全文获取类型
收费全文 | 10634篇 |
免费 | 268篇 |
专业分类
各国政治 | 404篇 |
工人农民 | 379篇 |
世界政治 | 719篇 |
外交国际关系 | 286篇 |
法律 | 6733篇 |
中国政治 | 67篇 |
政治理论 | 2226篇 |
综合类 | 88篇 |
出版年
2020年 | 102篇 |
2019年 | 155篇 |
2018年 | 192篇 |
2017年 | 219篇 |
2016年 | 213篇 |
2015年 | 162篇 |
2014年 | 183篇 |
2013年 | 951篇 |
2012年 | 218篇 |
2011年 | 263篇 |
2010年 | 211篇 |
2009年 | 270篇 |
2008年 | 270篇 |
2007年 | 272篇 |
2006年 | 262篇 |
2005年 | 244篇 |
2004年 | 235篇 |
2003年 | 243篇 |
2002年 | 236篇 |
2001年 | 424篇 |
2000年 | 369篇 |
1999年 | 296篇 |
1998年 | 158篇 |
1997年 | 123篇 |
1996年 | 136篇 |
1995年 | 132篇 |
1994年 | 133篇 |
1993年 | 134篇 |
1992年 | 232篇 |
1991年 | 253篇 |
1990年 | 240篇 |
1989年 | 248篇 |
1988年 | 226篇 |
1987年 | 223篇 |
1986年 | 265篇 |
1985年 | 257篇 |
1984年 | 229篇 |
1983年 | 214篇 |
1982年 | 151篇 |
1981年 | 127篇 |
1980年 | 114篇 |
1979年 | 151篇 |
1978年 | 86篇 |
1977年 | 111篇 |
1976年 | 95篇 |
1975年 | 71篇 |
1974年 | 89篇 |
1973年 | 83篇 |
1972年 | 78篇 |
1971年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
971.
972.
973.
Abstract This paper analyses work, childcare, and earnings of mothers in the slums of Guatemala City and Accra. Similar factors affect decisions to work and to use formal daycare, but the importance of childcare varies with the role of the formal labour sector. In Guatemala, where formal sector work is important, higher prices for informal care increase formal daycare use. However, daycare prices and proximity to daycare centers do not significantly affect earnings in Guatemala City and Accra, respectively. Providing formal daycare may be more important to mothers' decision to work in cities where formal sector work dominates. 相似文献
974.
Gottfredson and Hirschi's (1990) A General Theory of Crime has sparked a great deal of theoretical debate and empirical investigation. Tests of the theory have focused on measuring the core element, the latent trait of self‐control. The majority of this research has used the 24‐item scale developed by Grasmick et al. (1993), and a great deal of attention has been directed at the validity of this scale. Empirical debate revolves around the unidimensionality of the scale as established using conventional factor analytic techniques [exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)]. In this paper, we provide the first application of an item response theory (IRT) Rasch model to the validation of the Grasmick et al. scale. IRT models focus on the interaction between the human subject and survey items, and the extent to which cumulative scales fail to provide fundamental measurement. Our results suggest that although conventional factor analyses yield results similar to those previously reported, IRT analysis reveals that one's level of self‐control influences self‐report responses, a finding consistent with Hirschi and Gottfredson. 相似文献
975.
目的探讨低氧、氧化应激中一氧化氮(NO)和氧自由基之间关系及其对培养神经元的损伤机理。方法对培养的新生大鼠神经细胞分别进行低氧、H2O2氧化应激处理和超氧化物歧化酶(SOD)抗氧化应激处理,用比色法等检测培养上清液中NO、丙二醛(MDA)、乳酸脱氢酶(LDH)和SOD含量变化指标。结果与对照组比较,低氧组和H2O2组的NO、LDH、MDA含量均显著增高,SOD含量显著降低,NO与SOD含量变化呈负相关关系。预先给予终浓度为200U/ml的SOD处理,可使神经细胞的NO、LDH和MDA释放量明显减少。各组间NO含量与LDH、MDA含量呈正相关关系。结论低氧、氧化应激促使神经元NO产生增多,NO有增加氧自由基对神经细胞的损伤作用。SOD具有清除氧自由基和减轻NO对神经元的损伤作用。 相似文献
976.
W. Michael Schuster R. Evan Davis Kourtenay Schley Julie Ravenscraft 《American Business Law Journal》2020,57(2):281-319
In this article we examine the rate at which patent applications are granted as a function of the inventor's race and gender. Empirical analysis of more than 3.9 million U.S. applications finds minority and women applicants are significantly less likely to secure a patent relative to the balance of inventors. Further analysis indicates that a portion of this bias is introduced during prosecution at the Patent Office, independent of the quality of the application. Mechanisms underlying these disparities are explored. The article concludes with a discussion of our results and their interaction with patent law, innovation policy, and employment trends. 相似文献
977.
American Journal of Criminal Justice - The harms crime victims experience extend far beyond the initial victimization and can have severe negative impacts on daily life. Using data collected via a... 相似文献
978.
Major disasters represent infrequent events that often require response organizations to vicariously learn from the experiences of others in order to improve their operations. A primary mechanism for such knowledge diffusion is the different practitioner and empirical journals for the organizational fields that comprise disaster response. A review of the literature for the law enforcement field, however, reveals that little attention is given to how these organizations manage actual disasters. In particular, the presentation of organizational experiences, whether through case studies or other methodologies, is very limited in the practitioner and empirical literature of this field. This represents a considerable problem for improvements of disaster response operations given that law enforcement agencies represent a key component in such efforts. The research presented in this article is an effort to fill this knowledge gap and thereby facilitate organizational learning to improve future law enforcement disaster response activities. The authors traveled to Mississippi and Louisiana after Hurricane Katrina to examine the response efforts of state and local law enforcement agencies to the storm. The findings from this research are reported here in a lessons‐learned format to inform law enforcement disaster response policy. 相似文献
979.
Thomas R. Johnson 《Regulation & Governance》2016,10(1):14-28
In China, urban middle class mobilization against potential pollution risk has become increasingly common. This article examines this phenomenon through a detailed case study of a 2009 anti‐waste incinerator campaign in the Panyu District of Guangzhou, which culminated in a sizeable public protest and government U‐turn. This episode revealed tension between the narrow, state‐centered regulatory model fixated on end‐of‐pipe pollution control, and a much broader decentered approach advocated – and practiced – by project opponents, which incorporated public consultation and much greater emphasis on upstream waste reduction and sorting. In the process, the Panyu campaign progressed beyond a case of “regulation by escalation,” whereby beneficial regulations are belatedly enforced following populist pressure. Instead, it transformed into an open dialogue between a plurality of actors, including citizens, journalists, experts, and officials, about what regulation should constitute and who should determine acceptable levels of risk. By focusing on the processes through which regulatory issues emerged and changed during the Panyu campaign, this article highlights the regulatory dynamism of environmental mobilization in a context of regulatory uncertainty, and campaigns against “locally unwanted land uses” more broadly. 相似文献
980.