全文获取类型
收费全文 | 1779篇 |
免费 | 111篇 |
专业分类
各国政治 | 103篇 |
工人农民 | 87篇 |
世界政治 | 158篇 |
外交国际关系 | 158篇 |
法律 | 900篇 |
中国政治 | 21篇 |
政治理论 | 449篇 |
综合类 | 14篇 |
出版年
2023年 | 26篇 |
2022年 | 21篇 |
2021年 | 29篇 |
2020年 | 60篇 |
2019年 | 77篇 |
2018年 | 83篇 |
2017年 | 100篇 |
2016年 | 98篇 |
2015年 | 63篇 |
2014年 | 83篇 |
2013年 | 262篇 |
2012年 | 82篇 |
2011年 | 59篇 |
2010年 | 51篇 |
2009年 | 51篇 |
2008年 | 64篇 |
2007年 | 86篇 |
2006年 | 59篇 |
2005年 | 67篇 |
2004年 | 54篇 |
2003年 | 43篇 |
2002年 | 55篇 |
2001年 | 24篇 |
2000年 | 26篇 |
1999年 | 26篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 19篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 22篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 13篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1971年 | 4篇 |
1969年 | 3篇 |
1966年 | 4篇 |
排序方式: 共有1890条查询结果,搜索用时 15 毫秒
101.
Bermejo Barrera P Lorenzo Alonso MJ Bermejo Barrera A Cocho de Juan JA Fraga Bermúdez JM 《Forensic science international》2000,107(1-3):149-156
A method for the selenium determination in a mother and her child's hair using palladium as a chemical modifier was optimized. The sample was digested with nitric acid and hydrogen peroxide and diluted to 5 ml. To achieve complete mineralization the samples were ashed at 1200 degrees C in the presence of palladium as a chemical modifier. The optimum atomization temperature was 1900 degrees C. The precision and accuracy of the method were studied using the reference material CRM 397. Results of calibration using aqueous standards and the standard addition method were compared. The method was applied to the selenium determination in 30 samples of the mother's and child's hair. The levels found were 0.54 +/- 0.34 microgram/g for mother's hair and 0.77 +/- 0.25 microgram/g for child's hair. 相似文献
102.
ABSTRACT This article traces the evolving political platform of one of Iraq’s oldest and most powerful Shi’i political parties, the Islamic Supreme Council of Iraq (ISCI). Drawing on an analysis of 15 years of primary materials produced by ISCI, it focuses principally on their promotion of decentralization as a path towards peace and stability in Iraq. However, the article also traces the origins of a deep schism that emerged within ISCI between the movement’s old guard who were beholden to the Iranian regime and their model of vilāyat-i faqīh, and the youth-led Iraqi nationalist faction who wanted to see the instalment of a civil government without religious oversight. The article demonstrates that this division is indicative of a theological debate between Shi’i religious scholars over differing interpretations of the role of Shi’ism in politics. The article concludes by arguing that understanding the extent to which such esoteric religious debates manifest themselves politically is crucial to interpreting divisions within Shi’ism not just in Iraq, but across the broader Middle East. 相似文献
103.
104.
In this study we propose several mathematical models for describing the behavior of crime-related systems. In the first part is presented a simple model for describing and measuring crime systems with recidivism. This model may be used in estimating the quantitative effects of alternative policies on crime rates. An important factor not recognized by the model is deterrence. One derivative of the mathematical analyses is a proposed method for measuring the relative severity of sentencing in a given system. The second part of the paper deals with the criminal population as a whole, trying to bring into account the non-stationary behavior of the system. This study should be regarded as a preliminary attempt to develop elementary mathematical models fitting crime systems. Some of the assumptions do not have substantial direct support by data. 相似文献
105.
