洞庭水患与生态环境保护

本文分析了洞庭湖流域生态环境破坏对洪涝造成的影响,指出流域生态环境受到破坏主要是人类违背自然规律、破坏森林植被、盲目围湖造田、生产及建设性破坏河道及湖滩所致。文章还就根治洞庭水患的关键性措施——搞好生态恢复,提出了几点意见。     

元代自然资源的保护和利用探幽

元代1264年定都燕京后,为加强政治统治,在中原先进的农耕经济影响下,改变过去“逐水草而居”游牧经济的生产方式,在积极保护动、植物资源和合理开发利用土地、水资源等方面,采取了一些恢复和发展农业生产的举措。剖璞见玉,对今仍有史鉴作用。     

对我国水资源可持续利用的一点思考

按照“认识——规划——建设”的思路,分析了我国水资源开发利用中所面临的主要问题和挑战,提出水资源可持续开发利用的策略和对策,特别提出分质供水和中水回用相结合的供水方式,作出了各地区重点建设项目的构想。     

Spectral analysis of forest model time series

The use of spectral analysis to elucidate the cyclic behavior in time series generated by a forest stand growth simulation model is discussed. A stand-level simulator, FORET, for an Appalachian deciduous forest is described. An estimate of the power spectral density of the total biomass time series is calculated. The power spectral density estimate indicates a dominant cyclic behavior with a period of about 200 years. In addition the spectral density is approximately bandlimited. This characteristic makes possible the application of the sampling theorem for analysis of sampling rates.     

活性污泥1#数学模型(ASM1)中的组分

活性污泥l#数学模型(AMl)常常用于预测污水处理厂中的生物过程。活性污泥数学模型组分的鉴定对活性污泥l#数学模型的应用具有重要的意义。本文描述了在活性污泥l#模型(ASMl)中污水组分的概念,以及组分鉴定的研究现状。     

Female brown-headed cowbirds' (<Emphasis Type="Italic">Molothrus ater</Emphasis>) social assortment changes in response to male song: a potential source of public information

In many species, females' behavior appears to be influenced by that of other females, particularly regarding mate choice. Females theoretically can reduce the costs associated with independent male assessment by observing conspecifics. Studies of brown-headed cowbirds suggest that females pay attention to other females' behavior. Group-housed females modify their song preferences, whereas females housed in pairs do not. What information is available to females in a group environment? To address this question, we studied two groups of juvenile (i.e. hatch-year birds) and adult female cowbirds in a naturalistic group setting. We used a longitudinal ABA design, consecutively introducing and removing males that differed in age, amount of song production and stage of song development, to isolate the male characteristics that related to changes in female behavior. Juvenile and adult females assorted by age class when singing adult males were in the aviary, but not when singing juveniles or silent males of any age class were in the aviary. Results from playback tests confirmed that adult male song alone influenced female age class assortment. Videotape analysis from playback tests revealed that females also wing stroked in response to male song. Other females sometimes approached females who wing stroked and observed them. We hypothesize that group-level changes in social organization and individual females' responses can serve as visual signals for other individuals.     

西部大开发要加强生态环境保护和建设

在实施西部大开发进程中,对原本生态环境十分脆弱的现状必须予以重视,切实加强生态环境保护与建设。     

浅论灾害科学的研究现状

在查阅了大量灾害科学方面的专著、期刊、学位论文和其它文献资料的基础上 ,本文试图对国内外的灾害科学研究现状进行粗浅的讨论     

基于数量化理论Ⅱ的鄂西北山区坡面土壤侵蚀强度评价

水土流失既是资源问题，又是生态环境问题。土壤侵蚀对人类生存和发展构成了严重威胁，成为制约可持续发展的障碍因素。以鄂西北丹江口库区郧西县坡面径流小区为试验点，通过分析小区的实地观测数据，建立坡面土壤侵蚀定性评价指标体系，并将数量化理论II作为有效的数学方法，建立郧西县坡面径流小区土壤侵蚀强度评价模型，对参与建立模型的样本进行回归分析，其准判率达到800%以上，并且利用该模型对其他年份坡面土壤侵蚀强度实测数据进行对比验证，得到土壤侵蚀强度分级的精度较高。研究表明，建立的郧西县坡面径流小区土壤侵蚀强度评价模型有较好的适用性与可靠性，可为郧西县及类似自然地理环境的其他区域水保工作起到一定指导意义