Results 31 to 40 of about 23,320 (232)

Crystallization Engineering of GaAs/Sb2S3 Core‐Shell Nanowires for Gain Manipulation of Photodetectors

open access: yesRare Metals, EarlyView.
ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao   +11 more
wiley   +1 more source

Preparation and Characterization of BN Coating on SiC Fibers by Carbothermal Reduction [PDF]

open access: yes, 2016
本论文以硼酸三甲酯(trimethylborate—TMB)蒸气为硼源、NH3气为氮源,采用碳热还原氮化法在SiC纤维表面制备BN涂层。首先,SiC纤维与Cl2气反应表面生成碳化物衍生碳(carbide-derivedcarbon—CDC)层,然后,CDC层与TMB蒸气及NH3气在1300C发生碳热还原氮化反应,生成BN涂层。采用FT-IR、XPS、XRD、AES、SEM、TEM、电阻率测试、单丝拉伸试验等系统地研究了所得BN涂层的组成、结构和性能。研究发现 ...
袁梦娇
core  

Engineering 2D Materials for High‐Current‐Density Electrocatalytic Water Splitting

open access: yesRare Metals, EarlyView.
ABSTRACT Water electrolysis is a key method for sustainable hydrogen production, using water as an abundant resource. However, efficient and stable operation at high current densities remains challenging due to energy losses, catalyst degradation, and limited ion–electron transport.
Tianqi Guan   +8 more
wiley   +1 more source

微课在脑卒中教学中的应用

open access: yesZhongguo shiyan zhenduanxue, 2018
康复医学教学是理论与实践并重的教学模式,不同于纯理论教学课程,对同学的实践动手能力和模仿能力要求较高。目前以PPT为主的课堂教学对理论教学能够完成教学目的和要求,而对实践性较高的康复实践显然不能满足,PBL教学能够调动学员的积极性,主动参与到教学当中,但对于课时相对紧凑的课种来说,真正实施起来较为困难[1,2]。微课融合了视频等要素,不但能够课堂展示 ...
康治臣   +7 more
doaj  

In-situ Raman Observations of PLZT Ferroelectric Ceramics under Stress Fields [PDF]

open access: yes, 2015
在外场作用下铁电陶瓷材料的畴变会造成材料微结构的变形,最终会引发材料的性能退化、材料失效。因此了解铁电材料的破坏机理,研究外场作用下铁电材料的畴变规律,对提高铁电材料的使用价值具有指导性的意义。为探讨力场作用下铁电陶瓷的畴变规律,本论文开展了外力场作用下铁电陶瓷拉曼光谱变化的原位观测研究。论文工作包括:利用固相反应法合成了组成为Pb0.9La0.1(Zr0.52Ti0.48)0.975O3且晶粒尺寸(约5m)适于原位拉曼光谱观测的铁电多晶陶瓷;对合成出的PLZT铁电陶瓷进行化学组分 ...
梁丽苹
core  

Gravity‐Driven Inclination Sensor Based on Liquid Metal Interface Migration in Anisotropic Microchannels for Information Transmission and Continuous Surface Topography Scanning

open access: yesRare Metals, EarlyView.
ABSTRACT With the continuous advancement of materials science and technology, the rare metal gallium has increasingly emerged as a promising alternative to the toxic metal mercury. Although existing research has predominantly focused on the high electrical conductivity and excellent deformability of liquid metal (LM), its intrinsic fluidic property ...
Feifan Guo   +6 more
wiley   +1 more source

材料力学性能不均匀模式对对接接头结构性能分析的影响

open access: yesJianzhu Gangjiegou Jinzhan, 2017
经历不均匀热过程影响的对接焊接接头,呈现不均匀力学性能。在对对接焊接接头疲劳等分析过程中,应考虑不均匀力学性能。根据对接焊接接头分区和力学性能分布,提出了3种对接焊接接头不均匀力学性能分布模式:二区模式、五区模式和连续化模式。采用有限元方法分析材料力学性能不均匀模式对对接焊接结构性能分析的影响。采用3种模式结合已有试验数据,建立了不同精细化程度的有限元模型并进行有限元分析。研究结果表明:分布模式对结果会产生很大的影响,模式越精细,屈服荷载、极限荷载和屈服位移、极限位移就越小 ...
甘结良, 彭洋, 董军
doaj  

Investigation of Microstructure, Mechanical Properties and Irradiation Behaviors of Nuclear Application Steels [PDF]

open access: yes, 2015
在核能领域应用的关键材料的服役条件非常苛刻,需要在辐照、高温、腐蚀、受应力、热循环等极端条件下长期稳定工作,并按照可预期的方式老化、失效。堆内构件的性能与特性决定了核能可以达到的安全水平。中国从美国西屋公司引进、吸收与消化AP1000核电技术,以形成具有自主知识产权的核电技术,并在此过程中着重对一系列核能关键用材料进行了相关研发。本论文以国产SA-182F304钢、304SS钢、CNST1钢、CNST2钢和CNSS3钢为研究对象,对候选钢的微观结构、微观化学、力学行为和抗辐照性能进行了详细研究 ...
陈芙梁
core  

A Micro‐Nano Flower‐Like Na3V2(PO4)3@C Constructed by Polar‐Driven H‐Bond Engineering Toward High‐Rate Sodium Storage

open access: yesRare Metals, EarlyView.
ABSTRACT The polyanionic compound Na3V2(PO4)3 (NVP) has emerged as a competitive cathode material for sodium‐ion batteries (SIBs), owing to its high‐voltage redox activity (3.4 V vs. the Na+/Na reference couple) and NASICON‐type framework that enables superior ionic conductivity.
Xiaolei Wu   +5 more
wiley   +1 more source

双层球面网壳失效机理的多指标评价体系(英文)

open access: yesJianzhu Gangjiegou Jinzhan, 2013
单层球面和柱面网壳结构的承载能力已有不少研究,但双层球面网壳的力学特性和失效机理的研究很少涉及。基于此,系统地研究了4种不同矢跨比双层凯威特球面网壳的失效机理和破坏过程,考察了多个力学指标来评估网壳的力学性能,如变形能力、总应变能、总弹/塑性应变能和屈服杆件数等。捕捉了4种矢跨比网壳的杆件失效过程和失效机理的差异。计算结论可为双层球面网壳结构的设计提供参考与借鉴。
李会军, 王正中
doaj  

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