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971.
This paper analyses the extent to which the new Reagan mineral policy will encourage increased US production, substitution, recycling and conservation, domestic stock-piling and diversification of foreign supplies. Major inadequacies of the mineral policy are the transfer of responsibility for research and development from the government to the unprepared private sector, the lack of emphasis on short-term research and development in mineral processing technology, and the lack of coordination between minerals policy and national security and foreign policy. However, overall the policy is a positive step towards reducing the current US minerals supply vulnerability. 相似文献
972.
The Cache River of southernmost Illinois is used as a case study for developing and demonstrating an approach to quantitatively
link (1) national agricultural policy and global agricultural markets, (2) landowner's decisions on land use, (3) spatial
patterns of land use at a watershed scale, and (4) hydrologic impacts, thus providing a basis to predict, under a certain
set of circumstances, the environmental consequences of economic and political decisions made at larger spatial scales. The
heart of the analysis is an estimation, using logistic regression, of the affect of crop prices and Conservation Reserve Program
(CRP) rental rates on farmland owner's decisions whether to reenroll in the CRP or return to crop production. This analysis
shows that reasonable ranges for crop prices (80%–150% of 1985–1995 values) and CRP rental rates (0–125% of 1985–1995 rates)
result in a range of 3%–92% of CRP lands being returned to crop production, with crop prices having a slightly greater effect
than CRP rental rates. Four crop price/CRP rental rate scenarios are used to display resulting land-use patterns, and their
effect on sediment loads, a critical environmental quality parameter in this case, using the agricultural non point source
(AGNPS) model. These scenarios demonstrate the importance of spatial pattern of land uses on hydrological and ecological processes
within watersheds. The approach developed can be adapted for use by local governments and watershed associations whose goals
are to improve watershed resources and environmental quality. 相似文献
973.
Proactive Management of Air Quality 总被引:1,自引:0,他引:1
Traditional air resource management systems have difficulty in addressing global issues, sustainable development, direct citizen
participation, and integration with broad economic interests. As reactive management systems, they tend to be compliance-driven,
static, and rigid. In contrast, proactive management systems are principle-driven, innovative, and flexible. Bridge scientists
play a key role in supporting the transformation of raw data into wise action. Decision-makers need to integrate social values
with knowledge about emissions, atmospheric processes, and potential environmental effects using the primary tools of measurements,
monitoring, and modeling. The Alberta Clean Air Strategic Alliance, a unique partnership of governments, industry, and public
interest groups formed in 1994, operates a comprehensive air management system that is capable of addressing air issues of
greater complexity and uncertainty. Its success is measured by the satisfaction of its diverse stakeholders and by the number
and scope of its initiatives. 相似文献
974.
The presence of Whitethroats and their potential invertebrate prey in farmland trees and shrubs was investigated. The management of this vegetation by farmers, and their motivation for that management, was explored using participatory techniques. Whitethroats were associated with Guiera senegalensis, the shrub species which supports most caterpillars and spiders. Farmers reported declines in trees and shrubs since the 1950s, loss of fallow areas, declines in soil fertility and crop yields, and increases in the use of fire for clearing fields. Trees are valued by people for their cultural and medicinal uses and some species used by Whitethroats and other birds have potential for restoring soil fertility, although this was not recognised by farmers. More sustainable use of savanna farmland could have both agronomic and wider conservation benefits, and the provision of information that accommodates farmers' cultural and economic incentives could benefit both farmers and wildlife. 相似文献
975.
Human Population Numbers as a Function of Food Supply 总被引:1,自引:1,他引:0
Human population growth has typically been seen as the primary causative factor of other ecologically destructive phenomena. Current human disease epidemics are explored as a function of population size. That human population growth is itself a phenomenon with clearly identifiable ecological/biological causes has been overlooked. Here, human population growth is discussed as being subject to the same dynamic processes as the population growth of other species. Contrary to the widely held belief that food production must be increased to feed the growing population, experimental and correlational data indicate that human population growth varies as a function of food availability. By increasing food production for humans, at the expense of other species, the biologically determined effect has been, and continues to be, an increase in the human population. Understanding the relationship between food increases and population increases is proposed as a necessary first step in addressing this global problem. Resistance to this perspective is briefly discussed in terms of cultural bias in science. 相似文献
976.
以赭曲霉死菌丝体为载体,吸附红平红球菌(Rhodococcus erythropo lisNG0402)和白腐菌(Phanerochaete chrysosporiumM E-446)的混合物,用聚乙烯醇作包埋剂进行共固定化。用制备好的共固定化细胞处理增塑剂废水,连续运行19d的结果表明,共固定化处理增塑剂废水的效果远好于单一菌的效果。在pH7.0、溶解氧质量浓度3.0m g/L、水力停留时间25h的条件下,废水中苯酚、COD和色度的去除率连续15d达到了90%以上,对苯酚的去除能力为2.16kg/(m3.d)。 相似文献
977.
在此提出了天车通过式捕集工艺方法。并在45t转炉的烟气治理上得到成功应用,为解决45t以下中小转炉的问题开辟了新的途径。 相似文献
978.
979.
武咸城际铁路在咸宁市上跨武广高速铁路,安全风险极大。论述了跨高速铁路桥梁基础承台防护桩的设计和施工,分析了防护桩设计的影响因素,确定了计算桩长。此外,从单桩承载力、桩基内力及基地应力三方面计算进行了安全性验证,确保了桥梁承台施工安全,对类似工程的基础安全防护有较好的借鉴作用。 相似文献
980.