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   2600篇
  免费   44篇
各国政治   126篇
工人农民   62篇
世界政治   153篇
外交国际关系   66篇
法律   1916篇
中国政治   21篇
政治理论   283篇
综合类   17篇
  2020年   31篇
  2019年   22篇
  2018年   22篇
  2017年   33篇
  2016年   40篇
  2015年   23篇
  2014年   38篇
  2013年   187篇
  2012年   61篇
  2011年   68篇
  2010年   36篇
  2009年   35篇
  2008年   56篇
  2007年   71篇
  2006年   71篇
  2005年   74篇
  2004年   72篇
  2003年   70篇
  2002年   70篇
  2001年   156篇
  2000年   123篇
  1999年   76篇
  1998年   26篇
  1995年   18篇
  1994年   22篇
  1993年   21篇
  1992年   63篇
  1991年   69篇
  1990年   61篇
  1989年   84篇
  1988年   83篇
  1987年   72篇
  1986年   76篇
  1985年   65篇
  1984年   35篇
  1983年   41篇
  1982年   19篇
  1981年   30篇
  1979年   28篇
  1978年   21篇
  1977年   27篇
  1976年   19篇
  1975年   31篇
  1974年   30篇
  1973年   31篇
  1972年   32篇
  1971年   24篇
  1970年   20篇
  1969年   24篇
  1968年   20篇
排序方式: 共有2644条查询结果,搜索用时 46 毫秒
101.
Seize the moment     
Smith IK 《Time》2000,156(13):110
  相似文献   
102.
An intoxication following administration of morphine, tramadol and atracurium in a suicide case is reported. The route of administration and the amount of the particular drug were known from the investigation of the death scene and the findings of the postmortem examination. Tramadol was present in the gastric contents as well as in blood, liver, kidney and brain samples, whereas the drug could not be detected in muscle. All body fluids and tissues investigated contained morphine as well as its 3- and 6-glucuronides with the exception of muscle tissue. The concentrations of morphine and its glucuronide metabolites were determined by LC/MS following solid phase extraction. Interestingly, the concentration of M6G in brain, liver and kidney were close to the concentration of M3G in the particular tissue. This phenomenon might be explained by a preferential hydrolysis of M3G or by a preferential formation of M6G postmortem. Measurement of morphine and M6G in femoral blood and cerebrospinal fluid may be a useful indicator in rapid deaths.  相似文献   
103.
A blood group substance (BGS), a protein with ABH antigenic activity, was isolated from human seminal plasma and designated as p 84 (Sato, 1995). We have developed a method for determining the ABO blood type of semen by performing a sandwich enzyme-linked immunosorbent assay (ELISA) in which p 84 is captured with an anti-p 84 monoclonal antibody, and evaluated the specificity and sensitivity of this method. Although BGS activity was detected in semen sensitively by this method, it was not detected in saliva, urine, breast milk, blood or vaginal secretions. Since the concentration of p 84 in semen was independent of the secretion status, the status can be determined as non-secretor when p 84 but not BGS activity was detected. To determine the stability of BGS activity on p 84, dried stains of semen on filter paper were kept at 4, 26, and 37 degrees C for 8 months, 2 years and 1 month, respectively, and their BGS activities were examined. After 8 months at 4 degrees C, over 60% of the original BGS activity was recovered from the stain. The activity could be detected even from a square as small as 0.25 by 0.25 cm. After 1 month at 37 degrees C and 2 years at 26 degrees C, 31 and 20% of the BGS activity, respectively, still remained. It could be detected from the pieces of 1.0 by 1.0 cm and 0.5 by 0.5 cm squares, kept for 1 month at 37 degrees C and 2 years at 26 degrees C, respectively. Finally, semen was mixed with saliva or blood at varying volumetric ratios and used for the sources of dried stains. The BGS activity of p 84 could be detected in the stains until the ratio between semen and saliva or blood reached 1:4. We conclude that this sandwich ELISA offers a more sensitive and specific method for determining the ABO blood type of semen samples obtained from sexual assault victims than existing methods, such as the conventional absorption-elution and classical hemagglutination-inhibition tests.  相似文献   
104.
Allele frequencies for six DNA polymorphisms have been studied in a population sample from Cantabria (middle north Spain) using the polymerase chain reaction. The HLA-DQA1 locus was analyzed by the reverse dot-blot technique and the other five by polyacrylamide gel electrophoresis followed by silver staining. Six alleles were found for HLA-DQA1. 15 alleles for D1S80, 6 alleles for HUMTHO1 and HUMCSF1PO, 7 for HUMTPOX and 8 alleles for HUMVWA. The 21 repeat allele in HUMVWA had not previously been reported in a Spanish population. The genotype distributions met Hardy-Weinberg expectations for all the systems and some statistical parameters of forensic interest were calculated. Comparisons with other populations revealed significant differences for HLA-DQA1, HUMVWA and HUMTHO1, with interracial differences being more pronounced than between Spanish populations. The HUMVWA system showed the highest forensic efficiency of the six polymorphisms studied.  相似文献   
105.
This report contains the results of two population studies on the X chromosome STR HumHPRTB carried out in a Northern and a Southern region of Germany. The numbers of unrelated individuals were 443 and 335, respectively. Eight alleles (alleles 9 to 16) were found. In female individuals 29 different genotypes were encountered. In German populations the HumHPRTB STR was characterized by the following data: PIC = 0.750; HET = 0.769: MEC = 0.556. Allele distribution met the Hardy-Weinberg expectations. The Northern and Southern populations did not show any significant differences.  相似文献   
106.
The successive killing of three siblings by their biological mother at two-year intervals is described. The children were 367 days, 75 days and 3 years old. Although sudden infant death syndrome (SIDS) or interstitial pneumonia could not be ruled out as the cause of death in the two younger children, who were killed first, the third child exhibited discrete signs of violence in the mouth and throat area which were interpreted as proof of infanticide. All three children had petechiae of the skin of the face and throat, the upper thorax, the shoulders and the mucous membranes of the mouth. None of the children exhibited signs of a disease-related hemorrhagic tendency. After the mother was convicted of murdering the three-year-old boy by smothering in combination with compression of the thorax, she confessed to having killed the other two children in a similar manner. In the absence of hemostatic disease, the presence of petechiae of the skin extending over the entire drainage area of the Vena cava superior can be regarded as evidence of an increase in pressure in the thoracic cavity secondary to obstruction of the airways with simultaneous chest compression.  相似文献   
107.
108.
109.
AB0 antigens can be extracted from human bone tissue into aqueous solution during boiling and then identified by absorption elution test.  相似文献   
110.
A protocol for comparative analysis of heroin making use of chromatographic methods and infra-red spectroscopy is presented.  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