首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1406篇
  免费   9篇
  国内免费   34篇
安全科学   15篇
废物处理   81篇
环保管理   185篇
综合类   131篇
基础理论   251篇
污染及防治   469篇
评价与监测   238篇
社会与环境   75篇
灾害及防治   4篇
  2023年   35篇
  2022年   84篇
  2021年   68篇
  2020年   18篇
  2019年   31篇
  2018年   52篇
  2017年   39篇
  2016年   64篇
  2015年   32篇
  2014年   60篇
  2013年   178篇
  2012年   65篇
  2011年   89篇
  2010年   61篇
  2009年   59篇
  2008年   88篇
  2007年   52篇
  2006年   55篇
  2005年   40篇
  2004年   38篇
  2003年   33篇
  2002年   23篇
  2001年   19篇
  2000年   12篇
  1999年   11篇
  1998年   6篇
  1997年   8篇
  1996年   8篇
  1993年   6篇
  1992年   9篇
  1991年   8篇
  1990年   3篇
  1989年   5篇
  1988年   3篇
  1987年   10篇
  1986年   5篇
  1985年   4篇
  1983年   3篇
  1982年   5篇
  1980年   3篇
  1978年   4篇
  1976年   6篇
  1975年   4篇
  1972年   3篇
  1969年   5篇
  1968年   4篇
  1966年   3篇
  1959年   3篇
  1957年   4篇
  1956年   3篇
排序方式: 共有1449条查询结果,搜索用时 15 毫秒
141.
Incineration of cellulose waste filter from acrylic industry showed the presence of 13–16 polycyclic aromatic hydrocarbons (PAHs) from the list of 16 priority pollutants with an airflow rate of 1, 2, 3, and 4 L min???1 in laboratory scale quartz tube vertical incinerator at 700–1,000°C at an interval of 100°C. The amount of total 16 PAHs increases with the increase in temperature with airflow rate of 1 L min???1 and was found to be 9.4 times at 1,000°C than at 700°C. Studies at 800–1,000°C showed the decrease in total 16 PAHs with increase in airflow rate from 1 to 2 L min???1. The amount of total 16 PAHs increases at 700, 800, and 1,000°C with increase in airflow rate from 2–4 L min???1. At 900°C, amount of 16 PAHs decreases with increase in flow rate from 1 to 3 and increases at 4 L min???1. The lesser amount of 2A PAHs was found at 700–900°C with airflow rates of 1–3 L min???1, while less amount of 2B PAHs was found at 700°C and 800°C (with airflow rate of 1–2 L min???1), at 900°C (with airflow rate of 1–3 L min???1) and at 1,000°C (with airflow rate of 3 L min???1). However, the sum total of 2A and 2B PAHs were found to be less at 700–900°C with airflow rate of 1–2 L min???1.  相似文献   
142.
143.
144.
145.
Abstract: A practical methodology is proposed to estimate the three‐dimensional variability of soil moisture based on a stochastic transfer function model, which is an approximation of the Richard’s equation. Satellite, radar and in situ observations are the major sources of information to develop a model that represents the dynamic water content in the soil. The soil‐moisture observations were collected from 17 stations located in Puerto Rico (PR), and a sequential quadratic programming algorithm was used to estimate the parameters of the transfer function (TF) at each station. Soil texture information, terrain elevation, vegetation index, surface temperature, and accumulated rainfall for every grid cell were input into a self‐organized artificial neural network to identify similarities on terrain spatial variability and to determine the TF that best resembles the properties of a particular grid point. Soil moisture observed at 20 cm depth, soil texture, and cumulative rainfall were also used to train a feedforward artificial neural network to estimate soil moisture at 5, 10, 50, and 100 cm depth. A validation procedure was implemented to measure the horizontal and vertical estimation accuracy of soil moisture. Validation results from spatial and temporal variation of volumetric water content (vwc) showed that the proposed algorithm estimated soil moisture with a root mean squared error (RMSE) of 2.31% vwc, and the vertical profile shows a RMSE of 2.50% vwc. The algorithm estimates soil moisture in an hourly basis at 1 km spatial resolution, and up to 1 m depth, and was successfully applied under PR climate conditions.  相似文献   
146.
147.
This work was to study composition characteristics and the subsequent effect on the lead (Pb) binding properties of dissolved organic matter (DOM) derived from seaweed-based (SWOF) and chicken manure organic fertilizers (CMOF) during a one-year field incubation experiment using the excitation-emission matrix-parallel factor (EEM-PARAFAC) and two-dimensional correlation spectroscopy (2DCOS) analysis. Results showed that high aromatic and hydrophobic fluorescent substances were enriched in CMOF-derived DOM and SWOF-derived DOM and enhanced over time. And phenolic groups in the fulvic-like substances for SWOF-derived DOM and carboxyl groups in the humic-like substances for CMOF-derived DOM had the fastest responses over time, respectively. Moreover, both non-fluorescent polysaccharides and fluorescent humic-like substances or fulvic-like substances with aromatic (C=C) groups first participated in the binding process of Pb to SWOF-derived DOM on day 0 and 180 during the lead binding process. In contrast, humic-like substances associated with aromatic (C=C) and phenolic groups gave a faster response to Pb binding on day 360. Regarding CMOF-derived DOM, the fulvic-like substances associated with aromatic (C=C) and carboxylic groups displayed a faster response to Pb ions on day 0. Nonetheless, polysaccharides and humic-like associated with phenolic groups had a faster response on days 180 and 360. It is noteworthy that the polysaccharides, which participated in Pb binding to CMOF-derived DOM, posed a higher risk of Pb in the environment after 360 days. Therefore, these findings gave new insights into the long-term applications of commercial organic fertilizers for the amendment of soil.  相似文献   
148.
149.

Background, aim, and scope  

Lindane, technically 1, 2, 3, 4, 5, 6-hexachlorocyclohexane (γ- HCH), is the most commonly detected organochlorine pesticide from diverse environmental compartments. Currently, India is the largest consumer and producer of lindane in the world. The production of lindane results in the generation of large quantities of waste HCH isomers (mainly α-, β- and δ-). All these isomers are toxic and have a long-range environmental transport potential. The aim of this study was to monitor the seasonal variation of HCH isomers in an open soil–plant–rhizospheric soil system of a contaminated industrial area. For this, selected plant species and their rhizospheric soil (soil samples collected at a depth range of 0–45 cm near to the root system) and open soil samples (soil samples collected (0–30 cm depth) from 1–1.5 m away from the plant root system) were collected for 2 years (two summer seasons and two winter seasons).  相似文献   
150.
Binding affinity of metanil yellow and its breakdown product p‐aminodiphenylamine to serum proteins has been studied employing chromatographic separation on Sephadex G‐200 and by paper and polyacrylamide gel electrophoresis. Metanil yellow has more affinity towards albumin than to globulins. The complexing is presumably through electrostatic forces. p‐Aminodiphenylamine on the other hand, preferably binds to globulin fractions of serum protein. However, a stable binding with BSA alone was also observed. The binding was quite stable and was accompanied by a shift in absorbance from 430 nm to 500 nm. Aspartic acid moiety of protein was found to be one of the units involved in the binding of p‐ADPA to proteins.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号