检索结果-南通市图书馆

Landform classification based on landform geospatial structure-a case study on Loess Plateau of China

International Journal of Digital Earth 2022年第1期15卷 1125-1148页

作者： Siwei Lin Jing Xie Jiayin Deng Meng qi Nan Chen Key Laboratory of Spatial Data Mining & Information Sharing Ministry of EducationFuzhou UniversityFuzhouPeople’s Republic of China The Academy of Digital China (Fujian) Fuzhou UniversityFuzhouPeople’s Republic of China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China University of Chinese Academy of Sciences BeijingPeople’s Republic of China

Landform classification,which is a key topic of geography,is of great significance to a wide range of fields including human construction,geological structure research,environmental governance,*** studies of landform classification generally paid attention to the topographic or texture information,whilst the watershed spatial structure has not been *** study developed a new landform classification method based on watershed geospatial *** abstracting the landform into the internal and marginal structure,we adopted the gully weighted complex network(GWCN)and watershed boundary profile(WBP)to simulate the watershed geospatial *** various indices to quantitatively depict the watershed geospatial structure,we conducted the landform classification on the Northern Shaanxi of Loess Plateau with a watershed-based strategy and established the classification *** classified landform distribution has significant spatial aggregation and clear regional *** accuracy reached 89%and the kappa coefficient reached 0.87%.Besides,the proposed method has a positive response to some similar and complex *** general,the present study first utilized the watershed geospatial structure to conduct landform classification and is an efficient landform classification method with well accuracy and universality,offering additional insights for landform classification and mapping.

关键词： DEM landform classification geomorphological mapping watershed geospatial structure complex network

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

A Review on Rill Erosion Process and Its Influencing Factors

引用

Chinese Geographical Science 2013年第4期23卷 389-402页

作者： SUN Liying FANG Haiyan qi Deli LI Junlan Cai qiangguo Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources

Rills are frequently observed on slope farmlands and rill erosion significantly contributes to sediment yields. This paper focuses on reviewing the various factors affecting rill erosion processes and the threshold conditions of rill initiation. Six factors, including rainfall, runoff, soil, topography, vegetation and tillage system, are discussed. Rill initiation and network are explored. Runoff erosivity and soil erodibility are recognized as two direct factors affecting rill erosion and other types of factors may have indirect influences on rill erosion through increasing or decreasing the effects of the direct factors. Certain conditions are necessary for rill initiation and the critical conditions are different with different factors. Future studies should be focused on 1) the dynamic changes of rill networks; 2) the combined effect of multiple factors; and 3) the relationships of threshold values with other related factors.

关键词： rill initiation rill erosion rill network critical condition

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

Advanced continuous phase modulation for high mobility communications

引用

Chinese Science Bulletin 2014年第35期59卷 4999-5010页

作者： Bing Li Baoming Bai Tor Aulin qi Li State Key Laboratory of ISN Xidian University Department of Computer Science Chalmers University of Technology

This paper focuses on the design of continuous phase-modulated systems and simplified receiver for highmobility wireless communications.A class of spectrally efficient coded modulation systems is proposed and analyzed in terms of Euclidean distance and spectral ***,the simplified detector based on mismatched receiver is designed to reduce the detection complexity exponentially for partial response *** deal with the fast time-varying channels without channel state information,a class of noncoherent detection algorithms for continuous phase modulation systems is developed to offer near-coherent *** proposed system is assessed over both the additive white Gaussian noise and fast-fading *** and simulated results show that the proposed system offers not only high spectral efficiency but also near-optimum performance over fast time-varying scenarios.

关键词：连续相位调制无线通信高流动性编码调制系统高频谱效率加性白高斯噪声非相干检测信道状态信息

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

Self-assembly with varying hydrophobic centers:Synthesis of red blood cell-like basic magnesium carbonate microspheres

引用

Particuology 2015年第5期13卷 145-150页

作者： Xinlong Ma Guoqing Ning Bing Chen Chuanlei qi Xingying Lan Jinsen Gao State Key Laboratory of Heavy Oil Processing China University of Petroleum

Basic magnesium carbonate microspheres with a red blood cell （RBC）-like appearance and diameters of ~3μm were synthesized by amphiphilic molecule-participated self-assembly under hydrothermal conditions, In the self-assembly, sodium dodecyl benzene sulfonate served as a template for the formation of Mg（OH）2 spherical micelles and also as a reactant precursor that releases CO2 to react with Mg（OH）2. The growth of the microspheres is driven by the continuous generation of new hydrophobic centers because of the consumption of hydrophilic poles （--SO3-）. The surfactant-directed self-assembly can be applied to the synthesis of other carbonate or metallic oxide self-assemblies, indicating that it is a universal self-assembly method for amphiphilic molecules.

