检索结果-南通市图书馆

Failure Envelopes of Single-Plate Rigid Helical Anchors for Floating Offshore Wind Turbine

China Ocean Engineering 2023年第6期37卷 1000-1010页

作者： CHEN Hong-zhen WANG Le TIAN Ying-hui zhang chun-hui SHEN Zhi-chao LIU Meng-meng State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Department of Infrastructure Engineering Faculty of Engineering and Information Technology The University of MelbourneVictoria 3010Australia School of Civil Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Hebei Technological Innovation Center of Disaster Prevention and Mitigation Engineering of Geotechnical and Structural System Shijiazhuang 050018China School of Marine Science and Engineering South China University of TechnologyGuangzhou 511442China Institute of Ocean Energy and Intelligent Construction Tianjin University of TechnologyTianjin 300384China

Helical anchor is a kind of novel foundation for floating offshore wind turbines,which should be subjected to combined tensile loading caused by wind,wave and ***,the research about the capacity of helical anchor was mainly examined under uniaxial loading and scarcely explored under combined *** this study,three-dimensional finite element limit analysis is adopted to assess the bearing capacities of single-plate rigid helical anchors with different ratios of helix to shaft diameter,D_(H)/D_(S) and embedment ratios L/D_(S).Result shows that the vertical,horizontal and moment bearing capacities increase with increasing D_(H)/D_(S) and L/D_(S).The normalized V-H failure envelopes expands with increasing L/D_(S),while the normalized V-M failure envelopes tend to contract with the increase of D_(H)/D_(S).With increasing D_(H)/D_(S) or decreasing L/D_(S),the normalized H-M failure envelopes expand when the horizontal and moment loading act in the same direction and contract when they act in the opposite *** effect of D_(H)/D_(S) and L/D_(S) on the shape of H-M failure envelope become insignificant when L/D_(S)≥4.A series of failure mechanisms under different loading conditions were observed and can be used to explain the ***,a series of approximate expressions were proposed to fit the uniaxial bearing capacities and the failure envelopes.

关键词： helical anchors bearing capacity failure envelope clay

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

HISTORICAL DESERTIFICATION PROCESS IN HEXI CORRIDOR,CHINA

引用

Chinese Geographical Science 2005年第3期15卷 245-253页

作者： WANG Nai-ang zhang chun-hui LI Gang CHENG Hong-yi College of Earth and Environment Sciences Lanzhou University Lanzhou 730000P. R. China

Over the last 2000 years, approximately 38 ancient cities were abandoned through desertification in Hexi Corridor, Northwest China. Among them, 21.05% were abandoned during the Northern and Southern Dynasties, 21.05% during the end of the Tang Dynasty and the Five Dynasties, and 57.9% during the Ming and Qing dynasties. At the same time, main lakes were shrinking rapidly from the 5th Century to the 6th Century and the end of the Qing Dynasty. The climate in these periods was relatively arid and cold with frequent dusts. The phase of these changes indicated that there were three periods of desertification enlargement in the northern China. They were Northern and Southern Dynasties, the end of Tang Dynasty and Five Dynasties, the Ming and Qing dynasties. The macro-process of desertification in the study area was controlled mainly by the climatic changes. But from the facts that the population density in the middle of Qing Dynasty had exceeded the critical index of population pressure in arid area and the usage rate of water resources had exceeded 40% in Hexi Corridor, this paper also suggests that human activities have played an important role in desertification processes of the study area mainly during the recent 300 years.

关键词： historical desertification climate change human activities Hexi Corridor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Model of coupled gas flow and deformation process in heterogeneous coal seams and its application

引用

Journal of Coal Science & Engineering(China) 2011年第1期17卷 76-80页

作者： zhang chun-hui ZHAO Quan-sheng YU Yong-jiang School of Civil Engineering Hebei University of Science and Technology Shijiazhuang 050018 China College of Mechanics and Engineering Liaoning Technical University Fuxin 123000 China

The heterogeneity of coal was studied by mechanical tests. Probability plots of experimental data show that the mechanical parameters of heterogeneous coal follow a Weibull distribution. Based on elasto-plastic mechanics and gas dynamics, the model of coupled gas flow＇ and deformation process of heterogeneous coal was presented and the effects of heterogeneity of coal on gas flow and failure of coal wcrc investigated. Major findings include： The effect of the heterogeneity of coal on gas flow and mechanical thilure of coal can be considered by the model in this paper. Failure of coal has a great effect on gas flow.

