全文获取类型
收费全文 | 512篇 |
免费 | 9篇 |
国内免费 | 58篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 22篇 |
环保管理 | 51篇 |
综合类 | 123篇 |
基础理论 | 113篇 |
污染及防治 | 173篇 |
评价与监测 | 69篇 |
社会与环境 | 18篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 13篇 |
2020年 | 14篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 19篇 |
2016年 | 24篇 |
2015年 | 14篇 |
2014年 | 23篇 |
2013年 | 62篇 |
2012年 | 11篇 |
2011年 | 20篇 |
2010年 | 25篇 |
2009年 | 23篇 |
2008年 | 23篇 |
2007年 | 26篇 |
2006年 | 23篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 21篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1982年 | 5篇 |
1979年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1971年 | 4篇 |
1966年 | 4篇 |
1965年 | 5篇 |
1964年 | 4篇 |
1963年 | 5篇 |
1961年 | 6篇 |
1960年 | 2篇 |
1958年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有579条查询结果,搜索用时 0 毫秒
61.
Nadella Ranjit Kumar Panda Satyen Kumar Badireddy Madhusudana Rao Kurcheti Pani Prasad Raman Ram Prakash Mothadaka Mukteswar Prasad 《Environmental science and pollution research international》2022,29(25):37527-37542
Environmental Science and Pollution Research - Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food production avenues including aquaculture. One hundred... 相似文献
62.
Wang Shulian Jiao Yiying Rao Zhi 《Environmental science and pollution research international》2021,28(23):28865-28875
Environmental Science and Pollution Research - The development of cyanobacterial blooms can have adverse effects on water bodies and may produce cyanotoxins. Several physical and chemical methods... 相似文献
63.
64.
本研究利用红外光谱(FTIR)、扫描电镜(SEM)和X射线粉末衍射(XRD)观察了共沉淀法合成羟基磷灰石(HAP)的形貌及其晶型结构,并探讨了Ca/P摩尔比、反应时间及反应温度等因素对羟基磷灰石吸附水中氟离子性能的影响。结果表明,n(Ca/P)=1.5/1、反应时间1 h、反应温度40℃、陈化时间48 h、煅烧温度200℃、煅烧时间2 h时,HAP除氟效果最佳,吸附效率和吸附容量分别达到68.8%和6.88 mg/g。实验数据Langmuir 等温模式拟合效果优于Freundlich模式,热力学参数计算可知,HAP对氟离子的吸附是自发 (ΔG0吸热 (ΔH0>0),熵增 (ΔS0 >0)的过程。HAP对氟离子的吸附符合拟二级反应动力学过程。 相似文献
65.
Ronald A. Chadderton Robert G. Traver Jayaram N. Rao 《Journal of the American Water Resources Association》1992,28(6):1069-1076
ABSTRACT: This paper presents a study which used a standard, hydraulic computer model to generate detailed design information to support conflict analysis of a water resource use issue. As an extension of previous studies, the conflict analysis in this case included several scenarios for stability analysis - all of which reached the conclusion that compromising, shared access to the water resources available would result in the most benefits to society. This expected equilibrium outcome was found to maximize benefit-cost estimates. 相似文献
66.
The impact of SO(2) on superoxide dismutase (SOD) and the ascorbate-glutathione cycle was investigated in a tolerant (cv. Punjab-1) and a sensitive (cv. JS 7244) cultivar of soybean (Glycine max (L.) Merr.). In spite of SO(2) stimulated SOD activities in both the cultivars, only cv. JS 7244 has significantly enhanced Malondialdehyde (MDA) contents. This differential response was attributed to the ability of cv. Punjab-1 to enhance glutathione reductase (GR) activity and to maintain high GSH/GSSG and ASA/DHA ratios. Post-fumigation analysis indicated the ability of cv. Punjab-1 to maintain SO(2)-enhanced antioxidants, whilst they declined in cv. JS 7244 the moment fumigation was terminated. Exposure of SO(2)-acclimated plants (cv. Punjab-1) with their enhanced antioxidants to 250 microg m(-3) SO(2) for 6 h exhibited no enhanced cellular injury (MDA content) when compared to that of control plants with their normal antioxidant levels. These results indicate a relation between the ability of a plant to maintain reduced glutathione (GSH) and ascorbate (ASA) and SO(2) tolerance, and they also present evidence for the ability of plants, with elevated antioxidants, to tolerate SO(2)-induced oxygen-free radical toxicity. 相似文献
67.
