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   1482篇
  免费   92篇
各国政治   130篇
工人农民   82篇
世界政治   199篇
外交国际关系   105篇
法律   792篇
中国共产党   1篇
中国政治   3篇
政治理论   255篇
综合类   7篇
  2023年   20篇
  2022年   17篇
  2021年   34篇
  2020年   56篇
  2019年   64篇
  2018年   98篇
  2017年   88篇
  2016年   87篇
  2015年   54篇
  2014年   77篇
  2013年   231篇
  2012年   65篇
  2011年   53篇
  2010年   37篇
  2009年   31篇
  2008年   46篇
  2007年   45篇
  2006年   44篇
  2005年   42篇
  2004年   52篇
  2003年   40篇
  2002年   31篇
  2001年   37篇
  2000年   38篇
  1999年   13篇
  1998年   7篇
  1997年   9篇
  1996年   6篇
  1995年   5篇
  1994年   11篇
  1993年   8篇
  1992年   8篇
  1991年   11篇
  1990年   6篇
  1989年   7篇
  1988年   9篇
  1987年   8篇
  1986年   3篇
  1985年   7篇
  1982年   6篇
  1980年   5篇
  1979年   7篇
  1978年   5篇
  1977年   3篇
  1973年   8篇
  1972年   4篇
  1971年   7篇
  1967年   4篇
  1965年   4篇
  1963年   3篇
排序方式: 共有1574条查询结果,搜索用时 15 毫秒
241.
The objective was to investigate color change and surface damage in dental resin composites exposed to high temperatures over different time intervals for comparative purposes. Samples were prepared using two resins - Z100(R) (R1) and Charisma (R2), heated at the following temperatures: 200 degrees C, 400 degrees C, 600 degrees C, 1000 degrees C, for 15, 30 and 45 min (n = 104 for each resin sample). Color (DeltaE) and brightness (DeltaL) changes were analyzed by spectrophotometry using the CIE Lab system and surface changes by Scanning Electron Microscopy (SEM). R1 showed more intense color changes after heat exposure than R2. DeltaL values were found to be the best parameter for evaluation of light and color change. A biphasic pattern after thermal exposure was detected, from dark brown to light white. SEM showed more intense alterations in R2 than in R1. These results indicate that the parameters observed in both resins are useful as a guide in forensic analyses.  相似文献   
242.
Lamendin et al. (J Forensic Sci 1992;37:1373) developed a general technique to estimate age of adults at death using two dental features: periodontosis and translucency of the tooth root. Prince and Ubelaker (J Forensic Sci 2002;47:107) modified this method, creating a formula for each sex and for different ancestries, and obtained more precise age estimations. In the present study, the validity of each method was tested in 45 males and 34 females of Spanish Caucasian origin, and a novel formula, based on Prince and Ubelaker method, was specifically developed for a population of mixed racial origin (mestizo) from Colombia, and findings obtained were again compared with those yielded by Lamendin adult dental aging technique. The Prince and Ubelaker method proved more accurate than the Lamendin technique in the Spanish Caucasian population, and our Prince and Ubelaker-based formula was also more accurate than the Lamendin et al. In both populations, the Lamendin method showed a higher mean error in estimations of the age of youngest and oldest individuals. These findings confirm the need to create specific formulas for each human group in order to obtain more accurate age estimates.  相似文献   
243.
Abstract:  Nonpenetrating chest trauma with injury to the heart and aorta has become increasingly common, particularly as a result of rapid deceleration in high-speed vehicular accidents, over the past 2–3 decades. The high mortality rate of cardiac injuries and possible late onset complications make blunt cardiac injuries an important challenging point for legal medicine. One hundred and ninety cases with blunt cardiac injuries in a period of 3 years were analyzed retrospectively in terms of patterns of cardiac injury, survival times, and demographic profiles of the cases in this study.  相似文献   
244.
245.
The anti-corruption activity of the 1990s is characterized by the rise of new players, such as specialized anti-corruption bodies. Anti-corruption agencies (ACAs) are public bodies of a durable nature, with a specific mission to fight corruption and reducing the opportunity structures propitious for its occurrence in society through preventive and/or repressive measures. Independently of their format and powers, ACAs encounter various constraints to their mandate, which explains the meagre results obtained by some of them. This introductory paper tries to understand the rise, future, and implications of this new kind of “integrity warrior” and to locate them in the evolving doctrine of corruption control. The objective of this edited volume is to re-launch the debate on ACAs as the most innovative feature of the anti-corruption movement of the last two decades.  相似文献   
246.
