开县库区水土流失浅析

分析了开县库区水土流失的现状、原因及其危害，并提出了防治对策。     

中德中小学环境教育比较

从环境教育的概念出发，较系统地阐述了中德在中小学环境教育方面的异同，进而从认识，观念、科技，管理等角度提出了我国在实施中小学环境教育时可借鉴的一些看法。     

免烧免蒸粉煤灰砖的研究

本文讨论了免烧免蒸粉煤灰砖的生产原理，制造技术。试验结果表明利用化学复合外加剂能够成功地生产出免烧免蒸粉煤从砖，且产品质量达到红砖１００号的标准。文中还分析了生产粉煤灰砖的经济效益和社会效益。     

Enhanced twin pregnancy detection within an open neural tube defect and down syndrome screening protocol using free-beta hCG and AFP

We have applied our multimarker approach of maternal serum alpha-fetoprotein (AFP) and free-beta human chorionic gonadotropin (hCG) for Down syndrome screening to multiple gestations to assess its efficacy for improved detection of twin and triplet pregnancies. This study matched 225 cases of twin pregnancy and 39 cases of triplet pregnancy each with ten singleton pregnancies based on gestational week, race, time to receive sample, time of year of sample, and geographical area. The ratios of the MOM for each group at the tenth, 50th, and 90th percentiles were compared by the Wilcoxon test. Risks for twins were calculated using Bayes' rule, the age-related incidence of twins, and the levels of AFP and free-beta hCG. The tenth, 50th, and 90th percentiles of free-beta hCG MOMs in twin and triplet cases were 0.85, 1.99, and 4.51, and 1.38, 2.78, and 4.07, respectively. For AFP, the MOMs at these percentiles were 1.26, 1.91, and 2.99, and 2.02, 2.68, and 5.30, respectively. The twin and triplet distributions for each marker were statistically significantly different from the singleton distributions (P<0.0001) and from each other (P=0.0012). At a twin risk cut-off of 1 in 50, 77.4 per cent of all twin gestations can be detected in a second-trimester AFP and free-beta hCG screening protocol with 5.1 per cent of singleton pregnancies falsely identified as at risk for twins. Our dual marker protocol for mid-trimester pregnancy screening combining AFP and free-beta hCG can identify over 77 per cent of twin pregnancies in women less than 35 years of age. This benefit may contribute to an improved outcome of pregnancy by early detection of multiple gestation.     

油田行业"三废"综合利用研究

介绍了国家“三废”综合利用方面的政策，结合油田行业资源综合利用现状，提出如何进一步开展油田行业“三废”综合利用工作，并更好地利用国家资源利用税收方面的优惠政策，开拓油田行业“三废”综合利用渠道，推动“三废”综合利用，争取得到最大限度的减免税额。     

Effects of bifenthrin on Daphnia magna during chronic toxicity test and the recovery test

IntroductionWiththedevelopmentandapplicationofnewpesticide ,insecticidehasgreatlyreducedtheharmofpesttocrops .Bifenthrinisaneffectivepyrethroidinsecticideandacaricideagainstawiderangeofinsectpests ,anditisverypoisonoustomammal,aquatic .Thisinsecticideiswi…     

网络计划在液化气球罐内外部检验过程中的应用

在以工期考虑为重点的V-3002B液化气球罐内外部检验过程中，引用现代管理中网络计划技术关键路线法，为加快芳烃厂压力容器检验提供了科学的依据。本文总结和介绍了网络计划技术在芳烃厂贮运车间V-300亚球罐内外部检验过程应用情况。     

敖汉旗生态示范区调查研究对固阳县生态建设的启迪

通过参观学习提高自身认识，拓思路，产生构想，为做好本职工作奠定了基础，增强了信心。     

我国水资源的可持续利用和保护

随着科技的进步和经济的发展，我国水环境污染状况越来越严重，可以利用的淡水资源日益短缺，已成为制约我国经济发展的一项重要因素，我国政府为了解决我国的水资源问题，提出了“开源与节流”的重大举措，这对缓解我国目前的水资源短缺状况将起到非常重要的作用。本文就这些方面进行了论述，希望能引起大家对水的忧患意识。     

窄小场地条件下柴油发电机噪声综合治理

介绍一例窄小场地条件下柴油发电机噪声综合治理工程。通过对机房实行整体封闭隔声与吸声、以消声道兼作通风道强制通风、以消声器加垃圾道消除排气噪声等综合措施 ,使柴油发电机噪声完全达到标准。