全文获取类型
收费全文 | 23046篇 |
免费 | 803篇 |
国内免费 | 236篇 |
专业分类
管理学 | 1920篇 |
劳动科学 | 4篇 |
民族学 | 301篇 |
人才学 | 1篇 |
人口学 | 620篇 |
丛书文集 | 1576篇 |
理论方法论 | 1679篇 |
综合类 | 12920篇 |
社会学 | 2356篇 |
统计学 | 2708篇 |
出版年
2024年 | 44篇 |
2023年 | 218篇 |
2022年 | 244篇 |
2021年 | 312篇 |
2020年 | 510篇 |
2019年 | 590篇 |
2018年 | 613篇 |
2017年 | 762篇 |
2016年 | 678篇 |
2015年 | 706篇 |
2014年 | 1208篇 |
2013年 | 2304篇 |
2012年 | 1472篇 |
2011年 | 1525篇 |
2010年 | 1247篇 |
2009年 | 1223篇 |
2008年 | 1329篇 |
2007年 | 1478篇 |
2006年 | 1434篇 |
2005年 | 1176篇 |
2004年 | 1097篇 |
2003年 | 1002篇 |
2002年 | 834篇 |
2001年 | 619篇 |
2000年 | 426篇 |
1999年 | 211篇 |
1998年 | 109篇 |
1997年 | 114篇 |
1996年 | 106篇 |
1995年 | 90篇 |
1994年 | 69篇 |
1993年 | 61篇 |
1992年 | 47篇 |
1991年 | 27篇 |
1990年 | 31篇 |
1989年 | 34篇 |
1988年 | 26篇 |
1987年 | 25篇 |
1986年 | 22篇 |
1985年 | 15篇 |
1984年 | 16篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
Jens Jetzkowitz C.S.A. van Koppen Rolf Lidskog Konrad Ott Lieske Voget-Kleschin Catherine Mei Ling Wong 《Innovation: The European Journal of Social Science Research》2018,31(1):S38-S60
The term “biodiversity” is often used to describe phenomena of nature, which can be studied without a reference to the socially constructed, evaluative, or indeed normative contexts. In our paper, we challenge this conception by focusing particularly on methodological aspects of biodiversity research. We thereby engage with the idea of interdisciplinary biodiversity research as a scientific approach directed at the recognition and management of contemporary society in its ecological embedding. By doing this, we explore how research on and assessments of biodiversity can be enhanced if meaning, aspiration, desires, and related aspects of agency are methodically taken into account. In six sections, we substantiate our claim that the discourse on biodiversity (including the IPBES (Intergovernmental science-policy Platform on Biodiversity and Ecosystem Services) debate) is incomplete without contributions from the social sciences and humanities. In the introduction, a brief overview of biodiversity’s conceptual history is provided showing that “biodiversity” is a lexical invention intended to create a strong political momentum. However, that does not impede its usability as a research concept. Section 2 examines the origins of the Convention on Biological Diversity (CBD) by way of sociological discourse analysis. Subsequently, it proposes a matrix as a means to structure the ambiguities and tensions inherent in the CBD. The matrix reemphasizes our main thesis regarding the need to bring social and ethical expertise to the biodiversity discourse. In Section 3, we offer a brief sketch of the different methods of the natural and social sciences as well as ethics. This lays the groundwork for our Section 4, which explains and illustrates what social sciences and ethics can contribute to biodiversity research. Section 5 turns from research to politics and argues that biodiversity governance necessitates deliberative discourses in which participation of lay people plays an important role. Section 6 provides our conclusions. 相似文献
962.
ABSTRACTDespite both scholarly and popular claims that citizen journalism (CJ) represents a growing democratizing force in the journalistic field, recent scholarship in the area has noted the decline of the organizational population of CJ. In this paper, we investigate how individual characteristics of sites and the dynamics of larger organizational population affect a CJ site’s risk of experiencing a mortality. Drawing on the largest sample to date of US-based English-language CJ sites, this study examines the risk of site mortality through an event history framework. Findings indicate that the strongest predictor of a site’s mortality is the age of the site, consistent with organizational population theory’s ‘liability of newness.’ We also find that for-profit and community-based sites have lower rates of site mortality, indicating that adopting legitimate conventions of journalism may serve as a protective buffer to site death. The results offer mixed evidence on whether CJ has become more professionalized via attrition. 相似文献
963.
This article intends to contribute to the increasing body of academic literature on the frontline delivery of activation policies. In line with the broader literature on frontline work, this literature focuses attention on frontline delivery practices and preferences and how these can be explained. Activation work is an interesting case in this context, because activation workers’ jobs designs vary considerably and workers have a diversity of educational backgrounds (including but not limited to social work) in the many countries that have implemented activation policies. This article looks at workers’ preferences rather than actual delivery practices. It analyses how job design and educational background are related to workers’ preferences concerning servicing clients, managing activation workers and spending time on various activation-related activities. Although the findings of the research that are presented in the article show that educational background and job design play only a modest role as antecedents of workers’ preferences, future research into this issue remains interesting. For it may help to increase our insights into the optimal match between what activation aims to achieve and how the provision of activation is organized on the one hand, and workers’ skills/qualifications and job design on the other hand. 相似文献
964.