关键词： Self-assembly Red blood cell-like Basic magnesium carbonate Microspheres

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 Si on high temperature oxidation of 30Cr13 stainless steel

引用

Journal of Iron and Steel Research International 2017年第5期24卷 561-568页

作者： Hong-huan Mao Xing qi Jing Cao Li-cong An Yi-tao Yang School of Materials Science and Engineering Shanghai University Shanghai 200072 China

The effect of Si on the high temperature oxidation behavior of the 30Cr13 martensitic stainless steels was investigated. The underlying mechanism was further discussed by oxidation kinetics curves, scanning electron microscopy （SEM） and X-ray diffraction （XRD） analysis. It was ob- served that the addition of Si can significantly reduce the mass gain per unit area and the oxidation rate of the experimental steels. With the increase of Si content, the film surface composed of the wheat-like oxides turned into the small granular oxides after oxidation for 120 h. The SiO_2 film formed on the metal substrate inhibited the outward diffusion of the metal cation and the inward diffusion of the oxygen anion; thus, the high temperature oxidation resistance was enhanced.

关键词： Metallic material Martensitic stainless steel High temperature oxidation Oxidation kinetics

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

Route Guardian: Constructing Secure Routing Paths in Software-Defined Networking

引用

Tsinghua Science and Technology 2017年第4期22卷 400-412页

作者： Mengmeng Wang Jianwei Liu Jian Mao Haosu Cheng Jie Chen Chan qi School of Electronic and Information Engineering Beihang University

Software-Defined Networking（SDN） decouples the control plane and the data plane in network switches and routers, which enables the rapid innovation and optimization of routing and switching configurations. However,traditional routing mechanisms in SDN, based on the Dijkstra shortest path, do not take the capacity of nodes into account, which may lead to network congestion. Moreover, security resource utilization in SDN is inefficient and is not addressed by existing routing algorithms. In this paper, we propose Route Guardian, a reliable securityoriented SDN routing mechanism, which considers the capabilities of SDN switch nodes combined with a Network Security Virtualization framework. Our scheme employs the distributed network security devices effectively to ensure analysis of abnormal traffic and malicious node isolation. Furthermore, Route Guardian supports dynamic routing reconfiguration according to the latest network status. We prototyped Route Guardian and conducted theoretical analysis and performance evaluation. Our results demonstrate that this approach can effectively use the existing security devices and mechanisms in SDN.

关键词： Software-Defined Networking(SDN) network security virtualization capacity-based routing security oriented routing dynamic routing reconfiguration

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

Two new steroidal glycosides from Ophiopogon japonicus

引用

Chinese Chemical Letters 2008年第9期19卷 1086-1088页

作者： YiFeng Zhou Jin qi Dan Ni Zhu BoYang Yu Department of Complex Prescription of TCM China Pharmaceutical University 1 Shennong Road Nanjing 210038 China

Two new C27-steroidal glycosides were isolated from the fibrous roots of Ophiopogon japonicus. The spectral analysis and chemical evidence revealed their chemical structures to be （25R）-spirost-5,14-dien-3β-yl-O-α-L-rhamnopyranosyl-（1 → 2）-β-D- xylopyranosyl-（1 → 4）-β-D-glucopyranoside （1） and ophiogenin 3-O-β-D-glucopyranoside （2）.

