首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1495篇
  免费   103篇
各国政治   160篇
工人农民   109篇
世界政治   176篇
外交国际关系   78篇
法律   778篇
中国共产党   1篇
中国政治   8篇
政治理论   281篇
综合类   7篇
  2023年   24篇
  2022年   14篇
  2021年   37篇
  2020年   51篇
  2019年   61篇
  2018年   106篇
  2017年   125篇
  2016年   99篇
  2015年   72篇
  2014年   80篇
  2013年   232篇
  2012年   65篇
  2011年   62篇
  2010年   34篇
  2009年   22篇
  2008年   48篇
  2007年   48篇
  2006年   49篇
  2005年   53篇
  2004年   58篇
  2003年   57篇
  2002年   39篇
  2001年   35篇
  2000年   29篇
  1999年   11篇
  1998年   4篇
  1997年   8篇
  1996年   3篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   7篇
  1990年   3篇
  1989年   4篇
  1988年   5篇
  1987年   4篇
  1986年   2篇
  1985年   4篇
  1983年   2篇
  1982年   2篇
  1980年   3篇
  1977年   2篇
  1972年   3篇
  1968年   3篇
  1967年   6篇
  1966年   1篇
  1965年   1篇
  1964年   3篇
  1963年   2篇
排序方式: 共有1598条查询结果,搜索用时 15 毫秒
31.
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   
32.

The aim of this paper is to examine the influence of the right to information laws on sustainability transparency in European local governments. This goal is novel, in that previous studies have examined the effects of various factors on the dissemination of government information (demographic, socioeconomic, political and financial) but not the contribution of legal factors to online transparency on environmental, social and economic sustainability. Our research question is this: Do information laws contribute to transparency on sustainability? Using the Global Reporting Initiative guidelines and a statistical regression analysis, we studied the websites of 106 local governments in ten European countries. The results obtained show that when transparency laws clearly stipulate the rules applicable and the procedures established for appeals, exceptions, refusals and requests, this can favour transparency on environmental, social and economic sustainability. Our findings advance understanding of this field and reinforce the basis for legal reforms to enhance sustainability transparency.

  相似文献   
33.
34.
The article analyzes the relationship that exists between electoral campaigns and corruption, studying the case of Mexico. The most common ways and means of practicing and presenting corruption during these electoral processes are described. In addition, the circle of corruption that begins during the electoral processes and continues once in the government is described. In the same sense, the results of an opinion survey in the Metropolitan Zone of Guadalajara (ZMG) on corruption during electoral campaigns are presented. It is concluded that, many times, corruption in the government begins during the electoral stage, so it is important to articulate various strategies and legal instruments to inhibit it from the electoral stage.  相似文献   
35.
Motherhood is changing. An increasing number of women are deciding to remain childless, having fewer children, postponing their transition to motherhood, and simultaneously pursuing careers. These changes are deeply embedded in a reconfiguration of the times of motherhood. Although the intersection of motherhood and time has been widely acknowledged by gender and feminist studies, less attention has been paid to how in the making of motherhood women reproduce, negotiate and subvert time mandates and norms. This article aims to underscore the importance of time and how it relates to the enactment of motherhood in contemporary societies by analysing the planning, timing, sequencing, and simultaneity of the transition to motherhood in Chile. Through the analysis of 15 life story interviews with urban women from Santiago de Chile, this article addresses the intersection between social change, motherhood and time by showing how in the making of the transitions to motherhood women reproduce, negotiate and subvert traditional and emergent cultural mandates and social norms on the times of motherhood.  相似文献   
36.
Housework and childcare have been considered mechanisms for ‘doing gender’ through the allocation of different functions to women and to men. Women continue to devote more time and effort to this type of work, in spite of their progressive incorporation into the labour market. Same-sex couples escape this gender binarism, and so this study set out to learn the distribution criteria work, as well as the influence of gender socialization when it comes to establishing this distribution. A qualitative investigation was carried out with 21 Spanish same-sex families. The results indicate that the majority of couples position themselves in an egalitarian discourse based on the absence of differentiated gender roles and a low level of specialization. No differences were found between male and female couples. Nevertheless, the female couples show higher levels of discontent when the distribution was not egalitarian. In conclusion, it is proposed that the effects of gender socialization are perpetuated beyond heterosexual relationships and also affect same-sex couples.  相似文献   
37.
38.
Developing countries have suffered most of the financial crises in the context of the process of economic and financial globalisation. Both current and previous crises have revealed that unpredictability is a feature common to all the episodes which occurred during the process of globalisation. Although certain alarms went off, any of those external financial crises were actually predicted by the advanced methods in use for prediction and country risk analysis. Taking into consideration the information above, the aim of this paper is to check the ability to foresee external financial crises in developing countries of both the country risk index published by Euromoney and the Credit Ratings variable included therein. We have focused on the external financial crises that took place between 1992 and 2011, that is, in a full globalisation era. The results are negative. It appears that neither the index nor the sovereign ratings are able to reflect early enough the vulnerabilities that arise previously to the setting off the crisis episodes. This leads us to conclude that the existing models of country risk have limits. Thus, it would necessary to develop new instruments to measure this risk, considering uncertainty as an essential feature of the current economic and financial environment.  相似文献   
39.
Understanding the prevalence and correlates of decisional autonomy within specific cultural contexts is necessary to fully comprehend how family processes are embedded within culture. The goals of this study were to describe mothers’ and fathers’ decision-making with adolescents (M = 12.51 years, SD = 0.58; 51% female), including parent-unilateral, joint, and youth-unilateral decision-making, and to examine the socio-cultural and family characteristics associated with these different types of decision-making in 246 Mexican-origin families. Mothers reported more joint and youth-unilateral decision-making and less parent-unilateral decision-making than did fathers. Fathers reported more youth-unilateral decision-making with sons than with daughters. Further, for mothers, more traditional gender role attitudes and higher levels of mother-adolescent conflict were associated with more parent-unilateral and less joint decision-making. In contrast, for fathers, lower levels of respect values were associated with more youth-unilateral decision-making with sons, and higher levels of parent-adolescent warmth were associated with more youth-unilateral decision-making with daughters. The importance of understanding the different correlates of mothers’ and fathers’ decision-making with sons versus daughters is discussed.  相似文献   
40.
Mexican American youth are at greater risk of school failure than their peers. To identify factors that may contribute to academic success in this population, this study examined the prospective relationships from 5th grade to 7th grade of family (i.e., human capital [a parent with at least a high school education], residential stability, academically and occupationally positive family role models, and family structure) and individual characteristics (i.e., externalizing symptoms, bilingualism, gender, and immigrant status) to the academic performance of 749 Mexican American early adolescents (average age = 10.4 years and 48.7% were girls in 5th grade) from economically and culturally diverse families as these youth made the transition to junior high school. Results indicated that while controlling for prior academic performance, human capital and positive family role models assessed when adolescents were in 5th grade positively related to academic performance in 7th grade. Further, being a girl also was related to greater 7th grade academic success, whereas externalizing symptoms were negatively related to 7th grade academic performance. No other variables in the model were significantly and prospectively related to 7th grade academic performance. Implications for future research and interventions are discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号