全文获取类型
收费全文 | 5652篇 |
免费 | 440篇 |
国内免费 | 1265篇 |
专业分类
安全科学 | 434篇 |
废物处理 | 738篇 |
环保管理 | 982篇 |
综合类 | 3376篇 |
基础理论 | 530篇 |
环境理论 | 2篇 |
污染及防治 | 810篇 |
评价与监测 | 369篇 |
社会与环境 | 105篇 |
灾害及防治 | 11篇 |
出版年
2024年 | 14篇 |
2023年 | 59篇 |
2022年 | 107篇 |
2021年 | 143篇 |
2020年 | 176篇 |
2019年 | 124篇 |
2018年 | 138篇 |
2017年 | 167篇 |
2016年 | 240篇 |
2015年 | 262篇 |
2014年 | 466篇 |
2013年 | 509篇 |
2012年 | 472篇 |
2011年 | 497篇 |
2010年 | 295篇 |
2009年 | 342篇 |
2008年 | 298篇 |
2007年 | 371篇 |
2006年 | 419篇 |
2005年 | 321篇 |
2004年 | 261篇 |
2003年 | 273篇 |
2002年 | 229篇 |
2001年 | 195篇 |
2000年 | 200篇 |
1999年 | 147篇 |
1998年 | 136篇 |
1997年 | 97篇 |
1996年 | 91篇 |
1995年 | 68篇 |
1994年 | 63篇 |
1993年 | 45篇 |
1992年 | 31篇 |
1991年 | 16篇 |
1990年 | 14篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1973年 | 4篇 |
1971年 | 3篇 |
排序方式: 共有7357条查询结果,搜索用时 31 毫秒
741.
选择试验模型法在澳门固体废弃物管理中的应用 总被引:4,自引:0,他引:4
环境物品或环境服务的经济价值评估是环境经济学研究的前沿领域.选择试验模型法是目前国际上用于评估环境物品经济价值的一种新方法.本文以澳门的固体废弃物管理为例,探讨选择试验模型法在澳门进行环境物品经济价值评估实践的可行性.在专家咨询和小组讨论的基础上,确定垃圾分选和回收、垃圾收集频率、减小垃圾收集过程中产生的噪音和垃圾处理费为澳门固体废弃物管理的4个属性.在对澳门6个堂260名居民进行随机抽样调查的基础上,分析了澳门固体废弃物管理不同属性的价值以及固体废弃物管理不同替代方案的相对价值.结果表明,实行垃圾分选和回收利用以及减小垃圾收集过程中产生的噪声是澳门今后固体废弃物管理的合理选择. 相似文献
742.
743.
Perfluorinated Surfactants in Surface and Drinking Waters (9 pp) 总被引:1,自引:0,他引:1
Skutlarek D Exner M Färber H 《Environmental science and pollution research international》2006,13(5):299-307
Background, Aim and Scope
In this paper recent results are provided of an investigation on the discovery of 12 perfluorinated surfactants (PS) in different
surface and drinking waters (Skutlarek et al. 2006 a, Skutlarek et al. 2006 b). In the last years, many studies have reported
ubiquitous distribution of this group of perfluorinated chemicals, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic
acid (PFOA) in the environment, particularly in wildlife animal and human samples (Giesy and Kannan 2001, Houde et al. 2006,
Prevedouros et al. 2006). Perfluorinated surfactants (e.g. PFOS and PFOA) have shown different potentials for reproductory
interference and carcinogenity in animal experiments as well as partly long half-lives in humans (Guruge et al. 2006, FSA
UK 2006a, FSA UK 2006b, 3M 2005, OECD 2002, Yao and Zhong 2005). They possess compound-dependent extreme recalcitrance against
microbiological and chemical degradation and, in addition, they show variable potentials for bioaccumulation in animals and
humans (Houde et al. 2006).
Materials and Methods:
Surface and drinking water samples were collected from different sampling sites:
- Surface waters: samples taken from the rivers Rhine, Ruhr, Moehne and some of their tributaries. Further samples were taken
from the Rhine-Herne-Canal and the Wesel-Datteln-Canal.
- Drinking waters: samples taken in public buildings of the Rhine-Ruhr area.
After sample clean-up and concentration by solid-phase extraction, the perfluorinated surfactants were determined using HPLC-MS/MS.
Results:
All measured concentrations (sum of seven mainly detected components) in the Rhine river and its main tributaries (mouths)
were determined below 100 ng/L. The Ruhr river (tributary of the Rhine) showed the highest concentration (94 ng/L), but with
a completely different pattern of components (PFOA as major component), as compared with the other tributaries and the Rhine
river. Further investigations along the Ruhr river showed remarkably high concentrations of PS in the upper reaches of the
Ruhr river and the Moehne river (tributary of the Ruhr) (Ruhr: up to 446 ng/L, Moehne: up to 4385 ng/L). The maximum concentration
of all drinking water samples taken in the Rhine-Ruhr area was determined at 598 ng/L with the major component PFOA (519 ng/L).
Discussion:
The surface water contaminations most likely stem from contaminated inorganic and organic waste materials (so-called 'Abfallgemisch').
