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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   8228篇
  免费   20篇
管理学   1273篇
民族学   27篇
人口学   766篇
丛书文集   26篇
理论方法论   594篇
综合类   105篇
社会学   3402篇
统计学   2055篇
  2021年   45篇
  2020年   129篇
  2019年   168篇
  2018年   217篇
  2017年   273篇
  2016年   198篇
  2015年   138篇
  2014年   198篇
  2013年   1320篇
  2012年   263篇
  2011年   253篇
  2010年   185篇
  2009年   178篇
  2008年   148篇
  2007年   185篇
  2006年   161篇
  2005年   161篇
  2004年   148篇
  2003年   144篇
  2002年   149篇
  2001年   197篇
  2000年   190篇
  1999年   172篇
  1998年   130篇
  1997年   127篇
  1996年   127篇
  1995年   109篇
  1994年   104篇
  1993年   100篇
  1992年   144篇
  1991年   123篇
  1990年   119篇
  1989年   111篇
  1988年   96篇
  1987年   93篇
  1986年   98篇
  1985年   108篇
  1984年   112篇
  1983年   123篇
  1982年   100篇
  1981年   88篇
  1980年   85篇
  1979年   94篇
  1978年   90篇
  1977年   80篇
  1976年   67篇
  1975年   67篇
  1974年   58篇
  1973年   58篇
  1971年   49篇
排序方式: 共有8248条查询结果,搜索用时 11 毫秒
221.
222.
Application of Executive Order 12898 to risk assessment of highway or rail transport of hazardous materials has proven difficult; in general, the location and conditions affecting the propagation of a plume of hazardous material released in a potential accident are unknown. Therefore, analyses have only been possible in a geographically broad or approximate manner. The advent of geographic information systems and development of software enhancements at Sandia National Laboratories have made kilometer-by-kilometer analysis of populations tallied by U.S. Census blocks along entire routes practicable. Tabulations of total or racially/ethnically distinct populations close to a route, its alternatives, or the broader surrounding area, can then be compared and differences evaluated statistically. This article presents methods of comparing populations and their racial/ethnic compositions using simple tabulations, histograms, and chi-square tests for statistical significance of differences found. Two examples of these methods are presented: comparison of two routes and comparison of a route with its surroundings.  相似文献   
223.
The simplified Conjoint Expected Risk (CER) model by Holtgrave and Weber posits that perceived risk is a linear combination of the subjective judgments of the probabilities of harm, benefit, and status quo, and the expected harm and benefit of an activity. It modifies Luce and Weber's original CER model—that uses objective information to evaluate financial gambles—to accommodate activities such as health/technology activities where values of the model variables are subjective. If the simplified model is a valid modification of the original model, its performance should not be sensitive to the use of subjective information. However, because people may evaluate information differently when objective information is provided to them than when they generate information on their own, the performance of the simplified CER model may not be robust to the source of model-variable information. We compared the use of objective and subjective information, and results indicate that the estimates of the simplified CER model parameters and the proportion of variance in risk judgments accounted for by the model are similar under these two conditions. Thus, the simplified CER model is viable with activities for which harm and benefit information is subjective.  相似文献   
224.
Many optimisation problems arise in managing the Blood Donation (BD) supply chain. Most of them have been addressed in the literature, while other problems, e.g. donation scheduling, have not been sufficiently addressed so far. However, blood collection from donors may have a disruptive impact on the entire BD supply chain if not properly managed. For example, scheduling donation appointments based on some system metrics may improve the flow of blood units through the BD supply chain and increase the quality of service perceived by donors. In this short communication, we present the donation scheduling problem and highlight the lack of work in the literature that deals with this problem. Then, we analyse the impact of an unbalanced flow of blood units on the BD system and the benefits that may derive from a suitable appointment scheduling. Finally, we propose suggestions for future research in BD collection scheduling that may improve the BD process.  相似文献   
225.
Retraining of staff is a compulsory managerial function in many organisations and often requires planning for a large number of employees. The large scale of this problem and various restrictions on the resultant assignment to classes make this planning challenging. The paper presents a complexity analysis of this problem together with linear and nonlinear mathematical programming formulations. Three different column generation based optimisation procedures and a large neighbourhood search procedure, incorporating column generation, are compared by means of computational experiments. The experiments used data typical to large electricity distributors.  相似文献   
226.
The leadership tendencies of people are likely to be influenced by their cultural contexts. For example, it is expected that people from high-context cultures are likely to be more focused on relationships. To explore the behavioral tendencies of working adults in the cities of Tehran and Kerman, this pilot study focused on comparing the leadership and stress perceptions of 228 Iranian respondents based on their age and gender. These respondents have a significantly higher score on relationship orientation. On the other side, the younger respondents from Iran had a significantly higher score on the stress overload perception. Practical suggestions for expatriates and implications for future studies are presented.  相似文献   
227.
Constructive-developmental theory is a stage theory of adult development that focuses on the growth and elaboration of a person's ways of understanding the self and the world. In this article we review how the constructive-developmental frameworks of Kegan [Kegan, R. (1982). The evolving self: Problem and process in human development. Cambridge, MA: Harvard University Press], Torbert [Torbert, W. R. (1987). Managing the corporate dream: Restructuring for long-term success. Homewood, IL: Dow Jones-Irwin.], and Kohlberg [Kohlberg, L. (1969). Stage and sequence: The cognitive developmental approach to socialization. In D. Goslin (Ed.), Handbook of socialization: Theory and research. New York: Rand McNally] have been applied in the theoretical and empirical literature on leadership and management. Although the literature has produced a number of propositions, the notion that a leader's order of development should impact his or her leadership effectiveness or managerial performance has generated the most research. We found mixed support for this proposition as well as a number of limitations in the research in general. To have a greater impact on the leadership field, constructive-developmental theory needs to generate more robust research, to link more clearly with on-going streams of leadership research, and to explore the contribution of aspects of the theory beyond individual order of development.  相似文献   
228.
This paper presents findings of a survey on manufacturing strategy practices adopted by the Indian machinery manufacturing companies (IMMC). Based on the survey, three companies have been selected for detailed case studies. Their experiences in the manufacturing strategy process are analyzed. Although the companies represented diversity in terms of product type, sales volume, and geographic location, they share several commonalties including use of advanced manufacturing technologies and use of several improvement techniques. The process of strategy formulation varied among the companies in terms of participants, complexity and degree of formalization. Competitive priorities, order winners and critical success factors are also identified for these companies. Based on strategic manufacturing issues, manufacturing competence index and business performance index for the companies has been worked out.  相似文献   
229.
互补品天才     
Nicholas G.Carr 《经理人》2007,(3):80-80,82
安德烈和爱德华当初是怎么想的? 1900年,就在两兄弟刚刚接管家族设在克莱蒙一费朗市橡胶生意之后不久,他们决定为旅行者出版一本指导手册。在他们的《米其林指南》一书当中,作者提供了大量加油站、酒店、餐厅和观光景点的信息,并配有详尽的地图和旅行提示。该书第一版印刷了35000册,米其林公司免费将其发放给那些感兴趣的读者们。他们的这一做法后来被证明是一个极其天才的举动。  相似文献   
230.
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