全文获取类型
收费全文 | 730篇 |
免费 | 125篇 |
国内免费 | 352篇 |
专业分类
安全科学 | 125篇 |
废物处理 | 68篇 |
环保管理 | 61篇 |
综合类 | 560篇 |
基础理论 | 158篇 |
污染及防治 | 177篇 |
评价与监测 | 29篇 |
社会与环境 | 10篇 |
灾害及防治 | 19篇 |
出版年
2024年 | 3篇 |
2023年 | 26篇 |
2022年 | 35篇 |
2021年 | 34篇 |
2020年 | 38篇 |
2019年 | 29篇 |
2018年 | 35篇 |
2017年 | 40篇 |
2016年 | 51篇 |
2015年 | 69篇 |
2014年 | 55篇 |
2013年 | 91篇 |
2012年 | 79篇 |
2011年 | 86篇 |
2010年 | 55篇 |
2009年 | 57篇 |
2008年 | 43篇 |
2007年 | 58篇 |
2006年 | 63篇 |
2005年 | 51篇 |
2004年 | 47篇 |
2003年 | 28篇 |
2002年 | 40篇 |
2001年 | 16篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
排序方式: 共有1207条查询结果,搜索用时 156 毫秒
991.
992.
Martin E. Spongberg Wesley P. James 《Journal of the American Water Resources Association》1996,32(3):485-490
ABSTRACT: Water quality in the Brazos River of Texas is seriously degraded by natural salt pollution. Two thousand tons/day of total dissolved solids emanate from brine springs and seeps in the Upper Brazos River drainage. Approximately 45 percent of the total salt load comes from a relatively small flow in the Dove Creek area. The companion paper demonstrates that a system of wells pumping brine at a constant rate of about 2 cfs from the near surface aquifer should eliminate the brine springs in this area. In this paper, injection into deep brine aquifers is shown to be a feasible brine disposal alternative. Four brine aquifers were determined from the literature to be possible injection zones. Accurate net aquifer thickness maps were generated in a 23 by 14 mile area centered on the Dove Creek area for three of the aquifers from an interpretation of 41 well logs. Constant injection for a project life of 100 years was simulated using the SWIFT/486 software. Modeling suggests that one well would be sufficient to inject the entire disposal volume into either the Strawn or Ellenburger Formation. 相似文献
993.
以双氰胺和甲醛为主原料,在添加改性剂的条件下制备了改性双氰胺-甲醛缩聚物,并直接与硫酸亚铁复合成脱色絮凝剂;以活性艳红X-3B染料废水的脱色率和CODCr去除率为考核指标,探讨了硫酸亚铁投加方式、复合质量比、pH等因素对活性艳红X-3B处理效果的影响。研究结果表明,在一定投加量下,复合脱色絮凝剂处理活性艳红X-3B染料废水的脱色率和COD去除率分别为99%和约75%左右。 相似文献
994.
995.
当前,城镇污水处理厂尾水对受纳水体的水质有着不可忽视的影响。以改善湖泊水质为目的,使用仿生组合工艺对尾水进行深度净化研究。结果表明:仿生组合工艺对尾水COD 的降解效率达到42.31%~67.95%,对COD波动具有较高的适应性;仿生组合工艺弥补了仿生填料床对NH3-N、TP的降解具有适应期的缺陷;仿生组合工艺对尾水NH3-N去除率高达89.57%~97.89%;仿生组合工艺强化了对TP的去除率,去除率为53.85%~72.41%,出水TP达到地表水III类水标准;仿生组合工艺SS去除效率达到37.50%~64%。 相似文献
996.
通过近三年实验室采用亚甲基蓝分光光度法测定硫化物校准曲线制作的一系列原始数据的收集,并通过数理统计方法对校准曲线、-余标准偏差、斜率扩展不确定度、截距扩展不确定度开展了详细讨论,得出亚甲基蓝分光光度法测定硫化物校准曲线斜率(b)参考范围为:0.019 1±0.00044,截距(a)参考值范围:0.003 3±0.005 0.此结果对实验室分析人员判定硫化物项目校准曲线制作是否合格具有一定的参考价值. 相似文献
997.
998.
在二级生物处理工艺确定后,深度处理工艺的选择是保证整个工程出水水质的关键。过滤是污水深度处理工艺中最重要的工序,用以去除原水经沉淀后的残留絮体和杂质,具体依据出水效果、处理效率、投资成本和占地等各方面,确定采用深床过滤工艺。从整体优化的角度出发,结合设计规模,进水水质特征和出水水质要求以及当地的实际条件和要求,选择切实可行且经济合理的深度处理工艺方案,是实现整个长沙市敢胜垸污水处理厂最佳工艺方案的保障。 相似文献
999.
In order to study how water level fluctuations (WLF) of reservoir influence the macroinvertebrate in tributary bay, we studied the effect of WLF of the Three Gorges Reservior on macroinvertebrate communities in Xiangxi Bay, and the time lags of such effect, based on the surveys in spring and summer from 2005 to 2010. In this research, WLF was represented by water level drawdown (WLD) and the sum of absolute values of rate of water level fluctuations (RWlf). Pearson correlation analysis was used to analyze the relationship between WLF and macroinvertebrates. No significant correlation was found between macroinvertebrates and sum of absolute values of RWLF, while WLD showed significant influence on some biotic parameters. In spring, WLD did not cause significant effect to macroinvertebrates (P > 0.05). In summer, however, the influence was significant, especially in the area of the downstream (XX01 - XX02) of the Xiangxi Bay (P < 0.05). The middle reach of the bay (XX05), located in the conjunction area between Xiangxi Bay and a secondary tributary of the TGR, was also affected significantly (P < 0.05). The relative abundance of Tubificidae declined with the increase of the WLF, while abundance of Chironomidae increased. The time lags of the influence to macroinvertebrates were about 15 days. This analysis indicated that WLF in the mainstream of the reservoir mainly influences the downstream of the tributary bay, and also affects the conjunction area of the secondary tributary. Chironomidae are more tolerant than Tubificidae in water-body with dramatic disturbance, therefore can be considered as the indicator of the effect of summer WLF on macroinvertebrates. 相似文献
1000.
A National Assessment of the Potential Linkage between Soil,and Surface and Groundwater Concentrations of Phosphorus 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R.W. McDowell N. Cox C.J. Daughney D. Wheeler M. Moreau 《Journal of the American Water Resources Association》2015,51(4):992-1002
A meta‐analysis of three national databases determined the potential linkage between soil and surface and groundwater enrichment with phosphorus (P). Soil P was enriched especially under dairying commensurate with an increase in cow numbers and the tonnage of P‐fertilizers sold. Median P concentrations were enriched in surface waters receiving runoff from industrial and dairy land uses, and in groundwater beneath dairying especially in those aquifers with gravel or sand lithology, irrespective of groundwater redox status. After geographically pairing surface and groundwater sites to maximize the chance of connectivity, a subset of sites dominated by aquifers with gravel and sand lithology showed increasing P concentrations with as little as 10 years data. These data raise the possibility that groundwater could contribute much P to surface water if: there is good connectivity between surface and groundwater, intensive land use occurs on soils prone to leaching, and leached‐P is not attenuated through aquifers. While strategies are available to mitigate P loss from intensive farming systems in the short‐term, factors such as enriched soils and slow groundwater may mean that despite their use, there will be a long‐term input (viz. legacy), that may sustain surface water P enrichment. To avoid poor surface water quality, management and planning may need to consider the connectivity and characteristics of P in soil‐groundwater‐surface water systems. 相似文献