全文获取类型
收费全文 | 1317篇 |
免费 | 214篇 |
国内免费 | 260篇 |
专业分类
安全科学 | 437篇 |
废物处理 | 40篇 |
环保管理 | 210篇 |
综合类 | 639篇 |
基础理论 | 114篇 |
环境理论 | 1篇 |
污染及防治 | 118篇 |
评价与监测 | 103篇 |
社会与环境 | 76篇 |
灾害及防治 | 53篇 |
出版年
2024年 | 13篇 |
2023年 | 38篇 |
2022年 | 70篇 |
2021年 | 79篇 |
2020年 | 78篇 |
2019年 | 82篇 |
2018年 | 82篇 |
2017年 | 77篇 |
2016年 | 103篇 |
2015年 | 79篇 |
2014年 | 93篇 |
2013年 | 162篇 |
2012年 | 150篇 |
2011年 | 121篇 |
2010年 | 90篇 |
2009年 | 67篇 |
2008年 | 49篇 |
2007年 | 73篇 |
2006年 | 56篇 |
2005年 | 49篇 |
2004年 | 41篇 |
2003年 | 27篇 |
2002年 | 15篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 15篇 |
1998年 | 9篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1791条查询结果,搜索用时 265 毫秒
101.
Xiaoli Wang 《中国人口.资源与环境(英文版)》2017,15(1):80-86
As the main contribution of China’s carbon emissions, low-carbon production in industrial firms becomes an inevitable choice, and industrial firm employees’ attitudes on low-carbon new technology directly influence the results of low-carbon production. Based on the Unified Theory of Acceptance and Use of Technology model, structural equation modeling was used to analyze the main factors influencing firm staff to accept low-carbon new technology. The study reveals that the employee’s social impact, performance expectation, effort expectations and convenient conditions, and employee characteristics are all main factors affecting their acceptance attitudes on low-carbon new technology. And social influence has the largest effect on employees’ acceptance attitudes toward low-carbon new technology. Accordingly, relevant policy recommendations are put forward for the future research direction. 相似文献
102.
采用盐析分相微萃取—高效液相色谱法同时测定水中3种含氯除草剂,建立并优化了反相离子对液相色谱条件,考察了萃取剂种类、盐析剂的种类和加入量及试样pH对萃取效果的影响。对氯苯氧乙酸、2,4-二氯苯氧乙酸和2,4-滴丁酯的质量浓度在0.1~100.0mg/L内与色谱峰面积呈良好的线性关系,相关系数不低于0.9992。平均回收率分别为96.29%、79.16%和70.21%,相对标准偏差小于5.3%。该方法操作简便、绿色环保,适合于水中含氯除草剂的测定。 相似文献
103.
基于数据包络分析(DEA)的点源水污染物排放指标初始分配方法,是将基于DEA的线性规划评价方法进行改进,从而使其适用于评价企业的水环境绩效,并依此进行排污指标初始分配。将非期望产出作为投入指标处理,构造了5输入1输出的规模可变DEA模型,并以南京市280家企业的COD排放指标初始分配为例进行了分析。结果表明,方法的模拟分配结果在公平的基础上,反映了企业的环境效率,效率越高,可得到的COD排放指标也越高,这将对企业治污起到激励作用,分配方法具有一定的可操作性;对案例企业进行分组并实行组内参评,基本可以避免部分极值原始数据对评价结果的影响,得到的COD排放指标分配结果也更为合理。 相似文献
104.
A full scale field study has been carried out in order to test and evaluate the use of slags from high-alloy steel production as the construction materials for a final cover of an old municipal landfill. Five test areas were built using different slag mixtures within the barrier layer (liner). The cover consisted of a foundation layer, a liner with a thickness of 0.7 m, a drainage layer of 0.3 m, a protection layer of 1.5 m and a vegetation layer of 0.25 m. The infiltration varied depending on the cover design used, mainly the liner recipe but also over time and was related to seasons and precipitation intensity. The test areas with liners composed of 50% electric arc furnace (EAF) slag and 50% cementitious ladle slag (LS) on a weight basis and with a proper consistence of the protection layer were found to meet the Swedish infiltration criteria of ?50 l (m2 a)?1 for final covers for landfills for non-hazardous waste: the cumulative infiltration rates to date were 44, 19 and 0.4 l (m2 a)?1 for A1, A4 and A5, respectively. Compared to the precipitation, the portion of leachate was always lower after the summer despite high precipitation from June to August. The main reason for this is evapotranspiration but also the fact that the time delay in the leachate formation following a precipitation event has a stronger effect during the shorter summer sampling periods than the long winter periods. Conventional techniques and equipment can be used but close cooperation between all involved partners is crucial in order to achieve the required performance of the cover. This includes planning, method and equipment testing and quality assurance. 相似文献
105.
