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Microstructure and Mechanical Properties of Cross-rolled Ti_(50)Ni_(47)Fe_3 Shape Memory Alloy

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Chinese Journal of Aeronautics 2006年第B12期19卷 224-227页

作者： zhao li-xiao liU Fu-shun XU Hui-bin School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

The microstructures, the phase transformation characteristics, and the mechanical properties of the Ti50Ni47Fe3 alloy in as-forged and as-cross-rolled states were investigated. It is found that, after cross-rolling, the phase transformation temperature （Ms） of the alloy decreases drastically and the grains get refined. Moreover, its yield strength and fracture strength after cross-rolling hit 540 MPa and 687 MPa respectively, up by about 200 MPa over those in as-forged state.

关键词： Ti50Ni47Fe3 shape memory alloy cross-rolled mechanical properties

A new free recoverable and reusable mono-alkaloid-type ligand and its use in preparation of ethyl(2R,3S)-2,3-dihydroxy-3-phenylpropionate

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Chinese Chemical Letters 2009年第7期20卷 763-766页

作者： Qiao Feng Wang Hui Chen Yan zhao xiao Ye li Sheng Yong Zhang Research Center of Chirotechnology Fourth Military Medical University Xi'an 710032 PR China

A new free recoverable and reusable mono-alkaloid-type ligand has been synthesized by a simple method. With highly polar groups, the ligand can be recycled and reused eight times to prepare ethyl （2R,3S）-2,3-dihydroxy-3-phenylpropionate with high yield and ee via asymmetric dihydroxylation （AD） reaction. C 2009 Sheng Yong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Cinchona alkaloid Recoverable and reusable ligand Ethyl (2R,3S)-2,3-dihydroxy-3-phenylpropionate

Evaluation on cutting performance of novel PDC cutter for pipe jacking machine

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Underground Space 2024年第1期14卷 34-52页

作者： Long-Chuan Deng Yi-Xiang Yuan xiao-zhao li Qian-Wei Zhuang Chi Zhang Yi-Wei Chen School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu 210023China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200232China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

It is inevitable to cut reinforced concrete(RC)appeared in cross passage of city metro by cutting tools when constructing in densely populated *** previous cutters employed to cut RC are insufficient and easily damaged,so a new polycrystalline diamond compact(PDC)cutter is used to solve this *** on the theoretical analysis of cutting mechanism,both circular and tapered PDC cutters with cutting edge angle of 90and negative front rack angle of 10are used to cut *** peeling and breaking patterns of cutting concrete are proposed,the nodular and grainy chips are the preferred modes in cutting steel *** LS-DYNA is employed to investigate the cutting performance in *** simulation results show that the average and peak cutting forces increase with the growth of penetration depth,cutting speed,and roundness,and subsequently the recommended penetration depth less than 1.2 mm is obtained to cut RC due to the existence of steel ***,the linear cutting platform is adopted to investigate the force ability and damage state of PDC *** is concluded that the cutting force increases abruptly and fluctuates heavily when cutting the coarse *** patterns occurred in both numerical and experimental results are generally ***,the steel bar is pulled out and the PDC cutter is damaged at the penetration depth of 0.8 mm,while a good cut occurs at the penetration depth of 0.3 *** tapered PDC cutter with a relatively low cutting force is prone to be broken compared with circular PDC *** is suggested that the circular PDC cutter at the penetration depth of 0.3 mm should be used to cut RC in practical engineering.

