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   174篇
  免费   1篇
  国内免费   4篇
安全科学   1篇
废物处理   19篇
环保管理   11篇
综合类   14篇
基础理论   24篇
环境理论   1篇
污染及防治   72篇
评价与监测   25篇
社会与环境   12篇
  2023年   9篇
  2022年   23篇
  2021年   16篇
  2020年   9篇
  2019年   4篇
  2018年   13篇
  2017年   13篇
  2016年   15篇
  2015年   5篇
  2014年   3篇
  2013年   15篇
  2012年   9篇
  2011年   8篇
  2010年   7篇
  2009年   2篇
  2008年   3篇
  2007年   4篇
  2006年   1篇
  2005年   4篇
  2004年   2篇
  2003年   1篇
  2002年   4篇
  2001年   1篇
  1995年   1篇
  1985年   1篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
  1961年   1篇
  1959年   2篇
排序方式: 共有179条查询结果,搜索用时 15 毫秒
101.
Modelling-based studies to assess the extent and magnitude of ozone (O3) risk to agriculture in Asia suggest that yield losses of 5–20% for important crops may be common in areas experiencing elevated O3 concentrations. These assessments have relied on European and North American dose–response relationships and hence assumed an equivalent Asian crop response to O3 for local cultivars, pollutant conditions and climate. To test this assumption we collated comparable dose–response data derived from fumigation, filtration and EDU experiments conducted in Asia on wheat, rice and leguminous crop species. These data are pooled and compared with equivalent North American dose–response relationships. The Asian data show that at ambient O3 concentrations found at the study sites (which vary between ~35–75 ppb 4–8 h growing season mean), yield losses for wheat, rice and legumes range between 5–48, 3–47 and 10–65%, respectively. The results indicate that Asian grown wheat and rice cultivars are more sensitive to O3 than the North American dose–response relationships would suggest. For legumes the scatter in the data makes it difficult to reach any equivalent conclusion in relative sensitivities. As such, existing modelling-based risk assessments may have substantially underestimated the scale of the problem in Asia through use of North American derived dose–response relationships.  相似文献   
102.
People's perception of crime and incivilities vary considerably depending on their attitudes towards environmental conditions. This paper investigated the hypothesised relationships between Crime Prevention Through Environmental Design (CPTED), victimisation and fear of crime. The checklist was administered by using on-site observation to measure the CPTED construct followed by a self-administered questionnaire to explore the residents' perceptions of victimisation and fear of crime in their area of residency. In all, 164 respondents from a selected group of residents were involved in this study. The structural equation modelling technique was employed and the results indicate that CPTED is negatively related to victimisation. The model also shows that there is a significant positive direct influence of victimisation on fear of crime. However, no direct significant relationship was found between CPTED and fear of crime, but a negative indirect relationship between CPTED and fear of crime was observed through victimisation.  相似文献   
103.
Heavy metal contamination of agricultural soils has received great concern due to potential risk to human health. Cadmium and Pb are largely released from abandoned or closed mines in Korea, resulting in soil contamination. The objective of this study was to evaluate the effects of eggshell waste in combination with the conventional nitrogen, phosphorous, and potassium fertilizer (also known as NPK fertilizer) or the rapeseed residue on immobilization of Cd and Pb in the rice paddy soil. Cadmium and Pb extractabilities were tested using two methods of (1) the toxicity characteristics leaching procedure (TCLP) and (2) the 0.1 M HCl extraction. With 5 % eggshell addition, the values of soil pH were increased from 6.33 and 6.51 to 8.15 and 8.04 in combination with NPK fertilizer and rapeseed residue, respectively, compared to no eggshell addition. The increase in soil pH may contribute to heavy metal immobilization by altering heavy metals into more stable in soils. Concentrations of TCLP-extracted Cd and Pb were reduced by up to 67.9 and 93.2 % by addition of 5 % eggshell compared to control. For 0.1 M HCl extraction method, the concentration of 0.1 M HCl-Cd in soils treated with NPK fertilizer and rapeseed residue was significantly reduced by up to 34.01 and 46.1 %, respectively, with 5 % eggshell addition compared to control. A decrease in acid phosphatase activity and an increase in alkaline phosphatase activity at high soil pH were also observed. Combined application of eggshell waste and rapeseed residue can be cost-effective and beneficial way to remediate the soil contaminated with heavy metals.  相似文献   
104.
