全文获取类型
收费全文 | 5616篇 |
免费 | 448篇 |
国内免费 | 1814篇 |
专业分类
安全科学 | 599篇 |
废物处理 | 252篇 |
环保管理 | 472篇 |
综合类 | 3519篇 |
基础理论 | 825篇 |
污染及防治 | 1283篇 |
评价与监测 | 322篇 |
社会与环境 | 313篇 |
灾害及防治 | 293篇 |
出版年
2024年 | 28篇 |
2023年 | 98篇 |
2022年 | 262篇 |
2021年 | 229篇 |
2020年 | 245篇 |
2019年 | 198篇 |
2018年 | 205篇 |
2017年 | 286篇 |
2016年 | 234篇 |
2015年 | 294篇 |
2014年 | 409篇 |
2013年 | 461篇 |
2012年 | 487篇 |
2011年 | 496篇 |
2010年 | 430篇 |
2009年 | 401篇 |
2008年 | 416篇 |
2007年 | 378篇 |
2006年 | 364篇 |
2005年 | 301篇 |
2004年 | 212篇 |
2003年 | 209篇 |
2002年 | 191篇 |
2001年 | 155篇 |
2000年 | 148篇 |
1999年 | 112篇 |
1998年 | 86篇 |
1997年 | 97篇 |
1996年 | 107篇 |
1995年 | 83篇 |
1994年 | 71篇 |
1993年 | 62篇 |
1992年 | 43篇 |
1991年 | 19篇 |
1990年 | 22篇 |
1989年 | 13篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有7878条查询结果,搜索用时 437 毫秒
541.
Jianteng Sun Jiyan Liu Qian Liu Ting Ruan Miao Yu Yawei Wang Thanh Wang Guibin Jiang 《Chemosphere》2013,90(9):2388-2395
Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) along with methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have been frequently identified as natural compounds in marine environment and also assumed as metabolites of PBDEs. In the present study, nine OH-PBDE, nine MeO-PBDE and 10 PBDE congeners were studied in the sewage sludge collected from 36 municipal wastewater treatment plants (WWTPs) in 27 cities of China. The results suggest that OH-PBDEs and PBDEs are ubiquitous in sewage sludge in China, however, methoxylated PBDEs were not detectable. Composition profiles of detected OH-PBDE congeners were different depending on the sampling location. ΣOH-PBDEs in WWTPs sludge ranged from 0.04 to 2.24 ng g?1 dry weight (mean: 0.35 ng g?1 dry weight). The total amount of the two most prominent congeners (6-OH-BDE-47 + 2′-OH-BDE-68) accounted for about 53.3–100% of the sum of all six identified congeners. A significant linear relationship was found between 6-OH-BDE-47 and 2′-OH-BDE-68. A distinct geographical distribution of ΣOH-PBDEs was observed with greater concentrations of OH-PBDEs at coastal areas than inland regions in China. 相似文献
542.
高效阿特拉津降解菌株DNS10降解条件优化 总被引:2,自引:0,他引:2
从长期施用阿特拉津的寒地黑土耕层(0~10 cm)土壤中筛选到一株能以除草剂阿特拉津为氮源生长的降解菌株,结合16S rRNA序列分析结果,将该菌株命名为Arthrobacter sp.DNS10。在接种量为108CFU/mL的条件下,菌株DNS10在24 h内对100 mg/L阿特拉津的降解率为99.41%。单因子实验结果表明,菌株DNS10适宜生长和降解的条件范围是:温度25~35℃,pH值5.0~8.0,培养液盐度0.1%~2%,对阿特拉津最大耐受浓度可达1 200 mg/L。正交实验法进一步表明,该菌株保持较好生长及降解能力的最优方案是温度30℃,pH值7.5,培养液盐度0.5%。影响其降解能力的环境因素的主次顺序依次是:温度>盐度>pH值。 相似文献
543.
利用沉水植物生长期收割进行富营养化水体生态管理的实地研究 总被引:2,自引:0,他引:2
在以再生水为补水水源的圆明园玉玲珑水域进行沉水植物收割实验,自2011年4—12月间每隔半个月监测一次水质。结果表明,通过在生长期收割沉水植物,玉玲珑水体TP、SRP、TN、NH4+-N、NO3--N和COD的平均浓度可维持在0.1、0.04、0.86、0.1、0.32和18 mg/L左右,水质保持在Ⅲ类至Ⅳ类地表水之间;与之对照的不收割沉水植物的玉玲珑进水口水域,9月沉水植物开始死亡腐烂,TP、SRP、TN、NH4+-N最高分别可达0.5、0.1、2.4和0.60 mg/L;作为对照的另一以挺水植物为主的水域,水质普遍劣于有大量沉水植物生长的水域,TP、SRP、TN、NH4+-N最高分别可达1.2、0.60、6.1和0.61mg/L。圆明园的实地实验表明,沉水植物有很强的净化水质作用,通过生长期收割,能够进一步强化其水质净化作用,可以作为一项对富营养化水体进行生态管理的有效措施进行推广。 相似文献
544.
