检索结果-南通市图书馆

Helmholtz decomposition with a scalar Poisson equation in elastic anisotropic media

Petroleum Science 2024年第3期21卷 1597-1610页

作者： xin-yu fang Gang Yao Qing-Qing Zheng Ping-Min Zhang Di Wu Feng-Lin Niu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Unconventional Petroleum Research Institute China University of Petroleum (Beijing) Department of Mathematics College of Science China University of Petroleum (Beijing) College of Geophysics China University of Petroleum (Beijing) Department of Earth Environmental and Planetary Sciences Rice University

P-and S-wave separation plays an important role in elastic reverse-time migration. It can reduce the artifacts caused by crosstalk between different modes and improve image quality. In addition, P-and Swave separation can also be used to better understand and distinguish wave types in complex media. At present, the methods for separating wave modes in anisotropic media mainly include spatial nonstationary filtering, low-rank approximation, and vector Poisson equation. Most of these methods require multiple Fourier transforms or the calculation of large matrices, which require high computational costs for problems with large scale. In this paper, an efficient method is proposed to separate the wave mode for anisotropic media by using a scalar anisotropic Poisson operator in the spatial *** 2D problems, the computational complexity required by this method is 1/2 of the methods based on solving a vector Poisson equation. Therefore, compared with existing methods based on pseudoHelmholtz decomposition operators, this method can significantly reduce the computational cost. Numerical examples also show that the P and S waves decomposed by this method not only have the correct amplitude and phase relative to the input wavefield but also can reduce the computational complexity significantly.

关键词： Anisotropic media Scalar anisotropic Poisson equation Improved elastic wavefield decomposition

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

DC performance and AC loss of cable-in-conduit conductors for International Thermonuclear Experimental Reactor

引用

Nuclear Science and Techniques 2016年第3期27卷 176-185页

作者： Wei Zhou xin-yu fang Jin fang Bo Liu School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China Department of Electrical and Computer Engineering University of VictoriaVictoriaBC V8W2Y2Canada Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

A reliable prediction of AC loss is essential for the application of International Thermonuclear Experimental Reactor(ITER) cable-in-conduit conductors(CICCs);however,the calculation of AC loss of ITER CICCs is a cumbersome task due to the complicated geometry of the multistage cables and the extreme operating conditions in *** this paper,we described the models developed for hysteresis and coupling loss calculation,which can be suitable for the construction of ITER magnetic ***,we compared the results of theoretical analysis with the SULTAN test result to evaluate the numerical model we *** addition,we introduced the n-value and AC loss with transport current for CICCs based on the DC measurement results at SULTAN,which lays the foundation for the further study.

关键词：国际热核聚变实验堆交流损耗电缆导体电缆导管直流测量 ITER计划国际热核实验反应堆性能

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

Control of Virtual Synchronous Generator for Frequency Regulation Using a Coordinated Self-adaptive Method

引用

CSEE Journal of Power and Energy Systems 2024年第1期10卷 175-184页

作者： Hongwei fang Zhiwei yu School of Electrical and Information Engineering and Key Laboratory of Tianjin Electric Power System Simulation and Control Tianjin UniversityTianjin 300072China

Power inverter adopting virtual synchronous generator(VSG)control can provide inertia support for distributed generation ***,it cannot take into account the dynamic regulation characteristics of ***,when the system encounters a sudden change in load or disturbance,the dynamic process of frequency regulation will be greatly *** view of this issue,an improved VSG control strategy based on a coordinated self-adaptive(CSA)method is *** time domain analysis method is used to study the influences of virtual inertia and damping parameter perturbation on the system steady and dynamic ***,in order to make the control strategy suitable for large load changes and suppress frequency variations beyond the limit,the secondary frequency modulation is introduced into the control *** the coordinated adaptive control of virtual inertia,virtual damping and frequency modulation,the dynamic performance of vSG frequency regulation can be obviously *** and experiment results have verified the effectiveness of the proposed CSA control strategy.

