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结构动力响应数值分析积分步长的一种简单确定方法

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福建建筑 2002年第1期 20-21页

作者：徐玉野华侨大学土木系 362011

本文首先介绍了数值分析方法的基本思想 ,然后参照 Dunkerley's公式 ,提出了一种用于确定结构动力响应数值分析时间步长的方法。

关键词：结构动力响应数值方法时间步长稳定性

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拋物型方程高精度格式稳定性的证明

滨州学院学报 1991年第4期12卷 62-63页

作者：张天德山东工业大学

在文献[1]中对的差分格式已做了综合介绍,但对三层七点显式只给出了一个四阶格式,本文是在[2]中结论的基础上。

关键词：差分格式方法类综合介绍空间步长显格式时间步长稳定性分析传播矩阵充分必要条件二七

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一种改进的活动轮廓线最优化算法

中国集体经济 2012年第3S期 104-105页

作者：童磊三峡大学信息技术中心

Kass活动轮廓曲线传统最优化算法的数字实现中涉及到时间步长的选取。时间步长选取较短,避免了曲线收敛过程中的震荡问题,但增加了收敛时间;时间步长选取较长,又导致震荡问题的产生。文章提出一种变时间步长的方法,使时间步长在优化的... 详细信息

Kass活动轮廓曲线传统最优化算法的数字实现中涉及到时间步长的选取。时间步长选取较短,避免了曲线收敛过程中的震荡问题,但增加了收敛时间;时间步长选取较长,又导致震荡问题的产生。文章提出一种变时间步长的方法,使时间步长在优化的过程中从大到小变化,较好地解决了固定时间步长收敛时间和震荡的问题,实验结果表明了该方法的有效性。

关键词：活动轮廓线最优化算法时间步长

Simulating the Performance of Solar Water Heating Systems

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Journal of Energy and Power Engineering 2014年第4期8卷 636-645页

作者： Pablo A. Lisboa Manoei A. Fonseca-Costa CEPEL Electricity Power Research Center Rio de Janeiro 21941911 Brazil Mechanical Engineering Department University of the State of Rio de Janeiro Rio de Janeiro 20940200 Brazil

This paper presents a software for simulating the thermal performance of solar water heating systems. The implemented model computes the energy balance in the hot water storage tank in each time step along a simulation interval. Its input data are values from a typical meteorological year of a chosen location and the hot water load. The system components are the hot water storage tank and the solar collector. Firstly, the validation of the model is presented and then four solar water heating systems are simulated in four different cities along one year. The storage tank water hourly temperatures were obtained for a typical meteorological year and those values were compared with the values obtained by the widespread TRNSYS simulation software. The results obtained from this comparison were satisfactory.

关键词：太阳能热水系统热性能模拟典型气象年太阳能集热器软件计算时间步长能量平衡

Correlation Analysis of Gridding of Earthquakes in Datong and Its Surrounding Areas and Implication for Earthquake Prediction

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Earthquake Research in China 2012年第3期26卷 391-398页

作者： Sha Haijun Liu Dongying Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China

