全文获取类型
收费全文 | 12951篇 |
免费 | 314篇 |
专业分类
各国政治 | 735篇 |
工人农民 | 516篇 |
世界政治 | 954篇 |
外交国际关系 | 480篇 |
法律 | 7822篇 |
中国政治 | 100篇 |
政治理论 | 2593篇 |
综合类 | 65篇 |
出版年
2020年 | 136篇 |
2019年 | 190篇 |
2018年 | 247篇 |
2017年 | 257篇 |
2016年 | 258篇 |
2015年 | 173篇 |
2014年 | 263篇 |
2013年 | 1354篇 |
2012年 | 305篇 |
2011年 | 320篇 |
2010年 | 291篇 |
2009年 | 310篇 |
2008年 | 357篇 |
2007年 | 350篇 |
2006年 | 338篇 |
2005年 | 295篇 |
2004年 | 303篇 |
2003年 | 287篇 |
2002年 | 226篇 |
2001年 | 547篇 |
2000年 | 475篇 |
1999年 | 399篇 |
1998年 | 179篇 |
1997年 | 162篇 |
1996年 | 132篇 |
1995年 | 132篇 |
1994年 | 133篇 |
1993年 | 115篇 |
1992年 | 240篇 |
1991年 | 289篇 |
1990年 | 272篇 |
1989年 | 262篇 |
1988年 | 253篇 |
1987年 | 293篇 |
1986年 | 256篇 |
1985年 | 236篇 |
1984年 | 230篇 |
1983年 | 206篇 |
1982年 | 144篇 |
1981年 | 161篇 |
1980年 | 112篇 |
1979年 | 205篇 |
1978年 | 135篇 |
1977年 | 104篇 |
1976年 | 87篇 |
1975年 | 122篇 |
1974年 | 129篇 |
1973年 | 136篇 |
1972年 | 98篇 |
1971年 | 95篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Fetal death has been defined by the World Health Organization as death before complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy. Certain causes of fetal death, including syphilis, Rh isoimmunization, toxemia, and diabetes, have shown significant declines over the past several decades. However, many fetal losses continue to occur from intrauterine infections, lethal malformations, fetal growth retardation, and abruptio placentae. Fetal death with no identifiable specific cause is another consideration when dealing with these cases. Other risk factors can include maternal, sociodemographic, and medical care factors. The authors reviewed all forensic cases referred for autopsy to the Forensic Section of the Medical University of South Carolina, Medical Examiners' Office over the 10-year period 1990-1999. All cases listed as fetal death or stillbirth were included. The 42 cases were analyzed as to fetus' gestational age, sex, race, weight, location of delivery, history of prenatal care, maternal drug use, chromosomal abnormalities, cause and manner of death, and autopsy findings. The black:white ratio was approximately 2:1, and the male:female ratio was virtually 1:1. Most fetuses were older than 20 weeks' gestational age, with one third between 20 and 29 weeks. The majority were externally normal aside from maceration. Only 7.5% had congenital anomalies. Twenty-one of 38 placentas were grossly and microscopically normal. Of cases with toxicologic analysis, 21% were positive for drugs, and 17% were positive for cocaine/benzoylecgonine. The manner of death was classified as natural (28), accident (2), and undetermined (12). Few studies have reported the specific causes of fetal death, and the lack of uniformity in data collection and classification of causes of fetal death has made comparisons difficult. The authors present this retrospective study to better determine the factors leading to fetal demise in the hope of assisting death investigators in this challenging arena. 相似文献
982.
Personal identification using Y-chromosomal short tandem repeats from bodily fluids mixed with semen 总被引:2,自引:0,他引:2
Tsuji A Ishiko A Ikeda N Yamaguchi H 《The American journal of forensic medicine and pathology》2001,22(3):288-291
The male-specific, human Y-chromosomal short tandem repeats (Y-STRs) are very useful in forensic analysis. The authors report a sexual crime case in which the direct Y-STR haplotype analysis of several mixtures of various bodily fluids including semen was very effective for identifying the perpetrator of the crime. The typing of three Y-STRs (DYS19, DYS389II, and DYS390) could be detected from the mixed DNA of sperm and female cells in the victim's vagina, vaginal orifice, and anus. These haplotypes originated from one man and matched those of the suspect. Accordingly, the combination of direct extraction of DNA and Y-STR haplotype analysis is considered to be very useful for mixtures of bodily fluids, including semen or other male cells. 相似文献
983.
