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   10980篇
  免费   306篇
各国政治   431篇
工人农民   389篇
世界政治   729篇
外交国际关系   303篇
法律   6959篇
中国政治   70篇
政治理论   2317篇
综合类   88篇
  2020年   104篇
  2019年   159篇
  2018年   197篇
  2017年   242篇
  2016年   224篇
  2015年   170篇
  2014年   189篇
  2013年   991篇
  2012年   227篇
  2011年   277篇
  2010年   231篇
  2009年   299篇
  2008年   298篇
  2007年   314篇
  2006年   276篇
  2005年   255篇
  2004年   244篇
  2003年   256篇
  2002年   242篇
  2001年   426篇
  2000年   373篇
  1999年   296篇
  1998年   160篇
  1997年   122篇
  1996年   140篇
  1995年   136篇
  1994年   135篇
  1993年   136篇
  1992年   236篇
  1991年   253篇
  1990年   245篇
  1989年   257篇
  1988年   229篇
  1987年   226篇
  1986年   265篇
  1985年   258篇
  1984年   235篇
  1983年   216篇
  1982年   153篇
  1981年   128篇
  1980年   115篇
  1979年   155篇
  1978年   90篇
  1977年   114篇
  1976年   98篇
  1975年   74篇
  1974年   90篇
  1973年   87篇
  1972年   78篇
  1971年   69篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
972.
973.
Nathan  Maehala R. 《Trusts & Trustees》2007,13(10):604-607
Trusts continue to play an important role in asset protectionplanning. But annuities and life insurance, and in particularSwiss annuities, are a viable alternative in many cases. Furthermore,the combination of both structures, in most cases can resultin benefits that go beyond that of a pure trust structure ora sole annuity. The mechanics of these advantages are examinedin this article.  相似文献   
974.
The authors compared arch width measurements of diagnostic dental models obtained from dental school patients. Arch width measurements were taken in the canine area on each dental cast in an effort to assist forensic dental investigators in matching certain classes of subjects to the bites they might possibly inflict. If any canine teeth were absent, the measurements were taken using other specified adjacent teeth which the investigators felt would be interpreted as the arch width determiners in a bite mark injury. The ages of the subjects varied from 14 to 87 years. Statistical comparison of the maxillary arch width, mandibular arch width, and the mean difference between maxillary and mandibular arch width were performed. Significant differences between the arch width measurements were found to exist between several classes of subjects based on race and sex.  相似文献   
975.
Autoerotic death. A definition   总被引:1,自引:0,他引:1  
A definition of autoerotic death is suggested that restricts the use of this term to accidental deaths that occur during individual, usually solitary, sexual activity in which a device, apparatus, or prop that was employed to enhance the sexual stimulation of the deceased in some way caused unintended death. The case of the autoerotic asphyxial death of a 48-year-old man is reported in order to demonstrate the application of this definition.  相似文献   
976.
Urgent problems of scientific research on medicolegal evaluation of vehicle trauma were studied. One of perspective ways of increasing scientific control and evidential value of expert conclusion is pointed out. Use of mathematical methods and personal computers in expert evaluation of vehicle trauma is recommended. Expert differential diagnostic system (impact-overrun) developed is described and operating condition of personal computer is given.  相似文献   
977.
978.
This model evaluates the use of dental stone casts derived from maxillary tissues and from the internal aspects of maxillary dentures for edentulous postmortem identification. Tissue topography of the total cast and of rugae tracings photographed from the casts were evaluated for identification accuracy in twenty-eight trials for each of the two designs. Eight casts were examined in each trial. The trial was designed as matching or nonmatching, and as an equivocal or unequivocal decision by the examiner. Unequivocal decisions with 100% accuracy resulted when the entire dental cast was evaluated. Seventy-nine percent accuracy with equivocation in some trials resulted when only rugae tracings from the casts were evaluated. This investigation supported use of stone casts derived from the internal anatomy of maxillary dentures for forensic science identification when cast topography in toto was considered.  相似文献   
979.
Abstract: A new screening method for detecting gamma-hydroxybutyric acid (GHB) in drink matrices, using the IonSense, Inc. (Saugus, MA) direct analysis in real time (DART) ion source coupled to a JEOL exact mass time-of-flight mass spectrometer (AccuTOF), was validated and compared with the current screening methodology. The DART ion source allows for analysis of samples under ambient conditions with little to no sample preparation. Fifty drink specimens were spiked at levels of 1, 2, 3, and 4 mg/mL GHB, and analyzed on the AccuTOF-DART. Positive detection of GHB occurred for each of the samples at each concentration level, giving 100% accuracy for the samples tested. Twenty-five of the 50 drink specimens were spiked at 1 mg/mL GHB and tested using a color test known as the GHB Color Test #3. Only two of these 25 specimens tested positive for the presence of GHB, giving only 8% accuracy. Implementation of this new methodology as a screening tool for GHB analysis will quickly eliminate negative specimens allowing the examiner to focus analysis time on those that screened positive.  相似文献   
980.
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