全文获取类型
收费全文 | 15532篇 |
免费 | 482篇 |
专业分类
各国政治 | 826篇 |
工人农民 | 583篇 |
世界政治 | 1151篇 |
外交国际关系 | 584篇 |
法律 | 9546篇 |
中国共产党 | 2篇 |
中国政治 | 178篇 |
政治理论 | 3028篇 |
综合类 | 116篇 |
出版年
2020年 | 201篇 |
2019年 | 235篇 |
2018年 | 311篇 |
2017年 | 365篇 |
2016年 | 372篇 |
2015年 | 287篇 |
2014年 | 340篇 |
2013年 | 1698篇 |
2012年 | 380篇 |
2011年 | 485篇 |
2010年 | 362篇 |
2009年 | 380篇 |
2008年 | 414篇 |
2007年 | 419篇 |
2006年 | 423篇 |
2005年 | 359篇 |
2004年 | 381篇 |
2003年 | 424篇 |
2002年 | 323篇 |
2001年 | 628篇 |
2000年 | 578篇 |
1999年 | 480篇 |
1998年 | 225篇 |
1997年 | 167篇 |
1996年 | 183篇 |
1995年 | 162篇 |
1994年 | 181篇 |
1993年 | 162篇 |
1992年 | 280篇 |
1991年 | 295篇 |
1990年 | 269篇 |
1989年 | 282篇 |
1988年 | 281篇 |
1987年 | 291篇 |
1986年 | 281篇 |
1985年 | 289篇 |
1984年 | 253篇 |
1983年 | 277篇 |
1982年 | 181篇 |
1981年 | 156篇 |
1980年 | 142篇 |
1979年 | 190篇 |
1978年 | 148篇 |
1977年 | 129篇 |
1976年 | 121篇 |
1975年 | 103篇 |
1974年 | 105篇 |
1973年 | 105篇 |
1972年 | 91篇 |
1971年 | 100篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
A biomechanical study of the human vertebral artery with implications for fatal arterial injury 总被引:8,自引:0,他引:8
We studied the biomechanical behaviour of ring and strip specimens from along the length of 18 vertebral arteries taken from 16 subjects aged 28-90 years, in order to consider some of the factors which may play a role in vertebral artery rupture. The method was chosen to allow a comparison between circumferential distension (ring samples) and longitudinal extension, (strip samples). The samples were extended between the jaws of a tensile testing apparatus until the specimen broke and a number of biomechanical parameters were derived. These were the percentage extension to break, the tensile strength, Young's modulus and the peak load. There were a number of important findings. The vertebral artery was shown to be susceptible to longitudinal stretching with a number of strip samples breaking when extended by as little as 16-20%. The tensile strength and load at peak of the strip specimens were correspondingly lower than for the ring samples. Marked intersubject variations were shown for all these parameters and prominent changes in behaviour occurred along the vertebral artery. This study indicates that the artery may be susceptible to head and neck movements which cause the vessel to stretch, and intersubject variations in behaviour may be one important explanation for the marked differences in outcome which appear to exist in subjects who suffer broadly similar head and neck insults. 相似文献
962.
The paper extends on the traditional methodology used to quantify DNA evidence in paternity or identification cases. By extending we imply that there are more than two alternatives to choose between. In a standard paternity case the two competing explanations H(1): "John Doe is the father of the child and H(2): "A random man is the father of the child, are typically considered. A paternity index of 100000 implies that the data is 100000 more likely assuming hypothesis H(1) rather than H(2). If H(2) is replaced by "A brother of John Doe is the father", the LR may change dramatically. The main topic of this paper is to determine the most probable pedigree given a certain set of data including DNA profiles. In the previous example this corresponds to determining the most likely relation between John Doe and the child. Based on DNA obtained from victims of a fire, bodies found in an ancient grave or from individuals seeking to confirm their anticipated family relations, we would like to determine the most probable pedigree. The approach we present provides the possibility to combine non-DNA evidence, say age of individuals, and DNA profiles. The program familias, obtainable as shareware from http://www.nr.no/familias, delivers the probabilities for the various family constellations. More precisely, the information (if any) prior to DNA is combined with the DNA-profiles in a Bayesian manner to deliver the posterior probabilities. We exemplify using the well published Romanov data where the accepted solution emerges among 4536 possibilities considered. Various other applications based on forensic case work are discussed. In addition we have simulated data to resemble an incest case. Since the true family relation is known in this case, we may evaluate the method. 相似文献
963.
