基于维纳过程的维修决策和备件库存联合优化

为了降低设备运营总成本,充分发挥视情维修的优势,开展了设备的视情维修决策与备件库存量的联合优化研究。首先,采用Wiener过程建立了退化模型,估计了设备退化参数和剩余寿命;以此为基础,为充分利用剩余寿命的信息价值,引入预约备件的概念,选用遗传算法和蒙特卡罗相结合的方法,建立了以库存参数、预防性检测阈值和预约备件剩余寿命阈值为变量,以部件平均费用率最小为目标的维修与备件的联合优化仿真模型;最后,通过实例比较分析,表明联合优化方法大大地降低了维修和备件总成本,验证了方法的可行性和有效性。     

低渗透油藏井间储量动用状况分析新方法

油藏启动压力梯度对油藏的储层动用有着很大的影响,启动压力梯度越大储层越难动用。从低渗透油藏流体
渗流机理上出发,采用现场早期束缚水条件下单相渗流的生产动态数据及试井解释资料,利用试井方法求得研究区的
启动压力梯度,并建立启动压力梯度与渗透率的关系。分析典型反九点井组内注水井与采油井井间的驱动压力梯度
变化特点,据此确定井间储层物性与储量动用关系。通过对比实际储层的渗透率值与所得到的储层流体启动所需渗
透率值的大小,从而判断储层内流体是否流动。该方法采用定量分析低渗透油藏井间储量动用状况,为同类油藏确定
井间剩余油分布提供了参考。     

Synthesis of kalsilite from microcline powder by an alkali-hydrothermal process

The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline powder in a KOH solution. The microcline powder, rich in potassium, aluminum, and silicon, was collected from Mountain Changling in Northwestern China. The effects of temperature, time, and KOH concentration on the decomposition of microcline were investigated. The kalsilite and intermediate products were characterized by means of wet chemistry analysis, X-ray Diffraction (XRD), infrared spectrometry (IR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), 27Al MAS NMR, and scanning electron microscope (SEM). With increasing temperature, the microcline powder transforms into a metastable KAlSiO₄ polymorph before transforming further into pure kalsilite. A mixture of both kalsilite and metastable KAlSiO₄ polymorph is obtained when the hydrothermal reaction is carried out within 2 h; but after 2 h, kalsilite is the predominant product. The concentration of KOH, which needs to be larger than 4.3 M, is an important parameter influencing the synthesis of kalsilite.     

刚性1,2,4,5-四对甲苯基苯的晶体结构

合成了未引入功能基团的四取代苯类主体分子刚性1,2,4,5-四对甲苯基苯,并用X射线单晶衍射法解析了其晶体结构.晶体属单斜晶系,P1空间群, a=1.0033(6)nm, b=1.1200(7)nm, c=1.1644(7)nm, α=74.63(3)°, β=97.82(2)°, γ=74.98(3)°, V=1.2160(1)nm3, Z=2, Mr=438.58, Dc=1.198g·cm-3, μ(MoKα)=0.067mm-1, F(000)=468,对6109个独立衍射点的最终偏离因子R=0.0580.化合物分子没有对称性,4个对甲基苯环与中心苯环所成二面角分别为49.0°,-40.2°,-43.7°和52.9°.用B3LYP/6-31G**方法对该化合物分子进行了计算,结果表明优化的刚性四对甲苯基苯分子具有C2对称性     

物价收费管理信息系统的设计与实现

使用Delphi 6.0作为前端开发工具,选择InterBase或Access作为后端数据库,设计一个物价收费管理信息系统,该系统由收费许可证管理系统、收费年审统计系统和收费目录及文件查询系统三个子系统组成.该系统已经应用于广西物价局收费处和广西所有的县市物价部门,以及数千个物价收费单位.实际应用表明,该系统安全性高、透明性强、工作效率高.     

REM算法的改进

在分析REM算法和最优化流控模型的基础上,改用非线性优化理论的变尺度算法计算链路影子价格,从而改进了REM算法.模拟实验表明,改进后的REM算法队列十分平稳,收敛速度比原来的算法快,适用于高带宽网络.     

拟线性抛物型偏微分方程组解的振动性

利用Green定理和微分不等式,研究一类拟线性抛物型偏微分方程组 ((e)ui(x,t))/((e)t)=ai(t)Δui(x,t)+∑sk=1aik(t)Δui(x,ρk(t))-pi(x,t)ui(x,t)-∑mj=1fij[t,x,uj(x,σ(t))],i=1,2,...,m解的振动性,获得该类方程组在两类不同边值条件((e)ui(x,t))/((e)N)+gi(x,t)ui(x,t)=0,(x,t)∈(e)Ω×R+,i=1,2,...,m和ui(x,t)=0,(x,t)∈(e)Ω×R+,i=1,2,...,m所有解振动的若干充分条件 limt→∞ inf∫tσ(t)q(s)exp∫sσ(s)p(r)drds>(1)/(e).     

Hooke-Jeeves方法在简单约束优化中的推广

分别将无约束优化的线搜索和离散步Hooke-Jeeves算法推广到带广义界的简单约束优化,产生2个新算法,得到可行区间的计算公式．在适当条件下,证明线搜索的Hooke-Jeeves算法推广后仍具有全局收敛性,算法有效数值试验表明2个算法均是有效的．     

Research on object-oriented SOC design methodology

The growing complexity of System on Chip （SOC） requres a system level specicanon and design approach. High-level languages such as C＋＋/SystemC can play multiple roles in system design as target languages. There are many practical problems in the application of object-oriented methods for this goal. Based on the analysis of traditional and system-level design methodology, a new object-oriented SOC design methodology with object-oriented design patterns is proposed, which emphasizes high-level design and verification. Aiming at the final goal of developing design patterns specific to SOC design, the reuse of design patterns in SOC systems and the capability of new SOC design patterns are discussed. With the illustration of some concrete examples of SOC design patterns, the application of object-oriented design methodology in the SOC design process is presented.     

深部地层取心层裂机理研究

在深部高地应力地层中取心,岩心层裂(饼化)是一种常见的工程现象。岩心层裂和岩体的物性、力学性质以及原地应力密切相关。为研究钻井取心过程中岩心层裂现象的机理,结合川西南部地区Ａ井和B井取心过程中的岩心层裂现象,考虑岩石矿物组分与岩石脆性指数的关系,基于应力集中的非均匀岩石拉伸破坏模型,给出了岩心层裂现象产生的判据,采用理论计算和数值模拟方法对饼化现象进行了验证。研究结果表明：脆性矿物含量越高,岩石脆性越强,越易生成裂缝;岩心套取是一个卸载水平方向最大主应力的过程,卸载速度越快,损伤处的附加拉应力越大,且对应被激活损伤的尺寸就越小,当附加拉应力大于岩石抗拉强度时,会出现岩心层裂现象,随着取心的继续此过程将重复地发生下去。