Posttraumatic thrombosis of the middle cerebral artery 总被引:6,自引:0,他引:6
Bunai Y Nagai A Nakamura I Akaza K Ohya I 《The American journal of forensic medicine and pathology》2001,22(3):299-302
Posttraumatic cerebral infarction resulting from carotid or cerebral artery occlusion is rare. Traumatic dissection of the carotid artery is the most frequent cause of infarction, whereas posttraumatic thrombosis of the cerebral artery is very rare. The authors describe a case of posttraumatic thrombosis of the left middle cerebral artery. Early in the morning, a 16-year-old boy was found unconscious in the parking lot of a supermarket. He had received fist blows and kicks to the head, face, body, back, and hip during the night. Computed tomography 10 hours after the violence revealed a gross cerebral infarction in the area of the left middle cerebral artery. He died 9 days after the violence. The autopsy revealed a thrombosis in the left middle cerebral artery. Microscopically, granulation tissue in the intima and a rupture of the internal elastic lamina were observed near the beginning of the artery. It was concluded that the blows to the head and face caused a partial rupture in the arterial wall, leading to thrombosis and cerebral infarction. 相似文献
984.
985.
Gotoh M Sakata M Endo T Hayashi H Seno H Suzuki O 《Forensic science international》2001,116(2-3):221-226
Profenofos and its metabolites were determined in a case of fatal poisoning. Little profenofos and large amounts of metabolites were detected by gas chromatography/flame photometric detection in the acid extracts of blood and urine after methylation with diazomethane. Four major metabolites containing phosphorus were identified with the synthesized metabolites, namely, despropylated profenofos, desethylated profenofos and des-S-propylated profenofos, respectively. 4-Bromo-2-chlorophenol (BCP), an aryl moiety of profenofos, was also determined in blood and urine with high performance liquid chromatograph (HPLC) as free or conjugated metabolites. 相似文献
986.
Jedrzejowska ZK 《Forensic science international》2001,117(1-2):145-151
The aim of this work is to prove the application of craniometry in determining the identity of unknown bodies. There is a great correlation between the viscero-cranium appearance and the osseous structure, the said correlation following mathematical rules and thus being possible to be calculated. Various segments of the skull and different size of the angles they make with each other are directly responsible for the graphic profile of viscero-cranium. The nasal bones and their angle are the basis to determine the shape and size of the nose. 相似文献
987.
To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia. 相似文献
988.
Bohnert M Faller-Marquardt M Lutz S Amberg R Weisser HJ Pollak S 《Forensic science international》2001,116(2-3):107-115
In hanging and ligature strangulation, the noose mostly causes a mark or groove which is formed partly by compression of the skin and partly by abrasion with loss of the upper epidermal layers. The horny scales abraded from the neck may be transferred to the strangulation device or to the interposed textiles where they are sometimes visible at stereomicroscopic examination or even to the naked eye as silver-grey particles. The morphologic features of the epidermal transfer due to hanging and ligature strangulation is demonstrated by 14 case examples. The biological traces may be sufficient for comparative DNA typing by means of PCR-based methods. In 9 out of the 14 cases, genomic DNA typing was successful. Analysis of mtDNA succeeded in another two cases, although genomic DNA could not be detected. Beside the accumulation of solid epidermic particles the paper describes deposition of serous and fatty tissue fluid at the ligature (mainly adjacent to skin ridges). 相似文献
989.
990.
Kronebusch K 《Journal of health politics, policy and law》2001,26(6):1223-1260
From 1984 to 1990. Congress enacted a series of mandates that expanded Medicaid eligibility for low-income children by gradually delinking Medicaid eligibility from welfare eligibility. The 1996 national welfare reform law nominally completed the delinking process when the statutory phase-in of children's Medicaid coverage was preserved even as the states were given increased flexibility for administering welfare programs. This article provides estimates of the impact of these fedcral policy changes on children's Medicaid enrollment rates and analyzes the degree of success in uncoupling children's Medicaid enrollment from welfare. Data from the Current Population Survey for 1979 to 1998 are used to provide standardized enrollment probabilities for the United States and individual states. The results show important enrollment increases associated with the period of the mandated expansions, followed by enrollment declines associated with welfare reform. The largest increases in enrollment during this period were in states with historically restrictive welfare eligibility, but rates also rose in states that previously had relatively expansive welfare eligibility. The net effect was a reduction in the extent of state-to-state variation in enrollment. The Medicaid expansion peaked in 1995, prior to the advent of national welfare reform. Since then, children's Medicaid enrollment has fallen, with the largest declines falling on families with the very lowest incomes. Consistent with the desire to delink children's Medicaid coverage from welfare, the association between Medicaid and AFDC/TANF enrollment weakened during the expansionary period, but there still was a relatively strong relationship between policy outcomes for these two programs. Despite the policy changes, Medicaid coverage of children is still influenced by state-level welfare policy. 相似文献