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   263篇
  免费   57篇
  国内免费   164篇
安全科学   71篇
废物处理   12篇
环保管理   13篇
综合类   306篇
基础理论   16篇
污染及防治   18篇
评价与监测   37篇
社会与环境   4篇
灾害及防治   7篇
  2024年   6篇
  2023年   21篇
  2022年   33篇
  2021年   43篇
  2020年   46篇
  2019年   30篇
  2018年   23篇
  2017年   14篇
  2016年   14篇
  2015年   18篇
  2014年   25篇
  2013年   38篇
  2012年   22篇
  2011年   16篇
  2010年   17篇
  2009年   16篇
  2008年   9篇
  2007年   8篇
  2006年   9篇
  2005年   9篇
  2004年   11篇
  2003年   14篇
  2002年   7篇
  2001年   6篇
  2000年   5篇
  1999年   4篇
  1998年   1篇
  1997年   4篇
  1996年   6篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
  1987年   1篇
  1986年   1篇
排序方式: 共有484条查询结果,搜索用时 31 毫秒
111.
加油站油气回收系统是由卸油油气回收系统、汽油密闭储存、加油油气回收系统、在线监测系统和油气排放处理装置组成。该系统的作用是将加油站在卸油、储油和加油过程中产生的油气,通过密闭收集、储存和送入油罐汽车的罐内,运送到储油库集中回收变成汽油,以达到在汽车加油、油料储运过程中油汽不外泄,不污染周边环境的目的。根据中华人民共和国《加油站大气污染物排放标准》(GB 20952-2007)中第六条的规定,长三角地区的改造项目应在2010年1月1日进行,因此对加油站油气回收系统的监测显得十分紧迫。  相似文献   
112.
Dry deposition velocities and fluxes of PM10during Asian dust events over the Yellow Sea from 2001 to 2007 were investigated using observation data in Qingdao, China and Jeju, Korea. The dry deposition velocities of PM10 during dust events over the Yellow Sea ranged from 0.19 to 8.17 cm/sec, with an average of 3.38 cm/sec. Dry deposition fluxes of PM10during dust events over the Yellow Sea were in the range of 68.5–2647.1 mg/(m2·day), with an average of 545.4 mg/(m2·day), which is 2–10 times higher than those reported by other studies for both dust and non-dust periods. It was estimated that 2.6 × 1011–48.7 × 1011g dust particles deposit to the Yellow Sea during dust events through dry deposition every year. Compared with the results in previous studies, it was found that the dry deposition of PM10over the Yellow Sea during dust events in the years with high frequency of dust could account for a large or overwhelming fraction of the annual total dry deposition. Backward air mass trajectory analysis showed that dust events influenced Jeju mainly originated from the desert regions located in Mongolia and Inner Mongolia, China. There were 119 backward trajectories influenced both Qingdao and Jeju during 15 dust events from 2001 to 2007, accounting for 61.3% of the total trajectories of 194, indicating that Qingdao and Jeju were usually on the same pathway of dust transport downwind from source areas.  相似文献   
113.
INTRODUCTION: Although Musculoskeletal Disorders (MSD) represent a common occupational problem, few epidemiological studies have investigated MSD risk factors among Asian nurses, particularly those in Japan. METHOD: We administered a modified Japanese-language version of the Standardized Nordic Questionnaire to 1,162 nurses from a large teaching hospital. MSD categories focused on the neck, shoulder, upper back, and lower back regions. RESULTS: A total of 844 completed questionnaires were analyzed (response rate: 72.6%). The 12-month period-prevalence of MSD at any body site was 85.5%. MSD was most commonly reported at the shoulder (71.9%), followed by the lower back (71.3%), neck (54.7%), and upper back (33.9%). Alcohol consumption, tobacco smoking, and having children were shown to be significant risk factors, with adjusted Odds Ratios of 1.87 (95%CI: 1.17-2.96), 2.45 (95%CI: 1.43-4.35), and 2.53 (95%CI: 1.32-4.91), respectively. Workplace risk factors included manually handling patients (OR: 2.07 to 11.97) and undertaking physically laborious work (OR: 2.09 to 2.76). Nurses reporting pre-menstrual tension were 1.66 and 1.94 times more likely to suffer from lower back and upper back MSD, respectively. High mental pressure was also identified as a significant risk factor for MSD of the neck (OR: 1.53) and shoulder (OR: 2.07). IMPACT ON INDUSTRY: The complex nature of MSD risk factors identified during this study suggests that remediation strategies which focus only on manual handling tasks would probably be suboptimal in reducing MSD among nurses. Therefore, to help alleviate their considerable MSD burden, a greater emphasis will need to be placed on job satisfaction, work organization, and occupational stress, as well as the more traditional hazard reduction strategies such as manual handling, work tasks, and other occupational factors.  相似文献   
114.
