全文获取类型
收费全文 | 4471篇 |
免费 | 121篇 |
专业分类
各国政治 | 185篇 |
工人农民 | 154篇 |
世界政治 | 303篇 |
外交国际关系 | 173篇 |
法律 | 3204篇 |
中国政治 | 17篇 |
政治理论 | 519篇 |
综合类 | 37篇 |
出版年
2023年 | 26篇 |
2021年 | 40篇 |
2020年 | 72篇 |
2019年 | 81篇 |
2018年 | 125篇 |
2017年 | 106篇 |
2016年 | 120篇 |
2015年 | 65篇 |
2014年 | 108篇 |
2013年 | 416篇 |
2012年 | 134篇 |
2011年 | 172篇 |
2010年 | 100篇 |
2009年 | 82篇 |
2008年 | 139篇 |
2007年 | 152篇 |
2006年 | 138篇 |
2005年 | 110篇 |
2004年 | 152篇 |
2003年 | 143篇 |
2002年 | 130篇 |
2001年 | 171篇 |
2000年 | 162篇 |
1999年 | 111篇 |
1998年 | 25篇 |
1994年 | 26篇 |
1993年 | 35篇 |
1992年 | 68篇 |
1991年 | 90篇 |
1990年 | 90篇 |
1989年 | 95篇 |
1988年 | 101篇 |
1987年 | 94篇 |
1986年 | 77篇 |
1985年 | 79篇 |
1984年 | 69篇 |
1983年 | 59篇 |
1982年 | 28篇 |
1979年 | 35篇 |
1978年 | 37篇 |
1977年 | 24篇 |
1976年 | 27篇 |
1975年 | 29篇 |
1974年 | 37篇 |
1973年 | 45篇 |
1972年 | 37篇 |
1971年 | 43篇 |
1970年 | 39篇 |
1969年 | 32篇 |
1968年 | 27篇 |
排序方式: 共有4592条查询结果,搜索用时 0 毫秒
181.
182.
Solokhin AA Gaĭvoronskaia VI Kandaurov RV Persichkin AA 《Sudebno-meditsinskaia ekspertiza》2002,45(5):5-7
The article presents the results of an examination of the dry residue of liquor crystallograms (DRLC) using infrared spectroscopy technique. 36 spectrograms were studied. Elements of similarity and difference were revealed in the spectrograms of organic substance (antifreeze, sodium cyclamate and fatty tissue), of DRLC of the crystal-forming matter CuCl(2)x2H(2)0, of DRLC of a live person and cadaveric liquor (with no brain injury in respective case histories), of DRLC of liquor of live persons with a brain injury, of DRLC of liquor of persons who died of a brain injury and of persons who died of other causes. 相似文献
183.
Pavlov IuV 《Sudebno-meditsinskaia ekspertiza》2002,45(5):26-28
The paper describes specific morphological features of hairs from the head, beard, chest, axilla, pubis of the native population of Syria, India, Lebanon, Jordan, Yemen, Nepal, Palestine, Bahrain, Iraq and some residents of the Eastern Europe (Russians, Belorussians, Ukrainians). The hairs were studied macroscopically and microscopically (light microscopy). Digital data on hair thickness and number of lines of cuticula pattern were analysed using methods of variance statistics. Original information on some macro- and microscopic characteristics of hair has been obtained for citizens of the above countries. 相似文献
184.
185.
Bile is, in certain cases, collected together with blood from different sites (heart, brain, femoral), urine and other organs or matrices. This study reports comparative results obtained from the analysis of blood and bile for different drugs found: acetaminophen, amphetamine and related compounds, several antidepressants, several benzodiazepines, cocaine and its metabolites, dextropropoxyphene and its metabolite, hydroxyzine, methadone and metabolite, morphine and codeine, levomepromazine, thioridazine, propranolol, tramadol and its metabolite. Several findings are presented: (1) There were no significant differences in the levels of the compounds among the samples of blood obtained from different sites. (2) Levels in bile are generally several fold higher than those in blood. The mean bile to blood ratios vary from about 1 (for acetaminophen, amphetamine) to about 2000 (for desmethylclobazam). (3) In certain cases (16 over 44), although the drug or its metabolite was not detected in blood from different sites, it was detected in bile. As other authors had advocated, it is very useful to ask the pathologist to take the gall bladder with its contents together with the other samples, in order that the sample of bile can be used in the comprehensive toxicological analysis and therefore be complementary to the other fluids or matrices. An additional advantage for using bile is that the concentrations of drugs or their metabolites are generally several fold higher than their blood concentrations. 相似文献
186.
