HT—1型钛材焊缝坡口清洗膏的研制及其效果分析

本文为钛设备特殊部位或结构的清洗而研制出适合于爆缝坡口的清洗膏，实验证明，该清洗膏能有效地清除钛材料坡口氧化膜，提高焊接质量。     

建筑陶瓷生产用印膏的研制

利用羧甲基纤维素钠（Na—CMC）、甘油、乙二醇和纯净水等为主要原料制备建筑陶瓷生产装饰用印膏，实验研究了工艺因素对印膏粘度和印刷性能的影响，优化出适合生产使用的印膏配方。结果表明：当Na-CMC的加入量在1．75g～2．25g之间，甘油15g，乙二醇20g，纯净水65g所制备的印膏具合适粘度和良好的印刷性能。     

高效液相色谱法测定剑麻皂苷元的含量

以乙腈-水(90∶10)溶液为流动相,检测波长为225 nm,建立了高效液相色谱法测定剑麻皂苷元的方法。结果表明,剑麻皂苷元在4.8²4μg范围内线性相关,回归方程:Y=6 186.312 5X-14 660.1,R2=0.985 48。精密度实验RSD为0.013%,稳定性实验说明在11 h内稳定,重复性实验RSD为0.062%,加标回收率实验平均回收率为96.2%,样品中剑麻皂苷元的含量为0.571 2 mg/g,此方法操作简便、准确、可靠,可为剑麻皂苷元的质量检测提供依据。     

无铅焊膏在电子封装组装中的应用

随着人们对环境的日益重视和电子封装组装焊接技术的发展，合金焊膏的无铅化和质量的要求越来越高，开发无铅、无毒焊膏成为焊膏开发的重要方向，本文论述了几种无铅焊膏Sn-Ag系，Sn-Bi和Sn-Zn系的特点，同时，也检测和评价了一种Sn-Ag免洗焊膏，其绝缘抗阻性，抗腐蚀性，产品清洁度和产品可靠性等均符合要求。     

剑麻麻膏水解工艺研究

以剑麻麻膏为原料，水为溶剂，采用浓硫酸酸解法制备水解物，考察了水解时间、硫酸质量浓度、麻膏与浓硫酸质量比对水解收率及水解物含量的影响。以高效液相色谱为检测手段，通过单因素和正交设计实验确定了水解的最佳工艺条件：水解时间8h，硫酸质量浓度15%，麻膏与浓硫酸质量比1∶1。在此条件下水解物收率68.56%，水解物含量12.55%。     

自动落膏系统改造

分析了原落膏系统的存在问题，运用新的思维进行有针对性的设计，解决了生产中存在的实际问题。     

水葫芦叶绿素面膜膏的研制

文章利用水葫芦叶固有鲜亮绿色富含叶绿素这一特性,在最佳工艺条件下提取叶绿素来制备营养保湿面膜膏。以较简单的配方为原则,选择在面膜膏中应用较为广泛的原料进行叶绿素面膜膏的试制。通过正交实验,找出一个具有最佳面膜膏的基础配方来调配面膜膏,并对该产品的理化指标进行检测和产品使用效果进行评价。     

稳定的三相混合体系的生成研究—用广东白瓷土制备清洁膏

我们实验室已成功制备出由白瓷土、油性功能组份及活性物质水溶液组成的高稳定性膏状清洁上光剂。本文结合制备工艺条件,通过对产品稳定性影响的实验结果,讨论了如何获得高分散、高稳定的油-水-固三相体系的一些规律。     

氟石膏的综合利用

对氢氟酸生产中的副产品氟石膏的性质进行了介绍，综述了氟石膏目前在我国的综合利用现状，并对未来氟石膏的利用提出了展望。     

关于新标准的几点看法

GB8372-2001是在GB8372—1995基础上修订的，但笔者认为仍存在如下不便操作之处。     

木质素/热塑性塑料复合材料界面增容的研究进展

将木质素作为一种有机颗粒填料添加到热塑性塑料中,可解决造纸黑液资源化利用、石油原料日渐紧张以及环境污染加剧等严峻问题。而木质素与热塑性塑料之间相容性直接影响木质素在塑料工业中的应用与发展。首先简要概述了木质素结构与性质和木质素/热塑性塑料复合材料的性能分析,然后系统地阐述国内外研究木质素/热塑性塑料复合材料界面增容方法及其原理;增容方法按添加相容剂、改性木质素和改性塑料进行归类,并对3种增容方法进行比较分析;接着综述了木质素复合材料中增容方法的交叉复合使用;最后对未来木质素/热塑性塑料复合材料界面增容的研究方向以及思路进行了展望。     

