检索结果-南通市图书馆

Atmospheric and Oceanic Science Letters 2017年第1期10卷 89-95页

作者： CHEN guang-Hua wang xu Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of Science

The characteristics of quasi-biweekly oscillation（QBWO） over the South China Sea during early summer are *** results demonstrate that QBWO convection and the meridional wind anomaly exhibit local variation,while the zonal wind anomaly displays zonal ***,emergence of the zonal wind anomaly precedes the enhancement of QBWO convection,suggesting the zonally propagating zonal wind anomaly may play a key role in initiating the development of QBWO *** of the convergence of moisture flux and divergence tendency indicate that QBWO convection is primarily modulated by eddy *** the contributing factors in the divergence tendency,the β effect associated with the zonally-propagating zonal wind anomaly makes an appropriate phase difference with the eddy divergence,which can contribute to the convergence tendency in the initial stage of *** a result,QBWO convection and the meridional wind anomaly are enhanced,thus facilitating the initial development of QBWO convection over the SCS during early summer.

关键词： Westward-propagating zonal wind quasi-biweekly oscillation South China Sea early summer

Surface and interface analysis of HAP/TiO2 composite films on Ti6Al4V

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第z1期14卷 193-198页

作者： SU Bing ZHANG Weng-guang YU xu-dong wang Cheng-tao School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China 1st Department Artillery Academy of PLA of China Hefei 230031 China School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.

关键词： titanium dioxide hydroxyapatite composite film spin-coating technique

Channel effect of the modified powdery mixture of ammonium nitrate and fuel oil

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

International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 519-525页

作者： Chun-ping Wu Lian-sheng Liu xu-guang wang Yong Liu Yin-jun wang School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Beijing General Research Institute of Mining and Metallurgy Beijing 100044 China College of Resource and Environmental Engineering Jiangxi University of Science and Technology Ganzhou 341000 China Ordnance Industry Planning Project Institute of China Beijing 100053 China

The modified powdery mixture of ammonium nitrate and fuel oil （MPANFO） is a new breed of industrial explosives developed years ago in China. As one of the important properties of an industrial explosive, the channel effect of MPANFO was reported in this paper. A series of experiments were conducted to determine the channel effect of MPANFO. The blasthole diameter range was estimated to avoid the channel effect of MPANFO. Three empirical formulae for predicting the detonation length of MPANFO were provided in terms of the channel effect. Experiments and theoretical analysis indicate that the channel effect of MPANFO is very serious. The reason why the channel effect of MPANFO is worse than that of other industrial explosives is explained at a theoretical level. In addition, some properties of MPANFO, such as sympathetic distance, detonation velocity and brisance, are determined.

关键词： energetic materials explosives detonation channel effect

Expression Characterization and Preparation of Human Amyloid Precursor Protein in Escherichia coli

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第1期25卷 64-68页

作者： xu guang-wei wang Jia-peng HUANG xue-mei ZHANG Ying-jiu Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education Jilin University Changehun 130021 P R. China

To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investigated the expression characterization and preparation of the three intact isoforms APP770, APP751, and APP695 in E. coll. The results show that these expressed APPs existed both in hydrophilic cytoplasm region as inclusion bodies and hydrophobic membrane region as membrane-bound state in E. coll. APPs in inclusion bodies were purified on an NTA-Ni^2＋ agarose column after dissolving in the urea buffer and APPs in membrane-bound state were obtained by ultracentrifugation. The activity analysis indicates that APP770 and APP751 exhibited strong trypsin-inhibitory activity like the natural ones. These results indicate that E. coli cells can be used as host cells for the expression of human integral membrane protein like APP in either soluble or membrane-bound state unless the interest protein undergone post-translational modification is required.

关键词： Amyloid precursor protein Expression characterization Preparation Membrane Inclusion body

Dynamics of an Ultracold Bose Gas in Funnel-Shaped Potential

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第9期52卷 431-434页

作者： YAN Li xu guang-Yuan wang Yong-Jun LIU Xian-Feng HAN Jiu-Rong Department of Physics Yangzhou University Yangzhou 225002 China

In this paper we develop a variational theory to study the dynamic properties of ultracold Bose gas ina funnel external *** obtain one-dimensional nonlinear equation which describes the dynamics of transversetight confined bosonic gas from three-dimension to one-dimension,and find one-dimensional s-wave scattering lengthwhich depends on the shape of transverse confining *** the funnel trapping potential is strong enough at zerotemperature,all transverse excitations are *** find the dynamic equation which describes the Tonks-Girardeaugas and present a qualitative analysis of the experimental accessibility of the Tonks-Girardeau gas with funnel-trappedalkalic atoms.

关键词： funnel potential variational method ultracold Bose gas Tonks Girardeau region

Correlation between grain size,mechanical properties and deformed microstructure of Fe-20Mn-6Al-0.6C-0.15Si low-density steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2025年第1期32卷 282-292页

作者： Qi Zhang guang-hui Chen Zheng-liang xue Zheng-kun Chen guang xu State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Red Eagle Novel Refractory Materials Research Institute Zhejiang Red Eagle Group Co.Ltd.Huzhou313000ZhejiangChina

The effects of austenite grain size on the deformed microstructure and mechanical properties of an Fe-20Mn-6Al-0.6C-0.15Si(wt.%)low-density steel were *** microstructure of the experimental steel after solution treatment was single austenitic *** austenite grain size increased with solution temperature and time.A model was established to show the relationship between temperature,time and austenite grain size for the experimental *** addition,as the solution temperature increased,the strength decreased,while the elongation first increased and then *** decrease in elongation after solution treatment at 1100℃ for 90 min is contributed to the over-coarse austenite ***,after solution treatment at 900℃ for 90 min,the strength-elongation product reached the highest value of 44.4 GPa%.As the austenite grain size increased,the intensity of//tensile direction fiber *** was accompanied by a decrease in dislocation density,resulting in a lower fraction of low-angle grain boundaries and a lower work hardening ***,the austenite grain size has a critical influence on the mechanical properties of the low-density *** grains lead to a lower yield strength due to the Hall-Petch effect and a lower tensile strength because of lower dislocation strengthening.

