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31.
Objectives: Engaging in active transport modes (especially walking) is a healthy and environmentally friendly alternative to driving and may be particularly beneficial for older adults. However, older adults are a vulnerable group: they are at higher risk of injury compared with younger adults, mainly due to frailty and may be at increased risk of collision due to the effects of age on sensory, cognitive, and motor abilities. Moreover, our population is aging, and there is a trend for the current cohort of older adults to maintain mobility later in life compared with previous cohorts. Though these trends have serious implications for transport policy and safety, little is known about the contributing factors and injury outcomes of pedestrian collision. Further, previous research generally considers the older population as a homogeneous group and rarely considers the increased risks associated with continued ageing.

Method: Collision characteristics and injury outcomes for 2 subgroups of older pedestrians (65–74 years and 75+ years) were examined by extracting data from the state police–reported crash dataset and hospital admission/emergency department presentation data over the 10-year period between 2003 and 2012. Variables identified for analysis included pedestrian characteristics (age, gender, activity, etc.), crash location and type, injury characteristics and severity, and duration of hospital stay. A spatial analysis of crash locations was also undertaken to identify collision clusters and the contribution of environmental features on collision and injury risk.

Results: Adults over 65 years were involved in 21% of all pedestrian collisions. A high fatality rate was found among older adults, particularly for those aged 75 years and older: this group had 3.2 deaths per 100,000 population, compared to a rate of 1.3 for 65- to 74-year-olds and 0.7 for adults below 65 years of age. Older pedestrian injuries were most likely to occur while crossing the carriageway; they were also more likely to be injured in parking lots, at driveway intersections, and on sidewalks compared to younger cohorts. Spatial analyses revealed older pedestrian crash clusters on arterial roads in urban shopping precincts. Significantly higher rates of hospital admissions were found for pedestrians over the age of 75 years and for abdominal, head, and neck injuries; conversely, older adults were underrepresented in emergency department presentations (mainly lower and upper extremity injuries), suggesting an increased severity associated with older pedestrian injuries. Average length of hospital stay also increased with increasing age.

