检索结果-南通市图书馆

Interfacial Microstructure and Properties of Ti(C, N)/Ni Bonded by Transient Liquid-phase Diffusion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2009年第3期24卷 432-439页

作者：周世权熊惟皓 School of Mechanical science and Engineering Huazhong University of Science and Technology Department of Mechanical Engineering University of Waterloo School of Materials science and Engineering Huazhong University of Science and Technology

Effects of the main process parameters（temperature and time） on microstructure and properties of Ti（C, N）/Ni interface bonded by （Cu＋Nb） interlayer in a vacuum diffusion bonding device were investigated. The interfacial microstructures consisted initially of Ni3.b metallic compound and eutectic of Ni3.b ＋ CuNiss, and finally transformed to （Ti, Nb）（C, N）＋Ni3.b near Ti （C, N） and NiCuss ＋ Ni3.b near Ni when diffusion bonding temperature was 1 52.0}1 573.K. It was clear that Cu was a constituent in the transient liquid phase （TLP） into which Ni was dissolved by forming Cu-Ni transition liquid. Nb was dissolved in Cu-Ni transition liquid rapidly. Ti （C, N） conld be wetted by resultant Ni-Nb-Cu transient liquid phase which was followed by a little （Ti, Nb）（C, N） solid solution formed at interface. This increased the interface combining capability. Ultimately the interface shear strength was able to reach 140 MPa. The theoretle analysis and experimental results show that the growth of interfacial reaction layer Ni3.b accords with parabola law, and the activation energy of diffusion reaction is 115.0±0.5 kJ/mol, while the diffusion reaction speed constant is 12.53.mm/s^1/2.

关键词： vacuum diffusion bonding transient liquid phase (TLP) diffusion bonding interlayer activation energy

Interlayer exciton dynamics of transition metal dichalcogenide heterostructures under electric fields

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4555-4572页

作者： Jian Tang Yue Zheng Ke Jiang Qi You Zhentian Yin Zihao Xie henan Li Cheng Han Xiaoxian Zhang Yumeng Shi International Collaborative Laboratory of 2. Materials for Optoelectronics science and Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China college of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Luminescence and Optical Information Ministry of EducationInstitute of Optoelectronic TechnologyBeijing Jiaotong UniversityBeijing 100044China

Stacking single layers of atoms on top of each other provides a fundamental way to achieve novel material systems and engineer their physical properties,which offers opportunities for exploring fundamental physics and realizing next-generation optoelectronic *** the two-dimensional(2.)-stacked systems,transition metal dichalcogenide(TMDC)heterostructures are particularly attractive because they host tightly-bonded interlayer excitons which possess various novel and appealing *** interlayer excitons have drawn significant research attention and hold high potential for the application in unique optoelectronic devices,such as polarization-and wavelength-tunable single photon emitters,valley Hall transistors,and possible high-temperature *** development of these devices requires a comprehensive understanding of the fundamental properties of these interlayer excitons and the impact of electric fields on their *** this review,we summarize the recent advances on the understanding of interlayer exciton dynamics under electric fields in TMDC *** put emphasis on the electrical modulation of interlayer excitons’emission,the valley Hall transport of charge carriers after the separation of interlayer excitons by an electric field,and the correlation physics of interlayer excitons and charges under electrical doping and *** and perspectives are finally discussed for the application of TMDC heterostructures in future optoelectronics.

关键词： interlayer exciton transition metal dichalcogenide(TMDC)heterostructures circular polarization valley Hall effect strong coupling

Detection of Prorocentrum donghaiense using sandwich hybridization integrated with nuclease protection assay

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

Acta Oceanologica Sinica 2009年第2期28卷 121-126页

作者： CHEN Jie ZHEN Yu MI Tiezhu YU Zhigang college of Marine life {2. Ocean University of China Qingdao 266003 China college of Environmental science and Engineering Ocean University of China Qingdao 266100 China college of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

Prorocentrum donghaiense is an important harmful algae bloom （HAB） causing creature in china＇s seas, and the conventional visual detection can not cope with long-term monitoring and highthroughput sampling projects. An assay for P. donghaiense with sandwich hybridization integrated with nuclease protection assay （NPA-SH） was established. Tests with mixed samples and spiked field ones confirmed its good specificity and sensitivity. The cell number of P. donghaiense correlated well with the optical density, and the regression equation is y=4× 10^- 6x＋ 0.694 9, in which x is the cell number, and y is the optical density, with r2.0.953.5. These results show that the NPA-SH method has good feasibility in the detection of P. donghaiense. Results of NPA-SH and microscopy are excellent for each sample. The NPA-SH method was a simple way in quantitative detection of P. donghaiense, and the whole process could be finished in about six hours, which provided a new approach in high-throughput sampling and long-term monitoring of P. donghaiense.

关键词： Prorocentrum donghaiense ribosomal RNA S1 enzyme sandwich hybridization integrated with nuclease protection assay (NPA-SH)

Weighted composition operators between μ-Bloch spaces on the unit ball

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2005年第10期48卷 1349-1368页

作者： ZHANG Xuejun~1 & XIAO Jianbin~2.1. college of Mathematics and Computer science,Hunan Normal {2.,Changsha 410006,{3.(email:xuejunttt@2.3. net) 2. The School of science,Hangzhou Dianzi {2.,Hangzhou 3.003.,{3. college of Mathematics and Computer science Hunan Normal University Changsha China The School of science Hangzhou Dianzi University Hangzhou China

In this paper,necessary and sufficient conditions are given for the weighted composition operator T_(ψ,ψ) to be bounded or compact from the space β_μ to β_ν (or β_(μ,0) to β_(ν,0) ) on the unit ball of C^***... 详细信息

关键词： μ-Bloch space, weighted composition operator, boundedness, compactness.

