基于SD模型的渭河流域关中地区水资源调度系统优化资

流域水资源调度系统是一个具有复杂结构的开放巨系统,具有高阶次、多变量、多回路和强非线性的反馈结构,系统行为往往具有反直观的特性。运用系统动力学理论与方法建立流域水资源调度系统模型较传统的数学模型更能充分刻画系统的非线性结构和动态特征。本文以渭河流域关中地区为例,在深入分析系统内外因素及其反馈关系的基础上,运用系统动力学(SD)构建渭河流域关中地区水资源调度系统模型,以模型为基础,建立了渭河流域水资源调度的5种方案,即规划调度方案、经济优先发展方案、生态保护调度方案、需水量调度方案和缺水量动态调度方案,并采用Vensim PLE软件进行系统仿真,获取2020年末5种调度方案的仿真结果。从经济效益、社会效益和生态效益3方面出发选取6组评价指标对各方案的仿真结果进行灰色系统综合评价,结果显示:缺水量动态调度方案是渭河流域关中地区水资源调度的最佳方案(R=0.589),进而提出对现有水资源规划调度方案的优化措施。     

除灰系统布置优化专题论述

针对五常生物质发电厂工程灰渣全部综合利用,结合秸秆电厂循环流化床锅炉特性,分别对机械输方案及气力输送方案进行技术经济比较,确定最佳输送方案,在确定输送方案的同时,对除灰系统总体布置进行优化,使除灰系统方案更加合理、经济,满足业主对除灰系统设计的要求。     

混合式通风系统公共风路风量优化调节方案研究

针对某煤矿西风井贯通后,西风井与副井进风相互影响造成通风系统失衡的问题,对矿井现有通风系统进行了阻力测定与计算机网络模拟,提出技能改造的三种优化方案。利用网络结算软件对三种方案进行模拟优化,从经济、技术、安全稳定三个方面对优化方案进行比较,确定方案三为最优方案。     

LTE FDD室内分布系统关键技术探讨

探讨LTE FDD室内分布系统的多种建设方案并对各种方案的优缺点进行了对比分析,最终通过测试分析给出了不同建设方案的应用建议,该研究结论对LTE FDD室内分布系统的设计有一定的参考意义。     

智能变电站的几种计量系统方案设计

分析了智能变电站对传统计量系统的影响,提出了智能变电站计量系统的几种设计方案.通过对三种方案特点的分析对各方案的适用性给出建议.     

东科水电站引水系统布置选择分析

东科水电站引水系统布置分析时,以上阶段研究推荐的坝、厂址为基础进行方案比较,对跨水子沟进行内、外线方案比较,在外线方案的基础上又进行跨沟与绕沟的比较,以确定东科水电站引水系统布置方案,便于施工前期工作的开展。     

通风系统仿真研究与白龙煤矿应用

通过对白龙煤矿通风系统的详细普查,利用矿井通风仿真系统（MVSS3.1）,构建了白龙煤矿通风仿真系统。针对白龙煤矿的通风系统及下一步采掘计划,经过对通风系统的分析研究,发现通风系统中存在的问题,对系统中不合理的巷道配置提出了优化改进方案。通过计算机进行优化方案仿真模拟,并将仿真结果与实际进行对比,确定了最终优化方案,为白龙煤矿通风系统优化改造提供了理论依据。     

酸碱贮存区域卸酸碱系统的技术方案研究

本文介绍了核电站卸酸碱系统的典型方案并分析了该系统存在的主要问题,同时,对常规火电站各种卸酸碱系统方案及设备应用做了详细分析和总结,提出两个可行的改进方案,旨在优化核电除盐水生产用卸酸碱系统设计,提高操作人员人身安全保障和酸碱可利用率。     

基于Web服务和SOA的电子政务建设方案研讨

通过具体案例分析,提出采用Web服务和SOA架构建设电子政务系统,对Web服务概念和SOA概念作了详细介绍,最后对电子政务系统建设方案进行探讨,并指出这种方案的优点。     

五种嵌入式Internet接入方案的研究分析

本文介绍了五种主流嵌入式系统Internet接入方案,从关键的TCP/IP协议处理方式入手分析了五种接入方案软硬件的组成和功能,并以各自对软硬件的依赖程度及实现成本,详细地分析了这五种接入方案的优点和缺点,最后给出嵌入式系统Internet接入方案的选择建议以供参考。     

