全文获取类型
收费全文 | 2528篇 |
免费 | 86篇 |
国内免费 | 796篇 |
专业分类
安全科学 | 131篇 |
废物处理 | 170篇 |
环保管理 | 196篇 |
综合类 | 1137篇 |
基础理论 | 452篇 |
环境理论 | 1篇 |
污染及防治 | 1035篇 |
评价与监测 | 124篇 |
社会与环境 | 54篇 |
灾害及防治 | 110篇 |
出版年
2024年 | 2篇 |
2023年 | 38篇 |
2022年 | 112篇 |
2021年 | 110篇 |
2020年 | 66篇 |
2019年 | 70篇 |
2018年 | 77篇 |
2017年 | 115篇 |
2016年 | 163篇 |
2015年 | 156篇 |
2014年 | 212篇 |
2013年 | 258篇 |
2012年 | 229篇 |
2011年 | 230篇 |
2010年 | 173篇 |
2009年 | 165篇 |
2008年 | 166篇 |
2007年 | 143篇 |
2006年 | 145篇 |
2005年 | 98篇 |
2004年 | 69篇 |
2003年 | 80篇 |
2002年 | 69篇 |
2001年 | 50篇 |
2000年 | 49篇 |
1999年 | 57篇 |
1998年 | 50篇 |
1997年 | 54篇 |
1996年 | 33篇 |
1995年 | 33篇 |
1994年 | 30篇 |
1993年 | 20篇 |
1992年 | 23篇 |
1991年 | 12篇 |
1990年 | 18篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1958年 | 2篇 |
排序方式: 共有3410条查询结果,搜索用时 15 毫秒
941.
Xiaoyan Shi Kebin He Jie Zhang Yongliang Ma Yunshan Ge Jianwei Tan 《Frontiers of Environmental Science & Engineering in China》2010,4(1):30-34
Oxygenated fuels are known to reduce particulate matter (PM) emissions from diesel engines. In this study, 100% soy methyl
ester (SME) biodiesel fuel (B100) and a blend of 10% acetal denoted by A-diesel with diesel fuel were tested as oxygenated
fuels. Particle size and number distributions from a diesel engine fueled with oxygenated fuels and base diesel fuel were
measured using an Electrical Low Pressure Impactor (ELPI). Measurements were made at ten steady-state operational modes of
various loads at two engine speeds. It was found that the geometric mean diameters of particles from SME and Adiesel were
lower than that from base diesel fuel. Compared to diesel fuel, SME emitted more ultra-fine particles at rated speed while
emitting less ultra-fine particles at maximum speed. Ultra-fine particle number concentrations of A-diesel were much higher
than those of base diesel fuel at most test modes. 相似文献
942.
943.
944.
945.
采用微乳法制备铁掺杂TiO2纳米晶(Fe-TiO2)复合体,通过热重-差热(TG-DTA)、X射线衍射(XRD)、扫描电镜(SEM)和紫外漫反射光谱(DRS)等对其结构和形态进行表征;以亚甲基蓝溶液(MB)为标准模拟降解物,对Fe-TiO2,纯TiO2和P25光催化降解性能进行评价。结果表明,Fe-TiO2的光催化活性明显〉P25,原因是Fe掺杂不仅能抑制TiO2晶粒生长,提高TiO2的热稳定性和比表面积,而且能够拓展TiO2的吸收波长范围至可见光区,提高了Ti3+离子浓度,降低了光生载流子的复合几率。 相似文献
946.
Jin Ma Li-bo Pan Qin Wang Chun-ye Lin Xiao-li Duan Hong Hou 《Environmental geochemistry and health》2018,40(1):295-301
A total of 60 children (31 males and 29 females) between the ages of 3 and 12 years were randomly selected from Lanzhou City in Gansu Province, northwest China. Hand (soil/dust) SD samples from these children were collected using hand wipes. We determined the approximate amounts of hand SD and the concentrations of three tracer soil elements (Ce, Y, and V) in these samples. The approximate amounts of hand SD ranged from 42.28 to 173.76 mg, with a median value of 85.42 mg. In addition, the mean amounts of hand SD estimated using the concentrations of Ce, Y, and V in the samples were 4.63, 3.43, and 3.42 mg, respectively. The amount of hand SD varied greatly among the age groups: primary school children had more hand SD than kindergarten children, males had more hand SD than females, and children from rural areas had more hand SD than those from urban areas. The rates of daily ingestion of hand SD for kindergarten and primary school children were estimated to be 7.73 and 6.61 mg/day, respectively. 相似文献
947.