Dragan R. Milićević Verica B. Jurić Srđan M. Stefanović Slavica M. Vesković-Moračanin Saša D. Janković 《Journal of environmental science and health. Part. B》2013,48(8):781-787
This study was undertaken to compare two different analytical methods for the determination and confirmation of ochratoxin A (OTA) in blood serum, kidney and liver of pigs. Sample clean-up was based on liquid-liquid phase extraction. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined either with fluorescence detection (FL) or electro spray ionization (ESI+) tandem mass spectrometry (MS–MS). Comparative method evaluation was based on the investigation of 90 samples of blood serum, kidney and liver per animal originating from different regions of Serbia. The analytical results are discussed in view of the respective method validation data and the corresponding experimental protocols. In general, analytical data obtained with (LC–MS–MS) liquid chromatography electro spray tandem mass spectro metry detection offered comparable good results at the sub-ppb concentration level. The results indicate that the liquid chromatography electro spray tandem mass spectrometric (LC-MS/MS) method was more specific and sensitive for the analysis and confirmation of ochratoxin A in pig tissues then high pressure liquid chromatography (HPLC) method after methylation of OTA. 相似文献
106.
107.
对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。 相似文献
108.
Shalamu Abudu J. Phillip King Zhuping Sheng 《Journal of the American Water Resources Association》2012,48(1):10-23
Abudu, S., J.P. King, Z. Sheng, 2011. Comparison of the Performance of Statistical Models in Forecasting Monthly Total Dissolved Solids in the Rio Grande. Journal of the American Water Resources Association (JAWRA) 48(1): 10‐23. DOI: 10.1111/j.1752‐1688.2011.00587.x Abstract: This paper presents the application of autoregressive integrated moving average (ARIMA), transfer function‐noise (TFN), and artificial neural networks (ANNs) modeling approaches in forecasting monthly total dissolved solids (TDS) of water in the Rio Grande at El Paso, Texas. Predictability analysis was performed between the precipitation, temperature, streamflow rates at the site, releases from upstream reservoirs, and monthly TDS using cross‐correlation statistical tests. The chi‐square test results indicated that the average monthly temperature and precipitation did not show significant predictability on monthly TDS series. The performances of one‐ to three‐month‐ahead model forecasts for the testing period of 1984‐1994 showed that the TFN model that incorporated the streamflow rates at the site and Caballo Reservoir release improved monthly TDS forecasts slightly better than the ARIMA models. Except for one‐month‐ahead forecasts, the ANN models using the streamflow rates at the site as inputs resulted in no significant improvements over the TFN models at two‐month‐ahead and three‐month‐ahead forecasts. For three‐month‐ahead forecasts, the simple ARIMA showed similar performance compared to all other models. The results of this study suggested that simple deseasonalized ARIMA models could be used in one‐ to three‐month‐ahead TDS forecasting at the study site with a simple, explicit model structure and similar model performance as the TFN and ANN models for better water management in the Basin. 相似文献
109.
Plant steroid hormones produced under Ni stress are involved in the regulation of metal uptake and oxidative stress in Brassica juncea L 总被引:3,自引:0,他引:3
Brassinosteroids (BRs) are involved in the amelioration of various biotic and abiotic stresses. With an aim to explore the role of BRs under heavy metal stress, plants of Brassica juncea L. were grown in pots. The plants were subjected to various concentrations of Nickel metal (0.0, 0.2, 0.4 and 0.6 mM) and harvested on 60th day in order to observe the expression of these hormones. The isolated BRs from the leaves of Brassica plants characterized by GC-MS include 24-Epibrassinolide (24-EBL), Castasterone, Dolicholide and Typhasterole. The effect of isolated 24-EBL was studied on Ni metal uptake and antioxidative defense system in 60 d old plants of Brassica. It was observed that 24-EBL significantly increased the activities of stress ameliorating enzymes and lowered the metal uptake in plants. This is the first report in B. juncea L. plants showing the expression of BRs under metal treatments and effect of the isolated 24-EBL on metal uptake and in oxidative stress management. 相似文献
110.
Moe MK Huber S Svenson J Hagenaars A Pabon M Trümper M Berger U Knapen D Herzke D 《Chemosphere》2012,89(7):869-875
For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by 1H, 13C and 19F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility. 相似文献