Pd-Pb/SiO2催化高浓度乙烯基乙炔加氢合成丁二烯

研究了硅胶负载钯铅双金属催化剂催化高浓度乙烯基乙炔加氢合成丁二烯过程。结果表明,加入适量的铅可起到分隔钯纳米粒子,阻碍钯纳米粒子团聚的作用,从而提高催化剂的催化活性,最佳Pb/Pd摩尔比为0.2。继续提高Pb/Pd摩尔比时,会生成铅钯合金相,造成催化剂活性降低。X射线光电子能谱结果表明,催化剂的催化活性与Pd 3d的电子结合能呈正相关关系。制备催化剂过程中,还原温度对催化剂的结构和催化性能影响显著。在350℃下还原得到的催化剂中金属氧化物还原不彻底,催化剂活性较低;还原温度为450℃时,则会引起钯纳米粒子烧结,造成催化剂的催化活性和对丁二烯的选择性同时降低;催化剂的最佳还原温度为400℃。在40℃催化乙烯基乙炔反应40 h后,积炭造成催化剂的孔道堵塞,催化剂失活。因此,需要进一步开展改善催化剂的抗积炭能力和使用寿命方面的研究。     

Natural products phytotoxicity A bioassay suitable for small quantities of slightly water-soluble compounds

A large variety of secondary metabolites that can inhibit germination and/or seedling growth are produced by plants in low quantities. The objective of this study was to develop a bioassay capable of reliably assessing reductions in germination percentage and seedling length of small-seeded plant species caused by exposure to minute quantities of these compounds. The germination and growth of alfalfa (Medicago saliva), annual ryegrass (Lolium multiflorum), and velvetleaf (Abutilon theophrasti) were evaluated against six known phytotoxins from five chemical classes; cinmethylin (a herbicidal cineole derivative) was selected as a comparison standard. Each phytotoxin, dissolved in a suitable organic solvent, was placed on water-agar in small tissue culture wells. After the solvent evaporated, imbibed seeds were placed on the agar; after three days, germination percentages and seedling lengths were measured. Compared to a commonly used filter paper procedure, this modified agar bioassay required smaller quantities of compound per seed for comparable bioassay results. This bioassay also readily permitted the measurement of seedling length, a more sensitive indicator of phytotoxicity than germination. Seedling length decreased sigmoidally as the toxin concentration increased logarithmically. Phytotoxicity was a function of both compound and plant species. Cinmethylin, a grass herbicide, reduced the length of annual ryegrass seedlings by 90–100%, whereas that of alfalfa and velvetleaf was inhibited slightly. The agar bioassay facilitated the rapid and reliable testing of slightly water-soluble compounds, requiring only minute quantities of each compound to give reproducible results.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Oxidation of acylglycerols and phosphoglycerides by soybean lipoxygenase

Lipoxygenase (EC 1.13.11.12) catalyzes the incorporation of oxygen into polyunsaturated fatty acids, resulting in the formation of their corresponding hydroperoxides. The ability of a commercial preparation of soybean (Glycine max L. Merr.) lipoxygenase to catalyze the oxidation of acylglycerols and phosphoglycerides was investigated. The oxidation rate of trilinolein increased nearly 100% when 5 mM deoxycholate was added to the reaction medium. With further increases in the concentration of deoxycholate, the oxidation rate decreased slightly. The pH profile of trilinolein oxidation was bell-shaped. The rate of oxidation was maximal at pH 8, and it decreased to near zero at pH 5 and pH 11. Even under optimal conditions, the rate of trilinolein oxidation was only 3% of that of linoleic acid, and analysis of time course data showed that, at most, 15% of available linoleate was oxidized. In contrast to the slow rate of trilinolein oxidation, tested phosphoglycerides and diacylglycerols were oxidized at moderate rates. The rate of phosphoglyceride oxidation depended upon the structure of the polar head group and varied between 7–28% of the rate of linoleic acid oxidation. Diacylglycerols reacted at a rate that was 40% of that of linoleic acid. Analysis of the time course of 1,3-dilinolein oxidation showed that as much as 67% of the available linoleate could be converted to the corresponding hydroperoxide. Analyses by high-performance liquid chromatography revealed that more than 20% of the 1,3-dilinolein was converted to unidentified products that are not hydroperoxides.     

合成气经二甲醚羰基化及乙酸甲酯加氢制无水乙醇的研究进展

合成气经二甲醚羰基化及乙酸甲酯加氢路线制无水乙醇技术因具有诸多优点而备受市场关注。本文综述了该工艺的核心反应机理和最近研究进展。主要探讨了丝光沸石8元环与12元环对羰基化反应的作用。阐明了如何通过调变丝光沸石8元环与12元环的活性位来提高羰基化催化剂的活性与稳定性。评述了铜纳米粒子的粒径、分散度以及Cu⁺与Cu⁰的分布等特点对铜基催化剂加氢催化活性的影响。提高乙醇选择性与催化剂稳定性是该研究的重点与难点。指出羰基化催化剂的优化重点是调变丝光沸石的孔道结构,加氢催化剂的发展方向是构建高分散度的铜纳米粒子,并在反应过程中保持稳定。     

Trapping the western pine beetle at and near a source of synthetic attractive pheromone Effects of trap size and position

Western pine beetles were caught on unbaited sticky traps placed near a source ofexo-brevicomin, frontalin, and myrcene. Size of trap, distance and direction from the source of attractant, and height from the ground were varied. Significant differences in trap catch were observed in relation to each of the variables. Traps close to the source of attractant caught more beetles than traps farther from the source. Traps downwind of the source of attractant caught more beetles than did upwind traps. More males than females were trapped close to the source of attractant.Based in part on a thesis submitted by the senior author to the University of California, Berkeley, California, in partial fulfillment of the requirements for the degree Master of Science in entomology, December 1976. These studies were supported by the U.S. Forest Service and in part by the Rockefeller Foundation and a joint grant (NSF GB-34718/BMS 75-04223) from the U.S. National Science Foundation and the U.S. Environmental Protection Agency to the University of California. The findings, opinions, and recommendations are not necessarily those of the University of California or the funding agencies.Trade names and commercial enterprises or products are mentioned solely for information and do not constitute endorsement by the U.S. Department of Agriculture or University of California.     

