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   2920篇
  免费   184篇
各国政治   256篇
工人农民   216篇
世界政治   334篇
外交国际关系   192篇
法律   1519篇
中国共产党   1篇
中国政治   11篇
政治理论   559篇
综合类   16篇
  2024年   3篇
  2023年   37篇
  2022年   20篇
  2021年   51篇
  2020年   97篇
  2019年   126篇
  2018年   167篇
  2017年   189篇
  2016年   195篇
  2015年   120篇
  2014年   175篇
  2013年   520篇
  2012年   143篇
  2011年   138篇
  2010年   93篇
  2009年   80篇
  2008年   104篇
  2007年   118篇
  2006年   92篇
  2005年   79篇
  2004年   91篇
  2003年   86篇
  2002年   60篇
  2001年   38篇
  2000年   41篇
  1999年   23篇
  1998年   25篇
  1997年   15篇
  1996年   17篇
  1995年   25篇
  1994年   10篇
  1993年   16篇
  1992年   11篇
  1991年   13篇
  1990年   8篇
  1989年   5篇
  1988年   5篇
  1987年   11篇
  1986年   3篇
  1985年   6篇
  1984年   8篇
  1983年   4篇
  1982年   3篇
  1976年   3篇
  1974年   4篇
  1972年   4篇
  1970年   2篇
  1967年   3篇
  1966年   2篇
  1965年   3篇
排序方式: 共有3104条查询结果,搜索用时 15 毫秒
71.
Intravascular lymphoma (IVL) is a rare subtype of extranodal lymphomas that is characterized by the selective growth of neoplastic cells within the lumen of small vessels. Authors document the case of an unexpected death caused by an undiagnosed intravascular large B-cell lymphoma with multi-organ involvement, which had initially manifested as an infection and then as an unclarified central nervous system pathology. Histological examination showed a diffuse intravascular large B-cell brain lymphoma with prominent cerebral involvement. The relevance of the case report reveals the importance of an autopsy of an extremely rare and threatening pathology that in most cases is diagnosed only postmortem. As a result, the role of the forensic pathologist becomes particularly important. When specifically performing an in-depth autopsy evaluation with a specific histologic analysis, it is possible to identify the intravascular lymphoma and declare a more accurate cause of death.  相似文献   
72.
Many studies in the literature have highlighted the utility of virtual 3D databanks as a substitute for real skeletal collections and the important application of radiological records in personal identification. However, none have investigated the accuracy of virtual material compared to skeletal remains in nonmetric variant analysis using 3D models. The present study investigates the accuracy of 20 computed tomography (CT) 3D reconstruction models compared to the real crania, focusing on the quality of the reproduction of the real crania and the possibility to detect 29 dental/cranial morphological variations in 3D images. An interobserver analysis was performed to evaluate trait identification, number, position, and shape. Results demonstrate a false bone loss in 3D models in some cranial regions, specifically the maxillary and occipital bones in 85% and 20% of the samples. Additional analyses revealed several difficulties in the detection of cranial nonmetric traits in 3D models, resulting in incorrect identification in circa 70% of the traits. In particular, pitfalls included the detection of erroneous position, error in presence/absence rates, in number, and in shape. The lowest percentages of correct evaluations were found in traits localized in the lateral side of the cranium and for the infraorbital suture, mastoid foramen, and crenulation. The present study highlights important pitfalls in CT scan when compared with the real crania for nonmetric analysis. This may have crucial consequences in cases where 3D databanks are used as a source of reference population data for nonmetric traits and pathologies and during bone-CT comparisons for identification purposes.  相似文献   
73.
International Journal for the Semiotics of Law - Revue internationale de Sémiotique juridique - In the original publication of the article, the paragraph beginning “We begin with two...  相似文献   
74.
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   
75.
Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.  相似文献   
76.

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   
77.
78.
79.
The article seeks to reassess the traditional stereotype of the complex Balkan family, especially in Bulgaria, on the basis of published and unpublished materials. On most measure features, such as population structure, marriage patterns, fertility and mortality rates, family and household size and structure, and inheritance patterns the Balkans show a great deal of variety and, on some measures, are more like the western and central parts of Europe than the easter-part. But all attempts to argue for the historical predominance of the zadruga in southeastern Europe (and in Bulgaria in particular) are presumptious, because the zadruga has been firmly documented only for the period from the late eighteenth to the early twentieth century, when it was not statistically predominant. Its appearance (or recurrence) and decline could be explained by different factors, and almost promising area of exploration seems to be the possible connection between a stockbreeding economy and multiple families of the zadruga type.  相似文献   
80.
Although the Great Depression has been the subject of much research, focus normally centers on the impact instead of the tactics developed by working-class organizations to tackle the problems it caused, specifically unemployment. Recent research has sought to fill this gap, but numerous areas remain uncovered. This paper covers two of these: the situation in Spain and the reaction of anarcho-syndicalist union – the Confederación Nacional de Trabajo. Spain presents an anomalous case; a country that saw the replacement of a semi-fascist dictatorship by a democracy in the 1930s. Furthermore, the fact that the initial government of the Spanish Second Republic included the Socialists provides an opportunity of comparing and contrasting the positions and policies of reformist and revolutionary workers’ organizations. The study is based on predominantly on articles appearing in the CNT newspaper Solidaridad Obrera. The conclusion reached is that for the CNT rising unemployment was a symptom of an irreversible trend in a failing capitalist system, which could only be solved by the revolutionary overthrow of that system. Nonetheless, the union had to present plausible solutions to ameliorate the conditions of the workers to attract the unemployed and thus, create a force strong enough to lead that revolutionary change.  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