Baptista MJ Monsanto PV Pinho Marques EG Bermejo A Avila S Castanheira AM Margalho C Barroso M Vieira DN 《Forensic science international》2002,128(1-2):66-78
A sensitive analytical method was developed for quantitative analysis of delta(9)-tetrahydrocannabinol (delta(9)-THC), 11-nor-delta(9)-tetrahydrocannabinol-carboxylic acid (delta(9)-THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in human hair. The identification of delta(9)-THC-COOH in hair would document Cannabis use more effectively than the detection of parent drug (delta(9)-THC) which might have come from environmental exposure. Ketamine was added to hair samples as internal standard for CBN and CBD. Ketoprofen was added to hair samples as internal standard for the other compounds. Samples were hydrolyzed with beta-glucuronidase/arylsulfatase for 2h at 40 degrees C. After cooling, samples were extracted with a liquid-liquid extraction procedure (with chloroform/isopropyl alcohol, after alkalinization, and n-hexane/ethyl acetate, after acidification), which was developed in our laboratory. The extracts were analysed before and after derivatization with pentafluoropropionic anhydride (PFPA) and pentafluoropropanol (PFPOH) using a Hewlett Packard gas chromatographer/mass spectrometer detector, in electron impact mode (GC/MS-EI). Derivatized delta(9)-THC-COOH was also analysed using a Hewlett Packard gas chromatographer/mass spectrometer detector, in negative ion chemical ionization mode (GC/MS-NCI) using methane as the reagent gas. Responses were linear ranging from 0.10 to 5.00 ng/mg hair for delta(9)-THC and CBN, 0.10-10.00 ng/mg hair for CBD, 0.01-5.00 ng/mg for delta(9)-THC-COOH (r(2)>0.99). The intra-assay precisions ranged from <0.01 to 12.40%. Extraction recoveries ranged from 80.9 to 104.0% for delta(9)-THC, 85.9-100.0% for delta(9)-THC-COOH, 76.7-95.8% for CBN and 71.0-94.0% for CBD. The analytical method was applied to 87 human hair samples, obtained from individuals who testified in court of having committed drug related crimes. Quantification of delta(9)-THC-COOH using GC/MS-NCI was found to be more convenient than GC/MS-EI. The latter may give rise to false negatives due to the detection limit. 相似文献
187.
Sánchez-Diz P Lareu MV Brión M Skitsa I Carracedo A 《Forensic science international》2002,126(3):265-266
Allele frequencies for the nine STRs included in the AmpFlSTR Profiler Plus kit (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) were estimated from a sample of 143 unrelated individuals living in different regions of Greece. 相似文献
188.
Polymorphism at 15 microsatellite loci was studied in four predominant, endogamous populations of Maharashtra state in India. The studied population included Marathas, Desasth Brahmins, Chitpavan Brahmins and Dhangars; all of whom belong to Marathi speaking linguistic group of India. The distribution of the allele pattern at 13 tetranucleotide repeat and two pentanucleotide repeat of Powerplex 16 System portrays that these markers are highly polymorphic and thus, informative in human identification and understanding diversity in the addressed populations. 相似文献
189.
Although microsatellite diversity in autosomal chromosomes has been extensively described for many of the Indian populations, there is still a lacuna left on information about the genetic diversity of tribal populations. This paper reports the genetic data on the three tribal populations belonging to the Austroloid ethnic group from Orissa (Juang, Paroja and Saora). The 15 STR (D3S1358, THO1, D21S11, D18S51, PentaE, D5S818, D13S317, D7S820, D16S539, CSF1PO, PentaD, vWA, D8S1179, TPOX, FGA) polymorphism would help to accentuate the STR database for better understanding of population genetics and forensic applications. The microsatellites included in the system are found to be highly polymorphic, with the combined power of exclusion being greater than 0.999, in all the three investigated populations. 相似文献
190.
This study examined the factors associated with resistance to peer pressure toward antisocial behaviors among a sample of Mexican-origin adolescents (n=564) living in a large Southwestern city in the U.S. A model examining the influence of generational status, emotional autonomy from parents, and self-esteem on resistance to peer pressure was tested independently for boys and girls. Gender differences emerged in the factors that influenced resistance to peer pressure. Results indicated that resistance to peer pressure was influenced by generational status and emotional autonomy from parents for both boys and girls. However, self-esteem was found to influence resistance to peer pressure only for boys.Mayra Y. Bámaca is a graduate student in Family and Human Development at Arizona State University. Her research interests include adolescent development among ethnically diverse populations, the influence of contextual factors in development, parenting adolescents, and resiliency among Latino adolescents and their families. This work was based on the master’s thesis of the first author.Adriana J. Uma?a-Taylor received her Ph.D. from the University of Missouri-Columbia and is currently an Assistant Professor of Family and Human Development at Arizona State University. Her research interests include ethnic identity formation during adolescence and resilience among Latino adolescents and their families.This study was supported, in part, by a grant to the second author from the Fahs Beck Fund for Research and Experimentation of the New York Community Trust. 相似文献