校企合作中高校如何避免人才流失

随着社会的发展,知识和经济结合得越来越紧密。象征实现学术抱负和追求经济效益的高度统一体的多种校企合作模式就是两者紧密结合的产物。高校和企业通过校企合作达到各自的目标,但是日益严重的高校人才流失阻止了校企的进一步合作,并给高校带来了严重的损失。本文分析了人才流失给高校带来的损失,高校人才的去向,高校人才流向企业的原因,并提出了两种解决方案。要达到在一个长时间段内保持低水平的人才流失率,高校需双管齐下。     

Serendipity: Towards a taxonomy and a theory

Serendipity, the notion of researchers making unexpected and beneficial discoveries, has played an important role in debates about the feasibility and desirability of targeting public R&D investments. The purpose of this paper is to show that serendipity can come in different forms and come about in a variety of ways. The archives of Robert K Merton, who introduced the term to the social sciences, were used as a starting point for gathering literature and examples. I identify four types of serendipity (Walpolian, Mertonian, Bushian, Stephanian) together with four mechanisms of serendipity (Theory-led, Observer-led, Error-borne, Network-emergent). I also discuss implications of the different types and mechanisms for theory and policy.     

植物学家和人文主义者胡先骕

本文概述了植物分类学家胡先骕在发现植物新种水杉中的贡献;他在上世纪五十年代批判李森科,倡导摩尔根遗传学说的动因,及其科学、人文背景;最后,作为新文化运动中《学衡》派主力和唯一的科学家,本文对他的新人文主义思想做一简介和评述。     

Making a hydrophoretic focuser tunable using a diaphragm

Microfluidic diagnostic devices often require handling particles or cells with different sizes. In this investigation, a tunable hydrophoretic device was developed which consists of a polydimethylsiloxane (PDMS) slab with hydrophoretic channel, a PDMS diaphragm with pressure channel, and a glass slide. The height of the hydrophoretic channel can be tuned simply and reliably by deforming the elastomeric diaphragm with pressure applied on the pressure channel. This operation allows the device to have a large operating range where different particles and complex biological samples can be processed. The focusing performance of this device was tested using blood cells that varied in shape and size. The hydrophoretic channel had a large cross section which enabled a throughput capability for cell focusing of ∼15 000 cells s⁻¹, which was more than the conventional hydrophoretic focusing and dielectrophoresis (DEP)-active hydrophoretic methods. This tunable hydrophoretic focuser can potentially be integrated into advanced lab-on-a-chip bioanalysis devices.     

抓好一项活动 培育一种品质 成就一生精彩

我们学校全体师生齐心协力,锐意进取,从学生最喜欢的活动抓起,从教育最基本的积累开始,关注细节,培育做人做事的品质,努力为学生的一生精彩奠基,取得了积极的成效。     

From a single network to a network of networks

Network science has atracted much atention in recent years due to its interdisciplinary applications. We witnessed the revolution of network science in 1998 and 1999 started with small-world and scale-free networks having now thousands of high-proile publications, and it seems that since 2010 studies of‘network of networks'(NON), sometimes called multilayer networks or multiplex, have atracted more and more atention. he analytic framework for NON yields a novel percolation law for n interdependent networks that shows that percolation theory of single networks studied extensively in physics and mathematics in the last 50 years is a speciic limit of the rich and very diferent general case of n coupled networks. Since then, properties and dynamics of interdependent and interconnected networks have been studied extensively, and scientists are inding many interesting results and discovering many surprising phenomena. Because most natural and engineered systems are composed of multiple subsystems and layers of connectivity, it is important to consider these features in order to improve our understanding of such complex systems. Now the study of NON has become one of the important directions in network science.In this paper, we review recent studies on the new emerging area—NON. Due to the fast growth of this ield, there are many deinitions of diferent types of NON, such as interdependent networks,interconnected networks, multilayered networks, multiplex networks and many others. here exist many datasets that can be represented as NON, such as network of diferent transportation networks including light networks, railway networks and road networks, network of ecological networks including species interacting networks and food webs, network of biological networks including gene regulation network,metabolic network and protein–protein interacting network, network of social networks and so on. Among them, many interdependent networks including critical infrastructures are embedded in space, introducing spatial constraints. hus, we also review the progress on study of spatially embedded networks. As a result of spatial constraints, such interdependent networks exhibit extreme vulnerabilities compared with their non-embedded counterparts. Such studies help us to understand, realize and hopefully mitigate the increasing risk in NON.