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   6190篇
  免费   470篇
  国内免费   34篇
管理学   113篇
劳动科学   1篇
民族学   76篇
人口学   357篇
丛书文集   343篇
理论方法论   699篇
综合类   2073篇
社会学   2023篇
统计学   1009篇
  2024年   30篇
  2023年   99篇
  2022年   59篇
  2021年   99篇
  2020年   153篇
  2019年   214篇
  2018年   255篇
  2017年   304篇
  2016年   236篇
  2015年   188篇
  2014年   300篇
  2013年   1189篇
  2012年   373篇
  2011年   264篇
  2010年   289篇
  2009年   282篇
  2008年   295篇
  2007年   308篇
  2006年   287篇
  2005年   273篇
  2004年   258篇
  2003年   220篇
  2002年   163篇
  2001年   174篇
  2000年   131篇
  1999年   56篇
  1998年   37篇
  1997年   35篇
  1996年   23篇
  1995年   18篇
  1994年   11篇
  1993年   16篇
  1992年   18篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   3篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   1篇
  1982年   2篇
  1980年   2篇
  1978年   1篇
排序方式: 共有6694条查询结果,搜索用时 46 毫秒
81.
基于发展新理念对粮食类家庭农场成长绩效的评价指标进行理论遴选后,借助专家评审和鉴别力分析进行指标筛选,构建了具有较高信度和效度的评价指标体系。以华北平原五省的453户粮食类家庭农场为样本,采用AHP-模糊综合评价模型,对指标体系做了应用研究。结果表明:粮食类家庭农场成长绩效虽在总体上处于中等偏上水平,但个体间存在一定的成长绩效差异;经济绩效整体表现良好,创新绩效却较低。因此,应引导粮食类家庭农场平衡性成长、制定精准扶持方略和建立成长绩效监测体系。  相似文献   
82.
新型农业经营主体的经营绩效关系到其可持续发展。采用农村固定观察点对我国各省区新型农业经营主体的调查数据,运用随机前沿分析法,对不同类型的经营主体的经营绩效进行分析,并进一步分析新型农业经营主体的差异性。结果表明:相比小农户而言,新型农业经营主体的经营绩效相对较高,但是其平均绩效还有很大的改善空间;新型农业经营主体面临融资难和人才缺乏的问题,且该问题在农民专业合作社中最为突出;我国家庭农场的经营绩效在三种新型农业经营主体中是最高的,其次是农业(龙头)企业,最后是农民专业合作社。对此,提出应完善土地“三权分置”机制,实现新型农业经营主体的规模化生产,进一步解决其融资难和人才缺乏的问题,加大政策扶持力度等建议。  相似文献   
83.
The Burr XII distribution offers a flexible alternative to the distributions that play important role for modelling data in reliability, risk and process capability. However, estimating the shape parameters of the Burr XII distribution is a challenging problem. The classical estimation methods such as maximum likelihood and least squares are often used to estimate the parameters of the Burr XII distribution, but these methods are very sensitive to the outliers in the data. Thus, a robust estimation method alternative to the classical methods is needed to find robust estimators that are less sensitive to the outliers in the data. The purpose of this paper is to use the optimal B-robust estimation method [Hampel FR, Ronchetti EM, Rousseeuw PJ, Stahel WA. Robust statistics: the approach based on influence functions. New York: Wiley; 1986] to obtain robust estimators for the shape parameters of the Burr XII distribution. The simulation results show that the optimal B-robust estimators generally outperform the classical estimators in terms of the bias and root mean square errors when there are outliers in data.  相似文献   
84.
Parenting interventions were an important feature of New Labour’s policies to combat social exclusion. This paper critically examines parenting programmes for families with adolescents, assessing national and local policy aims against the perspectives of women who took part in a parenting course, which was the subject of a local evaluation. The paper argues that, while there were important positive outcomes for the participants, the high levels of unmet need which women reported reflect important disparities between the aims of the intervention, the level of service provision, and the needs and concerns of mothers and grandmothers.  相似文献   
85.
Palliative care is specialized health care to improve quality of life for patients with serious illness and their families through prevention and relief of suffering. A Palliative Care Institute was held in western Washington to capture community voices about diverse needs, strengths, and opportunities for improvement of palliative care. Researchers employed qualitative methods to obtain thematic data, provide real-time analysis, and engage in a multivoting technique to reflect stakeholder interest in individual themes and prioritize larger group interests. Bronfenbrenner’s ecological systems framework was used to explore caregiver experiences. Within the microsystem, caregivers reported difficulties in interactions with medical providers as a key challenge. Within the mesosysytem, interactions between patients and medical providers and the impact on caregivers were explored. Within the exosystem, caregivers reported lack of control over the schedules of personal care staff. Macrosystem influences included impact of local culture on the development of palliative care services. Chronosystem influences include de-medicalization of childbirth and its impact on perceptions of palliative care. Implications include the need for social workers to be proactive in fostering trust and effective communication between care providers and caregivers, and the demand for health care provider training in communication with patients and families.  相似文献   
86.
This paper contains an application of the asymptotic expansion of a pFp() function to a problem encountered in econometrics. In particular we consider an approximation of the distribution function of the limited information maximum likelihood (LIML) identifiability test statistic using the method of moments. An expression for the Sth order asymptotic approximation of the moments of the LIML identifiability test statistic is derived and tabulated. The exact distribution function of the test statistic is approximated by a member of the class of F (variance ratio) distribution functions having the same first two integer moments. Some tabulations of the approximating distribution function are included.  相似文献   
87.
We study nonlinear least-squares problem that can be transformed to linear problem by change of variables. We derive a general formula for the statistically optimal weights and prove that the resulting linear regression gives an optimal estimate (which satisfies an analogue of the Rao-Cramer lower bound) in the limit of small noise.  相似文献   
88.
中国封建社会伦理之中,积淀了丰富的以"尊亲"、"顺亲"、"养亲"等为主要内容的父子伦理精义;在中国社会结构由金字塔型演变为橄榄型、步入了后喻社会时代的今天,封建社会时代形成的许多父子伦理内容和沟通模式已不适合当今社会时代的发展要求。在今日中国社会伦理系统之中,应该建立新型的父子伦利(互利)关系。这既需要借鉴现代社会的"互喻"模式,又要采补传统伦理的精髓内容。  相似文献   
89.
北宋东莱吕氏家族既与宰辅大族联姻,也选择有发展前景的新进士为婿或姻家,从而形成了一个个盘根错节的庞大政治集团,藉此长期维持其家族的社会地位和政治利益,并对北宋政治产生重大影响。  相似文献   
90.
Outlier detection algorithms are intimately connected with robust statistics that down‐weight some observations to zero. We define a number of outlier detection algorithms related to the Huber‐skip and least trimmed squares estimators, including the one‐step Huber‐skip estimator and the forward search. Next, we review a recently developed asymptotic theory of these. Finally, we analyse the gauge, the fraction of wrongly detected outliers, for a number of outlier detection algorithms and establish an asymptotic normal and a Poisson theory for the gauge.  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