检索结果-南通市图书馆

Crystal Plasticity Finite Element Process Modeling for Hydro-forming Micro-tubular Components

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

Chinese Journal of Mechanical Engineering 2011年第1期24卷 78-83页

作者： ZHUANG Weimin wang shiwen BALINT Daniel LIN Jianguo State Key Laboratory of Automotive Dynamic Simulation Jilin University Changchun 130022 China Department of Mechanical Engineering lmperial College London SW7 2AZ UK

Micro-tubes manufactured by hydro-forming techniques have now been widely used in medical and microelectronics applica- tions. One of the difficulties in forming such parts is the control of localized necking in the initial stages of the deformation/forming process. A lack of microstructural information causes conventional macro-mechanics finite element（FE） tools to break down when used to investigate the localized microstructure evolution and necking encountered in micro-forming. An effort has been made to create an integrated crystal plasticity finite element（CPFE） system that enables micro-forming process simulations to be carried out easily, with the important features in forming micro-parts captured by the model. Based on Voronoi tessellation and probability theory, a virtual GRAIN（VGRAIN） system is created for generating grains and grain boundaries for micro-materials. Numerical procedures are devel- oped to link the physical parameters of a material to the control variables in a Gamma distribution. A script interface is developed so that the virtual microstructure can be input to the commercial FE code, ABAQUS, for mesh generation. A simplified plane strain CPFE modeling technique is developed and used to capture localized thinning and failure features for hydro-forming of micro-tubes. Grains within the tube workpiece, their distributions and orientations are generated automatically by using the VGRAIN system. A set of crystal viscoplasticity constitutive equations are implemented in ABAQUS/Explicit by using the user-defined material subroutine, VUMAT. Lo- calized thinning is analyzed for different microstructures and deformation conditions of the material using the CPFE modeling technique. The research results show that locations of thinning in forming micro-tubes can be random, which are related to microstructure and grain orientations of the material. The proposed CPFE technique can be used to predict the locations of thinning in forming micro-tubes.

关键词： micro-mechanics modeling micro-forming hydro-forming

Saliva-based point-of-care testing techniques for COVID-19 detection

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2022年第3期37卷 472-476页

作者： shiwen wang Ying Liu Yang Qiu Qian Dou Yang Han Muhan Huang Ke Hong Bei Yang Xi Zhou Qing Dai CAS Key Laboratory of Nanophotonic Materials and Devices CAS Key Laboratory of Standardization and Measurement for NanotechnologyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing100190China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of SciencesTianjin UniversityTianjin300072China State Key Laboratory of Virology Wuhan Institute of VirologyCenter for Biosafety Mega-ScienceChinese Academy of SciencesWuhan430071China Joint Laboratory of Infectious Diseases and Health Wuhan Institute of Virology&Wuhan Jinyintan HospitalWuhan Jinyintan HospitalWuhan430048China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

Saliva has recently attracted increasing interest for disease diagnosis since it presents a rich pool of biological markers such as proteins,DNA,RNA,hormones,***,saliva collection is convenient and safe,making it a perfect candidate for point-of-care testing(POCT)*** saliva-based POCT devices have been developed for large-scale pandemic screening,self-diagnosis,daily health monitoring.

关键词： diagnosis POCT Saliva

Chemoproteomics reveals the epoxidase enzyme for the biosynthesis of camptothecin in Ophiorrhiza pumila

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第6期66卷 1044-1047页

作者： Tong Zhang Yan wang shiwen Wu Ernuo Tian Chengshuai Yang Zhihua Zhou Xing Yan Pingping wang CAS‐Key Laboratory of Synthetic Biology CAS Center for Excellence in MolecularPlant SciencesChinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China

Camptothecin is one of the most commonly used anticancer drugs worldwide,yet the downstream biosynthetic route from strictosidine to camptothecin has remained unclear for more than half a ***,we searched for proteins involved in camptothecin biosynthesis from the camptothecin-producing plant Ophiorrhiza pumila by chemoproteomics and identified Op CYP716E111.

关键词： camptothecin strict drugs

Mitochondria and left ventricular hypertrophy

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2008年第1期5卷 50-59页

作者： Haiyan Zhu shiwen wang 　 Instititute of Geriatric Cardiology Chinese PLA General HospitalBeijing 100853China

　　Introduction　　Left ventricular hypertrophy (LVH) is one of the vicious organ damages of essential *** contributes a lot to high mortality of essential hypertension due to sudden cardiac death,ventricular arrhythmia and heart *** factors involve in the pathogenesis of hypertension-induced LVH including inherited variants as well as environmental factors.……

关键词： left LVH MELAS Mitochondria and left ventricular hypertrophy mtDNA

Tropical Cyclone Monitoring and Analysis Techniques: A Review

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第2期38卷 351-367页

作者： Chuanhai QIAN Ying LI Yinglong XU Xin wang Zenghai ZHANG Gaozhen NIE Da LIU shiwen ZHANG Institute for Development and Programme Design China Meteorological AdministrationBeijing 100081 Chinese Academy of Meteorological Sciences China Meteorological AdministrationBeijing 100081 National Meteorological Centre China Meteorological AdministrationBeijing 100081 National Satellite Meteorological Centre China Meteorological AdministrationBeijing 100081

Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct ***,detailed monitoring and analysis of TCs has always been an unsolved *** the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and *** new technologies and products gradually emerge to support operations,with improved monitoring *** this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater *** this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.

