正交设计方法在消声器设计中的应用

正交试验设计是研究多因子试验问题的重要数学方法,本文将该方法应用于汽车消声器的参数设计中,以正交表来安排多因素试验,不但试制出了性能优良的消声器供汽车使用,而且找出了影响该种结构消声器性能的主要因素,取得了良好的效果。     

大连星海湾水质预测

建设马栏河污水处理厂是改善大连市南部沿海环境的重要措施。本文运用浅海潮波方程和平流扩散方程进行海域水质预测,结果表明：该污水处理厂建成后,星海湾海域水质将有很大好转,达到国家二级标准。     

降水的同位素组成中令人难以捉摸的气候信号

降水的氢、氧同位素组成中包含有气候信号。降水中的两类气候信号表现为降水的同位素组成与温度和降水量之间有相关关系。在极地大陆地区，温度信号最强烈；在热带地区，降水量信号最强烈，在温带地区，这两种信号共存，从而使气候信息的解释比较困难。**对长期收集降水同位素数据的8个3也区的研究表明，降水同位素组成与气候信号之间的相关关系通常局根于一年中的某些季节。降水量与同位素或温度与同位素之间只在一年中的一定季节里保持良好的年间关系。而在逐年比较的基础上，大多数地区的全年尺度的相关关系则比较差。对纽约州东南部连续7年收集的各次降水的详尽分析表明，该区降水的同位素组成与温度和降水量乏间分别在在着年间的相关关系，但只限于一年中的特定的几个季节。1月至4月温度信号最强烈；5月至8月降水量信号最强烈；9月至12月未观测到单一的气候信号。春季改变暴风雨走向轨迹的大气环流模式，可极有效地解释1月至4月的温度信号。夏季大气环流模式所确定的降水期间的锋面位置，可极有效地解释5月至8月的降水量信号。     

Mycorrhizal mediation of plant response to atmospheric change: Air quality concepts and research considerations

The term 'global climate change' encompasses many physical and chemical changes in the atmosphere that have been induced by anthropogenic pollutants. Increases in concentrations of CO2 and CH4 enhance the 'greenhouse effect' of the atmosphere and may contribute to changes in temperature and precipitation patterns at the earth's surface. Nitrogen oxides and SO2 are phytotoxic and also react with other pollutants to produce other phytotoxins in the troposphere such as O3 and acidic substances. However, release of chlorofluorocarbons into the atmosphere may cause depletion of stratospheric O3, increasing the transmittance of ultraviolet-B (UV-B) radiation to the earth's surface. Increased intensities of UV-B could affect plants and enhance photochemical reactions that generate some phytotoxic pollutants. The role of mycorrhizae in plant responses to such stresses has received little attention. Although plans for several research programs have acknowledged the importance of drought tolerance and soil fertility in plant responses to atmospheric stresses, mycorrhizae are rarely targeted to receive specific investigation. Most vascular land plants form mycorrhizae, so the role of mycorrhizae in mediating plant responses to atmospheric change may be an important consideration in predicting effects of atmospheric changes on plants in managed and natural ecosystems.     

The impact of local elites on disaster preparedness planning: the location of flood shelters in northern bangladesh

Disaster relief and preparedness organisations are concerned with allocating scarce resources in unstable environments, such as those prone to flooding and river erosion. The need to understand the role of powerful elites in such disaster prone environments is illustrated through an analysis of the actual location decisions and biases involved in siting four flood shelters in four communities in northern Bangladesh. The previously unrecognised implications of the location biases for employment, shelter, access and the utilisation of the flood shelter by the powerless people in the target group demonstrate the need for disaster organisations to include an analysis of the local power structure in project preparation and appraisal.     

波兰煤炭脱硫的经济与环境问题

论述了波兰含硫煤燃烧的生态,经济条件的技术特征,详细地分析了提高煤炭价格与煤质特性(发热量、灰分)的关系。文中还强调正确解决波兰的生态、环保问题,不仅煤炭要脱硫,而且要采用煤炭燃烧的新工艺,大力发展洁净煤技术。     

土壤毛管渗滤系统在浙江湖州某区新农村示范工程中的应用

针对浙江湖州某区生活污水的特点，分析了国内外生活污水处理的各种常规工艺，以采用先进的土壤毛管渗滤处理技术为主，结合能耗很低的微动力生化预处理和人工生态塘处理技术，取得了良好的处理效果。并详细介绍了土壤毛管渗滤处理系统的组成、各个处理单元的设计参数，分析总结了设计工艺的特点。     

Optimizing microwave-assisted solvent extraction (MASE) of pesticides from soil

Microwave-assisted solvent extraction (MASE) was investigated as an alternative for extraction of parathion (O,O-diethyl O-4-nitrophenyl phosphorothioate), methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), p,p'-DDE [1,1'-dichloro-2,2-bis(4-chlorophenyl)ethane], hexachlorobenzene (HCB), simazine (6-chloro-N2,N4-diethyl- 1 ,3,5-triazine-2,4-diamine) and paraquat dichoride (1,1'-dimethyl-4,4'-bipyridinium) from two different soils and from an earthworm-growing substrate. The matrices were fortified with 14C-radiolabeled pesticides and extracted with various solvent systems under different microwave conditions. Recoveries of more than 80% could be obtained depending on the used microwave conditions and solvent, except for paraquat whose recovery was generally less efficient. Thus, MASE can be successfully used to extract pesticides from environmental and biological samples and could be a viable alternative to conventional extraction methods. The technique uses smaller amounts of organic solvents, thereby minimizing the costs of the analysis and the disposal of waste solvent.     

Euglena gracilis as a model for the study of Cu2+ and Zn2+ toxicity and accumulation in eukaryotic cells

We have observed the effect of copper and zinc on the biology of Euglena gracilis. The cells displayed different sensitivities to these metals, as the apparent LC50 for Cu2+ was 0.22 mM, and for Zn2+ it was 0.88 mM. While Zn2+ was able to increase cell proliferation even at 0.1 mM, the minimal CuCl2 concentration tested (0.02 mM) was sufficient to impair cell division. Higher concentrations of these metals not only inhibited cell division in a concentration-dependent manner, but also interfered with the metabolism of E. gracilis. A higher accumulation of proteins and lipids per cell was observed at the DI50 concentration for metal-treated cells. These results suggest that the test concentration of both metals leads to a failure in completing cell division. Ultrastructural analysis indicated a chloroplast disorganization in copper-treated cells, as well as the presence of electron dense granules with different shapes and sizes inside vacuoles. Microanalysis of these granules indicated an accumulation of copper, thus suggesting a detoxification role played by the vacuoles. These results indicate that E. gracilis is an efficient biological model for the study of metal poisoning in eukaryotic cells. They also indicate that copper and zinc (copper being more poisonous) had an overall toxic effect on E. gracilis and that part of the effect can be ascribed to defects in the structure of chloroplast membranes.     

动物蛋白资源大瓶螺的开发利用研究 Ⅲ.大瓶螺作动物蛋白饲料的食物链开发利用

为开发利用动物蛋白资源大瓶螺,1985年以来分别开展了以螺作动物蛋白饲料的水貂、鸡、鸭、对虾、螃蟹等食物链开发利用研究。各食物链饲养试验结果显示,增重效果和经济效益均很显著,螺的蛋白质转换效率高于国产鱼粉,但稍低于秘鲁鱼粉。