全文获取类型
收费全文 | 904篇 |
免费 | 62篇 |
专业分类
各国政治 | 57篇 |
工人农民 | 77篇 |
世界政治 | 193篇 |
外交国际关系 | 72篇 |
法律 | 407篇 |
中国政治 | 13篇 |
政治理论 | 142篇 |
综合类 | 5篇 |
出版年
2023年 | 17篇 |
2022年 | 6篇 |
2021年 | 12篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 48篇 |
2017年 | 56篇 |
2016年 | 51篇 |
2015年 | 39篇 |
2014年 | 33篇 |
2013年 | 105篇 |
2012年 | 52篇 |
2011年 | 34篇 |
2010年 | 44篇 |
2009年 | 31篇 |
2008年 | 42篇 |
2007年 | 50篇 |
2006年 | 47篇 |
2005年 | 38篇 |
2004年 | 25篇 |
2003年 | 18篇 |
2002年 | 32篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有966条查询结果,搜索用时 31 毫秒
21.
22.
The paper investigates party-union relationships in Italy (1946–2014) by hand-coding parties’ parliamentary speeches and trade unions’ congress motions. In line with the cartel party thesis, a time series analysis shows that the ideological closeness between the left-wing Italian General Confederation of Labour and left-wing parties deteriorated when the Italian Socialist Party (1980) and the heirs of the Italian Communist Party (1998) converged toward the centre of the ideological spectrum. Conversely, the closeness between the Catholic-inspired Italian Confederation of Workers’ Unions and the heirs of Christian Democracy increased after 1994, when the former party’s leftist factions became the major part of the Italian Popular Party. 相似文献
23.
Park Michael Choi Yoonsun Yoo Hyung Chol Yasui Miwa Takeuchi David 《Journal of youth and adolescence》2021,50(12):2374-2393
Journal of Youth and Adolescence - Asian Americans are simultaneously stereotyped as a perpetual foreigner and a model minority. This cross-sectional study of 308 Filipino American youth (mean age... 相似文献
24.
In this study we examined the role of psychological buffers (life satisfaction, self-esteem, perception of family cohesion, and perception of social support) in the development of hopelessness and suicidal ideation. The participants were 314 university students, 71 males and 243 females, who were asked to complete a battery of instruments measuring the psychological buffers mentioned above. The results of a set of hierarchical multiple regression analyses suggested that life satisfaction and self-esteem are independent predictors of lower levels of hopelessness, while perception of social support seems to be the major predictor of lower levels of suicidal ideation independent of depression and hopelessness severity. Thus, hopelessness seems to be minimized by the level of life satisfaction and level of self-esteem exhibited by the individuals, while the key factor to the mitigation of suicidal ideas seems to be perception of social support. 相似文献
25.
26.
27.
28.
29.
30.
Andrea Y. Garzón-Serrano M.Sc. César A. Sierra Ph.D. Oscar Rodríguez-Bejarano Dr.Sc. Diana Sinuco Dr.Sc. 《Journal of forensic sciences》2020,65(4):1085-1093
Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO. 相似文献