聚乙二醇型含硼表面活性剂的合成

含硼特种表面活性剂具有碳氢表面活性剂无法替代的长处,具有广阔的应用前景。因此,合成含硼表面活性剂意义重大。本论文采用聚乙二醇、三乙醇胺、硼酸为原料,应用潜溶剂法（以甲苯为溶剂,通过回流带出酯化反应所生成的水）制备了含硼表面活性剂。设计正交实验确定最佳的酯化条件。实验结果表明,最佳的酯化条件为：温度（90±2）℃,硼酸、三乙醇胺、PEG（400）的摩尔比为2：1：2。最佳酯化条件下合成的聚乙二醇型三乙醇酰胺硼酸酯表面活性剂的电导率为0．36mS·cm^-1,表面张力为67．00mN·m^-1,pH值为8～9,水溶液为均一透明溶液。所合成的硼酸酯表面活性剂可以很好地应用于金属切削加工液中。     

Validation of an effective oxidation pressure model for liquid binary alloys

Dynamic surface-tension measurements using the sessile drop method and acquisition times of a few seconds make it possible to study the evolution of the surface of molten metals and alloys and so reliably validate the predictive models of the interactions between pure liquid metals and an oxidizing atmosphere, in both an inert gas carrier and in a vacuum. The presence of active oxidation contributes to maintaining surface cleanness and then strongly affects the shape of the boundary separating oxidation and de-oxidation regimes. Recently the general physical–mathematical analysis we developed for pure liquid metals has been extended to liquid binary alloys and their oxides. In this work we present the experimental results of tests on some binary alloys chosen as test systems to try to obtain a preliminary validation of the extended model. The theoretical results obtained, indicating that the behaviour of the alloy towards oxidation tends to be similar to that of the less oxidizable component, have thus been confirmed experimentally.     

低张力体系在低渗透油藏中降压增注实验研究

简要介绍了表面活性剂降压增注原理,由阴离子表面活性剂SDBS和两性表面活性剂DJ—M以质量比4：1复配而成的低张力体系,能将油水界面张力在较宽温度和较大矿化度范围内降低至10^-3 mN／m数量级。考察了复配低张力体系降压增注和驱油性能,结果表明,复配低张力体系能使注水压力平均降低37．5％,增加注水量,采油率提高8个百分点。     

Convection phenomena at reduced gravity of importance in space processing of materials

The basic aspects of convection processes are delineated. It is shown that even in weak gravitational fields buoyancy can induce fluid motions. Furthermore, at reduced-gravity other non-gravity forces such as surface or interfacial tensions,g-jitter, thermal-volume expansions, density differences due to phase changes, and magnetic and electric fields can induce fluid motions. The various types of flow possible with these various driving forces are described and criteria for determining the extent and nature of the resulting flows and heat transfer are presented. The various physical mechanisms that can occur separately and in combination are indicated and the present state of knowledge of each of the phenomena is outlined.