全文获取类型
收费全文 | 999篇 |
免费 | 40篇 |
国内免费 | 474篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 75篇 |
环保管理 | 71篇 |
综合类 | 501篇 |
基础理论 | 209篇 |
环境理论 | 1篇 |
污染及防治 | 487篇 |
评价与监测 | 53篇 |
社会与环境 | 22篇 |
灾害及防治 | 36篇 |
出版年
2023年 | 20篇 |
2022年 | 43篇 |
2021年 | 40篇 |
2020年 | 34篇 |
2019年 | 31篇 |
2018年 | 35篇 |
2017年 | 38篇 |
2016年 | 69篇 |
2015年 | 75篇 |
2014年 | 93篇 |
2013年 | 96篇 |
2012年 | 83篇 |
2011年 | 94篇 |
2010年 | 75篇 |
2009年 | 76篇 |
2008年 | 98篇 |
2007年 | 49篇 |
2006年 | 59篇 |
2005年 | 35篇 |
2004年 | 35篇 |
2003年 | 44篇 |
2002年 | 51篇 |
2001年 | 30篇 |
2000年 | 31篇 |
1999年 | 29篇 |
1998年 | 36篇 |
1997年 | 23篇 |
1996年 | 30篇 |
1995年 | 19篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1983年 | 3篇 |
排序方式: 共有1513条查询结果,搜索用时 0 毫秒
841.
842.
Effect of organic wastes on the plant-microbe remediation for removal of aged PAHs in soils 总被引:1,自引:0,他引:1
The effectiveness of in-situ bioremediation of polycyclic aromatic hydrocarbons (PAHs) may be inhibited by low nutrients and organic carbon. To evaluate the effect of organic wastes on the PAHs removal efficiency of a plant-microbe remediation system, contaminated agricultural soils were amended with different dosages of sewage sludge (SS) and cattle manure (CM) in the presence of alfalfa (Medicago sativa L.) and PAHs-degraders (Bacillus sp. and Flavobacterium sp.). The results indicated that the alfalfa mean biomasses varied from 0.56 to 2.23 g/pot in root dry weight and from 1.80 to 4.88 g/pot in shoot dry weight. Low dose amendments, with rates of SS at 0.1% and CM at 1%, had prominent effects on plant growth and soil PAHs degradation. After 60-day incubation, compared with about 5.6% in the control, 25.8% PAHs removal was observed for treatments in the presence of alfalfa and PAHs-degraders; furthermore, when amended with different dosages of SS and CM, the removed PAHs from soils increased by 35.5%-44.9% and 25.5%-42.3%, respectively. In particular, the degradation of high-molecular-weight PAHs was up to 42.4%. Dehydrogenase activities (DH) ranged between 0.41 and 1.83 μupg triphenylformazan/(g dry soil. hr) and the numbers of PAHs-degrading microbes (PDM) ranged from 1.14× 106 to 16.6× 106 most-probable-number/g dry soil. Further investigation of the underlying microbial mechanism revealed that both DH and PDM were stimulated by the addition of organic wastes and significantly correlated with the removal ratio of PAHs. In conclusion, the effect of organic waste application on soil PAHs removal to a great extent is dependent on the interactional effect of nutrients and dissolved organic matter in organic waste and soil microorganisms. 相似文献
843.
曾向宏 《安全.健康和环境》2013,13(8):17-19
分析了承包商HSE监督管理方面存在的不足,提出第二方审核作为监督管理的延伸和补充,在促进承包商自主管理、自我提升和培养长期合作承包商的作用和意义,指出针对不同类型承包商开展第二方审核的实施重点。 相似文献
844.
快速生物降解性试验在新化学物质的生态毒理测试中占据重要地位,其测试数据的可靠性直接影响后续的测试策略和物质的申报登记、以及新化学物质进入环境后的风险管理。为研究OECD 301系列试验(301B、301D和301F)的质量,选用本机构近5年来积累的标准化物质苯甲酸钠14 d快速生物降解率数据,首次采用稳健统计技术,以稳健总计统计量的Z比分数作为评价指标,对各试验数据和试验系统的质量开展评估。结果显示,当301B、301D和301F试验的苯甲酸钠降解率分别在63.8%~88.0%、63.4%~89.2%和66.0%~99.8%范围内时,表明测试结果满意,该批次试验数据质量良好;若苯甲酸钠降解率不在此范围,则表明测试结果可能存在问题,甚至得到的可能是错误数据,需要进一步验证。据此提出了对实际测试工作具有指导意义的质量分析对照表,以期为测试机构开展新化学物质快速生物降解性试验时的质量分析提供参考。 相似文献
845.
