超细粉尘的扬尘机理研究

针对目前对于一般尘源控制研究较少,而系统研究粉尘的扬尘(尘化)机理的研究就更少这一状况,提出弄清尘化机理、从源头上控制是治理粉尘的首要问题,对粉尘颗粒作用力进行分析,特别就超细粉尘的扬尘机理提出相应的物理模型并进行初步研究.图1,参2.     

膳食方式与学生体质状况的相关性研究

目的:了解不同就餐方式学生的体质状况,为提高膳食服务质量、增进学生体质健康发展提供参考依据.方法:对湖南环境生物职业技术学院南校区(简称湘环职院,下同)3个医科系和广西壮族自治区南宁市卫生学校(简称南宁卫校,下同)护理、口腔、中西医3个专业学生采用整群分层随机方法抽取794人进行就餐方式问卷调查和体格检查.结果:①在学校大食堂吃大众餐学生的身高、体质量、营养评价和发育状况均好于在学校小食堂现炒现吃学生、在自己家吃饭或亲戚朋友家搭餐学生和校外排档就餐学生;②4种就餐方式学生的体型评价和视力评价差异无显著.结论:在学校大食堂就餐学生的体质状况相对较好,应鼓励学生过集体生活,到学生大食堂吃大众餐.     

城市生活垃圾的工程特性

通过对江苏省泰州市生活垃圾的物理成分、物理特性的调查分析,得出泰州市生活垃圾不适于焚烧和堆肥处理,可以采用填埋方法的处理结论,为今后我国城市生活垃圾卫生填埋场的设计提供理论依据,并为废弃物减量化、无害化与资源化提供选择措施。     

地球物理环境与人类健康

阐述了地球物理环境的概念，以及原生物环境和次生物环境与人类健康之间的相互关系。文章指出，地球物理环境的存在及发展变化与人类的健康生存有密切的关系：由于现代生产活动所导致的的地球物理环境污染，破坏，已构成对人类健康的严重影响。文章呼吁，要加强对地球物理环境的保护，重视并开展这方面的有关研究，制订地球物理环境质量标准，切实保护好地球物理环境。     

长山群岛海区现代沉积特征

以１９８９￣１９９２年辽宁省海岛资源综合调查中海洋地质，海洋沉积资料为基础，通过对表层沉积物类型，粘土矿折的６个柱样＾２１０Ｐｂ沉积速率的分析，研究了长山群岛海区现代沉积特征。结果表明，该区沉积物类型分布与一般浅水海域近岸粗远岸细的泥沙分布规律截然不同，呈现出近岸细远岸粗、从西北向东南变粗的总趋势；４种主要粘土矿物的含量伊利石〉高岭石〉绿泥石〉蒙脱石，矿物组成明显受控于大陆沿岸河流输砂；沿岸河口区     

Coercive versus cooperative pollution control: Comparative study of state programs to reduce erosion and sedimentation pollution in urban areas

This article examines coercive and cooperative approaches to implementing state urban erosion and sedimentation pollution control programs. State administrators report serious shortfalls in their ability to control sources of pollution, but comparison of more and less successful programs provides evidence of what states can do to make programs more effective. Key ingredients for a successful state effort include the use of coercion with both the private sector and local government, adequate staffing, application of severe sanctions when violations of state standards are detected, and provision of technical assistance. Many state programs lack one or more of those elements, which explains their inability to adequately control urban erosion and sedimentation pollution.     

RIVER-BED SEDIMENTATION CAUSED BY OFF-ROAD VEHICLES AT RIVER FORDS IN THE VICTORIAN HIGHLANDS,AUSTRALIA1

ABSTRACT: This study investigates some of the effects occurring at recreational off-road vehicle (ORV) crossings on two rivers in eastern Victoria, where many road crossings occur at low-level fords. Further, it provides a method whereby the amount of sediment redeposited downstream of a ford can be measured. Attention is drawn to the fact that sediment is contributed to the river by five major processes: the creation of wheel ruts and concentration of surface runoff, the existence of tracks and exposed surfaces, the compaction and subsequent reduction in the infiltration rate of soils leading to increased surface runoff, backwash from the vehicle, and undercutting of banks by bow wave action. The last two of these processes have not been reported previously. Sediment collection experiments in two Victorian upland rivers indicate a mean deposition rate at the stream bed of approximately 1000 g m^?2 over a period of 30 days.     

LONG-TERM AQUATIC HABITAT RESTORATION: MAHOGANY CREEK,NEVADA, AS A CASE STUDY1

ABSTRACT: We compared the recovery from abusive grazing of aquatic habitat due to different range management on two geomorphically similar rangeland streams in northwest Nevada. Managers excluded livestock from the Mahogany Creek watershed from 1976 to 1990 while allowing rotation of rest grazing on its tributary Summer Camp Creek. Bank stability, defined as the lack of apparent bank erosion or deposition, improved through the study period on both streams, but periodic grazing and flooding decreased stability more on Summer Camp Creek than flooding alone on Mahogany Creek. Pool quantity and quality on each stream decreased because of coarse woody debris removal and sediment deposition during a drought. Fine stream bottom sediments decreased five years after the removal of livestock, but sedimentation increased during low flows in both streams below road crossings. Tree cover increased 35 percent at both streams. Thus, recovery of stability and cover and decreased sedimentation are compatible with rotation of rest grazing on Summer Camp Creek. Width/depth ratio and gravel/cobble percent did not change because they are inherently stable in this stream type. Management activities such as coarse woody debris removal limited pool recover and road crossings increased sedimentation.