全文获取类型
收费全文 | 868篇 |
免费 | 51篇 |
国内免费 | 260篇 |
专业分类
安全科学 | 59篇 |
废物处理 | 54篇 |
环保管理 | 65篇 |
综合类 | 459篇 |
基础理论 | 188篇 |
污染及防治 | 250篇 |
评价与监测 | 34篇 |
社会与环境 | 35篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 45篇 |
2021年 | 31篇 |
2020年 | 29篇 |
2019年 | 32篇 |
2018年 | 32篇 |
2017年 | 39篇 |
2016年 | 39篇 |
2015年 | 38篇 |
2014年 | 62篇 |
2013年 | 72篇 |
2012年 | 70篇 |
2011年 | 63篇 |
2010年 | 52篇 |
2009年 | 58篇 |
2008年 | 40篇 |
2007年 | 47篇 |
2006年 | 31篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 32篇 |
2002年 | 37篇 |
2001年 | 24篇 |
2000年 | 29篇 |
1999年 | 32篇 |
1998年 | 41篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 21篇 |
1994年 | 13篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1977年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有1179条查询结果,搜索用时 250 毫秒
831.
谭绍雄 《湖南环境生物职业技术学院学报》1996,(2)
本文指出了现行银行存款余额调节表编制方法存在的问题,明确提出了银行存款余额调节表的编制方法的理论依据,建立了完整的银行存款余额调节表的编制方法体系。 相似文献
832.
城市生活垃圾治理过程的能源化技术 总被引:3,自引:0,他引:3
论述了垃圾多种治理技术以及这些技术中的能源化的关键。这些技术涉及垃圾卫生填埋、垃圾梦烧、垃圾衍生燃料技术、垃圾厌氧发酵和垃圾的热解气化等。针对中国垃圾的具体特点,对中国垃圾能源化提出一些初步方案和建议。 相似文献
833.
834.
Li H Hou S Wang W Yang L Li Y Tan J 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(4):423-428
The study is aimed to estimate the effect of different heavy metals such as Hg2+, Cd2+, Mn2+, Cr3+, Ni2+, Se2O3(2-), As2O3 water solution and combined effects of Hg2+, Mn2+, Cr3+ on lipid peroxidation in mice liver homogenate in vitro. Lipid peroxidation was determined as thiobarbituric acid-reacting materials (TBA). We select five different concentrations of selected ions for experiments. Correlations used to identify the concentration of ions associated with lipid peroxidation. The rate of lipid peroxide formation in mice liver homogenate increased with the gradual addition of alcohol. When alcohol dose was up to 0.5 ml, the rate of lipid peroxide formation was greatest. At tested concentrations, the effects of metal ions on lipid peroxidation induced by alcohol were classified into three groups, and are as follows: (1) simulative, Hg2+. (2) inhibitory, Mn2+, Cr3+, Ni2+, Se2O3(2-). (3) ambiguous, Cd2+, As2O3 water solution. When Hg2+, Mn2+ and Cr3+ were added to the mice liver homogenate with alcohol at the same time, Hg2+, Mn2+ were the main agents for the rate of alcohol induced lipid peroxidation. The simulative effect of Hg2+ on lipid peroxidation induced by alcohol indicate that alcohol-drinkers will have further health risk when they are exposed in polluted regions than others, and Mn2+, Cr3+, Ni2+, Se2O3(2-) may act as free radical scavengers and preventive remedy for alcoholism in part. Furthermore, analysis of combined effect of Hg2+Mn2+ and Cr3+ provide us a new way to estimate the combined effect of multi-materials. 相似文献
835.
X.W. Luo H.Y. Ong C. Tan S.C. Foo C.N. Ong 《Environmental monitoring and assessment》1997,44(1-3):369-374
In late August 1994, an outbreak of human pneumonic/bubonic plague was reported in Surat, India. During the epidemic, large amounts of pesticides, such as benzene-hexachloride (BHC) and other organochlorinated compounds were used to control the vector that might have transmitted the plague. In order to evaluate the extent of contamination, both environmental samples (9 water samples and 4 soil samples) and biological samples (5 blood and urine samples) were collected and analyzed for organochlorine residues. Samples were analyzed after hexane extraction by gas chromatography equipped with electron capture detector (GC-ECD), using a PTE-5 capillary column. The results showed that the levels of 1,1-(2,2-dichloroethenylidene)-bis[4-chlorobenzene] (DDE), a major metabolite of DDT, were low in environmental samples (water, soil), while BHC levels were relatively high in one of the water sample as well as two soil samples. The BHC and DDE levels in the biological samples were not higher than those reported earlier from India, except for serum DDE. Further studies are needed to evaluate the effect of long-term exposure as the present study was based on limited samples. 相似文献
836.