关键词： Heterogeneity Weibull distribution coupled model mechanical tests

来源：

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

Rock matrix-fractured media model for heterogeneous and fractured coal bed

引用

中国有色金属学会会刊：英文版 2011年第S3期21卷 621-625页

作者： zhang chun-hui1, YU Guang-ming2, zhang chun1 1. School of Civil Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China 2. School of Civil Engineering, Qingdao Technological University, Qingdao 266033, China School of Civil Engineering Hebei University of Science and Technology Shijiazhuang 050018 China School of Civil Engineering Qingdao Technological University Qingdao 266033 China

Coal was considered rock matrix-fractured media composed of rock matrix and fractures, and the rock matrix-fractured media model for heterogeneous and fractured coal bed was presented. In this model the rock matrix is heterogeneous, and the mechanical parameters such as elastic modulus and strength follow Weibull distribution. Fractures in coal bed were generated with the discrete fracture network method, and the properties of fractures were simulated with Desai element. Then the virtual generating system (VGS) of natural heterogeneous and fractured coal bed was developed in Matlab 6.0. The coupled model of gas flow and deformation process based on the rock matrix-fractured media model method and VGS for heterogeneous and fractured coal bed was presented, and the numerical code was developed in Matlab 6.0. The gas flow process in the heterogeneous and fractured coal bed was simulated in a numerical case. The main conclusions are: 1) The natural heterogeneous and fractured coal bed could be simulated by the rock matrix-fractured media model and VGS; 2) The fractures connected with the well have much more effects on gas flow than those non-connected.

关键词： heterogeneity fractures rock matrix-fractured media

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Detection of Beta-Lactamase and Extended-Spectrum Beta-Lactamase of Pathogens Isolated from Pig and Chicken and Their Antibiotic Susceptibility Test

引用

Agricultural Sciences in China 2005年第11期4卷 877-882页

作者： HU Gong-zheng zhang chun-hui YUAN Li YANG Yu-rong LIANG Jun Faculty of Animal Husbandary and Veterinary Science Henan Agricultural University Zhengzhou 450002 P.R.China Zhengzhou College of Animal Husbandary Engineering Zhengzhou 450006 P.R.China

The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase- producing strains, lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected, respectively, for beta-lactamase and extended-spectrum beta- lactamases （ESBLs）, The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs. All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin. MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively, when it was conbined with sulbactam at ration of 1：2 and 1：4. All clinical isolates were susceptible to third-generation cephalosporins. The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam. MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.

关键词： Beta-lactamase Extended-spectrum beta-lactamase Inhibitor Antibiotic susceptibility test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanics Principle and Engineering Application of Split Layer and Bed Separation of Mining Overburden

引用

地球与环境 2005年第B10期33卷 17-26页

作者： YU Guang-ming zhang chun-hui SU Zhong-jie FAN Xue-li PAN Yong-zhan LIU Fu-shun Civil engineering institute Qingdao Technological University Qingdao 266033 Engineering college Ocean University of China Qingdao 266071 Liaoning Technical University Fuxin 123000

To control land surface subsidence caused the underground mineral exploitation and the catastrophic phenomena such as serious damage of buildings, waterbodies, cultivated lands, railways, bridges caused by land subsidence, bed separation grouting technology of overburden is put forward. To provide theoretical support for the technology, the characteristics and the mechanics mechanism of mining overburden from layer-split to formation of bed separation are studied. On the basis of elastic sheet board theory, calculation formula of rock sheet deflection is presented, and the mechanics criteria of the separation formation and the calculation formula of bed separation volume are set up. Finally, the applications and technics of bed separation grout technology of mining overburden to control land subsidence in china are introduced.

关键词：矿井承载力岩石力学岩层沉陷偏斜现象

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inhibitory effect of triptolide on lymph node metastasis in patients with non-Hodgkin lymphoma by regulating SDF-1/CXCR4 axis in vitro

引用

Acta Pharmacologica Sinica 2006年第11期27卷 1438-1446页

作者： chun zhang Guo-hui CUI Fang LIU Qiu-ling WU Yan CHEN~2 Department of Hematology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,China Department of Hematology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To investigate the antiproliferative effect of triptolide on B-NHL cell line Rajicells,to study its effect on lymph node metastasis in patients with non-Hodgkin’slymphoma(NHL)in vitro,and to explore the underlying mechanism regulatingSDF-1/CXCR4 ***:The effects of triptolide on the growth of Raji cellswere studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium(MTT)*** effects of triptolide on SDF-1 mRNA expression in lymph node stromalcells from patients with NHL were determined by reverse transcriptase-polymerasechain reaction(RT-PCR).The effects of triptolide on CXCR4 expression on lym-phoma cells freshly isolated from the lymph nodes of these patients were studiedby flow cytometric *** assays were performed to observe theeffects of triptolide on migration of primary lymphoma cells towards recombinanthuman SDF-1α(rhSDF-1α)or cultured lymph node stromal cells in ***:Triptolide inhibited the proliferation of B-NHL cell line Raji cells in a dose-andtime-dependent manner with a 24-h IC50value of 43.06 nmol/L and a 36-h IC50valueof 25.08 nmol/*** expression of SDF-1α mRNA in lymph node stromal cellsobtained from patients with NHL was decreased after treatment by triptolide atconcentrations of 25 and 50 nrnol/L for 24 *** cytometry analysis showed thatthe CXCR4 expression on primary lymphoma cells were downregulated graduallyin a dose-dependent manner following triptolide *** assaysrevealed that the migration of freshly isolated lymphoma cells towards either rhSDF-1or cultured lymph node stromal cells was markedly inhibited by the addition oftriptolide in vitro,and the inhibition was ***:Triptolidecan inhibit the proliferation of B-NHL cell line Raji ***,triptolide isable to inhibit the migration of lymphoma cells via lymph nodes in *** antitumor mechanisms of triptolide are related to the antiproliferativeeffect and the blockage of SDF-1/CXCR4

