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   1029篇
  免费   11篇
  国内免费   35篇
安全科学   414篇
废物处理   8篇
环保管理   142篇
综合类   188篇
基础理论   81篇
污染及防治   94篇
评价与监测   54篇
社会与环境   35篇
灾害及防治   59篇
  2023年   16篇
  2022年   12篇
  2021年   49篇
  2020年   54篇
  2019年   23篇
  2018年   11篇
  2017年   28篇
  2016年   41篇
  2015年   50篇
  2014年   45篇
  2013年   69篇
  2012年   43篇
  2011年   86篇
  2010年   20篇
  2009年   74篇
  2008年   66篇
  2007年   54篇
  2006年   32篇
  2005年   39篇
  2004年   35篇
  2003年   39篇
  2002年   26篇
  2001年   18篇
  2000年   15篇
  1999年   19篇
  1998年   14篇
  1997年   13篇
  1996年   12篇
  1995年   10篇
  1994年   8篇
  1993年   16篇
  1992年   8篇
  1991年   2篇
  1990年   4篇
  1989年   3篇
  1988年   1篇
  1987年   5篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1981年   7篇
  1980年   1篇
排序方式: 共有1075条查询结果,搜索用时 234 毫秒
191.
Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10?10, 3.49 × 10?9 and 1.41 × 10?8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10?6), indicating acceptable health risk of nPAHs and oPAHs.  相似文献   
192.
Problem: Pedestrian injury is a major hazard to the health of children in most developed countries, including Australia. In a previous study it was found that parental road risk perception is a significant factor associated with their modeling of safe behavior as pedestrians. This study aimed to investigate factors that affect parental road risk perception. Method: This cross-sectional population-based randomized telephone survey aimed to study factors associated with risk perception on pedestrian road safety among parents with young children aged 4–12 years. Results: Five factors were found to be significantly associated with parental risk perception. They included age of child, sex of parent, employment of parent, living environment, and previous injury experience. The results suggested that the age of the child contributed greatest to the variance explained by the regression model. However, other factors remained significant even after adjusting for each other. Discussion: Results were discussed in light of the design and development of childhood pedestrian road safety campaigns. Impact on industry: Parental risk perceptions determine their safe road modeling behavior. In this study, significant factors that affect parental road risk perception have been identified. The information obtained can be used in the design of road safety programs that aim at changing the road risk perception of parents.  相似文献   
193.
危险辨识方法的研究   总被引:15,自引:7,他引:8  
介绍了一种新的危险辨识方法 ,应用该方法可以系统地发现潜在的事故序列、事故的起始事件以及相应控制系统的薄弱环节 ,为进一步的风险分析奠定基础  相似文献   
194.
The objective of this study was to characterize recovered soil fines from construction and demolition (C&D) waste recycling facilities for trace organic pollutants. Over a period of 18 months, five sampling trips were made to 14 C&D waste recycling facilities in Florida. Screened soil fines were collected from older stockpiles and newly generated piles at the sites. The samples were analyzed for the total concentration (mg/kg) of a series of volatile organic compound (VOCs) and semi-volatile organic compounds (semi-VOCs). The synthetic precipitation leaching procedure (SPLP) test was also performed to evaluate the leachability of the trace organic chemicals. During the total analysis only a few volatile organic compounds were commonly found in the samples (trichlorofluoromethane, toluene, 4-isopropyltoluene, trimethylbenzene, xylenes, and methylene chloride). A total of nine VOCs were detected in the leaching test. Toluene showed the highest leachability among the compounds (61.3-92.0%), while trichlorofluoromethane, the most commonly detected compound from both the total and leaching tests, resulted in the lowest leachability (1.4-39.9%). For the semi-VOC analysis, three base-neutral semi-VOC compounds (bis(2-ethylhexyl)phthalate, butyl benzyl phthalate, and di-n-butyl phthalate) and several PAHs (acenaphthene, pyrene, fluoranthene, and phenanthrene) were commonly detected in C&D fines samples. These compounds also leached during the SPLP leaching test (0.1-25%). No acid extractable compounds, pesticides, or PCBs were detected. The results of this study were further investigated to assess risk from land applied recovered soil fines by comparing total and leaching concentrations of recovered soil fines samples to risk-based standards. The results of this indicate that the organic chemicals in recovered soil fines from C&D debris recycling facilities were not of a major concern in terms of human risk and leaching risk to groundwater under reuse and contact scenarios.  相似文献   
195.
