全文获取类型
收费全文 | 1848篇 |
免费 | 195篇 |
国内免费 | 13篇 |
专业分类
安全科学 | 1424篇 |
废物处理 | 5篇 |
环保管理 | 77篇 |
综合类 | 223篇 |
基础理论 | 68篇 |
污染及防治 | 6篇 |
评价与监测 | 11篇 |
社会与环境 | 5篇 |
灾害及防治 | 237篇 |
出版年
2023年 | 27篇 |
2022年 | 60篇 |
2021年 | 69篇 |
2020年 | 92篇 |
2019年 | 72篇 |
2018年 | 36篇 |
2017年 | 60篇 |
2016年 | 46篇 |
2015年 | 70篇 |
2014年 | 60篇 |
2013年 | 67篇 |
2012年 | 169篇 |
2011年 | 142篇 |
2010年 | 97篇 |
2009年 | 109篇 |
2008年 | 60篇 |
2007年 | 144篇 |
2006年 | 162篇 |
2005年 | 96篇 |
2004年 | 97篇 |
2003年 | 67篇 |
2002年 | 50篇 |
2001年 | 57篇 |
2000年 | 25篇 |
1999年 | 23篇 |
1998年 | 27篇 |
1997年 | 16篇 |
1996年 | 21篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有2056条查询结果,搜索用时 6 毫秒
451.
452.
采用层次分析法对热磨试间火灾爆炸风险进行分析,以某企业热磨试间内热磨合作业过程为例建立了评价模型。为提高层次分析法的准确性和有效性,在层次分析法之前,引入事故树,通过事故树确定各级指标,在层次分析法之后,通过与模糊数学相结合,对模型进行模糊评价,得出模型所处等级D=0.7087,即该企业热磨试间火灾爆炸风险为"危险性较大"等级。研究表明,"事故树-模糊层次分析法"应用于热磨试间火灾爆炸风险分析是可行的,有助于企业有针对性地制定安全措施,预防热磨试间火灾爆炸事故的发生。 相似文献
453.
Lin Zhou Gui Fu Yujingyang Xue 《International journal of occupational safety and ergonomics》2018,24(3):329-340
Human and organizational factors have been proven to be the prime causes of Chinese hazardous chemical accidents (HCAs). A modified version of the Human Factors Analysis and Classification System (HFACS), namely the HFACS-Hazardous Chemicals (HC), was developed to identify the human factors involved in Chinese HCAs. The ‘8.12’ Tianjin Port fire and explosion, the costliest HCA in recent years, was reanalyzed using this framework, and the results were compared with the official accident inquiry report to determine their differences related to the identification of human and organizational factors. The study revealed that interacting human factors from different levels in Ruihai Company led to this catastrophe, and the inquiry report had limitations in the identification of human factors and the guidance for similar accident prevention. This study showed the applicability of the HFACS-HC in HCA analyses as well as the necessity to recommend this approach for future HCA investigations. 相似文献
454.
GLENN R. MATLACK 《Conservation biology》2013,27(5):916-926
Prescribed burning is increasingly being used in the deciduous forests of eastern North America. Recent work suggests that historical fire frequency has been overestimated east of the prairie–woodland transition zone, and its introduction could potentially reduce forest herb and shrub diversity. Fire‐history recreations derived from sedimentary charcoal, tree fire scars, and estimates of Native American burning suggest point‐return times ranging from 5–10 years to centuries and millennia. Actual return times were probably longer because such records suffer from selective sampling, small sample sizes, and a probable publication bias toward frequent fire. Archeological evidence shows the environmental effect of fire could be severe in the immediate neighborhood of a Native American village. Population density appears to have been low through most of the Holocene, however, and villages were strongly clustered at a regional scale. Thus, it appears that the majority of forests of the eastern United States were little affected by burning before European settlement. Use of prescribed burning assumes that most forest species are tolerant of fire and that burning will have only a minimal effect on diversity. However, common adaptations such as serotiny, epicormic sprouting, resprouting from rhizomes, and smoke‐cued germination are unknown across most of the deciduous region. Experimental studies of burning show vegetation responses similar to other forms of disturbance that remove stems and litter and do not necessarily imply adaptation to fire. The general lack of adaptation could potentially cause a reduction in diversity if burning were introduced. These observations suggest a need for a fine‐grained examination of fire history with systematic sampling in which all subregions, landscape positions, and community types are represented. Responses to burning need to be examined in noncommercial and nonwoody species in rigorous manipulative experiments. Until such information is available, it seems prudent to limit the use of prescribed burning east of the prairie–woodland transition zone. Reevaluación del Uso de Fuego como Herramienta de Manejo en Bosques Deciduos de América del Norte 相似文献
455.
