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1.
在油气井的试油测试资料中,压力恢复曲线有时会出现下滑现象,常被认为是施工失误所致。本文以实际资料为例,分析了“下滑恢复”的压力响应特征和影响因素,认为只在低渗透地层有可能产生“下滑恢复”现象,并提出了避免“下滑恢复”的施工建议。 相似文献
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A set of six coals ranging in rank from lignite to hvA bituminous was swollen with a series of alkyl-substituted pyridines and a smaller set of 4-alkylanilines. The size and branching of the alkyl groups was varied and the effect of this variation on the dissolution of the amines in the coal and the resulting coal swelling was measured volumetrically. In a few cases, substituents which hindered the amine nitrogen were studied. The lignite and subbituminous coal have a much higher tolerance to branched, bulky groups than do the bituminous coals. The presence of tertiary groups in a solute strongly inhibits their dissolution in bituminous coals. Bituminous coals behave as if extensive parallel packing of structures occurs. Often, they can accept very large planar groups but have a low capacity for branched groups. 相似文献
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通过具体工程实践,在吸收现有滑模工艺技术的基础上,对平台扭转、中心垂直度控制等关键工艺进行创新,为提高工程质量提供技术保证,达到了创省级优质工程的效果。 相似文献
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Modified (α‐diimine)nickel(II) catalysts are suitable for ethylene oligomerization reactions. Due to the mechanism (“chain running”), the formation of double‐bond isomers and branched olefins can be observed. The obtained oligomer mixtures show a Schulz–Flory distribution. Increasing ethylene pressure favors the selectivity of α‐olefin formation. The same effect can be observed when Lewis bases like thiophene or furane are added to the oligomerization reaction mixture. These results can be related to an interaction of the additives with the catalytic active species during the oligomerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1356–1361, 2003 相似文献
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提出了一种新颖的基于自适应小波基优化选择和心理声学模型相结合的数字音频信号的透明质量编码方法,保证固定失真水平上使每帧信号的变换系数的动态分配的比特数最少,并且利用动态码本的方法来消除音频信号的统计冗余,进一步压缩比特率,对于抽样率为44.1kHz每样值用16比特线性码表示的光盘单声道音乐信号可以压缩到64kBPS左右。 相似文献
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SynthesisandSpectralPropertiesofMixedLigandComplexesofLanthanidePerchloratewithBis(phenylsulfinyl)ethaneandOrganicLewisBase... 相似文献
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In the area of image retrieval from data bases and for copyright protection of large image collections there is a growing demand for unique but easily computable fingerprints for images. These fingerprints can be used to quickly identify every image within a larger set of possibly similar images. This paper introduces a novel method to automatically obtain such fingerprints from an image. It is based on a reinterpretation of an image as a Riemannian manifold. This representation is feasible for gray value images and color images. We discuss the use of the spectrum of eigenvalues of different variants of the Laplace operator as a fingerprint and show the usability of this approach in several use cases. Contrary to existing works in this area we do not only use the discrete Laplacian, but also with a particular emphasis the underlying continuous operator. This allows better results in comparing the resulting spectra and deeper insights in the problems arising. We show how the well known discrete Laplacian is related to the continuous Laplace-Beltrami operator. Furthermore, we introduce the new concept of solid height functions to overcome some potential limitations of the method. 相似文献
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The corrosion inhibition of austenitic chromium–nickel steel by two Schiff bases, N-(1-toluidine)salicylaldimine and N-(2-hydroxyphenyl)salicylaldimine, was investigated in sulphuric acid medium. The effect of concentration and temperature on inhibition properties was determined. It was found that when the concentrations of inhibitor were increased the inhibition efficiencies () and surface coverage () increased. Some thermodynamic parameters such as free energy of adsorption, G
ads, and enthalpy, H, were determined for the Schiff bases. Experimental results agree with the Temkin isotherm for N-(1-toluidine)salicylaldimine, but the Langmuir isotherm is more appropriate for N-(2-hydroxyphenyl)salicylaldimine. 相似文献