检索结果-南通市图书馆

Science china(Information Sciences) 2012年第7期55卷 1475-1492页

作者： ZHANG GuoQiang 1,2 ,TANG Mingdong 3 ,CHENG SuQi 2,4 ,ZHANG GuoQing 2 ,SONG HaiBin 5 ,CAO JiGuang 6 & YANG Jing 7 1 School of Computer Science and Technology,nanjing Normal University,nanjing 210046,china 2 Institute of Computing Technology,Chinese Academy of Sciences,Beijing 100190,china 3 School of Computer Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,china 4 Graduate University of Chinese Academy of Sciences,Beijing 100190,china 5 nanjing r&d center,huawei technologies,nanjing 2.0012.china 6 china Academy of Telecommunication research of MIIT,Beijing 100191,china 7 china Mobile research Institute,Beijing 100053,china School of Computer Science and Technology Nanjing Normal University Nanjing China Institute of Computing Technology Chinese Academy of Sciences Beijing China School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan China Graduate University of Chinese Academy of Sciences Beijing China nanjing r&d center Huawei Technologies Nanjing China china Academy of Telecommunication research of MIIT Beijing China china Mobile research Institute Beijing China

Peer-to-peer (P2P) based content distribution systems have emerged as the main form for content distribution on the Internet,which can greatly reduce the distribution cost of content providers and improve the overall system ***,the mismatch between the overlay and underlay networks causes large volume of redundant traffic,which intensifies the tension between P2P content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2P *** paper surveys the state-of-art P2P traffic optimization technologies from three perspectives:P2P cache,locality-awareness and data *** details,comparison between these technologies and their applicabilities are presented,followed by a discussion of the issues that remain to be addressed and the direction of future content distribution research.

关键词： P2P traffic localization P2P traffic optimization P2P cache locality-awareness network coding content-centric network

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

P2P:development Situation and Operation Solutions

引用

ZTE Communications 2008年第2期6卷 51-56页

作者： dong Zhenjiang , Qi Chen (Communication Service and Software r&d center, ZTE Corporation, nanjing 2.0012, china)

The rapid development of Peer-to-Peer (P2P) technologies and applications has a great impact on telecom services and operations. Operators should refine the pipeline operation and develop characteristic P2P services. They must comply with the rule of Internet services, and design manageable and operational P2P solutions combining the advantages in network, resource and subscriber, providing users with better P2P service experience. ZTE’s manageable and operational P2P solution provides operators with customized authorization and accounting functions. Its development is based on the broadband service management platform widely used in the live networks. ZTE’s P2P system is stable and reliable.

关键词： node P2P Peer ZTE

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

Maximum Entropy Spectral Estimation Based on Accelerating Genetic Algorithm

Maximum Entropy Spectral Estimation Based on Accelerating Ge...

引用

2009中国控制与决策会议

作者： ZHANG Ming~(1,2),ZHANG Jian-yun~(2,3),JIN Ju-liang~4,WANG Guo-qing~(2,3),HE rui-min~(2,3) 1.State Key Laboratory of Hydrology-water resources and Hydraulic Engineering,Hohai University,nanjing 210098,china. 2.research center for Climate Change,MWr,nanjing,210029,china 3.nanjing Hydraulic research Institute,nanjing 210029,china. 4.School of Civil Engineering,Hefei University of Technology,Hefei 230009,china.

＜正＞The purpose of this paper was to solve the problems of spectral peak shifting and line splitting existing in Burg’s Maximum Entropy Spectral Analysis method（MESA）,to enhance the resolution of entropy spectral,and to increase the adaptability of spectral estimation algorithm to signal length,signal noise ratio and initial phase.A method of accelerating Genetic algorithm based maximum Entropy Spectral estimation method（GES） was proposed,where accelerating genetic algorithm was used to optimize the parameters of MESA and the four equivalent conditions of MESA were used as objective *** typical simulation cases indicated that the phenomenon of spectral peak shifting and line splitting were absent in the frequency spectral estimated by GES,and the ability to discriminate two closed frequency was *** with the traditional MESA methods,GES has good performances in signal processing.

