压裂水平井多裂缝系统的试井分析

压裂水平井技术是实现油气田经济开发的重要手段之一，而试井分析技术是压裂水平井的关键技术。在分析国内外压裂水平井试井模型和试井解释方法发展现状基础上，研究了压裂水平井多裂缝系统试并模型和解释方法，并分析了其压力动态特征。采用解析解与数值解相结合的半解析法构造渗流数学模型，并针对边界复杂情况，在模型中引入裂缝离散化机制。     

我国有线电视的网络媒体价值

阐述有线电视网络媒体的特点，有线电视网络媒体面临的困境及解决办法，最后展望有线电视网络媒体价值。     

Flow of solutions of hydroxypropyl guar-poly(ethylene oxide) mixtures through a porous medium

Summary In flow through porous media, solutions of poly(ethylene oxide) (PEO) exhibit extension thickening, whereas hydroxypropyl guar (HPG) solutions are shear-thinning at high concentrations. The results show that the extension-thickening exhibited by PEO solutions becomes less critical with increasing flow rate as the concentration of HPG in the solution is increased. At high concentrations of HPG, the presence of PEO inhibits the shear-thinning behaviour, without increasing the apparent viscosity of the solution. The presence of HPG reduces the rate and extent of degradation of PEO in the flowing solution.     

Characterization and catalytic gasification of the aqueous by-product from vacuum pyrolysis of biomass

Spruce wood residues were treated in a vacuum pyrolysis Process Development Unit with a throughput capacity of 28 kg/h. Two aqueous phase condensate samples with COD concentration varying between 190 and 255 g/L were produced and sequentially extracted with dichloromethane and ethylacetate solvents. The soluble organic matter was composed of acidic, phenolic, alcoholic and ketonic compounds. The insoluble fraction was sequentially distilled at 100 and 110°C under atmospheric pressure. Mainly water was recovered in the first distillate, while the second distillate contained 30.4% formic and acetic acids, 69.4% water and 0.2% residual organic compounds. The distillation residue was rich in oxygen and was essentially insoluble in any organic solvent. The two aqueous phase pyroligneous samples were treated in Bat-telle's Thermochemical Environmental Energy System (TEESr?), a registered service mark of Onsite*Ofsite, Inc. of Duarte, California, U.S.A. The results of the tests showed that similar results were obtained with either feedstock. In batch tests a COD reduction of 99% was achieved. The product gas composition was typically about 49% methane, 5% hydrogen, 1 % ethane and 45% carbon dioxide. Tests in a continuous stirred-tank reactor produced reproducible data which can be used for process scale-up. Catalyst lifetime was identified as needing further improvement. The preliminary results demonstrated the technical feasibility of the catalytic gasification process as a useful step in the recovery of energy from the secondary condensate stream and the cleanup of the by-product water from vacuum pyrolysis of wood.     

An economic and environmental assessment of biomass utilization in lignite‐fired power plants of Greece

The environmental and socio‐economic impacts of biomass utilization by co‐firing with brown coal in an existing thermoelectric unit in Greece or through its pure combustion in a new plant were studied and evaluated in this work. The 125 MW_e lignite‐fired power plant in Ptolemais Power Station (Western Macedonia) was used as reference system. The environmental benefits of the alternative biomass exploitation options were quantified based on the life cycle assessment methodology, as established by SETAC, while the BIOSEM technique was used to carry out socio‐economic calculations. The obtained results showed clear environmental benefits of both biomass utilization alternatives in comparison with the reference system. In addition, co‐firing biomass with lignite in an existing unit outperforms the combustion of biomass exclusively in a new plant, since it exhibits a better environmental performance and it is a low risk investment with immediate benefits. A biomass combustion unit requires a considerably higher capital investment and its benefits are more evident in the long run. Copyright © 2005 John Wiley & Sons, Ltd.     

Microstress estimate of stochastically heterogeneous structures by the functional perturbation method: A one dimensional example

A new functional perturbation method (FPM) for calculating the probabilistic response of stochastically heterogeneous, linear elastic structures is developed. The method is based on treating the governing differential operator as well as the unknown displacement function as a functional of material modulus field. By executing a functional perturbation around the homogeneous case, a set of successive differential equations is obtained and solved, from which the average and variance of any local parameter (displacements, stresses, strains) can be found. For a linear problem, the equations to be solved in each approximation order differ from the one for the homogeneous case by a pseudo external loading (right hand side) part only. Thus, only the Green function for the homogeneous case is needed for an analytical solution of the corresponding heterogeneous problem. A one dimensional stochastically heterogeneous rod embedded in a uniform shear resistant elastic medium is solved as an example. The statistical variance of displacements and stresses are found analytically, including the edge regions. Morphological (grain size) and material (modulus) effects on the stochastic response are demonstrated. The above results are essential for estimating the stochastic features of local stress concentrations, which are the source for many strength-related macro properties of materials. Extensive usage of generalized functions (Dirac operator and its derivatives) is needed for the analysis.     

超临界流体中的酶催化

与其他非水相酶催化介质相比 ,超临界流体有其独特的优越性。阐述了超临界流体的概念、对超临界流体的选择原则以及在超临界流体中酶催化的各种影响因素 ,还讨论了在此类流体中酶催化的应用和发展前景     

炼制进口原油常减压装置的腐蚀问题

胜利炼油厂第三常减压装置改炼进口高硫原油或进口原油掺炼陆上原油后 ,设备腐蚀明显加重 ,致使换热器E2 4/ 1和空冷器A1/ 1腐蚀率高达 2 .5mm/a。腐蚀加重的主要原因是由于原油脱后盐含量偏高 ( 10～ 2 0mg/L)、硫含量高 ( 1.5 %～ 2 .5 % )所造成的塔顶及其冷凝冷却系统H2 S -HCl-H2 O环境的腐蚀 ,高温重油部位则主要是环烷酸引起的腐蚀。同时提出了改造电脱盐系统、优化原油调配和加强注剂管理等一系列措施     

Media ratings for violence and sex: Implications for policymakers and parents.

This article reviews research on the implementation of media-rating systems, parents' use and evaluation of them, and the impact of ratings on children. Although half or more of parents report using media-rating systems, understanding of various components of the systems is low, particularly for television ratings. A meta-analysis of national polls shows that parents overwhelmingly prefer that ratings specify content, rather than giving age recommendations. A second meta-analysis, of experiments testing the effects of ratings on children's interest in programs, shows that ratings indicating restricted or controversial content have a deterrent effect for children under age 8 but that, by age 11 and especially for boys, the ratings show a small enticement effect. This effect occurs for both age-based and content-based ratings. Implications for policymakers and parents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

分形理论在固体吸附式制冷系统中的应用研究

固体吸附式制冷系统中吸附剂一般是多孔介质结构，吸附剂的内部结构特征对传热特性和吸附质的传质特性有直接影响，进而影响吸附解吸时间。本文探讨利用分形理论来分析固体吸附剂的结构特点，为目前通过对吸附剂的固化处理来提高吸附剂的传热速率的处理方法提供理论上的分析，并指出最佳分形维数的分形结构。