This waste material was legally applied to several agricultural areas on the upper reaches of the Moehne. Perfluorinated surfactants
could be detected in some suchlike soil samples. They contaminated the river and the reservoir belonging to it, likely by
superficial run-off over several months or probably years. Downstream, dilution effects are held responsible for decreasing
concentrations of PS in surface waters of the Moehne and the Ruhr river. In analogy to the surface water samples, PS (major
component PFOA) can be determined in many drinking water samples of the Rhine-Ruhr area where the water supplies are mainly
based on bank filtration and artificial recharge.
Conclusions:
The concentrations found in drinking waters decreased with the concentrations of the corresponding raw water samples along
the flow direction of the Ruhr river (from east to west) and were not significantly different from surface water concentrations.
This indicates that perfluorinated surfactants are at present not successfully removed by water treatment steps.
Recommendations and Perspectives:
Because of their different problematic properties (persistence, mobility, toxicity, bioaccumulation), the concentrations of
specific perfluorinated surfactants and their precursors in drinking waters and food have to be minimised. Therefore, it is
of utmost importance to take the initiative to establish suitable legal regulations (limitations/ban) concerning the production
and use of these surfactants and their precursors. Furthermore, it is indispensable to protect water resources from these
compounds. A discussion on appropriate limit values in drinking water and foodstuffs is urgently needed. Concerning the assumed
soil contamination, the corresponding regulation (Bioabfall-Verordnung 1998 – Regulation on Organic Waste 1998) should be
extended to allow the control of relevant organic pollutants. 相似文献
744.
745.
大气中芳香胺及吡啶类化合物的离子色谱法测定 总被引:3,自引:1,他引:3
采用GDX-501富集大气中芳香胺及吡啶类化合物,经沸水解吸后解吸液直接注入离子色谱仪,用紫外/可见光检测器进行测定。方法灵敏、简便,可同时测定吡啶、2-甲基吡啶、3-甲基吡啶、苯胺、邻-甲苯胺、间-甲苯胺等。当采样体积为30L时,方法的最低检出浓度范围为0.05~0.10mg/m3(吡啶~间甲苯胺),测定的回收率为84.7%~95.9%,相对标准偏差为4.0%~6.6%。 相似文献
746.
污泥堆肥样品基质复杂,其中三氯生(TCS)和三氯卡班(TCC)的提取和净化过程操作烦琐、回收率低。通过对净化条件进行优化,建立了加速溶剂萃取-在线净化-液相色谱串联质谱法检测污泥堆肥样品中TCS和TCC的分析方法,并对上海某污水厂实际污泥堆肥样品中的TCS和TCC进行定量分析。结果表明,TCS和TCC的检出限分别为0.003和0.0002μg/g,加标回收率为90.3%~99.8%,相对标准偏差(RSD)为1.2%~8.5%(n=6)。该方法样品前处理时间短、回收率高、试剂使用量少,能够满足实际污泥堆肥样品中TCS和TCC的检测要求。 相似文献
747.
为应对山区液体管道在投产过程中可能出现的气阻、超压问题,从气相运移角度出发,建立液顶气模型,研究在1个U型单元内积气形成、压缩和破碎的全过程,在此基础上,提出连接各个U型单元的气相的传递函数,探讨背压累积因素下,连续起伏管道投产过程中各个U型管段的积气情况和压力的变化,进行动态的建模和计算。以国内某原油管道的现场投产数据与模型结果进行比对。结果表明:可以更加准确地预测山区液体管道投产过程中的气相传递和压力变化过程,能为未来连续起伏大落差液体管道投产的安全稳定运行提供理论指导和技术支持。 相似文献
748.
The potentially explosive reaction of hydrogen peroxide (H2O2) and copper chloride (CuCl2) was investigated. Pressure tests revealed that the reaction was strongly temperature - dependent and can easily undergo runaway reaction. Nevertheless, there was only a slight pressure increase at the low temperatures studied or when using low concentrations of CuCl2. Under the conditions generating the slight pressure increase, hypochlorite anions (ClO−) are generated and the acidity increases. As the reaction reaches completion, ClO− disappears, and the acidity decreases. Interestingly, the addition of phosphate buffer to maintain the weakly acid conditions led to a runaway reaction, and the use of basic ClO− promoted the exothermic reaction. Based on the results, acidity has a strong impact on the reaction behaviour. 相似文献
749.
厌氧-好氧活性污泥法处理高浓度甲醇废水 总被引:5,自引:0,他引:5
介绍了厌氧一好氧活性污泥法处理电管厂高浓度甲醇废水的动态试验结果。试验结果表明:该方法处理高浓度甲醇废水,可以克服甲醇废水厌氧处理容易酸化的问题.运行稳定.抗负荷冲击性强.处理效果良好。 相似文献
750.
微电解法在废水处理中的研究及应用 总被引:15,自引:0,他引:15
概述了近20多年来国内外微电解法在染料、印染、重金属、农药、制药、油分等废水处理方面的研究应用及进展,对其处理机理进行了分析。微电解法处理速度快、效率高,主要是在处理过程中同时发生吸附作用和电化学还原作用。因此,该法是一种很有实用价值的废水处理方法。为进一步提高微电解的处理效果,提出了目前微电解法应用中存在的几个问题,并初步探讨了今后的发展动向。 相似文献