煤焦油蒸馏的新产品-改质沥青的生产

论述了利用热缩聚方法对中温沥青进行改质处理来生产改质沥青 ,提高了沥青的软化点、β树脂含量及结焦值 ;并介绍了生产工艺的特点、主要工艺参数及产品的质量     

不同活化剂对石油焦基活性炭孔结构的影响

以石油焦为原料 ,Na OH,KOH和 Na2 CO3 为活化剂制备活性炭 ,采用氮气吸附考察了不同活化剂对活性炭的比表面积、中孔和微孔孔径分布、孔容积及平均孔径等孔结构的影响 .结果表明 :KOH活化制备的活性炭包含 1 nm的微孔和 4nm的中孔 ,总孔容 0 .648cm3 /g,比表面积大 ;Na OH制备的活性炭以 1 nm的微孔为主 ,占总孔容 ( 0 .1 65 cm3 /g)的 98% ,平均孔径 1 .83nm;Na2 CO3 制备的活性炭以 4nm的中孔为主 ,占总孔容 ( 0 .1 43cm3 /g)的 68.5 % ,平均孔径 3.42 nm,比表面积小 .3种样品的孔径都呈现出多峰分布特征 .KOH和 Na2 CO3 活化制备的活性炭的 N2 吸附脱附曲线属于 型 ,Na OH活化制备的活性炭吸附脱附曲线属于 型 .     

Properties of poly(n‐butyl methacrylate) prepared by reverse atom transfer radical polymerization in an aqueous dispersed system

Reverse atom transfer radical polymerization (ATRP) of n‐butyl methacrylate (BMA) in waterborne media using Cu(II) complexes with azo initiators (i.e., reverse ATRP) was conducted. The influence of several factors, such as surfactant, catalyst, and reaction time, on the stability of the emulsion, the particle size, the morphology of the emulsion particles, and the control of the polymerization was investigated. The results showed great differences between ATRP and conventional emulsion polymerization, especially the nucleation mechanism and the kinetics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1542–1547, 2003     

用加权余量法计算球形催化剂的有效因子

本文利用加权余量法计算了等温球形催化剂的有效因子,并对催化反应n=1,2的两种情况与其它简化法进行了比较.文中取Dirac函数作为权函数,形式简单,在袖珍计算器上就能完成计算.其结果:当n=1时,与解析解非常接近;当n=2时,优于其它三种简化解法,很接近数值解.     

A rheological model for iron oxide suspensions

We have examined the rheological properties of a Co-adsorbed γ-Fe₂O₃ magnetic suspension with polyurethane (PU) as a binder and methyl ethyl ketone (MEK) or cyclohexanone (CH) as a solvent. A Haake RV20 viscometer was used to measure the suspension viscosity and the vane method was adopted to determine the fluid yield stress. A rheological model which can be viewed as a combination of the Casson model and the Bingham model is proposed to describe the suspension viscosity. The effects of temperature, particle content, and binder concentration are included in the model.     

An evaluation of commercial nickel catalysts during hydrogenation of soybean oil

The activities of several commercial nickel catalysts were determined by measuring their activation energies. Among these catalysts, G95E, Resan 22, Nysosel 222 and 325, all with low activation energy, were more active than DM3 and G95H, which had higher activation energy. However, the less active catalysts increased the linoleate selectivity of soybean oil during hydrogenation. The yields of bothtrans isomers and winterized oil were higher for the more selectively hydrogenated oil catalyzed by the less active catalysts. In the sensory evaluation, the fractionated solid fat that contained moretrans isomers was lower in flavor scores than the fractionated liquid oil after hydrogenation and winterization of soybean oil.     

Effects of Stearic Acid on the Injection Molding of Alumina

This research investigated the influence of stearic acid on the injection molding of alumina, by varying the concentration of stearic acid. The interaction between stearic acid and alumina was identified using transmission infrared spectroscopy, indicating stearic acid preferentially adsorbed onto the alumina powder surface. In addition to slightly modifying the intrinsic binder viscosity, stearic acid adsorbed onto the powder surface changed the flow behavior of the mixtures from dilatant flow to pseudoplastic flow at low temperatures. As a result, inhomogeneous distribution of binder in the injection-molded parts was minimized with increased stearic acid concentration. However, the possibility of forming bubbles in the mixtures arising from vaporization of stearic acid was enhanced. Additionally, the binder burnout temperature range was broadened with the increase of stearic acid concentration.     

Electrodeposition of Ni-transition alloys for the oxygen evolution reaction

The oxygen evolution reaction (OER) is the anodic reaction in several industrial electrolytic processes. The objective of this work was to develop a new electrocatalytic material for long-lasting and economical high performance electrodes. New electrodes were prepared by electrodeposition of nickel, nickel-ruthenium and nickel-iridium alloys. They were then activated by anodic polarization at 100 mA cm^–2 to form an oxide layer. The electrocatalytic activity was characterized for the OER in 5M KOH solution. The results show that nickel-iridium alloys provide greater electrocatalytic activity for the OER and better corrosion resistance than nickel-ruthenium in alkaline solution. The effects of transition elements on improving the performance of the nickel electrode are then discussed.Notation b Tafel slope - i _ex exchange current density - i _dp electrodeposition current density - i _OER oxygen evolution reaction current density - C _dl double-layer capacity - o₂ oxygen overpotential     

The rate of crystallization of poly(ethylene terephthalate) by differential scanning calorimetry

The value of t_max in differential scanning calorimetry is correlated with the crystallization kinetics of poly(ethylene terephthalate) (PET). The Avrami exponent, n, obtained varies as a result of a change in slope of the curve at the point t_n, a secondary crystallization transition. The plot of t_n vs. t_max shows a linear relationship. The rate of crystallization depends upon both molecular weight and crystallization temperature. Under a nucleation controlling step, the plot of log t_max vs. \documentclass{article}\pagestyle{empty}\begin{document}$ t_{\max } vs.\frac{1}{{T^2 \Delta T}} $\end{document}gives a linear relationship. Theoretical concepts of the treatment are discussed.