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   523篇
  免费   42篇
  国内免费   5篇
管理学   58篇
民族学   7篇
人口学   16篇
丛书文集   28篇
理论方法论   29篇
综合类   283篇
社会学   50篇
统计学   99篇
  2024年   2篇
  2023年   6篇
  2022年   4篇
  2021年   10篇
  2020年   14篇
  2019年   11篇
  2018年   15篇
  2017年   14篇
  2016年   28篇
  2015年   23篇
  2014年   44篇
  2013年   65篇
  2012年   38篇
  2011年   38篇
  2010年   38篇
  2009年   25篇
  2008年   23篇
  2007年   28篇
  2006年   29篇
  2005年   24篇
  2004年   22篇
  2003年   17篇
  2002年   8篇
  2001年   9篇
  2000年   5篇
  1999年   1篇
  1998年   5篇
  1997年   7篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1990年   2篇
  1989年   1篇
  1987年   2篇
  1985年   1篇
  1984年   3篇
  1982年   1篇
排序方式: 共有570条查询结果,搜索用时 15 毫秒
1.
Keisuke Himoto 《Risk analysis》2020,40(6):1124-1138
Post-earthquake fires are high-consequence events with extensive damage potential. They are also low-frequency events, so their nature remains underinvestigated. One difficulty in modeling post-earthquake ignition probabilities is reducing the model uncertainty attributed to the scarce source data. The data scarcity problem has been resolved by pooling the data indiscriminately collected from multiple earthquakes. However, this approach neglects the inter-earthquake heterogeneity in the regional and seasonal characteristics, which is indispensable for risk assessment of future post-earthquake fires. Thus, the present study analyzes the post-earthquake ignition probabilities of five major earthquakes in Japan from 1995 to 2016 (1995 Kobe, 2003 Tokachi-oki, 2004 Niigata–Chuetsu, 2011 Tohoku, and 2016 Kumamoto earthquakes) by a hierarchical Bayesian approach. As the ignition causes of earthquakes share a certain commonality, common prior distributions were assigned to the parameters, and samples were drawn from the target posterior distribution of the parameters by a Markov chain Monte Carlo simulation. The results of the hierarchical model were comparatively analyzed with those of pooled and independent models. Although the pooled and hierarchical models were both robust in comparison with the independent model, the pooled model underestimated the ignition probabilities of earthquakes with few data samples. Among the tested models, the hierarchical model was least affected by the source-to-source variability in the data. The heterogeneity of post-earthquake ignitions with different regional and seasonal characteristics has long been desired in the modeling of post-earthquake ignition probabilities but has not been properly considered in the existing approaches. The presented hierarchical Bayesian approach provides a systematic and rational framework to effectively cope with this problem, which consequently enhances the statistical reliability and stability of estimating post-earthquake ignition probabilities.  相似文献   
2.
一种嵌入式GUI软件结构实现方案   总被引:3,自引:0,他引:3  
综合比较了嵌入式GUI的几种实现方式,结合嵌入式系统的特点,研究了嵌入式GUI中的关键技术,分析了嵌入式GUI与普通GUI系统的不同之处,提出一种通用的嵌入式图形用户界面系统的设计思想和体系结构,这种嵌入式GUI实现方案具有轻型、占用资源少、可剪裁等特点。  相似文献   
3.
在语言使用过程中,动结式逐渐被语法化成表示致使—结果的特定语法形式,被语法化了的不是具体的词汇单位,而是一种语法结构或构式,即任何两个没有语义关联的动词只要并列出现在一个句子里就会形成致使—结果的语义关系。动结式里的两个动词各自表示一个事件,每个事件都能表述为一个独立的句子,通过移位和融合等句法操作合并在一起,临时构成独立的动词单位,从而在句法上把分别表示不同事件的两个句子合并为一个,实现表达的简约性。因为题元指派首先在底层结构完成,而动结式是表层句法操作的结果,所以动结式的语义关系仍需回到合并前的两个句子里确认。这种追根溯源的底层结构解释,清晰地揭示了动结式表层所呈现的复杂的句法和语义关系,是一种对于动结式的句法派生和形成机制提出的全新看法。  相似文献   
4.
In view of the MENA increasing participation in multinational trials and the increasing number of national/regional trials, this article explores potential areas of pharmacovigilance, requiring reform and provides recommendations for building a robust safety reporting system. Regulatory silence on expedited reporting requirements creates confusion for local sites that are part of multinational trials. Not allowing waiver for serious adverse events that are protocol specified or are study endpoints, along with lack of emphasis on causality as reporting criteria, adds substantial burden of uninformative cases for regulatory review. Despite global focus on Development Safety Update Report, local regulators are not yet insistent on real-time update of a drug’s cumulative safety profile. Issues like reporting requirements for generic trials, pregnancy reporting and lenient timeline for death/life-threatening events need attention. Finally, the need to formulate an all-encompassing local pharmacovigilance guideline, in sync with global practice cannot be overemphasized.  相似文献   
5.