关键词： Coordinated self-adaptive method frequency regulation time domain analysis virtual synchronous generator

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

Research on Hepatocyte Regulation of PCSK9-LDLR and Its Related Drug Targets

引用

Chinese Journal of Integrative Medicine 2024年第7期30卷 664-672页

作者： LIU Su-su yu Tong QIAO Yan-fang GU Shu-xiao CHAI xin-lou School of Traditional Chinese Medicine Beijing University of Traditional Chinese MedicineBeijing102401China

The prevalence of hyperlipidemia has increased significantly due to genetic, dietary, nutritional and pharmacological factors, and has become one of the most common pathological conditions in humans. Hyperlipidemia can lead to a range of diseases such as atherosclerosis, stroke, coronary heart disease, myocardial infarction, diabetes, and kidney failure, etc. High circulating low-density lipoprotein cholesterol (LDL-C) is one of the causes of hyperlipidemia. LDL-C in the blood binds to LDL receptor (LDLR) and regulates cholesterol homeostasis through endocytosis. In contrast, proprotein convertase subtilisin/kexin type 9 (PCSK9) mediates LDLR degradation via the intracellular and extracellular pathways, leading to hyperlipidemia. Targeting PCSK9-synthesizing transcription factors and downstream molecules are important for development of new lipid-lowering drugs. Clinical trials regarding PCSK9 inhibitors have demonstrated a reduction in atherosclerotic cardiovascular disease events. The purpose of this review was to explore the target and mechanism of intracellular and extracellular pathways in degradation of LDLR and related drugs by PCSK9 in order to open up a new pathway for the development of new lipid-lowering drugs.

关键词： hyperlipidemia proprotein convertase subtilisin/kexin type 9 low-density lipoprotein receptor intracellular pathway extracellular pathway

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

Intracellular RNA Labeling Technologies for the Analysis of RNA Biology

引用

Chinese Journal of Chemistry 2024年第7期42卷 790-801页

作者： Ruiqi Zhao xin fang Xiaocheng Weng Department of Clinical Laboratory Center for Gene DiagnosisDepartment of NeurosurgeryZhongnan Hospital of Wuhan UniversityWuhanHubei 430071China College of Chemistryand Molecular Sciences Key Laboratory of Biomedical Polymers-Ministry of EducationWuhan UniversityWuhan Hubei 430072China

As a cornerstone of the central dogma of molecular biology,RNA plays vital roles in living *** the past few decades,many RNA labeling technologies have been developed to elucidate the biological function of *** technologies have signifi-cantly advanced our understanding of RNA secondary structure,localization,and ***,taking advantage of these innovative RNA labeling approaches,plenty of tool kits have been devised for the regulation of RNA-related biological process,such as gene expression and gene *** this review,we primarily focus on an array of intracellular RNA labeling methods,encom-passing chemical probes-based labeling,metabolic labeling,and proximity-dependent *** also provide a brief overview of their applications in the research of RNA ***,the perspectives of RNA labeling are also discussed.

关键词： RNA Chemical probes Metabolic labeling Proximity-dependent labeling RNA structures Gene sequencing RNA recognition

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

Successful resuscitation after fatal carbon dioxide embolism during laparoscopic nephrectomy

引用

Chinese Medical Journal 2014年第15期127卷 2863-2864页

作者： yu xin fang Xiao fang Xiangming Department of Anaesthesiology the First Affiliated Hospital of Zhejiang University Hangzhou Zhejiang 310012 China

Laparoscopic nephrectomy （LN） is a less invasive surgical option for patients with renal ***,it may be complicated with disastrous CO2 embolism,which is rare but a life-threatening ***,we present a case of lethal CO2 embolism during ***,the complication was detected early and managed *** case and literature review all revealed that gas embolism must be considered as a possible cause of sudden cardiocirculatory failure during LN;rapid diagnosis and definitive intervention can decrease fatality from such an *** mechanisms of CO2 embolism and the potential ways of handling such an event are also ***：laparoscopic nephrectomy; gas embolism; transesophageal echocardiography

关键词： laparoscopic nephrectomy gas embolism transesophageal echocardiography

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

Numerical and experimental analysis of AC loss for CFETR CS model coil

引用

Nuclear Science and Techniques 2017年第10期28卷 79-86页

作者： Wei Zhou xin-yu fang Jin fang Yan-Chao Liu Bo Liu School of Electrical Engineering Beijing Jiaotong University Department of Electrical and Computer Engineering University of Victoria Institute of Plasma Physics Chinese Academy of Sciences

The central solenoid(CS) is an important component of China Fusion Engineering Test Reactor, for producing, forming and stabilizing plasma in the superconducting tokamak. It is a complicated work to design and manufacture the large superconducting CS magnet, so it is meaningful to design a central solenoid model coil(CSMC) and analyze its electromagnetic properties in advance. In this paper, the structure, design parameters and magnetic field distribution of the CS model coil are discussed. The peak power of radial and axial turn conductors and time bucket loss are analyzed by using piecewise-linear method. The CSMC AC loss with different Nb3 Sn CICCs and AC loss of ITER CS coil are compared. The special electrometric method to measure AC loss of the CS model coil for future reference is presented.

