全文获取类型
收费全文 | 17893篇 |
免费 | 305篇 |
专业分类
管理学 | 2438篇 |
民族学 | 82篇 |
人才学 | 3篇 |
人口学 | 1587篇 |
丛书文集 | 104篇 |
教育普及 | 2篇 |
理论方法论 | 1830篇 |
综合类 | 383篇 |
社会学 | 8902篇 |
统计学 | 2867篇 |
出版年
2021年 | 85篇 |
2020年 | 266篇 |
2019年 | 324篇 |
2018年 | 331篇 |
2017年 | 497篇 |
2016年 | 418篇 |
2015年 | 322篇 |
2014年 | 382篇 |
2013年 | 2921篇 |
2012年 | 542篇 |
2011年 | 466篇 |
2010年 | 336篇 |
2009年 | 368篇 |
2008年 | 410篇 |
2007年 | 436篇 |
2006年 | 363篇 |
2005年 | 494篇 |
2004年 | 449篇 |
2003年 | 417篇 |
2002年 | 441篇 |
2001年 | 449篇 |
2000年 | 405篇 |
1999年 | 422篇 |
1998年 | 304篇 |
1997年 | 292篇 |
1996年 | 293篇 |
1995年 | 270篇 |
1994年 | 284篇 |
1993年 | 268篇 |
1992年 | 298篇 |
1991年 | 309篇 |
1990年 | 269篇 |
1989年 | 271篇 |
1988年 | 258篇 |
1987年 | 232篇 |
1986年 | 234篇 |
1985年 | 231篇 |
1984年 | 262篇 |
1983年 | 249篇 |
1982年 | 218篇 |
1981年 | 183篇 |
1980年 | 178篇 |
1979年 | 209篇 |
1978年 | 177篇 |
1977年 | 161篇 |
1976年 | 143篇 |
1975年 | 140篇 |
1974年 | 125篇 |
1973年 | 120篇 |
1971年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
991.
Steven G. Rivkin Eric A. Hanushek John F. Kain 《Econometrica : journal of the Econometric Society》2005,73(2):417-458
This paper disentangles the impact of schools and teachers in influencing achievement with special attention given to the potential problems of omitted or mismeasured variables and of student and school selection. Unique matched panel data from the UTD Texas Schools Project permit the identification of teacher quality based on student performance along with the impact of specific, measured components of teachers and schools. Semiparametric lower bound estimates of the variance in teacher quality based entirely on within‐school heterogeneity indicate that teachers have powerful effects on reading and mathematics achievement, though little of the variation in teacher quality is explained by observable characteristics such as education or experience. The results suggest that the effects of a costly ten student reduction in class size are smaller than the benefit of moving one standard deviation up the teacher quality distribution, highlighting the importance of teacher effectiveness in the determination of school quality. 相似文献
992.
Narayana R. Kocherlakota 《Econometrica : journal of the Econometric Society》2005,73(5):1587-1621
In this paper, I consider a dynamic economy in which a government needs to finance a stochastic process of purchases. The agents in the economy are privately informed about their skills, which evolve stochastically over time; I impose no restriction on the stochastic evolution of skills. I construct a tax system that implements a symmetric constrained Pareto optimal allocation. The tax system is constrained to be linear in an agent's wealth, but can be arbitrarily nonlinear in his current and past labor incomes. I find that wealth taxes in a given period depend on the individual's labor income in that period and previous ones. However, in any period, the expectation of an agent's wealth tax rate in the following period is zero. As well, the government never collects any net revenue from wealth taxes. 相似文献
993.
994.
John Hendry† 《英国管理杂志》2005,16(S1):S55-S63
This paper argues that a consideration of some of the peculiarities of boards of directors can be used as a basis for developing and enriching our theoretical conception of agency relationships; and that the generalized version of agency theory that results can help us to better understand some of the empirical observations and theoretical and policy issues raised by Roberts, McNulty and Stiles. 相似文献
995.
996.
