检索结果-南通市图书馆

Partition-based Network Equivalent Method for Power System Subsynchronous Oscillation Analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 313-320页

作者： Chenxuan Wang Weimin Zheng Zhen Wang Yangqing Dan Ping ju the Department of Electrical Engineering Zhejiang UniversityHangzhou 310027China the Economic Research Institute of State Grid Zhejiang Electric Power Co. Ltd.Hangzhou 310016China the College of Energy and Electrical Engineering Hohai UniverstiyNanjing 211100China

Given large-scale modern power systems with pow er electronic converters,the numerical simulation with subsyn chronous oscillation(SSO)faces great challenges in engineering practice due to sharply enlarged modeling scale and high com putational *** reduce the modeling scale,network parti tion and equivalent becomes a vital technique in numerical sim *** several methods have been developed for net work equivalent,a generally accepted rule for network parti tion is still *** paper proposes that the system can be partitioned into three parts,i.e.,the internal,the middle,and the external subsystems,in which the internal subsystem consists of all power electronic components,the middle subsys tem includes those selected AC dynamic components with de tailed models,and the remaining components and buses consti tute the external *** external subsystem is further represented by an equivalent RLC network determined by the frequency dependent network equivalent(FDNE)*** the proposed method,the observability index and the electrical distance index are used to identify the interface between the middle and the external *** studies based on a modified Hydro-Quebec system are used to verify the effective ness of the proposed method.

关键词： Electrical distance network equivalent subsyn chronous oscillation observability index

Paraffin–CaCl_(2)·6H_(2)O dosage effects on the strength and heat transfer characteristics of cemented tailings backfill

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 60-70页

作者： Hai Li Aibing Jin Shuaijun Chen Yiqing Zhao You ju Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mine University of Science and Technology BeijingBeijing 100083China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China

The challenge of high temperatures in deep mining remains harmful to the health of workers and their production efficiency The addition of phase change materials (PCMs) to filling slurry and the use of the cold storage function of these materials to reduce downhole temperatures is an effective approach to alleviate the aforementioned ***–CaCl_(2)·6H_(2)O composite PCM was prepared in the *** composition,phase change latent heat,thermal conductivity,and cemented tailing backfill (CTB) compressive strength of the new material were *** heat transfer characteristics and endothermic effect of the PCM were simulated using Fluent *** results showed the following:(1) The new paraffin–CaCl_(2)·6H_(2)O composite PCM improved the thermal conductivity of native paraffin while avoiding the water solubility of CaCl_(2)·6H_(2)O.(2) The calculation formula of the thermal conductivity of CaCl_(2)·6H_(2)O combined with paraffin was deduced,and the reasons were explained in principle.(3) The“enthalpy–mass scale model”was applied to calculate the phase change latent heat of nonreactive composite PCMs.(4)The addition of the paraffin–CaCl_(2)·6H_(2)O composite PCM reduced the CTB strength but increased its heat absorption *** research can give a theoretical foundation for the use of heat storage backfill in green mines.

关键词： paraffin–CaCl_(2)·6H_(2)O heat transfer simulation heat calculation phase change material-based backfill latent heat of formula

A stepwise approach to enhancing flotation of low-grade zinnwaldite through the cationic/DL-2-octanol/anionic reagent combinations: Behavior and mechanism analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第6期34卷 881-891页

作者： Zhonghua Xue Yali Feng Haoran Li Jinrong ju Xingquan Du School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In order to alleviate the pressure on the supply of lithium resources, this research proposes the use of binary/ternary collectors with high selectivity and collecting ability to enhance the flotation purification of low-grade zinnwaldite ore. The binary collector is a mixture of dodecylamine polyoxyethylene ether and DL-2-octanol. A binary collector is added first, followed by sodium oleate, known as a ternary collector. Under acidic conditions, the recovery of Li2O in the concentrate was increased by 8.26% with the binary collector and 13.70% with the ternary collector, compared to the dodecylamine polyoxyethylene ether. The binary collector enhanced the dispersibility of the single collector, while co-adsorption strengthened the hydrophobic nature of the zinnwaldite surface. Consequently, zinnwaldite particles,after the application of binary collector, displayed inter-particle flocculation and attachment to bubbles within 60×10^(-9)m compared to other particles. Ternary collector exhibited the capacity to lower critical micelle concentration and surface tension, subsequently inducing a denser and thicker hydrophobic layer through electrostatic forces, hydrophobic interactions, and chemical reactions. The objective of this research is to facilitate the recovery of lithium resources from low-grade ores in order to meet the needs of sustainable development.