关键词： PDC cutter RC Pipe jacking machine linear cutting tests Damage and wear LS-DYNA

Numerical analysis of elastic coated solids in line contact

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Journal of Central South University 2015年第7期22卷 2470-2481页

作者：王廷剑王黎钦古乐赵小力 School of Mechatronics Engineering Harbin Institute of Technology

A line contact model of elastic coated solids is presented based on the influence coefficients(ICs) of surface displacement and stresses of coating-substrate system and the traditional contact model. The ICs of displacement and stresses are obtained from their corresponding frequency response functions(FRF) by using a conversion method based on fast Fourier transformation(FFT). The contact pressure and the stress field in the subsurface are obtained by employing conjugate gradient method(CGM) and discrete convolution fast Fourier transformation(DC-FFT). Comparison of the contact pressure and subsurface stresses obtained by the numerical method with the exact analytical solutions for Hertz contact is conducted, and the results show that the numerical solution has a very high accuracy and verify the validity of the contact model. The effect of the stiffness and thickness of coatings is further numerically studied. The result shows that the effects on contact pressure and contact width are opposite for hard and soft coatings and are intensified with the increase of coating thickness; the locations of crack initiation and propagation are different for soft and hard coatings; the risk of cracks and delaminations of coatings can be brought down by improving the lubrication condition or optimizing the non-dimensional parameter h/bh. This research offers a tool to numerically analyze the problem of elastic coated solids in line contact and make the blindness and randomness of trial-type coating design less.

关键词： coating-substrate system contact pressure stress field frequency response function influence coefficient

Effects of RNA interference-induced tryptase down-regulation in P815 cells on IL-6 and TNF-α release of endothelial cells

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第8期9卷 656-661页

作者： Yi-feng JIANG Feng-di zhao xiao-bo li Yan-xia NING Xiu-ling ZHI Rui-zhe QIAN lian-hua YIN Department of Physiology and Pathophysiology Shanghai Medical College Fudan University Shanghai 200032 China

Objective： To explore the effects of down-regulated tryptase expression in mast cells on the synthesis and release of interleukin-6 （IL-6） and tumor necrosis factor-alpha （TNF-α） of vascular endothelial cells. Methods： Tryptase-siRNA （small-interfering RNA） vector was constructed to inhibit tryptase expression in P815 cells. The medium of P815 cells treated by the tryptase-siRNA （RNAi-P815 group） or pure vector （P815 group） was collected and used to culture bEnd.3 cells. The messenger RNAs （mRNAs） of IL-6 and TNF-α in bEnd.3 cells and their protein levels in the medium were measured by reverse transcription polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （EliSA）, respectively. Results： IL-6 and TNF-α mRNAs in bEnd.3 cells cultured in RNAi-P815-conditioned medium decreased significantly compared to those in P815-conditioned medium. Consistently, lL-6 and TNF-α protein levels in the medium of bEnd.3 of RNAi-P815 group were lower than those of P815 group. Conclusion： Reduced tryptase expression significantly inhibited the synthesis and release of IL-6 and TNF-α in vascular endothelial cells. RNA interference targeting tryptase expression may be a new anti-inflammatory strategy for vascular diseases.

关键词： Tryptase RNA interference lnterleukin-6 (IL-6) Tumor necrosis factor-alpha (TNF-α) Endothelial cells

Differences in microstructure and properties between selective laser melting and traditional manufacturing for fabrication of metal parts： A review

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Frontiers of Mechanical Engineering 2015年第2期10卷 111-125页

作者： Bo SONG xiao zhao Shuai li Changjun HAN Qingsong WEI Shifeng WEN Jie liU Yusheng SHI State Key Laboratory of Materials Processing and Die & MouldTechnology Huazhong University of Science and Technology Wuhan430074 China

Selective laser melting （SLM）, as one of the additive manufacturing technologies, is widely investigated to fabricate metal parts. In SLM, parts are manufactured directly from powders in a layer-by-layer fashion; SLM also provides several advantages, such as production of complex parts with high three-dimensional accuracy, compared with other additive manufacturing technologies. Therefore, SLM can be applied in aeronautics, astronautics, medicine, and die and mould industry. However, this technique differs from traditional methods, such as casting and forging; for instance, the former greatly differs in terms of microstructure and properties of products. This paper summarizes relevant studies on metal material fabrication through SLM. Based on a work completed in Huazhong Univ. Sci Tech., Rapid Manuf. Center （HUST-RMC） and compared with characteristics described in other reported studies, microstructure, properties, dimensional accuracy, and application of SLM are presented.

