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关键词： 液体表面   张力系数   拉脱法   可视化  

摘要： 拉脱法测量液体表面张力系数实验是大学物理实验中的一个经典实验项目。该实验采用硅压阻式力敏传感器测量力的大小,通过数显表读取力对应的电压值。但是,通过数显表只能看到液膜断裂前后瞬时拉力对应的电压值,不能看到力随位移变化的曲线,不便于直观理解力的变化过程。实验教学中,学生容易将电压极大值与液膜断裂前瞬间的电压值混淆,从而导致测量值不准确。因此,对拉脱法测液体表面张力系数的传统装置进行改进,将实验装置与计算机结合,由计算机直接采集和处理数据,提高了实验的可视化和自动化程度,便于学生理解力的变化过程,提高了实验结果的准确性。

关键词： 煤层注水   润湿性   表面活性剂   表面张力   接触角  

摘要： 为了提高现场煤层注水效果,针对润湿性较差煤体,提出采用添加表面活性剂的方法以提高煤体润湿性。以贵州百色集团六龙煤矿煤样为例,根据表面活性剂种类选出4种有代表性且廉价易得的表面活性剂,通过测定纯水和添加表面活性剂的溶液的表面张力及其与煤体的接触角,优选出磺化玻拍酸二辛酷钠盐(快速渗透剂T)作为最佳表面活性剂,最佳浓度为0.4%。

关键词： 表面吸附   表面张力   纯液体   强电解质溶液   相变  

摘要： 本文定量研究了6种纯液体的表面张力与温度的关系,进一步预测了这些液体从体相到表面相的相变过程中所放出的热量,并提出放热的根源是分子在表面相更有序的排列引起了熵的减少。本文还研究了CaCl_2和K_2CO_3水溶液的表面张力随浓度的变化关系,理论模拟结果与实验数据非常一致;同时,在给定β值的情况下,还对16种强电解质溶液的表面层厚度进行了估算,对所揭示的溶液表面层增厚现象给出了理论解释。

关键词： 凝析气藏   相态特征   P-T相图   流体组成  

摘要： 随着深层油气勘探的不断深入,国内外深部地层中发现了相当数量的凝析气藏,而凝析气藏研究的难点在于:烃类流体相态呈复杂多样的特征,这对凝析气藏的勘探、开发和资源预测等都带来了困难,故查明油气相态的成因机制和分布规律,预测油气相态,已成为油气地质理论研究亟待解决的问题。国外研究认为烃类的化学组分、温度和压力系统是影响油气相态多样性的关键因素。近年来,国内学者针对塔里木盆地和渤海湾盆地凝析气藏,初步探索了油气相态的多样性和成因的复杂性,提出了多套烃源岩的发育、多期油气的充注以及成藏后圈闭的多次调整、改造甚至破坏是导致油气相态复杂多样的观点,为流体相态研究奠定了理论基础。

关键词： 松江河金矿床   地质特征   成矿流体   流体包裹体   物理化学条件  

摘要： 松江河金矿床位于夹皮沟—海沟金成矿带的中部,矿体主要产于新太古界色洛河岩群中部岩性段的底部,其热液成矿作用可划分为石英-黄铁矿、多金属硫化物-石英、石英-碳酸盐3个阶段。流体包裹体岩相学研究表明,多金属硫化物-石英阶段主要发育气液二相包裹体、含CO_2三相包裹体及少量纯CO_2包裹体。测温结果显示,成矿流体具有低盐度(1. 38%～6. 81%Na Cleqv)、低密度(0. 41～0. 86 g/cm^3)的特点,成矿温度集中于260℃～390℃,成矿压力为70～106 MPa,成矿深度为6. 8～8. 7 km。成矿过程中,流体经过了H_2O-CO_2-NaCl体系的不混溶,导致金在成矿流体中的溶解度降低,发生沉淀作用并富集形成金矿床。

关键词： 流函数   Boussinesq方程   波浪爬升  

摘要： 基于高精度速度势Boussinesq方程建立了三维数值波浪水池。在造波区域采用流函数理论生成线性及非线性波浪,消波区域采用人工阻尼函数进行消波。数值水池试验区段采用有限差分方法计算Boussinesq方程中空间导数,并基于四阶龙格库塔方法进行时间步进模拟波浪传播和衍化过程。本文对波浪传播至垂直挡板后反射叠加过程进行数值模拟并与文献结果进行对比验证分析。数值计算结果表明波浪的非线性对于爬升高度具有显著影响。