关键词： Ophiopogon japonicus Liliaceae C27-steroidal glycoside

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

The Rheological Property and Foam Morphology of Linear Polypropylene and Long Chain Branching Polypropylene

引用

Journal of Wuhan University of Technology(Materials Science) 2013年第4期28卷 798-803页

作者：黄锦涛 HE Guangjian 廖霞 HUANG Yajiang YANG qi College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Key Laboratory of Polymer Processing Engineering Ministry of Education South China University of Technology

The rheological behavior, thermal properties and foam morphology of linear polypropylene and long chain branching polypropylene prepared through UV irradiation reactive extrusion were studied by rheological test, melt index test, DSC and supercritical carbon dioxide foaming technology. Rheological test and melt index test confirmed that under UV irradiation and extrusion, adding photo-initiator and cross- linking agent could achieve the purpose of branching, thus improved the melt strength of polypropylene effectively. The DSC results revealed that with the introducing of long chain branching, the melting range of the polypropylene broadened and the crystallization temperature increased. Owing to the introduction of long chain branches, polypropylene exhibited higher melt strength and strain hardening behavior. Compared with linear polypropylene, the foam morphologies of long chain branching polypropylene were more uniform.

关键词： polypropylene long chain branching rheological behavior supereritical CO2 foaming

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

A Novel Shilling Attack Detection Model Based on Particle Filter and Gravitation

引用

China Communications 2019年第10期16卷 112-132页

作者： Lingtao qi Haiping Huang Feng Li Reza Malekian Ruchuan Wang College of Computer Nanjing University of Posts and TelecommunicationsNanjing 210003China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003China “Broadband Wireless Communication and Sensor Network Technology”Key Lab of Ministry of Education NUPTNanjing 210003China College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Computer Science and Media Technology Malmo UniversityMalmo 20506Sweden

With the rapid development of e-commerce, the security issues of collaborative filtering recommender systems have been widely investigated. Malicious users can benefit from injecting a great quantities of fake profiles into recommender systems to manipulate recommendation results. As one of the most important attack methods in recommender systems, the shilling attack has been paid considerable attention, especially to its model and the way to detect it. Among them, the loose version of Group Shilling Attack Generation Algorithm (GSAGenl) has outstanding performance. It can be immune to some PCC (Pearson Correlation Coefficient)-based detectors due to the nature of anti-Pearson correlation. In order to overcome the vulnerabilities caused by GSAGenl, a gravitation-based detection model (GBDM) is presented, integrated with a sophisticated gravitational detector and a decider. And meanwhile two new basic attributes and a particle filter algorithm are used for tracking prediction. And then, whether an attack occurs can be judged according to the law of universal gravitation in decision-making. The detection performances of GBDM, HHT-SVM, UnRAP, AP-UnRAP Semi-SAD,SVM-TIA and PCA-P are compared and evaluated. And simulation results show the effectiveness and availability of GBDM.

关键词： shilling attack detection model collaborative filtering recommender systems gravitation-based detection model particle filter algorithm

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

An effective system for detecting protein-protein interaction based on in vivo cleavage by PPV NIa protease

引用

Protein & Cell 2012年第12期3卷 921-928页

作者： Nuoyan zheng Xiahe Huang Bojiao Yin Dan Wang qi Xie Department of Nephrology the First Affiliated HospitalSun Yat-Sen UniversityGuangzhou 510000China Research Center of Translational Medicine the First Affiliated HospitalSun Yat-Sen UniversityGuangzhou 510000China State Key Laboratory of Plant Genomics National Centre for Plant Gene ResearchInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Animal Center Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China

Detection of protein-protein interaction can provide valuable information for investigating the biological function of *** current methods that applied in protein-protein interaction,such as co-immunoprecipitation and pull down etc.,often cause plenty of working time due to the burdensome cloning and puri-fication *** we established a system that characterization of protein-protein interaction was accomplished by co-expression and simply purification of target proteins from one expression cassette within *** *** modified pET vector into co-expression vector pInvivo which encoded PPV NIa protease,two cleavage site F and two multiple cloning sites that flanking cleavage *** target proteins(for example:protein A and protein B)were inserted at multiple cloning sites and translated into polyprotein in the order of MBP tag-protein A-site F-PPV NIa protease-site F-protein B-His6 *** NIa protease carried out intracellular cleavage along expression,then led to the separation of polyprotein components,therefore,the interaction between protein A-protein B can be detected through one-step purification and *** control for protein B was brought into this system for monitoring interaction *** successfully employed this system to prove two cases of reported protien-protein interaction:RHA2a/ANAC and FTA/*** conclusion,a convenient and efficient system has been successfully developed for detecting protein-protein interaction.

关键词： PPV NIa protease protein-protein interaction in vivo cleavage fusion protein

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：