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   1575篇
  免费   41篇
  国内免费   10篇
管理学   275篇
民族学   15篇
人口学   197篇
丛书文集   11篇
理论方法论   123篇
综合类   48篇
社会学   556篇
统计学   401篇
  2023年   15篇
  2022年   16篇
  2021年   12篇
  2020年   35篇
  2019年   43篇
  2018年   47篇
  2017年   81篇
  2016年   49篇
  2015年   33篇
  2014年   42篇
  2013年   315篇
  2012年   62篇
  2011年   58篇
  2010年   32篇
  2009年   33篇
  2008年   39篇
  2007年   45篇
  2006年   33篇
  2005年   48篇
  2004年   38篇
  2003年   24篇
  2002年   28篇
  2001年   47篇
  2000年   31篇
  1999年   30篇
  1998年   21篇
  1997年   22篇
  1996年   22篇
  1995年   15篇
  1994年   22篇
  1993年   18篇
  1992年   16篇
  1991年   9篇
  1990年   14篇
  1989年   23篇
  1988年   21篇
  1987年   17篇
  1986年   17篇
  1985年   23篇
  1984年   17篇
  1983年   18篇
  1982年   17篇
  1981年   20篇
  1980年   12篇
  1979年   4篇
  1978年   4篇
  1977年   4篇
  1976年   7篇
  1973年   6篇
  1972年   4篇
排序方式: 共有1626条查询结果,搜索用时 15 毫秒
101.
Open innovation and absorptive capacity are two concepts based on the idea that companies can leverage the knowledge generated externally to improve their innovation performance. The aim of this paper is to analyse the joint effect of open innovation and absorptive capacity on a firm's radical innovation. Open innovation is expressed in terms of external search breadth and depth strategies and absorptive capacity is described by distinguishing between potential and realized absorptive capacity. In order to test our hypotheses, we carried out empirical research in firms operating in high-technology industries. The results indicate that internal routines and processes for absorbing external knowledge help explain radical innovation as they show a significant effect of potential and realized absorptive capacity. Also, there is a moderating effect of absorptive capacity on open innovation. Specifically, potential absorptive capacity exerts a positive effect on the relationship between external search breadth and depth and radical innovation. Realized absorptive capacity moderates the influence of external search breadth. These findings confirm the complementary nature of absorptive capacity and open innovation search strategies on radical innovation.  相似文献   
102.
Consider the problem of partitioning n nonnegative numbers into p parts, where part i can be assigned ni numbers with ni lying in a given range. The goal is to maximize a Schur convex function F whose ith argument is the sum of numbers assigned to part i. The shape of a partition is the vector consisting of the sizes of its parts, further, a shape (without referring to a particular partition) is a vector of nonnegative integers (n1,..., np) which sum to n. A partition is called size-consecutive if there is a ranking of the parts which is consistent with their sizes, and all elements in a higher-ranked part exceed all elements in the lower-ranked part. We demonstrate that one can restrict attention to size-consecutive partitions with shapes that are nonmajorized, we study these shapes, bound their numbers and develop algorithms to enumerate them. Our study extends the analysis of a previous paper by Hwang and Rothblum which discussed the above problem assuming the existence of a majorizing shape. This research is partially supported by ROC National Science grant NSC 92-2115-M-009-014.  相似文献   
103.
Risk Modeling, Assessment, and Management of Lahar Flow Threat   总被引:1,自引:0,他引:1  
The 1991 eruption of Mount Pinatubo in the Philippines is considered one of the most violent and destructive volcanic activities in the 20th century. Lahar is the Indonesian term for volcanic ash, and lahar flows resulting from the massive amount of volcanic materials deposited on the mountain's slope posed continued post-eruption threats to the surrounding areas, destroying lives, homes, agricultural products, and infrastructures. Risks of lahar flows were identified immediately after the eruption, with scientific data provided by the Philippine Institute of Volcanology, the U.S. Geological Survey, and other research institutions. However, competing political, economic, and social agendas subordinated the importance of scientific information to policy making. Using systemic risk analysis and management, this article addresses the issues of multiple objectives and the effective integration of scientific techniques into the decision-making process. It provides a modeling framework for identifying, prioritizing, and evaluating policies for managing risk. The major considerations are: (1) applying a holistic approach to risk analysis through hierarchical holographic modeling, (2) applying statistical methods to gain insight into the problem of uncertainty in risk assessment, (3) using multiobjective trade-off analysis to address the issue of multiple decisionmakers and stakeholders in the decision-making process, (4) using the conditional expected value of extreme events to complement and supplement the expected value in quantifying risk, and (5) assessing the impacts of multistage decisions. Numerical examples based on ex post data are formulated to illustrate applications to various problems. The resulting framework from this study can serve as a general baseline model for assessing and managing risks of natural disasters, which the Philippines' lead agency-the National Disaster Coordinating Council (NDCC)-and other related organizations can use for their decision-making processes.  相似文献   
104.
