中型山区河流水电站下游的鱼类生态需水量计算

为更好地对河流水电开发后的鱼类进行保护,探讨中型山区河流水电站下游的鱼类生态需水量计算.参照大型河流鱼类水力生境参数标准,根据中型山区河流的特点,得到中型山区河流鱼类水力生境参数的参考标准.选取有代表性的四川中型山区河流杂谷脑河进行鱼类生境原型观测,原型观测结果证实了该参考标准能够满足杂谷脑河鱼类对生境的实际需求.基于所得到的参考标准,应用生态水力学法对杂谷脑河红叶二级、理县以及甘堡3座电站减水河段的鱼类生态需水量进行计算分析,得到3座电站的生态需水量推荐值.通过分析可知,所得到的生态需水量推荐值占年均天然流量以及设计引用流量的比例都不高,在3座电站的运行实践中,具有可操作性.     

Node trust evaluation in mobile ad hoc networks based on multi-dimensional fuzzy and Markov SCGM(1, 1) model

Due to the nature of distribution and self-organization, mobile ad hoc networks rely on cooperation between nodes to transfer information. One of the key factors to ensure high communication quality is an efficient assessment scheme for risks and trust of choosing next potential cooperative nodes. Trust model, an abstract psychological cognitive process, is one of the most complex concepts in social relationships, involving factors such as assumptions, expectations and behaviors. All of the above make it difficult to quantify and forecast trust accurately. In this paper, based on the theories of fuzzy recognition with feedback, SCGM(1, 1) model and Markov chain, we present a pattern of prediction making. The analysis and experimental computation show that this scheme is efficient in trust prediction for ad hoc networks.     

Buckling of carbon fiber composite pyramidal truss core sandwich columns

This paper deals with the theoretical prediction of global buckling loads for carbon fiber composite pyramidal truss core sandwich columns. Different from thin plate structures, transverse shear effect can not be neglected for sandwich structures. In addition, the attributes of the laminated face sheets are considered in the present paper. A zig-zag displacement approximation is made. Based on the principle of minimum potential energy, equilibrium equations and boundary conditions are derived via the variational method. The critical buckling loads under various boundary conditions are presented. In order to validate the reasonableness of the equivalent-core method, the strain energies stored in the actual discrete truss members and the equivalent continuous homogenous core layer are calculated respectively and compared, and a good agreement is obtained. The proposed analytical method is verified by comparing with the published theoretical predictions and experimental results.     

基于消除地方高校成长上限基模的实证研究——以江西M学校为例

本文基于系统动力学反馈基模分析方法,在分析江西地方高校发展的成长上限基模和对策基模的基础上进行实证研究,引入相关数据,构建消除成长上限基模的顶点赋权模型,并提出综合对策思考。     

水性木器装修清漆的研制

以水性聚氨酯分散体与丙烯酸乳液及其混合液为成膜物 ,选用几种合适的助剂 ,研制出性能价格比良好的水性木器装修清漆。     

对应用投资项目财务评价指标的探讨

投资项目财务效果评价指标，按决策目的可分为绝对效果评价指标和相对效果评价指标两大类；按是否考虑资金时间价值可分为静态评价指标和动态评价指标两大类。本文将按后一种分类对项目评价中使用的各种指标的应用作以下的探讨。     

基于Internet的空分设备远程监视与故障诊断专家系统的研究

简介了远程监视与故障诊断专家系统在国内空分设备中应用的实际意义，着重分析了大型空分设备远程监视与故障诊断专家系统中远程监视模块和故障诊断模块的开发。     

Solaris下综合教务系统的管理和维护

对于Solaris下综合教务系统的管理和维护,本文从系统的优化调整,备份、恢复策略,系统安全保护措施等三个方面进行了探讨。     

Analysis of the critical heat flux in round vertical tubes under low pressure and flow oscillation conditions. Applications of artificial neural network

Artificial neural networks (ANNs) for predicting critical heat flux (CHF) under low pressure and oscillation conditions have been trained successfully for either natural circulation or forced circulation (FC) in the present study. The input parameters of the ANN are pressure, mean mass flow rate, relative amplitude, inlet subcooling, oscillation period and the ratio of the heated length to the diameter of the tube, L/D. The output is a nondimensionalized factor F, which expresses the relative CHF under oscillation conditions. Based on the trained ANN, the influences of principal parameters on F for FC were analyzed. The parametric trends of the CHF under oscillation obtained by the trained ANN are as follows: the effects of pressure below 500 kPa are complex due to the influence of other parameters. F will increase with increasing mean mass flow rate under any conditions, and will decrease generally with an increase in relative amplitude. F will decrease initially and then increase with increasing inlet subcooling. The influence curves of mean mass flow rate on F will be almost the same when the period is shorter than 5.0 s or longer than 15 s. The influence of L/D will be negligible if L/D>200. It is found that the minimum number of neurons in the hidden layer is a product of the number of neurons in the input layer and in the output layer.     

基于判断矩阵的软件评价指标权重分配方法

本文主要讨论判断矩阵的性质和特点，阐明了利用判断矩阵为软件质量评价指标分配权重的原理，对一致性较差的判断矩阵给出了修正方法，最后给出了权重分配方法。