545.
建立了利用组合单标多点校正和英蓝超滤单元的离子色谱法测定地表水中F-、C1-、NO3-、S0424—4-种离子的方法,方法操作简便,灵敏度高,线性范围广,抗干扰能力强,可同时快速测定不同数量级浓度的离子,降低了配置标准品和样品前处理的复杂性,减少了因前处理带来的干扰。 相似文献
546.
Effect of humic acids on physicochemical property and Cd(II) sorption of multiwalled carbon nanotubes 总被引:1,自引:0,他引:1
Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 μM zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H2O2. The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn2+ level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H2O2 synergistically increased the intracellular Zn2+ level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient. 相似文献
547.
Effect of inoculation methods on the composting efficiency of municipal solid wastes 总被引:3,自引:0,他引:3
Four types of inoculation methods were studied during the composting of municipal solid wastes and dry grass (MSWG). The methods included a control group as well as initial-stage, two-stage, and multi-stage inoculations. Fulvic acids were extracted from the composting materials and characterized by spectroscopic techniques. The results showed that inoculation of microbes in MSWG enhanced the biodegradation of aliphatics, proteins, and polysaccharides. The inoculation also increased the molecular weight, humic- and fulvic-like compound content, as well as humification degree of the composting products. The inoculation of microbes in MSWG significantly improved composting process and efficiency. The improvement efficiency was in the order of initial-stage < two-stage < multi-stage inoculations. Inoculation of microbes based on composting organic matter composition and temperature enhanced composting efficiency. 相似文献
548.
Phytoavailability and geospeciation of cadmium in contaminated soil remediated by Rhodobacter sphaeroides 总被引:1,自引:0,他引:1
A microorganism was isolated from oil field injection water and identified as Rhodobacter sphaeroides. It was used for the remediation of simulated cadmium-contaminated soil. The phytoavailability of Cd was investigated through wheat seedling method to determine the efficiency of remediation. It was found that after remediation, the accumulation of Cd in wheat roots and leaves decreased by 67% and 53%, respectively. The Cd speciation in soil was determined with Tessier extraction procedure. It was found that the total Cd content in soil did not change during the experiments, but the geo-speciation of Cd changed remarkably. Among the five fractions, the concentration of exchangeable phases decreased by 27-46% and that of the phases bound to Fe-Mn oxides increased by 22-44%. The decrease of Cd accumulation in wheat showed significant positive correlation with the decrease of exchangeable phases. It could be concluded that the remediation of R. sphaeroides was carried out through the conversion of Cd to more stable forms. The decrease of sulfate concentration in supernatant indicated that the R. sphaeroides consumed sulfate. 相似文献
549.
Jiang Y Xu H Zhang W Zhu M Al-Rasheid KA 《Environmental science and pollution research international》2012,19(5):1747-1754
Introduction
In order to reveal the potential relationships between body-size patterns of microzooplankton and environmental status, the spatial patterns in body-size spectra of ciliated zooplanktons were studied based on an annual dataset in a bay of the Yellow Sea, northern China.Materials and methods
A total of 120 samples were collected at a depth of 1?m from each of five sampling sites with a spatial gradient of environmental stress from June 2007 to May 2008. A range of physico-chemical variables were measured synchronously for comparison with biotic parameters.Results
The spatial body-size patterns of ciliated zooplankton represented significant differences among the five sites, and were significantly correlated with the changes of physico-chemical parameters, especially salinity, dissolved oxygen and nutrients. Two paired indices, the average body-size distinctness (AvBSD) and the variation in body-size distinctness (VarBSD), were proposed based on the trait resemblances among ciliate species in body-size pattern. The paired measures showed a clear decreasing trend of departure from the expected body-size spectra in response to water quality status.Conclusion
These results suggest that the body-size pattern of ciliated zooplankton might be used as a potential indicator of marine water quality. 相似文献550.
Huang C Chen X Liu T Yang Z Xiao Y Zeng G Sun X 《Environmental science and pollution research international》2012,19(5):1416-1421