浅析AC发泡剂生产的碱耗和省碱技术

本文概况了尿素法AC发泡剂的生产过程中中间产品的流失途径及副反应的产生原因对AC收得率(以碱计算)的影响以及省碱技术进行了分析.     

气相法改性纳米二氧化硅表面

采用硅烷偶联剂A-151处理的纳米二氧化硅粒子，具有良好的疏水性，并且反应副产物没有腐蚀性，有利于保护设备和环境保护。分别用表面羟基数、亲油化度等性能来表征改性纳米二氧化硅的效果。红外光谱分析表明A-151确实已经和纳米二氧化硅表明的羟基发生了化学反应，通过透射电镜研究发现改性后纳米二氧化硅在乙醇中达到纳米级的分散。     

An Attractive Synthetic Approach to Methyl Formate from Methanol via Methyl Nitrite

Catalytic synthesis of methyl formate has been investigated by a novel route starting from methyl nitrite in vapor phase. The acidic sites of the catalysts play a crucial role for the catalytic activity and the selectivity of formation of methyl formate. The H-Y zeolite catalyst gave higher yield and selectivity of the target product. This study provides a new approach for the synthesis of methyl formate from methanol via methyl nitrite.     

改性木粉/PVC复合材料的研究进展

概述了PVC木塑复合材料的发展和背景与性能。简述了木质材料的性质和木粉改性的方法,如物理方法和化学方法。介绍了木塑复合材料的生产流程、成型方法(模压成型、挤出成型、注射成型及其成型设备,讨论了对工艺参数的一些要求。指出目前国内PVC木塑复合材料发展存在的一些问题,并指明了PVC木塑复合材料的应用前景。     

氧化物纤维/氧化物陶瓷基复合材料研究概述

氧化物纤维，氧化物陶瓷基复合材料可以在高温氧化环境下长时间工作，是最有发展潜力的高温结构陶瓷材料之一。决定氧化物纤维，氧化物陶瓷基复合材料性能最主要的2个因素是氧化物纤维的性能和界面材料的组成与结构。笔者介绍了氧化物纤维和界面材料的发展，以及界面材料涂覆方法，并探讨了氧化物纤维，氧化物陶瓷基复合材料的发展趋势。     

联苯型双醚二酐的合成及其表征

以4,4′二羟基联苯(联苯二酚)和N甲基4硝基邻苯二甲酰亚胺为主要原料,在非质子性溶剂中,经缩合得到联苯双醚二酞酰亚胺,再经水解、酸化、脱水等工艺制得联苯型双醚二酐(BPEDA)。通过红外光谱对产品进行了表征,结果符合要求。该单体与4,4′二氨基二苯醚(ODA)在N,N二甲基乙酰胺(DMAc)中缩聚所得聚酰胺酸特性粘度为0.72dL/g。将PI制成薄膜,室温下拉伸强度为98.5MPa,成膜性能良好。     

Engineering a pharmacologically superior form of leptin for the treatment of obesity

Leptin plays a central role in the homeostasis of body weight through its regulatory effects on appetite and energy expenditure, yet in trials as a therapeutic agent for the treatment of obesity in humans it has been disappointing. The poor clinical efficacy of leptin results from its short circulating half-life, low potency and poor solubility, necessitating large and frequent doses to obtain even modest clinical benefit. Engineered Fc-leptin immunofusins, consisting of the Fc fragment of an immunoglobulin gamma chain followed by leptin, exhibit improved pharmacological properties with very consistent and potent biological activities. Furthermore, in extending the circulating half-life of the protein in vivo from a few minutes for leptin to many hours for Fc-leptin, these proteins have the potential to reduce drastically the dosage and frequency of administration required to obtain clinical benefit. The results of this study show that the engineered leptin immunofusins described here have significantly enhanced pharmacological properties in comparison with the recombinant leptin that was used in clinical trials. As such, they could represent an important step towards a therapeutically superior form of leptin if the disappointing performance of leptin in early clinical trials was due to its poor pharmacological properties rather than any conceptual weakness in the strategy of using leptin for the treatment of obesity and its related disorders.     

甲醇/正己烷的渗透汽化分离的研究 Ⅰ.渗透汽化膜的研制

本文研制了从甲醇／正己烷体系中分离甲醇的渗透汽化复合膜ＣＡ／ＰＡＮ（ＰＥＳ）、ＰＶＡ／ＰＡＮ（ＰＥＳ）。实验证明膜对该体系有较高的选择分离性和良好的渗透性，当进料甲醇浓度为３％时，渗透通量Ｊ≈０．６００ｋｇ／ｈ·ｍ２，分离因子α→∝。本文还考察了不同操作条件对膜分离性能的影响及膜的稳定性和均匀性。     

Morphologic study of electrochemically formed lead dioxide

Various electrochemical methods with different conditions were used to prepare lead dioxide (PbO₂). The observation revealed that the morphology of deposited PbO₂ could be controlled by simply changing deposition parameters. Under the condition of oxygen evolution, which dominates the electrode process, uniformly distributed high porous structured PbO₂ was formed. The results indicated that large current density or high potential polarization should be one of the most important and necessary factors for forming high surface area PbO₂ deposit. Only β-PbO₂ was identified by X-ray diffraction measurement for the deposit prepared by present methods and solution. One potential application of this method is to prepare nanoscaled PbO₂ parallel lines.     

QH-2型扁环填料的流体力学和传质性能研究

在内径60 0填料塔中 ,用空气 富氧水系统对3 8和5 0QH 2型扁环填料的流体力学和传质性能进行了研究 ,得出计算其压降、液泛气速和传质单元高度的关联式。并与3 8鲍尔环、5 0鲍尔环和3 8环矩鞍填料进行了比较 ,结果表明 ,QH 2型扁环具有优良的流体力学和传质特性。