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   1493篇
  免费   54篇
各国政治   72篇
工人农民   73篇
世界政治   187篇
外交国际关系   92篇
法律   771篇
中国共产党   2篇
中国政治   14篇
政治理论   294篇
综合类   42篇
  2023年   10篇
  2022年   10篇
  2021年   13篇
  2020年   37篇
  2019年   47篇
  2018年   55篇
  2017年   64篇
  2016年   66篇
  2015年   45篇
  2014年   50篇
  2013年   230篇
  2012年   59篇
  2011年   59篇
  2010年   52篇
  2009年   45篇
  2008年   55篇
  2007年   48篇
  2006年   58篇
  2005年   61篇
  2004年   42篇
  2003年   48篇
  2002年   43篇
  2001年   39篇
  2000年   36篇
  1999年   18篇
  1998年   29篇
  1997年   16篇
  1996年   13篇
  1995年   17篇
  1994年   11篇
  1993年   13篇
  1992年   12篇
  1991年   7篇
  1990年   9篇
  1989年   13篇
  1988年   9篇
  1987年   6篇
  1986年   14篇
  1985年   5篇
  1984年   6篇
  1983年   9篇
  1982年   15篇
  1981年   6篇
  1980年   4篇
  1979年   4篇
  1978年   7篇
  1977年   5篇
  1976年   6篇
  1974年   5篇
  1967年   5篇
排序方式: 共有1547条查询结果,搜索用时 328 毫秒
51.
52.
This study explored the relative influence of adolescents' perceptions of their attachment relationships with their mothers, fathers, and friends on three measures of self-esteem. The sample consisted of 493 New Zealand adolescents ranging from 13 to 19 years of age. Two dimensions of the attachment relationship were assessed: the utilization of emotional support and proximity, and the quality of affect. The major findings were as follows: utilization of emotional support and proximity from mothers, fathers, and friends was minimally related to overall self-esteem, coping abilities, and social competence. The quality of affect toward mothers and fathers was significantly related only to social competence. These findings suggest that adolescent self-esteem is more strongly associated with the quality of affect toward parents and friends than with the utilization of these target figures for support or proximity. The notion that parents and friends may contribute to different facets of self-esteem is discussed.This research is based on the first author's doctoral dissertation at the University of Auckland.Received Ph.D. from the University of Auckland, Auckland, New Zealand. Research interests are adolescent development and the development of children's health beliefs and behaviors. To whom reprint requests should be addressed at School of Occupatinal Therapy, Private Bag 92006, Auckland Institute of Technology, Auckland 1020, New Zealand.Received Ph.D. from the University of Canterbury. Main interests are in life span developmental psychology, and the development of low birthweight babies.Received Ph.D. from the Australian National University. Interests lie within life span developmental psychology and early cognitive development.  相似文献   
53.
In this paper seven hypotheses to explain variation in central bank independence across countries are tested. The predictions based upon the theory that delegation of authority by politicians to the central bank is used as a commitment device are not supported: central bank independence is not higher the larger the employment motivated inflationary bias, the higher political instability or the larger the government debt. Central bank independence is positively related to historical inflation experience and negatively with political instability. We do only find limited support for the view that countries with a universal banking system and countries whose central banks do not regulate financial institutions have more independent central banks.  相似文献   
54.
55.
His many publications include Theories of Mass Communication; Understanding Mass Communication; Milestones in Mass Communication Research;and, with Otto N. Larsen, The Flow of Information.  相似文献   
56.
57.
A method for comparison of the relative age of ink entries written by the same ballpoint pen on documents stored in darkness is presented. Inks were extracted from the document and analyzed by HPLC (high performance liquid chromatography). On aging, changes in the chemical composition of the inks were noted. These changes were similar to those observed when inks were exposed to light or heat. The aging was followed by using ternary diagrams constructed for dyes generally present in blue-colored inks--Crystal Violet, Methyl Violet, and Tetramethyl Para Rosaniline. The procedure is applicable for relative dating of ink entries in diaries, notebooks, etc., where often several ink entries are written by the same ink. However, a prolonged exposure of the document to daylight and/or artificial light (light from fluorescent tubes) as well as to extensive heat will render the whole procedure inapplicable. An example of the use of the proposed method in casework is given.  相似文献   
58.
In a double-blind placebo controlled study on psychomotor skills important for car driving (Study 1), a 75 mg dose of +/- 3,4-methylenedioxymethamphetamine (MDMA) was administered orally to 12 healthy volunteers who were known to be recreational MDMA-users. Toxicokinetic data were gathered by analysis of blood, urine, oral fluid and sweat wipes collected during the first 5h after administration. Resultant plasma concentrations varied from 21 to 295 ng/ml, with an average peak concentration of 178 ng/ml observed between 2 and 4h after administration. MDA concentrations never exceeded 20 ng/ml. Corresponding MDMA concentrations in oral fluid, as measured with a specific LC-MS/MS method (which required only 50 microl of oral fluid), generally exceeded those in plasma and peaked at an average concentration of 1215 ng/ml. A substantial intra- and inter-subject variability was observed with this matrix, and values ranged from 50 to 6982 ng/ml MDMA. Somewhat surprisingly, even 4-5h after ingestion, the MDMA levels in sweat only averaged 25 ng/wipe. In addition to this controlled study, data were collected from 19 MDMA-users who participated in a driving simulator study (Study 2), comparing sober non-drug conditions with MDMA-only and multiple drug use conditions. In this particular study, urine samples were used for general drug screening and oral fluid was collected as an alternative to blood sampling. Analysis of oral fluid samples by LC-MS/MS revealed an average MDMA/MDEA concentration of 1121 ng/ml in the MDMA-only condition, with large inter-subject variability. This was also the case in the multiple drug condition, where generally, significantly higher concentrations of MDMA, MDEA and/or amphetamine were detected in the oral fluid samples. Urine screening revealed the presence of combinations such as MDMA, MDEA, amph, cannabis, cocaine, LSD and psilocine in the multiple-drug condition.  相似文献   
59.
Self-report questionnaires are frequently used in youth research, but doubt remains whether total anonymity affects the results. This study compared the responses of 704 mainly 16–17-year-old adolescents to self-report measures of various health indicators in 2 groups: anonymous and confidential collection. For most health indicators no significant differences were found. Perceived health, use of alcohol, and aggressive behavior (for boys) were reported significantly less frequently in the confidential group (small effect size). It appeared that pupils with high scores on social desirability do not respond differently at most health indicators in the 2 conditions. For most health characteristics, epidemiologically useful outcomes may be derived from confidential self-report measures, which are also valuable for detecting individual at-risk children. Similar studies in lower grades and other types of education should confirm the results.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Research Department, Municipal Health Service Rotterdam area. Major research interests include emotional and behavioral problems of adolescents, suicidal behavior, youth health care, monitoring.  相似文献   
60.
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