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   7902篇
  免费   700篇
  国内免费   166篇
电工技术   208篇
综合类   687篇
化学工业   302篇
金属工艺   54篇
机械仪表   257篇
建筑科学   1087篇
矿业工程   75篇
能源动力   126篇
轻工业   2207篇
水利工程   280篇
石油天然气   59篇
武器工业   23篇
无线电   258篇
一般工业技术   596篇
冶金工业   1583篇
原子能技术   40篇
自动化技术   926篇
  2024年   81篇
  2023年   211篇
  2022年   342篇
  2021年   417篇
  2020年   387篇
  2019年   356篇
  2018年   267篇
  2017年   349篇
  2016年   325篇
  2015年   281篇
  2014年   409篇
  2013年   509篇
  2012年   416篇
  2011年   548篇
  2010年   426篇
  2009年   385篇
  2008年   409篇
  2007年   420篇
  2006年   459篇
  2005年   405篇
  2004年   290篇
  2003年   241篇
  2002年   187篇
  2001年   131篇
  2000年   66篇
  1999年   52篇
  1998年   29篇
  1997年   28篇
  1996年   24篇
  1995年   19篇
  1994年   13篇
  1993年   17篇
  1992年   12篇
  1990年   18篇
  1989年   15篇
  1988年   19篇
  1987年   10篇
  1986年   10篇
  1985年   12篇
  1984年   11篇
  1983年   13篇
  1982年   17篇
  1981年   7篇
  1980年   12篇
  1979年   7篇
  1966年   9篇
  1963年   10篇
  1961年   7篇
  1958年   9篇
  1957年   7篇
排序方式: 共有8768条查询结果,搜索用时 15 毫秒
21.
In the world energy about 26% of all was dedved from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information On the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals dudng cleaning, combustion, weathering, and leaching.  相似文献   
22.
Ten areas of health knowledge were investigated in 2 studies, 1 of college students (N=169) and 1 of adults from the community (ages 19-70; N=176). Measures assessed knowledge of aging, orthopedic/ dermatological concerns, common illnesses, childhood/early life, serious illnesses, mental health, nutrition, reproduction, safety, and treatment of illness/disease. Significant gender differences favoring women were found for most areas of health knowledge, especially reproduction and early life. Results showed that cognitive ability accounted for the most variance in health knowledge with nonability (personality and interest traits) and demographic variables accounting for smaller but significant amounts of variance across most knowledge domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
23.
Ecological momentary assessment (EMA) consists of assessing phenomena in real time in the natural environment. EMA allows for more fine-grained analyses of addictive behavior and minimizes threats to internal validity, such as recall biases and errors. However, because of the intensive monitoring involved in EMA, measurement reactivity is a concern. To test whether EMA with palmtop personal computers induces reactivity, the authors compared smoking-related outcomes between smokers using EMA and those not using EMA during a quit attempt. The use of no-EMA control groups has been rare in reactivity investigations to date. The EMA protocol included event-contingent assessments (smoking episodes, urge episodes) and random assessments. Outcomes included biologically confirmed abstinence and self-report measures of withdrawal, self-efficacy, motivation, affect, and temptations. Participants were smokers motivated to quit (N = 96). They were randomized to 1 of 3 groups: EMA for the week preceding a planned quit date, EMA for the week following the quit date, and no EMA. Abstinence rates did not differ between the groups at Day 7 or at Day 28 postcessation. For the 20 subscales assessed at each of 3 assessment times, there were significant differences between participants with and without EMA experience for 3 subscales at the 1st of 3 assessment times, and significant differences for 3 different subscales at the 3rd assessment time. These differences suggest some reactivity to EMA, although the inconsistent pattern across time indicates that further research is needed to definitively conclude that EMA induces reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
24.
Objective: To pilot test a health promotion intervention for women with physical disabilities. Design: Pre- and postintervention questionnaires. Participants: Two groups of women with physical disabilities (n=15). Intervention: Seven-session weekly workshop intervention grounded primarily in social-cognitive theory. Setting: Disability and rehabilitation settings. Main Outcome Measures: Indicators of health status. Results: Statistically significant positive changes between pre- and postintervention scores on measures of self-efficacy for dietary behaviors, medical decision making, social interaction, physical functioning, impact of physical limitation on role activities, and vitality. Conclusion: Women with disabilities who participate in this health promotion intervention may exhibit improvements on indicators of health status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
25.
During the years 1986–1989 The Finnish Work Environment Fund initiated a multicenter, intervention study (programme) to prevent musculoskeletal disorders at work. The programme consisted of four different projects comprising methodological, epidemiological, and interventive themes. The main results were as follows: (1) More than half of the occupational physiotherapists and physicians involved in the project felt that they did not have adequate training for testing the performance capacity of the musculoskeletal system. Several of the most commonly used musculoskeletal tests had either poor validity in predicting future musculoskeletal troubles or had poor reliability. (2) A controlled intervention study showed that active training of neck-shoulder muscles can prevent musculoskeletal troubles, even more than ergonomic actions. (3) It is possible to reduce sick-leave due to low-back disorders by intervention measures directed toward both the work (environment, tools) and the workers (working methods, positive attitude to work, preparedness to keep fit). (4) The identification of ergonomic hazards with the help of teamwork proved to be feasible. The practical improvements, however, were difficult to implement in the prevailing conditions. Some of the improvements increased the work load and the stress of the workers. This aspect needs further consideration.  相似文献   
26.
本文参阅国内外研究成果,对服装环境、服装材料、服装穿着与人体热舒适关系的有关问题进行了分析,认为热舒适对作业者的身心健康、对提高其工作效率有着重要意义。  相似文献   
27.
分析了在役生产装置安全评价存在的职业卫生问题,提出了如何做好重点生产装置职业病预防工作的建议。  相似文献   
28.
Comments on the original article, The dismantling of our health system: Strategies for the survival of psychological practice by Nicholas A. Cummings (see record 1986-22651-001). In response to this article, the current author says "no, no, no!" He believes that "survival with this degree of compromise amounts to doing anything for a buck." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
29.
对云计算技术实现医疗信息化的背景、研究基础、核心技术进行探讨,具体阐述了“健康云”在居民电子健康档案中的应用以及在医院信息管理系统中的应用,包括系统特点、整体架构等方面,并对其未来发展予以展望。  相似文献   
30.
Through an ergonomic approach, this study aimed to evaluate whether workers involved in forest harvesting activities in rural properties are subject to the development of work-related diseases, as well as their consequences. A cross-sectional study with 267 forest workers in rural properties in the Brazilian Central region was used. The following evaluations were performed for each of the activities (felling, delimbing, tracing, manual extraction and manual loading): physical workload evaluation; biomechanical evaluation; risk of repetitive strain injuries/work-related musculoskeletal disorders; environmental noise and vibration factors, where relevant, and thermal overload through the Wetbulb Globe Temperature index. The results showed that in general the physical workload was very high, exceeding the cardiovascular load limits and adding to the need for work reorganization. All activities exposed workers to serious and imminent risks of developing injuries to the spine and lower limbs. Likewise, in general the risk of the appearance of RSI/WMSDs was very high for all activities evaluated. Such results are due to the combination of organizational work factors and factors of the work environment such as exposure to bad weather, uneven terrain, lifting and handling loads above tolerable limits, excessive noise and thermal overload. All of this allows to conclude that ergonomic risks and workers’ health hazards in forest harvesting in rural properties are latent and very worrying, and that these workers are exposed to a form of labor exploitation that invariably leads to physical and emotional exhaustion and therefore to their decreased labor capacity and useful working life.  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