关键词： triptolide Raji metastasis non-Hodgkin’s lymphoma stromal cell-derived factor-1 CXCR4

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Separation,Purification and Characterization of Three Endo-polygalacturonases from a Newly Isolated Penicillum oxalicum

引用

过程工程学报 2009年第2期9卷 242-249页

作者：张春晖李祖明彭霞薇贾月张洪勋白志辉 Teacher＇s College of Beijing Union University Beijing 100011 China School of Chemical ＆ Environmental Engineering China University of Mining ＆ Technology (Beijing) Beijing 100083 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Three endo-polygalacturonases(endoPGs) from a newly isolated Penicillum oxalicum(CGMCC 0907) capable of utilizing waste biomass as growth substrate were separated and purified to homogeneity by ultra-filtration,affinity adsorption chromatography,CM-cellulose column chromatography,and Sephadex G-100 gel filtration chromatography with the overall yield of 64.5% from the crude *** specific activities and recovery rates of endoPG-1,endoPG-2 and endoPG-3 were 1120 U/mg and 21.6%,1350 U/mg and 25.9%,and 1560 U/mg and 17.0%,*** three purified endoPGs had a close molecular weight to 41 kDa as estimated by *** optimum temperature and pH for the function of them were 65℃ and 5.0,55℃ and 5.0,50℃ and 5.5,*** pI and Km values were 5.9 and 0.78 mg/mL,6.0 and 1.2 mg/mL,and 6.1 and 2.0 mg/mL,respectively.

关键词：多聚半乳糖醛酸酶分离提取净化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于PL-EPLL的未知时变窄带噪声有源控制方法

引用

电子学报 2020年第6期48卷 1140-1148页

作者：刘锦春张春辉沈惠杰袁建福州大学机械工程及自动化学院福建福州350108 海军研究院北京100161 海军工程大学湖北武汉430033 山东理工大学交通与车辆工程学院山东淄博266018

针对船舶动力机械装置未知时变窄带噪声的有源控制问题,基于锁相环信号跟踪生成原理,通过在锁相环中引入次级通道执行机构,推导了新的未知时变窄带噪声有源控制方法.首先,通过EPLL(Enhanced Phase Locked Loop)环节中引入次级通道,形成... 详细信息

针对船舶动力机械装置未知时变窄带噪声的有源控制问题,基于锁相环信号跟踪生成原理,通过在锁相环中引入次级通道执行机构,推导了新的未知时变窄带噪声有源控制方法.首先,通过EPLL(Enhanced Phase Locked Loop)环节中引入次级通道,形成基于EPLL的未知时变窄带噪声有源控制方法;其次,通过近似分析得到其等效线性差分方程,研究了窄带噪声信号幅值和次级通道特性对算法收敛性能的影响;再次,通过引入幅值归一化和次级通道归一化改进措施,提出了基于Pseudolinear(PL)-EPLL的窄带噪声控制方法.相比原方法,改进算法幅值、频率/相位收敛方程的收敛特性与窄带噪声信号幅值和次级通道特性无关,对不同强度分量的多频窄带噪声控制,具有较为一致的收敛速度.最后,通过仿真分析,验证所提出方法的有效性.

关键词：噪声抵消锁相环时变窄带噪声

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于ARCGIS的矿山开采沉陷灾害预警系统

引用

岩土力学 2009年第7期30卷 2197-2202页

作者：张春会赵全胜河北科技大学建筑工程学院石家庄050018

为了实现与环境协调的矿产资源开采,提出建立并开发了矿山开采沉陷灾害预警系统。以美国大型软件ARCGIS为开发平台,采用ARCMapObject开发方法开发了矿山开采沉陷灾害预警系统;建立了该系统计算参数的位移反分析模型,引入单纯形优化方法... 详细信息

为了实现与环境协调的矿产资源开采,提出建立并开发了矿山开采沉陷灾害预警系统。以美国大型软件ARCGIS为开发平台,采用ARCMapObject开发方法开发了矿山开采沉陷灾害预警系统;建立了该系统计算参数的位移反分析模型,引入单纯形优化方法,编制了系统计算参数的位移反分析模块;进行了实例计算分析。第1个实例分析了某工作面开采引起的地表沉陷灾害,并与CXYJ2001的计算结果对比,验证了系统的计算可靠性,并展示了系统的功能。第2个实例是对江苏姚桥煤矿开采方案引起的地表沉陷灾害预警分析,优化了开采方案。研究表明,系统是实现与环境协调的矿产资源开采的重要辅助手段。最后,介绍了进一步工作的方向。

关键词： ARCGIS 矿山开采沉陷灾害预警系统位移反分析单纯形法

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：