Boglioli LR Taff ML Turkel SJ Taylor JV Peterson CD 《The American journal of forensic medicine and pathology》2000,21(4):389-394
An unusual form of fatal child abuse is reported in which investigations by the police and the medical examiner were able to distinguish blunt force head trauma followed by postmortem dismemberment from a fatal dog attack. A discussion of the approaches used to ascertain the correct diagnosis is presented, as well as an overview of dog attacks on humans. 相似文献
964.
Jones LS Wyatt JP Busuttil A 《The American journal of forensic medicine and pathology》2000,21(4):401-405
Death resulting from plastic bag asphyxia has been recognized for >40 years, but relatively little is known about either its epidemiology or its pathophysiology. Over 15 years (1984-1998), 30 deaths were attributed to plastic bag asphyxia among the 14,560 autopsies performed in the Forensic Medicine Unit in Edinburgh. These 30 deaths involved 20 male and 10 female subjects, with an age range of 13 to 81 years. Eleven had some alcohol measurable in the blood, with four having levels >80 mg/dl. Only one individual appeared to have ingested a drug overdose, but inhaled substances within the plastic bag may have contributed to death in five cases. The absence of childhood accidental deaths may reflect successful preventive measures. The 3 accidental deaths involved adults (including 2 who died of autoerotic asphyxia), and the remaining deaths were 27 suicides. Of those who committed suicide, most (59%) had chronic psychiatric illness rather than chronic debilitating or terminal physical illness. In contrast with reports from the United States, publicity associated with "self-deliverance" did not result in an increased number of deaths from plastic bag asphyxia (4 deaths in this series). Analysis of the circumstances of all the deaths revealed them to be difficult to predict and hence prevent. 相似文献
965.
966.
967.
968.
Analysis of eight STR loci in two Hungarian populations 总被引:1,自引:0,他引:1
Egyed B Füredi S Angyal M Boutrand L Vandenberghe A Woller J Pádár Z 《Forensic science international》2000,113(1-3):25-27
A collection of eight STR loci (D3S1358, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) was used to generate allele frequency databases for two Hungarian population samples, Caucasians from the Budapest area and Romanies from Baranya county. During the analysis two intermediate sized alleles and a sequence variant allele were observed at the D7S820 locus. All three types of allelic variants were found to have modification (deletion, insertion, transversion) in the same block of a (T)(9) stretch located within the 3' flanking region of each allele, which may indicate a possible higher mutation rate of this (T)(9) block. For the loci D3S1358 and D7S820 the Romany population database showed departures from Hardy-Weinberg equilibrium. The forensic efficiency values for the Romany population were slightly different from those found in the Hungarian Caucasian population. Comparing the allele frequency values by G-statistic, calculating the F(st) indices and with the pairwise comparisons of inter-population variance, the two Hungarian populations could be distinguished using data of the eight STR loci. 相似文献
969.
Chattopadhyay PK Cleef S Duelmer M Henke L Henke J 《Forensic science international》2000,113(1-3):29-32
This study provides Jat Sikhs population data in North India for nine short tandem repeat (STR) loci. 相似文献
970.
Binda S Borer UV Gehrig C Hochmeister M Budowle B 《Forensic science international》2000,108(2):117-120
Allele and genotype frequencies for the ten STR loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01, FGA were determined in a Swiss Caucasian population sample (n=206) using the AmpFISTR SGM Plus Amplification kit. Electrophoresis was carried out on an ABI PRISM CE 310 Genetic Analyzer instrument. Previously, allele frequencies were published for the 13 STR loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, THO1, TPOX, CSF1PO and D16S539 for the same samples (n=206) amplified with the AmpFISTR Profiler Plus and Cofiler PCR Amplification kits. Since the results for the eight loci D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, THO1, D16S539 shared between the AmpFISTR SGM Plus, Profiler Plus and Cofiler PCR Amplification kits already are published, only the allele frequencies for the two STR loci D2S1338 and D19S433 are reported in this paper. The two loci meet Hardy-Weinberg expectations. In addition, there is little evidence for association of alleles among the 15 loci (amplified with the Profiler, Cofiler, and SGM Plus amplification kits). The allelic frequency data can be used in forensic analyses to estimate the frequency of a multiple STR locus DNA profile in the Swiss population. 相似文献