关键词： CS模型线圈交流损耗实验堆数值分析托卡马克等离子体磁铁设计 Nb3Sn 聚变工程

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

Sweet Strain Release:Donor-Acceptor Cyclopropane Mediated Glycosylation

引用

CCS Chemistry 2023年第12期5卷 2910-2921页

作者： Xiong Xiao Han Ding Li-Cong Peng xin-yu fang Yang-Yang Qin Qiu-Qi Mu Xue-Wei Liu School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710072 School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological UniversitySingapore 637371

Chemical glycosylation methodologies for the preparation of the bioactive oligosaccharides and glycoconjugates promise reliable access to these compounds as homogeneous materials with welldefined structures in sufficient *** we report a novel activation method of thio(seleno)glycosides employing donor-acceptor cyclopropane(DAC)agents and Sc(OTf)_(3).The Lewis acid catalyst converts DAC into a formal 1,3-zwitterionic species that in turn activates thioglycosides to furnish a glycosyl 1,4-zwitterionic intermediate,interconverting with reactive glycosyl oxocarbenium in the solution with reversible leaving-group *** activation method effectively promotes glycosylation reactions between both armed and disarmed thioglycosides and structurally diverse acceptors,affording oligosaccharides with satisfactory *** usefulness of our activation method has been demonstrated by the mechanism-inspired 2,4-dinitrobenzenesulfonyl(DNs)group directed S_(N)2-like glycosylation and the facile preparation of both linear and branched trisaccharides in one pot via controlled sequential activation of thioglycoside donors.

关键词： glycosylation strain release donor-acceptor cyclopropane glycosyl zwitterion onepot glycosylation

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 low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

引用

Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI Feng GUAN xin fang College of Intelligent Science National University of Defense Technology Naval Research Academy

A metamaterial vibration isolator, termed as wave-insulating isolator, is proposed, which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave insulation. It consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and narrow. The bandgap mechanisms, vibration isolation properties, effects of key parameters, and robustness to complex conditions are clarified. As experimentally demonstrated, the wave-insulating isolator can improve the vibration insulation in the ranges of [50 Hz, 180 Hz] and [260 Hz,400 Hz] by 15 dB and 25 dB, respectively, in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate O328 34A30 74K20

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

Survey on Construction of Safety Case Arguments

引用

Ruan Jian Xue Bao/Journal of Software 2024年第9期35卷

作者： Chen, Ze-Zhong Deng, yu-xin Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai 200062 China

Safety cases provide clear, comprehensive, and reliable arguments which mean that a system’s operation under a specific environment meets acceptable safety levels. In safety-critical sectors subject to regulations such as automotive, aviation, and nuclear industries, certification authorities often require the system to undergo a rigorous safety assessment process and thus demonstrate that the system complies with one or more safety standards. The safety case utilization in system development is an emerging technical means to express the safety attributes of safety-critical systems in a structured and comprehensive way. This study briefly introduces the four basic steps of building a safety case, including determining the goal, gathering evidence, constructing arguments, and evaluating the case, and then focuses on the key step of constructing arguments. Meanwhile, eight existing forms of safety case expressions are introduced in detail, containing goal structuring notation (GSN), claim-argument-evidence (CAE), and structured assurance case metamodel (SACM), with their strengths and weaknesses analyzed. Given the significant complexity of the materials required for safety cases, software tools are often adopted as practical methods for constructing and evaluating safety cases. Additionally, seven tools for developing and evaluating safety cases are compared, including astah system safety, gsn2x, NOR-STA, Socrates, ASCE, D-Case Editor, and AdvoCATE. Furthermore, this study delves into multiple challenges in building safety cases. These challenges include data reliability and integrity, complexity and uncertainty management, inconsistencies in regulations and standards, human factor engineering, rapid technological advancements, and challenges in team and interdisciplinary collaboration. Finally, a prospect is provided for the future development of safety cases to reveal their potential utilization and relevant research problems. © 2024 Chinese Academy of Sciences. Al

关键词： Accident prevention

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

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：