关键词： Austenitic low-density steel Solution treatment Grain size Mechanical property Deformed microstructure

Concurrent Design Study of the Petroleum Equipment CAD System

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

厦门大学学报（自然科学版） 2002年第S1期41卷 269-270页

作者： CHEN Yong-guang, CHEN xu, wang Jiang (Mechanical Engineering Institute, Chongqing University,Chongqing 4000 44, China)

Military petroleum equipment, as the special device a nd tool for petroleum storage, transportation, filling, chemical analysis, detec tion and maintenance for the army, is an important means and basis of petroleum indemnificatory. To adapt to modern war in high-tech conditions, the petroleum equipment have to develop towards higher reliability, adaptability, maneuverabil ity, standardization, container and cell type with versatile multi-functions. As a new design theory and design process, concurrent engineering may prod uce remarkable benefit when applying to product development. With the aid of the state-of-the-art modeling and simulation technology, it foresees the future or even the whole life cycle of the products designed. Based on wide statistics and survey, the product design period is reduced by 1/2～1/3 with concurrent des i gn process. The application of concurrent design process in new petroleum equi pment development shall greatly accelerate the petroleum equipment updating an d promote their indemnificatory.

关键词： petroleum equipment concurrent engineering CAD

Electroluminescence from the InGaN/GaN Superlattices Interlayer of Yellow LEDs with Large V-Pits Grown on Si(111)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第5期35卷 115-118页

作者： Xi-xia Tao Chun-lan Mo Jun-lin Liu Jian-li Zhang Xiao-lan wang Xiao-ming Wu Long-quan xu Jie Ding guang-xu wang Feng-yi Jiang National Institute of LED on Silicon Substrate Nanchang University Nanchang 330047 Nanchang Yellow Green Lighting Company Limited Nanchang 330047

A blue emission originated from In GaN/GaN superlattice（SL） interlayer is observed in the yellow LEDs with V-pits embedded in the quantum wells（QWs）, revealing that sufficient holes have penetrated through the QWs into SLs far away from the p-type layer. In the V-pits embedded LEDs, hole transport has two paths： via the flat c-plane region or via the sidewalls of V-pits. It is proved that the holes in SLs are injected from the sidewalls of V-pits, and the transportation process is significantly affected by working temperature, current density, and the size of V-pits. Four motion possibilities are discussed when the holes flow via the sidewalls. All these may contribute to a better understanding of hole transport and device design.

关键词： In GaN

Effect of Green Quantum Well Number on Properties of Green GaN-Based Light-Emitting Diodes

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第8期35卷 79-82页

作者： Zhi-Hui wang Xiao-Lan wang Jun-Lin Liu Jian-Li Zhang Chun-Lan Mo Chang-Da Zheng Xiao-Ming Wu guang-xu wang Feng-Yi Jiang National Engineering Technology Research Center for LED on Si Substrate Nanchang University

In GaN-based green light-emitting diodes（LEDs） with different green quantum well numbers grown on Si（111）substrates by metal organic chemical vapor deposition are investigated. It is observed that V-shaped pits appear in the AFM images with the green quantum well number increasing from 5 to 9, and results in larger reverse-bias leakage current. Meanwhile, in the case of the sample with the number from 5 to 7 then to 9, the external quantum efficiency increases firstly, and then decreases. These phenomena may be related to the size of V-shaped pits in the active area and the distribution of electrons and holes in the active area caused by V-shaped pits. The optimal number of green quantum wells is determined to be 7.

关键词： GaN Effect of Green Quantum Well Number on Properties of Green GaN-Based Light-Emitting Diodes

Effect of Mg-Preflow for p-AlGaN Electron Blocking Layer on the Electroluminescence of Green LEDs with V-Shaped Pits

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第2期35卷 88-92页

作者： Ai-Xing Li Chun-Lan Mo Jian-Li Zhang Xiao-Lan wang Xiao-Ming Wn guang-xu wang Jun-Lin Liu Feng-Yi Jiang National Institute of LED on Silicon Substrate Nanchang University

In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in the EBL after Mg-preflow treatment,effectively alleviating the commonly observed efficiency collapse and electrons overflowing at cryogenic ***,unexpected decline in quantum efficiency is observed after Mg-preflow treatment at room *** conclusions are drawn such that the efficiency decline is probably the result of different emission *** Mg doping concentration in the EBL after Mg-preflow treatment will make it easier for a hole to be injected into multiple quantum wells with emission closer to pGaN side through the（8-plane rather than the V-shape pits,which is not favorable to luminous efficiency due to the preferred occurrence of accumulated strain relaxation and structural defects in upper QWs closer to *** this framework,apparently disparate experimental observations regarding electroluminescence properties,in this work,are well reconciled.

关键词： GaN EBL Effect of Mg-Preflow for p-AlGaN Electron Blocking Layer on the Electroluminescence of Green LEDs with V-Shaped Pits