首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   263篇
  免费   11篇
  国内免费   76篇
安全科学   17篇
废物处理   8篇
环保管理   28篇
综合类   159篇
基础理论   46篇
污染及防治   64篇
评价与监测   13篇
社会与环境   7篇
灾害及防治   8篇
  2023年   3篇
  2022年   7篇
  2021年   12篇
  2020年   6篇
  2019年   8篇
  2018年   6篇
  2017年   2篇
  2016年   9篇
  2015年   17篇
  2014年   25篇
  2013年   17篇
  2012年   18篇
  2011年   23篇
  2010年   10篇
  2009年   13篇
  2008年   16篇
  2007年   19篇
  2006年   14篇
  2005年   9篇
  2004年   9篇
  2003年   4篇
  2002年   6篇
  2001年   7篇
  2000年   16篇
  1999年   13篇
  1998年   7篇
  1997年   10篇
  1996年   3篇
  1995年   8篇
  1994年   14篇
  1993年   6篇
  1992年   2篇
  1990年   3篇
  1989年   1篇
  1988年   3篇
  1986年   1篇
  1984年   1篇
  1982年   2篇
排序方式: 共有350条查询结果,搜索用时 15 毫秒
221.
通过对处理剂环保性能评价及作用效果优选、高密度环保钻井液配方及其钻井液的流变性、失水性、抗温性、抑制性、抗污染等综合性能评价等一系列实验研究,形成了一套适合山前构造带的环保钻井液体系。该钻井液具有无毒、易降解、密度高(2.0g/cm3和2.3g/cm3)、高温高压失水低、流变性好、抗高温可达130~140℃,性能稳定,抑制性、润滑性能好,抗污染能力强,既能够满足复合盐层钻井工程需求,又具环保性能好的特点。  相似文献   
222.
Road-deposited sediment (RDS) is an important environmental medium for impacting the characteristics of pollutants in stormwater runoff; it is of critical importance to investigate the water quality of urban environments. The paper develops a rainfall simulator as an important research tool to ensure homogeneity and reduce the large number of variables that are usually inherent to urban water quality research. The rainfall simulator was used to experiment runoff samples from typical residential and traffic areas in the Zhenjiang. The data show that land use is one of the major factors contributing to the difference in the pollutants concentration in the RDS. The maximum mean EMC for TN, TDN, TP, and TDP at residential area was 5.52, 3.07, 1.65, and 0.36 mg/L, respectively. The intense traffic area displayed the highest metal concentrations. Concentrations of runoff pollutants varied greatly with land use and storm characteristics. The correlation of pollutant concentrations with runoff times was another predominant phenomenon. Peaks in pollutants concentration occurred at 1 and 10 min during the whole storm event. A concentration peak that correlates with a peak in runoff flowrate correlates with rainfall intensity. The pollutant loadings (kilograms per hectare) in the Zhenjiang were 11.39 and 55.28 for COD, 8.42 and 57.48 for SS, 0.11 and 0.88 for TN, 0.02 and 0.14 for TP, 0.02 and 0.09 for Zn, and 0.01 and 0.04 for Pb. The higher rainfall contribute to the higher pollutant loading at the residential and intense traffic areas, as a result of the pollutant loadings direct dependence on rainfall intensity. The results confirmed that the rainfall simulator is a reliable tool for urban water quality research and can be used to simulate pollutant wash-off. These findings provide invaluable information for the development of appropriate management strategies to decrease nonpoint source contamination loading to the water environment in urban areas.  相似文献   
223.
This paper has two main objectives: (1) to discuss the basics of component modeling and its conceptual implications in environmental modeling; and (2) based on this discussion, to present a component-based design to support the simulation of wildlife movements. Components are independently developed, ready-to-use software units that can be assembled together to construct a modeling system. The conceptual implications of component modeling for the representation of environmental phenomena are discussed. A comparison is made between these conceptual implications and those of the more familiar object-oriented approach. A component-based design for supporting the simulation of wildlife movements is presented in this paper in order to illustrate how component modeling can be used to support the spatial representation of ecological phenomena and processes.  相似文献   
224.
