全文获取类型
收费全文 | 662篇 |
免费 | 25篇 |
国内免费 | 10篇 |
专业分类
管理学 | 80篇 |
民族学 | 4篇 |
人口学 | 56篇 |
丛书文集 | 38篇 |
理论方法论 | 11篇 |
综合类 | 357篇 |
社会学 | 45篇 |
统计学 | 106篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 23篇 |
2019年 | 12篇 |
2018年 | 12篇 |
2017年 | 26篇 |
2016年 | 15篇 |
2015年 | 29篇 |
2014年 | 33篇 |
2013年 | 97篇 |
2012年 | 37篇 |
2011年 | 34篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 55篇 |
2007年 | 37篇 |
2006年 | 36篇 |
2005年 | 22篇 |
2004年 | 16篇 |
2003年 | 19篇 |
2002年 | 16篇 |
2001年 | 25篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有697条查询结果,搜索用时 31 毫秒
41.
42.
基于Vague集和属性综合评价的股票投资价值分析方法 总被引:7,自引:0,他引:7
对二级市场上同一行业内的不同股票进行投资价值分析是一个系统综合评价问题。本文从评价指标的选择、单项指标的评价、多项指标的综合评价和属性识别准则四部分来阐述属性测度理论在股票投资价值分析中的应用。特别需要指出的是,股票投资价值评价指标体系的建立和指标权重的确定应用了Vague集的理论和方法。最后,我们应用属性综合评价方法对电子元器件制造业的公司股票进行投资价值分析,结果验证了该方法的实用性和正确性。 相似文献
43.
《Journal of American college health : J of ACH》2013,61(5):579-584
Objective: The authors assessed associations between body weight perception and weight loss strategies. Participants: They randomly selected male and female college students (N = 38,204). Methods: The authors conducted a secondary data analysis of the rates of weight loss strategies and body weight perception among students who completed the National College Health Assessment survey. Results: Half of respondents (50%) were trying to lose weight, although only 28% of students were overweight or obese. Also, 12% of respondents had inaccurate body weight perception. Women and men with inaccurate body weight perception were significantly more likely to engage in inappropriate weight loss strategies than were those with accurate body weight perception. Of all students attempting to lose weight, 38% used both diet and exercise. Conclusions: These data show that college students are interested in weight loss and that body weight perception plays an important role in the desire to lose weight. 相似文献
44.
财产保险火灾风险评价方法及其标准的制定在我国处于空白状态。根据安全系统工程学的思想,提出了基于财产保险的建筑火灾风险评价指标体系的建立方法,利用层次分析方法确定各指标的权重,并根据科学性和操作性的原则对指标的评价尺度进行了划分;在此基础上得出了建筑火灾风险综合分值评分表和核保和费率浮动方法。结果表明:利用层次分析方法确定各指标权重的方法是比较科学的,权重分布比较符合实际情况。结果显示:基于安全系统工程学思想的方法,可以为火灾保险国家标准的制定提供帮助。 相似文献
45.
Using exploratory data analysis, probability plots, scatterplots, and computer animations to rotate and visualize the data, we fit a trivariate Normal distribution to data for the height, the natural logarithm of body weight, and the body fat for 646 men between the ages of 50 and 80 years as reported by the medical staff of the U.S. Veterans Administration's “Normative Aging Study” in Boston, MA. Although these data do not include any children, women, or young men, the measurements represent the best data that we could find through a 4-year search. We believe that these data are well measured and reliable for men in the specified age range and that these data reveal an interesting statistical pattern for use in probabilistic PBPK models. 相似文献
46.
C.Y. Leung 《统计学通讯:理论与方法》2013,42(5):1659-1667
The performance of Anderson's classification statistic based on a post-stratified random sample is examined. It is assumed that the training sample is a random sample from a stratified population consisting of two strata with unknown stratum weights. The sample is first segregated into the two strata by post-stratification. The unknown parameters for each of the two populations are then estimated and used in the construction of the plug-in discriminant. Under this procedure, it is shown that additional estimation of the stratum weight will not seriously affect the performance of Anderson's classification statistic. Furthermore, our discriminant enjoys a much higher efficiency than the procedure based on an unclassified sample from a mixture of normals investigated by Ganesalingam and McLachlan (1978). 相似文献
47.
高梅芳 《江苏工业学院学报(社会科学版)》2000,(1)
提出了一种按温度比例因子设计低温双极晶体管的设计规则。在考虑双极晶体管低温效应的前提下,着重分析了双极晶体管发射区和基区的浓度及宽度在低温下的变化情况。结合按温度比例子变化后任何特定温度下的双极晶体管电流增益和截止频率的优化结果,给出了这些参数在按温度比例因子规则设计时温度比例因子的变化参数。 相似文献
48.
Sarah M. Bankoff PhD Sarah E. Valentine MA Michelle A. Jackson MA Rebecca L. Schacht PhD David W. Pantalone PhD 《Journal of American college health : J of ACH》2013,61(8):468-475
Abstract Objective: To examine correlates of compensatory weight control behaviors among women in transition between adolescence and adulthood. Participants: The authors recruited a sample of undergraduate women (N = 759) at a large northwestern university during the 2009–2010 academic year. Methods: Logistic regression was used to assess relations among childhood abuse, psychosocial functioning, adult dating relationship factors, and women's endorsement of compensatory weight control behaviors. Results: The final model reliably distinguished between participants who endorsed versus denied use of compensatory behaviors (χ2[5, N = 747] = 36.37, p < .001), with global psychosocial functioning and relationship avoidance accounting for the most variance. Conclusions: These findings illustrate the importance of considering childhood abuse histories and adult relationships while assessing young women's compensatory weight control behaviors. 相似文献
49.
毫米波高增益大功率收发组件研制 总被引:1,自引:0,他引:1
提出了一种可用于雷达的毫米波收发组件的实现方案。组件包括两个几乎完全相同的接收通道和一个发射通道,接收通道采用两次混频将毫米波信号变为50MHz中频,而发射通道则采用两次上变频将50MHz信号变为毫米波频段的信号发射出去。该文分析了收发组件的设计原理,讨论了组件方案选择,并给出了测试结果。收发组件的各项技术指标基本达到设计要求:在10MHz的工作带宽内,连续波发射功率达1W,接收机噪声系数小于4.5dB,接收通道的净增益超过100dB。 相似文献
50.
陈鹏 《华北电力大学学报(社会科学版)》2008,(6):95-99
在六朝的诸种文体之中,启文的骈化较晚,到刘宋时期才出现骈体之作。这一时期,启文也开始产生新变,出现了谢物小启。尤其到了梁代,谢物小启呈雨后春笋之势,不论是在数量上,还是在艺术成就上,都远远超过了用兼表奏的启文,并成为六朝后期四六化色彩很强的一种文体。 相似文献