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   3426篇
  免费   141篇
管理学   398篇
民族学   51篇
人才学   1篇
人口学   385篇
丛书文集   5篇
理论方法论   318篇
综合类   76篇
社会学   1625篇
统计学   708篇
  2024年   4篇
  2023年   55篇
  2022年   44篇
  2021年   70篇
  2020年   153篇
  2019年   172篇
  2018年   273篇
  2017年   300篇
  2016年   234篇
  2015年   134篇
  2014年   173篇
  2013年   591篇
  2012年   268篇
  2011年   135篇
  2010年   117篇
  2009年   110篇
  2008年   105篇
  2007年   83篇
  2006年   75篇
  2005年   68篇
  2004年   51篇
  2003年   50篇
  2002年   43篇
  2001年   35篇
  2000年   21篇
  1999年   18篇
  1998年   20篇
  1997年   17篇
  1996年   21篇
  1995年   13篇
  1994年   14篇
  1993年   7篇
  1992年   12篇
  1991年   8篇
  1990年   8篇
  1989年   8篇
  1988年   7篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1984年   4篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1975年   3篇
  1974年   2篇
  1973年   4篇
  1971年   3篇
  1968年   2篇
  1967年   1篇
排序方式: 共有3567条查询结果,搜索用时 0 毫秒
991.
992.
With the advent of technology, the computer became a working tool increasingly present in companies. Its purpose is to increase production and reduce the inherent errors in manual production. The aim of this study was to analyze the usability of 2D graphics software in creating clothing designs by a professional during his work. The movements of the mouse, keyboard and graphical tools were monitored in real time by software Camtasia 7? installed on the user's computer. To register the use of mouse and keyboard we used auxiliary software called MouseMeter?, which quantifies the number of times they pressed the right, middle and left mouse's buttons, the keyboard and also the distance traveled in meters by the cursor on the screen. Data was collected in periods of 15 minutes, 1 hour and 8 hours, consecutively. The results showed that the job is considered repetitive and high demands physical efforts, which can lead to the appearance of repetitive strain injuries. Thus, the goal of minimizing operator efforts and thereby enhance the usability of the examined tool, becomes imperative to replace the mouse by a device called tablet, which also offers an electronic pen and a drawing platform for design development.  相似文献   
993.
This paper presents, illustrates and discusses a generic framework for studying knowledge co-elaboration in online epistemic communities ("OECs"). Our approach is characterised by: considering knowledge co-elaboration as a design activity; distinguishing discussion and production spaces in OECs; characterising participation via the notion of role; fine-grained analyses of meaning, content and communicative functions in interactions. On this basis, three key issues for ergonomics research on OECs are discussed and illustrated by results from our previous studies on OSS and Wikipedia. One issue concerns the interrelation between design (task) and regulation. Whereas design task-oriented activity is distributed among participants, we illustrate that OCEs function with specialised emerging roles of group regulation. However, the task-oriented activity also functions at an interpersonal level, as an interplay of knowledge-based discussion with negotiation of competencies. Another issue concerns the foci of activity on the (designed) knowledge object. Based on a generic task model, we illustrate asymmetry and distinctiveness in tasks' foci of participants. The last issue concerns how design-use mediation is ensured by specific forms of mediation roles in OECs. Finally we discuss the degree of generality of our framework and draw some perspectives for extending our framework to other OECs.  相似文献   
994.
In this paper, we present an original environment, the Distributed Collaborative Design Studio (DCDS) which allows multimodal real-time remote exchanges, and which aims at re-creating remotely the conditions of co-present meetings. This environment associates a videoconference tool (supporting verbal and non-verbal communication) and an original realtime shared digital hand-drawn sketches system (supporting graphical communication). The users can import documents and annotate them in real-time at distance. In this paper, we are interested in studying the use of the graphical modality (digital sketch and document annotations) as a tool for collective design and remote communication. This study takes place in the framework of a collaborative architectural design studio, which has taken place during 3 month, and gathering students from Belgium and France to work together in 3 small groups mainly at distance. The study focuses on the role of graphical modality in the synchronous remote meetings supported by the DCDS. We identify the types of digital annotations made on the imported document, thanks to the electronic pen, and their role in the cognitive processes of designing and in the collaboration and communication processes. We also identify the different practices of digital sketching, according to the group and its collaborative strategies. We discuss the utility of the graphical modality as an efficient support for collaborative synchronous activities and show that the DCDS environment supports different strategies of collaborative design (co-design and distributed design). We conclude on recommendations for improving the system and for designing sketch-based collaborative environments.  相似文献   
995.
