan Yuzhen Ma the Department of Computer Science and Technology Tsinghua University State Key Lab.of Intelligent Technology and Systems Institute of Medical Support Technology Academy of Military Sciences Drugs Control of PAP

The control of a high Degree of Freedom(DoF) robot to grasp a target in three-dimensional space using Brain-Computer Interface(BCI) remains a very difficult problem to solve. Design of synchronous BCI requires the user perform the brain activity task all the time according to the predefined paradigm; such a process is boring and fatiguing. Furthermore, the strategy of switching between robotic auto-control and BCI control is not very reliable because the accuracy of Motor Imagery(MI) pattern recognition rarely reaches 100%. In this paper, an asynchronous BCI shared control method is proposed for the high DoF robotic grasping task. The proposed method combines BCI control and automatic robotic control to simultaneously consider the robotic vision feedback and revise the unreasonable control commands. The user can easily mentally control the system and is only required to intervene and send brain commands to the automatic control system at the appropriate time according to the experience of the user. Two experiments are designed to validate our method: one aims to illustrate the accuracy of MI pattern recognition of our asynchronous BCI system; the other is the online practical experiment that controls the robot to grasp a target while avoiding an obstacle using the asynchronous BCI shared control method that can improve the safety and robustness of our system.

关键词： asynchronous Brain-Computer Interface (BCI) shared control motor imagery robotic grasping

A NEW T_(c)FORMULA FOR SUPERCONDUCTORS

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Chinese Physics Letters 1984年第1期1卷 7-10页

作者： wu hang-sheng WENG Zheng-yu Department of Physics University of Science and Technology of ChinaHefei

A formula of the critical temperature for superconductors with smallλis derived from the Eliashberg equation1.

关键词： equation superconductors critical

Lifetime prediction and failure analysis of organic coatings by EIS

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 455-458页

作者： YAN Rui wu hang MA Shi-ning XU Bin-shi Surface Engineering Research Institute of CMES Chinese Mechanical Engineering Society Beijing 100072 China Surface Engineering Research Institute of CMES Chinese Mechanical Engineering Society Beijing 100072 China Surface Engineering Research Institute of CMES Chinese Mechanical Engineering Society Beijing 100072 China Surface Engineering Research Institute of CMES Chinese Mechanical Engineering Society Beijing 100072 China

Organic coatings are widely used to control the corrosion of steel structure. The anticorrosive property of these coatings depends on their barrier properties, making a separation between the corrosive medium and the substrate. But unavoidable completely small pores, cracks and other defects in organic coatings may cause ions, water, gases, and other corrosive species penetrate and distribute in the coatings, causing accumulation and swelling of coatings, so leading to the degradation of coatings. In addition, water affects the permeation of oxygen and other corrosive medium, consequently the presence of such substances at coating-metal interface promotes corrosion of metal substrate. So the absorbability of the coatings to water may be one of the most important factors in undercoating corrosion. In recent years, electrochemical impedance spectroscopy (EIS) has been established and frequently used as a non-destructive testing method for assessing the performance of organic coatings, especially for the determination of the water content in organic coatings, since the capacitance of the coatings is sensitive to the penetration of water. So from EIS it can extract a wealth of information on the electrochemical corrosion of coated steels, especially, it can be utilized to assess organic coatings used under particular surroundings. The principle, methods and application of EIS on evaluating life-span and analyzing failure mechanism of organic coatings are also introduced briefly. Combining other analysis techniques such as XRD, SEM and FTIR with electrochemical technique, it will blaze a way in studying degradation mechanism of organic coatings and estimating their lifetime.

关键词： organic coatings lifetime prediction failure analysis electrochemical impedance spectro scopy

The effect of cataract surgery on sleep quality:a systematic review and Meta-analysis

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International Journal of Ophthalmology(English edition) 2017年第11期10卷 1734-1741页

作者： Ling Zheng Xiao-hang wu Hao-Tian Lin State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangzhou 510060Guangdong ProvinceChina Jieyang People’s Hospital Jieyang Affiliated HospitalSun Yat-sen UniversityJieyang 522000Guangdong ProvinceChina

AIM： To evaluate the effect of cataract surgery on sleep quality and to compare the difference between ultravioletblocking clear intraocular lens（UVB-IOL） and blue-filtering intraocular lens（BF-IOL） ***： Electronic search was performed of PubM ed, MEDLINE, Embase and the Cochrane Library up to January 2016. Studies were eligible when they evaluated the sleep quality before and after cataract surgery by Pittsburgh sleep quality index（PSQI）. A random/fixed-effects Metaanalysis was used for the pooled estimate. Heterogeneity was assessed with the I2 test. RESULTS： Six studies were selected from 5623 references. Cataract surgery significantly reduced the PSQI scores at postoperative 0-3 mo [mean difference（MD） =-0.62, 95%CI：-1.14 to-0.11, P=0.02, I2=66%] and 3-12 mo（MD=-0.32, 95%CI：-0.62 to-0.02, P=0.04, I2=0）, respectively. Considering different intraocular lens（IOL） implantations, relative postoperative PSQI reduction was found for both UVB-IOL and BF-IOL, but a significant reduction was detected only for UVB-IOL. No significant difference was found with the effect of BF-IOL vs UVB-IOL on sleep quality. CONCLUSION： This study found that cataract surgery significantly improved the PSQI score-derived subjective sleep quality irrespective of the IOL type implanted. These findings highlight a substantial benefit of cataract surgery on systemic health with photoreceptive restoration in addition to visual acuity improvements.

关键词： cataract surgery intraocular lens implantation sleep quality

Kinetic and Thermodynamic Studies on Adsorption of Cu2＋, Pb2＋, Methylene Blue and Malachite Green from Aqueous Solution Using AMPS-modified Hazelnut Shell Powder

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Chemical Research in Chinese Universities 2017年第1期33卷 112-118页

作者： LU Linlin JIANG Xiaojun JIA Lian AI Tian wu hang School of Chemical Engineering University of Science and Technology Liaoning Anshan 114051 P. R. China School of Chemistry and Life Science Anshan Normal University Anshan 114005 P. R. China

A high-efficiency, low-cost and environmem-friendly 2-acrylamide-2-methyl propane sulfonic acid （AMPS）-modified hazelnut-shell-based adsorbent（AHS） was synthesized and used to adsorb Cu2＋, Pb2＋, methylene blue（MB） and malachite green（MG） from aqueous solutions. The AHS was characterized by means of SEM, BET, FTIR and XPS. Different experimental parameters were evaluated in batch adsorption experiments to determine the optimal adsorption conditions. Adsorption kinetics shows that the adsorption rate is well represented by the pseudo- secend-order rate model, and the Langmuir model gives the best fit adsorption isotherm. The Langmuir maximum adsorption capacities were fotmd to be 21.14 mg/g for Cu2＋, 32.74 mg/g for Pb2＋, 68.03 mg/g for MB and 263.16 mg/g for MG, respectively, while the adsorption capacities could be maintained above 90% even after ten adsorp- tion-desorption cycles. The experimental results show that AHS could be applied to treat both industrial and munici- pal wastewaters.

关键词： Hazelnut shell Kinetic Thermodynamic Adsorption Metal ion Dye