全文获取类型
收费全文 | 27283篇 |
免费 | 530篇 |
国内免费 | 13篇 |
专业分类
管理学 | 3497篇 |
民族学 | 189篇 |
人才学 | 3篇 |
人口学 | 3876篇 |
丛书文集 | 177篇 |
教育普及 | 1篇 |
理论方法论 | 2203篇 |
综合类 | 1018篇 |
社会学 | 13463篇 |
统计学 | 3399篇 |
出版年
2023年 | 83篇 |
2021年 | 137篇 |
2020年 | 268篇 |
2019年 | 338篇 |
2018年 | 2007篇 |
2017年 | 2202篇 |
2016年 | 1451篇 |
2015年 | 376篇 |
2014年 | 428篇 |
2013年 | 2818篇 |
2012年 | 912篇 |
2011年 | 1712篇 |
2010年 | 1490篇 |
2009年 | 1213篇 |
2008年 | 1336篇 |
2007年 | 1507篇 |
2006年 | 577篇 |
2005年 | 713篇 |
2004年 | 662篇 |
2003年 | 583篇 |
2002年 | 476篇 |
2001年 | 432篇 |
2000年 | 387篇 |
1999年 | 356篇 |
1998年 | 265篇 |
1997年 | 235篇 |
1996年 | 277篇 |
1995年 | 237篇 |
1994年 | 212篇 |
1993年 | 204篇 |
1992年 | 241篇 |
1991年 | 225篇 |
1990年 | 219篇 |
1989年 | 212篇 |
1988年 | 217篇 |
1987年 | 217篇 |
1986年 | 200篇 |
1985年 | 212篇 |
1984年 | 223篇 |
1983年 | 184篇 |
1982年 | 176篇 |
1981年 | 153篇 |
1980年 | 143篇 |
1979年 | 161篇 |
1978年 | 128篇 |
1977年 | 103篇 |
1976年 | 119篇 |
1975年 | 130篇 |
1974年 | 93篇 |
1971年 | 72篇 |
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
31.
Sven Mallach 《Journal of Combinatorial Optimization》2018,36(3):871-895
We revise existing and introduce new mixed-integer programming models for the Multiprocessor scheduling problem with communication delays. The basis for both is the identification of two major modeling strategies one of which can be considered ordering-based, and the other assignment-based. We first reveal redundancies in the encoding of feasible solutions found in present formulations and discuss how they can be avoided. For the assignment-based approach, we propose new inequalities that lead to provably stronger continuous relaxations and better performance in practice. Moreover, we derive a third, novel modeling strategy and show how to more compactly linearize assignment formulations with quadratic constraints. In a comprehensive experimental comparison of representative models that reflect the state-of-the-art in terms of strength and size, we evaluate not only running times but also the obtained lower and upper bounds on the makespan for the harder instances of a large scale benchmark set. 相似文献
32.
Robert C. Cope Joshua V. Ross Talia A. Wittmann Michael J. Watts Phillip Cassey 《Risk analysis》2019,39(1):35-53
Understanding the risk of biological invasions associated with particular transport pathways and source regions is critical for implementing effective biosecurity management. This may require both a model for physical connectedness between regions, and a measure of environmental similarity, so as to quantify the potential for a species to be transported from a given region and to survive at a destination region. We present an analysis of integrated biosecurity risk into Australia, based on flights and shipping data from each global geopolitical region, and an adaptation of the “range bagging” method to determine environmental matching between regions. Here, we describe global patterns of environmental matching and highlight those regions with many physical connections. We classify patterns of global invasion risk (high to low) into Australian states and territories. We validate our analysis by comparison with global presence data for 844 phytophagous insect pest species, and produce a list of high‐risk species not previously known to be present in Australia. We determined that, of the insect pest species used for validation, the species most likely to be present in Australia were those also present in geopolitical regions with high transport connectivity to Australia, and those regions that were geographically close, and had similar environments. 相似文献
33.
The article investigates whether Austrian sociological research empirically addressed social class conceptions between 1945 and 1990. Contrary to the German reception, we find that, indeed, during the whole period scientific publications analyzed social relations and social change from a class perspective with an empirical approach. We embed this research in its historical context in order to work out the implicit explanations given concerning the existence of social inequalities. Moreover, we work out if post-World War II Austrian class analysis did link its work to the Austro-Marxist tradition that flourished between the two World Wars. The empirical focus of the article lies on scientific publications with an empirical approach to social classes and social change. 相似文献
34.
Vladimir Vanyushyn Maria Bengtsson Malin H. Näsholm Håkan Boter 《Review of Managerial Science》2018,12(2):535-557
International coopetition has rarely been studied in relation to innovation. Further exploration of effects of international coopetition, i.e. the pursuit of simultaneous cooperation and competition, on a firm’s innovation performance is especially important as such a relationship is challenging with a high propensity to fail. This observation formed the point of departure for this study, which aims to increase the understanding of the effects of international coopetition on firm innovativeness and how these effects are conditioned on the magnitude of the organizational adjustments a firm introduces. We use an unbalanced panel of 9839 firms that participated in four waves of the Swedish Community Innovation Survey between 2008 and 2014 as our empirical base. We illustrate that firms that cooperate with competitors internationally are more likely to exhibit higher propensity to introduce radical innovations, yet this effect is conditioned upon the magnitude of organizational adjustments. Overall, our study contributes to the understanding of the implications of international coopetition and what a firm needs to benefit from it. 相似文献
35.
