《中国水利》投稿须知

1.稿件字数一般在4000～6000字,文字精练,观点鲜明,可附图表,并配300字以内的中文摘要和关键词。如有可能,请附上英文标题、摘要和关键词。     

利用离线语音库无阻碍学习英文

很多朋友在智能手机上安装有道词典学习英语,总会遇到无法联网的尴尬,其实我们可以利用有道词典的离线语音库解决这一难题。     

Analysis,design,and experimental evaluation of power calculation in digital droop-controlled parallel microgrid inverters

Parallel operation of distributed generation is an important topic for microgrids,which can provide a highly reliable electric supply service and good power quality to end customers when the utility is unavailable.However,there is a well-known limitation:the power sharing accuracy between distributed generators in a parallel operation.Frequency and voltage droop is a well-established control method for improving power sharing performance.In this method,the active and reactive power calculations are used to adjust the frequency and amplitude of the output voltage.This paper describes the digital implementation of a droop method,and analyzes the influence of power calculation on droop method performance.According to the analysis,the performance of droop control in a digital control system is limited by the accuracy and speed of the power calculation method.We propose an improved power calculation method based on p-q theory to improve the performance of the droop control method,and we compare our new method with two traditional power calculation methods.Finally,simulation results and experimental results from a three single-phase 1-kW-inverter system are presented,which validate the performance of our proposed method.     

An empirical molecular docking study of a di-iron binding protein with iron ions

Various molecular docking software packages are available for modeling interactions between small molecules and proteins.However,there have been few reports of modeling the interactions between metal ions and metalloproteins.In this study,the AutoDock package was employed to example docking into a di-iron binding protein,bacterioferritin.Each binding site of this protein was tested for docking with iron ions.Blind docking experiments showed that all docking conformations converged into two clusters,one for internal iron binding in sites within the metalloprotein and the other for external iron binding on the protein surface.Local docking experiments showed that there were significant differences between two internal iron binding sites.Docking at one site gave a reasonable root-mean-square deviation(RMSD) distribution with relatively low binding energy.Analysis of the binding mode quality for this site revealed that more than half of the docking conformations were categorized as having good binding geometry,while no good conformations were found for the other site.Further investigations indicated that coordinating water molecules contributed to the stability of binding geometries.This study provides an empirical approach towards the study of molecular docking in metalloproteins.     

Stochastic computer network with multiple terminals under total accuracy rate

From the viewpoint of service level agreements,data transmission accuracy is one of the critical performances for assessing Internet by service providers and enterprise customers.The stochastic computer network(SCN),in which each edge has several capacities and the accuracy rate,has multiple terminals.This paper is aimed mainly to evaluate the system reliability for an SCN,where system reliability is the probability that the demand can be fulfilled under the total accuracy rate.A minimal capacity vector allows the system to transmit demand to each terminal under the total accuracy rate.This study proposes an efficient algorithm to find all minimal capacity vectors by minimal paths.The system reliability can then be computed in terms of all minimal capacity vectors by the recursive sum of disjoint products(RSDP) algorithm.     

改嫁乌班图上网本焕新春 调教篇

书接上回。千辛万苦在中文界面中安装好了乌班图,临了却发现是个英文版,按新版《三国》里曹操的说法就是：眼睛一眨,老母鸡变鸭。不会装错版本了吧……     

上网本最后的博弈

上网本,英文为“Netbook”,抛开Intel对其冗长的定义,其实它说穿了就是一个尺寸小,便携的低性能笔记本电脑（以下简称“本本”）。它的出现一举填补了2000—3000元档次本本的空白,以低廉的价格引爆了市场。然而风光过后,上网本暴露出来的缺陷,也让它在面对新的竞争对手时力不从心。在超低电压本本和平板电脑的层层重压下,上网本终于感受到了生存的威胁。     

藏文搜索引擎系统中网页自动摘要的研究

给出了藏文搜索引擎中网页自动摘要的基本思路、基本步骤和Web了分词算法,提出了基于句子抽取的Web文摘生成算法.算法中将每个Web句子的权重分解为Web特征词权重和Web句子结构权重,Web句子结构权重充分考虑排版格式和超连接属性.根据权值大小按给定的比例挑选句子,并进行平滑处理,生成文字流畅且具备一定质量的摘要.最后实验分析表明效果较好.     

一种基于HASH函数的EAP认证协议①

随着安全认证技术的发展,网络认证已成为保障网络安全的重要环节。当前被广泛使用的IEEE802．1X是建立在可扩展认证协议（EAP）基础上的一种认证框架。EAP提供了许多认证协议,每个认证协议都有自身的优缺点。有些没有提供用户名的保护,有些没有提供双向认证;有些部署较困难等。针对上述缺陷,提出了一种基于哈希函数的认证协议。阐述了该协议的具体认证过程,并对其进行了安全性分析,最后与当前一些认证协议作了比较。