农药的科学使用问题与农药应用工艺学

作者简要评述了农药与农药使用技术同步发展的历史。对早期无机农药时代以及后期有机合成农药时代开发的农药的显然相反的物理化学性质进行了毒理和使用方面的比较,认为农药的不良副作用是由于有机合成农药的高亲脂性和高的油/水分配系数所引起,并从而产生了有机合成农药在生物圈中的富集现象以及对环境质量的冲击。经过长期的多学科合作研究,由此诞生了农药应用工艺学,其目的是为了解决农药的不良副作用所产生的各种问题。本文简要介绍了农药应用工艺学的科学范畴及相关科学领域的研究内容和发展现状。     

Giant cell reaction against the laminated membrane of echinococcus cysts in reindeer lungs.

In 23 pairs of lungs from reindeer two to five years of age, two types of hydatid cysts of Echinococcus granulosus were found: typical well-developed cysts and collapsed degenerated cysts.Collapsed cysts were found in 13 pairs of lungs, well-developed in nine pairs, while both types of cysts were found in one pair of lungs.A giant cell formation was present in the innermost zone of the surrounding adventitial membrane of both collapsed cysts and well-developed cysts. The giant cell reaction seemed to be induced by and directed against the laminated membrane. In the areas of the cysts where the laminated membrane showed a close contact with the adventitial membrane, the giant cells seemed to be actively engaged in the inflammatory process. On the contrary, in the areas of the cysts where the laminated membrane had lost contact with the adventitial membrane, the giant cells were degenerated or necrotic, and the space between the membranes was filled with necrotic cells. In cases where the laminated membrane had been pronouncedly disintegrated, the giant cells were also necrotic or nonexistent.The giant cell reaction which was found even in comparatively young fertile cysts suggests that the reindeer variant of E. granulosus, if such exists, is not especially well-adapted to the reindeer as its intermediate host.     

Advances in bioherbicide formulation

Formulation of a bioherbicide ideally should result in a product that has low cost, long shelf-life, ease of application and efficacy. Formulation persists as a constraint to commercial development of many potential bioherbicides often because dew dependence in fungi limits their efficacy under dry-land conditions. This has not been a problem with several commercial bioherbicides because they are used in irrigated systems or applied as wound inoculations. Thus, reduction in dew dependence is a principal aim in the formulation of many potential bioherbicides. In the present paper, formulation research attempting in part to overcome this problem via the development of novel solid and liquid formulations is described. Solid formulations typically must be able to survive in the field and await suitable conditions before becoming activated. Liquid formulations have the potential to produce infections soon after application provided they remain moist on the target plant surface. Several attempts to improve water-holding capacity in liquid formulations have been examined. The use of multiple emulsions of water in oil in water has recently shown promise.     

拆装次数对螺钉连接的木塑构件机械性能的影响

螺钉连接是木塑复合材料构件的一种重要的连接方式,它在反复拆装后能否保持其原用强度尚有待于研究.笔者通过对L型和T型木塑构件,经不同拆装次数的结构强度和握钉力试验,得出了拆装次数与木塑构件强度的基本关系.     

稻壳-聚乙烯复合材料经历自然老化后的性能变化

稻壳粉被广泛地应用于聚合物复合材料,但对这些复合材料的耐老化性能研究得还很少。本文研究了两种稻壳粉/聚乙烯(RH-PE)复合板经过两年室外自然老化以后的性能变化。试件的抗弯强度和弹性模量没有变化。但在试验结束后试件的亮度增加了23%以上,总色差变化9个单位以上,意味着消费者当初挑选的颜色发生了明显变化。傅立叶红外(FTIR)和X射线光电子能谱(XPS)分析显示,试件表面发生了氧化反应,老化后红色板材产业明显的C=O峰,但黄色板材的C=O峰并没有明显变化。两种板材都显示木素纤维素减少和聚乙烯的无定形区域减少。图7表4参16。     

基于LM35和W78E52B的数字温度计的设计

基于LM35传感器设计了数字显示的测温系统。介绍了该系统的构成、基本原理及软、硬件设计，讨论了LM35的温度特性。结果表明：该系统实际测温范围为0～100℃，3位整数显示，测温相对误差为±1．0％。     

三种豆科植物种子萌发特性的研究

通过温度、光照、浸种时间及发芽床对3种豆科植物种子萌发影响的研究.结果表明:绿豆种子萌发温度以15～25℃为最佳;阴暗条件比光照条件下萌发速度更快;浸种6～10 d可极显著地提高发芽数;发芽床以纸上和纸间为最佳.大豆种子萌发温度以20℃为最佳;阴暗条件比光照条件下萌发速度更快;浸种6 d可显著地提高发芽数;发芽床以黄壤土为最佳.豇豆种子萌发温度以15℃为最佳;浸种2～3 d可显著地提高发芽数,阴暗条件比光照条件下萌发速度更快,发芽床以黄壤土为最佳.     

木塑复合材料的应用及其发展前景

介绍了木塑复合材料的成分、加工工艺，该材料的适用范围及其力学性能，以及国内外木塑复合材料制品的发展现状和市场前景，为加快我国木塑复合材料产业的发展，提出了三点意见。     

超临界干燥制备木材-SiO2气凝胶复合材料及其纳米结构

采用溶胶-凝胶法和超临界干燥技术制备了木材-SiO2气凝胶,应用XRD、SEM、TFM等方法对气凝胶样品和木材-SiO2气凝胶复合材料的结构和物理性能进行了表征。结果表明：所制备SiO2气凝胶是连续网络的非晶态纳米多孔固体,其基本粒子的平均直径17～9．6nm,SiO2气凝胶与木材有良好的结合并保持木材的空隙结构。     

VARTM工艺中纤维渗透率的测量方法研究

测量纤维增强体渗透率的重要性在于:一方面它控制充模时间,从而与树脂的固化动力学一起影响模具设计和注射口、排气口的位置,是数值模拟所需的关键参数;另一方面,它决定流动特性,控制树脂对纤维束的浸渍方式,是获得高品质制品的关键。笔者以平流法为基础,基于流体动力学原理,给出一维单向渗透率和二维径向渗透率的计算方法,并通过实验测量了一维单向渗透率值和二维径向渗透率值。结果表明:测量树脂对亚麻纤维织物的一维单向渗透率值时,渗透率值呈先增大后减小再增大的趋势,测量树脂对亚麻纤维织物的二维径向渗透率值时,两个坐标轴的轴向渗透率值大小不等,树脂在亚麻纤维织物内的流动是一个从非稳态到稳态的过程。