David R. Williams Betty S. Coffey Carlton C. Young 《Journal of Management and Governance》2018,22(2):315-337
This paper examines the determinants of base pay and total incentive compensation packages of CEOs of biopharmaceutical firms that have recently gone public, and whether human capital and agency factors affect the market’s response to the initial public offering. We find that in terms of net proceeds, the IPO market appears to reward the firms that have founder-CEOs and CEOs with higher incentive compensation. CEOs with prior venture capital experience are associated with receiving higher incentive compensation, while CEOs with a greater ownership interest in the firm receive lower incentive compensation but higher salaries. CEOs of firms with a greater percentage of insiders are associated with lower salaries. The results should add to our understanding related to human capital and agency theories, as well as help firms and investors better understand and structure CEO compensation. 相似文献
36.
Yana Kucheva 《Demography》2018,55(2):617-642
Despite abundant evidence about the effect of children’s socioeconomic circumstances on their transition to adulthood, we know much less about the effect of social policy programs aimed at poor families with children in facilitating how and when children become adults. This issue is particularly important for the U.S. federal subsidized housing program given its long history of placing subsidized units in some of the poorest and most racially segregated neighborhoods. Using counterfactual causal methods that adjust for the length of receipt of subsidized housing, I estimate the effect of subsidized housing on teenage parenthood, household formation, and educational attainment. I find that the subsidized housing program has either null or positive effects on the transition to adulthood and that these effects vary by both race and gender. These results underscore the importance of considering whether social programs have differential effects on the life chances of individuals based on both race and gender. 相似文献
37.
Psychosocial benefits of activism include increased empowerment, social connectedness, and resilience. Yet sexual minority women (SMW) and transgender individuals with multiple oppressed statuses and identities are especially prone to oppression-based experiences, even within minority activist communities. This study sought to develop an empirical model to explain the diverse meanings of social justice activism situated in SMW and transgender individuals’ social identities, values, and experiences of oppression and privilege. Using a grounded theory design, 20 SMW and transgender individuals participated in initial, follow-up, and feedback interviews. The most frequent demographic identities were queer or bisexual, White, middle-class women with advanced degrees. The results indicated that social justice activism was intensely relational, replete with multiple benefits, yet rife with experiences of oppression from within and outside of activist communities. The empirically derived model shows the complexity of SMW and transgender individuals’ experiences, meanings, and benefits of social justice activism. 相似文献
38.
吕铖钢 《北京理工大学学报(社会科学版)》2021,23(2):152-160
税法中不确定概念下的理论空间以及税务行政的实践需求共同营造了税务行政裁量的制度空间,而不规范的税务行政裁量则为不规范的税收执法提供了操作机会。通过对税法文本中不确定概念理论缘由的寻求,以及税收征管中实践动因的梳理,税务行政裁量权的规范化确有必要性。为达成税法运行各司其职中的彼此制衡,有必要强化比例性原则在税务行政裁量中的运用,以此限制税权介入纳税人私域的范围与限度,并提供明确化的宏观指引;利用行政裁量基准“行政自制”与“规则之治”的双重品质,借助标准化的文本修正,为规范化的税收执法预设行为轨迹、构建外在制约并压缩裁量空间;以纳税人的同意权为基础,设计符合税法特殊性的程序规则,形成立体化的纳税人救济路径。最终形成税务行政裁量权积极运作与规范运行的制度环境。 相似文献
39.
Witkower Zachary Tracy Jessica L. Pun Anthea Baron Andrew S. 《Journal of Nonverbal Behavior》2021,45(4):505-518
Journal of Nonverbal Behavior - Past research has demonstrated that children understand distinct emotion concepts and can accurately recognize facial expressions of distinct emotions by a young... 相似文献
40.
There is considerable speculation that female political empowerment could improve population health. Yet, evidence to date is limited, and explanations for why political empowerment would matter and the conditions under which this might be enhanced or muted are not well understood. In this article, we draw on theoretical work on the politics of representation to frame an investigation of whether increases in the percentage of females in a country’s parliament influence mortality rates. We further examine whether the relationship is conditioned by extent of democracy and economic and social development. Through multivariate longitudinal regression, we analyze four indicators of mortality in 155 countries spanning 1990 to 2014 with controls for initial country conditions, time-stable structural predispositions to higher mortality, and a number of time-varying potential confounders. Results indicate that a high level of female representation—30 % or greater in our models—has large negative associations with mortality, that these are particularly strong in lesser developed and weak democratic contexts, that high female political representation effectively offsets liabilities associated with low development, and that the relationships are robust to various operationalizations of social development. In the end, our research provides a particularly thorough accounting of the relationship between female political representation and population health, particularly by specifying the conditions under which female representation is most salient. In doing so, the research suggests important links between issues of female empowerment, political context, and developmental trajectories of countries more generally. 相似文献