根据中国在处置石化企业及园区突发环境事件的现状,明确了消防部门在现场处置中的先锋、基础和保证的重要作用。经过分析石化行业所存在的火灾、爆炸和环境的风险,提出了在抢险救灾中的选择环保泡沫、采取控而不灭措施、妥善处理泄漏物和消防污水等要求。指出当前环保和消防部门应建立预案、信息、技术、出警等方面应急联动的机制,并在现场处置中强化防护与协同、调查与询情、监测与侦检、警戒与警示、救生与救护、控险与输转、关阀与堵漏、洗消与清理等具体联动措施。  相似文献   
225.
Soils contain diverse colloidal particles whose properties are pertinent to ecological and human health, whereas few investigations systematically analyze the surface properties of these particles. The objective of this study was to elucidate the surface properties of particles within targeted size ranges (i.e. > 10, 1–10, 0.5–1, 0.2–0.5 and < 0.2 μm) for a purple soil (Entisol) and a yellow soil (Ultisol) using the combined determination method. The mineralogy of corresponding particle-size fractions was determined by X-ray diffraction. We found that up to 80% of the specific surface area and 85% of the surface charge of the entire soil came from colloidal-sized particles (< 1 μm), and almost half of the specific surface area and surface charge came from the smallest particles (< 0.2 μm). Vermiculite, illite, montmorillonite and mica dominated in the colloidal-sized particles, of which the smallest particles had the highest proportion of vermiculite and montmorillonite. For a given size fraction, the purple soil had a larger specific surface area, stronger electrostatic field, and higher surface charge than the yellow soil due to differences in mineralogy. Likewise, the differences in surface properties among the various particle-size fractions can also be ascribed to mineralogy. Our results indicated that soil surface properties were essentially determined by the colloidal-sized particles, and the < 0.2 μm nanoparticles made the largest contribution to soil properties. The composition of clay minerals within the diverse particle-size fractions could fully explain the size distributions of surface properties.  相似文献   
226.
要搞好环境监测工作 ,必须解放和发展环境监测生产力 ,履行“政府行为” ,贯彻“稳住一片 ,放开一头”的政策。环境监测工作具有政府行为组成的三种必备要素和五个特点 ;“稳住一片 ,放开一头”是因为环境监测所具有的本质属性、社会属性和法律属性  相似文献   
227.
附壁式爬模法在烟囱施工的安装、提升操作、高空拆除过程中的安全技术措施。  相似文献   
228.
本文通过对防弹衣的改进研究,探讨了利用经编间隔织物对防弹装备舒适性提高的可行性。用经编间隔织物代替传统防弹衣里料(平纹机织布),并制成成衣。通过红外热成像仪分别测试以经编间隔织物为里料的防弹衣的热湿传导性、透气散热性来探讨经编间隔织物对防弹衣的舒适性能的影响。实验结果表明:在相同测试条件下,以经编间隔织物为里料的防弹衣的热湿传导性能良好,透气散热性优于传统防弹衣1℃左右。因此经编间隔织物对提高防弹衣的舒适性能具有推动作用。本课题的研究意义在于为警用防弹衣的舒适性能提供理论参考,为警察或军队的作战能力提高做出更大的贡献。  相似文献   
229.
边丽 《防灾博览》2004,(1):23-23
1999年10月12日零点零二分,地球上的第60亿位居民,一个3.6公斤重的男婴在波黑首都萨拉热窝的一个医院降生,在我们为他祝贺的同时,是否也应想一想60亿人吃什么?烧什么?喝什么?  相似文献   
230.
结合实例阐述冶金建筑施工企业在建立环境管理体系中环境因素辨识及评价的方法。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号