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Dynamic modeling of twin roll casting AZ41.magnesium alloy during hot compression processing

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Transactions of Nonferrous Metals Society of China 2010年第B07期20卷 513-518页

作者：王敏王守仁 S.BKANG J.H.CHO 王砚军 school of Materials Science and {1. Shandong University school of Mechanical {1. University of Jinan Korea Institute of Materials Science 66 Sangnam-dong

A dynamic material model of Mg-4.51.l-1.1.Zn-0.5Mn-0.5Ca(AZ41.mass fraction,%)magnesium alloy was put *** results show that the dynamic material model can characterize the deformation behavior and microstructure evolution and describe the relations among flow stress,strain,strain rates and deformation *** analysis shows the validity of the proposed *** model predicts that lower deformation temperature and higher strain rate cause the sharp strain hardening. Meanwhile,the flow stress curve turns into a steady state at high temperature and lower strain *** moderate temperature of 350 ℃and strain rate of 0.01.s-1.are appropriate to this alloy.

关键词： AZ41.alloy flow stress deformation behavior dynamic model twin-roll casting hot compression

Failure mechanism of EB-PVD thermal barrier coatings on NiAl substrate

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中国有色金属学会会刊：英文版 2007年第4期17卷 811-815页

作者：李合非郭洪波宫声凯 school of Materials Science and {1. Beihang University

Yttria stabilized zirconia(YSZ) was deposited on the line cut β-NiAl substrate by electron-beam physical vapour deposition(EB-PVD), and the cyclic oxidation behaviors of thermal barrier coatings on β-NiAl substrate were investigated in 1.h thermal cycles at 1.200 ℃ in air. The results show that the samples fail after 80?1.0 cycles. Sub-interface cavitations in the substrate develop due to depletion of Al in forming thermally grown oxides(TGOs). The collapse and closing up of cavities result in the ragged YSZ/TGO/substrate interface. Since the specific crack trajectories are quite sensitive to local geometry, cracks along the YSZ/TGO/substrate interfaces ultimately lead to YSZ spallation.

关键词：电子束-物理气相沉积镍铝基底氧化钇氧化锆循环氧化热障涂层失效机理

Carbon nanotube-based photothermal membrane for efficient cold air heating and removal of particulate matter and airborne bacteria

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Green Carbon 2024年第1期2卷 101-108页

作者： Weichao Dong Lina Huang Xiangju Song Yan Zhang Mengke Liu Zhenzhen Ren Long Pang Hui Peng Heqing Jiang Key Laboratory of Biobased Materials Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China school of Material Science and {1. Henan Polytechnic UniversityJiaozuo 454003China Shandong Energy Institute Qingdao 266101China Qingdao New Energy Shandong Laboratory Qingdao 266101China University of Chinese Academy of Sciences Beijing 101408China College of Chemistry and Pharmaceutical engineering HuangHuai UniversityZhumadian 463000China

Indoor heating results in high energy consumption and severe atmospheric *** the development of solar air heaters provides a sustainable route for indoor thermal comfort,such heaters still face challenges in terms of adequate heat exchange and filtering of atmospheric *** by solar-driven interfacial evaporation,we propose a multifunctional carbon nanotube-based photothermal membrane for efficient cold air heating and purification via *** nanotubes endow the membrane with high light absorption and thermal conversion capabilities,thereby sufficiently heating the approaching cold *** the hierarchical structure formed by phase inversion,the thin upper skin of the composite membrane intercepts micropollutants via the size-sieving effect,whereas the finger-like pores and interpenetrating macrovoids inside the membrane ensure that the heated clear air passes through quickly.A proof-of-principle experiment indicated a cold airflow of 1.L/min across the membrane,yielding a temperature increase of ca.37℃ as well as a PM 2.5 rejection always higher than 93%.Further antibacterial experiments demonstrated that the membrane effectively removed airborne *** multifunctional carbon nanotube-based photothermal membrane with specific microstructures not only improves the indoor living quality but also provides a sustainable development scheme to coordinate the relationship among energy utilization,building heating,and air purification.