通过收集石油套管现场失效数据资料,以套管失效为顶事件建立了石油套管的故障树,该故障树共考虑了47个不同的基本事件。通过对套管故障树的分析,得到了套管失效故障树的一阶最小割集27个,二阶最小割集29个,四阶最小割集1个,确立了套管的主要失效形式为潜在损坏、套管挤毁、套管断裂及严重腐蚀,并提出了提高套管可靠性的措施。  相似文献   
6.
柴王军  赵岷 《城市观察》2012,(6):168-184
随着经济全球化飞速发展,大型体育赛事逐渐成为主办城市营销自己的重要载体和工具,但并非每个城市都适宜举办大型体育赛事,主办城市必须选择与自身发展相适宜的大型体育赛事。本文首先从城市选择大型体育赛事进行经济分析,剖析影响城市举办大型体育赛事的赛事因素和城市因素,最后系统研究中国城市选择大型体育赛事的非均衡发展战略,以及从城市群和各类城市两个角度详细分析我国城市大型体育赛事选择思路。  相似文献   
7.
In clinical trials, missing data commonly arise through nonadherence to the randomized treatment or to study procedure. For trials in which recurrent event endpoints are of interests, conventional analyses using the proportional intensity model or the count model assume that the data are missing at random, which cannot be tested using the observed data alone. Thus, sensitivity analyses are recommended. We implement the control‐based multiple imputation as sensitivity analyses for the recurrent event data. We model the recurrent event using a piecewise exponential proportional intensity model with frailty and sample the parameters from the posterior distribution. We impute the number of events after dropped out and correct the variance estimation using a bootstrap procedure. We apply the method to an application of sitagliptin study.  相似文献   
8.
We propose a typology of different meanings of cohabitation that combines cohabiters’ intentions to marry with a general attitude toward marriage, using competing risk analyses to examine whether some cohabiters are more prone than others to marry or to separate. Using data (N = 1,258) from four waves of the German Family Panel (PAIRFAM) and a supplementary study (DEMODIFF), we compared eastern and western German cohabiters of the birth cohorts 197173 and 198183. Western Germans more frequently view cohabitation as a step in the marriage process, whereas eastern Germans more often cohabit as an alternative to marriage. Taking into account marital attitudes reveals that cohabiters without marriage plans differ from those with plans in their relationship careers, and also shows that cohabiters who plan to marry despite holding a less favourable view of marriage are less likely to realize their plans than cohabiters whose intentions and attitudes are more congruent.  相似文献   
9.
Probabilistic risk assessment (PRA) is a useful tool to assess complex interconnected systems. This article leverages the capabilities of PRA tools developed for industrial and nuclear risk analysis in community resilience evaluations by modeling the food security of a community in terms of its built environment as an integrated system. To this end, we model the performance of Gilroy, CA, a moderate‐size town, with regard to disruptions in its food supply caused by a severe earthquake. The food retailers of Gilroy, along with the electrical power network, water network elements, and bridges are considered as components of a system. Fault and event trees are constructed to model the requirements for continuous food supply to community residents and are analyzed efficiently using binary decision diagrams (BDDs). The study also identifies shortcomings in approximate classical system analysis methods in assessing community resilience. Importance factors are utilized to rank the importance of various factors to the overall risk of food insecurity. Finally, the study considers the impact of various sources of uncertainties in the hazard modeling and performance of infrastructure on food security measures. The methodology can be applicable for any existing critical infrastructure system and has potential extensions to other hazards.  相似文献   
10.
The debate about the rise of civil society in Mexico suggests that the processes of political and economic liberalization are multiple and uneven and, thus, have different and contradictory effects on different social groups. This study takes such arguments into account and examines the nature of collective identities and social networks that are more likely to be mobilized in the rising civil society. Who, with what types of social networks and identities, are the active actors in this rising civil society in Mexico? This study also attempts to identify the central actors who take an active part in multi-sector coalitions. As such a broad coalition often leaves profound effects on politics and society, it is vital to ask which actors are likely to take an important step toward multi-sector coalition making. Using a catalog of 1797 protest campaigns collected from three Mexican newspapers between 1964 and 2000, event frequency analysis is employed to find active actors and social network analysis – blockmodel method and degree centrality measure – is applied to uncover central actors. The analyses reveal that while workers, peasants, or students continue to be very active, the centrality of these actors in contentious networks and coalitions has not increased. New central actors in the rising civil society turn out to be civic associations and NGOs formed around single issues, such as environment, retirement, and human rights. When a multi-sector coalition occurs in contemporary Mexico, NGOs and civic associations are likely to play a crucial role in it.  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