关键词： maximum entropy spectral estimation Burg’s algorithm spectral peak shifting spectral line splitting accelerating genetic algorithm

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

基于VrML-JAVA的可视化装配及其原型系统实现

引用

系统仿真学报 2001年第S2期13卷 586-588页

作者：朱正强孔竞飞吴介一易红东南大学CIMS中心南京210096 东南大学机械工程系南京210096

提出了一种新型的Web环境下3d交互仿真结构。系统采用基于VrML-JAVA的虚拟现实技术,3d模型下载到客户端显示,复杂的运算和仿真在服务器上运行,这种方式可以提高系统的扩展性并降低对客户端软硬件条件的要求。文中对该结构在可视化装配... 详细信息

提出了一种新型的Web环境下3d交互仿真结构。系统采用基于VrML-JAVA的虚拟现实技术,3d模型下载到客户端显示,复杂的运算和仿真在服务器上运行,这种方式可以提高系统的扩展性并降低对客户端软硬件条件的要求。文中对该结构在可视化装配中的应用进行了研究并介绍了其中的关键技术以及原型系统的实现。

关键词： VrML JAVA 装配可视化 Web

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

一种优化的频率域三维声波有限差分模拟方法

引用

地球物理学报 2018年第3期61卷 1095-1108页

作者：范娜成景旺秦雷赵连锋谢小碧姚振兴油气资源与勘探技术教育部重点实验室(长江大学) 武汉430100 非常规油气湖北协同创新中心武汉430100 长江大学地球物理与石油资源学院武汉430100 中石化地球物理公司华东分公司南京211112 中国科学院地质与地球物理研究所中国科学院地球与行星物理重点实验室北京100029 美国加州大学圣克鲁兹分校地球物理与行星物理研究所圣克鲁兹95064

为提高频率域有限差分(Fd,finite-difference)正演模拟技术的计算精度和效率,基于旋转坐标系统的优化差分格式被广泛应用,但是只应用于正方形网格的情况.基于平均导数法(AdM)的优化差分格式,应用于正方形和长方形网格模拟.这些频率域有... 详细信息

为提高频率域有限差分(Fd,finite-difference)正演模拟技术的计算精度和效率,基于旋转坐标系统的优化差分格式被广泛应用,但是只应用于正方形网格的情况.基于平均导数法(AdM)的优化差分格式,应用于正方形和长方形网格模拟.这些频率域有限差分算子,各自具有不同的差分格式和对应的优化系数求解表达式.本文基于三维声波方程发展了一种新的优化方法,只要给定Fd模板形式,可直接构造频散方程,求取Fd模板上各节点的优化系数.此方法的优点在于频率域Fd算子的优化系数对应各个节点,可扩展优化其他格式.运用此优化方法,计算得到了不同空间采样间距比情况下27点和7点格式的优化系数.数值实验表明,优化27点格式与AdM 27点格式具有相同的精度,优化7点格式比经典的7点格式具有更小的数值频散.

关键词：三维声波方程频率域有限差分优化系数

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

Polyketides with potential bioactivities from the mangrove‑derived fungus Talaromyces ***0362

引用

Marine Life Science & Technology 2023年第2期5卷 232-241页

作者： huawei Lv Haibo Su Yaxin Xue Jia Jia Hongkai Bi Shoubao Wang Jinkun Zhang Mengdi Zhu Mahmoud Emam Hong Wang Kui Hong Xing-Nuo Li College of Pharmaceutical Science&Key Laboratory of Marine Fishery resources Exploitment&Utilization of Zhejiang Province Zhejiang University of TechnologyHangzhou 310014China School of Pharmaceutical Sciences Wuhan UniversityWuhan 430072China department of Pathogen Biology&Jiangsu Key Laboratory of Pathogen Biology Nanjing Medical UniversityNanjing 211166China Beijing Key Laboratory of drug Target research and New drug Screening Institute of Materia MedicaChinese Academy of Medical SciencesBeijing 100700China research center of Analysis and Measurement Zhejiang University of TechnologyHangzhou 310014China department of Phytochemistry and Plant Systematics National Research CentreGizaEgypt

Metabolites of microorganisms have long been considered as potential sources for drug *** this study,fve new depsidone derivatives,talaronins A-E(1-5)and three new xanthone derivatives,talaronins F-H(6-8),together with 16 known compounds(9-24),were isolated from the ethyl acetate extract of the mangrove-derived fungus Talaromyces species *** structures were elucidated by analysis of spectroscopic data and chemical methods including alkaline hydrolysis and Mosher’s *** 1 and 2 each attached a dimethyl acetal group at the aromatic ring.A putative biogenetic relationship of the isolated metabolites was presented and suggested that the depsidones and the xanthones probably had the same biosynthetic precursors such as chrysophanol or *** antimicrobial activity assay indicated that compounds 5,9,10,and 14 showed potent activity against Helicobacter pylori with minimum inhibitory concentration(MIC)values in the range of 2.42-36.04μmol/*** secalonic acid d(19)demonstrated signifcant antimicrobial activity against four strains of *** with MIC values in the range of 0.20 to 1.57μmol/***,secalonic acid d(19)exhibited cytotoxicity against cancer cell lines Bel-7402 and HCT-116 with IC_(50) values of 0.15 and 0.19μmol/L,*** structure–activity relationship of depsidone derivatives revealed that the presence of the lactone ring and the hydroxyl at C-10 was crucial to the antimicrobial activity against *** depsidone derivatives are promising leads to inhibit *** and provide an avenue for further development of novel antibiotics.

