Preliminary studies on nitrous oxide emissions from the ornithogenic soils on Xi-sha atoll, South China Sea

IntroductionNitrousoxide (N2 O)isoneofthemostimportantgreenhousegases ,anditplaysanimportantroleinthedepletionofstratosphericozone (Crutzen ,1977;Zhu ,2 0 0 4 ) .TheatmosphericN2 Oconcentrationshavebeenincreasingattherateof 0 2 %— 0 3%peryearandthegl…     

Degradation of nitrobenzene in aqueous solution by ozone-ceramic honeycomb

IntroductionAs a promising advanced oxidation technology for watertreatment ,catalytic ozonation has received great attentionforthe efficient degradation of organic compoundsinrecent years(Legube , 1999) . Some studies showed that homogeneousand heterogen…     

Application of Bayesian regularized BP neural network model for analysis of aquatic ecological data-A case study of chlorophyll-a prediction in Nanzui water area of Dongting Lake

Bayesian regularized BP neural network（BRBPNN） technique was applied in the chlorophyll-α prediction of Nanzui water area in Dongting Lake. Through BP network interpolation method, the input and output samples of the network were obtained. After the selection of input variables using stepwise/multiple linear regression method in SPSS i1.0 software, the BRBPNN model was established between chlorophyll-α and environmental parameters, biological parameters. The achieved optimal network structure was 3-11-1 with the correlation coefficients and the mean square errors for the training set and the test set as 0.999 and 0.000？8426, 0.981 and 0.0216 respectively. The sum of square weights between each input neuron and the hidden layer of optimal BRBPNN models of different structures indicated that the effect of individual input parameter on chlorophyll- α declined in the order of alga amount 〉 secchi disc depth（SD） 〉 electrical conductivity （EC）. Additionally, it also demonstrated that the contributions of these three factors were the maximal for the change of chlorophyll-α concentration, total phosphorus（TP） and total nitrogen（TN） were the minimal. All the results showed that BRBPNN model was capable of automated regularization parameter selection and thus it may ensure the excellent generation ability and robustness. Thus, this study laid the foundation for the application of BRBPNN model in the analysis of aquatic ecological data（chlorophyll-α prediction） and the explanation about the effective eutrophication treatment measures for Nanzui water area in Dongting Lake.     

用于燃料电池的甲醇水蒸气重整反应制氢的研究

研究了甲醇水蒸气重整制氢反应过程中各种因素对Cu／ZnO／Al2O3催化剂的活性和选择性的影响。结果表明：Cu／Zn比为2．0的催化剂在250℃反应时，催化剂效果较好，最合适反应条件是：压力0．1MPa，温度250℃，n(H2O)：n(CH3OH)=1．0-1．2，液体流速0．1mL／min。在Cu／ZnO／Al2O3)，催化剂上，甲醇水蒸气重整、甲醇分解和水气转换反应随反应条件的不同而发生相互抑制或促进作用。     

冷挤大型法兰面螺母的工艺研究

以大型法兰面螺母为例 ,论述了用无缝钢管冷挤大型法兰面螺母工艺的可行性     

石灰石矿山环评中清洁生产的应用

石灰石矿山在我国分布广泛,矿山开采造成的资源浪费、环境污染等破坏因素非常复杂且难以恢复.针对这一特点,本文介绍了在石灰石矿山环评中运用清洁生产理念的一些实践.     

浅谈油田开发项目事故风险环境影响和防治措施——以大庆太19区油田开发为例

通过对国内外油田开发的类比事故调查及资料分析,结合大庆太19区油田开采的实际情况,事故风险主要来自于钻井(井下作业)天然气集输管线以及站场等工艺环节,危险其安全的潜在危险因素主要有自然灾害、腐蚀环境、误操作、设备缺陷、施工及人为破坏等同题.在油田开发过程中所发生的事故,不论是人为因素引起的还是自然灾害,其最终结果都是导致原油、天然气或含油污水的泄漏及火灾爆炸事故,并产生不同程度的环境风险,因此采取风险防治措施显得尤为重要.     

芳香化合物的光催化-臭氧联用降解研究

研究了几种芳香化合物的光催化 臭氧联用降解。探讨了光催化 臭氧联用技术降解有机物作用机理,分析了芳香化合物结构与反应活性的关系。实验结果表明,光催化 臭氧联用对芳香化合物的降解都存在一定的协同效应,而且符合表观准一级反应动力学规律;203#膜光催化臭氧的作用机理是催化臭氧产生了更多的高活性氧化剂,芳香化合物结构对其光催化 臭氧联用降解活性有很大影响。     

制备块体纳米材料的新工艺——等径角挤压

综述了等径角挤压法制备块体纳米材料的发展及其工艺原理 ,并在此基础上论述了等径角挤压材料的微观结构及其应用 ,指出了等径角挤压法目前存在的问题。     

封闭式芦苇湿地处理钻井泥浆的可行性研究

研究了现场中试条件下芦苇湿地处理钻井泥浆的可行性及钻井泥浆对土壤和芦苇等湿地介质的影响。研究结果表明：在7个月运行期内，单位面积钻井泥浆施入量5kg/m^2,20kg/m^2和40kg/m^2的芦苇湿地对矿物油的迁移降解率分别为75％－85％，78％－90％和65％－90％；钻进泥浆中的矿物油对湿地土壤的污染基本局限于表层，对深层土壤的污染趋势并不明显，一般40cm以下矿物含量已低于对照区表层土的背景值；钻井泥浆能增加芦苇的生物量，对芦苇品质指标的影响很小。