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701.
压裂液对油层伤害的若干机理研究 总被引:3,自引:0,他引:3
作者利用溶度积与离子积常数的关系讨论了压裂液中所含离子与地层流体之间的不配伍性;利用岩芯模型、微观砂岩模型等实验手段,就压裂液中的固形物对储集层渗流能力的影响和水锁效应的影响做了初步研究。 相似文献
702.
LiCl的Pitzer参数的优化 总被引:2,自引:6,他引:2
由于锂盐的重要性和氯化锂在电解质中的特殊性,LiCl和Ci2SO4的热力学问题一直被化学家所重视。Pitzer在其关于电解质的系列论文中给出的LiCl参数,适用的最大浓度仅为6m。1988年Hee—Ta1Kim等给出了适用于浓度直达饱和的参数。本文根据多年来我们对含锂盐体系的研究结果,经多种处理获得了LiCl和Li2SO4的新Pitaer参数。发现对于0—6m和6m一饱和不同浓度范围,LiCl的Pitzer参数截然不同。所获得的参数对于溶解度计算特别有意义。作者还从LiCl溶液的结构讨论了造成参数不同的原因。 相似文献
703.
M. F. Merienne A. Jenouvrier B. Coquart J. P. Lux 《Journal of Atmospheric Chemistry》1997,27(3):219-232
Previous experiments in the 400–500 nm region (Coquart et al., 1995) have been extended to the 200–400 nm region to determine the absorption cross-sections of NO2 at 220 K. The NO2 and N2O4 cross-sections are obtained simultaneously from a calculation applied to the data resulting from measurements at low pressures. A comparison between the NO2 cross-sections at 220 K and at ambient temperature shows that the low temperature cross-sections are generally lower, except in the region of the absorption peaks. Comparisons are also made with previous data at temperature close to 220 K. 相似文献
704.
Tectonic and geochemical characteristics and reserved conditions of a mantle source gas accumulation zone in eastern China 总被引:8,自引:0,他引:8
Along both sides of the Tancheng-Lujiang Fracture Zone in eastern China, a series of mantle source gas pools constitute a
massive-scale tectonic accumulation zone in NNE direction, with the mantle geochemical characteristics of high concentrations
of C02 and He, high3He/4He-40Ar/36Ar ratio system and high δ13Coo2 ratios (the main frequency, -3.4%— 4.6%), showing no difference from the tectonic framework of the area. In the area, the
tectonic environment is a rift formed as a result of diapiric mantle injection and crust thinning to form graben-type basins
and lithospheric fractures. The mantle-derived volcanic rocks and inclusions are well-developed and a high geothermal zone
(mantlesource) exists in the area. The characteristics of the three components (solid, liquid and gas) of mantle, concentrated
all over the same tectonic space zone, show that the rift system is of a good tectonic environment or passage for mantle degassing
and gas migration. The main types of the gas pools are volcano, fault-block, anticline, buried hill and so on, but most of
them are combination traps closely related with fracture. For the mantle source gas pools, rift is an optimum tectonic region,
and nearby lithospheric fracture, mantle source volcanic rocks or basement uplifts are a favourable structural location when
reservoir-caprock association develops. 相似文献
705.
706.
就4S技术在“数字黄河”工程中的应用进行了论述,并对4S技术应用的关键问题作了探讨。通过分析认为,4S及其集成技术是“数字黄河”的神经网络,是建设“数字黄河”工程的核心技术。 相似文献
707.
地籍地块间的空间拓扑关系 总被引:9,自引:4,他引:9
地籍的核心是地块,地块间存在着多种空间关系和时间关系。这些关系是地籍数据更新、信息查询与分析的基础。一个地块可看做2维欧氏空间中的一个面域,但目前对于两个面域间空间拓扑关系的描述方法非常有限,不能区分一个简单地块和一个复合地块(一个大地块中包围一个小地块的地块)间的空间拓扑关系。在Egenhofer等提出的包含空洞的两个面域间空间拓扑关系描述框架的基础上提出了一种描述地块间空间拓扑关系的双四元交模型(Double 4I,简称为D-4I模型),其特点是用两个四元组矩阵来描述最多包含一个复合地块的两地块间的空间拓扑关系,并用D-4I模型推导了一个简单地块和一个复合地块间的拓扑关系类型,共描述了31种地块间的空间拓扑关系,并总结了在地籍信息系统数据更新和数据质量控制中具有重要意义的7种常见的两个地块间空间拓扑关系。这些拓扑关系的描述与区分澄清了地籍地块间的空间拓扑关系类型,为地籍数据更新操作、地籍信息系统的数据质量控制、信息查询与分析推理等奠定了理论基础。 相似文献
708.
In natural waters arsenic normally occurs in the oxidation states +III (arsenite) and +V (arsenate). The removal of As(III) is more difficult than the removal of As(V). Therefore, As(III) has to be oxidized to As(V) prior to its removal. The oxidation in the presence of air or pure oxygen is slow. The oxidation rate can be increased by ozone, chlorine, hypochlorite, chlorine dioxide, or H2O2. The oxidation of As(III) is also possible in the presence of manganese oxide coated sands or by advanced oxidation processes. Arsenic can be removed from waters by coprecipitation with Fe(OH)3, MnO2 or during water softening. Fixed‐bed filters have successfully been applied for the removal of arsenic.The effectiveness of arsenic removal was tested in the presence of adsorbents such as FeOOH, activated alumina, ferruginous manganese ore, granular activated carbon, or natural zeolites. Other removal technologies are anion exchange, electrocoagulation, and membrane filtration by ultrafiltration, nanofiltration or reverse osmosis. 相似文献
709.
The degradation of dissolved organic matter (DOM) was studied in alkaline solution. The products were characterised using UV/vis spectroscopy, size‐exclusion chromatography (SEC), and by the analysis of low‐molecular‐weight organic acids (LMWOA). The degradation experiments were performed with water from a brown water lake or its isolated fulvic acid fraction and sodium hydroxide at different reaction times and temperatures. Depending on the wavelength and the reaction time, the UV/vis absorbance between 230 nm and 600 nm increased or decreased. The behaviour of model compounds during reactions in alkaline media was compared to the UV/vis spectroscopic behaviour of DOM. The release of LMWOA was described by kinetic data and compared to the data of model reactions. Evidence was given for the carboxylic esters playing a significant role in the release of LMWOA only during the beginning of the alkaline degradation. The results gained by SEC with on‐line UV and DOC detection showed that the average size of DOM was decreasing, and that a major part of the degradation products consisted of low‐molecular‐weight mono‐ and dicarboxylic acids. 相似文献
710.
In natural waters arsenic concentrations up to a few milligrams per litre were measured. The natural content of arsenic found in soils varies between 0.01 mg/kg and a few hundred milligrams per kilogram. Anthropogenic sources of arsenic in the environment are the smelting of ores, the burning of coal, and the use of arsenic compounds in many products and production processes in the past. A lot of arsenic compounds are toxic and cause acute and chronic poisoning. In aqueous environment the inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are the most abundant species. The mobility of these species is influenced by the pH value, the redox potential, and the presence of adsorbents such as oxides and hydroxides of Fe(III), Al(III), Mn(III/IV), humic substances, and clay minerals. 相似文献