Kondensation von Dampfgemischen nicht mischbarer Flüssigkeiten

Condensation of Vapour Mixtures of Immiscible Liquids In contrast to the condensation of pure vapours and vapour mixtures of miscible liquids, the condensation of vapour mixtures forming immiscible or only partly miscible condensates is still poorly understood. Models describing heat transfer in the latter kind of condensation deviate so much from one another, not only quantitatively but also qualitatively, that reliable design of condensers is impossible. The reason lies primarily in the variety of flow patterns of two‐phase condensates, which range from pure droplet to pure film condensation. This paper surveys literature reports of the flow patterns and heat transfer occurring during condensation of vapour mixtures in the miscibility gap of their liquids. Qualitative knowledge in this condensation area is shown to be satisfactory. Several models have been proposed for heat transfer. However, the heat transfer coefficients obtained from these models differ too much from one another to allow one to choose the “best” correlation. Our own experiments with a eutectic benzene–water mixture on a vertical tube show that the calculation scheme proposed by Hoon and Burnside leads to acceptable results.     

Effect of structural characteristics on impact breakage of agglomerates

The mechanical properties and evolved structure of agglomerates depend strongly on the manufacturing method. There is a great interest in finding a simple way of establishing a rank order in their processing behaviour, e.g., the ease with which they could be dispersed in fluids. For this reason, the breakage propensity of two types of detergent agglomerates produced by different processes but with the same formulation has been evaluated under different conditions by impact testing with a view to diagnose differences in mechanical properties and structure arising from their manufacturing method. The effects of impact velocity, agglomerate size, impact angle, fatigue, humidity, and temperature have been analysed. Both samples show extensive plastic deformation due to the elongation and eventual rupture of the interparticle bridges, especially for the humidified samples. Reducing the temperature increases the extent of breakage substantially. The impact test results of samples kept at −20 °C show brittle failure mode, whilst those of oblique impacts at 45° and ambient conditions show a semi-brittle failure mode by shear deformation. Drying strengthens the agglomerates presumably due to the solidification of bridges. In contrast, humidifying the granules decreases their strength. A general comparison of the impact test results of both samples for different feed sizes shows that, due to the structural differences, the breakage trend of these two types of agglomerate varies with increasing agglomerate size.     

Variation of Brominated Indoles and Terpenoids Within Single and Different Colonies of the Marine Bryozoan Flustra foliacea

The variation of the brominated indole and diterpenoid content within single and different colonies of the bryozoan Flustra foliacea was investigated. The secondary metabolite profile and concentrations of individual components of F. foliacea samples were established using GC-MS. Samples from 17 different collecting sites were analyzed. The alkaloid and diterpene composition of F. foliacea varied greatly depending upon the site of collection. Investigation of F. foliacea samples from a single site (Helgoland, North Sea) over a period of time showed that the alkaloid and diterpenoid profile remained constant, however concentrations of individual components varied significantly. The alkaloid and diterpenoid composition of different segments of a single colony was found to be constant. Only small differences could be detected in the essential oil composition of different colonies and segments of single colonies of F. foliacea. Two of the F. foliacea alkaloids were found in the gastropods Hydrobia ulva and Gibbula cinerea, and one alkaloid in the common starfish Asteria rubens, all collected from the surface of the bryozoan.     

Breakage patterns of agglomerates

The experimental information available in the literature regarding the patterns of breakage of agglomerate materials is scarce, particularly in dynamic loading. The primary objective of this paper is to present our findings on the breakage patterns of the agglomerates and the interparticle bond. A high-speed digital video imaging technique is used here to gain an insight into the impact behaviour of individual agglomerates against a target plate. Several breakage patterns are observed. Agglomerates may suffer localised damage only, with the disintegration of the damaged zone into very fine debris, or localised damage combined with fracture. The frequency of occurrence of these patterns depends on the impact velocity and agglomerate structure. The pattern of breakage affects significantly the size distribution of the impact product. An investigation of the breakage of individual interparticle bonds is also presented. Two forms of failure are observed, internal (cohesive) and interfacial (adhesive) failure. The morphology of the fractured surface depends greatly on the type of breakage. Internal breakage shows irregular surfaces due to crack jumping, whereas interfacial failure produces clean, smooth fracture surfaces. These observations should provide the necessary foundation for the development of a fundamental model of agglomerate breakage.