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   25865篇
  免费   771篇
各国政治   1066篇
工人农民   996篇
世界政治   2054篇
外交国际关系   878篇
法律   15566篇
中国共产党   2篇
中国政治   134篇
政治理论   5685篇
综合类   255篇
  2020年   302篇
  2019年   388篇
  2018年   499篇
  2017年   597篇
  2016年   616篇
  2015年   434篇
  2014年   502篇
  2013年   2539篇
  2012年   577篇
  2011年   657篇
  2010年   526篇
  2009年   610篇
  2008年   661篇
  2007年   685篇
  2006年   656篇
  2005年   596篇
  2004年   596篇
  2003年   624篇
  2002年   581篇
  2001年   1000篇
  2000年   890篇
  1999年   730篇
  1998年   425篇
  1997年   349篇
  1996年   324篇
  1995年   321篇
  1994年   353篇
  1993年   324篇
  1992年   513篇
  1991年   560篇
  1990年   519篇
  1989年   535篇
  1988年   502篇
  1987年   509篇
  1986年   554篇
  1985年   532篇
  1984年   471篇
  1983年   493篇
  1982年   370篇
  1981年   335篇
  1980年   278篇
  1979年   367篇
  1978年   223篇
  1977年   231篇
  1976年   208篇
  1975年   180篇
  1974年   206篇
  1973年   194篇
  1972年   169篇
  1971年   154篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Certified aircraft mechanics represent the largest gender-based demographic disparity in aviation with a 49-to-1 male-to-female ratio. Recent research into women’s perspective on the aircraft mechanic career field revealed that a large majority of women felt unsure or negatively about their potential promotion opportunities and social acceptance. The purpose of this follow-on mixed-methods concurrent triangulation study was to explore the perspectives of men regarding the aforementioned topics to see if they differ from previously published research on women perceptions. A total of 587 men and 431 women completed an eight-question survey containing 5-point Likert-type and open-ended questions. The quantitative comparison consisted of the total 1018 responses, while only the survey responses from the 587 men were analysed for correlations and qualitative codes. Results indicated that there was a significant difference between the perceptions of men from those of the women regarding work environment safety and social acceptance. Additional correlation analysis revealed social acceptance to be a key variable when predicting career appropriateness, advancement opportunity and work environment safety. The 587 qualitative responses yielded results that differed from those of women, citing an assumption that women have the same advancement opportunities or be as socially accepted as men entering the field.  相似文献   
952.
Latinx youth living in the United States reside in a myriad of cultural and neighborhood contexts, yet little is known regarding how cultural values influence behavior problems across neighborhood contexts. Using a person–environment fit framework, the present study explored the degree to which youth cultural values were associated with their externalizing problems, and the degree to which this association was shaped by their neighborhood’s socioeconomic status (SES), and Latinx and immigrant concentration. The sample comprised of 998 Latinx youth (Female?=?54.2%), ages 10 to 14 years old (Mage?=?11.8), from three large United States metropolitan areas. Multilevel modeling methods indicated that increased fit between youth cultural values and neighborhood Latinx and immigrant concentration was associated with fewer externalizing problems, but only in higher SES neighborhoods. The results support the importance of studying social determinants of Latinx youth behavioral health, and provide implications for both neighborhood-level and individual-level prevention and intervention programming.  相似文献   
953.
This paper explores the political field that has opened up in the wake of the recent civil war in Nepal. We focus on cultural-political developments in agrarian districts, where some of the most intriguing openings, and indeed the most pernicious closures, can be witnessed (as opposed to the national-state restructuring that commands more media and popular attention). Our research asks what spaces open up in the emerging political field at the district scale to entrench or transform dominant cultural codes and sedimented histories of socio-economic inequality. Preliminary research identifies specific sectors of local governance that have emerged as significant sites of struggle over the shape and meaning of ‘democracy’, namely forest management and infrastructure development. The primary contribution of the paper lies in specifying an analytical approach to the study of ‘post-conflict’ governance at the local scale via three conceptual terrains of inquiry – governance and planning, political subjectivity, and cultural politics. The ultimate objective is to develop a framework for assessing the conditions of possibility for a democratic restructuring of economy and society to accompany the official political institutions of liberal democracy.  相似文献   
954.
