全文获取类型
收费全文 | 19780篇 |
免费 | 397篇 |
国内免费 | 1篇 |
专业分类
管理学 | 2608篇 |
民族学 | 111篇 |
人口学 | 1729篇 |
丛书文集 | 74篇 |
教育普及 | 1篇 |
理论方法论 | 1752篇 |
综合类 | 187篇 |
社会学 | 9954篇 |
统计学 | 3762篇 |
出版年
2023年 | 131篇 |
2022年 | 91篇 |
2021年 | 135篇 |
2020年 | 347篇 |
2019年 | 518篇 |
2018年 | 611篇 |
2017年 | 793篇 |
2016年 | 614篇 |
2015年 | 407篇 |
2014年 | 570篇 |
2013年 | 3524篇 |
2012年 | 734篇 |
2011年 | 683篇 |
2010年 | 500篇 |
2009年 | 403篇 |
2008年 | 532篇 |
2007年 | 487篇 |
2006年 | 522篇 |
2005年 | 407篇 |
2004年 | 419篇 |
2003年 | 350篇 |
2002年 | 367篇 |
2001年 | 469篇 |
2000年 | 412篇 |
1999年 | 403篇 |
1998年 | 313篇 |
1997年 | 262篇 |
1996年 | 278篇 |
1995年 | 290篇 |
1994年 | 247篇 |
1993年 | 258篇 |
1992年 | 300篇 |
1991年 | 294篇 |
1990年 | 289篇 |
1989年 | 255篇 |
1988年 | 239篇 |
1987年 | 201篇 |
1986年 | 229篇 |
1985年 | 250篇 |
1984年 | 217篇 |
1983年 | 191篇 |
1982年 | 161篇 |
1981年 | 130篇 |
1980年 | 155篇 |
1979年 | 172篇 |
1978年 | 134篇 |
1977年 | 114篇 |
1976年 | 91篇 |
1975年 | 91篇 |
1974年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
This work is based on the study of pioneering sustainable product development initiatives, and the analysis was guided by the cradle-to-cradle concept, which sees the waste of a given process as raw material for another, just like it happens in nature. Several studies on human factors have focused on factory conditions and workers dealing with product assembly. This research, however, relates more to consumer behavior, product use and end-of-life. The purchase of more environmentally- friendly products, in particular, is heavily influenced by the information made available by the companies. In this scenario, this article discusses three early but notable efforts on green product development, focusing on the disclosure practices adopted by the companies regarding the composition of their products. Research and data collection has focused on the footwear industry, whose products satisfy a basic human need and are ubiquitous worldwide. The use of hazardous materials and chemicals in shoe manufacturing, particularly the use of chromium - a highly toxic element - in addition to toxic solvents and adhesives and non-recyclable synthetic materials can pose serious risks to human health and the environment, even though the consumer usually is not aware of all the relevant characteristics of this kind of product. 相似文献
992.
Research activities to determine the need of recovery time at work were mainly performed in the 1970s and 1980s. Previous studies were largely based on expert opinions or were generated within small and non-representative groups. Often, laboratory experiments were carried out with a low number of subjects. Especially during the last decade, only little additional scientific knowledge was generated on this topic. The very resource intensive development of more detailed results based on the existing level of scientific knowledge is assumed as one reason for this. In general, it seems to be reasonable to continue further research on the knowledge generated in previous studies, but implement larger samples and more representative groups. Besides, according to monotonous manual work, more research is especially needed regarding relative operating forces and operation frequencies taken grip conditions and hand/body position into account. 相似文献
993.
This study aims to describe how anesthesia teams handle unforeseen events that may affect the patients' health. More precisely, it investigates the mechanisms of decisions made by anesthesia teams to manage unthought-of situations, i.e. situations that have not been foreseen as "possible" ones before their occurrence. An empirical study, based on the analysis of simulated situations, was conducted in a pediatric anesthesia service of a university hospital in France. The results highlighted three ways of managing unthought-of situations (determined management, cautious management and overwhelmed management). They support the hypothesis of a collective cognitive trade-off, whereby teams would behave as virtual operators, with their own collective trade-off between "understanding" and "doing". The discussion of the results questions the assessment criteria, the safety perspectives we adopt and the possible ways to improve the management of unforeseen situations. 相似文献
994.
995.
Gerontolinguistic obtains a growing importance with the increase of elderly users due to Demographic Change. Since acceptance and ease of use of supportive systems for elderly, such as "E-Nursing-Assistants", are highly dependent on the age suitable design of readable instructions, an age-appropriate linguistic concept is of high value for usability. There has been only little research on the relevance of foreign words, signal words, textual arrangement, optical accentuation of key terms and temporal iconicity concerning older users. Thus, an efficient design of age suitable manual instructions within a medical context still remains to be done. The objective of this research was to evaluate the relevance of the previously mentioned factors in the context of written instructions. For this, an empirical survey was designed which was given to 45 study participants. The subjects of the experiment were given 4x3 instructions after a pretest questionnaire. The aim was to execute these instructions as correctly and quickly as possible. Furthermore the instructions were rated regarding comprehensibility with a retrospective questionnaire. 相似文献
996.
