全文获取类型
收费全文 | 6421篇 |
免费 | 53篇 |
国内免费 | 1篇 |
专业分类
管理学 | 231篇 |
民族学 | 173篇 |
人才学 | 15篇 |
人口学 | 371篇 |
丛书文集 | 255篇 |
教育普及 | 3篇 |
理论方法论 | 3226篇 |
综合类 | 855篇 |
社会学 | 1168篇 |
统计学 | 178篇 |
出版年
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 11篇 |
2019年 | 25篇 |
2018年 | 16篇 |
2017年 | 22篇 |
2016年 | 17篇 |
2015年 | 25篇 |
2014年 | 86篇 |
2013年 | 30篇 |
2012年 | 381篇 |
2011年 | 257篇 |
2010年 | 135篇 |
2009年 | 97篇 |
2008年 | 154篇 |
2007年 | 210篇 |
2006年 | 213篇 |
2005年 | 178篇 |
2004年 | 162篇 |
2003年 | 136篇 |
2002年 | 137篇 |
2001年 | 153篇 |
2000年 | 144篇 |
1999年 | 65篇 |
1998年 | 60篇 |
1997年 | 37篇 |
1996年 | 43篇 |
1995年 | 54篇 |
1994年 | 42篇 |
1993年 | 181篇 |
1992年 | 232篇 |
1991年 | 293篇 |
1990年 | 118篇 |
1989年 | 218篇 |
1988年 | 216篇 |
1987年 | 226篇 |
1986年 | 250篇 |
1985年 | 270篇 |
1984年 | 269篇 |
1983年 | 268篇 |
1982年 | 307篇 |
1981年 | 349篇 |
1980年 | 232篇 |
1979年 | 46篇 |
1978年 | 16篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1967年 | 6篇 |
1959年 | 8篇 |
1957年 | 9篇 |
排序方式: 共有6475条查询结果,搜索用时 765 毫秒
261.
Performance of certain cognitive tasks either during physical load or in rest pauses between boosts might lead to slowing of muscle fatigue and fatigue related decline in performance. Seventeen right-handed healthy volunteers (age 24 ± 1.4, 8 males) participated in this study, aiming to investigate the effect of the level of the cognitive information processing - 1) passive perception of audio stimuli, 2) active stimuli discrimination, 3) active stimuli discrimination following motor response - on motor task performance (handgrip test 30% and 7% of MVC) and muscle fatigue development. Cognitive tasks show the following effects on motor work: i) Perceived fatigue during 30 % MVC (fatiguing) condition developed slower if participant pressed button in response to deviant acoustic stimuli, as compared to passive listening. Counting task, an active task without motor component, took the intermediate position and did not differ significantly from two other cognitive tasks. ii) MVC after 30% MVC (fatiguing) condition tended to decrease stronger when accompanied with passive listening in comparison with both active tasks. iii) Motor task performance during 30% MVC (fatiguing) condition was better for active cognitive task with motor component than for passive task. Active task without motor component took the intermediate position and did not differ significantly from both the other cognitive tasks. 相似文献
262.
Healthcare workers, namely registered nurses (RN), are frequently exposed to work-related musculoskeletal disorders (WRMSDs) risk factors. Identifying the symptoms of these disorders is one of the first epidemiological steps to managing them. This study aims to identify WRMSDs prevalence symptoms in Portuguese RN. During 8 months (2010-2011) the National Public Health School and the Portuguese Registered Nurses Board made a call to all RN to answer an online WRMSDs questionnaire. Respondents (n=2140) are mostly females (77.4%) and work mainly in hospitals (n=1396) and in primary healthcare centers (n=421). Results show high symptoms prevalence (last 12 months) in the lower back (60.6%), the upper back (44.5%), and the neck (48.6%). Nurses' activity, especially patient hygiene in bed, is a strong contributor (p>0.05) to pain in the upper back (OR=1.39 [1.09-1.80]) and lower back (OR=1.4 [1.08-1.84]). Patient holdup without mechanical support has the highest relationship (p>0.05) between work tasks and symptoms in the last 12 months in the upper back (OR=1.50 [1.19-1.90]). Prevalence rates of WRMSDs symptoms in Portuguese nurses are no different from other studies with Swedish, Italian and Greek nurses. Maybe changes in healthcare systems didn't change the way care is delivered and we must rethink how to prevent nurses WRMSDs. 相似文献
263.
