全文获取类型
收费全文 | 19088篇 |
免费 | 133篇 |
专业分类
管理学 | 2725篇 |
民族学 | 134篇 |
人才学 | 1篇 |
人口学 | 3253篇 |
丛书文集 | 30篇 |
理论方法论 | 1223篇 |
综合类 | 388篇 |
社会学 | 8201篇 |
统计学 | 3266篇 |
出版年
2021年 | 46篇 |
2020年 | 131篇 |
2019年 | 175篇 |
2018年 | 1886篇 |
2017年 | 1937篇 |
2016年 | 1294篇 |
2015年 | 189篇 |
2014年 | 264篇 |
2013年 | 1529篇 |
2012年 | 584篇 |
2011年 | 1408篇 |
2010年 | 1231篇 |
2009年 | 973篇 |
2008年 | 988篇 |
2007年 | 1190篇 |
2006年 | 185篇 |
2005年 | 400篇 |
2004年 | 412篇 |
2003年 | 373篇 |
2002年 | 256篇 |
2001年 | 210篇 |
2000年 | 209篇 |
1999年 | 190篇 |
1998年 | 144篇 |
1997年 | 129篇 |
1996年 | 166篇 |
1995年 | 113篇 |
1994年 | 116篇 |
1993年 | 107篇 |
1992年 | 151篇 |
1991年 | 127篇 |
1990年 | 121篇 |
1989年 | 118篇 |
1988年 | 112篇 |
1987年 | 96篇 |
1986年 | 98篇 |
1985年 | 113篇 |
1984年 | 119篇 |
1983年 | 130篇 |
1982年 | 100篇 |
1981年 | 92篇 |
1980年 | 90篇 |
1979年 | 97篇 |
1978年 | 94篇 |
1977年 | 83篇 |
1976年 | 70篇 |
1975年 | 72篇 |
1974年 | 62篇 |
1973年 | 60篇 |
1971年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
Suzanne T. Ortega David R. Johnson Peter G. Beeson Betty J. Craft 《Rural sociology》1994,59(4):598-619
Abstract This paper examines rural/urban differences and trends in mental health during the farm crisis of the 1980s in a large panel sample from a midwestern state. A community research perspective, which attributes differences to life styles, culture, and community context, is contrasted with an economic stress perspective, which focuses on individual differences in economic circumstances as determinants of rural-urban differences in mental health. Survey samples from 1981, 1986, and 1989 are used to examine differences among seven categories of community type. Multiple regression analysis of the trend and panel data provide support for both the individual economic distress and community context models. 相似文献
33.
The problem of estimating the value of an x variable for a given proportion of an observed value of the y variable is consdered for a non-linear model. Asymptotic confidence limits are obtained and an application of the method is illustrated witreal data. 相似文献
34.
The present studies examined children's and adults' preferences for gender- or age-based categorization using similarity and inductive inference tasks. Four-year-olds, 6-year-olds, and adults looked at pictures of people and decided which of two was more like a target (similarity condition) or which shared a novel age- or gender-related property with the target (inference condition). Age or gender-based matches were possible. The results are consistent with previous findings that gender-based classification decreases with age. However, they also demonstrate that children use gender more for judging similarity than for making inferences about novel properties. Distinct patterns emerge from the two tasks: 6-year-olds and adults in both conditions categorize more by age than gender; 4-year-olds categorize by gender more than age in the similarity task, but by age more in the induction task. Only adults differentiated by property in the inference condition. These findings suggest that the salience of gender categories cannot entirely be attributed to their inductive potential. Gender has a salience beyond what would be predicted by its power for directing novel generalizations. 相似文献
35.
36.
This article presents the findings of a small scale qualitative study of user perspectives in the adolescent sexual aggression field. Twenty four service users who had received intervention from nine different specialist providers completed a structured questionnaire about their experiences of professional involvement. Both young people who had sexually abused and parents identified the kinds of professional intervention which they found useful, as well as practices that they experienced as unhelpful. Young people and their families alike were found to value supportive interventions which gave them an opportunity to gain insight into the nature of sexual abuse as well to address their own feelings about their problems. 相似文献
37.
We employ vector autoregressive techniques to determine the current state of the labor queue. Unemployment rate differentials
have narrowed in recent years, potentially due to a change in the queue ordering, though a tight labor market and a stable
queue would yield similar results. We find no evidence that the queue ordering has changed, which brings into question the
resiliency of gains made by minority groups. We employ the same techniques to reveal the state of the queue across geographic
regions and find that substantial differences exist across regions, implying variation in the relative labor force status
of demographic groups. 相似文献
38.
Stuart G. Baker Barnett S. Kramer 《Journal of the Royal Statistical Society. Series C, Applied statistics》2005,54(5):941-954
Summary. When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes. 相似文献
39.
Point processes are the stochastic models most suitable for describing physical phenomena that appear at irregularly spaced
times, such as the earthquakes. These processes are uniquely characterized by their conditional intensity, that is, by the
probability that an event will occur in the infinitesimal interval (t, t+Δt), given the history of the process up tot. The seismic phenomenon displays different behaviours on different time and size scales; in particular, the occurrence of
destructive shocks over some centuries in a seismogenic region may be explained by the elastic rebound theory. This theory
has inspired the so-called stress release models: their conditional intensity translates the idea that an earthquake produces
a sudden decrease in the amount of strain accumulated gradually over time along a fault, and the subsequent event occurs when
the stress exceeds the strength of the medium. This study has a double objective: the formulation of these models in the Bayesian
framework, and the assignment to each event of a mark, that is its magnitude, modelled through a distribution that depends
at timet on the stress level accumulated up to that instant. The resulting parameter space is constrained and dependent on the data,
complicating Bayesian computation and analysis. We have resorted to Monte Carlo methods to solve these problems. 相似文献
40.