关键词： Indoor heating Carbon nanotubes Multifunctional photothermal membrane Hierarchical structure Particulate matter

Study on Ferroelectric and Dielectric Properties of La-Doped CaBi_4Ti_4O_(1.)-Based Ceramics

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Journal of Rare Earths 2007年第2期25卷 168-172页

作者：郑夏莲黄新友高春华 school of Materials Science and {1. Jiangsu University

Lanthanum doped bismuth layer structured ferroelectrics （BLSFs） Ca1.- x LaxBi4 （Ti0.9W0. 1.）4O1. （ x = 0, 0.2, 0.3, 0.4, 0.6） ceramics were prepared by solid-state reaction method. X-ray diffraction （XRD） patterns showed that single phase was formed when x = 0 - 0.6. The effects of La^3＋ doping on dielectric, piezoelectric and ferroelectric properties of Ca1.xLaxBi4（Ti0.9W0.1.4O1. ceramics were studied. Ca0.7La0.3Bi4（Ti0.9W0.1.4O1. ceramic had optimal properties, its dielectric constant was 1.6.85, dielectric loss was 0.0063, piezoelectric strain constant was 1. pc·N^-1. remanent polarization was 1..1.C·cm^-2 and coercive field was 1.8 kV·cm^-1. SEM micrographs showed that the grains of CaBi4Ti4O1.-based ceramics were plate-like. The results of energy spectrum analysis （EDS） showed that La^3＋ incorporation could increase Bi/Ca ratio.

关键词： bismuth layer structure ceramics La-doped ferroelectric rare earths

An approach to the optical interconnect made in standard CMOS process

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Journal of Semiconductors 2009年第5期30卷 113-116页

作者：余长亮毛陆虹肖新东谢生张世林 school of Electronic Information {1. Tianjin University

A standard CMOS optical interconnect is proposed, including an octagonal-annular emitter, a field oxide, metal 1.PSG/BPSG-metal 2 dual waveguide, and an ultra high-sensitivity optical receiver integrated with a fingered P＋/N-well/P-sub dual photodiode detector. The optical interconnect is implemented in a Chartered 3.3-V 0.35-μm standard analog CMOS process with two schemes for the research of the substrate noise coupling effect on the optical interconnect performance： with or without a GND-guardring around the emitter. The experiment results show that the optical interconnect can work at 1.0 kHz, and it is feasible to implement optical interconnects in standard CMOS processes.

关键词： optical interconnect standard CMOS emitter waveguide ultra high-sensitivity

Construction of a novel kind of expression plasmid by homologous recombination in Saccharomyces cerevisiae

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Science China(Life Sciences) 2005年第4期48卷 330-336页

作者： CHEN Xiangling, YUAN Hanying, HE Wei, HU Xianghua, LU Hong & LI Yuyang State Key Laboratory of Genetic engineering, {1. of Life Sciences, Fudan University, Shanghai 200433, China 1. State Key Laboratory of Genetic engineering School of Life Sciences Fudan University 200433 Shanghai China

Based on a previously used plasmid pHC1., a new plasmid pHC1.R was con-structed. Cutting plasmid pHC1.R with proper restriction enzymes, the resulting larger DNA fragment pHC1.R’ was co-transformed with a PCR amplified expression cassette of human IFNα2b into yeast. By means of the homologous sequences at both ends of two DNA fragments, a novel expression plasmid pHC1.R-IFNα2b was formed via homologous recombination in the yeast. Compared with pHC1.-IFNα2b, the expression plasmid pHC1.R-IFNα2b was smaller in size and in absence of antibiotic resistant gene. The stability and copy number of pHC1.R- IFNα2b were greatly increased and the expression level of heterologous protein was improved. As the derivatives of pHC1.R, a series of recombination expression vectors pHRs containing different combination of expression elements were developed. This led to a rapid and powerful method for cloning and expressing of different genes in yeast.

关键词： homologous recombination Saccharomyces cerevisiae expression plasmid.

