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271.
本文研讨了泰山的31种野生蔬菜的分类地位、营养成分、食用方法和药用价值等,并对这些植物资源的开发利用提出了可行性措施 相似文献
272.
湖南省野生陆栖脊椎动物资源及其开发利用 总被引:1,自引:0,他引:1
通过调查,湖南省现有野生陆栖脊椎动物32目101科579种,约占全国陆栖脊椎动物总数的2786%。根据资源现状,本文提出了野生陆栖脊椎动物的开发利用途径、模式和对策 相似文献
273.
东北地区山野菜资源十分丰富,而山野菜具有很高的营养价值和保健价值,是绿色食品中的佼佼者。本文概述了我国东北山野菜的资源概况、营养成分、深层次加工及人工栽培方法 相似文献
274.
物理模型实验是研究边坡变形规律的重要手段之一.在高水胶比条件下(水:明胶:甘油=55:2:1)制备低强度软材料模型,利用铁氟龙镀层垫板和佳丹-108干性离型剂解决了脱模困难问题,同时利用材料熔化凝固的过程模拟了岩体的固结成岩过程,在小尺寸模型实验中,模拟了纯重力作用下节理边坡开挖的大变形过程.结果表明:随着坡面节理长度... 相似文献
275.
JULIA OHL-SCHACHERER‡ GLENN H. SHEPARD Jr . HILLARD KAPLAN† CARLOS A. PERES TAAL LEVI DOUGLAS W. YU 《Conservation biology》2007,21(5):1174-1185
Abstract: The presence of indigenous people in tropical parks has fueled a debate over whether people in parks are conservation allies or direct threats to biodiversity. A well-known example is the Matsigenka (or Machiguenga) population residing in Manu National Park in Peruvian Amazonia. Because the exploitation of wild meat (or bushmeat), especially large vertebrates, represents the most significant internal threat to biodiversity in Manu, we analyzed 1 year of participatory monitoring of game offtake in two Matsigenka native communities within Manu Park (102,397 consumer days and 2,089 prey items). We used the Robinson and Redford (1991) index to identify five prey species hunted at or above maximum sustainable yield within the ∼150-km2 core hunting zones of the two communities: woolly monkey (Lagothrix lagotricha), spider monkey (Ateles chamek), white-lipped peccary (Tayassu pecari), Razor-billed Currasow (Mitu tuberosa), and Spix's Guan (Penelope jacquacu). There was little or no evidence that any of these five species has become depleted, other than locally, despite a near doubling of the human population since 1988. Hunter–prey profiles have not changed since 1988, and there has been little change in per capita consumption rates or mean prey weights. The current offtake by the Matsigenka appears to be sustainable, apparently due to source–sink dynamics. Source–sink dynamics imply that even with continued human population growth within a settlement, offtake for each hunted species will eventually reach an asymptote. Thus, stabilizing the Matsigenka population around existing settlements should be a primary policy goal for Manu Park. 相似文献
276.
277.
现代城市建设中高层住宅建在深软土场地上是难以完全避免的。因深软土场地上的高层住宅易遭震害,地震安全性问题应予充分重视。建议将高层住宅建设工程列入需作“工程场地地震安全性评价”之列,高层住宅的防震减灾宜从城市建设规划着手,针对高层住宅易遭震害的动力学特性等采取相应对策。 相似文献
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279.
温州市区软土含水量高,压缩性大,90%以上的建筑物基础为桩基,由于市区旧城改造的加快,同一地块会多次施工建筑物,相应桩基的重复使用会造成"地基污染"灾害.该项人类诱发的地质灾害目前往往被人们所忽视,但从长期发展的角度考虑,却是一个重要的问题,围绕这个问题进行了思考、分析和探索,并提出了相应的防治对策. 相似文献
280.
In poorly buffered areas acidification may occur for two reasons: through atmospheric deposition of acidifying substances and – in mining districts – through pyrite weathering. These different sources of acidity lead to distinct clearly geochemistry in lakes and rivers. In general, the geochemistry is the major determinant for the planktonic composition of the acidified water bodies, whereas the nutrient status mainly determines the level of biomass. A number of acidic mining lakes in Eastern Germany have to be neutralized to meet the water quality goals of the European Union Directives and to overcome the ecological degradation. This neutralization process is limnologically a short-term maturation of lakes, which permits biological succession to overcome two different geochemical buffer systems. First, the iron buffer system characterizes an initial state, when colonization starts: there is low organismic diversity and productivity, clear net heterotrophy in most cases. Organic carbon that serves as fuel for the food web derives mainly from allochthonous sources. In the second, less acidic state aluminum is the buffer. This state is found exceptionally among the hard water mining lakes, often as a result of deposition of acidifying substances onto soft water systems. Colonization in aluminum-buffered lakes is more complex and controlled by the sensitivity of the organisms towards both, protons and inorganic reactive aluminum species. In soft-water systems, calcium may act as antidote against acid and aluminum; however, this function is lost in hard water post mining lakes of similar proton concentrations. Nutrient limitations may occur, but these do not usually control qualitative and quantitative plankton composition. In these lakes, total pelagic biomass is controlled by the bioavailability of nutrients, particularly phosphorus. 相似文献