全文获取类型
收费全文 | 19649篇 |
免费 | 536篇 |
国内免费 | 3篇 |
专业分类
管理学 | 2760篇 |
民族学 | 99篇 |
人才学 | 3篇 |
人口学 | 1707篇 |
丛书文集 | 104篇 |
理论方法论 | 1901篇 |
综合类 | 367篇 |
社会学 | 9596篇 |
统计学 | 3651篇 |
出版年
2020年 | 288篇 |
2019年 | 457篇 |
2018年 | 450篇 |
2017年 | 663篇 |
2016年 | 465篇 |
2015年 | 385篇 |
2014年 | 478篇 |
2013年 | 3389篇 |
2012年 | 637篇 |
2011年 | 579篇 |
2010年 | 495篇 |
2009年 | 449篇 |
2008年 | 515篇 |
2007年 | 543篇 |
2006年 | 474篇 |
2005年 | 456篇 |
2004年 | 411篇 |
2003年 | 337篇 |
2002年 | 387篇 |
2001年 | 481篇 |
2000年 | 410篇 |
1999年 | 381篇 |
1998年 | 317篇 |
1997年 | 309篇 |
1996年 | 285篇 |
1995年 | 270篇 |
1994年 | 252篇 |
1993年 | 276篇 |
1992年 | 292篇 |
1991年 | 277篇 |
1990年 | 289篇 |
1989年 | 252篇 |
1988年 | 250篇 |
1987年 | 264篇 |
1986年 | 226篇 |
1985年 | 237篇 |
1984年 | 275篇 |
1983年 | 245篇 |
1982年 | 222篇 |
1981年 | 169篇 |
1980年 | 204篇 |
1979年 | 222篇 |
1978年 | 177篇 |
1977年 | 164篇 |
1976年 | 159篇 |
1975年 | 183篇 |
1974年 | 161篇 |
1973年 | 121篇 |
1972年 | 116篇 |
1971年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
991.
Stephen E. Bechtold 《决策科学》1988,19(2):353-372
This paper presents a tractable set of integer programming models for the days-off scheduling of a mix of full- and part-time employees working α to β days/week (cycle) in a multiple-objective, multiple-location environment. Previous models were formulated to specifically schedule part-time employees working either two or three days per week. These models were intractable because they required complete employee schedule information. The new models are deemed implicit optimal since they are required to supply only essential information. While the number of variables in previous models is an exponential increasing function of β-α, the size of three of the new models is independent of α and β. The first three models developed here (as in [18]) deal with the trade-offs between idle time, the number of employees required to work at multiple “locations,” and the size of the total labor pool. The inherent flexibility of the implicit modeling approach is illustrated by the presentation of various modifications of the basic models. These modifications permit the use of preference weights on the number of employee work days/week (cycle) or the minimization of payroll costs where differential pay rates exist. These latter models may also be formulated such that idle time is ignored, constrained or minimized. The execution time for the implicit models (on a CDC CYBER 730 computer with commercially available software) averaged well under five seconds on 1200 trial problems for the type of application considered in [18]. A solution was obtained in less than 46 seconds of CPU time for a trial problem which would have required over 1.4 million integer variables with previous models. The availability of optimal solutions was invaluable in the development of two heuristics designed to deal with the trade-offs of [16]. In an experimental analysis a previous heuristic produced results which averaged from 74 to 508 percent above optimum across six experimental conditions. The comparable new heuristic produced results which averaged from 3 to 8 percent above optimum for the same experimental conditions. The paper concludes by developing a framework to integrate the results of this research with the tour scheduling problem and by identifying several other areas for related research. 相似文献
992.
H.W. Singer 《Development policy review : the journal of the Overseas Development Institute》1988,6(1):75-84
Book reviewed in this article: Foreign Aid Reconsidered. By Roger C. Riddell. Overseas Aid: Its Defence and Reform. By Paul Mosley. Missed Opportunities: Britain and the Third World. By Charles Elliott et al. 相似文献
993.
Social Indicators Research - This paper investigates the relationship between economic adversity and voter participation in Turkish parliamentary elections. We employ a dynamic model of voter... 相似文献
994.
This paper proposes an interpretation of the pure capital rationing problem as it is faced by many managers in decentralized firms in which budgets serve as the principal means of control. It is argued that the appropriate objective for situations such as these is the maximization of either undiscounted earnings over the planning horizon or total value of the investments at the horizon. When either objective function is used in conjunction with the frequently encountered linear programming models for the capital rationing problem, shadow prices result which give rise to discount rates that will reproduce the optimal solution using discounted cash flow as a criterion. These results are then used as a means for clarifying several confusing and misleading statements that have appeared in the literature. 相似文献
995.
The purpose of the current study was to determine whether brand name can affect the public's evaluation of a product. All subjects smoked identical cigarettes. One group of subjects, however, knew the cigarettes by the name of “Frontiersman,” a masculine name, while the other group knew the cigarettes as “April,” a feminine name. Male and female subjects were asked to rate the cigarette on seven measures. Results show that women gave a more positive evaluation to the cigarette purportedly named “April,” while men gave a more positive evaluation to the identical cigarette when they thought it was named “Frontiersman.” In addition, women reacted more strongly than did men to brand name influence. 相似文献
996.
997.
The UN Convention on the Rights of the Child mandates (Articles 19 and 20) that alternative care be available to protect children from maltreatment by parents and caregivers. Increasingly, countries around the world have recognized the benefits to child well-being of family-based care as an alternative to institutional care. The special if not extraordinary needs of children separated from parents because of abuse, neglect, and maltreatment and placed with foster families requires a commensurate effort to develop foster families who have special if not extraordinary skills. Methods that are effective and replicable across countries offer significant advantages, reducing investments in policies and practices that otherwise would have to be developed independently, country by country. This case study describes the factors that contributed to the transfer of knowledge in the assessment, selection, and training of foster parents and the impact to date. 相似文献
998.
999.
Prof. Dr. Helmut E. Lück 《Gruppendynamik und Organisationsberatung》2009,40(1):102-114
It is shown that the concept of ?Hawthorne effect‘ was created many years after the Hawthorne studies in Western Electric Company. Presently, the ?Hawthorne effect‘ concept is increasingly used in social sciences and many other sciences. The concept is however used in different and occasionally digressive meanings. The question arises whether such a concept is useful at all. In addition, it is discussed why the rather imprecise reports of single Hawthorne field experiments have been spread as academic folklore, and why rather undefined concepts like the ?Hawthorne effect‘ are used so widely in psychology and social sciences. 相似文献
1000.
In this paper, we investigate the determinants of corporate reputation, derived from the assessments of managers and market analysts, of a sample of large UK firms. Along with the influences of a variety of firm attributes, we find a reputational effect associated with a female presence at board level. This effect varies across sectors and demonstrates the influence of a firm's stakeholder environment in determining whether a female presence on the board enhances or harms the reputation of the firm. The pattern that emerges indicates that the presence of women on the board is favourably viewed in only those sectors that operate close to final consumers. We argue that the nature of this effect reflects an imperative for equality of representation that highlights the need to reflect gender diversity among customers. 相似文献