Inge?VanderValkEmail author Ed?Spruijt Martijn?de?Goede Cora?Maas Wim?Meeus 《Journal of youth and adolescence》2005,34(6):533-546
In the present longitudinal 3-wave study of 1274 adolescents and young adults, aged 12–24 at the 1st wave, it is examined
whether youngsters from intact versus postdivorce families show long-term differences in internalizing and externalizing problems.
Furthermore, possible differences in the development of this problem behavior between offspring from intact and postdivorce
families are examined, i.e., possible differences in growth curves of internalizing and externalizing problems are investigated.
Longitudinal multilevel analyses reveal long-term differences in internalizing and externalizing problems according to family
structure. Adolescents and young adults growing up in postdivorce families display more internalizing and externalizing problem
behavior than youngsters of intact families. The development of these 2 types of problem behavior does not differ by gender
or family structure. That is, the shape of the growth curves of internalizing and externalizing problem behavior is similar
for boys and girls and also for youngsters from intact and postdivorce families.
Inge VanderValk is a Postdoc Researcher at the Department of Child and Adolescent Studies, Utrecht University, the Netherlands.
She received her Ph.D. in 2004 from Utrecht University. Her major research interests include associations between adolescent
adjustment and parental marital quality and parental divorce.
Ed Spruijt is an Associate Professor at the University of Utrecht. He received his Ph.D. in 1983 from Utrecht University.
His major research interests are the consequences of parental divorce and visitation arrangements on children.
Martijn de Goede is an associate Professor at Utrecht University, Department of Methodology and Statistics. He received his
Ph.D. in 1988 from Utrecht University. His major research interests are occupational and relational life courses of youngsters.
Cora Maas is an Assistent Professor at Utrecht University, Department of Methodology and Statistics. She received her PH.D.
in 1992 in Utrecht from Utrecht University. Her major interests are: multilevel analysis (theory and applications).
Wim Meeus is full Professor of Adolescent Development at Utrecht University. He received his Ph.D. in 1984 from Utrecht University.
His major research interests are personality, identity, and relationships in adolescence. 相似文献
106.
Sípoli Marques MA Pinto Damasceno LM Gualberto Pereira HM Caldeira CM Pereira Dias BF de Giacomo Vargens D Amoedo ND Volkweis RO Volkweis Viana RO Rumjanek FD Aquino Neto FR 《Journal of forensic sciences》2005,50(3):587-592
A clear positive case for anabolic steroids doping was confounded by alleged urine tampering during doping control procedures. Review of the chain of custody showed no flaws, but nevertheless the athlete was adamant that the urine sample should be analyzed for DNA in order to support her contention that she was not the donor of the sample. The results obtained showed that the urine sample that scored positive for steroids contained nuclear DNA that could not be matched to the DNA obtained from the athlete's blood. On the other hand, the same urine sample contained mitochondrial DNA whose nucleotide sequences spanning the hyper variable regions HV1 and HV2 proved to be identical to those determined in mitochondrial DNA amplified from the athlete's blood. The occurrence of an extraneous genotype is compatible with exogenous nuclear DNA admixture to the athlete's urine. Alternatively, taking in consideration the mitochondrial DNA, we could not exclude that a sibling or a maternal relative of the athlete could have acted as a donor of the urine utilized for doping control and DNA analysis. Both situations point to possible tampering of the urine by the athlete. Adjudication at CAS maintained previous national and international federation decision that there was no proof of a chain of custody flaw to justify the athlete's allegation of urine substitution after collection. 相似文献
107.
108.
109.
Salas A Prieto L Montesino M Albarrán C Arroyo E Paredes-Herrera MR Di Lonardo AM Doutremepuich C Fernández-Fernández I de la Vega AG Alves C López CM López-Soto M Lorente JA Picornell A Espinheira RM Hernández A Palacio AM Espinoza M Yunis JJ Pérez-Lezaun A Pestano JJ Carril JC Corach D Vide MC Alvarez-Iglesias V Pinheiro MF Whittle MR Brehm A Gómez J 《Forensic science international》2005,150(2-3):191-198
A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu. 相似文献
110.