全文获取类型
收费全文 | 6903篇 |
免费 | 206篇 |
专业分类
各国政治 | 338篇 |
工人农民 | 241篇 |
世界政治 | 534篇 |
外交国际关系 | 238篇 |
法律 | 4091篇 |
中国政治 | 44篇 |
政治理论 | 1553篇 |
综合类 | 70篇 |
出版年
2020年 | 78篇 |
2019年 | 103篇 |
2018年 | 149篇 |
2017年 | 136篇 |
2016年 | 144篇 |
2015年 | 110篇 |
2014年 | 111篇 |
2013年 | 741篇 |
2012年 | 145篇 |
2011年 | 160篇 |
2010年 | 155篇 |
2009年 | 154篇 |
2008年 | 162篇 |
2007年 | 169篇 |
2006年 | 183篇 |
2005年 | 155篇 |
2004年 | 147篇 |
2003年 | 162篇 |
2002年 | 152篇 |
2001年 | 222篇 |
2000年 | 184篇 |
1999年 | 163篇 |
1998年 | 100篇 |
1997年 | 98篇 |
1996年 | 70篇 |
1995年 | 80篇 |
1994年 | 79篇 |
1993年 | 86篇 |
1992年 | 121篇 |
1991年 | 155篇 |
1990年 | 129篇 |
1989年 | 144篇 |
1988年 | 134篇 |
1987年 | 155篇 |
1986年 | 139篇 |
1985年 | 149篇 |
1984年 | 136篇 |
1983年 | 139篇 |
1982年 | 101篇 |
1981年 | 108篇 |
1980年 | 100篇 |
1979年 | 96篇 |
1978年 | 75篇 |
1977年 | 60篇 |
1976年 | 67篇 |
1975年 | 63篇 |
1974年 | 69篇 |
1973年 | 69篇 |
1972年 | 56篇 |
1969年 | 58篇 |
排序方式: 共有7109条查询结果,搜索用时 15 毫秒
991.
Byard RW Blumbergs P Scott G Kennedy JD Riches KJ Martin J Thompson GN 《The American journal of forensic medicine and pathology》2006,27(4):340-344
This report highlights the importance of undertaking immunohistochemical staining of the brains of infants who die unexpectedly, as it may not only assist with the evaluation of the cause of death in an individual infant but may also help with the clinical management of subsequent siblings. A 5-month-old male infant who died suddenly was found to have diffuse beta-amyloid precursor protein (beta-APP) staining in the brain, with no unusual features in his history, death scene examination, routine autopsy dissection, and ancillary tests to suggest any definite cause of death. Due to the beta-APP staining, the possibility of previous episodes of occult trauma, apparent life threatening events (ALTEs), and accidental or inflicted suffocation was raised in the autopsy report. As detailed analyses and investigations provided no supportive evidence for trauma or inflicted injury, hypoxia was clinically considered the most likely cause. Because of these concerns, sleeping oxygen saturation levels were monitored following the birth of a subsequent sibling who had normal APGAR scores and no evidence of any health problems. Oxygen desaturation to 70% occurred in association with a color change while on the postnatal ward, and a subsequent polysomnogram showed multiple episodic significant desaturations to around 80% in association with central apnea. Other testing was unremarkable. These cases demonstrate that beta-APP staining of the brain may not only provide clues as to possible mechanisms of death in pediatric forensic cases but may indicate a need for careful clinical evaluation of subsequent siblings for possible central apnea requiring oxygen therapy. 相似文献
992.
A method was developed for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), norbenzoylecgonine (BNE), norcocaine (NCOC), ecgonine (ECG), ecgonine methyl ester (EME), m-hydroxybenzoylecgonine (HBZE), anhydroecgonine methyl ester (AEME), cocaethylene (CE), norcocaethylene (NCE), and ecgonine ethyl ester (EEE) in blood, urine, and muscle. Available deuterated analogs of these analytes were used as internal standards. Proteins from blood and muscle homogenate were precipitated with cold acetonitrile. After the removal of acetonitrile by evaporation, the supernatants and urine were subjected to solid-phase extraction. The eluted analytes were converted to their hydrochloride salts and derivatized with pentafluoropropionic anhydride and 2,2,3,3,3-pentafluoro-1-propanol. The derivatized products were analyzed by a gas chromatograph (GC)/mass spectrometer by selected ion monitoring. The limit of detection (LOD) for COC, BZE, NCOC, EME, CE, NCE, and EEE was 2ng/ml, while the LODs for BNE, ECG, HBZE, and AEME were 25, 640, 50, and 13 ng/ml, respectively. This method was successfully applied in analyzing 13 case samples from aviation accident pilot fatalities and motor vehicle operators. AEME concentrations found in the 13 samples were consistent with those produced solely by the GC inlet pyrolysis of COC controls in blood. Anhydroecgonine cannot be used as a marker for the abuse of COC by smoking because it is also pyrolytically produced from COC metabolites on the GC inlet. The developed method can be effectively adopted for analyzing COC and related compounds in urine, blood, and muscle by a single extraction with increased sensitivity through formation of hydrochloride salts and using a one-step derivatization. 相似文献
993.