采用标准指数法、综合评价法和灰色关联分析法对西藏地区4个典型垃圾填埋场周边地表水环境质量进行分析和评价。结果表明:各填埋场各评价因子均满足《地表水环境质量标准》(GB 3838—2002)Ⅲ类标准;各填埋场临近地表水环境综合水质均呈现上游监测点优于下游监测点;综合水质现状为尚清洁—清洁;灰色关联分析法评价结果为工布江达县生活垃圾填埋场下游监测点水质为Ⅱ类,其他填埋场各监测点水质均为Ⅰ类。各填埋场临近地表水水质现状满足其水域功能区要求,受填埋场污染环境影响较小。 相似文献
846.
Optimization of H2O2 dosage in microwave-H2O2 process for sludge pretreatment with uniform design method 总被引:6,自引:0,他引:6
Qingcong Xiao Hong Yan Yuansong Wei Yawei Wang Fangang Zeng Xiang Zheng 《环境科学学报(英文版)》2012,24(12):2060-2067
A microwave-H2O2 process for sludge pretreatment exhibited high efficiencies of releasing organics, nitrogen, and phosphorus, but large quantities of H2O2 residues were detected. A uniform design method was thus employed in this study to further optimize H2O2 dosage by investigating effects of pH and H2O2 dosage on the amount of H2O2 residue and releases of organics, nitrogen, and phosphorus. A regression model was established with pH and H2O2 dosage as the independent variables, and H2O2 residue and releases of organics, nitrogen, and phosphorus as the dependent variables. In the optimized microwave-H2O2 process, the pH value of the sludge was firstly adjusted to 11.0, then the sludge was heated to 80℃ and H2O2 was dosed at a H2O2:mixed liquor suspended solids (MLSS) ratio of 0.2, and the sludge was finally heated to 100℃ by microwave irradiation. Compared to the microwave-H2O2 process without optimization, the H2O2 dosage and the utilization rate of H2O2 in the optimized microwave-H2O2 process were reduced by 80% and greatly improved by 3.87 times, respectively, when the H2O2:MLSS dosage ratio was decreased from 1.0 to 0.2, resulting in nearly the same release rate of soluble chemical oxygen demand in the microwave-H2O2 process without optimization at H2O2:MLSS ratio of 0.5. 相似文献
847.
848.
Huaying Li Yunguo Liu Guangming Zeng Lu Zhou Xin Wang Yaqin Wang Chunlin Wang Xinjiang Hu Weihua Xu 《环境科学学报(英文版)》2014,26(12):2508-2516
Boehmeria nivea(L.) Gaud. is a potential candidate for the remediation of Cd contaminated sites. The present investigation aims to explore Cd tolerance threshold and to quickly identify the role of exogenous organic acids in Cd uptake and abiotic metal stress damage.Elevated Cd levels(0–10 mg/L) resulted in an obvious rise in Cd accumulation, ranging from268.0 to 374.4 in root and 25.2 to 41.2 mg/kg dry weight in shoot, respectively. Citric acid at1.5 mmol/L significantly facilitated Cd uptake by 26.7% in root and by 1-fold in shoot,respectively. Cd translocation efficiency from root to shoot was improved by a maximum of66.4% under 3 mmol/L of oxalic acid. Citric acid exhibited more prominent mitigating effect than oxalic acid due to its stronger ligand affinity for chelating with metal and avoiding the toxicity injury of free Cd ions more efficiently. The present work provides a potential strategy for efficient Cd remediation with B. nivea. 相似文献
849.
本文研究了6种化学农药对植物根际和根表固氮微生物固氮螺菌(A.brasilense)的固氮酶和吸氢酶活性的影响。实验采用半固体培养基并分别加入不同浓度的农药,还设有加苹果酸钠和不加苹果酸钠两种处理。结果表明,农药对固氮螺菌两种酶活性的作用可分为三种类型:具明显的抑制作用(如六六六和二氯苯醚菊酯)、具刺激作用(如水胺硫磷和灭线磷)和加苹果酸钠时有刺激作用(如速灭杀丁和溴氰菊酯)。 相似文献
850.
生物脱氮除磷活性污泥系统复合模拟方法 总被引:1,自引:0,他引:1
为避免繁琐的参数校核工作,提出了活性污泥2 d号模型(ASM2d)和人工神经网络(ANNs)相结合的复合模拟方法。考察了复合方法在某污水处理厂生物脱氮除磷工艺中的应用情况。研究表明,ANNs能够准确地模拟出水实测值与未经校核的ASM2d机理模型的估计值之间的差值。利用Levenberg-Marquardt算法,对出水氨氮、总氮和总磷分别建立网络结构为5-12-1、5-8-1和5-8-1的ANNs子模型,将这些子模型输出同ASM2d机理模型输出相加便得到复合模型输出。复合模型估计值对前10.4 d(ANNs子模型训练数据时段)出水氨氮、总氮和总磷浓度的拟合平均绝对百分比误差分别为0.267、0.055和0.048;其对后2.6 d(ANNs子模型测试数据时段)出水氨氮、总氮和总磷浓度的预测平均绝对百分比误差分别为0.332、0.083和0.069。均方根误差、平均绝对误差等评价指标也表明复合模型能够给出合理的模拟结果。 相似文献