全文获取类型
收费全文 | 370篇 |
免费 | 51篇 |
国内免费 | 184篇 |
专业分类
安全科学 | 32篇 |
废物处理 | 67篇 |
环保管理 | 54篇 |
综合类 | 253篇 |
基础理论 | 51篇 |
污染及防治 | 129篇 |
评价与监测 | 17篇 |
社会与环境 | 2篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 21篇 |
2019年 | 9篇 |
2018年 | 14篇 |
2017年 | 21篇 |
2016年 | 32篇 |
2015年 | 37篇 |
2014年 | 34篇 |
2013年 | 41篇 |
2012年 | 51篇 |
2011年 | 42篇 |
2010年 | 35篇 |
2009年 | 30篇 |
2008年 | 24篇 |
2007年 | 16篇 |
2006年 | 35篇 |
2005年 | 16篇 |
2004年 | 20篇 |
2003年 | 23篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1971年 | 3篇 |
排序方式: 共有605条查询结果,搜索用时 31 毫秒
21.
Using Ion-Exchange Resins to Study Soil Response to Experimental Watershed Acidification 总被引:1,自引:0,他引:1
Szillery JE Fernandez IJ Norton SA Rustad LE White AS 《Environmental monitoring and assessment》2006,116(1-3):383-398
Ion-exchange resins (IER) offer alternative approaches to measuring ionic movement in soils that may have advantages over
traditional approaches in some settings, but more information is needed to understand how IER compare with traditional methods
of measurement in forested ecosystems. At the Bear Brook Watershed in Maine (BBWM), one of two paired, forested watersheds
is treated bi-monthly with S and N (28.8 and 25.2kgha−1yr−1 of S and N, respectively). Both IER and ceramic cup tension lysimeters were used to study soil solution responses after ∼11
years of treatment. Results from both methods showed treatments resulted in the mobilization of base cations and Al, and higher
SO4—S and inorganic N in the treated watershed. Both methods indicated similar differences in results associated with forest
type (hardwoods versus softwoods), a result of differences in litter quality and atmospheric aerosol interception capacity.
The correlation between lysimeter and IER data for individual analytes varied greatly. Significant correlations were evident
for Na (r=0.75), Al (r=0.65), Mn (r=0.61), Fe (r=0.57), Ca (r=0.49), K (r=0.41) and NO3—N (r=0.59). No correlation was evident between IER and soil solution data for NH4—N and Pb. Both IER and soil solution techniques suggested similar interpretations of biogeochemical behavior in the watershed. 相似文献
22.
Chlorination Byproducts in Drinking Water Produced from Thermal Desalination in United Arab Emirates 总被引:1,自引:0,他引:1
Oil activities in the Arabian Gulf can potentially affect the quality of the intake water available for coastal desalination plants. This paper addresses such situation by investigating the quality of intake water and desalinated water produced by a desalination plant located near a coastal industrial complex in United Arab Emirates (UAE). Analyses of the organic compounds on the intake seawater reported non-detected levels in most samples for the three tested organic groups; namely Polyaromatic Hydrocarbons (PAHs), Phenols, and Polychlorinated Biphenyls (PCBs). Trihalomethanes (THMs) and Haloacetic Acids (HAAs) were also tracked in the intake sea water, throughout the desalination processes, and in the final produced drinking water, to evaluate the undertaken pre- and post chlorination practices. The levels of considered Chlorination Byproducts (CBPs) were mostly found below the permissible international limits with few exceptions showing tangible levels of bromoform in the intake seawater and in the final produced drinking water as well. Lab-controlled experiments on the final produced distillate showed little contribution of its blending with small percentage of seawater upon the formation of trihalomethane and in particular, bromoform. Such results indicate that the organic precursors originated in the seawater are responsible for bromoform formation in the final distillate. 相似文献
23.
新型树脂对氯酚类物质的吸附研究 总被引:4,自引:0,他引:4
合成了乙酰氯修饰树脂NDA-O,与Purolite公司的MN-200相比,合成的树脂比表面积较小,但酸性官能团较多.用两种树脂吸附2-氯酚、4-氯酚和2,4-二氯酚发现,吸附结果可以用Langmuir和Freundlich等温吸附方程很好地模拟,合成的NDA-O对3种氯酚类物质的吸附能力优于MN-200.两种树脂对氯酚类物质的吸附量随着温度的升高而减少,表明吸附是放热过程,同时对氯酚类物质的吸附焓变随着吸附量的增大而减小.对同一种树脂来说,吸附量随着氯代程度的增加而增加,取代氯数相同的时候,吸附量与吸附质的K..成正相关.进一步研究了pH对吸附的影响,在pH大于9时,3种氯酚类物质的吸附量均急剧减少. 相似文献
24.
