全文获取类型
收费全文 | 18352篇 |
免费 | 425篇 |
专业分类
管理学 | 2687篇 |
民族学 | 78篇 |
人才学 | 1篇 |
人口学 | 1854篇 |
丛书文集 | 85篇 |
教育普及 | 1篇 |
理论方法论 | 1513篇 |
现状及发展 | 1篇 |
综合类 | 230篇 |
社会学 | 8347篇 |
统计学 | 3980篇 |
出版年
2023年 | 111篇 |
2020年 | 266篇 |
2019年 | 359篇 |
2018年 | 459篇 |
2017年 | 593篇 |
2016年 | 459篇 |
2015年 | 303篇 |
2014年 | 417篇 |
2013年 | 3135篇 |
2012年 | 605篇 |
2011年 | 541篇 |
2010年 | 425篇 |
2009年 | 403篇 |
2008年 | 416篇 |
2007年 | 436篇 |
2006年 | 388篇 |
2005年 | 403篇 |
2004年 | 364篇 |
2003年 | 341篇 |
2002年 | 380篇 |
2001年 | 454篇 |
2000年 | 448篇 |
1999年 | 414篇 |
1998年 | 294篇 |
1997年 | 284篇 |
1996年 | 278篇 |
1995年 | 260篇 |
1994年 | 229篇 |
1993年 | 240篇 |
1992年 | 299篇 |
1991年 | 252篇 |
1990年 | 264篇 |
1989年 | 279篇 |
1988年 | 239篇 |
1987年 | 219篇 |
1986年 | 231篇 |
1985年 | 264篇 |
1984年 | 268篇 |
1983年 | 269篇 |
1982年 | 211篇 |
1981年 | 187篇 |
1980年 | 181篇 |
1979年 | 225篇 |
1978年 | 170篇 |
1977年 | 161篇 |
1976年 | 150篇 |
1975年 | 139篇 |
1974年 | 130篇 |
1973年 | 123篇 |
1971年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
931.
In this article we discuss various strategies for constructing bivariate Kumaraswamy distributions. As alternatives to the Nadarajah et al. (2011) bivariate model, four different models are introduced utilizing a conditional specification approach, a conditional survival function approach, and an Arnold–Ng bivariate beta distribution construction approach. Distributional properties for such bivariate distributions are investigated. Parameter estimation strategies for the models are discussed, as are the consequences of fitting two of the models to a particular data set involving the proportion of foggy days at two different airports in Colombia. 相似文献
932.
It is well known that in finance variances and covariances of asset returns move together over time. Recently, much interest has been aroused by an approach involving the use of the realized covariance (RCOV) matrix constructed from high-frequency returns as the ex-post realization of the covariance matrix of low-frequency returns. For the analysis of dynamics of RCOV matrices, we propose the generalized conditional autoregressive Wishart (GCAW) model. Both the noncentrality matrix and scale matrix of the Wishart distribution are driven by the lagged values of RCOV matrices, and represent two different sources of dynamics, respectively. The GCAW is a generalization of the existing models, and accounts for symmetry and positive definiteness of RCOV matrices without imposing any parametric restriction. Some important properties such as conditional moments, unconditional moments, and stationarity are discussed. Empirical examples including sequences of daily RCOV matrices from the New York Stock Exchange illustrate that our model outperforms the existing models in terms of model fitting and forecasting. 相似文献
933.
Zdeněk Hlávka Marie Hušková Claudia Kirch Simos G. Meintanis 《Econometric Reviews》2017,36(4):468-492
We develop testing procedures which detect if the observed time series is a martingale difference sequence. Furthermore, tests are developed that detect change–points in the conditional expectation of the series given its past. The test statistics are formulated following the approach of Fourier–type conditional expectations first proposed by Bierens (1982) and have the advantage of computational simplicity. The limit behavior of the test statistics is investigated under the null hypothesis as well as under alternatives. Since the asymptotic null distribution contains unknown parameters, a bootstrap procedure is proposed in order to actually perform the test. The performance of the bootstrap version of the test is compared in finite samples with other methods for the same problem. A real–data application is also included. 相似文献
934.
The paper entitled “Bivariate and Multivariate Normal Characterizations: A Brief Survey,” by Hamedani, which was published in 1992, covered the published characterizations of bivariate and multivariate normal (MVN) distributions from 1941 to 1991. The present work is a follow-up to the 1991/1992 survey which includes not only characterizations of the bivariate and MVN distributions, but also characterizations of the matrix variate normal distribution, which have appeared from 1991/1992 to the present. 相似文献
935.
Arthur C. Nielsen 《Journal of marital and family therapy》2017,43(4):685-699
This essay reviews the most significant contributions of psychodynamic thought to the field of couple therapy. It distills the work of numerous clinicians and researchers who, though writing from diverse perspectives, share fundamental assumptions and concerns. Rather than emphasizing differences between schools of thought, this paper mines their best contributions in a discussion of five central therapeutic targets: underlying issues, divergent subjective experiences, transferences, projective identification, and acceptance. Two detailed cases illustrate the benefits and techniques for targeting these five therapeutic domains. Video Abstract is found in the online version of the article . 相似文献
936.