A breath alcohol profile is generated as a continuous function of time while a person is providing a breath sample. This paper describes a data acquisition system which samples breath alcohol concentrations at discrete intervals during exhalation. The data are stored on disk for later analysis. It is shown that the area under the profile curve for samples preceded by breath-holding is significantly larger than when breathing is normal prior to sample provision (p less than 0.001). The differences between the breath alcohol concentration measurements are also statistically significant (p less than 0.001) for the two different breathing patterns prior to breath exhalation. These results have physiological implications and suggest another means of evaluating breath alcohol profiles.  相似文献   
955.
This report describes a collaborative study on typing group-specific component (GC), conducted between the Central Research and Support Establishment and the forensic science laboratories of England, Wales and Northern Ireland. A population study (n=114) was performed. Fifty blood donors were selected to provide a distribution, slightly biased from normal, in favour of the GC 1F-1F and GC 1F-1S phenotypes. A protocol was devised for preparing large bloodstains. The strongest GC bands were obtained from the edge of a stain after the blood had been treated with K+/EDTA. Each laboratory received a representative portion of the large bloodstains for GC typing. Five of the eight laboratories correctly grouped all the bloodstains. No errors directly attitributable to the system were recorded in over 800 tests, indicating that GC in bloodstains can be typed reliably using the combination of isoelectric focusing in ultrathin narrow pH interval gels followed by immunofixation and silver staining.  相似文献   
956.
The isolation of spermatozoa from sexual assault swabs using proteinase K   总被引:1,自引:0,他引:1  
The most common examination in sexual offences is the identification of spermatozoa in aqueous extracts from swabs. Using Proteinase K with sodium dodecyl sulphate, it is possible to digest all the cellular material apart from the spermatozoa, resulting in a quick and effective method of their isolation. Spermatozoa were detected in 18 extracts using this treatment when the normal method had failed to reveal all but one of them.  相似文献   
957.
The microscopic pathology of the liver in fatal cocaine intoxication was studied. Data from cases of cocaine intoxication during the years 1981-1986 were collected and analysed. Thirty cases with a negative past history for intravenous drug abuse, and in which the terminal drug testing revealed solely cocaine or its metabolites, were compared with a control group of nineteen people who had died in motor vehicle accidents, with a terminal negative blood alcohol, negative drug screen and no history of drug abuse. A comparison of liver histology was made along with gross anatomical liver weight. These findings are compared to other studies of hepatotoxicity in drug abuse.  相似文献   
958.
A simple but rigorous approach is offered for evaluating the evidential value of single locus DNA autoradiographs. This approach does not use a binning technique and it does not treat alleles as discrete variables. Instead, the allele distribution is considered to be continuous. The variation between two comparable bands is assessed using previously determined experimental parameters. The Bayesian treatment leads to an expression of the "quality of a match".  相似文献   
959.
A study of deaths due to organophosphate and related "cholinesterase-inhibiting" pesticides was performed on the case files of the office of the Medical Examiner in Metropolitan Dade County in Miami, Florida, USA. Briefly, a comparison was performed between cases which occurred between the years 1961-1965, when such pesticides were used indiscriminately and before stricter laws regulating their use were enacted, and with a series of cases occurring between the years, 1981-85, after such stricter laws were enacted. The occurrence of such deaths dropped dramatically with the decease in organophosphate use. A discussion ensues, along with specific information for the reader, on how the forensic scientist may help ameliorate their environment.  相似文献   
960.
The eyes of fourteen fatally abused children and sixteen control cases were examined histopathologically. Ten of the abused children showed intraocular change. The most common ocular changes were subdural hemorrhage of the optic nerve and retinal hemorrhage which involved all the layers of the retina, but most commonly the nerve fiber layer, ganglion cell layer and inner nuclear layer. The presence of blood cavities within the retina partially supported the hypothesis of traumatic retinoschisis. The control cases of non-abused children rarely showed intraocular hemorrhage.  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