Studies indicate that teachers constitute a professional segment, in which the work characteristics and the demands originating from the act of teaching, favor the emergence of sickness, concerning physical or emotional aspects. The present work aimed to describe physical and postural aspects during the working activity of teachers. A total of 120 elementary school teachers (1st to 8th grade) took part in the survey. For data collection, a questionnaire was applied: it included personal and occupational information, perception of discomfort and being off work; physical strength activities; posture at work and physical conditioning activities. The average age of teachers of the present sample corresponds to 35,8 years. In relation to activities which generate more physical strength, the answer none of the activities was predominant with 30 answers; followed by writing on the board, standing up during the period of classes, explanation of the subjects, class elaboration, correction of homework and others. The area of the body with higher amount of occurrences and prevalent discomfort referred to the lower limbs and spinal cord. These data inform the necessity of investing in prevention programs for the teachers, in order to develop strategies into the organizational context and interventions at the work environment.  相似文献   
996.
Comfort on automobile seats is lived daily by thousands of drivers. Epistemologically, comfort can be understood under the theory of complexity, since it emerges from a chain of interrelationships between man and several elements of the system. This interaction process can engender extreme comfort associated to the feeling of pleasure and wellbeing or, on the other hand, lead to discomfort, normally followed by pain. This article has for purpose the development of a theoretical model that favours the comfort feature on automobile seats through the identification of its facets and indicators. For such, a theoretical study is resorted to, allowing the mapping of elements that constitute the model. The results present a comfort model on automobile seats that contemplates the (physical, psychological, object, context and environment) facets. This model is expected to contribute with the automobile industry for the development of improvements of the ergonomic project of seats to increase the comfort noticed by the users.  相似文献   
997.
998.
The use of boiler wood-fired is fairly common equipment utilized in steam generation for energy production in small industries. The boiler activities are considered dangerous and heavy, mainly due to risks of explosions and the lack of mechanization of the process. This study assessed the burden of physical labor that operators of boilers are subjected during the workday. Assessment of these conditions was carried out through quantitative and qualitative measurements. A heart rate monitor, a wet-bulb globe thermometer (WBGT), a tape-measure and a digital infrared camera were the instruments used to collect the quantitative data. The Nordic Questionnaire and the Painful Areas Diagram were used to relate the health problems of the boiler operator with activity. With study, was concluded that the boiler activity may cause pains in the body of intensity different, muscle fatigue and diseases due to excessive weight and the exposure to heat. The research contributed to improve the boiler operator's workplace and working conditions.  相似文献   
999.
The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload.  相似文献   
1000.
Unexpected sudden (un)loading of the trunk may induce inadequate responses of trunk muscles and uncontrolled trunk motion. These unexpected perturbations may occur in pushing tasks, when the cart suddenly starts moving (unloading) or is blocked by an obstacle (loading). In pushing, handle height affects the user's working posture, which may influence trunk muscle activity and trunk movement in response to the perturbation. Eleven healthy male subjects pushed a 200 kg cart with handles at shoulder and hip height in a start condition (sudden release of brakes) and a stop condition (bumping into an obstacle). Before the perturbation, the baseline of the trunk inclination, internal moment and trunk extensor muscle activity were significantly higher when pushing at hip height than at shoulder height. After the perturbation, the changes in trunk inclination and internal moment were significantly larger when pushing at shoulder height than at hip height in both conditions. The opposite directions of changes in trunk inclination and internal moment suggest that the unexpected perturbations caused uncontrolled trunk motion. Pushing at shoulder height may impose a high risk of low-back injury due to the low trunk stiffness and large involuntary trunk motion occurring after carts suddenly move or stop.  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