检索结果-南通市图书馆

Loading direction dependence of asymmetric response of pyramidal slip in rolled AZ31 magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第10期11卷 3634-3641页

作者： Yuzhi Zhu Dewen Hou kaixuan chen Zidong Wang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Micron School of Materials Science and Engineering Boise State UniversityBoiseID 83725United States Center for Nanoscale Materials Argonne National LaboratoryLemontIL 60439United States

Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping *** work focuses on the pyramidal slip responses of rolled AZ31 magnesium alloy under two loading conditions,compressive and tensile loading along the normal *** the condition where the compressive loading direction is closely parallel to the c-axis of the unit cell,tensile twinning and basal slips are prohibited, dislocations then active and tend to accumulate at grain boundaries and form dislocation ***,these dislocations exhibit zigzag morphologies,which result from the cross-slip from {10■1} first-order pyramidal plane to {11■2} second-order pyramidal plane,then back to {10■1} first-order pyramidal *** the condition where tensile twins are prevalent,{10■1} first-order and {11■2} second-order pyramidal dislocations are favorable to be *** types of dislocations behave climb-like dissociations onto the basal plane,forming zigzag dislocations.

关键词： Magnesium pyramidal slip Asymmetry Cross-slip

Porous polymeric ligand promoted copper-catalyzed C-N coupling of(hetero)aryl chlorides under visible-light irradiation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2021年第1期64卷 17-21页

作者： Erfei Wang kaixuan chen Yinan chen Jiawei Zhang Xinrong Lin Mao chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of Education and Yunnan ProvinceSchool of Chemical Science and TechnologyYunnan UniversityKunming 650091China

A porous polymeric ligand(PPL)has been synthesized and complexed with copper to generate a heterogeneous catalyst(Cu@PPL)that has facilitated the efficient C-N coupling with various(hetero)aryl chlorides under mild conditions of visiblelight irradiation at 80°C(58 examples,up to 99%yields).This method could be applied to both aqueous ammonia and substituted amines,and is compatible to a variety of functional groups and heterocycles,as well as allows tandem C-N couplings with conjunctive ***,the heterogeneous characteristic of Cu@PPL has enabled a straightforward catalyst separation in multiple times of recycling with negligible catalytic efficiency loss by simple filtration,affording reaction mixtures containing less than 1 ppm of Cu residue.

关键词： polymeric catalyst heterogeneous catalysis photocatalysis C-N coupling

Platinum-Catalyzed Asymmetric Ring-opening Reaction of Oxabenzonorbornadiene with Terminal Alkynes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2014年第7期32卷 613-618页

作者： Yuhua Long Han Jiang Zhifu Zou kaixuan chen Yali Fang School of Chemistry and Environment South China Normal UniversityGuangzhouGuangdong 510006China

A novel platinum-catalyzed asymmetric ring-opening reaction of oxabenzonorbornadiene with terminal alkynes is *** reaction affords optically active cis-2-alkynyl-1,2-dihydronaphthalen-1-ols in moderate yields with good enantioselectivity in the presence of catalytic amounts of Pt(COD)Cl_(2)/(S)-BINAP and an excess of zinc *** products were obtained exclusively with the relative cis-configuration of the ring substituents and the prevalent(1R,2S)-configuration of the stereocenters,as determined by single crystal X-ray diffraction analysis.

关键词： platinum-catalyzed asymmetric catalysis ring-opening reaction oxabenzonorbornadiene terminal alkyne

Scaling of ac susceptibility and the nonlinear response function of high-temperature superconductors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2005年第1期48卷 14-25页

作者： chen kaixuan NING Zhenhua XU Hengyi QI Zhi LU Guo WANG Furen YIN Daole Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China Department of Physics Peking University Beijing 100871 China

The amplitude-dependent ac susceptibility of high-temperature superconductors is shown to obey some empirical scaling relations. We try to analyze this behavior by extending a dc nonlinear response function of mixed state to the ac cases. The derived equations for critical current and ac susceptibility x(T) agree with the scaling relations of experimental data.

关键词： high-temperature superconductor, ac susceptibility, scaling law, nonlinear response.

Four-channel CWDM transmitter chip based on thin-film lithium niobate platform

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2022年第11期43卷 22-28页

作者： kaixuan chen Gengxin chen Ziliang Ruan Xuancong Fan Junwei Zhang Ranfeng Gan Jie Liu Daoxin Dai Changjian Guo Liu Liu Guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Academy of Advanced OptoelectronicsSouth China Normal UniversityHigher-Education Mega-CenterGuangzhou 510006China National Center for International Research on Green Optoelectronics South China Normal UniversityGuangzhou 510006China State Key Laboratory for Modern Optical Instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityHangzhou 310058China State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou 510006China Jiaxing Key Laboratory of Photonic Sensing&Intelligent Imaging Intelligent Optics&Photonics Research CenterJiaxing Research InstituteZhejiang UniversityJiaxing 314000China

Multi-lane integrated transmitter chips are key components in future compact optical modules to realize high-speed optical ***-film lithium niobate(TFLN)photonics have emerged as a promising platform for achieving high-performance chip-scale optical *** a coarse wavelength-division multiplexing(CWDM)devices using fabrication-tolerant angled multimode interferometer structure and high-performance electro-optical modulators,we demonstrate monolithic on-chip four-channel CWDM transmitter on the TFLN platform for the first *** four-channel CWDM transmitter enables high-speed transmissions of 100 Gb/s data rate per wavelength channel(i.e.,an aggregated date rate of 400 Gb/s).