Many analyses for incomplete longitudinal data are directed to examining the impact of covariates on the marginal mean responses. We consider the setting in which longitudinal responses are collected from individuals nested within clusters. We discuss methods for assessing covariate effects on the mean and association parameters when covariates are incompletely observed. Weighted first and second order estimating equations are constructed to obtain consistent estimates of mean and association parameters when covariates are missing at random. Empirical studies demonstrate that estimators from the proposed method have negligible finite sample biases in moderate samples. An application to the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) demonstrates the utility of the proposed method.  相似文献   
105.
We establish a reflection principle for three lattice walkers and use this principle to reduce the enumeration of configurations of three vicious walkers to the enumeration of configurations of two vicious walkers. More precisely, the reflection principle leads to a bijection between three walks (L1, L2, L3) such that L2 intersects both L1 and L3 and three walks (L1, L2, L3) such that L1 intersects L3. Hence we find a combinatorial interpretation of the formula for the generating function for the number of configurations of three vicious walkers, originally derived by Bousquet-Mélou by using the kernel method, and independently by Gessel by using tableaux and symmetric functions. This answers a question posed by Gessel and Bousquet-Mélou. We also find a reflection principle for four vicious walks that leads to a combinatorial interpretation of a formula derived from Gessel's theorem.  相似文献   
106.
107.
All that is known about strategy and strategic planning indicates that quality is a major factor in gaining competitive advantage. It is cost effective, profitable, promotes corporate longevity and builds an important company value system. The authors argue that is too important a factor to be left solely to quality control personnel or planners and is a fundamental part of the chief executive's responsibility for the development of strategy.  相似文献   
108.
The authors examined factors influencing the return rates for attempting to collect active parental consent forms from 21,123 students in the 7th through 10th grades in 41 middle and high schools. Overall return rates from middle schools were higher than from high schools. Schools that offered high levels of staff support for collecting consent forms had higher return rates. Procedures where the consent form was attached to a school form that parents had to complete and return to the school yielded the highest return rate. Implications for how researchers can obtain a high parent consent form return rate are discussed.  相似文献   
109.
Past studies on the effects of sexually explicit materials on women have tended to study them alone, in pairs, or in groups of strangers. By contrast, our study randomly assigned women to bring either a same-sex friend or a male partner to reflect more natural viewing conditions. Discussion between the participant and her companion followed exposure to the sexual images. Women who viewed pornography maintained their (quite high) level of negative mood, whereas women who viewed erotica experienced a substantial improvement in mood. The sex of the companion did not have a direct influence on participants' mood, with discussion improving mood across the board. However, participants' ratings of their satisfaction with the discussion were significantly influenced by the sex of their companion. We suggest that future research should focus more on the interpersonal aspects of male-female relationships when exploring the effects of sexually explicit materials on heterosexual women.  相似文献   
110.
The lack of vocational rehabilitation in Iceland inspired the Janus Rehabilitation initiative in the year 2000. The team currently consists of two occupational therapists, a social worker, a physiotherapist, a psychologist, and a physician. Janus uses resources from local education establishments and is located at the Reykjavík Technical School. A client-centred approach is used, enabling a flexible rehabilitation timeframe. The aim is to help the client back to employment/education. Advantage is taken of the facilities of the school where integration between education and rehabilitation takes place. Forty individuals have been admitted, with a mean time from work of 2.9 years, (range: 0-11 years). Seventeen (43%) have returned to employment/education. Twenty-three of those entering the programme are still on invalidity pension. The Canadian Occupational Performance Measurement (COPM) shows improvement in occupational performance and satisfaction. The Icelandic Quality of Life measurement also shows improvement. The results have been promising. However, a larger group is needed in order to draw clear unequivocal conclusions.  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