关键词： Zinnwaldite Molecular dynamics simulation Flotation Ternary collector Extended DLVO theory

Effectiveness and Safety of Qishen Yiqi Dripping Pill in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention:3-Year Results from a Multicentre Cohort Study

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第10期30卷 877-885页

作者： BAI rui-na GU Feng CHE Qian-zi ZHANG Xuan CAI Ya-jie XI rui-xi ZHAO Yang GUO Ming DONG Guo-ju GAO Zhu-ye FU Chang-geng WANG Pei-li DU Jian-peng ZHANG Da-wu DUAN Wen-hui LI Li-zhi YANG Qiao-ning SHI Da-zhuo Department of Cardiovascular Xiyuan HospitalChina Academy of Chinese Medical SciencesBeijing100091China National Clinical Research Center for Chinese Medicine Cardiology Beijing100091China Department of Evidence-Based Medicine Basic Research Laboratory Institute of Basic Research in Clinical MedicineChina Academy of Chinese Medical SciencesBeijing100700China Department of Traditional Chinese Medicine Beijing Shangdi HospitalBeijing100193China National Medical Products Administration Key Laboratory for Clinical Research and Evaluation of Traditional Chinese MedicineBeijing100091China

Objectives:To evaluate the effectiveness and safety of Qishen Yiqi Dripping Pill(QSYQ)in patients with acute coronary syndrome(ACS)after percutaneous coronary intervention(PCI).Methods:This multicentre prospective cohort study was conducted at 40 centers in *** with ACS after PCI entered either the QSYQ or Western medicine(WM)groups naturally based on whether they had received QSYQ before *** group received QSYQ(0.52 g,3 times a day for 12 months)in addition to *** primary endpoint included cardiac death,non-fatal myocardial infarction,and urgent *** secondary endpoint included rehospitalization due to ACS,heart failure,stroke,and other thrombotic *** of life was assessed by the Seattle Angina Questionnaire(SAQ).Results:A total of 936 patients completed follow-up of the primary endpoint from February 2012 to December ***,487 patients received QSYQ and *** a median follow-up of 566 days(inter quartile range,IQR,517–602),the primary endpoint occurred in 46(9.45%)and 65(14.48%)patients in QSYQ and WM groups respectively[adjusted hazard ratio(HR)0.60,95%confidence interval(CI)0.41–0.90;P=0.013].The secondary endpoint occurred in 61(12.53%)and 74(16.48%)patients in QSYQ and WM groups,respectively(adjusted HR 0.76,95%CI 0.53–1.09;P=0.136).In sensitivity analysis,the results still demonstrated that WM combined with QSYQ reduced the risk of the primary endpoint(HR 0.67,95%CI 0.46–0.98;P=0.039).Moreover,QSYQ improved the disease perception domain of the SAQ(P<0.05).Conclusions:In patients with ACS after PCI,QSYQ combined with WM reduced the incidence of the primary *** findings provide a promising option for managing ACS after PCI and suggest the potential treatment for reducing the risk of primary endpoint included cardiac death,non-fatal myocardial infarction,and urgent revascularization through intermittent administration of QSYQ.(Registration *** CTR-OOC-14005552).

关键词： Qishen Yiqi Dripping Pill acute coronary syndrome percutaneous coronary intervention primary and secondary endpoint

在线全文

学校读者我要写书评

暂无评论

小学班主任如何构建核心班级

家长 2020年第21期 31-31页

作者：鞠瑞甘肃省张掖市甘州区金安苑学校

本文以小学班主任构建核心班级为主线,从小学班主任管理现状出发,具体分析核心班级的重要意义,并针对性地提出相关解决措施,以期为更多小学班主任从事班级建设提供帮助。

关键词：小学班主任核心班级可行路径

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

网络信息化背景下拔尖创新人才培养探究

电子测试 2013年第12S期24卷 272-273页

作者：鞠蕊河海大学公共管理学院 211100

随着知识经济和信息技术的飞速发展,互联网以其不可抵挡的影响力改变着所有人的学习和生活方式,网络信息化应运而生。网络信息化背景下的高校拔尖创新人才培养,必须在培养目标、培养内容、培养方式、培养制度和评价等方面,提高网络科技... 详细信息

随着知识经济和信息技术的飞速发展,互联网以其不可抵挡的影响力改变着所有人的学习和生活方式,网络信息化应运而生。网络信息化背景下的高校拔尖创新人才培养,必须在培养目标、培养内容、培养方式、培养制度和评价等方面,提高网络科技利用率,实现拔尖创新人才培养模式高质量、高效率、高使用率的运行。