关键词： Mangrove-derived fungus Talaromyces sp. depsidone Xanthone Antimicrobial

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

Microstructural evolution and mechanical properties of Mg-9.8Gd-2.7Y-0.4Zr alloy produced by repetitive upsetting

引用

Journal of Materials Science & Technology 2018年第7期34卷 1067-1075页

作者： H.Zhou H.Y.Ning X.L.Ma d.d.Yin L.r.Xiao X.C.Sha Y.d.Yu Q.d.Wang Y.S.Li Nano and Heterogeneous Materials center School of Materials and EngineeringNanjing University of Science and TechnologyNanjing210094China Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China School of Mechanical and Electrical Engineering Heilongjiang Institute of TechnologyHeilongjiang 150050China School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040China department of Materials Science&Engineering North Carolina State UniversityRaleighNC 27695USA Key Laboratory of Advanced technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China National Engineering research center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix CompositeShanghai Jiao Tong University200240 ShanghaiChina

A newly developed severe plastic deformation （SPd） technique, i.e. repetitive upsetting （rU）, is employed to improve the strength and ductility of a Mg-Gd-Y-Zr alloy. during the rU processing, dynamic recrystallization occurs in the Mg alloy, which leads to a significant grain refinement from 11.2 p.m to 2.8 μm. The yield strength （YS）, ultimate tensile strength （UTS） and elongation increase simultaneously with increasing rU passes. The microstructural evolution is affected by processing temperatures. dynamic recrystallization prevails at low temperatures, while dynamic recovery is the main effect factor at high temperatures. Texture characteristics gradually become random during multiple passes of rU processing, which reduces the tension-compression asymmetry of the Mg-Gd-Y-Zr alloy. 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

关键词： Severe plastic deformation (SPd) repetitive upsetting (rU) Mg-rE alloy Mechanical properties

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

Preventing autosomal-dominant hearing loss in Bth mice with CrISPr/Casrx-based rNA editing

引用

Signal Transduction and Targeted Therapy 2022年第4期7卷 1258-1270页

作者： Ziwen Zheng Guo Li Chong Cui Fang Wang Xiaohan Wang Zhijiao Xu Huiping Guo Yuxin Chen Honghai Tang daqi Wang Mingqian Huang Zheng-Yi Chen Xingxu Huang huawei Li Geng-Lin Li Xiaoxiang Hu Yilai Shu ENT Institute and department of Otorhinolaryngology Eye&ENT HospitalState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghai 200031China Institutes of Biomedical Sciences Fudan UniversityShanghai 200032China NHC Key Laboratory of Hearing Medicine(Fudan University) Shanghai 200032China State Key Laboratory of Agrobiotechnology China Agricultural UniversityBeijing 100193China College of Biological Sciences China Agricultural UniversityBeijing 100193China School of Life Science and Technology Southeast UniversityNanjing 210096China department of Otolaryngology-Head and Neck Surgery Graduate Program in Speech and Hearing Bioscience and Technology and Program in NeuroscienceHarvard Medical SchoolBostonMA 02115USA Eaton-Peabody Laboratory Massachusetts Eye and Ear InfirmaryBostonMA 02114USA School of Life Science and Technology ShanghaiTech UniversityShanghai 200031China CAS center for Excellence in Molecular Cell Science Shanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 200031China Institutes of Brain Science and the Collaborative Innovation center for Brain Science Fudan UniversityShanghai 200031China

CrISPr/rfxCas13d(Casrx)editing system can specifically and precisely cleave single-strand rNAs,which is a promising treatment for various disorders by downregulation of related gene ***,we tested this rNA-editing approach on Beethoven(Bth)mice,an animal model for human dFNA36 due to a point mutation in *** first screened 30 sgrNAs in cell cultures and found that Casrx with sgrNA3 reduced the Tmc1^(Bth)transcript by 90.8%,and the Tmc1 wild type transcript(Tmc1^(+))by 44.3%.We then injected a newly developed AAV vector(***)based Casrx into the inner ears of neonatal Bth mice,and we found that Tmc1^(Bth)was reduced by 70.2%in 2 weeks with few off-target effects in the whole ***,we found improved hair cell survival,rescued hair bundle degeneration,and reduced mechanoelectrical transduction ***,the hearing performance,measured in both ABr and dPOAE thresholds,was improved significantly in all ages over 8 ***,therefore,have validated the CrISPr/Casrx-based rNA editing strategy in treating autosomal-dominant hearing loss,paving way for its further application in many other hereditary diseases in hearing and beyond.

