全文获取类型
收费全文 | 1673篇 |
免费 | 47篇 |
专业分类
管理学 | 281篇 |
民族学 | 9篇 |
人口学 | 112篇 |
丛书文集 | 6篇 |
理论方法论 | 198篇 |
综合类 | 16篇 |
社会学 | 826篇 |
统计学 | 272篇 |
出版年
2023年 | 11篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 31篇 |
2019年 | 52篇 |
2018年 | 44篇 |
2017年 | 59篇 |
2016年 | 43篇 |
2015年 | 45篇 |
2014年 | 58篇 |
2013年 | 273篇 |
2012年 | 67篇 |
2011年 | 58篇 |
2010年 | 54篇 |
2009年 | 45篇 |
2008年 | 59篇 |
2007年 | 54篇 |
2006年 | 52篇 |
2005年 | 52篇 |
2004年 | 48篇 |
2003年 | 44篇 |
2002年 | 43篇 |
2001年 | 41篇 |
2000年 | 33篇 |
1999年 | 37篇 |
1998年 | 30篇 |
1997年 | 31篇 |
1996年 | 15篇 |
1995年 | 22篇 |
1994年 | 24篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 17篇 |
1990年 | 15篇 |
1989年 | 7篇 |
1988年 | 24篇 |
1987年 | 15篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 18篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 21篇 |
1980年 | 16篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 7篇 |
排序方式: 共有1720条查询结果,搜索用时 15 毫秒
991.
Stephen Gorard 《International Journal of Social Research Methodology》2019,22(3):281-291
This paper compares the use of confidence intervals (CIs) and a sensitivity analysis called the number needed to disturb (NNTD), in the analysis of research findings expressed as ‘effect’ sizes. Using 1,000 simulations of randomised trials with up to 1,000 cases in each, the paper shows that both approaches are very similar in outcomes, and each one is highly predictable from the other. CIs are supposed to be a measure of likelihood or uncertainty in the results, showing a range of possible effect sizes that could have been produced by random sampling variation alone. NNTD is supposed to be a measure of the robustness of the effect size to any variation, including that produced by missing data. Given that they are largely equivalent and interchangeable under the conditions tested here, the paper suggests that both are really measures of robustness. It concludes that NNTD is to be preferred because it requires many fewer assumptions, is more tolerant of missing data, is easier to explain, and directly addresses the key question of whether the underlying effect size is zero or not. 相似文献
992.
In a 2015 policy change, the U.S. State Department released guidelines governing the sale of armed unmanned aerial vehicles (UAVs) to other countries, and several export agreements were signed shortly later. While considerable scholarly effort has been devoted to the impact or consequences of UAV proliferation, few studies have analyzed the actual diffusion process. This article applies the insights from both diffusion theory and policy transfer to examine the various diffusion mechanisms while using the experiences from Italy and Germany to illustrate distinct cases policy convergence and divergence, respectively. While the competition mechanism is typically constrained to policy adopting jurisdictions, evidence on armed UAV diffusion suggests policy transfer decisions can also hinge on competition among exporting jurisdictions. Consequently, we seek to point attention to the interaction between diffusion mechanisms (such as competition) and various domestic conditions, demonstrating that diffusion is neither apolitical nor necessarily neutral in character. 相似文献
993.
Manoel Bittencourt Shinhye Chang Rangan Gupta Stephen M. Miller 《Journal of Policy Modeling》2019,41(6):1043-1056
This paper examines the role of financial development on U.S. state-level income inequality in the 50 states from 1976 to 2011, using fixed-effect estimation. We find robust results whereby financial development linearly increases income inequality for the 50 states. When we divide 50 states into two separate groups of above-average and below-average inequality states than the cross-state average inequality, the effect of financial development on income inequality appears non-linear. When financial development improves, the effect increases at an increasing rate for above-average income-inequality states, whereas an inverted U-shaped relationship exists for below-average income-inequality states. To our knowledge, this paper is the first to examine the role of financial development on U.S. state-level inequality. 相似文献
994.
Stephen E. Bechtold 《决策科学》1991,22(1):157-170
This paper demonstrates that the problem of optimizing the work output of an individual employee, subject to a set of fixed-duration rest periods over a continuous time horizon, can be modeled with a quadratic programming formulation. Exogenous determination of break period durations may result from union contracts, management policies, or necessary lower bounds on break time due to transportation or other requirements. Although the new formulation is more complex than that required for previous models, an efficient solution procedure is presented which avoids the complexities of nonlinear programming. The number of iterations required for convergence is bounded from above by the number of rest periods to be scheduled and all computations are simple. An illustration of the procedure demonstrates that it may be effectively used without computer support. While this research was motivated by the fact that previous work-rest models were not applicable to work horizons which contained a fixed-duration meal break, the procedure can be used to obtain optimal placement for a set of fixed-duration rest periods which may or may not include a meal break. The characteristics of optimal strategies for a set of fixed-duration breaks proofs are shown to have implications for the design of shifts which are potentially more attractive and productive than shifts based upon typical practice. These characteristics are also compared to the general characteristics of optimal policies associated with endogenously determined break durations. This comparison provides insight into the possible consequences of exogenous determination of break durations. This paper concludes with suggestions for additional research. 相似文献
995.
