苯菌灵亚慢性毒性试验染毒饲料分析

介绍了苯菌灵在亚慢性毒性试验所用饲料中的液相色谱分析方法,并对该药在染毒饲料中的均一性、稳定性和实际浓度进行了监测。结果表明,该药剂在亚慢性经口毒性试验染毒剂量是准确的。     

木脂素合成中单体的氧化偶联研究简介

木脂素是由两分子苯丙素聚合而形成的一类天然化合物,广泛存在于自然界中,其中大多数木脂素为游离的状态,小部分与糖结合成苷而存在于植物的木部和树脂中,所以称之为木脂素,而最近又在动物体内发现了有别于植物木脂素的哺乳动物木脂素[1].由于大部分木脂素具有很高的抗癌、抗肝炎、杀虫等生物活性,因此被广泛的应用于在医药、农业以及日化等方面,木脂素的合成一直是有机合成中的一个热点[2],而合成木脂素的偶联条件的选择是木脂素合成中起到关键性因素,文章就几种重要木脂素的合成方法中单体的氧化偶联方式进行简单的介绍.     

PIG清焦技术在炼厂加热炉的实践

某厂焦化装置加热炉对流段结焦严重需要清焦,通过比较各种清焦技术的利弊,采用了清焦效果好、对炉管损伤小、工期短、安全环保的PIG清焦技术,清焦后加热炉运行效果良好,延长了装置的开工周期,具有很大的推广价值。     

膜催化技术用于甲烷转化反应的研究进展

介绍了膜催化技术在甲烷转化反应中的应用,这些过程包括甲烷氧化偶联反应制乙烯,甲烷部分氧化制甲醇,甲烷水蒸气重整制合成气等,通过膜催化反应与传统催化反应的比较,揭示了膜催化技术的优点。     

Changes in the energy characteristics of the surface of organosilicate coatings in the course of formation

The influence of the parameters of curing of organosilicate coatings and the degree of completeness of interfacial chemical reactions on the total surface energy, its dispersion and polar components, and the physicochemical and protective properties of coatings is analyzed. The possibility of using organosilicate coatings as easily cleanable materials is determined by the small values of the surface energy and its polar component.     

Role of the unsaturated group in the radiation-induced crosslinking of polyethylene in the presence of chlorotrifluoroethylene

The effect of unsaturated groups on the crosslinking of polyethylene in the presence of chlorotrifluoroethylene (CTFE) has been studied. Butadiene- and isoprene-grafted polyethylenes with high concentrations of unsaturated groups were crosslinked more markedly than the original polyethylenes. The rate of gel formation increased with the increase in the initial concentration of unsaturated group in polyethylenes, while the rate of grafting of CTFE decreased. The concentration of unsaturated group decreased rapidly during the course of the reaction. The rate of decrease in each unsaturated group was in the order, vinylidene > vinyl >trans-vinylene. In the irradiation of polyethylene with a high concentration of unsaturated groups in CTFE, the number of grafted monomers was almost equal to the decrease in numbers of the unsaturated group. These results are discussed in relation to the reaction mechanism and the estimated activation energy of the elementary reaction     

水体中氨氮检测结果影响因素分析

水体中氨氮的污染是世界性的问题,氨氮污染的直接后果是导致水体富营养化,影响渔业生产,严重影响了人、畜饮用水安全,恶化了人类的生存环境,因而准确定量水体中氨氮含量显得尤为重要和紧迫.系统论述了影响氨氮检测结果准确度的因素,以及保证检测结果准确度的方法.     

废陶瓷在水处理中的资源化

陶瓷工业废料废渣日益增多,对城市环境造成压力而且限制了陶瓷工业的可持续发展.归纳了陶瓷废料的来源和分类,掺杂4%田菁粉在800℃下煅烧成功制备了多孔陶瓷,对含Ni废水中Ni的吸附去除率达到85.68%;上述多孔陶瓷的再生可行而且取得了理想的再生应用效果.     

微通道内火焰传播的研究进展

微燃烧器与阻火器淬火单元均为可燃气体燃烧的微通道,目前对微燃烧器的研究较充分,而对阻火器淬火单元的研究较少. 本工作概述了影响火焰在微通道内传播的因素,指出对各因素的研究还需深入,有利于澄清争议;简述了火焰在微通道内传播的数学模型的研究进展,提出微通道内流体流动流型的判定亟需完善;确定在高速爆轰条件下,阻火器内的流动为湍流;推荐将雷诺应力湍流模型与层流有限速率模型结合进行阻火器内高速爆轰火焰传播的数值模拟,推荐采用以密度为基础的算法进行求解;指出了微通道内火焰传播研究的成果与不足,展望了其发展方向.     