This commentary on the stigmatization of people with mental illness explores social perceptions of them as dangerous and uncivilized. The authors discuss how the legal system suggests that these are people who should be ousted from the community while mental health professionals attempt to reiterate the fact that these individuals are simply human. The authors describe ways people with mental illness have been subjected to discrimination, ridicule, and humiliation. This commentary discusses multiple perspectives of mental illness, from past to present, and how those perspectives influenced social, legal, and psychological frameworks.  相似文献   
247.
Bite mark analysis in forensic dentistry presupposes that the human dentition is unique and that its characteristics can be transferred precisely to several materials. The aim of the present study was to register the frequency of missing anterior teeth in the Brazilian adult population, discussing its potential importance in bite mark analysis. Data from the Brazilian Oral Health Survey were used; 13,431 male and female individuals aged 35 to 44 were examined according to the criteria of the World Health Organization. The analysis of Poisson regression was performed in order to calculate the rating ratios and the respective confidence interval at 95%. A total of 13,431 adults participated in the study. Among male individuals, 2063 (47.00%) were dentate and 2036 (46.40%) had at least one missing tooth. Only 254 (5.83%) were totally edentulous. A significant number of males and females presented 6 missing teeth in the same dental arch, revealing the poor state of oral health of adult Brazilians. Missing teeth were more frequent in the upper dental arch than in the lower arch. In the upper dental arch, the incisor group (central and lateral) was missing the most. In the lower dental arch, however, a certain lack of homogeneity was observed among the different dental groups as regards missing teeth. White individuals presented a smaller proportion of missing teeth compared to the other ethnic groups. Females were 1.61 (CI 1.50–1.73) times more likely than males to present missing teeth. The absence of upper teeth and the presence of lower teeth were observed in 16.10% of the individuals. Further research should also include an analysis of different age groups. This would increase the potential of applying this kind of information to bite mark analysis.  相似文献   
248.
This article attempts to measure the direct costs that the terrorist attacks of 3/11 had on the economy of the region of Madrid. The evaluation has been made applying conservative criteria, and the results obtained have to be considered as minimum. The result indicates that the terrorist attacks caused a loss of nearly 212 million euros to the regional economy of Madrid, equivalent to 0.16 percent of the regional GDP (0.03 of the national GDP). This confirms that the immediate economic dimension of a terrorist attack such as the one of 3/11—apart from human catastrophic consequences—is relatively low.  相似文献   
249.
This intervention argues that Bromley's account of American power underplays some of the structural weaknesses in the US-made liberal order. These weaknesses are not principally the result of relative economic decline, but chiefly the product of a political insistence among US ruling classes in getting their own way (that is, for the immediate American interests to prevail) regardless of their longer-term socio-economic or political consequences. It is the quest for American primacy, not the pursuit of a liberal international order that is the chief driver of US external relations. Likewise it is the more volatile dynamics of class antagonism and alliances both within and outside the USA—not the rational calculation of states as Bromley suggests—that tend to determine the success or failure of American primacy. I flesh out these claims by looking successively at the ideology of post-war American Empire, the contradictions of its actual implementation and the forms of socio-economic and political instability it generates. Bromley's sanguine view of the future of liberal order, it is argued, is only persuasive with a very narrow, inter-statist conception of world order and one which therefore underestimates the social origins of geopolitical disorder.  相似文献   
250.
Traditional methods for bone pulverization typically generate heat, risking stability of DNA sample. SPEX? has developed cryogenic grinders which introduce liquid nitrogen to cool the sample and aid in the grinding process. In this study, the Freezer Mill 6970 EFM was used with two DNA extraction methods and routine downstream STR analysis procedures. DNA from as little as 0.1 g of bone powder was used to develop full STR profiles after freezer mill pulverization, and the method was reproducible. Further, no contamination was detected upon cleaning/reuse of the sample vials. There were no significant differences in DNA yield, STR alleles detected, or peak heights using the freezer mill as compared to traditional grinding, and successful DNA profiles were achieved from as low as 0.1 g of bone powder with this method. Overall, this work indicates that this cryogenic mill method may be used as a viable alternative to traditional tissue grinders.  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