Natural disasters such as large earthquakes may rapidly result in cascading events such as post-earthquake fires (PEFs) to trigger. This is particularly the case in industrial facilities which is well known as natural-hazard triggered technological accidents (NaTechs). This study provides a response framework for NaTechs caused by earthquake in fuel storage facilities. To do this, seismic vulnerability of fuel storage tanks and possible damage fashions are studied. Considering fuel leakages can result in PEFs, possible scenarios are simulated numerically using Process Hazard Analysis Software Tool (PHAST). A case study including 20 fuel tanks adjacent one to another is investigated to simulate a domino effect when different arbitrary tanks start to ignite; hence, the worst case scenario can be determined. Based on the results of the case studied, inability to extinguish the possible PEFs over less than 9 min can lead to spreading them to the adjacent tanks. The results indicate that it takes about 40 min the adjacent tanks involve in the fires. Therefore, it is of paramount importance to provide an emergency response plan in advance to properly respond to the fires. The study here also highlights the role of preventive strategies in reducing the associated risks of PEFs in industrial facilities. 相似文献
456.
457.
为提高复杂连体宿舍楼的火灾应急疏散效率,以某高层连体复杂宿舍楼为例,运用PyroSim对该复杂连体宿舍楼发生火灾时的烟气蔓延特性以及不同楼体之间的相互影响进行模拟,运用Pathfinder对该宿舍楼的人员疏散进行仿真模拟。火灾模拟结果表明:连体宿舍楼中,连廊对整栋楼的安全至关重要,建议加强对连廊的消防管理。疏散模拟结果表明:中间连廊保持正常通行可以有效提高疏散效率;连体复杂宿舍楼不适合男女混住,应该根据建筑物结构合理安排居住人员;增加2~3层连廊,并设置可移动式外挂楼梯,同时确保发生紧急事故时应急疏散指导人员正确快速地引导人员进行疏散,可以有效提高疏散效率。研究方法和结果可为复杂连体宿舍楼的消防措施、建筑设计以及宿舍楼应急管理提供参考和借鉴。 相似文献
458.
Tropical forests are experiencing enormous threats from deforestation and habitat degradation. Much knowledge of the impacts of these land-use changes on tropical species comes from studies examining patterns of richness and abundance. Demographic vital rates (survival, reproduction, and movement) can also be affected by land-use change in a way that increases species vulnerability to extirpation, but in many cases these impacts may not be manifested in short-term changes in abundance or species richness. We conducted a literature review to assess current knowledge and research effort concerning how land-use change affects species vital rates in tropical forest vertebrates. We found a general paucity of empirical research on demography across taxa and regions, with some biases toward mammals and birds and land-use transitions, including fragmentation and agriculture. There is also considerable between-species variation in demographic responses to land-use change, which could reflect trait-based differences in species sensitivity, complex context dependencies (e.g., between-region variation), or inconsistency in methods used in studies. Efforts to improve understanding of anthropogenic impacts on species demography are underway, but there is a need for increased research effort to fill knowledge gaps in understudied tropical regions and taxa. The lack of information on demographic impacts of anthropogenic disturbance makes it difficult to draw definite conclusions about the magnitude of threats to tropical ecosystems under anthropogenic pressures. Thus, determining conservation priorities and improving conservation effectiveness remains a challenge. 相似文献
459.
460.
Currently, novel energy resources are receiving increasing attention as a response to the limitation in fossil fuels as well as their adverse effects on human health. Hydrogen, one of the most abundant elements on the earth, can be regarded as a new energy source to replace fossil fuels. Therefore, safety assessment of the relating processes is very crucial by increasing use of hydrogen as a fuel source. In this regard, consequence analysis for risk assessment and power reduction is very important. The present study aims at modeling hydrogen dispersion along with consequence analyses for such events as jet fire and flash fire. The model was validated by using the data derived from a study on hydrogen leakage in supply pipelines in the laboratory of the University of Pisa. Modeling results reveal that ambient conditions will impose a milder impact on leakage consequences if internal pressure is high in release source. The safe distance was also estimated to be 14 m. Dispersion consequence modeling was performed, followed by the evaluation of the effect of environmental (i.e., stability, ambient temperature, surface roughness, wind speed, and humidity) and process (i.e., vessel temperature and pressure, leakage diameter, and releasing point height) parameters on maximum size flammable vapor cloud and maximum level jet fire radiation on the ground. The size of flammable vapor cloud (consequence dispersion index) and the maximum flux of radiation were affected by process parameters more than ambient parameters. Leakage diameter and the vessel pressure were found to have the highest impact on the operational parameters. 相似文献