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   159篇
  免费   7篇
  国内免费   20篇
安全科学   16篇
环保管理   8篇
综合类   35篇
基础理论   70篇
污染及防治   9篇
评价与监测   6篇
社会与环境   14篇
灾害及防治   28篇
  2024年   1篇
  2023年   1篇
  2022年   3篇
  2021年   4篇
  2020年   5篇
  2019年   7篇
  2018年   4篇
  2017年   4篇
  2016年   13篇
  2015年   3篇
  2014年   2篇
  2013年   21篇
  2012年   5篇
  2011年   11篇
  2010年   17篇
  2009年   10篇
  2008年   7篇
  2007年   9篇
  2006年   11篇
  2005年   5篇
  2004年   11篇
  2003年   2篇
  2002年   6篇
  2001年   5篇
  2000年   4篇
  1999年   3篇
  1998年   2篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1988年   1篇
  1982年   1篇
排序方式: 共有186条查询结果,搜索用时 4 毫秒
121.
我国煤矿安全生产事故呈现逐年大幅度下降的趋势,对比中美煤炭百万吨死亡率,显示,我国与美国相比还存在比较大的差距。继而,通过分析中美煤矿安全监察执法的特点,发现,中美在安全监察执法、职业培训、执法人员权责、煤矿监管监察技术方面存在不同,并针对这几方面提出了进一步完善我国煤矿安全监察工作的建议,可为完善我国安全监察执法体系提供参考和借鉴。  相似文献   
122.
In the seasonally breeding langur (Presbytis entellus) population of Ramnagar, South Nepal, where multimale groups prevail, 25 attacks on 11 infants (including one actual killing) by seven adult males were witnessed in five groups by six observers between 1990 and 1996. Circumstantial evidence also indicates three additional attempts at infanticide and in seven additional cases infanticide was presumed or likely. Infanticide presumably accounted for 30.8–62.5% of infant mortality in the first 2 years of life. Most attackers (91.4%) were residents of the infants' group and had immigrated after the infants had been born (75.0%) or conceived (25.0%). Thus, they were not related to the victims. The interbirth interval was shortened if an infant died either prior to September of its 1st year of life (mean = 1.2 years), or its 2nd year (mean = 2.0) and even its 3rd year (mean = 2.4). All attackers remained in the group at least until the next mating season; high-ranking males maintained their dominance rank and lower-ranking males rose in rank. Since rank and mating success were correlated and rank and reproductive success might be correlated, all attackers had a good chance of siring the next infant of the victims' mothers and could thus have benefited by their action. Infanticide seems to be a male reproductive strategy at Ramnagar. Infanticide has never before been reported among seasonally breeding langurs living at such low densities. This is also the first detailed report of infanticide as a male reproductive strategy in a seasonally breeding primate population. Received: 19 December 1996 / Accepted after revision: 7 June 1997  相似文献   
123.
Air pollution leads to serious negative impacts on health. Thephysical evidence is compelling. An attempt has been made inthis paper to establish dose-response relationship of AmbientAir Quality Index and human health, based on time spent by anindividual in different microenvironments during one day.Economic valuation of morbidity and mortality has been attemptedthrough lost salary approach. The results show that theavoidance cost is 29% of the total health damage cost.  相似文献   
124.
This study reports the probability of increased mortality of people within the political border of Bangladesh due to the emission of fine particulate matter with diameters of 2.5 microns or less (PM2.5) from the Matarbari coal power plant (MCPP). A Gaussian plume dispersion model has been used for this estimation. The PM2.5 emission rate data are unavailable as the construction of MCPP is still in its initial stage; therefore, the anticipated PM2.5 emission rate has been estimated based on data from a number of coal‐fired power plants in India and China. To make this study more meaningful, two different emission rates have been considered representing the best‐case and worst‐case scenarios. In both cases, the intake fraction has been found to be 0.12×10?2, and the value of relative risk varies between 1.134 and 1.374, respectively. Finally, it is estimated that approximately 11.5 million people inside Bangladesh will be exposed to the PM2.5 emission from MCPP, and between 7,667 and 17,675 people will experience premature death every year.  相似文献   
125.