关键词： selective laser melting microstructure performance application

Two cases of exudative retina detachment and uveitis following H1N1 influenza vaccination

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Chinese Medical Journal 2011年第22期124卷 3838-3840页

作者： TAO Yong CHANG li-bing zhao Min li xiao-xin Department of Ophthalmology Peking University People＇s Hospital Key Laboratory of Vision Loss and Restoration Ministry of Education Beijing 100044 China

Uveitis was a rare adverse event of vaccination. We met two cases of acute uveitis with exudative retinal detachment following vaccination of H1 N1 influenza. Case 1 was a 10-year-old boy who was admitted for bilateral blurred vision at 10 days after vaccination of H1N1 influenza. Vitreous opacity was obvious in both eyes. Broad exudative retinal detachment was observed in the right eye. Case 2 was a 47-year-old female who suffered from an acute high fever at 2 days after the vaccination of H1 N1 influenza. Later, she encountered bilateral headache and decreasing vision. In both eyes, mutton fat keratic precipitates, positive Tyndall phenomenon, congestion of optic disc and exudative retinal detachment were observed.

关键词： retinal detachment uveitis vaccine H1N1 influenza

Spatial changes of wind erosion-caused landscapes and their relation with wind field in China

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Journal of Geographical Sciences 2002年第2期12卷 30-39页

作者： Zhang Guo-ping liu Ji-yuan Zhang Zeng-xiang zhao xiao-li Zhou Quan-bin CAS Institute of Remote Sensing Applications Beijing China (GRID:grid.9227.e) (ISNI:***) CAS Institute of Geographic Sciences and Natural Resources Research Beijing China (GRID:grid.9227.e) (ISNI:***)

Based on the results of remote sensing investigations of the landscapes of 1995 and 2000, the national distribution of sandy desertified land and its interaction with other landscapes are classified, and five zonal types are distinguished. The data of nationally distributed 400 meteorological stations of 1999 are processed. With the GIS method, the data are spatially interpolated, and the national database of wind field concerned with wind erosion is established. In arid and semi-arid areas of China, the intensity of wind field is one of the key factors that controls the development of landscape especially in desert and its adjacent area. Different indexes are set up to describe the intensity of wind field, the method suggested by the wind erosion prediction models of RWEQ is also adopted to express the intensity of wind. The Weibull distribution is used to describe the wind field in China. Based on the analysis of the process of the wind erosion-driven landscape changes, this article proposes and discusses the control measures of wind erosion.

关键词： remote sensing sandy desertification Weibull distribution desertification control in China wind energy

全局与局部判别信息融合的转子故障数据集降维方法研究

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自动化学报 2017年第4期43卷 560-567页

作者：赵孝礼赵荣珍兰州理工大学机电工程学院兰州730050

针对传统的数据降维方法无法兼顾保持全局特征信息与局部判别信息的问题,提出一种核主元分析(Kernel principal component analysis,KPCA)和正交化局部敏感判别分析(Orthogonal locality sensitive discriminant analysis,OLSDA)相结合的转子故障数据集降维方法.该方法首先利用KPCA算法有效降低数据集的相关性、消除冗余属性,由此实现了最大程度地保留原始数据全局非线性信息的作用;然后利用OLSDA算法充分挖掘出数据的局部流形结构信息,达到了提取出具有高判别力低维本质特征的目的.上述方法的特点是通过同时进行的正交化处理可避免局部子空间结构发生失真,采用三维图直观显示出低维结果,以低维特征子集输入最近邻分类器(K-nearest neighbor,KNN)的识别率和聚类分析之类间距Sb、类内距Sw作为衡量降维效果的指标.实验表明该方法能够全面地提取出全局与局部判别信息,使故障分类更清晰,相应地识别准确率得到了明显提升.该研究可为解决高维和非线性机械故障数据集的可视化与分类问题,提供理论参考依据.

关键词：故障诊断数据可视化数据降维核主元分析正交化局部敏感判别分析