全文获取类型
收费全文 | 1981篇 |
免费 | 124篇 |
专业分类
管理学 | 260篇 |
民族学 | 20篇 |
人才学 | 1篇 |
人口学 | 202篇 |
丛书文集 | 14篇 |
理论方法论 | 288篇 |
综合类 | 21篇 |
社会学 | 1023篇 |
统计学 | 276篇 |
出版年
2024年 | 4篇 |
2023年 | 26篇 |
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 74篇 |
2019年 | 94篇 |
2018年 | 88篇 |
2017年 | 113篇 |
2016年 | 116篇 |
2015年 | 73篇 |
2014年 | 73篇 |
2013年 | 301篇 |
2012年 | 104篇 |
2011年 | 99篇 |
2010年 | 79篇 |
2009年 | 70篇 |
2008年 | 61篇 |
2007年 | 62篇 |
2006年 | 61篇 |
2005年 | 50篇 |
2004年 | 62篇 |
2003年 | 47篇 |
2002年 | 39篇 |
2001年 | 22篇 |
2000年 | 22篇 |
1999年 | 24篇 |
1998年 | 25篇 |
1997年 | 19篇 |
1996年 | 19篇 |
1995年 | 17篇 |
1994年 | 28篇 |
1993年 | 19篇 |
1992年 | 23篇 |
1991年 | 13篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1976年 | 7篇 |
1974年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有2105条查询结果,搜索用时 187 毫秒
871.
872.
Although the ecologic effects of acid rain have been widely reported, relatively little is known about the effects of acidic air pollution on human health. Some epidemiologic and animal studies suggest, however, that acidity is an important determinant of the respiratory health effects of aerosols. This paper reviews some of that evidence and discusses its implications for the design and analysis of epidemiologic studies. We contrast two types of exposure patterns: peak exposures associated with air pollution episodes, and chronic exposures resulting from persistently high levels of air pollutants. Recent work on the analysis of repeated categorical outcome variables provides new methods for the analysis of episode studies. Studies of long-term exposure require comparisons among population groups, and these comparisons can be subject to the design effects characteristic of multistage sample surveys. We examine the implications of these design effects for epidemiologic studies. Finally, the paper discusses the measurement errors induced by the use of outdoor measurements to quantify personal exposure to air pollutants. Recent work on methods for errors-in-variables problems may aid in assessing the effects of such errors on conventional analyses of air-pollution studies. 相似文献
873.
874.
Abstract A growing body of research lends support to opportunity theory and its variants, but has yet to focus systematically on a number of specific offenses and contexts. Typically, the more crimes and contexts to which a theory applies, the broader its scope and range, respectively, and thus generalizability. In this paper, we focus on agricultural crime victimization— including theft of farm equipment, crops, livestock, and chemicals—an offense that opportunity theory appears well‐situated to explain. Specifically, we examine whether key dimensions of the theory are empirically associated with the likelihood of victimization and also examine factors associated with farmers' use of guardianship measures. In contrast to much previous research, we combine multiple individual‐level measures of these dimensions. We conclude that the theory partially accounts for variation in agricultural crime victimization, depending on the type of crime, and that greater work is needed investigating how key dimensions of opportunity theory should be conceptualized and operationalized in rural contexts. The study's implications for theory and practice are discussed. 相似文献
875.
876.
877.
We do not believe that the T-group is a vital tool for refurbishing organizational life. We present theoretical reasons for believing that organizational training to improve organizational functioning must help participants to function more effectively as components of working bodies carrying out specific tasks in a particular job-setting. We present a sequence of three steps useful in interventions, drawing upon actual examples of interventions in schools. 相似文献
878.
879.
Daniel Coleman Yousceek Jeong Robert W. Keener 《Journal of statistical planning and inference》2004,120(1-2):137-153
Super-saturated designs in which the number of factors under investigation exceeds the number of experimental runs have been suggested for screening experiments initiated to identify important factors for future study. Most of the designs suggested in the literature are based on natural but ad hoc criteria. The “average s2” criteria introduced by Booth and Cox (Technometrics 4 (1962) 489) is a popular choice. Here, a decision theoretic approach is pursued leading to an optimality criterion based on misclassification probabilities in a Bayesian model. In certain cases, designs optimal under the average s2 criterion are also optimal for the new criterion. Necessary conditions for this to occur are presented. In addition, the new criterion often provides a strict preference between designs tied under the average s2 criterion, which is advantageous in numerical search as it reduces the number of local minima. 相似文献
880.