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   5366篇
  免费   173篇
各国政治   187篇
工人农民   257篇
世界政治   391篇
外交国际关系   209篇
法律   3526篇
中国共产党   3篇
中国政治   26篇
政治理论   915篇
综合类   25篇
  2023年   42篇
  2021年   39篇
  2020年   75篇
  2019年   90篇
  2018年   135篇
  2017年   140篇
  2016年   157篇
  2015年   93篇
  2014年   118篇
  2013年   495篇
  2012年   143篇
  2011年   150篇
  2010年   108篇
  2009年   135篇
  2008年   140篇
  2007年   148篇
  2006年   147篇
  2005年   104篇
  2004年   130篇
  2003年   128篇
  2002年   112篇
  2001年   228篇
  2000年   217篇
  1999年   162篇
  1998年   62篇
  1997年   64篇
  1996年   58篇
  1995年   53篇
  1994年   60篇
  1993年   54篇
  1992年   122篇
  1991年   111篇
  1990年   138篇
  1989年   128篇
  1988年   140篇
  1987年   133篇
  1986年   100篇
  1985年   107篇
  1984年   83篇
  1983年   74篇
  1982年   52篇
  1981年   48篇
  1980年   40篇
  1979年   53篇
  1978年   37篇
  1976年   30篇
  1975年   29篇
  1974年   40篇
  1973年   35篇
  1971年   30篇
排序方式: 共有5539条查询结果,搜索用时 15 毫秒
951.
The analysis of expert certification on isolated hip fractures has shown that some experts make errors of underestimation of harm to the health basing on the criterion "duration of health impairment". How to prevent such errors and to improve quality of forensic medical certification is proposed. Such measures will raise social value of medical forensic expertise.  相似文献   
952.
It is shown that for verification of human sperm presence on the spots on material evidence it is feasible to apply solid phase enzyme immunoassay (EIA) with the kit "PSA-EIA-BEST T-8458" which is used in clinical practice for diagnosis of prostatic cancer and some other diseases. The method is specific and highly sensitive, convenient for objective registration and computer processing. It is also cost-effective and provides not only significant identification of sperm on the exhibits but also its human origin in complete absence of spermatozoa on the spot.  相似文献   
953.
The fetus is subjected to mechanical forces during labor and delivery, which may result in traumatic injuries. Such injuries include intracranial hemorrhage, spinal cord lesions, cephalhematoma, cranial or peripheral nerve palsies, intraabdominal organ rupture, or bony fractures. Risk for perinatal trauma and mortality is increased in primigravidas, multiple gestations, abnormal presentations, maternal-fetal disproportion, oligohydramnios, forceps or vacuum extractions, and internal version maneuvers. Very-low-birth-weight neonates (<1500 g) are at high risk due to ease of deformity of the cranium. Infants with certain congenital anomalies or pathologic processes that distort normal anatomy are also at increased risk, especially when a prenatal diagnosis is lacking. The authors present a case of a term gestation neonate who sustained a cervical spine dislocation fracture of C5-7, with subtotal transection of the spinal cord and resultant paralysis. The fetus was in vertex presentation, and a manual vaginal delivery was attempted. When the infant lodged in the birth canal following a difficult delivery of the head and arms, its enlarged abdomen was palpated, and the delivery was converted to an emergent cesarean section. The infant lived for 3 days and then expired due to neurologic complications of trauma sustained during the attempted vaginal delivery. Autopsy revealed a previously undiagnosed intraabdominal immature teratoma. The pathology of teratomas, the most common neonatal tumor and occasionally implicated in cases of birth trauma, will be addressed, followed by a review of the literature concerning birth trauma.  相似文献   
954.
We studied the trend in the number of forensic-medical examinations in trials against obstetricians and gynecologists conducted in Primorsky Region in 1997-2005. Most typical defects in obstetric-gynecological care are characterized. These cases are analysed in terms of forensic-medical practice. Detection and forensic-medical analysis of the above defects contribute to optimization of the diagnosis and treatment both in obstetric-gynecological practice and in wide medical practice.  相似文献   
955.
