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   18962篇
  免费   200篇
  国内免费   1篇
管理学   2812篇
民族学   134篇
人口学   3188篇
丛书文集   35篇
理论方法论   1113篇
综合类   440篇
社会学   8078篇
统计学   3363篇
  2023年   54篇
  2020年   144篇
  2019年   186篇
  2018年   1863篇
  2017年   1920篇
  2016年   1297篇
  2015年   201篇
  2014年   263篇
  2013年   1494篇
  2012年   618篇
  2011年   1364篇
  2010年   1211篇
  2009年   957篇
  2008年   979篇
  2007年   1175篇
  2006年   206篇
  2005年   421篇
  2004年   422篇
  2003年   368篇
  2002年   263篇
  2001年   230篇
  2000年   218篇
  1999年   184篇
  1998年   133篇
  1997年   131篇
  1996年   159篇
  1995年   110篇
  1994年   110篇
  1993年   98篇
  1992年   144篇
  1991年   124篇
  1990年   118篇
  1989年   114篇
  1988年   105篇
  1987年   91篇
  1986年   97篇
  1985年   111篇
  1984年   115篇
  1983年   127篇
  1982年   99篇
  1981年   89篇
  1980年   86篇
  1979年   95篇
  1978年   92篇
  1977年   81篇
  1976年   70篇
  1975年   70篇
  1974年   59篇
  1973年   63篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
361.
Most treatment for gambling disorder is provided on an outpatient basis. Only a small number of jurisdictions in North America provide higher levels of gambling treatment, such as residential or intensive outpatient (IOP) care, despite the potential need for these services. Further, there appear to be few guidelines for determining appropriate level of gambling treatment. The aim of the present study was to assess the appropriateness of higher levels of problem gambling care among clients receiving outpatient treatment. Problem gamblers and their therapists independently completed questionnaires that assessed the need and desire for residential and IOP treatment. About 42% of problem gambling outpatients noted that they would be “probably” or “definitely” willing to attend residential treatment, and about half indicated they would be equally likely to attend IOP. Therapists recommended about a third of their clients as appropriate for higher levels of care. For both client and therapist assessments, there was a significant association between desire or recommendation for level of treatment and severity of gambling and co-occurring problems. Further, therapist recommendations for level of care were significantly associated with client willingness to attend higher levels of treatment. Our data reveal the potential need for higher levels of care for problem gambling, as evaluated by clients and their therapists. Policy implications for the funding of residential and IOP treatment are discussed.  相似文献   
362.
This paper is about variable selection with the random forests algorithm in presence of correlated predictors. In high-dimensional regression or classification frameworks, variable selection is a difficult task, that becomes even more challenging in the presence of highly correlated predictors. Firstly we provide a theoretical study of the permutation importance measure for an additive regression model. This allows us to describe how the correlation between predictors impacts the permutation importance. Our results motivate the use of the recursive feature elimination (RFE) algorithm for variable selection in this context. This algorithm recursively eliminates the variables using permutation importance measure as a ranking criterion. Next various simulation experiments illustrate the efficiency of the RFE algorithm for selecting a small number of variables together with a good prediction error. Finally, this selection algorithm is tested on the Landsat Satellite data from the UCI Machine Learning Repository.  相似文献   
363.
The case study method has been essential in psychoanalysis and psychodynamic therapy, since it is the only way to describe and explore the deepest levels of the human psyche. Addiction is no more and no less than a particular psychological mechanism, identical at its core to other psychological compulsions, and is therefore best understood and reported by this method that explores the mind in depth. We will discuss the value of the case report method in general and in specific with regard to psychoanalysis and addiction, criticisms raised about this method, and comparisons of it with nomothetic research.  相似文献   
364.
Recent immigrants seldom join the ranks of volunteers for various social causes. Immigrants from former socialist countries have been shown to be particularly averse to organized forms of volunteering for reasons rooted in their past, including forced forms of collectivism imposed by the state. In this qualitative study, we explored the perceptions and practices of volunteering among ex-Soviet immigrants (mostly educated middle-aged women) who ran a project for the benefit of elderly. Our findings show that most volunteers chose causes targeting fellow immigrants, their resettlement and well-being, and were motivated by the wish to build co-ethnic support network and overcome marginalization in the Israeli society. Other volunteers were driven by the need for self-actualization in the context of underemployment and occupational downgrading. Personal empowerment and higher identification with the receiving society were the most salient outcomes of volunteering for our informants. We conclude that for some immigrants, volunteering can serve as a strategy of social integration.  相似文献   
365.
