全文获取类型
收费全文 | 3078篇 |
免费 | 99篇 |
国内免费 | 851篇 |
专业分类
安全科学 | 186篇 |
废物处理 | 189篇 |
环保管理 | 242篇 |
综合类 | 1324篇 |
基础理论 | 598篇 |
污染及防治 | 1073篇 |
评价与监测 | 145篇 |
社会与环境 | 109篇 |
灾害及防治 | 162篇 |
出版年
2024年 | 1篇 |
2023年 | 45篇 |
2022年 | 148篇 |
2021年 | 106篇 |
2020年 | 65篇 |
2019年 | 78篇 |
2018年 | 136篇 |
2017年 | 116篇 |
2016年 | 164篇 |
2015年 | 197篇 |
2014年 | 184篇 |
2013年 | 274篇 |
2012年 | 202篇 |
2011年 | 241篇 |
2010年 | 189篇 |
2009年 | 164篇 |
2008年 | 193篇 |
2007年 | 194篇 |
2006年 | 150篇 |
2005年 | 105篇 |
2004年 | 127篇 |
2003年 | 119篇 |
2002年 | 89篇 |
2001年 | 144篇 |
2000年 | 88篇 |
1999年 | 92篇 |
1998年 | 67篇 |
1997年 | 62篇 |
1996年 | 58篇 |
1995年 | 55篇 |
1994年 | 33篇 |
1993年 | 39篇 |
1992年 | 32篇 |
1991年 | 25篇 |
1990年 | 16篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1958年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有4028条查询结果,搜索用时 15 毫秒
941.
Micro-organism with efficient desulfurization performance is a key factor in the biological desulfurization technology. This study aimed to seek such a sulfur-oxidizing strain and understand its desulfurization mechanism. Wastewater in a sewage station of natural gas purification plant was used to screen the sulfide-oxidizing strain, and to identify it based on sequence similarity analysis of 16S rDNA and the morphological characteristics. Thiosulfate was used as substrate for investigating the sulfur oxidation performance and salinity tolerance; the OD600, content change of thiosulfate, sulfate, sulfur, pH and total alkalinity in the cultural system were also investigated. The strain DS-B was found to share the highest sequence similarity with Thioalkalivibrio thiocyanoxidans ARh2, therefore determined as Thioalkalivibrio. At the optimum temperature of 35 °C for growth and degradation, the removal efficiency of thiosulfate could reach 98.7% after 7 days. Strain DS-B had strong resistance to thiosulfate, and the optimal concentration of S2O32- was 2 × 104 mg/L. The analysis for sulfur oxides showed that it could oxidize thiosulfate by the pathway of S2O32-→SO42- / S2O32- → S → SO42-. Therefore the strain DS-B is a sulfur-oxidizing bacterium with great application prospect for its strong salt tolerance and conspicuous removal capability for thiosulfate. 相似文献
942.
The physical properties of gas and water are important in usage of gas reservoirs with water and water-soluble gas reservoirs. According to the Petroleum and Natural Gas Industry Standards SY/T5542-2009 of the People's Republic of China, by applying the crude oil multistage degassing method from the “Test Method for Reservoir fluid Physical Properties” and the formation water high-pressure property testing method described in the “Theory and Application of Reservoir Fluid Phase”, this investigation employed a Ruska 2370–601A phase analyzer to obtain data regarding gas–water ratios, water volume factors, compressibility coefficients, and densities. The results showed curve trends with changes in the temperature and pressure. The gas–water ratio was compared to the gas content of subsurface samples from the X water-soluble gas reservoir, suggesting that these findings might help in the analysis of water-soluble gas reservoirs. 相似文献
943.
