全文获取类型
收费全文 | 31015篇 |
免费 | 2074篇 |
国内免费 | 6063篇 |
专业分类
安全科学 | 3431篇 |
废物处理 | 574篇 |
环保管理 | 6601篇 |
综合类 | 17285篇 |
基础理论 | 3002篇 |
环境理论 | 10篇 |
污染及防治 | 3204篇 |
评价与监测 | 2097篇 |
社会与环境 | 1829篇 |
灾害及防治 | 1119篇 |
出版年
2024年 | 133篇 |
2023年 | 581篇 |
2022年 | 891篇 |
2021年 | 1015篇 |
2020年 | 1134篇 |
2019年 | 876篇 |
2018年 | 770篇 |
2017年 | 1084篇 |
2016年 | 1342篇 |
2015年 | 1388篇 |
2014年 | 1435篇 |
2013年 | 1920篇 |
2012年 | 2126篇 |
2011年 | 2386篇 |
2010年 | 1662篇 |
2009年 | 1848篇 |
2008年 | 1392篇 |
2007年 | 2116篇 |
2006年 | 2037篇 |
2005年 | 1674篇 |
2004年 | 1496篇 |
2003年 | 1442篇 |
2002年 | 1226篇 |
2001年 | 1037篇 |
2000年 | 973篇 |
1999年 | 864篇 |
1998年 | 607篇 |
1997年 | 530篇 |
1996年 | 419篇 |
1995年 | 385篇 |
1994年 | 335篇 |
1993年 | 321篇 |
1992年 | 222篇 |
1991年 | 154篇 |
1990年 | 120篇 |
1989年 | 105篇 |
1988年 | 105篇 |
1987年 | 84篇 |
1986年 | 58篇 |
1985年 | 43篇 |
1984年 | 69篇 |
1983年 | 69篇 |
1982年 | 69篇 |
1981年 | 82篇 |
1980年 | 90篇 |
1979年 | 81篇 |
1978年 | 51篇 |
1977年 | 49篇 |
1973年 | 48篇 |
1971年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
221.
贵州木本食用油料资源及其开发利用 总被引:9,自引:0,他引:9
对贵州野生特有和稀有的大宗木本食用油料的种类、分布、现状等进行了分析,提出了提高大宗食用木本油料经营水平,选择利用野生木本油料植物资源,加强特有和稀有资源的保护、驯化和繁殖等开发利用建议。 相似文献
222.
连云港市地处欧亚大陆桥的东桥头堡,是沿海十四个开放城市之一,国家定位是将其建设成为连接太平洋沿岸与中亚地区的国际商贸中心和全国性的旅游城市。而目前的山丘区水土流失严重,植被稀少,生态环境恶化,与国家定位目标和连云港市发展目标相差甚远。因此在制定水土保持生态环境建设规划时,必须紧紧围绕改善生态环境这条主线,以增加农民收入和改善生存条件为突破口,因地制宜,坚持长期综合治理,方能实现“山川秀美”之目标。 相似文献
223.
本文以从严治党、加强党风廉政建设的角度出发,提出加强党内监督的三个途径,以便抓好党员干部廉洁自律,遏制腐败现象,建立一整套行之有效的党内监督机制,用制度来保证党内监督的有效开展。 相似文献
224.
矿井水是宝贵的地下水资源 总被引:1,自引:0,他引:1
本文针对煤矿矿井水是废水的错误认识,深入浅出地讨论了矿井水的水质特征,鲜明地提出矿井水是宝贵的地下水资源的观点,以及矿井水资源化的法规保证。 相似文献
225.
Bob Bermond 《Journal of Agricultural and Environmental Ethics》1997,10(3):227-247
The psychological literature about consciousness has been analyzed. It is argued that:
1) Only the higher symbolic cognitive powers like the ability to keep secrets, knowledge of self or self-consciousness, a
long-term view on the future, the ability to determine long-term goals, and to freely plan future behavior, add positive fitness-value
to consciousness. Without these higher intellectual abilities consciousness will have only negative fitness value and no positive
one. The intellectual powers mentioned may therefore be considered as prerequisites for consciousness. Consciousness may therefore
only be expected in those animal species that show these capacities in their behavior. So far these capacities have only been
described for the anthropoid apes and humans. For the time being, they are therefore the only species in which consciousness
may be expected.
2) Consciousness is not synchronous with real time. Human consciousness is, in as well in the perception of stimuli as in
the experience of free will to act, most times running after the facts.
3) Consciousness has to be viewed as an instinct that has been developed late in evolution. It is partially based upon primarily
innate neural circuits, fulfilling specialized cognitive functions by which information is interpreted and inferences are
made, in a more or less automatical way.
4) Most information processing concerning daily decisions,is done by parallel non-consciously functioning neural modules using
‘sloppy logic’, and only the end-product of these modules can be pushed forwards to consciousness. For this reason consciousness
will, most times, lack the necessary information to come to the correct inferences about the evaluations on which the decision
is based. Therefore, only rarely will people have insight into their cognitive processes or the real sources of their behavior.
When asked why they behaved as they did, they will produce confabulations. However, people's erroneous reports are not capricious,
but regular and systematic in such a way that they will fit the pre-existing ideas and beliefs. The contents of these reports
are therefore not based upon introspection, but, most times, on (sub)culturally accepted ideas.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
226.
227.
从综合治理,合理利用采出污水的长远利益出发,针对东部油田高含水阶段的新特点,提出地面高效处理,地下控水稳油相结合的治理策略,探讨了相关的技术和方法,并讨论了采出污水回注利用中应加强研究的几个问题。 相似文献
228.
西藏自治区土地资源的适宜性评价与利用 总被引:4,自引:0,他引:4
本文综合评价了西藏自治区土地资源的适宜性及其质量.阐明了影响土地资源潜力发挥的主要限制因素,分析了土地资源利用现状、存在问题和开发潜力。并在此基础上、提出了西藏自治区土地资源合理开发利用的方向、对策和措施。 相似文献
229.
John H. Martin 《Journal of the American Water Resources Association》1997,33(4):741-753
ABSTRACT: On May 19, 1993, a jury in the U.S. District Court for the Western District of New York found Southview Farm and Richard H. Popp guilty of violating the Clean Water Act on five occasions. The violations were the result of storm water runoff from a site used for disposal of dairy cattle manure from an unpermitted concentrated animal feeding operation. The presiding District Court judge later dismissed the jury verdict, and subsequently a U.S. Court of Appeals for the Second Circuit reversed the dismissal. The Court of Appeals concluded that the discharges were not exempt as agricultural storm water discharges, and that the manure spreaders involved were point sources. Because the use of animal manures in crop production activities will result, unavoidably, in the discharge of some pollutants to adjacent surface waters, a rational and universally applicable basis is needed to determine when such discharges are point versus nonpoint source. Current statutes and regulations do not delineate clearly such a boundary. To address this lack of specificity, I propose that application rates be based on recommended crop nutrient needs. 相似文献
230.