Yue Tan Honglei Wang Shuangshuang Shi Lijuan Shen Chen Zhang Bin Zhu Song Guo Zhijun Wu Ziyi Song Yan Yin Ankang Liu 《环境科学学报(英文版)》2020,32(10):72-84
In this study, the black carbon (BC) measurements in the atmosphere of Nanjing, China were continuously conducted from 2015 to 2018 using a Model AE-33 aethalometer. By combining dataset of PM2.5, PM10, CO, NO2, SO2, O3 and meteorological parameters, the temporal variations and the source apportionment of BC were given in this study. The results showed that the PM2.5 mass concentrations decreased in Nanjing, with an average annual rate of variation of 6.50 μg/(m3?year). Differently, the annual average concentrations of BC increased with an average annual variation rate of 214.71 ng/(m3?year). The seasonal variations showed the pattern of BC mass concentrations in winter > autumn > spring > summer. The diurnal variations of BC mass concentrations showed a double-peak in all four seasons. The first peak occurred at approximately 7:00 in spring, summer and autumn and around 8:00 in winter. The second peak took place after 18:00. The average AAE (absorption Ångström exponent) was 1.26 with a maximum of 1.35 during wintertime and the lowest (1.12) during summertime. In addition, the AAE was smaller in the daytime than that at night, with a minimum occurring between 13:00 and 14:00. BC and visibility show a good power-function relationship at different humidity levels. The average values of the visibility thresholds of the BC mass concentrations in spring, summer, autumn and winter were 1.326, 5.522, 1.340 and 0.708 μg/m3, respectively. The greater the relative humidity, the smaller the visibility threshold for the BC mass concentrations was. 相似文献
837.
Previous studies have reported that triclosan (TCS) could possess an androgenic activity. We aimed to investigate the effects of TCS on gonadal differentiation and development in the frog Pelophylax nigromaculatus, a sensitive amphibian species to androgenic chemicals. P. nigromaculatus tadpoles at stage 24 were exposed to TCS (3, 30, and 300 nmol/L) to stage 46 in a semi-static exposure system. At the end of exposure, gonadal morphology and histology, sex ratio and gonadal expression of sex-biased genes were examined in P. nigromaculatus. In each TCS treatment group, we found several individuals whose gonads exhibited morphological and/or histological abnormalities. Gonadal histological abnormalities were characterized by few oocytes and many somatic cells. Although the percentage of the individuals with abnormal gonads was low (7.8%) among all animals treated with TCS, statistical test revealed the sex ratios in the 3 and 300 nmol/L TCS treatment groups were significantly different from the solvent control. In the 30 nmol/L TCS treatment group, abnormal gonads were also observed, although the sex ratio was not changed compared with the solvent control, which was possibly due to the smaller sample size in this group. In all the TCS treatment groups, the sex ratios were not obviously male-biased, but the expression levels of some sex-biased genes were significantly altered by TCS. Altogether, our results suggest that TCS, even at environmentally relevant concentrations, could disrupt gonadal differentiation and development in P. nigromaculatus, but we are not sure whether the disrupting effects were associated with masculinization or feminization. 相似文献
838.
839.
佛山市南海城区环境空气中铅污染现状分析研究 总被引:2,自引:0,他引:2
为了解佛山市南海城区环境空气中铅污染现状,在南海城区中心设置空气质量监测点,采用重量法和电感耦合等离子体质谱法分别对空气颗粒物及不同粒径颗粒物的铅含量进行定量分析,测定结果为:TSP、PM10、PM2.5平均浓度分别是150 ug/m3、99 ug/m3、67 ug/m3,其中铅平均浓度分别是214 ng/m3、175 ng/m3、156 ng/m3.结论为:南海城区环境空气中的铅浓度达到国家环境空气质量二级标准,铅污染水平处于珠江三角洲的中游;大气中的铅主要分布在PM2.5中,机动车尾气是其主要来源. 相似文献
840.
Fluidized bed and induced crystallization technology were combined to design a new type of induced crystallization fluidized bed reactor. The added particulate matter served as crystal nucleus to induce crystallization so that the insoluble material, which was in a saturated state, could precipitate on its surface. In this study, by filling the fluidized bed with quartz sand and by adjusting water p H, precipitation of calcium carbonate was induced on the surface of quartz sand, and the removal of water hardness was achieved.With a reactor influent flow of 60 L/hr, a fixed-bed height of 0.5 m, pH value of 9.5, quartz sand nuclear diameter of 0.2–0.4 mm, and a reflux ratio of 60%, the effluent concentration of calcium hardness was reduced to 60 mg/L and 86.6% removal efficiency was achieved. The resulting effluent reached the quality standard set for circulating cooling water. Majority of the material on the surface of quartz sand was calculated to be calcium carbonate based on energy spectrum analysis and moisture content was around 15.994%. With the low moisture content, dewatering treatment is no longer required and this results to cost savings on total water treatment process. 相似文献