基于非本地物种的毒性数据推导出的水质基准一直存在争议,质疑者提出应有针对不同生物区系的水质基准。而这个问题在中国尤为突出。本文作者搜集了38种污染物对本地物种和非本地物种的毒性数据,比较了这些生物的HC5和物种敏感度分布,结果显示,基于非本地物种推导的水质基准有74%的确定性可以有效保护中国的水生态系统。如果采用评价因子(AF=5)来校正基准,那么可以获得90%的确定性。
精选自Xiaowei Jin, Zijian Wang, Yeyao Wang, Yibing Lv, Kaifeng Rao, Wei Jin, John P. Giesy and Kenneth M. Y. Leung. Do water quality criteria based on nonnative species provide appropriate protection for native species? Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2985
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2985/full 相似文献
948.
Xiao-song Zha Yan Liu Xiang Liu Qiang Zhang Rui-hua Dai Ling-wen Ying Jin Wu Jing-ting Wang Luming Ma 《Environmental science and pollution research international》2014,21(4):2714-2723
This study aims to investigate the influence of the coexistence of halogen ions (bromide/iodide) and biological source matters on the speciation and yield of trihalomethanes (THMs), haloacetic acids (HAAs), and N-nitrosodimethylamine (NDMA) during the ozonation and subsequent chlorination of water. The results show that the concentrations of brominated THMs and iodinated THMs increased with increasing bromide and iodide concentration. These results may be attributed to the higher reactivity of hypobromous acid and hypoiodous acid generated from the ozonation and subsequent chlorination in the presence of bromide or iodide ions. The presence of bromide increased the species of brominated HAAs. There was a shift from chlorinated HAAs to brominated HAAs after increasing the concentration of bromide. The effect of iodide on HAA formation was more complex than bromide. For most samples, the concentration of total HAAs (T-HAAs) increased to the maximum and then decreased with increasing iodide concentration. The components of the organic precursors also significantly influenced the formation of brominated and iodinated disinfection by-products (Br-DBPs and I-DBPs). Humic acids produced more CHBr3 (596.60 μg/L) than other organic materials. Microcystis aeruginosa cells produced the most tribromoacetic acid (TBAA, 84.16 μg/L). Furthermore, the yield of NDMA decreased with increasing bromide concentration, indicating that the formation of NDMA was inhibited by the high concentration of bromide. 相似文献
949.
Yang Li Hua Ping Zhi-Hong Ma Li-Gang Pan 《Environmental science and pollution research international》2014,21(8):5547-5553
According to the data from authoritative sources, 1,400 sudden leakage accidents occurred in China during 2006 to 2011 were investigated, in which, 666 accidents were used for statistical characteristic abstracted with no or little damage. The research results were as follows: (1) Time fluctuation: the yearly number of sudden leakage accidents is shown to be decreasing from 2006 to 2010, and a slightly increase in 2011. Sudden leakage accidents occur mainly in summer, and more than half of the accidents occur from May to September. (2) Regional distribution: the accidents are highly concentrated in the coastal area, in which accidents result from small and medium-sized enterprises more easily than that of the larger ones. (3) Pollutants: hazardous chemicals are up to 95 % of sudden leakage accidents. (4) Steps: transportation represents almost half of the accidents, followed by production, usage, storage, and discard. (5) Pollution and casualties: it is easy to cause environmental pollution and casualties. (6) Causes: more than half of the cases were caused by human factor, followed by management reason, and equipment failure. However, sudden chemical leakage may also be caused by high temperature, rain, wet road, and terrain. (7) The results of principal component analysis: five factors are extracted by the principal component analysis, including pollution, casualties, regional distribution, steps, and month. According to the analysis of the accident, the characteristics, causes, and damages of the sudden leakage accident will be investigated. Therefore, advices for prevention and rescue should be acquired. 相似文献
950.