全文获取类型
收费全文 | 765篇 |
免费 | 117篇 |
国内免费 | 440篇 |
专业分类
安全科学 | 97篇 |
废物处理 | 45篇 |
环保管理 | 63篇 |
综合类 | 763篇 |
基础理论 | 124篇 |
环境理论 | 1篇 |
污染及防治 | 143篇 |
评价与监测 | 19篇 |
社会与环境 | 36篇 |
灾害及防治 | 31篇 |
出版年
2024年 | 1篇 |
2023年 | 17篇 |
2022年 | 38篇 |
2021年 | 36篇 |
2020年 | 37篇 |
2019年 | 45篇 |
2018年 | 40篇 |
2017年 | 29篇 |
2016年 | 46篇 |
2015年 | 60篇 |
2014年 | 49篇 |
2013年 | 71篇 |
2012年 | 87篇 |
2011年 | 83篇 |
2010年 | 68篇 |
2009年 | 56篇 |
2008年 | 47篇 |
2007年 | 70篇 |
2006年 | 69篇 |
2005年 | 65篇 |
2004年 | 54篇 |
2003年 | 40篇 |
2002年 | 38篇 |
2001年 | 28篇 |
2000年 | 26篇 |
1999年 | 23篇 |
1998年 | 23篇 |
1997年 | 19篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1322条查询结果,搜索用时 328 毫秒
341.
三元缔合物抑制分光光度法测定痕量氟 总被引:6,自引:0,他引:6
利用氟离子对锆-水杨基荧光酮-溴化十六烷基三甲基铵三元缔合物形成的竞争抑制作用,建立了测定痕量氟的抑制分光光度法,确定了测定的最佳条件为:「SAF」=6.0×10^-5mol.L^-1「CTMAB」=8.0×10^-4mol.L^-1,「Zr(IV)」=1.0μg.ml^-1,「HCl」=0.08moL.L^-1,25℃。 相似文献
342.
343.
Alla I. Perfileva Antonina G. Pavlova Baira B. Bukhyanova 《Journal of environmental science and health. Part. B》2018,53(7):464-468
The effect of various pesticides on the biofilm formation by the phytopathogenic bacterium Clavibacter michiganensis ssp. sepedonicus (Cms), the potato ring rot causative agent, was explored for the first time. Systemic herbicides: 2,4-D, diuron, glyphosate, clopyralid, fluorodifen, as well as the commercial preparations “Lazurite,” “Ridomil Gold,” and the mitochondria inhibiting pesticides analog, sodium monoiodoacetate, were studied. These pesticides' effect on the Cms biofilm formation was shown to be distinct and dependent on the agent under question. Cms biofilm formation was reduced when exposed to sodium monoiodoacetate, as well as “Lazurite” preparation, that could be due to the bactericidal effect of these agents. 2,4-D and “Ridomil Gold” preparation stimulated the biofilm formation. Systemic herbicides diuron, glyphosate, clopyralid, fluorodifen did not exert appreciable influence on the process of bacterial biofilm formation. 相似文献
344.
345.
Biodegradation is an attractive approach for the elimination of synthetic polymers, pervasively accumulated in natural environments and generating ecological problems. The present work investigated the degradation of low‐density polyethylene (PE) by three Bacillus sp., that is, ISJ36, ISJ38, and ISJ40. The degree of biodegradation was assessed by measuring hydrophobicity, viability, and total protein content of bacterial biofilm attached to the PE surface. Although all three bacterial strains were able to establish an active biofilm community on the PE surface, ISJ40 showed better affinity toward PE degradation than the other two. Bacterial colonization and physical changes on the PE surface were visualized by scanning electron microscopy. Fourier transform infrared spectroscopy analysis revealed alteration in the intensities of functional groups along with an increase in the carbonyl bond indexes. The study results suggest that the Bacillus strain ISJ40 can be used as a potential degrader for the eco‐friendly treatment of PE waste. 相似文献
346.
347.
旅游综合体开发——一种旅游房地产全新开发模式研究 总被引:2,自引:0,他引:2
随着产业结构升级,旅游结构从原有的单一旅游经济模式向多元化的、集合式的、综合性的旅游模式发展,产生了以旅游资源与土地为基础,以旅游休闲功能为主导,结合大型旅游休闲项目、高品质服务的配套设施、互动发展的休闲旅游地产等多功能的、集合式的土地利用模式及产业聚集模式。在观察和归纳大量这类开发实例的基础上定义了旅游综合体开发这一房地产全新开发模式的概念,分析了该模式的表现特征,总结性地提出开发的理论模式及应用模式,并在此基础上归纳出开发的战略措施。 相似文献
348.
硝化型曝气生物滤池的挂膜与启动 总被引:5,自引:3,他引:2
近年来,曝气生物滤池广泛应用于污水硝化过程中,硝化型曝气生物滤池应运而生。采用快速排泥挂膜法和自然挂膜法相结合的复合挂膜法,考察了进水是否含有机物对硝化型曝气生物滤池挂膜的影响。在19℃、HRT=55 min、出水DO=8 mg/L、进水NH4+-N约为50 mg/L的条件下,两滤池挂膜启动时间差异较大,进水不含有机物的1#滤池挂膜成功仅需18 d,当其运行稳定时NH4+-N的去除率达到100%;而进水含有机物的2#滤池挂膜成功需24 d,当其运行稳定时,COD和NH4+-N去除率分别为84.6%和91.2%。此结果表明,与含有机物的实际生活污水相比,采用不含有机物的模拟生活污水启动硝化型曝气生物滤池挂膜启动时间可缩短6 d,这主要是由于异氧菌产率系数比硝化菌大。 相似文献
349.
场平爆破南北各有1个加油站,临近公路和高压线,对爆破振动和飞石控制严格,爆破设计和施工难度较大.介绍了该复杂环境下场平石方爆破设计和安全技术,可供类似工程参考. 相似文献
350.
Thodoris Dantsis Angeliki Loumou Christina Giourga 《Journal of Agricultural and Environmental Ethics》2009,22(3):197-216
Up to now, several scientific works have noted that the organic sector resembles more and more conventional farming’s structures,
what is widely known as the “conventionalization” thesis. This phenomenon constitutes an area of conflict between organic
farming’s original vision and its current reality and raises ethical and social questions concerning the structure of agricultural
systems of production and their interactions with the socio-economic and natural environment. The main issue of this dialogue
is the concept of sustainable agriculture, which for scientists and policymakers is a means to express their vision of a better
agriculture. In this article we focus on agricultural sustainability in the context of capitalist production as conducted
by the two subsystems of agro-industrial system. As we have proposed in this article, the relationship between organic agriculture,
defined by two essential components (prevention and direct marketing), and the agro-industrial complex, defined by two subsystems,
indicates the degree of agricultural sustainability. The investigation of this relationship can be extremely useful as it
may lead those involved in the discussion of sustainability to identify the key aspects of sustainable agriculture. In order
to investigate the interaction of organic farming with the agro-industrial complex, a survey was conducted in Central Macedonia,
Northern Greece, involving local organic farms. The results of our study indicate that a large proportion of organic producers
did not differ substantially from their counterparts in conventional agriculture in so far as their relationship with the
agro-industrial complex is concerned. Finally, this research highlights two scenarios for the evolution of organic farming.
The first is the full absorption of organic farming to the existing economic system and the second one is the development
of organic farming in a radically opposite direction to conventional farming. 相似文献