Conclusion: This analysis revealed age differences in collision risk and injury outcomes among older adults and that aggregate analysis of older pedestrians can distort the significance of risk factors associated with older pedestrian injuries. These findings have implications that extend to the development of engineering, behavioral, and enforcement countermeasures to address the problems faced by the oldest pedestrians and reduce collision risk and improve injury outcomes.  相似文献   
32.
为了更好地服务于矿山安全管理,同时解决矿山人为因素调查、分析和评价方面存在的缺失,对部分矿山事故进行了统计分析,研究了诱发事故发生的人因因素,并分析了各因素发生的原因。在此基础上,结合对部分矿山安全管理现状的研究,建立了矿山HFACS分析模型。该模型包括5类事故致因、24个人因因素。应用该模型,结合集对分析方法,可实现矿山人因因素定量与定性分析。以陕西省某矿山为例,建立了该矿山的HFACS模型。采用专家评分法、层次分析法确定各因素的权重,计算出系统的联系度表达式。利用该表达式对该矿山的集对势、联系度、不确定性和悲观势进行了分析。结果表明,该矿山人因安全状况良好,个别人因因素指标需要改善和提高。矿山HFACS模型可以很好地涵盖矿山事故中的人因因素,通过对矿山人因现状的集对分析,可以有效提高矿山安全性。  相似文献   
33.
为了计算综放工作面沿空留巷支护阻力,以结构力学理论为基础,分析综放工作面沿空留巷支护阻力计算模型,建立沿空留巷围岩和支护体的结构力学模型,应用超静定结构和静定结构分析支护体与沿空留巷围岩相互作用机制,推导出巷旁支护阻力的计算公式.结果表明,进行沿空留巷支护阻力力学分析时,要考虑顶板极限断裂前和断裂后两种状态下的受力情况,支护阻力与岩层厚度、容重、煤体极限平衡区宽度、跨距、支护体宽度和巷道宽度等因素密切相关.工业性试验表明,该技术的应用是成功而有效的.因此,综放巷内沿空留巷围岩结构力学模型和支护阻力计算公式是合理的,可在类似条件的综放工作面中应用.  相似文献   
34.
为研究平顶山矿区东西分区的特征,对比多种因素,分析矿区东西区的瓦斯分布特征、突出分布特征和构造煤分布规律,论述地应力和瓦斯耦合对东部矿区突出的控制作用。结果表明,东区瓦斯含量和突出强度明显高于西区,原因是其受控于东区褶皱区,地应力和瓦斯耦合控制着东区的突出;而锅底山断层的形成及其后期演化使西区突出危险性小于东区。东西地质构造的不同,不但导致构造煤、瓦斯含量分布不同,而且给地应力与瓦斯耦合提供了不同的条件。总之,东部褶皱区是造成东区与西区产生明显分区性差异的关键影响因素。  相似文献   
35.
突发事件情景演化及关键要素提取方法   总被引:1,自引:0,他引:1  
针对突发事件应急处置难度大的特点,突发事件应急管理模式必须向"情景-应对"转变。从系统复杂性、开放式预先设想以及序贯性三个主要原则的角度理解突发事件情景演化的机理,构建了突发事件情景演化系统模型,并以此为基础设计了突发事件情景网络关键要素的提取方法。该方法以危险源形成、突发事件演化以及应急响应三方面主要内容为情景网络的主体,以三方面主要内容所涉及的影响因素为分支,适当的选取情景网络关键要素并将关键要素分为四类。该方法的提出弥补了情景网络关键要素提取方法理论的空白,为突发事件情景构建提供了理论支持。  相似文献   
36.
为减少风险分级排序时产生的风险结,在引入施工安全事故频率的基础上,采用单元格细化和Borda序值法改进原有的风险矩阵法。改进后的方法使得风险等级数量增加,风险结数量减少。将该方法应用于脚手架工程的风险因素的分级与排序,风险等级分为6级,且实现了12个因素的明确排序。  相似文献   
37.
Introduction: More than 800 pedestrians die annually in crashes on interstates and other freeways in the United States, but few studies have examined their characteristics. Method: Data from the Fatality Analysis Reporting System on pedestrians fatally injured during 2015–2017 were analyzed. Chi-square tests compared characteristics of pedestrians killed on interstates and other freeways with those that died on other roads, and across crash types among freeway deaths. Land use characteristics of locations where pedestrians were killed while crossing freeways in a large state (California) were identified using Google Earth. Results: A larger proportion of pedestrians killed on freeways died on dark and unlit roads (48% vs. 32%), were male (78% vs. 68%), or were ages 20–44 (55% vs. 32%) compared with pedestrians killed on other roads. Crossing (42%) was the most common crash type among pedestrian deaths on freeways, followed by disabled-vehicle-related crashes (18%). Pedestrians who died while crossing more often had blood alcohol concentrations ≥ 0.08 g/dL (40%) than those in disabled-vehicle-related (22%) or other crashes (34%). Deaths in crossing crashes were more likely than other freeway deaths to occur on urban roads (81%), at speed limits ≤50 mph (13%), or between 18:00 and 23:59 (49%), and 58% of crossing crashes analyzed for land use were located between residential and other (e.g., commercial, recreational) uses. Over a third (37%) of deaths in disabled-vehicle-related crashes occurred at speed limits ≥70 mph. Conclusions: A surprising proportion of pedestrian deaths occur on controlled-access roads not designed for walking. Countermeasures for these crashes need to be implemented to see meaningful reductions in pedestrian fatalities overall. Practical applications: Improving roadway and vehicle lighting, requiring reflective warning devices for marking disabled vehicles, constructing pedestrian overpasses and underpasses in areas frequently crossed, and promoting alternative means of traveling between residential and commercial areas could help.  相似文献   
38.
文章明确了挥发性油藏天然气回注井控的安全环保关键因素;量化了低渗挥发性油藏天然气回注注入能力,确定注入端各节点安全生产压力分布,攻关相关配套工艺设备,实现安全有效注入;开展室内实验和PVT相态拟合,分析注天然气后天然气和原油性质变化规律,创新非混相驱组分数值模拟参数优化方法,开展带人工压裂裂缝的组分数值模拟,精准确定压力场分布,降低计量及监测不准带来的安全隐患;明确注气井气窜影响因素,优化注采参数,抑制油井气窜,降低生产风险,实现井控安全情况下的天然气驱环保高效开发。  相似文献   
39.
本文讨论了通过建立奖励与惩罚相结合的检验理念,采取全面检验与重点检验相结合的检验方式,使选择优质维保单位的电梯使用单位可支付更少的电梯检验费,而选择劣质维保单位的电梯使用单位则须支付更多的电梯检验费,从而促使电梯使用单位自觉选择优质维保单位.希望通过这种方式能够呈现择优汰劣的电梯维保市场,保证电梯的维保质量和安全质量.  相似文献   
40.
异养硝化-好氧反硝化菌粪产碱杆菌的脱氮特性   总被引:4,自引:0,他引:4  
为了对粪产碱杆菌(Alcaligenes faecalis No.4)的脱氮特性进行研究,提出了不同环境因子对菌株脱氮性能影响的对比实验。结果表明,该菌能利用柠檬酸钠和乙酸钠作为惟一碳源,以柠檬酸钠为碳源时脱氮活性最高,硝酸铵、氯化铵、碳酸铵和硫酸铵4种铵盐均能作为惟一氮源,而硝态氮和亚硝态氮几乎不能被该菌代谢转化;当温度在30~37℃、摇床转速超过120 r/min、p H为6~8之间时,该菌对氨氮的去除效果最好;该菌对高中低浓度的氨氮都具有很好的去除效果,对高浓度的氨氮有很好的耐受性;该菌对0%、3%盐度的适应期较短,对6%的盐度经过较长时间的适应期后,也能够快速地处理氨氮,具有良好的耐盐性。  相似文献   
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