The biodegradability of two primary alcohol ethoxylate nonionic surfactants under practical conditions,and the toxicity of the biodegradation products to rainbow trout

A field trial has been performed to measure the biodegradability of two typical alcohol ethoxylate nonionic surfactants, “Dobanol” 45-7 and “Dobanol” 45-11, by dosing them to biological filters in a mixture with domestic sewage. Influent levels were 10 and 25 mg l^?1 of each surfactant and 96–98% degradation was achieved within a temperature range of 5–10°C. The surfactants had no adverse effects on the filters in terms of the usual sanitary parameters (BOD, COD, TOC and ammoniacal nitrogen). Tests on the effluents indicated no residual acute lethal toxicity to rainbow trout Salmo gairdneri).     

水文化研究的现代视野

水文化与人类文明同步。与水文化作为母体文化的传统优势相比,现代水文化研究的冲击力显得极其不足。应该在现代文化的视野下寻找水文化研究更为宽阔的出路。现代水利科技是水文化的主体,水资源短缺的危机为现代水文化提出了挑战;水与经济互动发展拓展了现代水文化的空间;农村饮水安全问题使水文化与人文素质相互渗透;农村水库生活与和谐社会建设为水文化提供了新的诠释。     

计算机模拟溃坝洪水问题的程序设计

随着计算机性能的提高，计算机模拟技术日益复杂，在研究使用计算机模拟洪水的演进，以期给出准确的预警，最大限度减少损失和人员伤亡方面也取得一定进步。本文尝试用MATLAB程序模拟溃坝洪水，并在最后给出一个算例。     

Molecular Diffusion Coefficients of Organic Compounds in Water at Different Temperatures

Molecular (or tracer) diffusion coefficient data were obtained for 2-naphthol, benzoic acid, salicylic acid, camphor, and cinnamic acid in water at temperatures that differ significantly from ambient value. Experimental values were determined for the dissolution of 2-naphthol in water at 283 to 368 K, of benzoic acid in water at 283 to 338 K, of salicylic acid in water at 283 to 343 K, of camphor in water at 283 to 318 K, and of cinnamic acid in water at 283 to 318 K. Empirical correlations are presented for the prediction of molecular diffusion coefficient over the entire range of temperatures studied, and they are shown to predict the obtained data with very good accuracy.     

An experimental and three-dimensional numerical study of natural convection heat transfer between two horizontal parallel plates

In this study, experimental and three-dimensional numerical studies were performed to investigate the effects of plate spacing and temperature difference on natural convection between isothermally heated upward-facing lower horizontal plate and externally insulated horizontal upper plate. Air is used as the heat transfer medium. Rayleigh number varied in the 1108–2.339 × 10⁵ range. Several numerical simulations for three-dimensional steady laminar and turbulent flows heat transfer were carried out using a commercial CFD code Fluent 6.2. Results have shown that there is a good agreement between the numerical and present experimental results as well as with available data in literature.     

Vorticity field structure associated with the 3D Tollmien-Schlichting waves

Details of the vorticity field structure associated with the 3D Tollmien-Schlichting waves have been examined based upon the recent numerical studies of the subject. First, a single obliquet-s wave has been found to have the velocity component parallel to the wave front playing an overall dominant role, in particular, to create the longitudinal vorticity. The so-called Benney-Lin longitudinal vortices are then demonstrated to be, in fact, a minor consequence compared with the localized longitudinal vorticity field and its periodic pumping. Finally, the formation of the longitudinal vorticity field in the fundamental- and subharmonic-mode interactions is explained. The research reported in this paper has been supported in part by Bundesministerium für Forschung und Technologie and by Deutsche Forschungsgemeinschaft. The major part of the paper has been presented at the Third Asian Congress of Fluid Mechanics, 1–5 September 1986, in Tokyo, as a General Lecture by the senior author, FRH.     

Al-4%Cu过饱和合金在强磁场中时效行为

采用差示扫描量热仪分析并结合显微硬度测试、电子探针分析、透射电镜观察研究了10-T稳恒强磁场对Al-4％Cu（质量分数）合金130℃时效过程中各沉淀相析出行为的影响。结果表明：在低温时效初期强磁场的引入加速了铜的扩散，降低了G.P.（Ⅰ）区的溶解激活能，促进其溶解，各沉淀相的析出与溶解温度均向低温处移动，时效进程加快；另外，强磁场时效后沉淀相尺寸减小；施加强磁场试样的硬度明显高于未施加磁场试样的，时效硬化效果加强。     

Neural networks modeling signal responses and taxol production of cultured Taxus chinensis cells induced by bio-elicitor

Quantitatively describing the signal transduction process is important for understanding the mechanism of signal regulation in cells, and thus, poses both a challenge and an opportunity for chemical and biochemical engineers. An artificial neural network (ANN), in which we took the signal molecules as neural nodes, was constructed to simulate the generation of active oxygen species (AOS) in Taxus chinensis cells induced by a bio-elicitor. The relative contents of AOS in cells predicted by the ANN model agreed well with the experimental data and three notable stages of AOS increase were observed from the 3D figure of AOS generation. The robustness of AOS trajectories indicated that signal regulation in vivo was an integral feedback control model that ensured the adaptation of Taxus chinensis to environmental stress. The artificial neural network was able to predict taxol production as well as determine the optimal concentration of oligosaccharides needed for it.     

引滦入唐工程某渡槽裂缝成因及对策分析

针对引滦入唐工程中某渡槽的开裂情况，从渡槽的两个使用状态入手进行分析，考虑按旧规范计算对设计造成的误差，采用大型有限元分析程序分析了渡槽各种工况的运行情况，并根据使用情况分析了开裂原因，提出了加固意见和同类渡槽设计的建议。     

型钢厂试轧美标H型钢性能分析研究

分析了型钢厂试制热轧美标H型钢低温冲击韧性偏低的原因，并在此基础上提出了对生产工艺的优化与改进。