《组织行为杂志》2017,38(5):671-691
Drawing on gestalt characteristics theory, we advance the literature on the effect of job complexity on employee well‐being by considering intra‐individual variability of job complexity over time. Specifically, we examine how the trend, or trajectory, of job complexity over time can explain unique variance of employee job strain. Across two longitudinal data sets, we consistently find that, with the average level of job complexity during a given period held constant, a positive job complexity trajectory (i.e., an increasing trend in complexity) is associated with higher employee job strain. Based on job‐demand‐control theory and the exposure‐reactivity model, we further establish that job autonomy and employee emotional stability jointly moderate the relationship between job complexity trajectory and employee job strain. Specifically, for employees with high emotional stability, job autonomy mitigates the job strain brought by positive job complexity trajectory, whereas for employees with low emotional stability, job autonomy does not help to reduce the adverse effect of the increasing trend. These findings not only contribute to extend the understanding of the job complexity – strain relationship, but also suggest a promising, dynamic avenue to study the effects of work characteristics on employee well‐being as well as other outcomes. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
115.
从调查316名汽车组装流水线作业工人的慢性肌肉损伤情况中发现,其主要不适有右手或右肩的疲劳、下背痛、手腕压痛、前臂压痛及下背压痛等。汽车组装流水作业工人的这些症状和体征与其工作时右上肢活动明显多于左上肢及常处于前倾弯腰体位有关  相似文献   
116.
介绍了一种新型的煤气回火安全装置,说明了它的工作原理,主要参数,工艺结构等,叙述了其研制过程和应用情况。  相似文献   
117.
电除尘器粉尘层反电晕击穿厚度理论与试验   总被引:1,自引:0,他引:1  
为了合理地确定静电除尘器清灰振打周期,通过理论与试验方法确定静电除尘器粉尘层反电晕击穿厚度很有必要的。首先基于静电学理论导出带电粉尘层内的电量分布和电场分布数学模型,然后根据粉尘层反电晕发生条件,得出粉尘层反电晕击穿厚度的计算式,结果表明,反电晕击穿厚度是粉尘比电阻、电晕电流密度及极配的函数。通过对高比电阻不同厚度的粉尘层的反电晕击穿试验研究,结果表明,各击穿点的连线呈较连续光滑的弧线,提出了利用伏安特性曲线确定粉尘层反电晕击穿厚度的简易图解法。  相似文献   
118.
Analysis and Case Study of Duststorms in the Beijing Area   总被引:4,自引:0,他引:4  
Dust weather conditions with strong wind often occur in Beijing during spring. The number of duststorms in Beijing has declined since 1954. In the last two years, however, the number of duststorms in Beijing has increased drastically due to frequent cold air movements and the deteriorated ecological environment. The heaviest duststorm in the last decade in Beijing occurred on 6 April 2000. It was caused by the development of a high-level small trough along with strong northwest wind behind a large trough that moved eastward and developed a strong cold air system. A non-hydrostatic meso-scale numerical model (MM5) gave a good forecast to the duststorm's major features and movement. Simulated results showed that there was a strong vertical ascending motion with a strong positive vorticity center in mid and low level. The mesoscale structure's formation and development and movement were consistent with the passage and moving direction of the duststorm. At the same time, the trajectories of air particles during this duststorm event and another case (on 27 March 2000) were estimated and analyzed, which had the comparable results with the real situation and the trajectory monitored by meteorological satellite. The trajectories analysis could help us study the transport track and sand source to some extent.  相似文献   
119.
宋锐 《电力环境保护》2003,19(2):30-31,42
介绍了EE型电除尘器在安徽准北发电厂200MW发电机组配套锅炉上的应用情况以及处理高比电阻粉尘的方法。  相似文献   
120.
韩方红  高凡  何兵  曹燕  姚小晨 《环境科学》2024,45(6):3297-3307
土地利用变化会导致不同类型碳源和碳汇功能变化,是碳排放的关键来源.从土地利用变化的角度开展阿克苏河流域碳排放及其影响因素研究,对于促进流域山水林田湖草沙冰一体化保护修复、助力碳达峰与碳中和目标实现具有重要意义.基于1990~2020年的4期土地利用数据与同期社会经济数据,测算土地利用碳排放总量,探究土地利用碳排放时空轨迹及其影响因素.结果表明:①1990~2020年,耕地、林地、建设用地和未利用地整体呈增加趋势,草地和水域呈减少态势.土地利用类型空间变化特征主要表现为草地、未利用地转换为耕地;②1990~2020年流域净碳总排放量呈现持续上升趋势,累计增加了14.78×104 t,耕地面积增加是引起流域净碳排放量增长的关键因素;③流域土地利用碳排放量空间上呈中间高四周低的分布格局,净碳排放量显著变化区域主要分布在温宿县南部、阿克苏市、阿瓦提县及阿拉尔市;④人类活动对土地利用碳排放驱动作用最强且其影响由东部向西部逐渐增大,年均气温对土地利用碳排放影响贡献主要集中在阿克苏市东部和阿瓦提县北部,年均降雨量对温宿县北部和阿合奇县西部的抑制作用较强.  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