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Prototype of space-borne LTT module and its ground tests

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science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 1179-1186页

作者： WANG YuanMing YANG FuMin HUANG PeiCheng ZHANG ZhongPing CHEN WanZhen shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Graduate University Chinese Academy of SciencesBeijing 100049China Xi’an Institute of Surveying and Mapping Xi’an 710054China

In order to develop the technique of Laser Time Transfer(LTT) ,shanghai Astronomical Observatory has built a prototype of space-borne LTT module. The performance of the LTT module and the results of ground tests are discussed in the paper. The average precision of time difference between two rubidium clocks measured by laser pulses is 196 ps,and the uncertainty of measurement for the relative frequency differences is 1.2×10-13/2800 s.

关键词： Laser Time Transfer(LTT) clock difference time synchronization Satellite Laser Ranging(SLR)

Generating Virtual Images for Multi-view Video

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Chinese Journal of Electronics 2017年第4期26卷 810-813页

作者： ZHANG Lijun LI Yue ZHU Qiuyu LI Mingqi New Media Wireless Research Center Shanghai Advanced Research Institute Chinese Academy of Sciences School of Communication and Information Engineering Shanghai University

As for the research in the Free view television(FTV) and stereo video areas, the accurate multi-view video capture is a expensive precondition. We present a virtual multi-view video capture system based on Open GL programming. By using this system, a researcher may create arbitrary 3D scenes, and capture images with depth maps by setting up multiple virtual cameras, whose intrinsic and extrinsic parameters can be imported from or exported to the outside. We conducted several experiments within it to perform camera calibration, depth estimation and view-points synthesis. The system has been demonstrated to be a powerful tool for evaluation of stereo video algorithms.

关键词： Multi-view video Virtual realistic Com puter vision Sterio video Free view television(FTV)

Controllable large-scale processing of temperature regulating sheath-core fibers with high-enthalpy for thermal management

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Nano Materials science 2024年第3期6卷 337-344页

作者： Ziye Chen Zexu Hu Shining Chen Senlong Yu Liping Zhu Hengxue Xiang Meifang Zhu Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China College of Mechanical and Engineering Donghua UniversityShanghai201620China

Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.

关键词： Thermal management Hybrid fibers Polyamides Bicomponent melt spinning Temperature regulating fibers

Geometric dilution of precision for GPS single-point positioning based on four satellites

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Journal of Systems Engineering and Electronics 2008年第5期19卷 1058-1062,F0003页

作者： Wang Huihui Zhan Xingqun Zhang Yanhua Inst. of Aerospace science & technology Shanghai Jiaotong Univ. Shanghai 200240 P. R. China

To improve the positioning accuracy in GPS point positioning, the geometric dilution of precision （GDOP） including HDOP, VDOP, TDOP, PDOP is commonly considered. The properties of the DOP for the GPS satellite navigation system are studied and the coordinate system is improved in order to decrease the amount of variables. In the end, by simulation and discussing the results, the corresponding conclusions are presented.

关键词： GPS dilution of precision GDOP navigation simulation.

Polymer complexation for functional fibers

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science china(Technological sciences) 2019年第6期62卷 931-944页

作者： HUANG WenTao LIU DeZhong LI JieFu ZHU LiPing YANG ShuGuang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Center for Advanced Low-dimension Materials Donghua University

Polymer complex is a polymer association of different polymers with good miscibility resulting from the relatively strong intermolecular interactions or stereo match effect between polymer chains. Polymer complexes have been utilized in various fields, such as food, biomedical, cosmetic, and pharmacy. Fiber is one of the most important material forms, and shaping polymer complex into fiber will further extend its applications. This review briefly introduces the fundamentals of polymer complex, and then demonstrates the main approaches to produce polymer complex fibers(PCFs). Followed by, the modification of fibers with polymer complexes is presented. Finally, the applications of PCFs and the polymer complex modified fibers are provided, and the prospect of polymer complexation for fibers is discussed properly.

关键词： interpolymer complex functional fiber polyelectrolyte complex hydrogen-bonded polymer complex fiber modification

High-capacity Bi_(2)O_(3) anode for 2.4 V neutral aqueous sodium-ion battery-supercapacitor hybrid device through phase conversion mechanism

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Journal of Energy Chemistry 2022年第2期31卷 605-615页

作者： Mingze Xu Yanli Niu Xue Teng Shuaiqi Gong Lvlv Ji Zuofeng Chen shanghai Key Lab of Chemical Assessment and Sustainability School of Chemical Science and EngineeringTongji UniversityShanghai 200092China School of Materials science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina

Aqueous battery-supercapacitor hybrid devices(BSHs)are of great importance to enrich electrochemical energy storage systems with both high energy and power ***,further improvement of BSHs in aqueous electrolytes is greatly hampered by operating voltage and capacity *** from the conventional intercalation/de-intercalation mechanism,Bi_(2)O_(3) implements charge storage by a reversible phase conversion ***,taking Bi_(2)O_(3) electrode with wide potential window(from-1.2 to 1 V *** calomel electrode)and high capacity as battery-type anode,we propose that the overall performance of aqueous BSHs can be greatly upgraded under neutral *** paring with stable layer-structuredδ-MnO_(2) cathode,a sodium-ion Bi_(2)O_(3)//MnO_(2) BSH with an ultrahigh voltage of 2.4 V in neutral sodium sulfate electrolyte is developed for the first *** hybrid device exhibits high capacity(~215 C g^(-1) at 1 mA cm^(-2)),relatively long lifespan(~77.2%capacity retention after 1500 cycles),remarkable energy density(71.7 Wh kg^(-1)@400.5 W kg^(-1))and power density(3204.3 W kg^(-1)@18.8 Wh kg^(-1)).Electrochemical measurements combining a set of spectroscopic techniques reveal the reversible phase conversion between bismuth oxide and metallic bismuth(Bi_(2)O_(3)?Bi0)through Bi^(2+) transition phase in neutral sodium sulfate solution,which can deliver multielectron transfer up to 6,leading to the high-energy *** work sheds light on the feasibility of using Bi_(2)O_(3) electrode under neutral condition to address the issue of narrow voltage and low capacity for aqueous BSHs.

关键词： Bismuth oxide Phase conversion High voltage High capacity Battery-supercapacitor hybrid devices

Investigation on the fabrication of the 3rd harmonic superconducting cavity for the SSRF storage ring

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Chinese Physics C 2009年第9期33卷 792-797页

作者：马震宇马广明于海波毛冬青封自强侯洪涛刘建飞 shanghai Institute of Applied Physics CAS Graduate University of Chinese Academy of sciences shanghai Key Lab of Cryogenics & Superconducting RF technology

A third harmonic superconducting niobium cavity has been proposed for installation in the shanghai Synchrotron Radiation Facility （SSRF） storage ring to improve the Touschek lifetime. In order to investigate the feasibility of the superconducting cavity fabrication indigenously and the possibility to master the fabrica tion techniques, cavities were fabricated from copper and niobium sheets by deep drawing and electron-beam welding, and a series of measurements, such as resonant frequency, shape dimensions and wall thickness, were carried out during this process. After analysis of various problems existing in the fabrication process, technique improvements were proposed, and finally the precise shape as designed and resonant frequency within 1.2 MHz were achieved for the new completed cavities. In addition, full annealing was finally proved to be a good cure for niobium sheets＇ tearing up during deep drawing. By fabricating niobium cavities successfully, some problems to the next step were cleared. This paper introduces the process of cavity fabrication and its technique improvements towards forming, and the initial vertical test result of niobium cavity is also presented.

关键词： SSRF higher harmonic cavity superconducting radio frequency fabrication technology

Microstructure, Residual Strain and Stress Corrosion Cracking Behavior in 316L Heat-Affected Zone

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Acta Metallurgica Sinica(English Letters) 2016年第9期29卷 848-858页

作者： Hong-Liang Ming Zhi-Ming Zhang Peng-Yuan Xiu Jian-Qiu Wang En-Hou Han Wei Ke Ming-Xing Su Key Laboratory of Nuclear Materials and Safety Assessment Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China University of Chinese Academy of sciences Beijing 100049 China shanghai Research Center for Weld and Detection Engineering Technique of Nuclear Equipment Shanghai 201306 China

Austenitic stainless steels are usually chosen to make many components of nuclear power plants （NPPs）. However, their microstructure in the heat-affected zone （HAZ） will change during the welding process. Some failures of the weld joints, mainly stress corrosion cracking （SCC）, have been found to be located in the HAZ. In this research, the microstructure, micro-hardness, residual strain and SCC behavior at different locations of the 316L HAZ cut from a safeend dissimilar metal weld joint were studied. However, traditional optical microscope observation could not find any microstructural difference between the HAZ and the base metal, higher residual strain and micro-hardness, and higher fraction of random high-angle grain boundaries were found in the HAZ than in the base metal when studied by using electron back-scattering diffraction scanning and micro-hardness test. What＇s more, the residual strain, the microhardness and the fraction of random grain boundaries decreased, while the fraction of coincidence site lattice grain boundaries increased with increasing the distance from the fusion boundary in 316L HAZ. Creviced bent beam test was applied to evaluate the SCC susceptibility at different locations of 316L HAZ and base metal. It was found that the HAZ had higher SCC susceptibility than the base metal and SCC resistance increased when increasing the distance from the fusion boundary in 316L HAZ.

关键词： Austenitic stainless steels Heat.affected zone Microstructure EBSD Residual strain Stresscorrosion cracking

Analysis of delamination in thin film electrodes under galvanostatic and potentiostatic operations with Li-ion diffusion from edge

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Acta Mechanica Sinica 2013年第3期29卷 348-356页

作者： Bo Lu Yi-Cheng Song Zhan-Sheng Guo Jun-Qian Zhang shanghai Institute of Applied Mathematics and Mechanics Shanghai University Department of Mechanics Shanghai University shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University

Progressive delamination driven by Li-ion diffusion in elastic disk-like thin film electrodes of Li-ion batteries is modeled based on the cohesive model. Axisymmetric diffusion model is considered under both galvanostatic and potentiostatic operations. The effect of edge diffusion on the delamination process is evaluated. It is found that the diffusion from edge leads to an earlier delamination initiation. The edge effect is significant for active disks with a small aspect ratio, but negligible for the case of large aspect ratio. The edge diffusion is weaker in the potentiostatic operation than in the galvanostatic operation.

关键词： Lithium-ion battery · Thin film electrode · De-lamination · Diffusion