Animals balance feeding and anti-predator behaviors at various temporal scales. When risk is infrequent or brief, prey can postpone feeding in the short term and temporally allocate feeding behavior to less risky periods. If risk is frequent or lengthy, however, prey must eventually resume feeding to avoid fitness consequences. Species may exhibit different behavioral strategies, depending on the fitness tradeoffs that exist in their environment or across their life histories. North Pacific flatfishes that share juvenile rearing habitat exhibit a variety of responses to predation risk, but their response to risk frequency has not been examined. We observed the feeding and anti-predator behaviors of young-of-the-year English sole (Parophrys vetulus), northern rock sole (Lepidopsetta polyxystra), and Pacific halibut (Hippoglossus stenolepis)—three species that exhibit divergent anti-predator strategies—following exposure to three levels of predation risk: no risk, infrequent (two exposures/day), and frequent (five exposures/day). The English sole responded to the frequent risk treatment with higher feeding rates than during infrequent risk, following a pattern of behavioral response that is predicted by the risk allocation hypothesis; rock sole and halibut did not follow the predicted pattern, but this may be due to the limited range of treatments. Our observations of unique anti-predator strategies, along with differences in foraging and species-specific ecologies, suggest divergent trajectories of risk allocation for the three species.  相似文献   
196.
Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the often-limited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides.  相似文献   
197.
Surveys of water recreational activities were conducted in the Peel-Harvey estuary. Channels used by recreationists to gain information about water quality, the perception of water quality and resulting behaviour were investigated. This study showed that personal perception, local knowledge and history, absence of warnings and residency were major factors contributing to risk perception and behaviour in this recreational community. Management strategies should take this information into account to achieve maximal outcomes.  相似文献   
198.
Contaminated sites pose a significant threat to groundwater resources worldwide. Due to limited available resources a risk-based prioritisation of the remediation efforts is essential. Existing risk assessment tools are unsuitable for this purpose, because they consider each contaminated site separately and on a local scale, which makes it difficult to compare the impact from different sites. Hence a modelling tool for risk assessment of contaminated sites on the catchment scale has been developed. The CatchRisk screening tool evaluates the risk associated with each site in terms of its ability to contaminate abstracted groundwater in the catchment. The tool considers both the local scale and the catchment scale. At the local scale, a flexible, site specific leaching model that can be adjusted to the actual data availability is used to estimate the mass flux over time from identified sites. At the catchment scale, a transport model that utilises the source flux and a groundwater model covering the catchment is used to estimate the transient impact on the supply well. The CatchRisk model was tested on a groundwater catchment for a waterworks north of Copenhagen, Denmark. Even though data scarcity limited the application of the model, the sites that most likely caused the observed contamination at the waterworks were identified. The method was found to be valuable as a basis for prioritising point sources according to their impact on groundwater quality. The tool can also be used as a framework for testing hypotheses on the origin of contamination in the catchment and for identification of unknown contaminant sources.  相似文献   
199.
农业土壤危险废物污染的风险管理   总被引:2,自引:0,他引:2  
从环境风险管理出发,探讨危险废物对农业土壤污染的途径,提出土壤危险废物污染的风险管理内容和方法,初步建立辽宁省农业土壤危险废物污染的预警指标体系。  相似文献   
200.
Perfluorinated compounds (PFCs) were measured in zooplankton and five fish species collected from Gaobeidian Lake, which receives discharge from wastewater treatment plant (WWTP) in Beijing, China. The mean total PFCs in five fish were in the order: crucian carp > common carp > leather catfish > white semiknife carp > tilapia. Perfluorooctane sulfonate (PFOS) occurred at the greatest concentrations, with mean concentrations ranging from 5.74 to 64.2 ng/ml serum. Perfluorodecanoic acid (PFDA) was the second dominant PFC in fish samples except for common carp in which perfluorooctane sulfonamide (PFOSA) was dominant. A positive linear relationship (r2 = 0.85, p < 0.05) was observed between ln PFOS concentrations (ln ng/ml) and trophic level (based on δ15N) if tilapia was excluded. The risk assessment showed that PFOS might not pose an immediate risk to fish in Gaobeidian Lake.  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