天津地铁1号线轨道减振措施应用及效果

介绍了地铁运行振动对环境的影响,概述了目前国内常用的轨道减振措施。结合天津地铁1号线实际工程情况分析了减振措施及效果。     

高烈度地震区隧道软硬围岩交接段刚柔并济抗减震技术研究

为提高高烈度地震区隧道抗震性能,以某铁路隧道为研究背景,分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数,通过对比分析得到最优抗减震措施.结果表明:相比于工况1,工况2隧道拱顶沉降减小10.54％ ～81.10％,边墙收敛减小13.92％ ～78.77％,衬砌结构PGA减小31.4...     

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.     

治理噪声污染 保障人身健康

阐述氧气生产过程中噪声的产生及对人体的危害性，实施多种噪声防治措施，取得显著成效。     

长输管道穿越河流的环境影响及对策浅析

由于近年来施工机械及河流穿越技术的不断进步,对于各地区不同的气候和地质条件,各类长输管道穿越河流等特殊地段的施工方式日趋多样化,除工程成本及管线安全性外,也更多的考虑到了工程施工给周边环境带来的不良影响,如何在穿越地段选择合理的施工方式和污染防治措施已成为工程设计阶段的重要关注点,本文主要针对目前中国油气长输管道穿越河流段普遍采用的施工方式进行环境影响分析,并在此基础上提出相应污染防治措施。     

试论我国农业环境保护战略问题

我国是发展中的国家，农业在国民经济中占有十分重要的地位，环境污染和生态破坏是农业潜伏着的生态危机，也是农业发展过程中亟待解决的重大问题。如何从我国农业环境问题的特点和农业经济现状出发，制定出与农业经济发展相适应遥农业环境保护战略，是我国农业发展和环境保护工作中的一项重要任务。本文就我国农业环境保护的战略地位和作用、指导思想和方针、目标和重点、措施等一系列战略问题，进行初步探讨。     

苯罐安全储存技术措施

液态苯极易燃烧爆炸,苯类化学事故造成的后果及影响极大,其安全储存涉及多方面技术措施.通过危险预知分析等方法,较详细地介绍了苯罐的安全储存温度和安全储存的技术措施.     

松花江流域面源污染特征与防治对策

在概述松花江流域水环境状况的基础上,分析了其面源污染的特征,农药流失、超量和不合理施用化肥、规模化养殖、生产、生活污水排放是流域面源污染的主要来源。结合面源污染特征等因素,有针对性地确定治理技术,如加强对面源污染防治工作重要性的认识、作好面源污染监测和防治技术示范推广工作、发展循环型农业等,提出了保护与治理可行的污染防治对策。     

Does intensity of change matter? Factors affecting adoption of agri-environmental schemes in Spain

Agri-environmental schemes (AES) are the main policy instrument currently available in the EU to promote environmentally-friendly farming practices. However, the rate of adoption of these measures is still relatively low in southern Europe, and understanding how these rates can be increased is still an open issue. The goal of this paper is to increase that understanding by testing whether the factors which determine AES sign-up decisions are influenced by the intensity of change in farming practices that are brought about by adopting the scheme. A micro-economic model reflecting farmer AES sign-up decisions is proposed and applied to two schemes in Spain respectively requiring major or minor intensity of change in practices by surveying farmers eligible for both schemes. The results show that farm structural factors play a role when major practice change is required by the scheme, yet when dealing with minor change, individual farmer characteristics play a more determining role. Social capital and farmer attitude are important factors in both the AES surveyed. Therefore, it may be concluded that improving agronomic design would be an important tool to improve farmer participation in AES where major change is involved, whereas improved targeting and extension would help uptake for AES involving a lesser degree of change.     

采用节水措施促进秦皇岛市水资源可持续发展

水资源是人类生存与发展最宝贵的自然资源,是任何其他资源都无法取代的、有限的资源.中国人均水资源量只有世界人均占有量的四分之一,是一个水资源贫乏的国家.秦皇岛市人均水资源量为597 吨/年,是全国平均值的1/4左右,属于缺水城市.在可供水不断减少的情况下,水资源需求量又在不断增加,因此,未来水资源的短缺形势将更为严峻,以水资源紧张为特征的水危机将会不断加剧.面对水资源短缺危机,节水成为秦皇岛市水资源可持续利用的根本出路.