全文获取类型
收费全文 | 419篇 |
免费 | 46篇 |
国内免费 | 67篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 21篇 |
环保管理 | 95篇 |
综合类 | 228篇 |
基础理论 | 39篇 |
污染及防治 | 34篇 |
评价与监测 | 13篇 |
社会与环境 | 53篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 14篇 |
2020年 | 17篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 24篇 |
2016年 | 30篇 |
2015年 | 16篇 |
2014年 | 20篇 |
2013年 | 42篇 |
2012年 | 29篇 |
2011年 | 33篇 |
2010年 | 24篇 |
2009年 | 27篇 |
2008年 | 15篇 |
2007年 | 30篇 |
2006年 | 31篇 |
2005年 | 15篇 |
2004年 | 25篇 |
2003年 | 14篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 22篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 8篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有532条查询结果,搜索用时 296 毫秒
361.
362.
含油污水中固体废物固化与燃煤混烧的可行性 总被引:3,自引:0,他引:3
在含油污水处理过程中易产生含油污泥、活性污泥及浮渣等固体废物,利用传统的焚烧法、分离法、填埋法、生物降解法处理这些废物具有一定的缺陷和局限性。为了利用这些废物中的油及有机质的潜在能量,大庆炼化公司对固体废物进行了脱水固化试验。结果表明,脱水后的废物可以达到较好的固化状态,并具有一定的热值。固化废物经粉碎处理后,可按一定比例与燃煤混烧。在正常生产状况下,热电厂可保证混合燃烧的效果,其总体热值不会降低。混烧后的灰渣和炉渣可作为水泥厂的原料。该方法有利于环境保护,但其工业化生产可行性有待于进一步证实。 相似文献
363.
安全产品的供求特性及其与行业安全形势的关系初探 总被引:1,自引:0,他引:1
基于安全经济学的基本原理,通过对不同行业的自动安全水平和法定安全水平之间的关系的分析,论述了不同行业安全产品的需求特性,以及与此相适应的安全产品供给特性;并对安全产品的特殊供求机制与特定行业的安全形势之间的关系进行了初步的探讨,提出了提高行业安全水平的对策。 相似文献
364.
产品导向的环境政策研究进展 总被引:1,自引:0,他引:1
产品在整个生命周期都可能对环境造成不同程度的不利影响,因此传统的"末端处理"或"中端处理"的环境产品政策已经不能满足环境需要,产品导向的环境产品政策正是基于这种考虑产生的。通过介绍欧盟几个国家的产品导向的环境产品政策,论述了产品导向的环境产品政策的基本理论及研究进展。 相似文献
365.
南充地区秋季气候资源丰富,近几年由于推广良种良法,再生稻由零星试种到区域性种植获得成功,预示着新耕作制度的出现,这是开发秋季气候资源的一项重大突破。本文以大量数据阐述发展再生稻的生产潜力,分析了再生稻的生态气候适应性,指出伏旱高温和秋季低温冷害是发展再生稻的两个不利气象条件,并将全区划分为适宜、比较适宜和不适宜3个区,提出了相应的技术措施,为趋利避害发展再生稻提供了气象科学依据。 相似文献
366.
John J. Metz 《Environmental management》1994,18(3):371-390
This paper describes forest product use at Chimkhola, an upper elevation village of west central Nepal. Villagers have large
herds of livestock that they use to fertilize agricultural fields by holding the animals on cropland for one to several weeks
prior to planting. Herds are moved sequentially from one group of fields to another until all are planted, and then families
take animals into the forests. Herders, therefore, live in temporary shelters away from the homestead throughout the year,
and for much of the year feed their livestock fodder cut from forest trees. By combining repeated interviews of sample households,
one-time interviews with a large sample of village families, and direct measurements of forest products being used, I found
that livestock maintenance consumes 74% of the hand-harvested wild biomass: 26.4% for green fodder, 32.3% for fuelwood at
the herder's hut, and 13.8% for construction of the herder's hut. Fuelwood burned at the homestead is the next largest consumer,
17.6%. Villagers also use small amounts of forest materials for house construction, charcoal, agricultural implements, and
bamboo for baskets and mats. The large amounts used by herders and livestock at Chimkhola mean that wild vegetation use there
far exceeds the measurements made by previous reliable studies at other communities. This system of forest use is, however,
degrading Chimkhola's forests and gradually converting them to shrublands. 相似文献
367.
G. R. Soltani 《Journal of the American Water Resources Association》1977,13(1):137-142
ABSTRACT: The possibility of increasing the water supply for irrigation through adoption of more efficient water-application techniques as an alternative to new irrigation projects was studied in an irrigated region of Iran. Excessive water application at the farm level ranks high among the causes of water shortages in the selected region. An empirical analysis of the effect of water-saving technology on the farm operator's net return was made choosing two farms in the region as a case study. The problems facing these farms are common to most farms throughout the country. The results of the budgeting analysis of the selected farms indicated that an improvement in irrigation technique can result in the expansion of water supply and higher marginal value product for water. Comparing the costs of irrigation systems with the net returns resulting from the higher efficiency showed that such an investment is economically feasible. 相似文献
368.
Carl Blair Housley 《Journal of the American Water Resources Association》1972,8(4):679-684
ABSTRACT. Federal guidelines for the establishment of water quality standards prohibit degradation of the properties of all or part of the nation's aquatic resources. It is probably correct that streams, lakes and aquifers should be free of toxic substances while non-poisonous deposits should be abated. However, an extreme opposing position is held by some proponents of pollution who intend to continue discharging waste materials until forced to stop. Although it would seem otherwise, the underlying problem is that polluters' points of altercation possess merit in particular instances. Accordingly, efficient abatement will require that appropriate laws be formulated in such a manner that the nature of economic reasons for the disposal of waste materials be disclosed. Moreover, the technological ability to create byproducts from these particular elements or compounds can advance only over time. This, coupled with the fact that scientists have not developed inexpensive treatment methods which are totally effective, justifies more flexible formal regulations. Excessive rigidity of standards could impose a burden on polluters that is greater than the cost to society which the damaging firm or individual is generating. On the other hand, uniform rules in some cases could be considered so lenient as to allow flagrant contamination which unduly injures downstream users. 相似文献
369.
输油管道对环境的影响及其环境保护措施 总被引:1,自引:0,他引:1
使用管道长距离输送原油和成品油(管输)是石油工业一种现代文明的生产手段,它具有密闭、效率高、成本低和安全可靠等优点,在油品输送方面占据着主导地位。我国应用长距离输油管线始于50年代末期,在七、八十年代有了较快的发展。在管道建设的施工期会对地表造成破坏,管输油品的首站、中间泵站、末站及沿途管线由于腐蚀、事故等产生漏失油品而造成环境污染。本文介绍了几种漏失检测方法。 相似文献
370.
本文通过对南昌市名特优农产品资源、生产现状和市场条件的综合分析,确立了发挥地区资源优势,重点发展的名特优农产品,并进行了科学合理的规划和布局。 相似文献