Hydrodynamic Properties of Fe3O4 Kerosene-Based Ferrofluids with Narrow Particle Size Distribution

We investigate the hydrodynamic properties of Fe3O4 kerosene-based ferrofluids with narrow particle size distribution. The ferrofluids are synthesized by improving chemical coprecipitation technique. A narrow distribution of 8.6-10.8nm particle sizes is obtained from the magnetization curve with the free-form model based on the Bayesian inference theory. The fitting result is consistent with average particle size obtained from x-ray diffraction. With the increase of applied magnetic field and magnetic particle concentration, apparent viscosity of ferrofluids increases. At concentration 4.04%, the type of flow for the ferrofluid transforms from Newtonian to Bingham plastic fluid as the applied magnetic field increases.     

A Facile Synthesis of α-Phenylthio-α,β-Unsatuated Esters

α-phenylthio-α，β-unsaturated esters 6 were synthesized by Witting reaction of 3.which were prepared by a phenylsulfenyllation-trans-ylidation reaction.     

液体CO2在毛细管内的质量流量及临界流实验研究

本文进行了液体CO2在长度为0.5～5.9 m,内径为0.7 mm和2.0 mm,入出口压差为2.2 MPa和2.5 MPa的毛细管内的质量流量及临界流的实验研究.实验结果表明液体CO2在毛细管中的质量流量随毛细管内径、入出口压差的增大而增大,随长度的增加而逐渐减小;结果同时表明液体CO2在毛细管中产生了临界流现象,临界流随毛细管内径的增大而增大.在实验基础上回归出了适用于本实验条件的液体CO2在毛细管内的质量流量经验关联式,具有一定的工程指导意义.     

What Is Its Real Existing Form?——Theoretical and Experimental Studies on 2-Mercaptobenzothiazole

1 INTRODUCTION The study of heterocyclic molecules with aroma- tic rings and their absorptions on metals is of con- siderable importance from both theoretical and te- chnological points of view. These molecules are in- teresting because of their applications as corrosion inhibitors and flotation collectors, and their abilities to form self-assembly layers[1]. 2-Mercaptobenzo- thiazole (C7H5NS2, in the following MBT) is an important heterocyclic molecule, which can be used as corrosion …     

新型钝感炸药1-氧-2，6-二氨基-3，5-二硝基吡嗪的合成及表征

美国LLNL1995年合成出的代号为LLM-105的高能量密度材料，其化学名称为1-氧-2，6-二氨基-3，5-二硝基吡嗪（2，6-diamino--3，5-dinitropyrazine-1-oxide），分子结构式C4H4N605，分子量216．04，密度为1．913g／cm^3，氧平衡为-37．03％，生成热为-3．1kcal／mole，外观为亮黄色的针状晶体，比TATB的能量约高25％，且有着良好的热安定性，特性落高Dh50=117cm（RDX和HMX的特性落高30-32cm），对静电火花的刺激也很钝感。由于综合性能优异，LLM-105已经引起了国际炸药界的极大兴趣。     

KrF激光诱导BrC2F4Br+C2H4反应

激光诱导化学合成是一有兴趣的课题。不久前已报导了红外激光诱导调聚反应的结果。由于红外激光的加热特性,在许多情况下导致选择性与量子产率的矛盾。因紫外光反应的低温特性,有可能获得较高的选择性。但普通光源是宽带光源,对一个以平方断链为主的链反应,过强的吸收不利于链长的提高,而弱吸收又使反应速度太慢。为此,激光光源是满足最佳吸收的合宜光源。在使用了昂贵的激光光源后,经济上的合理性主要取决于链长     

X射线衍射研究N2+注入Si

本文首先给出了180keV的N₂⁺注入Si的X射线衍射(XRD)分布,然后用Levenberg-Marquardt最优化方法模拟实验曲线。根据XRD运动学理论,在我们给出的试探胁变函数和多层模型的基础上,用自编程序计算给出了晶格胁变随注入深度、剂量和退火温度的变化。最后我们对实验和计算结果进行了初步的分析讨论。 关键词：     

Orlicz-Sobolev空间的中点局部一致凸性

本文研究了Orlicz-Sobolev空间的中点局部一致凸性，通过结合Orlicz空间和Sobolev空间的技巧得到分别赋Luxemburg范数和赋Orlicz范数的Orlicz-Sobolev空间具有中点局部一致凸性的充要条件．