关键词： transmitter lithium niobate coarse wavelength-division multiplexing electro-optic modulator

Making Sense of Reconstruction Models for Human Intention Detection

在线全文

学校读者我要写书评

暂无评论

China Communications 2020年第4期17卷 180-192页

作者： Wei Liang Dalin Zhang Xigang Yuan kaixuan chen School of Computer Science and Engineering University of New South South2052 NSWAustralia Department of Computer Science and Engineering Changshu Institute of TechnologyChangshu 215500China Business School Jiangsu Normal UniversityXuzhou 221116China

Movement intention recognition paves the path to developing Brain-Computer Interface(BCI)*** research mostly focuses on questions like“which hand is intended to move”.While answering questions like“whether a hand is intended to move”is more desirable for widely real-world applications,because we cannot continuously perform intention tasks during usage,and the gap periods may cause unintended operation resulting in system ***,this kind of intention detection task is more difficult,since for a“whether”problem,it is hard to know what the“not”situation is and consequently to acquire training samples for the“not”***,the occurrence of genuine intentions is comparatively scarce and unexpected,making the intention detection task hard and *** tackle this problem,we propose a Reconstruction-based Intention Detection(RID)framework,which utilises a reconstruction model to represent a high-level abstraction of EEG signals and leverages the reconstruction errors to determine“whether”there is a movement *** framework is not only theoretically flexible and robust to any sophisticated real-world scenarios but also hand-crafted feature and domain knowledge *** experiments on detecting movement intention tasks with different reconstruction models demonstrate the promising performance of the proposed reconstruction intention detection framework.

关键词： intention consuming Reconstruction

Four-channel CWDM device on a thin-film lithium niobate platform using an angled multimode interferometer structure

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2022年第1期10卷 8-13页

作者： GENGXIN chen ZILIANG RUAN ZONG WANG PUchenG HUANG CHANGJIAN GUO DAOXIN DAI kaixuan chen LIU LIU State Key Laboratory for Modern Optical Instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityHangzhou 310058China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Academy of Advanced OptoelectronicsSouth China Normal UniversityHigher-Education Mega-CenterGuangzhou 510006China National Center for International Research on Green Optoelectronics South China Normal UniversityGuangzhou 510006China

A compact and high-performance coarse wavelength-division multiplexing(CWDM) device is introduced with a footprint of 2.1 mm × 0.02 mm using an angled multimode interferometer structure based on a thin-film lithium niobate(TFLN) *** demonstrated device built on a 400 nm thick x-cut TFLN shows ultra-low insertion losses of <0.72 *** 3 dB bandwidths are 12.1 nm for all channels,and cross talks from adjacent channels are better than 18 *** peak wavelength positions comply with the CWDM standard with a channel spacing of 20 *** filter bandwidth of the proposed CWDM device can be tuned by adjusting the structural *** demonstrated CWDM device will promote future realization of multi-channel and multi-wavelength transmitter chips on TFLN.

关键词： interferometer channel CWDM

Effect of Heat Treatment on Microstructure and Mechanical properties of high strength low alloy(HSLA)steel

在线全文

学校读者我要写书评

暂无评论

Research and Application of Materials Science 2019年第2期1卷 31-38页

作者： Siyuan ZHAO kaixuan chen Yalikun·WUQIKUN Xiaohua chen Zidong WANG School of Science and Engineering University of Science and Technology BeijingBeijingChina State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijingChina

In this paper,a Fe-based Mn-Ni–Cr–Mo high strength low alloy(HSLA)steel was prepared by using Vacuum melting,following by hot rolling with 78%deformation and various heat treatment *** were characterized by optical microscope(OM),scanning electron microscope(SEM)equipped with energy dispersive *** tests were *** direct quenching(Q)from 860℃,the samples were subjected to secondary quenching(L)at different intercritical temperatures within the two-phase region and various tempering temperatures(T).Results show that QLT treatment increases elongation and decreases yield ratio compared with conventional quenching and tempering process(QT).The optimum QLT heat treatment parameter in terms of temperature are determined as Q:860℃,L:700℃,and T:600℃,resulting in the better combined properties with yield strength of 756MPa,tensile strength of 820MPa,tensile elongation of 16.76%and yield ratio of 0.923.

关键词： high strength low alloy(HSLA)steel QLT heat treatment tempering microstructures mechanical properties

具有渐变式折射率分布布拉格反射层的发光二极管

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

固体电子学研究与进展 2013年第4期33卷 355-358页

作者：陈凯轩厦门乾照光电股份有限公司福建厦门361101

对具有渐变式折射率分布布拉格反射层(GRIN-DBR)的发光二极管进行了研究。研究发现,在传统分布布拉格反射层(C-DBR)的AlAs/Al0.45Ga0.55As的界面处插入5nm厚的折射率渐变层,可以使DBR的反射带宽从82nm增加到103nm。在20mA注入电流下,具... 详细信息

对具有渐变式折射率分布布拉格反射层(GRIN-DBR)的发光二极管进行了研究。研究发现,在传统分布布拉格反射层(C-DBR)的AlAs/Al0.45Ga0.55As的界面处插入5nm厚的折射率渐变层,可以使DBR的反射带宽从82nm增加到103nm。在20mA注入电流下,具有GRIN-DBR的发光二极管与具有C-DBR的发光二极管的正向电压没有明显区别,而其光通量比具有C-DBR的发光二极管高8%。

关键词：渐变式折射率分布布拉格反射层发光二极管金属有机化学气相外延