Particles from ambient air and combustion sources including vehicle emission, coal combustion and biomass burning were collected and chemically pretreated with the purpose of obtaining isolated BC (black carbon) samples. TEM (transmission electron microscopy) results indicate that BC from combustion sources shows various patterns, and airborne BC appears spherical and about 50 nm in diameter with a homogeneous surface and turbostratic structure. The BET (Barrett–Emmett–Teller) results suggest that the surface areas of these BC particles fall in the range of 3–23 m2/g, with a total pore volume of 0.03–0.05 cm3/g and a mean pore diameter of 7–53 nm. The nitrogen adsorption–desorption isotherms are indicative of the accumulation mode and uniform pore size. O2-TPO (temperature programmed oxidation) profiles suggest that the airborne BC oxidation could be classified as the oxidation of amorphous carbon, which falls in the range of 406–490°C with peaks at 418, 423 and 475°C, respectively. Generally, the BC characteristics and source analysis suggest that airborne BC most likely comes from diesel vehicle emission at this site. 相似文献
944.
我国环保产业研究现状分析——基于宏观视角的文献述评 总被引:1,自引:0,他引:1
通过文献研究法,基于宏观视角对我国环保产业研究成果进行梳理。当前,我国的环保产业研究成果初具规模,研究重点在于环保产业的现状分析、问题探讨以及对策研究,包括环保产业各主体间博弈均衡、环保产业的技术支持、投融资机制等内容。未来环保产业研究应注意环保产业竞争力的科学评价、环保产业主体间的良性互动及其合力的达成以及环保技术评价和兑现。 相似文献
945.
采用危险与可操作性(HAZOP)方法分析了石脑油储罐废气排放系统工艺变更的危害因素,特别对废气排放系统的控制参数,给出了逆流、超温、超压、低压/真空等偏差的HAZOP分析结果,并针对高风险的偏差提出了相应的建议措施. 相似文献
946.
Studying developmental neurotoxic effects of bisphenol A (BPA) using embryonic stem cells 总被引:1,自引:0,他引:1
There is little to no toxicity information regarding thousands of chemicals to which people are exposed daily. In fact, of the 84,000 chemicals listed in the United States Toxic Substances Control Act Inventory, there is limited information available on their effects on neural development (Betts, 2010 and US EPA, 2015). The number of chemicals tested remains low due to the high cost of conducting multi-generational animal studies and the lack of alternative testing methods. 相似文献
947.
Rice: Reducing arsenic content by controlling water irrigation 总被引:2,自引:0,他引:2
<正>Arsenic has long been recognized as a poison.Arsenic in water supplies that are used for both drinking and crop irrigation can expose many people chronically to elevated levels of arsenic.The main health concern for chronic exposure to arsenic is the development of cancer.Although the World Health Organization(WHO)recommends that total arsenic in drinking water should be under 10μg/L(or 10 ppb),(WHO,2011),some regions 相似文献
948.
Hua Wang Yun Zhu Carey Jang Che-Jen Lin Shuxiao Wang Joshua S. Fu Jian Gao Shuang Deng Junping Xie Dian Ding Xuezhen Qiu Shicheng Long 《环境科学学报(英文版)》2015
Due to the increasingly stringent standards, it is important to assess whether the proposed emission reduction will result in ambient concentrations that meet the standards. The Software for Model Attainment Test—Community Edition (SMAT-CE) is developed for demonstrating attainment of air quality standards of O3 and PM2.5. SMAT-CE improves computational efficiency and provides a number of advanced visualization and analytical functionalities on an integrated GIS platform. SMAT-CE incorporates historical measurements of air quality parameters and simulated air pollutant concentrations under a number of emission inventory scenarios to project the level of compliance to air quality standards in a targeted future year. An application case study of the software based on the U.S. National Ambient Air Quality Standards (NAAQS) shows that SMAT-CE is capable of demonstrating the air quality attainment of annual PM2.5 and 8-hour O3 for a proposed emission control policy. 相似文献
949.
<正>Microcystins are potent toxins,produced naturally by cyanobacteria(blue green algae),and they present significant threats to human and animal health(WHO,1999;Chorus,2001;Carmichael et al.,2001;Falconer,2005;IARC,2010;Ma et al.,2015).These cyclic peptides consist of five common core amino 相似文献
950.