关键词： CrISPr/Cas editing hearing

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

隧道爆破振动下既有建筑结构动力响应及损伤研究综述

引用

土木工程学报 2019年第A1期52卷 151-158页

作者：管晓明聂庆科李华伟安建永青岛理工大学山东青岛266033 河北建设勘察研究院有限公司河北石家庄050031 河北省岩土工程研究中心河北石家庄050031 中国建筑第二工程局有限公司北京100160

针对隧道爆破振动引起建筑结构的损伤问题,首先阐述隧道爆破振动峰值振速和频率的衰减规律;然后总结隧道爆破下采用反应谱法、时程分析法、损伤指数量化法和现场试验测试法得出的结构振动反应特征,阐述隧道爆破下建筑结构的损伤机理和... 详细信息

针对隧道爆破振动引起建筑结构的损伤问题,首先阐述隧道爆破振动峰值振速和频率的衰减规律;然后总结隧道爆破下采用反应谱法、时程分析法、损伤指数量化法和现场试验测试法得出的结构振动反应特征,阐述隧道爆破下建筑结构的损伤机理和易损构件,并探究了基于高阶局部模态的爆破振动下结构振动的损伤机理;阐述振动安全标准及改进方法;最后指出今后的研究重点:①建立同时考虑结构承重构件和非承重构件的三维全结构模型,探究爆破振动下非承重构件的振动反应及损伤情况;②基于结构动力学和高阶模态理论,通过分析爆破振动主频与结构高阶模态频率之间的关系,探索建筑结构在隧道爆破下的高阶模态振动效应及损伤特征;③需要综合考虑结构峰值振速—峰值应力的耦合响应特征来探究建筑结构在隧道爆破振动下的损伤机理,辨识易损构件,改进和完善爆破振动安全标准;④结合大数据、信息化和结构健康监测技术,实现动态化、定量化和精细化评价爆破振动下建筑物安全和结构损伤。

关键词：隧道工程爆破振动建筑结构动力反应损伤机理高阶模态安全标准

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

Effect of Y content and equal channel angular pressing on the microstructure, texture and mechanical property of extruded Mg-Y alloys

引用

Journal of Magnesium and Alloys 2022年第1期10卷 210-224页

作者： W.Yang G.F.Quan B.Ji Y.F.Wan H.Zhou J.Zheng d.d.Yin Key Laboratory of Advanced technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China Nano and Heterogeneous Materials center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringShenyang National Laboratory for Materials ScienceChongqing UniversityChongqing 400044China

The microstructure, texture and mechanical property evolution of the extruded Mg-x Y(x = 1, 5 wt.%) alloys during equal channel angular pressing(ECAP) were systematically investigated using an optical microscope, electron backscatter diffraction(EBSd) and uniaxial tensile test. The Mg-Y alloys exhibited a weakened basal texture before the ECAP, and the texture was further weakened with the max basal poles dispersed along ~45° between the extrusion direction and the transverse direction after the ECAP. The Mg-5 Y alloys always exhibited a finer grain size comparing to that of Mg-1 Y for the same ECAP process. With a proper ECAP process, both the strength and elongation of Mg-5 Y alloy could be improved simultaneously after the ECAP, i.e., the yield strength(273.9 ± 1.2 MPa), ultimate strength(306.4 ± 3.0 MPa),and elongation(23.9 ± 1.0%) were increased by 10%, 6%, and 72%, respectively, comparing to that before the ECAP. This was considered to be arose from the combined effects of grain refinement, significant improved microstructure homogeneity and solid solution *** addition, it was found that Mg-Y alloy with better comprehensive properties could be obtained by the decreasing-temperature ECAP processes. The yield strength-grain size relationship could be well described by the Hall-Petch relation for all the ECAPed Mg-Y alloys,which was consistent with that the texture changes did not significantly affect the average Schmid factors of basal, prismatic and pyramidal slips for both Mg-Y alloys.

关键词： Mg-rE alloy Equal channel angular pressing Texture Mechanical property

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：