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   116807篇
  免费   5034篇
  国内免费   880篇
管理学   1865篇
劳动科学   26篇
民族学   1880篇
人才学   9篇
人口学   1597篇
丛书文集   16562篇
理论方法论   5194篇
综合类   87214篇
社会学   3957篇
统计学   4417篇
  2024年   81篇
  2023年   514篇
  2022年   803篇
  2021年   938篇
  2020年   1177篇
  2019年   1061篇
  2018年   1123篇
  2017年   1454篇
  2016年   1584篇
  2015年   2188篇
  2014年   5430篇
  2013年   6641篇
  2012年   6898篇
  2011年   8335篇
  2010年   6834篇
  2009年   6983篇
  2008年   7401篇
  2007年   9361篇
  2006年   9464篇
  2005年   8814篇
  2004年   8436篇
  2003年   8127篇
  2002年   6580篇
  2001年   5529篇
  2000年   3235篇
  1999年   912篇
  1998年   459篇
  1997年   365篇
  1996年   314篇
  1995年   267篇
  1994年   200篇
  1993年   169篇
  1992年   128篇
  1991年   117篇
  1990年   64篇
  1989年   56篇
  1988年   62篇
  1987年   20篇
  1986年   25篇
  1985年   96篇
  1984年   99篇
  1983年   71篇
  1982年   64篇
  1981年   59篇
  1980年   50篇
  1979年   52篇
  1978年   46篇
  1977年   16篇
  1976年   11篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 412 毫秒
991.
1986年,兴隆洼文化遗址出土一支骨笛,经专家研究鉴定、修复、测音、演奏,证明了它是中国远古时期最早的乐器之一。证明中国音乐的历史和乐器制作史,距今已有8000多年,同时还证明了8000年前中国音乐的构成,不仅有5声音阶、6声音阶,还有7声音阶,把中国7声音阶的历史提前到了8000年前。对推动中华文明的探源工程有着极为深远的意义,对进一步研究中国乃至世界音乐史意义重大。  相似文献   
992.
While combing through the threads of the history of the Zhang Zhung kingdom,one of the first things that we cannot avoid is its position in historical time. As we know,from the perspec-tive of literary...  相似文献   
993.
Over the last decade the health and environmental research communities have made significant progress in collecting and improving access to genomic, toxicology, exposure, health, and disease data useful to health risk assessment. One of the barriers to applying these growing volumes of information in fields such as risk assessment is the lack of informatics tools to organize, curate, and evaluate thousands of journal publications and hundreds of databases to provide new insights on relationships among exposure, hazard, and disease burden. Many fields are developing ontologies as a way of organizing and analyzing large amounts of complex information from multiple scientific disciplines. Ontologies include a vocabulary of terms and concepts with defined logical relationships to each other. Building from the recently published exposure ontology and other relevant health and environmental ontologies, this article proposes an ontology for health risk assessment (RsO) that provides a structural framework for organizing risk assessment information and methods. The RsO is anchored by eight major concepts that were either identified by exploratory curations of the risk literature or the exposure‐ontology working group as key for describing the risk assessment domain. These concepts are: (1) stressor, (2) receptor, (3) outcome, (4) exposure event, (5) dose‐response approach, (6) dose‐response metric, (7) uncertainty, and (8) measure of risk. We illustrate the utility of these concepts for the RsO with example curations of published risk assessments for ionizing radiation, arsenic in drinking water, and persistent pollutants in salmon.  相似文献   
994.
In response to COVID‐19 hygiene and physical distancing restrictions, our service rapidly shifted to delivering Circle of Security‐Parenting? (COS‐P) groups via telehealth. In this article we report the perspectives and experiences of the group facilitator and the parents who received the intervention during the COVID‐19 pandemic. We use semi‐structured, qualitative interviews to explore the advantages, challenges, and positive impacts of the online parenting group from the perspectives of the group leader and the five group participants. Participants’ narrative reflections show that they were satisfied with the convenient and engaging online delivery of the program and would recommend it to other parents. Parents reported significant improvements in their parenting and greater awareness of their strengths and struggles. The online delivery of COS‐P resulted in more efficient service delivery, greater attendance rates, and adherence to the model. The stressors on the experienced facilitator, due to the abrupt transition and multiple technical and communication challenges, may have been mitigated by supervisor and collegial support, as well as careful preparation for herself and the participants. Future research should investigate the effectiveness of online versus face‐to‐face delivery of the intervention, including what works for whom.  相似文献   
995.
