全文获取类型
收费全文 | 4958篇 |
免费 | 201篇 |
国内免费 | 92篇 |
专业分类
管理学 | 1238篇 |
民族学 | 4篇 |
人口学 | 23篇 |
丛书文集 | 221篇 |
理论方法论 | 195篇 |
综合类 | 2083篇 |
社会学 | 240篇 |
统计学 | 1247篇 |
出版年
2024年 | 9篇 |
2023年 | 38篇 |
2022年 | 66篇 |
2021年 | 67篇 |
2020年 | 96篇 |
2019年 | 133篇 |
2018年 | 126篇 |
2017年 | 200篇 |
2016年 | 155篇 |
2015年 | 147篇 |
2014年 | 198篇 |
2013年 | 520篇 |
2012年 | 273篇 |
2011年 | 247篇 |
2010年 | 207篇 |
2009年 | 222篇 |
2008年 | 273篇 |
2007年 | 277篇 |
2006年 | 310篇 |
2005年 | 302篇 |
2004年 | 252篇 |
2003年 | 217篇 |
2002年 | 185篇 |
2001年 | 149篇 |
2000年 | 129篇 |
1999年 | 87篇 |
1998年 | 59篇 |
1997年 | 45篇 |
1996年 | 49篇 |
1995年 | 34篇 |
1994年 | 31篇 |
1993年 | 25篇 |
1992年 | 26篇 |
1991年 | 18篇 |
1990年 | 14篇 |
1989年 | 17篇 |
1988年 | 21篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1981年 | 6篇 |
排序方式: 共有5251条查询结果,搜索用时 15 毫秒
31.
A growing literature examines the empirical relationship between the joint reproductive preferences of marital partners and reproductive outcomes in Africa. Less explored is how spousal power in decision making may be influenced by lineage type. Using pooled data from Ghana, we investigate how lineage affects gendered reproductive decision outcomes and find some evidence that matrilineal women are more able than nonmatrilineal women to translate their reproductive preferences into action consistent with their goals. 相似文献
32.
Point processes are the stochastic models most suitable for describing physical phenomena that appear at irregularly spaced
times, such as the earthquakes. These processes are uniquely characterized by their conditional intensity, that is, by the
probability that an event will occur in the infinitesimal interval (t, t+Δt), given the history of the process up tot. The seismic phenomenon displays different behaviours on different time and size scales; in particular, the occurrence of
destructive shocks over some centuries in a seismogenic region may be explained by the elastic rebound theory. This theory
has inspired the so-called stress release models: their conditional intensity translates the idea that an earthquake produces
a sudden decrease in the amount of strain accumulated gradually over time along a fault, and the subsequent event occurs when
the stress exceeds the strength of the medium. This study has a double objective: the formulation of these models in the Bayesian
framework, and the assignment to each event of a mark, that is its magnitude, modelled through a distribution that depends
at timet on the stress level accumulated up to that instant. The resulting parameter space is constrained and dependent on the data,
complicating Bayesian computation and analysis. We have resorted to Monte Carlo methods to solve these problems. 相似文献
33.
论企业意会知识的管理 总被引:2,自引:0,他引:2
通过对持续竞争优势的深入研究 ,认识到意会知识对企业越来越重要。文章简要地阐明了意会知识对企业持续竞争优势的重要意义 ,分析了企业意会知识的分类框架和表现形式 ,并探讨企业如何加强知识管理使意会知识成为持续竞争优势的基础。 相似文献
34.
提出了非负权最短路问题的一种新算法。与有名的Dijkstra算法相比,这种算法计算简便、容易理解、易于编程。 相似文献
35.
建立了有柔性路径的FMS动态调度问题的模型.采用离线重调度的方法,提出一种结合离线重调度两种生成调度方式的方法来阐述FMS的有柔性路径动态调度问题.最后给出了该问题的遗传算法解决方法和计算示例. 相似文献
36.
我国地方政府竞争的趋势将愈演愈烈,地方政府竞争带来了不同的竞争效应。文章对地方政府竞争模型的反思入手,分析了民族地区政府竞争的特征和存在问题的基础上,提出了民族地区提升政府竞争力的路径选择:以提升制度竞争力为先,推进市场、产品等要素建设;并对民族地区政府竞争提出相应的制度和政策安排。 相似文献
37.
提出了一种基于定位辅助按需拓扑维护的超宽带自组网路由算法,该算法利用超宽带技术精确定位信息所获得的网络拓扑信息和路由信息进行分组转发,路由维护阶段在定位信息辅助下采用按需方式进行断链路由的修复和拓扑维护,通过基于位置信息的按需路由发现和限制路由查找范围,以及定位信息和网络拓扑信息的及时更新,在降低协议开销的同时保证了算法的有效性。仿真表明,该算法在分组丢失率、平均端到端时延和路由附加开销等方面具有良好性能,其优良的分布式控制特征能适应超宽带自组网的动态环境。 相似文献
38.
Fifteen Years of Family Group Conferencing: Coordinators Talk About Their Experiences in Aotearoa New Zealand 总被引:1,自引:0,他引:1
Family Group Conferencing (FGC) as a solution-focused strategyin child welfare has now been a mandated practice in AotearoaNew Zealand since 1989. This qualitative study examines theexperiences of Care and Protection Coordinators who have beenconvening FGC since the early years of the legislation. Thestudy explores early perceptions of the legislation, what firstattracted them to the role and what keeps them in the job. Inparticular, the study explores the practice tensions that restwithin family-centred child protection models, and the waysin which FGC practice has developed in response to modern imperatives. 相似文献
39.
The HastingsMetropolis algorithm is a general MCMC method for sampling from a density known up to a constant. Geometric convergence of this algorithm has been proved under conditions relative to the instrumental (or proposal) distribution. We present an inhomogeneous HastingsMetropolis algorithm for which the proposal density approximates the target density, as the number of iterations increases. The proposal density at the n th step is a non-parametric estimate of the density of the algorithm, and uses an increasing number of i.i.d. copies of the Markov chain. The resulting algorithm converges (in n ) geometrically faster than a HastingsMetropolis algorithm with any fixed proposal distribution. The case of a strictly positive density with compact support is presented first, then an extension to more general densities is given. We conclude by proposing a practical way of implementation for the algorithm, and illustrate it over simulated examples. 相似文献
40.
Marco Bee 《Statistical Methods and Applications》2005,14(1):127-141
In this article we provide a rigorous treatment of one of the central statistical issues of credit risk management. GivenK-1 rating categories, the rating of a corporate bond over a certain horizon may either stay the same or change to one of the
remainingK-2 categories; in addition, it is usually the case that the rating of some bonds is withdrawn during the time interval considered
in the analysis. When estimating transition probabilities, we have thus to consider aK-th category, called withdrawal, which contains (partially) missing data. We show how maximum likelihood estimation can be
performed in this setup; whereas in discrete time our solution gives rigorous support to a solution often used in applications,
in continuous time the maximum likelihood estimator of the transition matrix computed by means of the EM algorithm represents
a significant improvement over existing methods. 相似文献