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831.
为研究济南市机动车排气对城市区域空气质量的影响,利用环境空气质量监测站点(简称"1号站点")和路边机动车尾气监测站点(简称"2号站点")的在线数据,以及基于4种模拟情景的CMAQ空气质量模型预测数据,研究了济南市城市区域大气污染物质量浓度变化规律及不同机动车车型对6种常规大气污染物的贡献.结果表明:①在采暖季,1号站点ρ(PM2.5)、ρ(PM10)、ρ(NO2)、ρ(CO)、ρ(O3)和ρ(SO2)月均值分别为435 μg/m3、702 μg/m3、84.2 μg/m3、6.8 mg/m3、4.5 μg/m3和92 μg/m3.②2015年12月24日(灰霾天),1号站点ρ(CO)、ρ(PM2.5)和ρ(PM10)均明显升高,ρ(SO2)、ρ(O3)和ρ(NO2)均变化不明显.2个监测站点中ρ(NO2)和ρ(PM10)均呈双峰趋势,2个峰值出现的时间与上、下班高峰期基本一致.除ρ(O3)和ρ(SO2)达GB 3095-2012《环境空气质量标准》二级标准外,其他污染物均超过GB 3095-2012二级标准限值,采暖季大气污染特征为颗粒物型污染.③机动车对研究区域NO2和PM10贡献率较大,其中,小型车对CO、NO2、PM10和PM2.5贡献率最大,其贡献率分别为85.7%、50.1%、53.4%和52.8%.机动车排放源能降低空气中ρ(O3),其总贡献率为-25.5%,其中大型车、中型车、小型车对O3的贡献率分别为-8.8%、-2.7%和-8.9%.灰霾天下不同机动车车型对空气中污染物质量浓度的总贡献率均比采暖季大.研究显示,济南市采暖季大气污染特征为颗粒物型污染,机动车排放源对空气中NO2和PM2.5有较大贡献.   相似文献   
832.
改善空气质量,减少机动车尾气对雾霾的贡献已是当务之急.防治机动车尾气污染,关键是国家应制定和完善相应的法律、法规、规章和标准,出台鼓励新能源机动车的研发、生产、销售的优惠政策.环保部门要把住机动车环保检测第一关,严格机动车环保绿色标志的发放,会同工商部门对油品实行日常监管,加强环保宣传、提高人们的环保意识.公安、环保联动执法,杜绝超标车上路,淘汰黄标车.政府相关部门要科学规划和绿化城市道路.  相似文献   
833.

Background

Little has been published on changes in young driver fatality rates over time. This paper examines differences in Australian young driver fatality rates over the last decade, examining important risk factors including place of residence and socioeconomic status (SES).

Methods

Young driver (17-25 years) police-recorded passenger vehicle crashes were extracted from New South Wales State records from 1997-2007. Rurality of residence and SES were classified into three levels based on drivers’ residential postcode: urban, regional, or rural; and high, moderate, or low SES areas. Geographic and SES disparities in trends of fatality rates were examined by the generalized linear model. Chi-square trend test was used to examine the distributions of posted speed limits, drinking driving, fatigue, seatbelt use, vehicle age, night-time driving, and the time from crash to death across rurality and socioeconomic status.

Results

Young driver fatality rate significantly decreased 5% per year (p < 0.05); however, stratified analyses (by rurality and by SES) showed that only the reduction among urban drivers was significant (average 5% decrease per year, p < 0.01). The higher relative risk of fatality for rural versus urban drivers, and for drivers of low versus high SES remained unchanged over the last decade. High posted speed limits, fatigue, drink driving and seatbelt non-use were significantly associated with rural fatalities, whereas high posted speed limit, fatigue, and driving an older vehicle were significantly related to low SES fatality.