Prospective associations between violent victimization, the quality of the parent-adolescent relationship, and the subsequent onset of violent aggression were examined. Using the National Longitudinal Study of Adolescent Health (Add Health), participants were divided into violent and non-violent cohorts based on whether they had committed an act of violence prior to Wave 1. Results showed that violent victimization at Wave 1 predicted the onset of violent aggression at Wave 2 for adolescents who were non-violent at baseline. Earlier violent victimization, however, had no effect on aggression trajectories for baseline violent adolescents. Parent-adolescent relations functioned as a protective buffer, such that violently victimized adolescents who reported high quality relationships with parents were less likely to be involved in violent aggression at Wave 2. Subsequent gender interaction analyses revealed that while the buffering effect was evident for males, parent-adolescent relations did not protect females from the onset of aggressive behaviors. Findings are evaluated in light of social learning and cycle of violence theories that highlight the role of violent victimization among adolescents.
Jeffrey T. Cookston (Corresponding author)Email:
  相似文献   
956.
The accurate quantification of target DNA is an important step in the short tandem repeat analysis of forensic biological samples. By utilizing quantification data to control the amount of template DNA in the polymerase chain reaction (PCR), forensic scientists can optimize testing and minimize the consumption of limited samples. The ability to identify and quantify target DNA in mixed-species samples is crucial when it may be overwhelmed by nontarget DNA, as in cases of dog attack. We evaluated two quantitative real-time PCR assays for dynamic range, species specificity, and inhibition by humic acid. While both assays proved to be highly sensitive and discriminating, the Melanocortin-1 Receptor (MC1R) gene Taqman assay had the advantages of a shorter run time, greater efficiency, and safer reagents. In its application to forensic casework, the MC1R assay has been advantageous for quantifying dog DNA in a variety of mixed-species samples and facilitating the successful profiling of individual dogs.  相似文献   
957.
Diagnostic dilemma of sudden deaths due to acute hemorrhagic pancreatitis   总被引:1,自引:0,他引:1  
Sudden death due to acute pancreatitis has been rarely determined. A review of 3305 autopsies performed between 1991 and 2001 at the Council of Forensic Medicine found 12 cases (0.36%) with sudden death due to acute hemorrhagic pancreatitis without symptoms. A history of chronic alcohol ingestion was obtained from family in four cases (33%), and no stones were found in the bile ducts or in the gall bladders. During the autopsies, hemorrhage and edema were localized on the head of the pancreas in three cases and the whole pancreas in nine cases. The most common extrapancreatic pathology was found in the lung including pulmonary edema, alveolar hemorrhage, pleural effusion, and pulmonary congestion. There was no correlation between pulmonary and pancreatic damage. It is suggested that the forensic pathologists who are dealing with sudden unexpected death must not ignore the examination of pancreatic and extrapancreatic regions to avoid missing acute pancreatitis.  相似文献   
958.
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   
959.
Methods to estimate adult age from observations of skeletal elements are not very accurate and motivate the development of better methods. In this article, we test recently published method based on the acetabulum and Bayesian inference, developed using Coimbra collection (Portugal). In this study, to evaluate its utility in other populations, this methodology was applied to 394 specimens from four different documented Western European collections. Four strategies of analysis to estimate age were outlined: (a) each series separately; (b) on Lisbon collection, taken as a reference Coimbra collection; (c) on Barcelona collection, taken as a reference both Portuguese collections; and (d) on London collection taken as reference the three Iberian collections combined. Results indicate that estimates are accurate (83-100%). As might be expected, the least accurate estimates were obtained when the most distant collection was used as a reference. Observations of the fused acetabulum can be used to make accurate estimates of age for adults of any age, with less accurate estimates when a more distant reference collection is used.  相似文献   
960.
Abstract: Dental hard tissues are good candidates for age estimation as they are less destructive and procedures to determine age can be easily performed. Although cementum annulations and cementum thickness are important parameters in this regard, they are seldom used. This study was undertaken to review the methods, difficulties in execution of techniques, and accuracy of cementum thickness and annulations in estimating the age. Unstained and stained ground sections of tooth were used to measure cemental thickness and count cemental annulations based on which age was estimated and was compared with known age. Although there was positive relation between cemental thickness and annulations with age, only in 1–1.5% of cases, age could be predicted with accuracy.  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