全文获取类型
收费全文 | 2831篇 |
免费 | 196篇 |
国内免费 | 68篇 |
专业分类
安全科学 | 161篇 |
废物处理 | 20篇 |
环保管理 | 1150篇 |
综合类 | 749篇 |
基础理论 | 391篇 |
环境理论 | 2篇 |
污染及防治 | 97篇 |
评价与监测 | 291篇 |
社会与环境 | 137篇 |
灾害及防治 | 97篇 |
出版年
2023年 | 21篇 |
2022年 | 49篇 |
2021年 | 58篇 |
2020年 | 77篇 |
2019年 | 53篇 |
2018年 | 61篇 |
2017年 | 99篇 |
2016年 | 107篇 |
2015年 | 106篇 |
2014年 | 108篇 |
2013年 | 145篇 |
2012年 | 103篇 |
2011年 | 181篇 |
2010年 | 111篇 |
2009年 | 138篇 |
2008年 | 137篇 |
2007年 | 159篇 |
2006年 | 138篇 |
2005年 | 105篇 |
2004年 | 93篇 |
2003年 | 99篇 |
2002年 | 64篇 |
2001年 | 87篇 |
2000年 | 73篇 |
1999年 | 85篇 |
1998年 | 61篇 |
1997年 | 46篇 |
1996年 | 55篇 |
1995年 | 47篇 |
1994年 | 33篇 |
1993年 | 30篇 |
1992年 | 28篇 |
1991年 | 21篇 |
1990年 | 16篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 23篇 |
1986年 | 24篇 |
1985年 | 24篇 |
1984年 | 23篇 |
1983年 | 13篇 |
1982年 | 13篇 |
1980年 | 16篇 |
1979年 | 19篇 |
1978年 | 21篇 |
1977年 | 15篇 |
1975年 | 10篇 |
1973年 | 16篇 |
1972年 | 14篇 |
1971年 | 16篇 |
排序方式: 共有3095条查询结果,搜索用时 343 毫秒
51.
南秀杰 《辽宁城乡环境科技》2007,27(2):62-64
介绍生态平衡城市的基本条件及抚顺市在建设生态平衡型城市中的基本状况的基础上提出了相关的措施。根据归纳和调查目前抚顺市在经济发展的9项指标中只有2项,环境保护指标15项中只有8项满足生态平衡型城市方面的指标。这说明抚顺市在这方面还存在着很大差距,于是文中进一步提出了相关建议和措施。 相似文献
52.
The Kyoto Protocol is the first step towards achieving the objectives of the United Nations Framework Convention on Climate Change and aims among others to promote ‘the protection and enhancement of carbon sinks and reservoirs’. To encourage afforestation for carbon sequestration a project must be economically viable. This study uses a model to analyse the impact on project viability of a range of carbon monitoring options, international carbon credit value and discount rate, applied to a Pinus radiata afforestation project in New Zealand. Monitoring carbon in conjunction with conventional forest inventory shows the highest return. Long-term average carbon accounting has lower accounting costs, compared to annual and 5 yearly accounting, as monitoring is only required every 5–10 years until the long-term average is attained. In this study we conclude that monitoring soil carbon stocks is not economically feasible using any of the accounting methods, when carbon is valued at US$ 10/t. This conclusion may be relevant to forest carbon sequestration projects elsewhere in the world and suggests care is needed in selecting the appropriate carbon monitoring options to avoid the risk that costs could be higher than any monetary benefits from terrestrial carbon sequestration. This would remove any commercial incentive to afforest for carbon sequestration reasons and severely limit the use of forest sinks as part of any package of measures addressing the ultimate objective of the UNFCCC. 相似文献
53.
Zhou Zai zhi 《环境科学学报(英文版)》1999,11(2):174-180
1IntroductionHighlyproductivelanduseresultsinacontinuouschangeoflandscapesinruralareas.Undertheimpactofcropproductmarkets,lan... 相似文献
54.
55.
环境突发性事故采样的注意要点 总被引:2,自引:0,他引:2
根据环境突发性事故的特点,以作者工作经验,就事故采样的完整、典型,及时性以及样品保存4个方面,结合实例进行论述。 相似文献
56.
57.
A survey was carried out to determine the effect of prenatal screening and therapeutic abortion on births in 1985 with anencephaly and spina bifida in England and Wales. Maternal serum alpha-fetoprotein tests were done on 399 288 women (60 per cent of pregnant women): 4 per cent were reported as being screen-positive and 1 per cent had an amniocentesis. An estimated 534 pregnancies associated with anencephaly were terminated and an estimated 445 pregnancies associated with spina bifida (but without anencephaly) were terminated. Most (63 per cent) of the anencephalic pregnancies were first suspected from an ultrasound examination; 57 per cent of the spina bifida pregnancies were first suspected from a positive maternal serum alpha-fetoprotein test, 35 per cent by ultrasound, and the remaining 8 per cent by other means. The birth prevalence of anencephaly declined by 94 per cent between 1964–1972 and 1985, but when the terminations of pregnancy on account of having a fetus with anencephaly are added to the births the decline in prevalence was only 50 per cent. The birth prevalence of spina bifida declined by 68 per cent over the same period but when the terminations were added to the births the decline in prevalence was only 32 per cent. Among births with anencephaly 66 per cent had had no screening or diagnostic tests in early pregnancy, but in those that did nearly all were positive–usually in twin pregnancies where one fetus was affected but not the other. Among births with spina bifida, 48 per cent had no tests and in those that did the results were mainly negative. We conclude that in order to monitor adequately the national screening programme for anencephaly and spina bifida a special neural tube defects register should be formed. 相似文献
58.
以某取水河道的某一次监测结果为例子,以GB 3838-2002《地表水环境质量标准》为依据,探讨运用模糊数学对水源水进行分析的方法,绘制圆形比例图,显示各种污染物对水源水质"贡献",从而列出风险污染物清单,以便在工程中采用适当的处理工艺. 相似文献
59.
60.
介绍位于纽约州北汉姆斯特城的PortWashington城市固体废弃物填埋场填埋气体的排放、监测和处理系统及其有关测试数据和从中得到的启示. 相似文献