This research measured the mortality rates of pathogen indicator microorganisms discharged from various point and non-point sources in an urban area.Water samples were collected from a domestic sewer,a combined sewer overflow,the effluent of a wastewater treatment plant,and an urban river.Mortality rates of indicator microorganisms in sediment of an urban river were also measured.Mortality rates of indicator microorganisms in domestic sewage,estimated by assuming first order kinetics at 20°C were 0.197 day -1 ,0.234 day -1 ,0.258 day -1 and 0.276 day -1 for total coliform,fecal coliform,Escherichia coli,and fecal streptococci,respectively.Effects of temperature,sunlight irradiation and settlement on the mortality rate were measured.Results of this research can be used as input data for water quality modeling or can be used as design factors for treatment facilities.  相似文献   
126.
廖琴  李勇  陶燕 《环境科学》2024,45(7):3893-3902
为评估大气污染防治行动计划以来,甘肃省PM2.5相关健康影响的时空变化趋势及其驱动因素,应用最新的全球暴露死亡模型(GEMM)估算了2013~2020年甘肃省归因于PM2.5的健康负担,并通过因素分解法进一步探讨了PM2.5归因死亡长期变化的主要原因. 结果表明,2013~2020年,甘肃省人口加权PM2.5浓度下降了34.57%,暴露于PM2.5年均浓度超过35 μg·m-3的人口比例从72.89%大幅下降至11.61%. 研究期间,甘肃省PM2.5归因死亡人数从12 826(95%CI:7 840~17 408)人下降至9 814(95%CI:6 407~13 036)人,下降了23.48%;其中,缺血性心脏病的归因死亡人数有所增加(12.11%),而中风、慢性阻塞性肺病、肺癌和下呼吸道感染的归因死亡人数呈下降趋势;60岁及以上人群的归因死亡人数占80%以上;中东部地区的PM2.5归因死亡人数显著高于河西地区,且大部分地区呈下降趋势;人口规模、年龄结构、基线死亡率和PM2.5浓度在归因死亡人数变化中的贡献分别为-1.26%、16.16%、 -9.84%和-28.55%,人口老龄化和PM2.5浓度降低是PM2.5归因死亡增加和减少的主要因素. 甘肃省积极的清洁空气政策减轻了PM2.5污染造成的健康负担,但在人口老龄化加剧的趋势下,未来需要大幅降低PM2.5浓度才能避免更多的归因死亡.  相似文献   
127.
We model coral community response to bleaching and mass mortality events which are predicted to increase in frequency with climate change. The model was parameterized for the Arabian/Persian Gulf, but is generally applicable. We assume three species groups (Acropora, faviids, and Porites) in two life-stages each where the juveniles are in competition but the adults can enter a size-refuge in which they cannot be competitively displaced. An aggressive group (Acropora species) dominates at equilibrium, which is not reached due to mass mortality events that primarily disadvantage this group (compensatory mortality, >90% versus 25% in faviids and Porites) roughly every 15 years. Population parameters (N individuals, carrying capacity) were calculated from satellite imagery and in situ transects, vital rates (fecundity, mortality, and survival) were derived from the model, field observations, and literature. It is shown that populations and unaltered community structure can persist despite repeated 90% mortality, given sufficiently high fecundity of the remaining population or import from connected populations. The frequency of disturbance determines the dominant group—in low frequency Acropora, in high frequency Porites. This is congruent with field observations. The model of an isolated population was more sensitive to parameter changes than that of connected populations. Highest sensitivity was to mortality rate and recruitment rate. Community composition was sensitive to spacing of disturbances and level of catastrophic mortality. Decreased mortality led to Acropora dominance, increased mortality led to Acropora extinction. In nature, closely spaced disturbances have severely disadvantaged Acropora populations over the last decade. Unless a longer (>10 years) disturbance-free interval can be maintained, a permanent shift away from Acropora dominance will be observed. A mortality rate of 99% in Acropora, as observed in 1996, is not sustainable if repetitive and neither is a disturbance frequency <15 years—each leading to population collapse. This shows that the severity and/or the spacing of the 1996–1998–2002 disturbances were unusual in frequency and duration.  相似文献   
128.