On the basis of the earthquake ( M_L ≥3. 0 ) catalog in North China from 1970 to 2009,the pattern of temporal and spatial distribution of medium-small earthquakes in Datong and its surrounding areas is studied by correlation analysis with a focus on its anomaly before moderate and strong earthquakes. With different spatial scales,temporal scales and time steps, the spatial distribution of earthquakes is converted to a sequence, then the correlation coefficients between the spatial distribution of medium-small earthquakes in a long-term and a longer time are calculated for the analysis of anomalies before moderate and strong earthquakes. In the study region center on the epicenter of the 1989 Datong-Yanggao earthquake ( M_S 5. 9 ) within a radius of less than 0. 8°,with the time length of 3600 days,the longer time length of 3700 days,and the time step of 100 days, the correlation coefficient from 1980 to 2009 is steady between 0. 94 and 1. 00,but there were anomalies with values less than 0. 94 in the 2 years before the 1989 Datong-Yanggao earthquake ( M_S 5. 9 ) , the 1991 Datong earthquake ( M_S 5. 8 ) and 1999 Hunyuan earthquake ( M_S 5. 6 ) , which indicates the spatial distribution of a medium-small earthquake is very different from steady background seismicity. The implication for earthquake prediction from the anomaly of the correlation coefficient is also discussed with the three conclusions: ( 1 ) Before moderate and strong earthquakes in Datong and its surrounding areas,the obvious change of spatial distribution patterns of medium-small earthquake can be a kind of seismic precursor of the 2-year time scale for the prediction of an earthquake's time. ( 2 ) As the study region is restricted within a radius of less than 0. 8°,the result of correlation analysis is also good for the prediction of an earthquake's location. ( 3 ) The method of correlation analysis in this paper helps recognize the anomaly of spatial distribution of medium-small earthquake.

关键词：相关性分析地震预报大同地震周边地区空间分布模式时间步长网格相关系数

FPGA-Based Real-Time Simulation of Modular Multilevel Converter HVDC Systems

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Journal of Energy and Power Engineering 2012年第7期6卷 1119-1125页

作者： Luc-André Grégoire Jean Bélanger Wei Li Opal-RT Technologies Montreal H3K 1 G6 Canada

AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for HIL (hardware in the loop) simulators required for control, protection design and testing due to the large number of cells that must be simulated individually using very small time steps. This paper demonstrates the advantages of using a very small time step to simulate a MMC topology. The MMC is implemented on FPGA (fiel-programmable gate array) to simulate fast transient with a time step of 250 ns. The AC network and HVDC bus is simulated on the PC, with a slower time step of 10 us to 20 us. The simulator architecture and the components simulated on the FPGA and on the PC will be discussed, as well as the method allowing the interconnection of this slow and fast system.

关键词：高压直流输电系统 FPGA 多电平变流器模块化实时仿真多电平变换器时间步长能量转换系统

快速和稳定的求解非线性随机微分方程的数值方法

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自然杂志 1991年第11期14卷 875-875页

作者：包景东北京气象学院

目前已建立了3种数值算法,用以求解如下的非线性随机微分方程: (?)=f、x)+g(x)ξ(t), 〈ξ(t)〉=0,〈ξ(t)ξ(t′)〉=δ(t-t′)。

关键词：随机微分方程数值方法数值算法龙格-库塔方法正方案时间步长随机变量扩散过程 Muller Landau

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分子模拟的原理及方法概述

科技信息 2009年第19期 99-99页

作者：马学军沈阳理工大学理学院辽宁沈阳110034

分子模拟原理是根据具体条件确定合适的系综、边界条件、初始条件,导出每个原子运动的加速度,进而得到体系中每个粒子的速度和位置;再设置一定的时间步长,得到每个粒子的位置和速度,直至得到体系的发展变化过程。

关键词：模拟系综时间步长限差分法

Erratum to:Influence of the time-step on the production of free nucleons and pions from heavy-ion collisions around 1 GeV/nucleon [Sci.China-Phys.Mech.Astron.59,122011(2016)]

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Science China(Physics,Mechanics & Astronomy) 2017年第2期60卷 92-92页

作者： LiYan Zou Miao Li ChenChen Guo YongJia Wang QingFeng Li Ling Liu School of Science Huzhou University College of Physics Science and Technology Shenyang Normal University Shanghai Institute of Applied Physics Chinese Academy of Sciences Institute of Modern Physics Chinese Academy of Sciences

In the References of the original publication[1]of this paper,the authors of ref.[26]should be'S.A.Bass,et al.(UrQMD Collaboration)',the authors of ref.[27]should be'M.Ble-icher,et al.(UrQMD Collaboration)'.The author... 详细信息

关键词：自由核子重离子碰撞时间步长介子生产科技伏特电子