晋陕蒙接壤地区的水土流失灾害及其防治

本文对晋陕蒙接壤地区的水土流失情况进行了简要论述,对水土流失的根源进行了探讨,并在此基础上提出了防治水土流失的基本措施。     

淮北市水资源保护与规划

系统论述了淮北市水资源现状和存在问题,提出了保护水资源环境、促进可持续发展而采取的有效工程措施。     

塔式起重机倾翻事故分析

塔式起重机事故是工业建筑事故中最严重的事故之一,给人们的生命和财产带来了巨大的损失。基于系统安全的原理,对塔式起重机事故进行了分类,并应用事故树分析方法分析了塔式起重机倾翻事故的原因,最后提出了预防塔式起重机倾翻事故的措施。     

分馏塔腐蚀原因分析及预防措施

针对目前炼厂原油性质越来越差,同时装置的生产周期越来越长的状况,结合生产实际对分馏塔顶部腐蚀漏液现象及原因进行了详细对比分析。提出选用合适的耐腐蚀材料、注缓蚀剂等措施,提高了设备的抗腐蚀能力,缓解了分馏塔顶部的腐蚀现象。     

气柜施工危险分析及安全对策

茂名炼油厂在新陈2#气柜的施工建设中,对施工危险性进行详细分析,提出了安全对策,采用3#气柜不停产的情况下进行,确保了施工安全.     

新疆油田钻井井喷风险分级及井控管理

为了减少新疆油田钻井溢流井喷事件,杜绝井喷失控事故,在统计新疆油田影响钻井井喷风险的地质环境因素的基础上,利用模糊数学理论建立了油田基于地质环境因素的钻井井喷风险分级模型,对各个区块的钻井井喷风险程度进行了分级,结果表明南缘山前构造勘探开发区块及克拉美丽气田的钻井井控风险值最高。建议对新疆油田钻井井控进行分级管理,针对不同的钻井井喷风险等级,制定了针对性的井控对策,建议在井控设计时考虑钻井井喷风险分级设计。     

未按规定导向车道行驶行为干预方法研究

为保障信号交叉口的正常交通秩序,充分遏制机动车未按规定导向车道行驶行为,亟需探究该行为的影响因素及干预方法。以北京市内4个信号交叉口处共35 h的1 666条监控视频数据为基础,对未按规定导向车道行驶行为进行定义并将其分为9类,分别对频率较高的5类未按规定导向车道行驶行为构建二元Logit模型,以确定其关键影响因素,并据此提出干预方法。结果表明,排队车辆数、大车比例、时段、车流量、照明条件等因素会不同程度地影响5类未按规定导向车道行驶行为的发生概率,其中排队车辆数及时间因素影响最为显著。在此基础上,从交通工程设施及驾驶人安全意识角度,提出优化交叉口渠化设计及信号配时、采用智能标线、强化监管力度及完善交通管控设施、加强驾驶人安全教育4种未按规定导向车道行驶行为干预方法。     

世界保护区事业发展的展望

当前,世界130个国家已建立了6500多个保护区,约占地球土地面积4.89％。但是,如何管理好它们,还存在许多问题。本文重点介绍这些问题,并提出一些解决措施,以促进保护区事业的发展。     

小城镇公众生态意识现状及策略——河北省东部小城镇生态意识调查

在对河北省东部进行的生态意识调查基础上，运用计量经济学方法分析了这些小城镇生态意识水平发展的一些规律，并提出了提高小城镇公众生态意识水平的一些对策。研究发现这些小城镇政府工作人员的整体生态意识处于浅层思考阶段，对指导环境保护仅具有启蒙性的意义，仍需提高到深层意识水平，才能更好地行使环境教育与环境决策的职责。研究还发现生态意识策略首先要加强对小城镇地区公众的生态安全教育，其次是注重转变经济增长方式，发展生态经济；关注中小学生的生态意识培养；同时尽力加强环境管理。     

Diatom Thalassiosira weissflogii in oligotrophic versus eutrophic culture: models and ultrastructure

Populations of marine diatom Thalassiosira weissflogii were grown in continuous cultures enriched with f/2 medium. One of the two contrasting cultures (‘eutrophic’) received 5.6 times more nutrients than the other (‘oligotrophic’). Two mathematical models are analyzed to estimate eutrophication differences. The second model based on the Michaelis–Menten uptake and Droop growth shows that cells in the eutrophic culture should have about 56% higher content of silica which is the limiting nutrient. Diatom samples were prepared for the transmission electron microscopy after cells have been kept in chemostats for 37 days. The structure of diatom cells was investigated and a comparison is made between cells grown in oligotrophic and eutrophic conditions. In eutrophic culture, dividing cells were encountered more frequently while cell concentration was approximately equal in both chemostats. The central vacuole of cells in eutrophic culture accumulated dispersed and compact material from amorphous to spherical shape. In some cells the large central vacuole had fibrilar and peppered dense materials in addition to translucent granules, vesicules and multivesicular bodies. In the cytoplasm we found increased number of multivesicular bodies, dense and lucent granules some of which enclose membrane particles and lucent vesicules. Dense material depositions observed in the vacuole are also seen in the cytoplasm associated with organelles, mitochondria and plasmalemma. Cells have well-developed, active and slightly increased number of dictyosomes (5–6). Some dictyosomes with dense secretory material in the cistern are apparently engaged in a granule formation process. Functional significance of dense material in the central vacuole, which has not been observed in cells grown in oligotrophic condition, is discussed.