Conclusion

The constant geographic and SES disparities in young driver fatality rates highlight safety inequities for those living in rural areas and those of low SES. Better targeted interventions are needed, including attention to behavioral risk factors and vehicle age.  相似文献   
834.
在分析军用车辆交通事故预测技术重要性的基础上,根据2005—2009年的军用车辆交通事故原始数据,建立军车交通事故的GM(1,1)灰色预测模型。对军用车辆交通事故起数和死亡人数进行短期预测,并通过实例验证预测模型的适用性。通过模型验证结果可以看出:GM(1,1)模型预测所得数据较为精确。预测结论如下:未来几年,军车交通事故会稳步下降,事故发生次数会快速减少,但死亡人数相对减少较缓。  相似文献   
835.
Air pollution and its control in China   总被引:2,自引:0,他引:2  
The rapid growth of China’s economy has led to severe air pollution characterized by acid rain, severe pollution in cities, and regional air pollution. High concentrations are found for various pollutants such as sulfur dioxides (SO2), nitrogen oxides (NOx), and fine particulates. Great efforts have thus been undertaken for the control of air pollution in the country. This paper discusses the development and application of appropriate technologies for reducing the major pollutants produced by coal and vehicles, and investigates air quality modeling as an important support for policy-making.  相似文献   
836.
针对分布式驱动电动汽车紧急制动工况下电机力矩与液压制动力矩的协调控制问题,提出一种制动防抱死双路控制策略。所提控制策略中,基于滑模变结构控制理论对液压制动系统进行制动防抱死控制,同时基于反模型控制理论对电机输出转矩进行调节。通过搭建包括双电机独立驱动系统的半实物仿真平台,进行了所提控制策略的仿真验证,证明所提控制策略能够使车轮滑移率更好跟随理想值,从而显著缩短紧急制动时的制动距离与制动时间。  相似文献   
837.
机动车排放颗粒物采集系统参数的研究和测试   总被引:3,自引:0,他引:3  
机动车排放颗粒物是重要的空气污染物.笔者主要阐述了机动车排放颗粒物采集系统开发和研制过程中部分实验参数的研究和确定,同时给出了初步测试的结果,这些结果在一定程度上表征了机动车排入颗粒物的污染状况.   相似文献   
838.
通过 1997年 7月谭裕沟隧道内CO ,SO2 和NOx 的连续分析 ,研究了其污染状况和特征 ,根据分析结果计算了机动车排放CO ,SO2 和NOx的平均排放因子。结果表明 ,机动车能排放出较高水平的CO和NOx,在城市中CO和NOx 有相当大的部分来源于机动车排放 ,而SO2 的排放量则非常小  相似文献   
839.
利用OBS2200车载测试系统,对天津市的道路行驶车辆进行测试,在3种不同交通流特征(交通高峰期、低峰期和平峰期)下获得了道路车载排放污染物(HC、CO、NOx和CO2)的逐秒数据,结果显示,高峰期HC和CO平均排放率(0.027±0.018 g/s和0.330±0.196 g/s)明显高于低峰期和平峰期,大约分别是低峰期的5.4倍和4.3倍,平峰期的3.9倍和9.2倍。低峰期NOx和CO2平均排放率(0.006±0.006 g/s和1.904±0.960 g/s)稍高于高峰期和平峰期。加速工况下4种排放物的平均排放率:0.022±0.019 g/s、0.243±0.234 g/s、0.007±0.007 g/s和1.766±0.946 g/s,大约分别是减速工况下4种排放物平均排放率的1.1倍、1.4倍、2.3倍和1.9倍。随着加速度增大4种排放物的排放率逐渐增大。  相似文献   
840.
Objective: Characterization of the severity of injury should account for both mortality and disability. The objective of this study was to develop a disability metric for thoracic injuries in motor vehicle crashes (MVCs) and compare the functional outcomes between the pediatric and adult populations.

Methods: Disability risk (DR) was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank for the most frequently occurring Abbreviated Injury Scale (AIS) 2–5 thoracic injuries. Occupants with thoracic injury were classified as disabled or not disabled based on the FIM scale, and comparisons were made between the following age groups: pediatric, adult, middle-aged, and older occupants (ages 7–18, 19–45, 46–65, and 66+, respectively). For each age group, DR was calculated by dividing the number of patients who were disabled and sustained a given injury by the number of patients who sustained a given injury. To account for the effect of higher severity co-injuries, a maximum AIS adjusted DR (DRMAIS) was also calculated for each injury. DR and DRMAIS could range from 0 to 100% disability risk.

Results: The mean DRMAIS for MVC thoracic injuries was 20% for pediatric occupants, 22% for adults, 29% for middle-aged adults, and 43% for older adults. Older adults possessed higher DRMAIS values for diaphragm laceration/rupture, heart laceration, hemo/pneumothorax, lung contusion/laceration, and rib and sternum fracture compared to the other age groups. The pediatric population possessed a higher DRMAIS value for flail chest compared to the other age groups.

Conclusion: Older adults had significantly greater overall disability than each of the other age groups for thoracic injuries. The developed disability metrics are important in quantifying the significant burden of injuries and loss of quality life years. Such metrics can be used to better characterize severity of injury and further the understanding of age-related differences in injury outcomes, which can influence future age-specific modifications to AIS.  相似文献   

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