全文获取类型
收费全文 | 1419篇 |
免费 | 74篇 |
国内免费 | 523篇 |
专业分类
安全科学 | 93篇 |
废物处理 | 87篇 |
环保管理 | 87篇 |
综合类 | 821篇 |
基础理论 | 253篇 |
污染及防治 | 540篇 |
评价与监测 | 48篇 |
社会与环境 | 47篇 |
灾害及防治 | 40篇 |
出版年
2023年 | 35篇 |
2022年 | 93篇 |
2021年 | 96篇 |
2020年 | 48篇 |
2019年 | 51篇 |
2018年 | 53篇 |
2017年 | 72篇 |
2016年 | 66篇 |
2015年 | 72篇 |
2014年 | 121篇 |
2013年 | 123篇 |
2012年 | 111篇 |
2011年 | 133篇 |
2010年 | 84篇 |
2009年 | 99篇 |
2008年 | 108篇 |
2007年 | 92篇 |
2006年 | 60篇 |
2005年 | 47篇 |
2004年 | 47篇 |
2003年 | 51篇 |
2002年 | 27篇 |
2001年 | 40篇 |
2000年 | 46篇 |
1999年 | 37篇 |
1998年 | 37篇 |
1997年 | 24篇 |
1996年 | 26篇 |
1995年 | 21篇 |
1994年 | 16篇 |
1993年 | 17篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1990年 | 15篇 |
1989年 | 6篇 |
1988年 | 10篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有2016条查询结果,搜索用时 547 毫秒
851.
852.
地面监测得到的近地面细颗粒物PM_(2.5)浓度较为精确,但数据覆盖范围相对较小,卫星遥感反演的气溶胶光学厚度(AOD)数据可以反映污染物浓度分布,具有范围大且速度快的特点,因此,大多数学者通过建立PM_(2.5)-AOD模型来实现卫星遥感监测PM_(2.5)浓度,并通过引入气象要素来优化模型.然而,气象要素的选择与引入往往对模型的精度有较大的影响,如何有效地选择对PM_(2.5)浓度影响较大的气象要素一直是PM_(2.5)-AOD模型中的关键问题.因此,本文基于华东地区2014—2015年的MODIS AOD和地面监测站的PM_(2.5)浓度数据,结合再分析气象资料,利用多元逐步线性回归方法建立PM_(2.5)-AOD模型,从由特定时刻、高度上的气象要素与随时间、高度变化的气象要素组成的气象要素集中,筛选出对因变量PM_(2.5)浓度有显著影响的关键气象要素.结果表明:在地域与季节双重尺度下的PM_(2.5)-AOD模型精度更高;相较于特定时刻高度的气象要素,随时间和高度变化的气象要素对PM_(2.5)-AOD模型的影响更为显著;在地域与季节双重尺度下,1000~850 hPa经向风速差、世界时0:00—6:00近地面温度差、850~600 hPa温度差、6:00边界层高度、12:00—18:00近地面压强差、1000~850 hPa温度差对模型影响较大,但应依据不同季节和不同地区的具体影响程度作为选择标准. 相似文献
853.
Zhaojun Wen Xinping Duan Menglin Hu Yanning Cao Linmin Ye Lilong Jiang Youzhu Yuan 《环境科学学报(英文版)》2018,30(2):122-129
In this study, the effects of copper(Cu) additive on the catalytic performance of Ag/SBA-15 in complete soot combustion were investigated. The soot combustion performance of bimetallic Ag–Cu/SBA-15 catalysts was higher than that of monometallic Ag and Cu catalysts. The optimum catalytic performance was acquired with the 5 Ag_1-Cu_(0.1)/SBA-15 catalyst, on which the soot combustion starts at T_(ig)= 225°C with a T_(50)= 285°C. The temperature for 50% of soot combustion was lower than that of conventional Ag-based catalysts to more than 50°C(Aneggi et al., 2009). Physicochemical characterizations of the catalysts indicated that addition of Cu into Ag could form smaller bimetallic Ag–Cu nanolloy particles, downsizing the mean particle size from 3.7 nm in monometallic catalyst to 2.6 nm in bimetallic Ag–Cu catalyst. Further experiments revealed that Ag and Cu species elicited synergistic effects, subsequently increasing the content of surface active oxygen species. As a result, the structure modifications of Ag by the addition of Cu strongly intensified the catalytic performance. 相似文献
854.