Strongyloidiasis presents a major health hazard when reusing wastewater. Albendazol with a concentration of 4 mg/l, a contact time of 45 min, pH 1.2 and pH 10.2, killed the larva. The larva was also killed with a 0.03% concentration of iodine and a detention time of 30 min or a 0.04% concentration of iodine and a contact time of 10 min. The required detention time to inactivate larva in water was found to be 17 days. The minimum revealed residual chlorine to kill the larvae was 4 mg/l with 120 min of detention time, and a minimum contact time was found to be 80 min with a residual of 23 mg/l. Many methods are available to inactivate the Strongyloides stercoralis, which could be acids, alkaline chemicals, larvicidal chemicals, super chlorination, or just detention time. The best method must be determined according to the prevailing specific environmental site and the feasibility of the selected method(s).  相似文献   
105.
A study on source apportionment of indoor dust and particulate matter (PM10) composition was conducted in a university building by using chemometrics. The objective of this study was to investigate the potential sources of selected heavy metals and ionic species in PM10 and indoor dust. PM10 samples were collected using a low-volume sampler (LVS) and indoor dust was collected using a soft brush. Inductively coupled plasma spectrometry (ICP-MS) was used to determine the concentration of heavy metals, while the concentration of cations and anions was determined by atomic absorption spectrometer (AAS) and ion chromatography (IC), respectively. The concentration of PM10 recorded in the building throughout the sampling period ranged from 20 ± 10 μgm?3 to 80 ± 33 μgm?3. The composition of heavy metals in PM10 and indoor dust were dominated by zinc (Zn), followed by lead (Pb), copper (Cu), and cadmium (Cd). Principle component analysis (PCA) and multiple linear regression (MLR) showed that the main sources of pollutants in PM10 came from indoor renovations (73.83%), vehicle emissions (16.38%), earth crust sources (9.68%), and other outdoor sources (0.11%). For indoor dust, the pollutant source was mainly earth crust. This study suggests that chemometrics can be used for forensic investigation to determine the possible sources of indoor contaminants within a public building.  相似文献   
106.
Commercially known Ahmer oxide paints are prepared from raw material mainly composed of red iron oxides (hematite) and iron oxyhydroxides. The raw material used in manufacturing of Ahmer oxide comes from some localities in southwest Sinai such as Abu Thor, Allouga, and El lehian. The adsorption of uranium and other radioelements on iron oxides could make the raw material (red iron oxides) and their products environmentally hazardous. The studied samples were subjected to radiometric analysis using NaI (Tl) gamma-ray spectrometer. The average activity concentration of U, Th, Ra, and K are 108.7, 458.8, 88.8, and 627.5?Bq?kg?1, respectively in raw material and 136.4, 14.6, 58.3, and 95.9?Bq?kg?1 in Ahmer oxide. High values of activity concentrations of 238U, 226Ra, and 40K were recorded in Allouga and El lehian raw material. High radioactivities of Allouga and El lehian raw material are mainly attributed to the presence of torbernite, zircon, and monazite, in addition to adsorbed elemental uranium in Ahmer oxide. absorbed dose rate (D), annual effective dose equivalent, radium equivalent activity (Raeq), external hazard index (Hex), and internal hazard index (Hin), as well as representative gamma index (Iγ) were determined from the activity concentrations of 226Ra, 232Th, and 40K. Some of the studied samples do not satisfy the universal standards.  相似文献   
107.
Environmental Chemistry Letters - The demand for nanoparticles has been increasing rapidly in recent years due to their unique properties of interest for a wide range of applications. Several...  相似文献   
108.
Environmental Science and Pollution Research - Exposure to light at night, pineal gland impairment, and the environmental pollutant trichloroethylene (TCE) have serious implications for health and...  相似文献   
109.
Environmental Science and Pollution Research - Bivalves are considered a main consumed matrix for coastal communities worldwide and classified as hyperaccumulators of pollutants. The present study...  相似文献   
110.
Environmental Science and Pollution Research - One of the major challenges faced by human society is the freshwater crisis and shortage of conventional energy. Solar still is considered as one of...  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