Mathewes RW 《Forensic science international》2006,163(3):198-203
Palynological analysis is shown from published and unpublished Canadian examples to be a useful tool in forensic investigation, although the technique is almost unknown and therefore under-utilized by forensic investigators. The techniques of pollen and spore identification and interpretation are continually improving, indicating that the potential for forensic applications is real. Focus in this paper is on an updated interpretation of palynological data that was presented during a trial involving a scientific test of oral history as part of a claim for aboriginal title to a large area of British Columbia (BC) (Delgamuukw versus the Queen). Although the original decision in British Columbia Supreme Court was decided in favor of the government defendants, an appeal to the Supreme Court of Canada overturned the original decision, and established new principles and rights for aboriginal peoples. 相似文献
994.
X-chromosomal markers are particularly useful for solving complex problems relating to kinship and deficiency paternity analysis. In the present study, population genetics data of four X-chromosomal short tandem repeats (STRs) DXS8378, HPRTB, DXS7423 and DXS7132 were obtained by analyzing 500 unrelated Chinese individuals (250 males and 250 females). Population genetics data obtained from the Chinese were compared with those of the Asian and European population. Mutations in X-chromosomal markers were analyzed based on a total of 61 proven father-child and 45 proven mother-child pairs. 相似文献
995.
Henry W. Morton 《欧亚研究》1980,32(2):235-259
996.
997.
998.
A W Jones 《Forensic science international》1985,28(3-4):147-156
A breath-alcohol screening device, Alcolmeter pocket model, was evaluated in a controlled field trial with policeman operating the instruments. The results of tests made with subjects before they drank alcohol were always zero. The standard deviation (S.D.) of breath alcohol determinations increased with increase in the concentration of alcohol in the sample, being 0.036 mg/ml at a mean blood-ethanol concentration of 0.53 mg/ml. The S.D. varied among subjects tested (from 0.022 to 0.053 mg/ml) as well as among the instruments used (from 0.023 to 0.054 mg/ml). The breath test results were on average less than the actual blood-ethanol concentrations when a 2100: 1 blood/breath ratio was used to calibrate the Alcolmeter device. Blood ethanol (x) and Alcolmeter readings (y) were highly correlated (r = 0.95 +/- 0.018) and the regression equation was y = -0.017 + 0.95x. At a mean blood-ethanol concentration of 0.50 mg/ml, the Alcolmeter instrument will indicate 0.46 mg/ml on average. The standard error estimate was 0.085 mg/ml, being 17% of the mean Alcolmeter reading and this corresponds to 95% confidence limits of +/- 0.17 mg/ml. The results of this study show that Alcolmeter pocket-model is a useful device for breath-alcohol screening purposes at a blood-alcohol level of 0.50 mg/ml. A blood/breath ratio of 2300 should be used to calibrate the Alcolmeter device. 相似文献
999.
1000.
Chris E. Marshall Ineke Haen Marshall Charles W. Thomas 《Journal of criminal justice》1983,11(3):195-211
Discriminant analysis of both observational and records data from two juvenile court systems is used to assess differences in the type and activities of the people involved in legal processing of status and nonstatus offenders. The analysis indicates that there are differences between the processing of the two categories of offenders; however, contrary to expectations, the most powerful discriminating variables (detention and petitioner) are not those related to the degree in which the justice system has implemented the formalities mandated by the Gault decision. It is concluded that statutory distinctions between legal categories of juveniles have virtually no relevance for the degree of formality with which these cases are processed by the courts. 相似文献