Wenhui Li Haidi Liu Shuangde Li Weiman Li Yunfa Chen Jiajia Gao Yaqun Cao 《环境科学学报(英文版)》2018,30(2):190-196
A co-current flow rotating packed bed was applied to remove volatile organic compounds(VOCs) by sodium hypochlorite(Na Cl O) and surfactant(sodium dodecyl benzene sulfonate,SDBS) from air stream. Xylene was used as a model VOC herein. The effect of p H,concentration of Na Cl O and SDBS solution, liquid flow rate, gas flow rate and rotational speed on xylene removal efficiency and overall mass transfer coefficient(KGa) were discussed. Then, a correlation for KGa of the co-current rotating packed bed was proposed by fitting the experimental data of KGa and independent variables of liquid/gas ratio,rotational speed, p H, Na Cl O concentration and treatment time, which was in good agreement with the experimental data(the deviation ≤± 30%). 相似文献
855.
土壤作物系统镉污染及其防治研究 总被引:10,自引:0,他引:10
选择我国北方主要粮食作物冬小麦和夏谷进行盆栽试验,研究了土壤镉污染对作物生长发育和产量的影响及泥炭、羊粪两种不同类型的有机肥缓减土壤镉污染危害的作用;分析了镉在两种作物不同器官中的迁移效率和累积规律;认为施加有机肥是缓减土壤镉污染危害的有效措施,且施羊粪的效果比施泥炭好。 相似文献
856.
857.
芳香族醛酮化合物溶解度和分配系数的测定与估算 总被引:9,自引:0,他引:9
本文测定了15种芳香族醛酮化合物的溶解度和正辛醇-水分配系数,研究了水溶解度及分配系数与分子连接性能指数的相关性。结果表明,溶解度和分配系数之间以及与分子连接性指数呈较好的线性关系。 相似文献
858.
光子相关光谱(PCS)在无机高分子絮凝剂形态表征中的应用 总被引:6,自引:1,他引:6
本文运用现代先进的微粒检测手段光子相关光谱对常见的两类无机高分子絮凝剂的形态进行了表征。实验结果表明:在所测聚合氯化铁溶液中,体系呈较为单一的集中分布,由平移扩散系数计算得到平均有效直径在5-11nm左右。在所测聚合氯化铝溶液中,主要为双峰分布,熟化后样品约为2-5nm的小颗粒与数十nm以上分布较宽的聚集体,另外,本文对光子相关光谱在形态表征中的优缺点及其它应用的可能性也作了一定的论述。 相似文献
859.
Field studies on 32P movement and P leaching from flooded paddy soils in the region of Taihu Lake, China 总被引:5,自引:0,他引:5
Xie XJ Ran W Shen QR Yang CY Yang JJ Cao ZH 《Environmental geochemistry and health》2004,26(2-3):237-243
Field experiments were done in two sites, Yixing and Changshu, Jiangsu province, China, to study P movement and leaching in flooded paddy soils. P movement in soil was investigated by using the KH2 32PO4 tracker method, and the amount of P leached from the soil layer in different depths was estimated by measuring P concentrations in the soil solution and saturated hydraulic conductivities in field. Determination was done about one month after P application. There was 46% and 42% of total 32P retained in the 0-5cm layer of soil in the Yixing site and in the Changshu site respectively. The 32P retained in the 25-30 cm layer was only about 1-2% of the total 32P added. Furthermore, 8.01% of 32P in the soil of Yixing site and 16.8% of 32P in the soil of Changshu site was lost from the layer 0-30 cm soil. The seasonal amounts of P leached from the top soil layer and from bottom layer are about 4.5-5.8% and 1.6-2.1% of the total P application, respectively. Changes of total P concentrations in soil solutions during rice growth showed that the fertilizer P applied before flooding of the paddy fields suffered a flash leaching loss and a slow leaching loss. We concluded that the fertilizer P could quickly move in the flooded paddy rice field and parts of it can enter into surface water and ground water. Unless the P application is well managed the risk of P loss and consequently environmental pollution exist. 相似文献
860.
The photocatalytic degradation of gaseous trichloroethylene (TCE) without water has been studied. The degradation products were determined to be CO2, HCl and Cl2, and the reaction stoichiometry, was described as . The degradation rate was found to be linear with 0.16 power of the illumination intensity. When the TCE concentration was low (1014 mol L−1 or a little more), its degradation rate model could be considered as first order kinetics. A mechanism of valence band hole oxidation was proposed. 相似文献