Although interest in the ecological impacts of urbanisation has increased, very little is known about its impacts on freshwater
turtles in Australia. This study investigated the abundance and diversity of turtles in lakes in an urbanised subtropical
landscape, Brisbane, Australia. It was found that turtles were abundant throughout the lakes surveyed, with four native species
and one introduced species being detected. A total of 371 individuals were captured, 77.7% of which were Brisbane River turtle
(Emydura macquarii signata). The lakes surveyed were estimated to support a population of 63–269 individuals for all species combined with most lake
populations containing less than 100. Turtle demographics may be classed into three stages of population growth: recovery
or nascent; intermediate; and climax. Turtle reproductive success is a major concern for the survival of turtles in urban
areas. Continued monitoring is needed to establish if population declines are occurring. This study suggests that while turtles
are persisting in this urban environment of Australia the pressures of urbanisation, such as habitat loss, increased predation
on both nests and juveniles and pollution of waterways may pose on-going risks to their survival. 相似文献
996.
Yolanda Barbáchano D. Stephen Coad Derek R. Robinson 《Journal of statistical planning and inference》2008
Minimisation is a method often used in clinical trials to balance the treatment groups with respect to some prognostic factors. In the case of two treatments, the predictability of this method is calculated for different numbers of factors, different numbers of levels of each factor and for different proportions of the population at each level. It is shown that if we know nothing about the previous patients except the last treatment allocation, the next treatment can be correctly guessed more than 60% of the time if no biased coin is used. If the two previous assignments are known to have been the same, the next treatment can be guessed correctly around 80% of the time. Therefore, it is suggested that a biased coin should always be used with minimisation. Different choices of biased coin are investigated in terms of the reduction in predictability and the increase in imbalance that they produce. An alternative design to minimisation which makes use of optimum design theory is also investigated, by means of simulation, and does not appear to have any clear advantages over minimisation with a biased coin. 相似文献
997.
This paper proposes that the teacher, on the basis of action-research methodology, can produce two types of scientific knowledge: one based on the teacher as researcher (the teacher as ethnographer), and another based on the development of pedagogic action (the teacher as educator). The education of such a teacher, simultaneously a researcher and an educator, is carried out through the concretisation of that which has denominated the interface of intercultural education. The development of this interface renders possible the management of diversity by the teacher. This diversity is present both in the school, as well as, more specifically, in the classroom. It can also be seen as a source of wealth for the further deepening of the democratic nature of both the school and the education system. 相似文献
998.
The authors examine the usefulness of postmodernism in career counseling. Specifically, a case is made for broadening career counseling theories and techniques to feature the contextual influences inherent in each individual's unique career history. A career intervention, titled the Career‐O‐Gram, is introduced as a tool for exploring contextual influences on career development. A case study is presented to demonstrate the application of the Career‐O‐Gram. 相似文献
999.
P Brown S Zavestoski S McCormick M Linder J Mandelbaum T Luebke 《Journal of health and social behavior》2001,42(3):235-257
The social discovery of Gulf War-related illnesses, like other occupational and environmental disease, is firmly rooted in ongoing disputes over causation. Pressure from veterans groups, as well as intra-governmental disputes, have driven innovative research directions and challenged the dominant epidemiological paradigm. This dominant epidemiological paradigm was originally a position that viewed stress as the primary causal factor. In the emerging dominant epidemiological paradigm, researchers view veterans' symptoms as similar to other multi-symptom diseases and conditions, but with a firmer respect for the reality of those symptoms. In addition, some researchers pursue interactions between stress and physical exposure. We examine the evolution of the DEP to demonstrate that in many disease disputes, an affected population challenges government and science decision-making, and even ways of knowing, in an attempt to negotiate a disease definition and etiology that results in better treatment and prevention. After considerable research effort, only limited evidence has been found for environmental causation, and even many researchers sympathetic to veterans are doubtful that much more will be found. We analyze the social discovery and ongoing contestation of these illnesses, and the consequent effects on health and public policy. For extension to other disease disputes, we provide an overall model of disease discovery and contestation, examining the key forces of government, science, and citizens. 相似文献
1000.
The complex variety of experiences that characterize the current wave of immigration have prompted revisions in the classic model of straight-line assimilation; the most important alternative theory is based on the concept of "segmented" assimilation. This paper assesses the validity of these two perspectives with data on three generations of Hispanic immigrants in Houston. Contrary to the standard assimilation model, third-generation Hispanics are not staying in school longer, nor are they earning higher wages than members of the second generation. But contrary to the segmented-assimilation model, third-generation Hispanics also give no evidence at all of having assimilated into an "adversarial" culture that rejects mainstream American values and is presumably responsible for restricting their upward mobility. The data reaffirm the pivotal role of education in determining occupational mobility, and they point to the importance of identifying the external societal factors that account for the stalled progress in educational achievement among third-generation Hispanic Americans. 相似文献