In-situ measurement of magnetic field gradient in a magnetic shield by a spin-exchange relaxation-free magnetometer

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Chinese Physics B 2015年第6期24卷 253-258页

作者：房建成王涛张红李阳蔡洪炜 school of Instrument Science and Opto-Electronics {1. Science and Technology on Inertial LaboratoryBeihang University school of Instrument Science and {1. Southeast University

A method of measuring in-situ magnetic field gradient is proposed in this paper. The magnetic shield is widely used in the atomic magnetometer. However, there is magnetic field gradient in the magnetic shield, which would lead to additional gradient broadening. It is impossible to use an ex-situ magnetometer to measure magnetic field gradient in the region of a cell, whose length of side is several centimeters. The method demonstrated in this paper can realize the in-situ measurement of the magnetic field gradient inside the cell, which is significant for the spin relaxation study. The magnetic field gradients along the longitudinal axis of the magnetic shield are measured by a spin-exchange relaxation-free （SERF） magnetometer by adding a magnetic field modulation in the probe beam＇s direction. The transmissivity of the cell for the probe beam is always inhomogeneous along the pump beam direction, and the method proposed in this paper is independent of the intensity of the probe beam, which means that the method is independent of the cell＇s transmissivity. This feature makes the method more practical experimentally. Moreover, the AC-Stark shift can seriously degrade and affect the precision of the magnetic field gradient measurement. The AC-Stark shift is suppressed by locking the pump beam to the resonance of potassium＇s D1.line. Furthermore, the residual magnetic fields are measured with σ＋- and σ--polarized pump beams, which can further suppress the effect of the AC-Stark shift. The method of measuring in-situ magnetic field gradient has achieved a magnetic field gradient precision of better than 30 pT/mm.

关键词： spin-exchange relaxation-free atomic magnetometer magnetic field gradient magnetic shield,AC-Stark shift

Reaction of Bis(Methylcyclopentadienyl) Lanthanide Amido Complex with n-Hexyl isocyanate-Synthesis and Characterization of {(MeC_5H_4)_2YbOC(NPh_2)N(n-hexyl)}_2

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Journal of Rare Earths 2005年第6期23卷 653-656页

作者：郭华东姚英明邓明宇张勇沈琪 school of Chemistry and Chemical {1. Suzhou University Suzhou 215006 China school

Bis （methylcyclopentadienyl） lanthanide amido complex （MeCp） 2YbNPh2 （THF） reacted with n-hexyl isocyanate （n-nexylNCO） in 1.1.molar ratio to give {（MeC5H4）2Yb[OC（NPh2）N（n-hexyl）] }2（1.. Complex 1.was characterized by elemental analyses and X-ray diffraction. The title complex belongs to trigonal system and R-3 space group. Its unit cell parameters are a =2.9533（1.） nm, b =2.9533（1.） nm, c = 1.5873（6） nm, V= 1..9896（80） nm^3, Z =9, Dc= 1.562 mg·m^-3, μ = 3.536 mm^-1.Mo Kα）, F（000） =5670, R =0.034, Rw =0.064. It is a dimeric structure with two symmetrical bridged oxygen atoms. Nitrogen atom is coordinated to the ytterbium atom to form a tricyclic backbone. The coordination number of ytterbium is 9. The whole molecule shows central symmetry.

关键词： inorganic chemistry cyclopentadienyl lanthanide amido complex n-hexyl isocyanate insertion reaction crystal structure rare earths

Challenges and countermeasures of interaction in autonomous vehicles

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Science China(Information Sciences) 2019年第5期62卷 5-7页

作者： Deyi LI Meng LIU Fei ZHAO Yu LIU State Key Laboratory of Software Development Environment School of Computer Science and EngineeringBeihang University Chinese Academy of engineering school of Transportation Science and {1. Beihang University

Autonomous vehicles can bring changes into ways of traveling, traffic, and even production modes [1..At present, the majority of researches [2] on autonomous vehicles are limited in perception, planning, decision-making and other calculation front,while interactive cognitive perspective is barely looked into. The interactive sector involved in self-driving is rather sophisticated [3]. However,

关键词： Challenges and countermeasures of interaction in autonomous vehicles