开封市污水资源量计算方法研究

污水资源利用是解决区域水资源短缺问题的有效途径。对污水资源量计算方法进行研究,有助于准确、定量地评估污水资源可利用量。以开封市为例,运用《室外排水设计规范》、万元产值耗水量、排污系数法、平均年型等计算方法,得出2015年开封市污水资源可利用总量将达到21 346.8万m3,可部分满足城市生活与工业用水需求,一定程度上缓解开封市水资源的供需矛盾。     

大岗山地下厂房洞群施工开挖围岩稳定性分析

为分析大岗山水电站地下厂房洞室群施工开挖过程中围岩的稳定性状况,采用多元回归分析方法反演了厂区初始地应力场,提出了厂区初始地应力的分布函数;根据建立的地下厂房三维数值计算模型,获得洞室开挖后围岩位移场、应力场和塑性区的变化规律。计算结果表明:大岗山地下厂房洞室群开挖后围岩整体是稳定的,洞周分布的软弱岩脉是影响围岩稳定的关键因素,在地下厂房施工过程中,必须对软弱岩脉和开挖暴露的破碎带进行超前注浆加固处理。计算成果有效指导了工程的设计与施工。     

A hybrid DEM/CFD approach for solid-liquid flows简

A hybrid scheme coupling the discrete element method(DEM)with the computational fluid dynamics(CFD)is developed to model solid-liquid flows.Instead of solving the pressure Poisson equation,we use the compressible volume-averaged continuity and momentum equations with an isothermal stiff equation of state for the liquid phase in our CFD scheme.The motion of the solid phase is obtained by using the DEM,in which the particle-particle and particle-wall interactions are modelled by using the theoretical contact mechanics.The two phases are coupled through the Newton’s third law of motion.To verify the proposed method,the sedimentation of a single spherical particle is simulated in water,and the results are compared with experimental results reported in the literature.In addition,the drafting,kissing,and tumbling(DKT)phenomenon between two particles in a liquid is modelled and reasonable results are obtained.Finally,the numerical simulation of the density-driven segregation of a binary particulate suspension involving 10 000 particles in a closed container is conducted to show that the presented method is potentially powerful to simulate real particulate flows with large number of moving particles.     

河渠水面线推求方向的可行性研究

河渠水面线的推求,首先必须确定推求方向,因为虽然从理论上可从上游或下游断面开始递推,但实际上都可能遇到无法推求的情况.构建的规则河渠水面线推求方向可行性分析方法,首先分析水面线计算式上、下断面能量函数曲线的特性,研究计算河段长度、河道底坡对其的影响;然后探讨上、下断面的能量函数曲线相对位置关系,从而探究无法推求的原因及求解的规律性,并以实例进行分析.研究结果表明,由下游向上游推求等截面缓坡、临界坡河段及收缩河段,或由上游向下游推求等截面陡坡、临界坡河道及扩散河段,总能找到可行解或通过缩短计算河段长度找到可行解;而由上游往下游推求等截面缓坡河段、收缩河段,或由下游向上游推求等截面陡坡河段、扩散河段时,则存在无解区域,且无解区域发生在临界流态的某一邻域内,邻域左右半径不一定相等;此外,河段长度愈长,坡度愈陡,邻域半径愈大.     

高面膜堆石坝发展的需求与关键技术——高面膜堆石坝关键技术(一)

面膜堆石坝是指上游坝面用土工膜防渗的堆石坝。综述了面膜堆石坝半个世纪以来的发展状况,分析了该坝型的特点及该坝型技术在我国的使用现状与需求:面膜防渗结构具有渗透性低微、差异变形适应性强、施工简捷、工期短、造价低等特点;由于国外专利保护等原因,面膜堆石坝技术未能如面板堆石坝和碾压混凝土坝那样广泛交流与推广,自国外第一座面膜堆石坝建成以来,国内尚未建成一座高面膜堆石坝,而我国水电清洁能源的需求、许多深覆盖层坝址与黏土防渗体取土受到环境生态制约的状况,需要高面膜堆石坝发挥其作用,相应的设计分析技术需要较系统深入的研究梳理和集成。概述了该坝型关键技术研究的初步成果,包括高面膜堆石坝的周边夹具效应与设计方法、面膜双向拉伸分析方法、数值精细模拟方法、非散粒体面膜垫层技术、膜顶胀损缺性状量化分析方法。     

The rebound effect: An evolutionary perspective

The rebound effect presents a major flaw in to energy conservation policies that aim to reduce energy consumption through energy efficiency development. Economics and energy related disciplines have thus far developed tools to measure such a phenomenon. This paper attempts to explain this seeming paradox using a thermodynamic-evolutionary theoretical framework in addition to the traditional economic approach. We here propose that evolutionary systems, such as biological or even economic systems, may rearrange themselves in a more complex fashion under the pressure of an increasing flux of energy, driven by the higher conversion rate of greater efficiency. Higher complexity, due to a greater energy density rate, counteracts the positive effects of energy efficiency. We investigated this hypothesis in the context of the road freight transport system and the productive structure. The qualitative analysis in this paper, further substantiated by figures, provides a link between the dynamics of production patterns and the effect of efficiency in the light of the macro-economic effects of increased energy demand. The analysis departs from a rigorous investigation of the actual energy efficiency evolution in the road freight transport system to develop through a survey of the subsequent worldwide economic revolution in the production system. It is then shown how outsourcing, the key feature of globalization, can be identified as the main source of traffic density growth. Finally, four paradigms are used to stress how the shift in the production system must be considered a leap in structural complexity that consequently serves to increase the frequency of components’ interactions.     

技术变迁:民族地区旅游产业升级优化的途径

在分析民族地区旅游产业升级优化的必要性和面临的现实问题基础上，应用经济学技术变迁理论，分析和指出技术变迁是民族地区旅游产业升级和优化的必由之路．并运用技术变迁模型分析了民族地区旅游产业升级优化的技术创新途径。提出了相应的对策措施。     

提升县域支柱企业核心竞争力的途径

我们认为提升县域支柱企业核心竞争力应从以下几方面做起:其一,制定提升核心竞争力的发展战略,提高决策水平;其二,整合企业重要资源,强化创新能力;其三,完善信息系统,增强应变能力;其四,建立学习型组织,提高学习能力。     

加强我院教工党支部工作活力的有效途径研究

高校党支部是高校党组织最基层的组织单元,是党的全部工作和战斗力的基础。为了进一步增强我院教工党支部工作活力,必须从改进党支部的设置、提高党支部书记的素质和能力入手,创新党员教育管理形式和党组织活动方式,完善党支部的工作制度建设,建立健全党支部工作评估的科学体系。     

中国农村现代化问题探微

本从建国以来我国农村现代化的三次思潮出发，提出当前阻碍现代化进程的“三农”问题，探讨实现农村现代化的基本途径，并分析我国农村现代化的现实条件，旨在坚定人们对农村经济和社会发展的信心。