全文获取类型
收费全文 | 23600篇 |
免费 | 695篇 |
国内免费 | 1篇 |
专业分类
管理学 | 3554篇 |
民族学 | 109篇 |
人才学 | 2篇 |
人口学 | 2215篇 |
丛书文集 | 96篇 |
教育普及 | 2篇 |
理论方法论 | 2268篇 |
现状及发展 | 1篇 |
综合类 | 318篇 |
社会学 | 11609篇 |
统计学 | 4122篇 |
出版年
2023年 | 126篇 |
2021年 | 140篇 |
2020年 | 361篇 |
2019年 | 528篇 |
2018年 | 568篇 |
2017年 | 796篇 |
2016年 | 606篇 |
2015年 | 472篇 |
2014年 | 584篇 |
2013年 | 3743篇 |
2012年 | 809篇 |
2011年 | 806篇 |
2010年 | 592篇 |
2009年 | 502篇 |
2008年 | 591篇 |
2007年 | 629篇 |
2006年 | 606篇 |
2005年 | 585篇 |
2004年 | 554篇 |
2003年 | 482篇 |
2002年 | 543篇 |
2001年 | 632篇 |
2000年 | 614篇 |
1999年 | 547篇 |
1998年 | 398篇 |
1997年 | 375篇 |
1996年 | 363篇 |
1995年 | 342篇 |
1994年 | 324篇 |
1993年 | 343篇 |
1992年 | 392篇 |
1991年 | 361篇 |
1990年 | 328篇 |
1989年 | 337篇 |
1988年 | 333篇 |
1987年 | 284篇 |
1986年 | 279篇 |
1985年 | 304篇 |
1984年 | 309篇 |
1983年 | 289篇 |
1982年 | 251篇 |
1981年 | 213篇 |
1980年 | 198篇 |
1979年 | 223篇 |
1978年 | 199篇 |
1977年 | 177篇 |
1976年 | 149篇 |
1975年 | 170篇 |
1974年 | 130篇 |
1973年 | 124篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
C. A. Glasbey D. J. Allcroft 《Journal of the Royal Statistical Society. Series C, Applied statistics》2008,57(3):343-355
Summary. To investigate the variability in energy output from a network of photovoltaic cells, solar radiation was recorded at 10 sites every 10 min in the Pentland Hills to the south of Edinburgh. We identify spatiotemporal auto-regressive moving average models as the most appropriate to address this problem. Although previously considered computationally prohibitive to work with, we show that by approximating using toroidal space and fitting by matching auto-correlations, calculations can be substantially reduced. We find that a first-order spatiotemporal auto-regressive (STAR(1)) process with a first-order neighbourhood structure and a Matern noise process provide an adequate fit to the data, and we demonstrate its use in simulating realizations of energy output. 相似文献
202.
The ability to infer parameters of gene regulatory networks is emerging as a key problem in systems biology. The biochemical
data are intrinsically stochastic and tend to be observed by means of discrete-time sampling systems, which are often limited
in their completeness. In this paper we explore how to make Bayesian inference for the kinetic rate constants of regulatory
networks, using the stochastic kinetic Lotka-Volterra system as a model. This simple model describes behaviour typical of
many biochemical networks which exhibit auto-regulatory behaviour. Various MCMC algorithms are described and their performance
evaluated in several data-poor scenarios. An algorithm based on an approximating process is shown to be particularly efficient. 相似文献
203.
In this paper, we deal with a discrete-time multiserver retrial queue with finite population. Firstly, we study the Markov chain at the epochs immediately after slot boundaries making emphasis on the computation of its steady-state distribution. Then, the main performance measures are investigated. Besides, we simulate the waiting time of a customer in the retrial group under three different queueing policies. Some numerical examples are given to illustrate the analysis. 相似文献
204.
We propose four different GMM estimators that allow almost consistent estimation of the structural parameters of panel probit models with fixed effects for the case of small Tand large N. The moments used are derived for each period from a first order approximation of the mean of the dependent variable conditional on explanatory variables and on the fixed effect. The estimators differ w.r.t. the choice of instruments and whether they use trimming to reduce the bias or not. In a Monte Carlo study, we compare these estimators with pooled probit and conditional logit estimators for different data generating processes. The results show that the proposed estimators outperform these competitors in several situations. 相似文献
205.
Paul J. E. Miller John P. Caughlin Ted L. Huston 《Journal of marriage and the family》2003,65(4):978-995
This study examined the processes that underlie the association between trait expressiveness and marital satisfaction. A total of 168 newlywed couples participated in a four‐wave, 13‐year longitudinal study of marriage. Cross‐sectional and longitudinal path analyses suggested that expressiveness promotes satisfaction by leading spouses to engage in affectionate behavior and by leading them to idealize their partner. Expressive people formed idealized images of their partner because they brought out the best in their partner's behavior and because they interpreted their partner's behavior in a favorable light. The study extends previous research by showing that the benefits of trait expressiveness extend into the second decade of marriage and by providing a plausible explanation of the connections between trait expressiveness and marital satisfaction. 相似文献
206.
