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   3774篇
  免费   133篇
各国政治   131篇
工人农民   120篇
世界政治   231篇
外交国际关系   121篇
法律   2655篇
中国政治   35篇
政治理论   601篇
综合类   13篇
  2021年   27篇
  2020年   49篇
  2019年   52篇
  2018年   75篇
  2017年   90篇
  2016年   82篇
  2015年   67篇
  2014年   76篇
  2013年   278篇
  2012年   87篇
  2011年   111篇
  2010年   80篇
  2009年   87篇
  2008年   109篇
  2007年   84篇
  2006年   105篇
  2005年   88篇
  2004年   98篇
  2003年   95篇
  2002年   91篇
  2001年   186篇
  2000年   133篇
  1999年   104篇
  1998年   38篇
  1997年   47篇
  1996年   35篇
  1995年   49篇
  1994年   44篇
  1993年   54篇
  1992年   81篇
  1991年   86篇
  1990年   77篇
  1989年   63篇
  1988年   84篇
  1987年   81篇
  1986年   98篇
  1985年   108篇
  1984年   86篇
  1983年   80篇
  1982年   38篇
  1981年   36篇
  1979年   34篇
  1978年   32篇
  1975年   31篇
  1974年   45篇
  1973年   24篇
  1972年   27篇
  1971年   31篇
  1970年   30篇
  1968年   32篇
排序方式: 共有3907条查询结果,搜索用时 15 毫秒
291.
It has been suggested that inter-canine width plus 57% of the cumulative distance between the lateral aspect of the canines and the pupil centers can be used to estimate mouth width. Evidence also suggests that the distance between the medial irises approximates actual mouth width fairly well. However, these soft tissue prediction guidelines are limited because they rely on accurate medio-lateral positioning of the pupils within the orbits, for which no systematic empirical evidence appears to exist at this stage. It would, therefore, be more appropriate to use only known hard tissue landmarks in mouth width prediction. This study reports the results of using inter-canine width as a percentage of mouth width for its prediction. This method seems favorable in comparison to the other guidelines because it is as accurate, uses known hard tissue landmarks, and does not rely on assumptions concerning pupil location. Estimating mouth width by using the canines alone, therefore, seems the best guideline to use in facial approximation techniques, at least given knowledge existing at this stage.  相似文献   
292.
This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.  相似文献   
293.
294.
The results of extraction of 1,2- and 1,4-dihydroxybenzene from water solutions by the hydrophobic and hydrophilic organic solvents are described. The influence of an extragent nature and of a water-phase pH medium on an extraction degree is demonstrated. The repetition factor needed to extract a preset quantity of examined compounds is calculated.  相似文献   
295.
296.
The case study was based on the osteologic collection of the chair for anthropology, State Moscow University, including the male carpal bones (67) and female carpal bones (13), aged above 18 to 20. Four measurements were made according to Martin's scheme for metacarpal bones and finger phalanxes. A diagnostic method was worked out on the bases of the discriminative analysis, with such method enabling the remodeling of the ordinal localization of metacarpal bones as well as of main, medium and distal phalanxes. The maximally accurate classification was ensured for metacarpal bones, ranging from 81.5% to 100%; and the minimally accurate one was achieved for distal phalanxes, ranging from 20% to 95%. The discriminative analysis results were checked for distal phalanxes by Neklyudov's series (male--100, female--85); they were described according to 7 sizes. However, an attempt to enhance the accuracy of the classification of these phalanxes failed. The offered method should be applied in combination with the traditional anatomic-and-morphological method; besides, if possible, it is necessary to check the congruence of joint surfaces in the metacarpal interphalangeal joints.  相似文献   
297.
A possibility was studied to use the plaster copies of skulls in the forensic medical identification of personality by applying the craniofacial method. No dependence was found between the plaster casts and the moulding types. Differences between the same craniometric sizes in the skull and in its cast are of an incidental nature. Such incidental deviation is related with an accuracy of determining the localization of craniometric points and with an instrumental precision of measuring devices. The necessity is substantiated that, while making a craniofacial examination, it is necessary to mark all anthropometric points in the skull cast, with the original being a control. The use of a plaster skull cast is possible in those cases, when the burial of the remains must be done in full.  相似文献   
298.
299.
300.
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