Brian R. Spisak Allen E. Grabo Richard D. Arvey Mark van Vugt 《The Leadership Quarterly》2014,25(5):805-816
The current contribution extends theorizing on leadership and the exploration–exploitation dilemma using an evolutionary perspective. A theoretical connection is made between the exploration–exploitation dilemma and age-biased leadership preferences for exploratory change versus stable exploitation. For the majority of human evolution our species was semi- or entirely nomadic and the trade-off between exploration versus exploitation had substantial physical- and experience-based requirements which align with leadership opportunities as moderated by age. Thus, given the consistency and importance of correctly assigning leadership for the exploration–exploitation dilemma, human evolution has likely selected for age-biased leadership endorsement. Across three experiments we find that younger-looking leaders are endorsed for times of exploratory change and older-looking leaders for stable exploitation. Further, our results indicated that older leaders are endorsed for leading conservative exploitation of nonrenewable resources and younger leaders for exploration of renewable alternatives (i.e., green leadership). The results introduce an age-biased leadership endorsement hypothesis. 相似文献
997.
Modern point‐of‐use technology at hospitals has enabled new replenishment policies for medical supplies. One of these new policies, which we call the hybrid policy, is currently in use at a large U.S. Midwest hospital. The hybrid policy combines a low‐cost periodic replenishment epoch with a high‐cost continuous replenishment option to avoid costly stockouts. We study this new hybrid policy under deterministic and stochastic demand. We develop a parameter search engine using simulation to optimize the long‐run average cost per unit time and, via a computational study, we provide insights on the benefits (reduction in cost, inventory, and number of replenishments) that hospitals may obtain by using the hybrid policy instead of the commonly used periodic policies. We also use the optimal hybrid policy parameters from the deterministic analysis to propose approximate expressions for the stochastic hybrid policy parameters that can be easily used by hospital management. 相似文献
998.
This article examines demand, manufacturing, and supply factors proposed to inhibit manufacturer delivery execution. Extant research proposes many factors expected to harm delivery performance. Prior cross‐sectional empirical research examines such factors at the plant level, generally finding factors arising from dynamic complexity to be significant, but factors arising from detail complexity to be insignificant. Little empirical research examines the factors using product‐level operating data, which arguably makes more sense for analyzing how supply chain complexity factors inhibit delivery. For purposes of research triangulation, we use longitudinal product‐level data from MRP systems to examine whether the factors inhibit internal manufacturing on time job rates and three customer‐oriented measures of delivery performance: product line item fill rates, average delivery lead times, and average tardiness. Our econometric models pool product line item data across division plants and within distinct product families, using a proprietary monthly dataset on over 100 product line items from the environmental controls manufacturing division of a Fortune 100 conglomerate. The data summarize customer ordering events of over 900 customers and supply chain activities of over 80 suppliers. The study contributes academically by finding significant detail complexity inhibitors of delivery that prior studies found insignificant. The findings demonstrate the need for empirical research using data disaggregated below the plant‐level unit of analysis, as they illustrate how some factors previously found insignificant indeed are significant when considered at the product‐level unit of analysis. Managers can use the findings to understand better which drivers and inhibitors of delivery performance are important. 相似文献
999.
This article examines the effect of product development restructuring (PDR) on shareholder value. The results are based on a sample of 165 announcements made during 2002–2011. PDR announcements are associated with an economically and statistically significant positive stock market reaction. Over a two‐day period (the day of the announcement and the day preceding the announcement), the mean (median) market reaction is 1.63% (0.87%). The market reaction is generally positive regardless of the PDR purpose or action. Although the market reaction is more positive for higher R&D intensity firms, it is not directly affected by the firm's prior financial performance or whether the firm's primary PDR objective is to increase revenues or cut costs. However, the interaction between the firm's prior financial performance and its primary PDR objective is significant. For firms that are financial outperformers, the market reaction is more positive if the firm's primary PDR objective is to increase revenues. For financial underperformers, the market reaction is more positive if the firm's primary PDR objective is to cut costs. 相似文献
1000.
This paper presents a theoretical model to help managers visualise and manage confidential situations more effectively. The model metaphorically likens a confidential setting to the properties of a soap bubble, e.g. elastic expansion or contraction, minimal surface area to contain a given volume, fragility, surface tension, pressure, stress, strain and the potential for bursting thereby releasing the contents to the external environment. We explore the conceptual developments in two phases. Firstly, looking at how a bubble and confidential scenario form and grow. Secondly, we consider how a bubble may burst and map these forces to ways in which confidentiality may be breached. Many attributes are mapped, the key ones being: the embedded value within the system, the criticality of maintaining confidentiality, increasing pressure, the corresponding stress/strain dynamics and the levels of trust between stakeholders. Key research propositions are derived from the model which aims to minimise the risk of a confidentiality breach. 相似文献