关键词： tropical cyclone(TC) monitoring and analysis meteorological satellite aircraft reconnaissance

Stability Analysis of a Class of Nonlinear Fractional Differential Systems With Riemann-Liouville Derivative

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1883-1885页

作者： Ruoxun Zhang Shiping Yang shiwen Feng the College of Teacher Education Xingtai University the College of Physics and Information Engineering Hebei Normal University

Dear Editor,This letter investigates the stability ofn-dimensional nonlinear fractional differential systems with Riemann-Liouville derivative. By using the Mittag-Leffer function, Laplace transform and the Gronwall-Bellman lemma, one sufficient condition is attained for the asymptotical stability of a class of nonlinear fractional differential systems whose order lies in (0, 2).

关键词： Asymptotic stability Stability criteria Laplace equations Differential equations Eigenvalues and eigenfunctions Mathematical model

Synthesis of mesoporous nano-TiO_(2)doped with Sn by auto-assembly method and photo-catalytic property

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第5期48卷 436-441页

作者： ZHANG Meihong DING shiwen wang Zhenxing ZHANG Yuzhuo College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China

A series of mesoporous nano-TiO2 material doped with Sn are synthesized by a homogenous precipitation method aided by microwave heating, using TiCl4 and SnCl4 as raw materials, urea as precipitator, active carbon as templet, and soluble starch as anti- agglomer-ating reagent. XRD results show that the precursor exists in the amorphous phase, and trans-forms to anatase structure above 400℃. TEM results show that the particle is in spherical shape and the average diameter is 20 nm. EDS results show that the measuring value of compound is in accord with the actual value of the raw materials, and the doping uniformity is good. The photo-catalytic experimental results show that the highest photo-catalytic efficiency can be ob-tained when the content of Sn is 10% (mol pecent), and the decolorization rate of navy blue dye can be as high as 100% after being illuminated by sunlight for 70 min. The photo-catalytic reac-tion is a first-order kinetic reaction.

关键词： nano-TiO2 doped with Sn, microwave synthesis, template control, homogenous precipitation, mesoporous material, photo-catalysis.

Magnesium promotes vascularization and osseointegration in diabetic states

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 Oral Science 2024年第1期16卷 122-133页

作者： Linfeng Liu Feiyu wang Wei Song Danting Zhang Weimin Lin Qi Yin Qian wang Hanwen Li Quan Yuan shiwen Zhang State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&West China Hospital of Stomatology Sichuan UniversityChengduChina State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases&Department of Oral Implantology West China Hospital of StomatologySichuan UniversityChengduChina

Diabetes has long been considered a risk factor in implant therapy and impaired wound healing in soft and hard oral *** has been proved to promote bone healing under normal ***,we elucidate the mechanism by which Mg^(2+)promotes angiogenesis and osseointegration in diabetic *** generated a diabetic mice model and demonstrated thealveolar bone healing was compromised,with significantly decreased *** then developed Mg-coating implants with hydrothermal *** implants successfully improved the vascularization and osseointegration in diabetic ***,Mg^(2+)promoted the degradation of Kelch-like ECH-associated protein 1 (Keap1) and the nucleation of nuclear factor erythroid 2-related factor 2 (Nrf2) by up-regulating the expression of sestrin 2 (SESN2) in endothelial cells,thus reducing theelevated levels of oxidative stress in mitochondria and relieving endothelial cell dysfunction under ***,our data suggested that Mg^(2+)promoted angiogenesis and osseointegration in diabetic mice by regulating endothelial mitochondria metabolism.

关键词： healing diabetic impaired

Surveillance and Analysis of SARS-CoV-2 Variant Importation—China,January–June 2022

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2022年第50期4卷 1136-1142页

作者： Yenan Feng Xiang Zhao Zeyuan Yin Changcheng Wu Zhixiao Chen Kai Nie Ruhan A Lili Li Peihua Niu Ji wang Yuchao Wu shiwen wang Dayan wang Wenjie Tan Huanyu wang Xuejun Ma George FGao Cao Chen Wenbo Xu National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina National Health Commission Key Laboratory for Medical Virology and Viral Diseases BeijingChina.

Introduction:The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant is the dominant circulating strain *** assess the importation of SARS-CoV-2 variants in the mainland of China during the Omicron epidemic,the genomic surveillance data of SARS-CoV-2 from imported coronavirus disease 2019(COVID-19)cases in the mainland of China during the first half of 2022 were ***:Sequences submitted from January to July 2022,with a collection date before June 30,2022,were *** proportions of SARS-CoV-2 variants as well as the relationships between the origin and destination of each Omicron imported case were ***:4,946 sequences of imported cases were submitted from 27 provincial-level administrative divisions(PLADs),and the median submission interval was within 1 month after *** 3,851 Omicron sequences with good quality,1 recombinant(XU)and 4 subvariants under monitoring(BA.4,BA.5,BA.2.12.1,and BA.2.13)were recorded,and 3 of them(BA.4,BA.5,and BA.2.12.1)caused local transmissions in the mainland of China later than that recorded in the *** subvariants dominated in the first half of 2022 and shifted from BA.1 to BA.2 then to BA.4 and *** percentage of BA.2 in the imported SARS-CoV-2 surveillance data was far higher than that in the Global Initiative on Sharing All Influenza Data(GISAID).The imported cases from Hong Kong Special Administrative Region,China,accounted for 32.30%of Omicron cases sampled,and 98.71%of them were ***:The Omicron variant showed the intra-Omicron evolution in the first half of 2022,and all of the Omicron subvariants were introduced into the mainland of China multiple times from multiple different locations.

关键词： mainland imported submitted