关键词：网络信息化拔尖创新人才培养模式

Analytic Formulae for Estimating Motor Proportion of Load Model Under Small Disturbance

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1599-1607页

作者： Ping ju Shiqiu Xia Yuqing Jin Lu Cao School of Electrical and Power Engineering Hohai UniversityNanjing 211100China the East China Branch of the State Grid Corporation of China Shanghai 200120China

In the composite load model(CLM),which is commonly used in China,an equivalent motor and equivalent static load are used to represent all electrical equipment and networks connected to a load *** research has determined typical values of electrical and mechanical parameters for load models of different load types,which improves the basis for load ***,the motor proportion parameter is not the same for different load buses or at different times;therefore,obtaining the actual motor proportion is key to establishing an accurate load *** the existing load modeling method,motor proportion is commonly identified along with other parameters under rare large disturbances;therefore,the value of the motor proportion is fixed by the time when a large disturbance *** this paper,formulae are derived to estimate motor proportion under small disturbances,and these formulae allow direct calculation of motor proportion without using any optimization *** proposed estimation formulae do not rely on any parameters of load model or power system but instead rely only on measurement of the voltage and active power at steady-state points before and after a small *** of universality of small disturbances in power systems,estimating time-varying motor proportion under small disturbances will be helpful for solving the time-varying problem of load ***,the proposed motor proportion estimation formulae are validated by simulations,physical experiments,and field experiments.

关键词： Composite load model load modeling motor proportion parameter estimation

Hierarchical Control Strategy for Load Regulation Based on Stackelberg Game Theory Considering Randomness

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

CSEE Journal of Power and Energy Systems 2024年第3期10卷 929-941页

作者： Tingyu Jiang Ping ju C.Y.Chung Yuzhong Gong College of Energy and Electrical Engineering Hohai UniversityNanjing 211100China Department of Electrical Engineering City University of Hong KongHong Kong CF624China Department of Electrical and Computer Engineering University of SaskatchewanSaskatoonSK S7N 5A9Canada CSEE IEEE

Demand response has been recognized as a valuable functionality of power systems for mitigating power *** paper proposes a hierarchical control strategy among the distribution system operator(DSO),load aggregators(LAs),and thermostatically controlled loads(TCLs);the strategy includes a scheduling layer and an executive layer to provide load *** the scheduling layer,the DSO(leader)offers compensation price(CP)strategies,and the LAs(followers)respond to CP strategies with available regulation power(ARP)*** of the DSO and LAs are modeled according to their behaviors during the load regulation *** game is adopted to capture interactions among the players and leader and to obtain the optimal strategy for each participant to achieve ***,considering inevitable random factors in practice,e.g.,renewable generation and behavior of users,two different stochastic models based on sample average approximation(SAA)and parameter modification are formulated with improved scheduling *** the executive layer,distributed TCLs are triggered based on strategies determined in the scheduling layer.A self-triggering method that does not violate user privacy is presented,where TCLs receive external signals from the LA and independently determine whether to alter their operation *** simulations are performed on the modified IEEE-24 bus system to verify effectiveness of the proposed strategy.

关键词： Demand response hierarchical control load regulation self-triggering method Stackelberg game

Shape optimisation of basin insulator for DC gas insulated switchgear/gas insulated transmission lines based on artificial bee colony algorithm

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

High Voltage 2024年第2期9卷 275-286页

作者： Yi Luo Shiyi Mao ju Tang Zijun Pan Cheng Pan State Key Laboratory of Power Grid Environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhanChina

The surface charge accumulation on the basin insulator is a particular problem in high-voltage direct current(HVDC)gas insulated switchgears(GIS)and gas insulated trans-mission lines(GIL),which restricts the development and application of extra/ultra high-voltage(EHV/UHV)*** surface charge distribution and anti-flashover performance are closely related to the insulator *** obtain the optimal basin insulator,a shape optimisation model based on artificial bee colony algorithm was established,and the minimisation objective functions based on capacitive(initial)electric field distribution and resistive(steady-state)electric field distribution were respectively *** optimisation results of the two objective functions were calculated,and the electric field and charge distribution on the surface of the insulator before and after optimisation were evaluated and compared using the simulation *** results indicated that the optimisation based on the capacitive electric field can significantly inhibit the surface charge accumulation,and the optimised insulator can significantly reduce the surface normal electric field and make the distribution of the tangential electric field more uniform,and the maximum tangential electric field can be reduced by 10%;the optimisation based on resistive electric field can achieve similar results,but requires more computational *** on the results,the‘anti-charge’basin insulator structure suitable for the DC field was given.

关键词： insulator artificial charge