地震属性对云质岩储层识别的探讨

由于油气预探阶段钻井相对较少,地震属性分析技术能弥补此阶段钻、测井资料不足的劣势,其在储集性能评价和含油气性评价中起了重要作用。本文应用地震属性分析技术对新疆某地区风城组云质岩储层进行识别,并通过已钻井进行对比分析,从而确定研究工作的可靠性,对该地区储层预测工作具有指导意义和应用价值。     

370 m跨径X形提篮拱结构有限元模拟研究

渝黔铁路是国家“八纵八横铁路网”中“包柳铁路大通道”的重要组成部分.以渝黔铁路线中X形提篮拱桥为依托工程,为确保施工工程质量与安全,采用Midas/Civil2010有限元软件对该拱桥成桥后主拱圈应力、运营阶段稳定性与位移验算等进行了计算和分析,结果表明该提篮拱桥拱脚处最大压应力为14 MPa满足混凝土规范要求设计值,结构运营阶段稳定系数为32.2,满足现行规范限值,结构在横纵向自振周期分别为1.473 s与1.389 s均满足规范限值.     

最短路问题在旅游线路优化中的应用

本文利用Floyd算法探究了最短路问题,经过Matlab实现后将其应用到旅游线路优化设计中。选取了甘肃及周边地区13个旅游景点,求得从任意景点出发到任意目的景点的最短路,以及途中必须给定两个景点的最短路问题。     

江西经济发展走势对运输需求的分析与预测

区域经济的发展是运输需求的源泉。新世纪以来,江西经济进入了持续稳定发展的快车道,极大地促进了运输需求的持续增长,运输线路长度不断延长,全社会运输量不断增加。随着江西经济社会快速发展,城镇化进程的加快,资源环境约束压力的加大,运输需求结构提升,对运输需求提出了更高的要求,运输需求多样化、个性化、机动化、快速化和网络化的趋势更加显著。     

Weighted progressive interpolation of Loop subdivision surfaces

This paper proposes a weighted progressive method for constructing a Loop subdivision surface interpolating a given mesh. The convergent rate of the weighted progressive interpolation can be controlled by adjusting the weight of the iteration. For different weights in the available range, the limit meshes are the same as that of the reverse solution by directly solving a linear system. The theoretical value for the optimal weight is given based on the smallest eigenvalue of the collocation matrix. An appropriate value of the weight is assigned based on both theoretical analysis and numerical experiments.     

微电网中光伏并网发电系统的建模仿真

微电网技术的发展能有效地解决分布式发电的接入问题,有利于新能源的开发.太阳能作为最具有利用价值的清洁能源之一,并网光伏发电系统的应用前景越来越广阔.通过利用Mat-lab\Simulink软件,开发出了适用于工程计算的光伏电池模型,基于扰动观察法建立了最大功率跟踪模型,结合空间矢量调制(SVPWM)算法设计出了电压外环-电流内环双环控制结构的逆变器并网控制策略,在此基础上搭建了完整的光伏并网发电系统运行与控制模型.仿真结果表明建立的模型能较好的反映三相光伏并网系统运行特性,为微电网的进一步研究提供了基础.     

云计算环境下基于密文策略的权重属性加密方案

在综合分析现有基于密文策略属性加密方案的基础上,针对现有基于密文策略属性加密方案较少考虑属性权重的现状,将权重的概念引入到基于密文策略的属性加密方案中,提出了基于密文策略的权重属性加密方案,证明了在选择权重属性集模型下安全性。并将此方案引入到云计算环境下,给出了系统级的基于密文策略的权重属性加密方案。分析表明,基于密文策略权重属性的加密方案相比现有方案更适用于云计算环境。     

Stochastic formulation of particle kinetics in wall-bounded two-phase flows

This paper presents a generalized framework of stochastic modeling for particle kinetics in wall-bounded flow. We modified a reflected Brownian motion process and straightforwardly obtained a Kramers equation for particle probability density function (PDF). After the wall effects were accounted for as a drift from zero in the mean displacement and suppression in the diffusivity of a particle, an analytical solution was worked out for PDF. Three distinguishable mechanisms were identified to affect the profile of particle probability distribution: external forces, turbophoresis effect, and wall-drift effect. The proposed formulation covers the Huang et al. (2009) model of a wall that produces electrostatic repulsion force and van der Waals force, as well as Monte-Carlo solutions for the Peter and Barenbrug (2002) model under a variety of relaxation times. Moreover, it successfully reproduces the two patterns of particle concentration profiles observed in experiments of sediment-laden open-channel flows. The strength of the wall-drift effect was found to be connected with the interaction frequency between particle and wall. Further exploration of the relationship among flow turbulence, particle inertia, and particle concentration is worthwhile.     

A miniature liquid helium temperature JT cryocooler for space application

Along with the development of space science and technology,miniature liquid helium temperature long life cryocooler is a focus subject in cryogenic study.Since it is the precondition of space detection researches,institutions of space in many countries do the research on it.In this article,we designed a compound cooling system.A three-stage high frequency thermal coupled pulse tube cryocooler was used to precool a Joule-Thomson(JT)cryocooler.This system has no moving parts at low temperatures and is hence suitable for space operation.Liquid helium temperature was successfully achieved in both open loop and closed cycle experiments.In the closed cycle experiment,when 473 W electric power was inputted,the cooling system reached a no-load temperature of 4.4 K,and a cooling capacity of 11.6 mW was provided at 4.54 K.It is the first miniature liquid helium temperature JT cryocooler in China and the research achievement paves a way for the space application of ultra-long wave infrared detection and THz technologies.