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11.
12.
对常规测井和核磁共振测井的渗透率公式进行了比较 ,发现各渗透率公式存在相互联系。几种核磁共振测井渗透率公式的计算结果和实验室渗透率的对比表明核磁共振参数和渗透率有很好的相关性 ;改进的渗透率公式可以准确地求取岩心和地层的渗透率。 相似文献
13.
介绍PIMS在企业生产经营中的应用 ,运用PIMS可对炼油化工企业进行原油采购决策、加工保本点预算、效益预测、物流分配、整体流程优化、投资分析、瓶颈制约因素探讨、原料和产品库存管理、经济活动分析等 ,并结合生产装置特点和市场环境影响因素 ,获取最大生产经营效益。根据影子价格 ,找出提高效益的潜力 ,确定产品、中间产品或半成品合理价格 ,规范关联交易 ,增强企业市场应变能力 ,提高经济效益与管理水平。 相似文献
14.
Paul J. Flory 《Polymer International》1985,17(2):96-102
The earliest investigations on rubber elasticity, commencing in the 19th century, were necessarily limited to phenomenological interpretations. The realisation that polymers consist of very long molecular chains. commencing c. 1930, gave impetus to the molecular theory of rubber elasticity (1932-). according to which the high deformability of an elastomer, and the elastic force generated by deformation, stem from the configurations accessible to long molecular chains. Theories of rubber elasticity put forward from 1934-1946 relied on the assumption that the junctions of the rubber network undergo displacements that are affine in macroscopic strain. The theory of James and Guth (1947) dispensed with this premise, and demonstrated instead that the mean positions of the junctions of a ‘phantom’ network consisting of Gaussian chains devoid of material properties are affine in the strain. The vital significance of the distinction between the actual distribution of chain vectors in a network and their distribution if the junctions would be fixed at their mean positions went unnoticed for nearly 30 years. Experimental investigations, commencing with the incisive work of Gee in 1946. revealed large departures from the relationship of stress to strain predicted by the theories cited. This discrepancy prompted extensive studies, theoretical and experimental, during succeeding years. Inquiry into the fundamentals of polymer networks, formed for example by interlinking very long polymer molecules, exposed the need to take account of network imperfections, typically consisting of chains attached at only one end to a network junction. Various means were advocated to make corrections for these imperfections. The cycle rank ζ of the network has been shown (1976) to be the fundamental measure of its connectivity, regardless of the junction functionality and pattern of imperfections. Often overlooked is the copious interpenetration of the chains comprising typical elastomeric networks. Theories that attempt to represent such networks on a lattice are incompatible with this universal feature. Moreover, the dense interpenetration of chains may limit the ability of junctions in real networks to accommodate the fluctuations envisaged in the theory of phantom networks. It was suggested in 1975 that departures from the form predicted for the elastic equation of state are due to constraints on the fluctuations of junctions whose effect diminishes with deformation and with dilation. Formulation of a self-consistent theory based on this suggestion required recognition of the non-affine connection between the chain vector distribution function and the macroscopic strain in a real network, which may partake of characteristics of a phantom network in some degree. Implementation of the idea was achieved through postulation of domains of constraint affecting the equilibrium distribution of fluctuations of network junctions from their mean positions. This led in due course to a theory that accounts for the relationship of stress to strain virtually throughout the ranges of strain accessible to measurement. The theory establishes connections between structure and elastic properties. This is achieved with utmost frugality in arbitrary parameters. 相似文献
15.
蒸汽是石油化工装置中最重要的物料。随着石油化工工业的迅猛发展 ,蒸汽在其中扮演着越来越重要的多重角色。因此 ,对蒸汽系统的平稳控制 ,对石油化工生产装置平稳、高效地运行是至关重要的。传统的蒸汽减压站自控系统基建投资大 ,紧急情况下靠人工手动操作稳定蒸汽压力系统 ,往往造成生产的波动或大面积的停车。针对传统蒸汽减压站自控系统的弱点 ,提出蒸汽减压站自控系统的优化设计方案 ,该方案得以在大型生产装置成功应用。新方案不但节省了大量的基建投资 ,而且取得了良好的生产效益 相似文献
16.
17.
A novel combline filter is proposed for cellular‐radio base stations. The Q‐factor is significantly improved. The eigenvalue equation is expressed with the single‐team approximation in the gap region of the combline resonator. A two‐pole combline filter is designed. The calculation, simulation, and experiment results are presented and are in good agreement. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. 相似文献
18.
一级开发大柳树高坝原始库容比二级开发小观音高坝多 4 0亿m3 ,库容大带来的好处体现在 5~ 7月可多向下游增供水量 ,缓解下游河道断流 ;延长泄放清水时间 ;增加发电效益 ;满足宁蒙河段防凌要求 ;增加汛期集中泄水 ,减缓下游河道淤积萎缩 ;满足南水北调西线工程水量调节要求等。为了更好优化配置黄河水资源 ,从全局和长远利益考虑 ,应采用一级开发方案 ,修建大柳树高坝大库 相似文献
19.
J Schlipf 《Bulletin of Materials Science》1989,12(3-4):185-193
A model for propagating deformation bands is developed, based on a mechanical equation of state and on evolution equations
for the structure parameters. It is shown that, contrary to normal deformation, it is necessary to discriminate between global
parameters which depend solely on time elapsed and local parameters which are functions of the strain history. Correspondingly,
two sets of equations are presented, one describing the development of the global parameters in the course of time, the other
giving the evolution of the local state parameters in the course of deformation, i.e. as a function of strain. Measurable
quantities derived from the first set are the load serrations and the band velocity, while the second set yields the flow
stress and the strain profile of the propagating band. 相似文献
20.