全文获取类型
收费全文 | 1642篇 |
免费 | 57篇 |
国内免费 | 634篇 |
专业分类
安全科学 | 130篇 |
废物处理 | 93篇 |
环保管理 | 131篇 |
综合类 | 917篇 |
基础理论 | 304篇 |
污染及防治 | 591篇 |
评价与监测 | 49篇 |
社会与环境 | 43篇 |
灾害及防治 | 75篇 |
出版年
2024年 | 1篇 |
2023年 | 25篇 |
2022年 | 70篇 |
2021年 | 68篇 |
2020年 | 41篇 |
2019年 | 34篇 |
2018年 | 52篇 |
2017年 | 79篇 |
2016年 | 74篇 |
2015年 | 64篇 |
2014年 | 129篇 |
2013年 | 160篇 |
2012年 | 153篇 |
2011年 | 120篇 |
2010年 | 112篇 |
2009年 | 118篇 |
2008年 | 127篇 |
2007年 | 104篇 |
2006年 | 96篇 |
2005年 | 81篇 |
2004年 | 35篇 |
2003年 | 64篇 |
2002年 | 58篇 |
2001年 | 47篇 |
2000年 | 50篇 |
1999年 | 59篇 |
1998年 | 54篇 |
1997年 | 44篇 |
1996年 | 44篇 |
1995年 | 43篇 |
1994年 | 29篇 |
1993年 | 26篇 |
1992年 | 24篇 |
1991年 | 14篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有2333条查询结果,搜索用时 203 毫秒
61.
62.
关于沥青烟尘治理的工业安全与卫生评价 总被引:1,自引:0,他引:1
炭阳极生产过程存在着严重的环境污染问题 ,在诸多污染物中沥青烟尘对人类生存的危害最大 ,是企业和政府强化治理的重点。笔者结合某铝厂的技术改造工程 ,对沥青烟尘的治理加以讨论 ,将先进的生产工艺和成熟可靠的净化技术作为治理污染源的有效措施 ,以保证污染物的排放量达到国家标准要求。在技改过程中 ,严格按照所涉及的安全生产规程和标准 ,把它们作为技术改造设计原则、安全防范措施、工业卫生评价的依据。 相似文献
63.
64.
65.
66.
67.
68.
Water use efficiency (WUE) is an important ecophysiological characteristic of plants, especially in semiarid and arid regions. At the scale of community or ecosystem, WUE is difficult to quantify because the amount of water used per unit dry mass production is a function of microclimatic variables and species composition. In this study, we analyzed corrected intrinsic water use efficiency (IWUE(s)) of grass and shrub species along the western segment of the Northeast China Transect (NECT) and the relationship between IWUE(s) and mean annual rainfall, habitat degradation status, vegetation type, and plant functional type (C3 versus C4) at 22 survey sites. Site intrinsic water use efficiency (IWUE(v)) and its relationship with the aforementioned site variables were analyzed based on species frequencies at each site. First, it was concluded that photosynthetic pathway played a very important role in determining species IWUE(s). Mean IWUE(s) for C4 species was approximately double that of C3 species. Second, mean annual rainfall, vegetation type, and site degradation status significantly affected IWUE(s) (p < 0.01). Mean IWUE(s) at degraded sites was twice as high as that at nondegraded sites. The mean IWUE(s) for meadows was significantly higher than those for other vegetation types (p < 0.05). Third, the frequency of occurrence of C4 plants explained 36% of the variance in IWUE(v) across the survey sites. The mean frequency of C4 occurrence at degraded sites was more than double that at nondegraded sites. Consequently, mean IWUE(v) at degraded sites was more than double that at nondegraded sites. Dominant C4 species in saline-alkaline areas tended to have higher intrinsic WUE than dominant C4 species in sandy shrub communities. 相似文献
69.
Zhi-Long Ye Xiaoqing Xie Lanhua Dai Ziwen Wang Wenhua Wu Fuyi Zhao Xiaoming Xie Shiqing Huang Meiling Liu Shaohua Chen 《Waste management (New York, N.Y.)》2014,34(11):2305-2311
Fresh leachate, generated in municipal solid waste incineration (MSWI) plants, contains various pollutants with extremely high strength organics, which usually requires expensive and complex treatment processes. This study investigated the feasibility of blending treatment of MSWI leachate with municipal wastewater. Fresh MSWI leachate was pretreated by coagulation–flocculation with FeCl3 2 g/L and CaO 25 g/L, plate-and-frame filter press, followed by ammonia stripping at pH above 12. After that, blending treatment was carried out in a full-scale municipal wastewater treatment plant (WWTP) for approximately 3 months. Different operational modes consisting of different pretreated leachate and methanol addition levels were tested, and their performances were evaluated. Results showed that throughout the experimental period, monitored parameters in the WWTP effluent, including COD (<60 mg/L), BOD5 (<20 mg/L), ammonium (<8 mg/L), phosphorus (<1.5 mg/L) and heavy metals, generally complied with the Chinese sewage discharged standard. Under the experimental conditions, a certain amount of methanol was needed to fulfill TN removal. An estimation of the operation cost revealed that the expenditure of blending treatment was much lower than the total costs of respective treatment of MSWI leachate and municipal wastewater. The outcomes indicated that blending treatment could not only improve the treatability of the MSWI leachate, but also reduce the treatment cost of the two different wastewaters. 相似文献
70.