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排序方式: 共有9461条查询结果,搜索用时 390 毫秒
941.
A new capillary viscometer has been constructed and the viscosities of methanol, 2-methyl-2-propanol, and their mixtures have been measured at two temperatures, 303 and 323 K, and at pressures up to 30 MPa. Simple empirical equations are given to represent the pressure and composition dependences of the viscosity within the experimental uncertainty of ±2%. 相似文献
942.
New relative measurements of the viscosity of liquid toluene are reported for the temperature range 218 to 378 K. They supplement the existing data, which have been obtained mostly above 273.15 K. The relative accuracy of the results is estimated between –1 and 1.38% at 218 K, narrowing to one of –0.74 and 1.12% at 378 K. The experimental data have been correlated well within these estimates by an empirical temperature function. A comparison with previous experimental and compiled or evaluated data includes references since 1894 and is the most comprehensive survey so far. The agreement with the present data is generally very good. There is a need for further measurements with instruments other than capillary viscometers and in the low-temperature range from the triple point (178.15 K) to 273.15 K.Dedicated to Professor Dr.-Ing. Karl Stephan on the occasion of his 60th birthday. 相似文献
943.
碱/聚合物二元复合驱粘度稳定剂研究 总被引:3,自引:0,他引:3
针对碱/聚二元复合驱在现场应用中暴露的粘度不稳定问题,通过热氧老化实验,在研究三种粘度稳定体系的基础上,综合考虑复合驱不稳定因素,研制了GH-01复合型稳粘剂。结果表明,实验所用稳定剂都起到了一定粘度改善作用,其中GH-01效果尤为突出,仅需10mg/L即能使老化四个月的二元体系(碱1.25% 聚合物0.15%)粘度达到26.8mPa.s,比原体系粘度提高了5.5倍,同时该稳粘剂合成简单,价格低廉,对解决聚驱和复合驱过程中的粘度不稳定问题有积极意义。 相似文献
944.
The paper reports new measurements of the thermal conductivity of carbon tetrachloride in the temperature range 310 to 364 K at pressures up to 0.22 GPa. The experimental data have an estimated uncertainty to ±0.3%. The hard-sphere theory of transport in dense fluids is employed to formulate a correlation scheme for the thermal conductivity as a function of density. A single equation represents the dependence of the thermal conductivity on density for all isotherms, the isotherms being distinguished by a characteristic value of the molar volume. It is shown that earlier measurements of the viscosity and self-diffusion coefficient of carbon tetrachloride may be represented in a similar fashion using consistent values of the characteristic volume. 相似文献
945.
J. V. Sengers 《International Journal of Thermophysics》1985,6(3):203-232
The paper reviews the theoretical and experimental results for the asymptotic behavior of the dynamics of critical fluctuations in fluids and fluid mixtures near a critical point. The implications of these results for the development of accurate representative equations for the viscosity and thermal conductivity of gases in the critical region are discussed.Invited lecture presented at the 10th International Conference on the Properties of Steam, Moscow, USSR, September 2–7, 1984. 相似文献
946.
董宏成 《西华大学学报(自然科学版)》1989,8(3):174-182
本文从粘性可压缩非定常流这种最一般形式的纳维——斯托克斯方程和连续性方程出发,利用时均化概念,同时考虑到运动中各参量的不同特性而将其分为随机性和非随机性的,将基本方程进行了时均化处理及变换,初步揭示了粘性可压非定常湍流由于脉动引起的流体动力方程中的有关附加项、能量的变化形式以及运动中的应力问题,分析了粘性和脉动在流体运动中各方面的作用。 相似文献
947.
This article relates the fibrillation of liquid crystalline polymer (LCP) under shear in its blend with a thermoplastic polymer (TP) to the relative rate of energy utilization in the LCP and TP phases. The development of a criterion based on the energy relationship for predicting LCP fibrillation in the blend is discussed. The formation of LCP fibers in the blends of LCP with polycarbonate (PC), polyethylene naphthalate (PEN), high‐density polyethylene (HDPE), polypropylene (PP), and silica‐filled polypropylene (PP) was studied to validate the criterion and to demonstrate its applicability. For all the blends, viscosity data were obtained by using a capillary rheometer, which was subsequently used to estimate the rate of energy utilization in the LCP and the matrix phases. The predictions based on the proposed criterion were verified through the morphological investigations carried out on the extrudates obtained from the same capillary experiments. The energy‐based criterion was easy to implement, could account for the effect of variable LCP concentration and fillers in the blend, and could provide reliable predictions for a variety of LCP/TP blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3314–3324, 2003 相似文献
948.
介绍了内燃机润滑油的分类法 ,阐述了内燃机油的主要指标及检测方法 ,提出了判断内燃机设备磨损情况的方法 ,预测设备可能发生的故障 相似文献
949.
比较了常规聚酯(PET)和改性聚酯(CDPET)的热性能,分析了不同温度和时间的特性粘度[η]和分子量M变化规律,结果表明,常规聚酯的热性能优于改性聚酯。 相似文献
950.
The detailed flow structures in bubble columns with and without internal draught tube have been investigated using the PIV technique. The onsets of transition due to vortex formation and different flow patterns with and without draught tube have been studied using the drift‐flux model and the experimentally measured Reynolds stresses. The role of solid particles and liquid viscosity, as well as bubbling orifice configuration on the flow patterns and regime transition has also been studied and discussed. 相似文献