热熔凝聚法加工农药悬浮剂研究

介绍了采用热熔凝聚法对加工二氯喹磷酸、氟虫睛、乙霉威悬浮剂的试验结果，并测定了制剂的粒度分布、冷贮、热贮稳定性等理化性质。该法工艺简单、加工方便、节省能源、工业上切实可行。     

固相萃取技术在农药残留分析中的应用

固相萃取是一种新型的样品预处理技术，操作简便，节省有机溶剂，易于实现自动化操作，已广泛应用于环境保护、药物检测、食品检验检疫等领域。在农药残留分析中，固相萃取技术的应用还使得提取不同类别农药的选择性增强，样品回收率提高，尤其是结合HPLC—MS、GC-MS、CE-MS等仪器的联合鉴定，可实现自动化分析，能简单、快速、灵敏地提取定量许多物质，从而大大提高了分析效率和精密度，具有广阔的发展前景。     

富集均三甲苯塔的模拟与优化

在满足工艺要求的基础上，通过富集均三甲苯塔模拟与优化给出最佳操作条件，用于指导实际操作和设备改造．优化生产参数。     

Catalytic activities and properties of mesoporous sulfated Al2O3–ZrO2

Mesoporous sulfated Al₂O₃–ZrO₂ (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher Al₂O₃ content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption, transmission electron microscopy (TEM), ²⁷Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed desorption of ammonia (NH₃-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al₂O₃–ZrO₂ samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed reactions.     

可降解聚丙烯发泡塑料初探

开发可降解聚丙烯(PP)发泡制品具有广阔的发展前景。PP自身的化学结构特点使其具有比其它聚烯烃和PS更优异的降解性能。在PP中添加各种光降解剂,或引入光敏基团可以促进PP的光降解性;将其与天然高分子或各种可降解塑料混合也可以有效促进PP的生物降解;将降解和发泡的配方和工艺合理结合以获得光降解性、生物降解性或光 生物双降解的发泡PP制品是完全可能的。     

熔融缩聚法制备聚乳酸

通过熔融缩聚法制备了聚乳酸。探讨了反应温度、催化剂类型及用量、反应时间对聚乳酸的影响，并用红外光谱和1↑H NMR对聚合物进行了表征。结果表明，最佳的反应条件为：聚合时间30h左右、聚合温度160℃、以O．2％的对甲苯磺酸作为酸催化剂、O．5％的氯化亚锡为催化剂、真空度为O—1333Pa；而提高乳酸纯度是制备高摩尔质量聚乳酸的关键条件之一。     

Composition of mixed octadecadienoates via ozonolysis,chromatography and computer solution of linear equations

An approach to the analysis of 55 possible nonconjugated positional isomers of octadecadienoic acid is described and tested with mixtures of individual synthetic methyl esters. In the first example, by ozonolysis a sevencomponent mixture consisting ofcis,cis 5,12-, 6,10-, 6,11-, 6,12-, 7,12-, 8,12-, and 9,12-octadecadienoates was converted to aldehydes, aldehyde-esters and dialdehydes. These fragments were separated on a 50 m×0.2 mm free fatty acid phase (FFAP) vitreous silica capillary column. Equations for an arbitrarily restricted 12×15 matrix of linear simultaneous equations and a computer solution of the matrix provided the composition of the initial methyl octadecadienoate mixture. The power and significance of this method became apparent with the observation that only two of the seven isomers in the known mixture were resolved as single peaks by state-of-the-art capillary gas chromatography, but all seven were identified and estimated with acceptable error by the ozonolysis-capillary gas chromatography-computer procedure. In a generalized approach to the analysis of the 55 possible nonconjugated isomers, a computer program selects the appropriate matrix of linear simultaneous equations based on the aldehyde data supplied by the analyst. Twenty of 21 combinations of seven isomeric esters taken five at a time have been analyzed to assess the efficiency of the method. To illustrate applicability at this stage of development, the method has been used to analyze the diene products of the hydrazine reduction of γ-linolenic acid and the diene products from the biological desaturation of isomeric monoenes. The possibility of distinguishing geometric and positional isomers of 18∶2 has been opened by the observed separation ofcis-andtrans-unsaturated aldehydes and aldehyde-esters. Presented in part at the 16th World Congress of the International Society for Fat Research, October 4–7, 1983, in Budapest, Hungary, and at the American Oil Chemists' Society Meeting, May 15, 1986, in Honolulu, Hawaii.     

基于CFD软件模拟精度与可信度影响因素分析

CFD软件广泛用于流体流动与传热的模拟。但CFD软件是一个黑盒子,良好的人机界面、众多参数基于经验值设定以及二次开发知识的相对薄弱,使得软件使用者对于数据流向并非完全清楚,导致模拟过程的盲目性以及模拟结果的差异。模拟结果的准确与否关系到软件的可信度以及软件的推广应用程度。针对如何有效利用当前模拟软件,如何最大限度地发挥其计算性能,并将计算结果精度及可信度进一步提高,提出了一些看法。     

Fabrication and amplification of Rhodamine B‐doped step‐index polymer optical fiber

A step‐index polymer optical fiber (SI POF) containing Rhodamine B in poly(methyl methacrylate) (PMMA) has been fabricated by a preform technique. Fluorescence of different fiber lengths were observed and discussed. A high gain (23 dB) for a SI POF with 60‐cm length, 400‐μm diameter was obtained. The Rhodamine B content of the doped SI POF is 5 ppm‐wt. The signal wavelength providing the highest gain for a 60 cm SI POF is around 630 nm, and the optimum fiber length is about 60 cm at 10 kW launched pump power. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 681–685, 2004     

石灰石在煤气化过程中的催化和固硫作用

基于CaO在煤气化中的催化和固硫作用,以及石灰石加热分解的性质,石灰石有可能作为煤气化过程中的催化剂和固硫剂。本文根据国内外对石灰石在煤燃烧和煤气化中作用的研究,从石灰石结构、Ca/C,Ca/S,可能的反应机理等几个方面进行了介绍和分析,并指出需进一步研究的内容。