25.
Transformations of particles, metal elements and natural organic matter in different water treatment processes 总被引:1,自引:0,他引:1
YAN Ming-quan WANG Dong-sheng SHI Bao-you WEI Qun-shan QU Jiu-hui TANG Hong-xiao 《环境科学学报(英文版)》2007,19(3):271-277
Characterizing natural organic matter (NOM), particles and elements in different water treatment processes can give a useful information to optimize water treatment operations. In this article, transformations of particles, metal elements and NOM in a pilot-scale water treatment plant were investigated by laser light granularity system, particle counter, glass-fiber membrane filtration, inductively coupled plasma-optical emission spectroscopy, ultra filtration and resin absorbents fractionation. The results showed that particles, NOM and trihalomethane formation precursors were removed synergistically by sequential treatment of different processes. Preozonation markedly changed the polarity and molecular weight of NOM, and it could be conducive to the following coagulation process through destabilizing particles and colloids; mid-ozonation enhanced the subsequent granular activated carbon (GAC) filtration process by decreasing molecular weight of organic matters. Coagulation-flotation and GAC were more efficient in removing fixed suspended solids and larger particles; while sand-filtration was more efficient in removing volatile suspended solids and smaller particles. Flotation performed better than sedimentation in terms of particle and NOM removal. The type of coagulant could greatly affect the performance of coagulation-flotation. Pre-hydrolyzed composite coagulant (HPAC) was superior to FeCl3 concerning the removals of hydrophobic dissolved organic carbon and volatile suspended solids. The leakages of flocs from sand-filtration and microorganisms from GAC should be mitigated to ensure the reliability of the whole treatment system. 相似文献
26.
WANG Hai-ling FEI Zheng-hao CHEN Jin-long ZHANG Quan-xing XU Yan-hua 《环境科学学报(英文版)》2007,19(11):1298-1304
The adsorption behavior of p-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature.Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm.The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest,which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid.The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid.Thermodynamic studies suggested the exothermic,spontaneous physical adsorption process.Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step. 相似文献
27.
载钯螯合树脂的制备、表征及其降解多溴联苯醚的初步研究 总被引:1,自引:0,他引:1
以聚丙烯醛-异烟酰腙螯合树脂为高分子载体, 利用其活性基团对钯的选择性富集分离性能, 将金属元素钯键合到高分子载体上, 制备一种含钯树脂材料(树脂1), 并进一步原位还原得到还原态的载钯树脂(树脂2)。利用红外光谱、扫描电镜和X射线衍射等对以上2种含钯树脂材料进行了分析表征,并考察了它们对持久性有机污染物(POPs)多溴联苯醚(PBDEs)的脱溴降解性能。结果表明,2种树脂对BDE209均有降解活性, 其中树脂1的降解性能比树脂2的降解性能要高, 树脂中钯的氧化形态可能对BDE209的催化降解起主要作用。 相似文献
28.
J. Medellín-Azuara L.G. Mendoza-Espinosa J.R. Lund J.J. Harou R.E. Howitt 《Journal of environmental management》2009,90(11):3470-3478
This paper uses simple hydro-economic optimization to investigate a wide range of regional water system management options for northern Baja California, Mexico. Hydro-economic optimization models, even with parsimonious model formulations, enable investigation of promising water management portfolios for supplying water to agricultural, environmental and urban users. CALVIN, a generalized hydro-economic model, is used in a case study of Baja California. This drought-prone region faces significant challenges to supply water to agriculture and its fast growing border cities. Water management portfolios include water markets, wastewater reuse, seawater desalination and infrastructure expansions. Water markets provide the flexibility to meet future urban demands; however conveyance capacity limits their use. Wastewater reuse and conveyance expansions are economically promising. At current costs desalination is currently uneconomical for Baja California compared to other alternatives. Even simple hydro-economic models suggest ways to increase efficiency of water management in water scarce areas, and provide an economic basis for evaluating long-term water management solutions. 相似文献
29.
研究了PAN—S浸渍树脂对Co^2+的吸附性能。Co^2+吸附pH值范围为4.7—9.2,最佳pH值为5.4;达到最大吸附容量需25min,树脂对Co^2+平衡吸附容量是98mg/g干树脂,达到最大吸附容量平衡时用0.1mol/L的HNO,洗脱,洗脱率达98%。该方法建立了PAN—S-树脂富集一分离钴离子的分光光度测定方法,结果令人满意。 相似文献
30.