Fly- and scrubber-ash (weight ratio of approximately 1:3) from municipal solid waste incinerators (MSWI) are a major land-fill disposal problem due to their leaching of heavy metals. We uniformly mixed both types of ash with optimal amounts of waste glass frit, which was then melted into a glassy slag. The glassy slag was then pulverized to a particle size smaller than 38 μm for use as a cement substitute (20–40% of total cement) and blended with sand and cement to produce slag-blended cement-mortar (SCM) specimens. The toxicity characteristics of the leaching procedure tests on the pulverized slag samples revealed that the amount of leached heavy metals was far below regulatory thresholds. The compressive strength of the 28-day cured SCM specimens was comparable to that of ordinary Portland cement mortars, while the compressive strength of specimens cured for 60 or 90 days were 3–11% greater. The observed enhanced strength is achieved by Pozzolanic reaction. Preliminary evaluation shows that the combination of MSWI fly- and scrubber-ash with waste glass yields a cost effective and environmentally friendly cement replacement in cement-mortars. 相似文献
68.
Hydrogeochemical characterization of fluoride rich groundwater of Wailpalli watershed, Nalgonda District, Andhra Pradesh, India 总被引:1,自引:0,他引:1
A. G. S. Reddy D. V. Reddy P. N. Rao K. Maruthy Prasad 《Environmental monitoring and assessment》2010,171(1-4):561-577
The groundwater of Nalgonda district is well known for its very high fluoride content for the past five decades. Many researchers have contributed their scientific knowledge to unravel causes for fluoride enrichment of groundwater. In the present paper, an attempt has been made to relate the high fluoride content in the groundwater to hydrogeochemical characterization of the water in a fracture hard rock terrain—the Wailpally watershed. Groundwater samples collected from all the major geomorphic units in pre- and post-monsoon seasons were analyzed for its major ion constituents such as Ca2?+?, Mg2?+?, Na?+?, K?+?, CO $_{3}^{-}$ , HCO $_{3}^{-}$ , Cl???, SO $_{4}^{-2}$ , NO $_{3}^{-}$ , and F???. The groundwaters in the watershed have the average fluoride content of 2.79 mg/l in pre-monsoon and 2.83 mg/l in post-monsoon. Fluoride concentration in groundwater does not show perceptible change neither with time nor in space. The ionic dominance pattern is in the order of Na?+? > Ca2?+??> Mg2?+??> K??? among cations and HCO $_{3}^{-}\:\,>$ Cl????> SO $_{4}^{-2} >$ NO $_{3}^{-} >$ F??? among anions in pre-monsoon. In post-monsoon, Mg replaces Ca2?+? and NO $_{3}^{-}$ takes the place of SO $_{4}^{-2}$ . The Modified Piper diagram reflect that the water belong to Ca?+?2–Mg?+?2–HCO $_{3}^{-}$ to Na?+?–HCO $_{3}^{-}$ facies. Negative chloralkali indices in both the seasons prove that ion exchange between Na?+? and K?+? in aquatic solution took place with Ca?+?2 and Mg?+?2 of host rock. The interpretation of plots for different major ions and molar ratios suggest that weathering of silicate rocks and water–rock interaction is responsible for major ion chemistry of groundwater in Wailpally watershed. Chemical characteristics and evolution of this fluoride-contaminated groundwater is akin to normal waters of other hard rock terrain; hence, it can be concluded that aquifer material play an important role in the contribution of fluoride in to the accompanying water. High fluoride content in groundwater can be attributed to the continuous water–rock interaction during the process of percolation with fluorite-bearing country rocks under arid, low precipitation, and high evapotranspiration conditions. 相似文献
69.
随着我国油田相继进入开发后期,传统的滤料及设备过滤精度已不能满足注水的要求。因此,研究并开发了具有一定抗油污能力的新型过滤材料,设计了新型的超精细过滤器系列产品。对滤料进行的室内实验结果表明,在开始过滤的近10h内,过滤后的水中含油量基本上满足注水的水质要求。在开始过滤的近20h内,滤层的水头损失随时间的变化较为平缓;随着过滤时间的延长,水头损失变化加剧。从现场实验可以看出,所设计的过滤器有良好的过滤性能和抗冲击能力。新型过滤材料的研究成功解决了油田含油污水精细过滤的问题,新型过滤器也是含油污水超精细过滤的理想产品。 相似文献
70.