Andersen JH Frost P Fuglsang-Frederiksen A Johnson B Wulff Svendsen S 《Work (Reading, Mass.)》2012,41(Z1):2434-2437
We aimed to evaluate associations between vocational computer use and 1) ulnar neuropathy, and 2) ulnar neuropathy- like symptoms as distinguished by electroneurography. We identified all patients aged 18-65 years, examined at the Department of Neurophysiology on suspicion of ulnar neuropathy, 2001-2007. We mailed a questionnaire to 546 patients with ulnar neuropathy, 633 patients with ulnar neuropathy-like symptoms, and three community referents per case, matched on sex, age, and primary care centre. From a Job Exposure Matrix we extracted estimates of daily hours of computer use. The analysis was performed by conditional logistic regression.There were a negative association between daily hours of computer use and the two outcomes of interest. Participants who reported their elbow to be in contact with their working table for 2 hours or more during the workday had an elevated risk for ulnar neuropathy (OR=2.16, 95 % CI; 1.06-4.44).The two outcomes were not associated with daily hours of computer use. Findings suggested specific effects of pressure on the elbow, and might be an explanation for the overweight of left-sided outcomes in this primarily right-handed group. Preventive efforts would then be straightforward by providing appropriate arm support for the left arm and elbow. 相似文献
264.
Upper extremity musculoskeletal symptoms and disorders are common in the working population. The economic and social impact of such disorders is considerable. Long-time, dynamic repetitive exposure of the hand-arm system during manual handling operations (MHO) alone or in combination with static and postural effort are recognised as causes of musculoskeletal symptoms and disorders. The assessment of these manual work tasks is crucial to estimate health risks of exposed employees. For these work tasks, a new method for the assessment of the working conditions was developed and a validation study was performed. The results suggest satisfying criterion validity and moderate objectivity of the KIM-MHO draft 2007. The method was modified and evaluated again. It is planned to release a new version of KIM-MHO in spring 2012. 相似文献
265.
266.
Lüdtke A Javaux D Tango F Heers R Bengler K Ronfle-Nadaud C 《Work (Reading, Mass.)》2012,41(Z1):4250-4257
The paper presents a new approach to the development of cooperative human-machine systems in the Transportation domain which is currently researched in the European project D3CoS. A necessary precondition for the acceptance of cooperative human-machine systems with shared control is the confidence and trust of the user into the system. D3CoS tackles this important issue by addressing the cooperative system as the object and the target of the system development process. This new perspective, along with corresponding innovative methods, techniques and tools, shall allow the identification of optimal task and authority sharing approaches supported by intuitive human-machine interaction and user interfaces at an early stage of system development. This will support powerful teamwork between humans and machines or between machines and machines that is transparent, intuitive and easy to understand. The paper describes the research dimensions for the development of the methods, techniques and tools as well as first results. 相似文献
267.
268.
Lately, with the goal of improving road safety, car makers developed and commercialised some Advanced Driver Assistance Systems (ADAS) which, through the detection of blind spot areas on the vehicle's sides, could help the drivers during the overtaking and the change lane task. Despite the possible benefits to reduce lateral crashes, the overall impact on road safety of such systems have not been deeply studied yet; notably, despite some researches have been carried out, there is a lack of studies regarding the long-term usage and drivers' acceptance of those systems. In order to fill the research gap, a methodology, based on the combination of focus groups interviews, questionnaires and a small-scale field operational test (FOT), has been designed in this study; such a methodology aims at evaluating drivers' acceptance of Blind Spot Information System? and at proposing some ideas to improve the usability and user-friendliness of this (or similar) device in their future development. 相似文献
269.
Ergonomics and accessibility in banking has been the subject of numerous discussions, and in this work proposed by the partnership of companies and NR TN Mobile Work Safety and Occupational Medicine, aimed to analyze the service box and propose the development of a project to the teller accessible account of both the legal aspects regarding the factors inherent in banking, focusing primarily on the interface of the worker and the client user. 相似文献
270.
Carpal tunnel syndrome is one of the most costly upper extremity disorders in the working population. Past literature has shown an association between personal and work factors to a case definition of carpal tunnel syndrome but little is known about the combined effects of these factors with the development of this disorder. Few studies have examined these associations in longitudinal studies. The purpose of this paper is to identify risk factors for incident carpal tunnel syndrome in a longitudinal study of workers across a wide range of occupations. 相似文献