Role of the lymphatic system in the transport of absorbed 7,12-dimethylbenzanthracene in the rat

To determine the role of the intestinal lymphatic system in the absorption of a polycyclic aromatic hydrocarbon, 7,12-dimethylbenzanthracene, a radiolabeled preparation of the compound was given by intraduodenal infusion to rats in doses of 10 μg, 10 mg and 20 mg in olive oil solution. The hydrocarbon appeared to be absorbed from the intestine in a fractional manner, ca. 20% of the administered radioactivity being recovered totally in bile and intestinal lymph in 24 hr at all three dose levels. Biliary radiolabel accounted for 75–82% of combined recovery of radioactivity in bile and lymph with all three doses. The recovery of significant amounts of radiolabel in bile before the appearance of isotope in lymph, together with the fact that the biliary radiolabel greatly exceeded at all times the lymphatic recovery of isotope, suggests that an alternative pathway, presumably the portal venous route, is of major importance in the transport of the absorbed hydrocarbon.     

Improvements in the two-parallel-condenser model of the double layer in the presence of organic adsorption

Previous recent attempts by the author for giving a more consistent physical meaning to the two-parallel-condenser model and its implications on the adsorption isotherm behaviour are reviewed. In addition, the displacement of oriented water molecules by the adsorbate is taken into account and the effects of a series capacity are discussed. This allows to consider the original expression for the charge density as a function of potential as an approximation of a model much more complex than that first treated. The new expression for the limiting capacity at maximum coverage still allows a consistent analysis from the corresponding experimental parameters.     

数学建模在材料领域的应用初探

文章探讨了数学建模的主要方法,针对材料的不同应用、用途、评价等实际中采用不同的建模方法,有效的评价材料更加直观、形象和接近事实,为材料应用的工程、实际问题提供较强理论分析和应用的价值。     

法医病理学死亡时间的推断研究进展

死亡时间是从案件发生到尸体检验所经过的时间,通过准确推断死亡时间推断案件的发生时间,并与涉案的人和事密切相关,为案件的侦查与审理提供科学的依据,是法医学研究的一个领域。但由于影响因素较多和技术手段落后等原因,死亡时间的判断不是特别精准,在查阅了近年来国内外学者的先进方法和技术后,文章综述了现阶段此领域的研究现状。     

Influence of shear in the crystallization of polyethylene in the presence of SWCNTs

It is well accepted that due to epitaxy matching, carbon nanotubes are good nucleating agent for linear polyethylene. We demonstrate that not only in the quiescent conditions but also at the relatively low shear rates the presence of single-walled carbon nanotube (SWCNT) accelerates the crystallization kinetics of polyethylene (PE). The influence of SWCNTs on the crystallization kinetics in the quiescent condition is followed with the help of rheological and differential scanning calorimetry studies. The influence of flow on the stretch of the polymer chain is probed using time-resolved small-angle X-ray scattering (SAXS) and is verified with the Deborah number. SAXS data indicates that the strong shearing conditions (shear rate > 50/s for 1 s) are requisite to form shish-kebab structure in the neat polymer. However, for the low shear (shear rate < 50/s for 1 s), the shish-kebab structure that arises due to chain orientation is enhanced in the presence of SWCNTs. The development of oriented structures in SWCNT/PE composites and their absence in the neat polymer under low shear rate indicates that the presence of SWCNTs plays a significant role in the chain orientation. Overall, the results manifest the influence of SWCNTs on chain relaxation of the polymer.     

磨机隔仓板的改进

Ф3．2m×13m水泥磨是我公司生产数量较多的产品，从第一台投产至今，数量已经超过几百台，产量稳定可靠。但从水泥生产厂家反馈的信息来看，这种磨机隔仓板的断裂现象发生得比较频繁，情况严重时甚至投产不到三个月就有篦板断裂事故发生。为此，笔者对原始的隔仓板进行了分析，并进行了设计上的改进，取得了良好的效果。     

脂质体的研究新进展

脂质体作为新型药物载体,在提高药物制剂稳定性及提高药物靶向性等方面有了实质性进展,具有广阔的应用前景,综述了近年来国内外脂质体的制备技术、作为药物载体的应用及最新发展动态。