ABSTRACTThis article identifies trends in the adoption and implementation of quotas for corporate boards, an underresearched topic in political science. Corporate quotas—like legislative quotas—constitute the “fast track” to gender equality but appear more commonly in advanced democracies. These corporate quotas fall into three categories: laws covering all companies; laws covering state-owned companies only; and nonbinding (voluntary) measures in corporate governance codes. Despite on-paper differences, these corporate quotas are largely toothless. First generation corporate quotas, like first generation legislative quotas, operate symbolically. By raising the specter of stringent legislation in the long run, corporate quotas induce firms into voluntary compliance in the short run. 相似文献
965.
Judite Leite Hugo S. Gomes Andreia de Castro-Rodrigues Rui Abrunhosa Gonçalves 《Journal of Child Custody》2018,15(2):116-135
In Portugal, there is a gap regarding psychological tests validated for forensic contexts, particularly those related to child custody issues. The Parent–Child Relationship Inventory (PCRI) is one of the most used instruments in child custody contexts. This study aimed to analyze the psychometric properties of PCRI in a Portuguese forensic sample. PCRI factorial structure and psychometric properties were analyzed in a sample of 144 parents involved in child custody assessments. The questionnaire showed good internal consistency, except for the parental support, autonomy, and role orientation scales. It also showed good discriminant capacity. The confirmatory factor analysis did not replicate the 7-factor model proposed by Gerard. The results were discussed based on the use of PCRI in the context of child custody assessment. 相似文献
966.
We propose an adaptive functional autoregressive (AFAR) forecast model to predict electricity price curves. With time-varying operators, the AFAR model can be safely used in both stationary and nonstationary situations. A closed-form maximum likelihood (ML) estimator is derived under stationarity. The result is further extended for nonstationarity, where the time-dependent operators are adaptively estimated under local homogeneity. We provide theoretical results of the ML estimator and the adaptive estimator. Simulation study illustrates nice finite sample performance of the AFAR modeling. The AFAR model also exhibits a superior accuracy in the forecast exercise of the California electricity daily price curves compared to several alternatives. 相似文献
967.
Estimates of subgroup treatment effects in overall nonsignificant trials: To what extent should we believe in them? 下载免费PDF全文
Julien Tanniou Ingeborg van der Tweel Steven Teerenstra Kit C.B. Roes 《Pharmaceutical statistics》2017,16(4):280-295
In drug development, it sometimes occurs that a new drug does not demonstrate effectiveness for the full study population but appears to be beneficial in a relevant subgroup. In case the subgroup of interest was not part of a confirmatory testing strategy, the inflation of the overall type I error is substantial and therefore such a subgroup analysis finding can only be seen as exploratory at best. To support such exploratory findings, an appropriate replication of the subgroup finding should be undertaken in a new trial. We should, however, be reasonably confident in the observed treatment effect size to be able to use this estimate in a replication trial in the subpopulation of interest. We were therefore interested in evaluating the bias of the estimate of the subgroup treatment effect, after selection based on significance for the subgroup in an overall “failed” trial. Different scenarios, involving continuous as well as dichotomous outcomes, were investigated via simulation studies. It is shown that the bias associated with subgroup findings in overall nonsignificant clinical trials is on average large and varies substantially across plausible scenarios. This renders the subgroup treatment estimate from the original trial of limited value to design the replication trial. An empirical Bayesian shrinkage method is suggested to minimize this overestimation. The proposed estimator appears to offer either a good or a conservative correction to the observed subgroup treatment effect hence provides a more reliable subgroup treatment effect estimate for adequate planning of future studies. 相似文献
968.
The paper investigates various nonparametric models including regression, conditional distribution, conditional density and conditional hazard function, when the covariates are infinite dimensional. The main contribution is to prove uniform in bandwidth asymptotic results for kernel estimators of these functional operators. Then, the application issues, involving data-driven bandwidth selection, are discussed. 相似文献
969.
C. J. Brien 《Australian & New Zealand Journal of Statistics》2017,59(4):327-352
Multiphase experiments are introduced and an overview of their design and analysis as it is currently practised is given via an account of their development since 1955 and a literature survey. Methods that are available for designing and analysing them are outlined, with an emphasis on making explicit the role of the model in their design. The availability of software and its use is described in detail. Overall, while multiphase designs have been applied in areas such as plant breeding, plant pathology, greenhouse experimentation, product storage, gene expression studies, and sensory evaluation, their deployment has been limited. 相似文献
970.
We study a system of two non-identical and separate M/M/1/? queues with capacities (buffers) C1 < ∞ and C2 = ∞, respectively, served by a single server that alternates between the queues. The server’s switching policy is threshold-based, and, in contrast to other threshold models, is determined by the state of the queue that is not being served. That is, when neither queue is empty while the server attends Qi (i = 1, 2), the server switches to the other queue as soon as the latter reaches its threshold. When a served queue becomes empty we consider two switching scenarios: (i) Work-Conserving, and (ii) Non-Work-Conserving. We analyze the two scenarios using Matrix Geometric methods and obtain explicitly the rate matrix R, where its entries are given in terms of the roots of the determinants of two underlying matrices. Numerical examples are presented and extreme cases are investigated. 相似文献