Evrim Gülbetekin Seda Bayraktar Özlenen Özkan Ömer Özkan 《Journal of Nonverbal Behavior》2017,41(4):325-343
One of the most prevalent problems in face transplant patients is an inability to generate facial expression of emotions. The purpose of this study was to measure the subjective recognition of patients’ emotional expressions by other people. We examined facial expression of six emotions in two facial transplant patients (patient A = partial, patient B = full) and one healthy control using video clips to evoke emotions. We recorded target subjects’ facial expressions with a video camera while they were watching the clips. These were then shown to a panel of 130 viewers and rated in terms of degree of emotional expressiveness on a 7-point Likert scale. The scores for emotional expressiveness were higher for the healthy control than they were for patients A and B, and these varied as a function of emotion. The most recognizable emotion was happiness. The least recognizable emotions in Patient A were fear, surprise, and anger. The expressions of Patient B scored lower than those of Patient A and the healthy control. The findings show that partial and full-face transplant patients may have difficulties in generating facial expression of emotions even if they can feel those emotions, and different parts of the face seem to play critical roles in different emotional expressions. 相似文献
937.
Cameryn C. Garrett Belinda Hewitt Danielle C. Newton Anne M. Kavanagh 《Australian Social Work》2017,70(1):54-65
The year 2014 marked the abolition of the Baby Bonus and its replacement with a substantially reduced parenting payment. While often criticised as “middle-class welfare,” or publicly denounced due to its purported misuse by disadvantaged mothers, this paper argues that the Baby Bonus provided valuable financial assistance to families experiencing high financial stress. To investigate young women's experience of receiving the Baby Bonus, 19 semistructured interviews were conducted with young mothers in Melbourne who had recently had babies. Many were experiencing financial stress and this payment provided much needed financial support for the basic costs arising from having a baby. Several mothers perceived work as a luxury that was out of reach due to high childcare costs relative to their earning capacity and therefore saw Paid Parental Leave as a further privilege unavailable to them. Our results suggest that while the concerns of policymakers to achieve the best use of scarce resources are critical, it should also be acknowledged that the policy change may have serious implications for many young mothers and may exacerbate disadvantage, and young mothers’ sense of alienation, ultimately leading to greater inequalities. 相似文献
938.
Jesse J. Helton Jill C. Schreiber Barbara H. Fiese 《Child and Adolescent Social Work Journal》2017,34(2):159-169
Among their many responsibilities, foster parents are tasked with providing healthy food and proper nutrition to children with a variety of physical, psychological, and emotional needs. Using the lens of symbolic interactionism, this exploratory mixed methods study examined how foster parents attend to the nutritional needs of abused and neglected children. Methods used included both quantitative surveys and qualitative follow-up interviews. Surveys were completed by 23 foster parents in a large, Midwest metropolitan area. Parents reported they provided their children balanced meals, although one-third of households reported instances of food insecurity. During qualitative interviews, foster parents (N = 9) described how children arrived at their home with a variety of unhealthy eating habits, some severe in nature. Parents discussed strategies used to modify and improve eating patterns, including offering healthy food choices, having children plan meals, and gathering as a family for daily dinners. In general, parents understood the link between unhealthy eating and past childhood trauma, but also reported being unprepared for more serious eating problems like hoarding. Findings indicate that foster parents need food assistance to increase food security as well as training in assessing and responding a variety of unhealthy child eating behaviors. 相似文献
939.
Kamila Dvořáková Moé Kishida Jacinda Li Steriani Elavsky Patricia C. Broderick Mark R. Agrusti 《Journal of American college health : J of ACH》2017,65(4):259-267
Objective: Given the importance of developmental transitions on young adults' lives and the high rates of mental health issues among U.S. college students, first-year college students can be particularly vulnerable to stress and adversity. This pilot study evaluated the effectiveness and feasibility of mindfulness training aiming to promote first-year college students' health and wellbeing. Participants: 109 freshmen were recruited from residential halls (50% Caucasian, 66% female). Data collection was completed in November 2014. Methods: A randomized control trial was conducted utilizing the Learning to BREATHE (L2B) program, a universal mindfulness program adapted to match the developmental tasks of college transition. Results: Participation in the pilot intervention was associated with significant increase in students' life satisfaction, and significant decrease in depression and anxiety. Marginally significant decrease was found for sleep issues and alcohol consequences. Conclusions: Mindfulness-based programs may be an effective strategy to enhance a healthy transition into college. 相似文献
940.
Michelle L. Munro-Kramer Alexandra C. Dulin Caroline Gaither 《Journal of American college health : J of ACH》2017,65(5):297-305
Objective: Sexual assault is a pervasive crime on our college campuses and many survivors do not seek post-assault resources. This study will explore components of alternative interventions to consider in the development of campus-based interventions for sexual assault survivors. Participants: Three stakeholder groups including survivors (n = 8), healthcare providers (n = 6), and advocates (n = 19) were recruited from May 2014 to December 2014 from two university campus communities using flyers and purposive sampling. Methods: A qualitative study design utilized semi-structured interviews and semi-structured focus groups with survivors, healthcare providers, and advocates. Results: Five themes emerged to consider for future campus-based sexual assault interventions: (a) culture of caring, (b) one-stop shop, (c) validation, (d) survivor control and agency, and (e) confidentiality. Conclusions: Although accessible and effective options for post-assault care do currently exist, participants described alternative future interventions that were either (a) print materials or (b) technology-based. 相似文献