This study presents the challenge involved in the negotiation and construction of a standard process in a major petroleum company that has the purpose of guiding the implementation of ergonomic studies in the development of projects, systemising the implementation of ergonomics design. The standard was created by a multi-disciplinary working group consisting of specialists in ergonomics, who work in a number of different areas of the company. The objective was to guide "how to" undertake ergonomics in all projects, taking into consideration the development of the ergonomic appraisals of work. It also established that all the process, in each project phase, should be accompanied by a specialist in ergonomics. This process as an innovation in the conception of projects in this company, signals a change of culture, and, for this reason requires broad dissemination throughout the several company leadership levels, and training of professionals in projects of ergonomics design. An implementation plan was also prepared and approved by the corporate governance, complementing the proposed challenge. In this way, this major oil company will implement new procedures of ergonomics design to promote health, safety, and wellbeing of the workforce, besides improving the performance and reliability of its systems and processes. 相似文献
997.
Comfort is an issue that has gained relevance within the aeronautical industry due to the necessity of manufacturers and airline companies of differentiating themselves in a market that has become more and more competitive each day. This study's aim is to analyze the comfort/discomfort of passengers, based on the analysis of the activities performed in the aircrafts' cabin during real flights, in order to create ergonomics requirements and a methodology of comfort analysis. The study has been performed during domestic commercial flights, and the adopted data collection techniques have been: the application of 219 questionnaires to passengers, 44 registrations of postures and actions through filmings and 12 semistructured interviews. The method has made possible the reconstruction of the user's action course in performing activities in real flight situations, and the calculation of the area occupied by the passenger during his or her actions. The integrated analysis of the results corroborates data from previous studies in which both the space made available to each passenger and the activity performed interfere in their perception of comfort. From this study it has been concluded that the method constitutes itself as an innovative tool within the process of aircrafts' cabins project enabling the calculation of the action space based on the reconstructed course. 相似文献
998.
Scott M. Fuess Jr. 《Journal of Family and Economic Issues》2012,33(2):250-260
Japan is famous for long working hours. For decades the Japanese government has tried to influence how people spend their free time. In 5-yearly surveys since 1986 the government has surveyed ??quality of life,?? gauging how much time people spend daily in various activities, including ??leisure.?? Analyzing results from these time use surveys, from 2006 back to 1986, and controlling for labor market conditions, this study determines whether time spent on leisure activities has actually changed. Gains in some types of leisure have been fleeting. Yet in other respects leisure has been enhanced, with significant increases occurring in active recreational pastimes. Nevertheless, leisure remains elusive for mid-career employees. Moreover, there is a pronounced gender gap for leisure time. 相似文献
999.
Johnson SM 《Journal of lesbian studies》2012,16(1):45-53
Research regarding lesbian mothers and their children has gone through a transformation in the last forty years. The first wave of research examined lesbians who had become parents while in heterosexual relationships. The second wave examined women who became parents within the context of lesbian relationships. Both of these waves focused on family functioning and child outcome, using heterosexual-headed families as comparison groups. The third wave of research, which is now underway, is focusing on the unique challenges faced by these families, and how lesbian mothers are creating and raising their families on their own terms. This article explores the research as it has evolved over the years and the direction in which it is headed. 相似文献
1000.
Alonso Ramírez Augustin Engman Keysa G. Rosas Omar Perez-Reyes Diana M. Martinó-Cardona 《Urban Ecosystems》2012,15(2):315-325
Improving our understanding of the impacts of urbanization on tropical island streams is critical as urbanization becomes a dominant feature in tropical areas. Although the ??urban stream syndrome?? has been successful in summarizing urban impacts on streams, the response of some island streams is different to that expected. Here we review available information on urban impacts to tropical island streams and describe unique responses to urbanization. We identified three key aspects that play particularly important or unique roles in determining tropical-island stream integrity: biotic response to water pollution, movement barriers along the stream network, and altered geomorphology that results in habitat loss. As expected, water pollution negatively impacts stream ecosystems in tropical islands and in some regions impacts can be severe, as untreated wastewaters are directly discharged into streams. While aquatic insects show the expected responses to pollution, other native fauna (e.g., shrimps and fishes) appear to be less impacted by moderate levels of pollution. Movement barriers along the stream network are especially important as much of the tropical island fauna have diadromous (either amphidromous or catadromous) life histories. Most native freshwater mollusks, shrimps, and fishes inhabiting tropical islands are diadromous and depend on unimpeded connections between freshwater and marine environments to complete their life cycles. The presence of these species in urban streams is best explained by longitudinal connectivity rather than by the degree of urban impact. Finally, in streams that remain connected to marine environments, the presence of native shrimps and fishes is strongly related to the physical habitat. Fish assemblages in channelized and severely altered stream reaches are almost completely devoid of native fauna and tend to be dominated by non-native species. In contrast, relatively diverse shrimp and fish assemblages can be found in reaches that retain their physical habitat complexity, even when they are impacted by urbanization. Our understanding of urban impacts on tropical island streams remains limited. However, the identification of key aspects can help us better understand urban impacts on streams in tropical islands, and best focus our management and research efforts to protect these unique ecosystems. 相似文献