Michael Decker 《Poiesis & praxis》2004,2(2-3):139-156
Technology Assessment (TA) is a problem oriented endeavour dealing with political, societal, ecological, etc. problems. Only in rare cases is one individual scientific discipline sufficient to assess these problems. Usually the perspectives of different scientific disciplines have to be combined in order to develop interdisciplinary based recommendations to act. In this paper a quality controlled interdisciplinary discussion process is described which encourages an expert group to generate argumentation chains cross-cutting the disciplinary boundaries. The role of ethical reflection in this procedure depends on the problem situation. Whenever a technical application is on the agenda which cannot be allocated to a so-called “business-as-usual” case, one would ask for ethical reflection. This contribution argues that this ethical reflection has to take place together with the interdisciplinary discussion due to two reasons. Firstly, the technical, economical, legal and social aspects are deeply cross-correlated with the ethical reflection. And secondly, participating in such interdisciplinary discussions enables an ethical reflection which keeps in touch with the real world. Two case studies dealing with robotics applications in health care are mentioned as examples for problem settings, in which interdisciplinary TA succeed in developing discipline-crossing argumentation chains. 相似文献
207.
Nonlinguistic communication is typically proposed to convey representational messages, implying that particular signals are associated with specific signaler emotions, intentions, or external referents. However, common signals produced by both nonhuman primates and humans may not exhibit such specificity, with human laughter for example showing significant diversity in both acoustic form and production context. We therefore outline an alternative to the representational approach, arguing that laughter and other nonlinguistic vocalizations are used to influence the affective states of listeners, thereby also affecting their behavior. In the case of laughter, we propose a primary function of accentuating or inducing positive affect in the perceiver in order to promote a more favorable stance toward the laugher. Two simple strategies are identified, namely producing laughter with acoustic features that have an immediate impact on listener arousal, and pairing these sounds with positive affect in the listener to create learned affective responses. Both depend on factors like the listener's current emotional state and past interactions with the vocalizer, with laughers predicted to adjust their sounds accordingly. This approach is used to explain findings from two experimental studies that examined the use of laughter in same-sex and different-sex dyads composed of either friends or strangers, and may be applicable to other forms of nonlinguistic communication. 相似文献
208.
Joanna Burger Michael Gochfeld Karen Pletnikoff Ronald Snigaroff Daniel Snigaroff Tim Stamm 《Risk analysis》2008,28(5):1261-1272
It is becoming increasingly clear that scientists, managers, lawyers, public policymakers, and the public must decide how to value what is provided by, and is a consequence of, natural resources. While “Western” scientists have clear definitions for the goods and services that ecosystems provide, we contend that these categories do not encompass the full totality of the values provided by natural resources. Partly the confusion results from a limited view of natural resources derived from the need to monetize the value of ecosystems and their component parts. Partly it derives from the “Western” way of separating natural resources from cultural resources or values, and partly it derives from the false dichotomy of assuming that ecosystems are natural, and anything constructed by man is not natural. In this article, we explore the previous assumptions, and suggest that because cultural resources often derive from, and indeed require, intact and unspoiled natural ecosystems or settings, that these values are rightly part of natural resources. The distinction is not trivial because of the current emphasis on cleaning up chemically and radiologically contaminated sites, on restoration of damaged ecosystems, on natural resource damage assessments, and on long‐term stewardship goals. All of these processes depend upon defining natural resources appropriately. Several laws, regulations, and protocols depend upon natural resource trustees to protect natural resources on trust lands, which could lead to the circular definition that natural resources are those resources that the trustees feel they are responsible for. Where subsistence or tribal peoples are involved, the definition of natural resources should be broadened to include those ecocultural attributes that are dependent upon, and have incorporated, natural resources. For example, a traditional hunting and fishing ground is less valued by subsistence peoples if it is despoiled by contamination or physical ecosystem degradation; an Indian sacred ground is tarnished if the surrounding natural environment is degraded; a traditional homeland is less valued if the land itself is contaminated. Our argument is that intact natural resources are essential elements of many cultural resources, and this aspect requires and demands adequate consideration (and may therefore require compensation). 相似文献
209.
Urban elites are increasingly addressing local social problems though policies that turn their cities into tourist destinations. Often at the heart of these policies are new publicly financed sports stadiums. Ironically, this strategy is flourishing despite near-unanimous academic criticism, and increasing public skepticism, about this approach. Our research addresses this contradiction by exploring how and why powerful decisionmakers continue supporting publicly financed stadiums. We rely on local growth coalition theory to explore this topic because it offers analytical advantages, including looking beyond local sports teams as the focal point of these initiatives, addressing the variation in the outcomes of these initiatives, and acknowledging that policymakers are predisposed toward supporting these initiatives but that this predisposition does not always result in success. 相似文献
210.
Drug treatment courts (DTCs), an alternative to traditional criminal courts, provide an innovative way to legally process some drug offenders. The origin and recent growth of the drug court system in the USA can be explained as an unintended consequence of a failing 'war on drugs'. In this article, we discuss the spread of adult DTCs throughout the USA, the main components of drug courts, controversies surrounding DTCs, and some criticisms of drug courts. We summarize the recent evaluations of adult DTCs, and highlight various DTC factors that have been found to reduce individual drug use and criminal activity. We also offer suggestions for future research on DTCs and conclude with policy recommendations. 相似文献