Dry Friction Characteristics of Ti-6Al-4V Alloy under High Sliding Velocity

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2007年第4期22卷 582-585页

作者：邱明 School of Mechatronic Engineering Henan University of Science and Technology Theory of Lubrication and Bearing Institute Xi'an Jiaotong UniversityXi'an 710049China

Tribological behaviours of Ti-6Al-4V alloy pins sliding against GCr15 steel discs over a range of contact pressures （0.3.-1.3. MPa） and sliding velocities （3.-70 m/s） were investigated using a pin-on-disc tribometer under unlubricated conditions. The wear mechanisms and the wear transition were analyzed based on examinations of worn surfaces using SEM, EDS and XRD. When the velocity increases, the friction coefficient and the wear rate of the Ti-6Al-4V alloy show typical transition features, namely, the critical values of sliding velocities for 0.3. and 0.67 MPa are 60 and 40 m/s, respectively. The experimental results reveal that the tribological behaviours of Ti-6Al-4V alloys are controlled by the thermal-mechanical effects, which connects with the friction heat and hard particles of the pairs. A tribolayer containing mainly Ti oxides and V oxides is formed on the worn surface of Ti-6Al-4V alloy.

关键词： Ti alloy dry sliding friction behavior contact temperature wear mechanism

CMC surfaces in the hyperbolic 3.space

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第7期43卷 547-550页

作者： YU Zuhuan 1, 2.and LI Zhenqi 1, 3.1. Institute of Mathematics, Fudan university, Shanghai 2.043., china 2. Department of Mathematics,Sichuan Union university, Chengdu 610064, china 3. Department of Mathematics, Nanchang university, Nanchang 3. nstitute of Mathemalics Fudan University Shanghai China Department of Mathematics Sichuan Union University Chengdu China Department of Mathematics Nanchang University Nanchang China

CMC-H surfaces satisfying H≥1 are studied. It is proved that these surfaces possess a natural representation which is a generalization of the Bryant’s result.

关键词： hyperbolic space CMC surface Weierstrass representation.

New fossil elaterid (Coleoptera: Polyphaga: Elateridae) from Yixian Formation of western Liaoning, china

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2007年第10期17卷 1244-1249页

作者： Chang Huali, Ren Dong and Shih Chungkun(college of life {2., Capital Normal {3., Beijing 10003., china) college of life {2. Capital Normal University Beijing 100037 China

A new species of the elaterid genus Cryptocoelus Dolin and Nel, 2.02.from the Late Jurassic to Early Cretaceous Yixian Formation in the western Liaoning, china is described. Diagnosis of the genus is revised, and the systematic position of the genus is briefly discussed. Because the elaterids originated in the Early to Mid-Jurassic, this new material from the Late Jurassic-Early Cretaceous will enhance our understanding of the transition between ancient elaterids and extant ones, bridge the gap of cryptic relationships between the Mesozoic cupedids and elaterids, and expand our knowledge of their evolutionary history.

关键词： Elateridae new species Yixian Formation china.

Expression and Identification of Mutated Osteoprotegerin in Culture Cells and Larvae of Silkworm

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第5期36卷 331-335页

作者： Hai-Long XIAO, Yong-Feng JIN, and Yao-Zhou ZHANG1* Institute of Biochemistry, college of life {2.s, Zhejiang {3., Hangzhou 3.002., china college of life {2.s, Zhejiang {3. of {2. & Technology, Hangzhou 3.0018, china college of life {2.s Zhejiang University of Science & TechnologyHangzhou 310018China Institute of Biochemistry College of Life SciencesZhejiang UniversityHangzhou 310029China

The mutated osteoprotegerin (OPG-3.2. gene was inserted into the baculovirus transfer vector pBacPAK8, and the recombinant plasmid was co-transfected with linearized Bm-BacPAK6 virus DNA into BmN cells, then homologous recombination occurred inside the cells. The recombinant virus BmNPV-OPG- 3.2.was screened and identified by Southern blotting. The recombinant human OPG-3.2.was expressed in cultured cells and the larvae of silkworm by inoculation of recombinant virus. The expression products were run on the SDS-PAGE and their immunoreactivities were determined by Western blotting. It was found that a 42.kD recombinant protein was expressed in BmN cells and a 46 kD one in larvae respectively. The bioactivi- ties of the recombinant proteins were determined by hypocalcemic effect assay in the mice. The results showed that the recombinant proteins had a significant hypocalcemic effect on mice sera.

关键词： OPG-3.2 silkworm baculovirus expression system hypocalcemic effect

Analysis on cohesive crack opening displacement considering the strain softening effect

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3.1. Mechanics Department, Shandong university of Technology, Zibo 2.5049, {2. 2. Civil Engineering Department, Dalian university of Technology, Dalian 11602., {2. 3. Mathematics Department, Ocean university of {2., Qingdao 2.6071, {2. Mechanics Department Shandong University of Technology Zibo China Civil Engineering Department Dalian University of Technology Dalian China Mathematics Department Ocean University of China Qingdao China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.