首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3802篇
  免费   80篇
管理学   552篇
民族学   36篇
人口学   376篇
丛书文集   21篇
理论方法论   394篇
综合类   43篇
社会学   1815篇
统计学   645篇
  2023年   36篇
  2022年   22篇
  2021年   21篇
  2020年   82篇
  2019年   100篇
  2018年   128篇
  2017年   176篇
  2016年   150篇
  2015年   110篇
  2014年   131篇
  2013年   745篇
  2012年   128篇
  2011年   132篇
  2010年   104篇
  2009年   105篇
  2008年   115篇
  2007年   96篇
  2006年   84篇
  2005年   91篇
  2004年   101篇
  2003年   63篇
  2002年   85篇
  2001年   78篇
  2000年   59篇
  1999年   64篇
  1998年   46篇
  1997年   44篇
  1996年   42篇
  1995年   33篇
  1994年   44篇
  1993年   34篇
  1992年   44篇
  1991年   46篇
  1990年   35篇
  1989年   27篇
  1988年   43篇
  1987年   36篇
  1986年   34篇
  1985年   28篇
  1984年   21篇
  1983年   25篇
  1982年   23篇
  1981年   19篇
  1980年   24篇
  1979年   23篇
  1978年   30篇
  1977年   22篇
  1976年   16篇
  1975年   22篇
  1974年   15篇
排序方式: 共有3882条查询结果,搜索用时 12 毫秒
101.
现代逻辑的价值和意义,在于其在理论上的应用。对于纯数学的基础和结构来说,现代逻辑是一种非常有用的工具,包括哥德尔不完全性定理等,都利用了现代逻辑的技术和成果。某些现代逻辑技术已经广泛应用到了工程学之中,例如,计算机工程就基于现代逻辑的高级成果。反过来,这些应用又刺激了逻辑理论本身取得更多的进步。  相似文献   
102.
介绍了怀特海关于文明的理论,这一理论关注表象与实在的区别以及文明的五种特质——艺术、真、美、探险、安宁。认为这些观念可以作为桥梁性原理连接对怀特海一般理论的整合与扩充。认为怀特海思想能够给心理治疗的性质和过程提供重要洞见。  相似文献   
103.
The three classic pillars of risk analysis are risk assessment (how big is the risk and how sure can we be?), risk management (what shall we do about it?), and risk communication (what shall we say about it, to whom, when, and how?). We propose two complements as important parts of these three bases: risk attribution (who or what addressable conditions actually caused an accident or loss?) and learning from experience about risk reduction (what works, and how well?). Failures in complex systems usually evoke blame, often with insufficient attention to root causes of failure, including some aspects of the situation, design decisions, or social norms and culture. Focusing on blame, however, can inhibit effective learning, instead eliciting excuses to deflect attention and perceived culpability. Productive understanding of what went wrong, and how to do better, thus requires moving past recrimination and excuses. This article identifies common blame‐shifting “lame excuses” for poor risk management. These generally contribute little to effective improvements and may leave real risks and preventable causes unaddressed. We propose principles from risk and decision sciences and organizational design to improve results. These start with organizational leadership. More specifically, they include: deliberate testing and learning—especially from near‐misses and accident precursors; careful causal analysis of accidents; risk quantification; candid expression of uncertainties about costs and benefits of risk‐reduction options; optimization of tradeoffs between gathering additional information and immediate action; promotion of safety culture; and mindful allocation of people, responsibilities, and resources to reduce risks. We propose that these principles provide sound foundations for improving successful risk management.  相似文献   
104.
The use of thimerosal preservative in childhood vaccines has been largely eliminated over the past decade in the United States because vaccines have been reformulated in single‐dose vials that do not require preservative. An exception is the inactivated influenza vaccines, which are formulated in both multidose vials requiring preservative and preservative‐free single‐dose vials. As part of an ongoing evaluation by USFDA of the safety of biologics throughout their lifecycle, the infant body burden of mercury following scheduled exposures to thimerosal preservative in inactivated influenza vaccines in the United States was estimated and compared to the infant body burden of mercury following daily exposures to dietary methylmercury at the reference dose established by the USEPA. Body burdens were estimated using kinetic parameters derived from experiments conducted in infant monkeys that were exposed episodically to thimerosal or MeHg at identical doses. We found that the body burden of mercury (AUC) in infants (including low birth weight) over the first 4.5 years of life following yearly exposures to thimerosal was two orders of magnitude lower than that estimated for exposures to the lowest regulatory threshold for MeHg over the same time period. In addition, peak body burdens of mercury following episodic exposures to thimerosal in this worst‐case analysis did not exceed the corresponding safe body burden of mercury from methylmercury at any time, even for low‐birth‐weight infants. Our pharmacokinetic analysis supports the acknowledged safety of thimerosal when used as a preservative at current levels in certain multidose infant vaccines in the United States.  相似文献   
105.
We study the computational complexity of the vertex 3-colorability problem in the class of claw-free graphs. Both the problem and the class received much attention in the literature, separately of each other. However, very little is known about the 3-colorability problem restricted to the class of claw-free graphs beyond the fact the problem is NP-complete under this restriction. In this paper we first strengthen this negative fact by revealing various further restrictions under which the problem remains NP-complete. Then we derive a number of positive results that deal with polynomially solvable cases of the problem in the class of claw-free graphs.  相似文献   
106.
107.
A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.  相似文献   
108.
Fault diagnosis includes the main task of classification. Bayesian networks (BNs) present several advantages in the classification task, and previous works have suggested their use as classifiers. Because a classifier is often only one part of a larger decision process, this article proposes, for industrial process diagnosis, the use of a Bayesian method called dynamic Markov blanket classifier that has as its main goal the induction of accurate Bayesian classifiers having dependable probability estimates and revealing actual relationships among the most relevant variables. In addition, a new method, named variable ordering multiple offspring sampling capable of inducing a BN to be used as a classifier, is presented. The performance of these methods is assessed on the data of a benchmark problem known as the Tennessee Eastman process. The obtained results are compared with naive Bayes and tree augmented network classifiers, and confirm that both proposed algorithms can provide good classification accuracies as well as knowledge about relevant variables.  相似文献   
109.
ABSTRACT

This paper explores the challenges of outsidership faced by multinational companies (MNCs) accessing emerging economies. The paper departs from popular conceptualisations of culture drawing instead on social identity theory as part of an institutions-based view, to explain how employing a singularities approach can allow the identification of commonalities of Indianness and Australianness that can be leveraged to ameliorate negative socially embedded business norms that pose a challenge to MNC success in emerging economies. This study shows that despite recognised formal (regulatory) and informal (cultural) differences, managers of Australian MNCs operating in India were able to innovatively identify and exploit cultural commonalties/singularities to ease cultural adjustment and mitigate intergroup conflict, allowing them to achieve an innovative institutional fit. The paper discusses how, using this approach, sole-venture MNCs can access many of the benefits provided by collaborative entry modes while preserving MNC identity. We further propose that the singularities approach can provide a valuable starting point to develop culturally appropriate competence training initiatives.  相似文献   
110.
Much research suggests that political experts are more likelyto structure attitudes toward different issues in an ideologicallyconsistent fashion. Based on recent studies of motivationalinfluences on social cognition, we hypothesize that only expertswith a high need to evaluate—a strong motivation to establishevaluations of social objects—may "apply" ideology toa variety of issues. Data from the 1998 NES Pilot and 2000 NESare used to examine this hypothesis. While experts do show moreideological constraint, this relationship appears to be limitedto individuals with a high need to evaluate. Additional analysesindicated that this interactive effect extended to other indicesof the use of ideology as well.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号