We propose here a general statistic for the goodness of fit test of statistical distributions. The proposed statistic is constructed based on an estimate of Kullback–Leibler information. The proposed test is consistent and the limiting distribution of the test statistic is derived. Then, the established results are used to introduce goodness of fit tests for the normal, exponential, Laplace and Weibull distributions. A simulation study is carried out for examining the power of the proposed test and to compare it with those of some existing procedures. Finally, some illustrative examples are presented and analysed, and concluding comments are made.  相似文献   
996.
Wanbo Lu  Dong Yang  Kris Boudt 《Statistics》2019,53(3):471-488
The traditional estimation of higher order co-moments of non-normal random variables by the sample analog of the expectation faces a curse of dimensionality, as the number of parameters increases steeply when the dimension increases. Imposing a factor structure on the process solves this problem; however, it leads to the challenging task of selecting an appropriate factor model. This paper contributes by proposing a test that exploits the following feature: when the factor model is correctly specified, the higher order co-moments of the unexplained return variation are sparse. It recommends a general to specific approach for selecting the factor model by choosing the most parsimonious specification for which the sparsity assumption is satisfied. This approach uses a Wald or Gumbel test statistic for testing the joint statistical significance of the co-moments that are zero when the factor model is correctly specified. The asymptotic distribution of the test is derived. An extensive simulation study confirms the good finite sample properties of the approach. This paper illustrates the practical usefulness of factor selection on daily returns of random subsets of S&P 100 constituents.  相似文献   
997.
The current study assesses the association between several work-related factors and psychological distress among social workers (SWs) in Israel. The data were collected through structured questionnaires, administered to a sample of 494 SWs. The findings suggest that most of the examined work-related factors (namely, years of professional experience, personal work-related subjection to violence, burnout, compassion fatigue, and sense of coherence), with the exception of compassion satisfaction, significantly predicted psychological distress among SWs. The conclusion is that it is important to embed within the social work practice strategies for reducing sources of psychological distress (job demands) and increasing material, professional, and personal resources. Reducing the levels of psychological distress experienced by SWs will benefit not only themselves, but also their families and colleagues, as well as their clients. Moreover, this has potential benefits for the social work profession and for the general community.  相似文献   
998.
黄蔓雯  蒋明 《民族学刊》2021,12(12):71-80, 131
构建相互嵌入式社会结构和社区环境,是铸牢中华民族共同体意识,推动多民族社区治理的重要途径。由于多元文化的碰撞交融,社区内部张力扩大,民族互嵌式社区的治理在一定程度上存在着多民族融合表面化、社区共同体意识淡薄等一系列问题。论文结合社会系统论、社区治理论的相关原理,厘清民族互嵌式社区的内涵,提出民族互嵌式社区居民公共服务幸福感指标体系的构想。通过差异化选址、探索性因素分析,形成影响居民公共服务幸福感的社区融合、社区治理、社区文化建设、社会医疗、社区教育五个维度及指标体系,为有效评价民族互嵌式社区公共服务提供借鉴。  相似文献   
999.
This paper presents a nonlinear state space model with considering a first-order autoregressive model for measurement noises. A recursive method using Taylor series based approximations for filtering, prediction and smoothing problem of hidden states from the noisy observations is designed. Also, an expectation-maximization algorithm for calculating the maximum likelihood estimators of parameters is presented. The closed form solutions are obtained for estimating of the hidden states and the unknown parameters. Finally, the performance of the designed methods are verified in a simulation study.  相似文献   
1000.
《Risk analysis》2018,38(2):357-375
In the aftermath of the A/H1N1 pandemic, health authorities were criticized for failures in crisis communication efforts, and the media were accused of amplifying the pandemic. Considering these criticisms, A/H1N1 provides a suitable case for examining risk amplification processes that may occur in the transfer of information from press releases to print news media during a health crisis. We integrated the social amplification of risk framework with theories of news decisions (news values, framing) in an attempt to contribute to existing research both theoretically and empirically. We conducted a quantitative content analysis of press releases disseminated by health and governmental authorities, as well as the quality and tabloid press in 10 European countries between March 2009 and March 2011. Altogether 243 press releases, 1,243 quality press articles, and 834 tabloid press articles were coded. Consistent with research on news values and framing the results suggest that quality and tabloid papers alike amplified A/H1N1 risks by emphasizing conflict and damage, presenting information in a more dramatized way, and using risk‐amplifying frames to a greater extent and risk‐attenuating frames to a lesser extent than press releases. To some extent, the quality and tabloid press differed in how risk information was presented. While tabloid press articles seemed to follow the leading quality press with regards to content and framing of health crisis coverage, they exhibited a stronger emphasis on drama and emotion in the way they presented information.  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