关键词： 大豆卵磷脂   蛋黄卵磷脂   蛋黄磷脂酰胆碱   脂肪酸   乳化能力   表面张力  

摘要： 目的:对不同磷脂的组成成分和脂肪酸比例进行研究,比较不同磷脂在乳剂中的乳化能力。方法:采用《中国药典》中蛋黄卵磷脂(供注射用)的磷脂酰胆碱、磷脂酰乙醇胺和有关物质含量的测定方法,分别测定大豆卵磷脂、蛋黄卵磷脂以及蛋黄磷脂酰胆碱中的磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)、溶血磷脂酰胆碱(LPC)、溶血磷脂酰乙醇胺(LPE)、磷脂酰肌醇(PI)、鞘磷脂(SM)的含量;采用气相色谱法对大豆卵磷脂、蛋黄卵磷脂、蛋黄磷脂酰胆碱中主要的脂肪酸进行含量测定;分别采用大豆卵磷脂、蛋黄卵磷脂和蛋黄磷脂酰胆碱作为乳化剂进行脂肪乳的制备,以脂肪乳的平均粒径、粒径分布、D_(90)值、ζ电位和表面张力作为考察指标,对3种不同磷脂的乳化能力进行综合评价。结果:大豆卵磷脂、蛋黄卵磷脂、蛋黄磷脂酰胆碱中成分组成,脂肪酸组成及比例均有明显差异;采用大豆卵磷脂、蛋黄卵磷脂、蛋黄磷脂酰胆碱作为乳化剂制备的乳剂的物理稳定性也有显著差异。结论:大豆卵磷脂、蛋黄卵磷脂以及蛋黄磷脂酰胆碱由于其来源和制备工艺不同,使得其各自的成分和脂肪酸组成不一致,组成成分和脂肪酸的差异进一步导致了其乳化能力有所差异。

关键词： [emim]Ac   黏度   表面张力   比热容   实验测定   模型关联  

摘要： 新型功能性离子液体[emim]Ac吸收CO_2性能良好,但物性研究匮乏。在298.15—338.15 K温度范围内测定了离子液体[emim]Ac的黏度和表面张力及308.15—428.15 K温度范围内的比热容。结果表明:当压力一定时,离子液体[emim]Ac的黏度和表面张力均随温度的升高逐渐减小;比热容随温度的升高先减小后逐渐增大;分别采用Litovitz方程和Eotvos方程进行黏度、表面张力数据的关联,比热容与温度的关联式符合温度的N次函数,得出平均相对偏差分别为:0.04%,1.11%,3.53%,理论关联与实验测定结果一致。通过研究补充了离子液体[emim]Ac的相关物性,验证了模型关联对离子液体基础物性关联的可行性。

关键词： High-power mechanical pump   Clocking position   Vaned diffuser   Circular casing   Hydraulic performance   Flow loss visualization  

摘要： The high-power mechanical pumps used in thermal power plants consume a considerable amount of electrical energy. Thus it is of great importance to improve the efficiency from every potential feature of such pumps. In this study, the clocking position of the pump, defined as the circumferential position of the vaned diffuser relative to the circular casing, is investigated to improve the hydraulic performance. Thereafter, the flow loss visualization method is employed to depict the loss caused by clocking positions with the help of entropy production theory based on computational fluid dynamics (CFD). The numerical results are then validated by experiments. At the design condition, the numerical maximum difference in the hydraulic efficiency is 2.61% while the head of each scheme meets the design requirement, The clocking position influences the total pressure loss coefficient more in the circular casing than other components, and the largest difference in the circular casing is 1.91%. Furthermore, the proven visualization method reveals that the clocking position introduces additional flow losses in the circular casing of the worst scheme, and even increases the loss in the vaned diffuser. This study can also provide a new perspective to investigate the optimal assembly strategy for other hydraulic machinery. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Oil sand bitumen   Fast thermal cracking   Product distribution   Chemical structure   Py-GC/TOF-MS   Fluidized bed reactor  

摘要： In order to obtain a deep insight into the upgrade of oil sand bitumen (OSB), the composition, distribution and chemical structure of products obtained from the fast thermal cracking of the OSB were investigated via Py-GC/TOF-MS and a laboratory-scale fluidized bed reactor. A detail composition information of fast thermal-cracking products of the OSB was determined by Py-GC/TOF-MS, which mainly contained alkenes (1-alkenes, iso-alkenes and cycloalkenes), alkanes (n-alkanes, iso-alkanes and cycloalkanes), diolefins, aromatics and sulfur-containing compounds. The distribution of fast thermal-cracking products varied under different temperature. Alkenes were the uppermost style in volatile products at the temperature ranging from 500 degrees C to 700 degrees C, whereas with the temperature further rising to 800 degrees C, aromatics products became predominant and were mainly generated from the deep cleavage of alkyl substituent groups and the secondary reactions to form aromatics. Moreover, the relative content and carbon number distribution of volatile products along with various temperature were summarized. The thermal cracking experiments of the OSB over silica sand in a laboratory-scale fluidized bed reactor showed that the gas products had a remarkable increase in yield as the temperature increase, which was connected with the increase in methane and ethylene of dry gas as well as propylene and butenes of LPG. The coke yield also exhibited an increase tendency with the enhancement of temperature, while this variation was slighter in comparison to that of gases. Conversely, the yield of liquid products gradually decreased with the temperature, which was closely related to the significant decrease of VGO and heavy oil fractions due to the coke formation of polyaromatics and the intensive rupture of alkyl side chains. Nevertheless, the light oil fraction (diesel and gasoline) displayed the different variation along with the temperature, which increased firstly and th