Civil Registration and Vital Statistics (CRVS) Systems are playing increasing roles in national and global data infrastructure, facilitating the achievement of key developmental goals. The performance of CRVS systems in many developing countries including Nigeria is sub optimal and information on their structure and operations scanty. This paper characterizes the statutory, institutional, and operational elements and social contexts of the Nigerian CRVS System. It includes a context analysis of the system and a review of improvement strategies and interventions. The paper shows that the Nigerian CRVS System is built on viable statutory and institutional platforms—the constitutional enshrinement of: universal, compulsory and continuous civil registration and, a central registration institution—the National Population Commission (NPC). NPC has registration hierarchy and infrastructure deployed at every level of political administration and mechanisms for efficient coordination of registration and production of vital statistics on live-births, deaths and stillbirths amongst other vital events. The major weaknesses of the system include inadequate financing and deployment of registration facilities, conflicting statutes and institutional arrangements for the registration of key events like death and stillbirths. Other weaknesses include intra-organizational conflicts in resource allocation and weak ICT infrastructure within the NPC. These are compounded by overarching contextual issues namely registration unfriendly sociocultural norms, weak national data infrastructure, systemic corruption, poverty and undeveloped civic culture. Domestic initiatives and interventions to improve the system have focused on birth registration, while multilateral interventions have only made a modest impact on the system. Thus, holistic in-country improvement initiatives supported with robust interventions are imperative to overcome weaknesses in the Nigerian CRVS system. However fundamental improvements in CRVS systems in developing countries like Nigeria may likely only follow sustainable solutions to overarching contextual issues especially poor infrastructure, weak institutions, poverty and systemic corruption.  相似文献   
366.
In this paper, Pitman closeness criterion is used to compare the nearness of record values and order statistics from two independent samples to a specific population quantile of the parent distribution while the underlying distributions are the same. General expressions for the associated Pitman closeness probability are obtained when the support of the parent distribution is bounded and also unbounded. Some distribution-free results are achieved for symmetric distributions. The exponential and uniform distributions are considered for illustrative proposes and exact expressions are obtained in each case.  相似文献   
367.
Inference of interaction networks represented by systems of differential equations is a challenging problem in many scientific disciplines. In the present article, we follow a semi-mechanistic modelling approach based on gradient matching. We investigate the extent to which key factors, including the kinetic model, statistical formulation and numerical methods, impact upon performance at network reconstruction. We emphasize general lessons for computational statisticians when faced with the challenge of model selection, and we assess the accuracy of various alternative paradigms, including recent widely applicable information criteria and different numerical procedures for approximating Bayes factors. We conduct the comparative evaluation with a novel inferential pipeline that systematically disambiguates confounding factors via an ANOVA scheme.  相似文献   
368.
We examine the effect of anomalous temperatures, rainfall levels, and monsoon timing on migration outcomes in Indonesia. Using panel data from the Indonesian Family Life Survey and high-resolution climate data, we assess whether intra- and inter-province moves are used as a response to climatic shocks. We evaluate the relative importance of temperature, rainfall, and monsoon timing for migration. Only temperature and monsoon timing have significant effects, and these do not operate in the direction commonly assumed. Estimated effects vary according to individuals’ gender, membership in a farm household, and location. We also analyze climate effects on sources of household income, which highlights the multi-phasic nature of household responses. Results undermine narratives of a uniform global migratory response to climate change and highlight the heterogeneous use of migration as a response to such changes. By extending previous research on environmentally induced migration in Indonesia, we also highlight the sensitivity of estimates to alternative climate and migration measures.  相似文献   
369.
Organizations are driven by continuous change. Global, socio-economic and technological megatrends – demographic changes and digitalization – are the reasons for transformation. Traditional organization forms are not in line with customers‘ need. Disruptive modes of development and innovations have been intensively discussed elsewhere. The topic of disruptive organization have not been discussed towards internal and external customer relations, although of high relevance. 129 Managers answered on communication ways and the purpose of upcoming meaning for the working place/office. Two new models and five concrete recommendations have been established for upcoming future organization.  相似文献   
370.
In this paper, proportion estimators and associated variance estimators are proposed for a binary variable with a concomitant variable based on modified ranked set sampling methods, which are extreme ranked set sampling (ERSS), median ranked set sampling (MRSS), percentile ranked set sampling (Per-RSS) and L ranked set sampling (LRSS) methods. The Monte Carlo simulation study is performed to compare the performance of the estimators based on bias, mean squared error, and relative efficiency for different levels of correlation coefficient, set and cycle sizes under normal and log-normal distributions. Moreover, the study is supported with real data application.  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