This paper describes an individual-based stochastic model of eastern king prawn migration along the eastern Australian coast. Migration is treated as one-dimensional diffusion with drift. Capture of a prawn is seen as a failure event driven by movement through a spatially and temporally variable fishing mortality hazard. This hazard is combined with a uniform natural mortality hazard. We use a Monte Carlo method to estimate parameters by comparing expected numbers of tag-returns predicted from the model with previously published tag-release data. As the previous study used a discrete compartmental model, with compartments corresponding to zones of constant fishing effort, we used the same zones and fishing effort in our comparison. The marginal distribution of yield in each zone per single recruit is determined, providing more information compared with the deterministic approach to yield-per-recruit. Using our model we also derive the constant fishing mortality rate equivalent to a spatially variable fishing mortality rate in its impact on the proportion of prawns surviving the migration to reach spawning grounds. Determination of this proportion could contribute significantly to a sustainability assessment of the fishery. It is demonstrated using the AIC that better fits to the data of the previous study and greater parsimony are obtained using our model than were found in the deterministic compartmental analysis of that study. This improvement results from the ability of our model to account separately for average speed of movement and average dispersal rate, whereas in the previous deterministic compartmental model, movement is governed by just one parameter. Our individual-based model includes a parameter that explicitly accounts for dispersal of prawns in migration, so it can distinguish between speed effects and dispersal effects in the data. It also models both types of mortality as processes distinct from those of movement. This enables it to better separate movement and mortality effects compared to the compartmental approach, in which movement and mortality are treated as similar departure processes from a compartment. This separation reduces confounding of movement and mortality effects when parameters are estimated.  相似文献   
129.
Schug, Kevin A., Theodore R. Skingel, Sandra E. Spencer, Carlos A. Serrano, Cuong Q. Le, Christopher A. Schug, Theodore W. Valenti, Jr., Bryan W. Brooks, Laura D. Mydlarz, and James P. Grover, 2010. Hemolysis, Fish Mortality, and LC-ESI-MS of Cultured Crude and Fractionated Golden Alga (Prymnesium parvum). Journal of the American Water Resources Association (JAWRA) 46(1):33-44. DOI: 10.1111/j.1752-1688.2009.00389.x Abstract: Erythrocyte lysis and fish mortality assays, in combination with high performance liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis, were investigated for bioassay-guided fractionation of cultured golden alga (Prymnesium parvum). Intracellular constituents from isolated cell pellets and extracellular supernatant growth medium were fractionated by a variety of common separation modes, including reversed phase and normal phase solid phase extraction step fractionation procedures. For reversed phase fractionation of extracellular growth medium, one fraction was obtained that displayed hemolytic activity and adversely affected fish survival. Effective dose concentrations for this sample were similar in both assays and the LC-ESI-MS analysis of the fraction showed a number of mass spectral signals which were distinct to this fraction. Fractions obtained from separation of an ethanol extract of the lyophilized cell pellet provided one sample that was highly hemolytic, but not toxic to fish. Discrepancies such as this, along with notable fish behavioral responses from other nonhemolytic cell pellet fractions, problems with the use of unbonded silica gel for fractionation, and misleading mass spectral signatures are interesting in the context of our current understanding of P. parvum toxicity and remain to be investigated further. This work provides an account of ongoing research aimed toward comprehensive elucidation of toxic constituents produced by golden alga for the purpose of providing a better understanding and means to potentially remediate the ecological impact of this harmful bloom organism.  相似文献   
130.
Risk of flood-related mortality in Nepal   总被引:1,自引:0,他引:1  
In July 1993, severe flooding devastated Sarlahi district in Nepal. The next month, a follow-up study of a large population cohort was undertaken. The study is unique in that a prospective research database was used to verify residency prior to the flood and to confirm vital status afterwards. It evaluated 41,501 children aged between two and nine years and adults aged 15-70 in 7,252 households. Flood-related fatality rates were 13.3 per 1,000 for girls and 9.4 per 1,000 for boys, 6.1 per 1,000 for women and 4.1 per 1,000 for men. Flood-related fatality rates for children were six times higher than mortality rates in the same villages a year before the flood (relative risk (RR) = 5.9, 95 per cent confidence interval (CI) 5.0-6.8). Flood-related fatality was associated with low socio-economic status preflood (RR = 6.4, 95 per cent CI 2.7-20.0), and having a house constructed of thatch (RR = 5.1, 95 per cent CI 1.7-24.5).  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