首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15742篇
  免费   197篇
各国政治   665篇
工人农民   1350篇
世界政治   675篇
外交国际关系   595篇
法律   9236篇
中国政治   50篇
政治理论   3313篇
综合类   55篇
  2020年   90篇
  2019年   114篇
  2018年   1388篇
  2017年   1356篇
  2016年   1169篇
  2015年   178篇
  2014年   171篇
  2013年   870篇
  2012年   353篇
  2011年   1070篇
  2010年   1153篇
  2009年   730篇
  2008年   917篇
  2007年   893篇
  2006年   216篇
  2005年   232篇
  2004年   333篇
  2003年   315篇
  2002年   165篇
  2001年   283篇
  2000年   242篇
  1999年   227篇
  1998年   110篇
  1997年   88篇
  1996年   90篇
  1995年   92篇
  1994年   98篇
  1993年   69篇
  1992年   123篇
  1991年   166篇
  1990年   160篇
  1989年   144篇
  1988年   150篇
  1987年   165篇
  1986年   161篇
  1985年   149篇
  1984年   140篇
  1983年   131篇
  1982年   87篇
  1981年   92篇
  1980年   69篇
  1979年   132篇
  1978年   95篇
  1977年   81篇
  1976年   57篇
  1975年   82篇
  1974年   88篇
  1973年   84篇
  1972年   56篇
  1971年   57篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Hjelmeland H  Grøholt B 《危机》2005,26(2):64-72
Research has shown that the prevalence of deliberate self-harm (DSH) is higher in adolescents than in adults, but little is known about other differences. In this study we compare adolescent and adult DSH-patients regarding factors contributing to the suicidal act. In two regions in Norway, 98 persons under 20 years of age and 83 older persons were interviewed following an act of DSH. They were compared regarding intentions involved in the DSH, precipitating circumstances, level of suicidal intent, medical seriousness of the act, depression, hopelessness, and self-esteem. Few differences were found. The adults more often wanted to escape from unbearable thoughts or situations, or to receive care and attention. Adults also reported a slightly higher level of medical seriousness of the DSH act, more psychiatric problems, and substance abuse. The similarities between young and adult DSH-patients are striking. The differences found are most likely related to factors of age itself, such as cognitive immaturity, impulsivity, and lack of experience in enduring problems.  相似文献   
993.
In a second test of an arthropod saturation hypothesis, we analyzed if the on-campus Anthropology Research Facility (ARF) at the University of Tennessee, Knoxville, with its 20+ yr history of carcass enrichment, is comparable to non-enriched sites in community structure of predatory and parasitic arthropods that prey upon the sarcosaprophagous fauna. Over a 12-day period in June 1998, using pitfall traps and sweep nets, 10,065 predaceous, parasitic, and hematophagous (blood-feeding) arthropods were collected from freshly euthanized pigs (Sus scrofa L.) placed at ARF and at three surrounding sites various distances away (S2-S4). The community structure of these organisms was comparable in most paired-site tests with respect to species composition, colonization rates, and evenness of pitfall-trap abundances on a per carcass basis. Site differences were found in rarefaction tests of both sweep-net and pitfall-trap taxa and in tests of taxonomic evenness and ranked abundances of sweep-net samples. Despite these differences, no evidence was found that the predatory/parasitic fauna at ARF was impoverished with fewer but larger populations as a result of carcass enrichment. Comparison of the sarcosaprophagous and predatory/parasitic faunas revealed a tighter (and more predictable) linkage between carrion feeders (sarcosaprovores) and their carrion than between carrion feeders and their natural enemies (predators and parasitoids), leading us to conclude that ARF is more representative of surrounding sites with respect to the sarcosaprovore component than to the predatory/parasitic component within the larger carrion-arthropod community.  相似文献   
994.
A few papers in the literature reported incident deaths by acute ketamine poisoning. In this paper, we report an unusual homicide caused by chronic ketamine poisoning. The victim was a 34-year old married woman with no previous medical history (except as reported herein) who died in her own home. The court investigation revealed that she was chronically poisoned by her husband over a period of about one year in an act of homicide. Determination of ketamine concentrations in autopsy specimens was carried out with gas-chromatography/mass spectrometry (GC-MS). The results showed that ketamine concentration was 21 microg/mL in gastric contents, 3.8 microg/mL in blood and 1.2 microg/mL in urine. The most striking forensic findings were cardiac muscle fibrosis and hyaline degeneration of small arteries in victim's heart, the pathological features of ketamine poisoning previous reported only in animal studies.  相似文献   
995.
996.
997.
998.
The effects of an intramural cognitive-behavioral treatment for forensic inpatients with personality disorders in a high-security hospital were examined. Treatment was aimed at modifying maladaptive coping and social skills, at enhancing social awareness, at reducing egoistic and oppositional behaviors, and at reducing psychological complaints. The patients, who all had committed serious crimes (violence, arson, sexual offences), participated voluntarily in the study. A total of 39 patients started the study, but during the course of the study, several patients dropped out because of several reasons. Patients as a group showed significant improvements over time on psychopathological symptoms, personality traits, and coping. A significant decrease of oppositional behaviors was reported by the staff. Though the patients improved well at the group level, only a minority of patients showed reliable change over time at the individual level. The meaning of the results in relation to treatment are discussed.  相似文献   
999.
This study was designed to compare the qualitative results and concentrations of methamphetamine (MA) and its metabolite amphetamine (AP) in head hair and hair collected from different parts of the body (axillae and pubis). Hair from subjects (N = 14) suspected MA users was simultaneously collected. Hair preparation involved washing step, fine cutting, overnight extraction, derivatization by the trifluoroacetic anhydride, and gas chromatography/mass spectrometry (GC/MS) using selective ion monitoring. In this study, we found a good correlation of the qualitative results for MA between head hair and hair on other parts of the body, but there were some differences in concentrations of MA and AP. Namely, the concentrations of MA and AP were higher in axillary and pubic hair than in head hair.  相似文献   
1000.
The population genetic data of 18 X-chromosomal short tandem repeat (STR) markers DXS6807, DXS8378, DXS9895, DXS9902, DXS6810, DXS7132, DXS981, DXS6800, DXS9898, DXS6789, DXS101, DXS6797, GATA172D05, GATA165B12, HPRTB, GATA31E08, DXS8377, and DXS7423 were analyzed in samples of unrelated 220 males and 181 females from Korean population. The exact test for genotype distribution of the markers showed no significant deviation from the Hardy-Weinberg equilibrium. Allele frequencies between male and female samples were not significantly different in all examined markers. All examined males and females showed different hemizygotic haplotype and combined genotypes, respectively. Four cases of mutation were found in GATA172D05, GATA31E08, DXS7132, and HPRTB from the analysis of 95 father-child-mother trios. Details of X chromosomal STRs in Koreans would be useful in paternity tests and forensic purposes as well as whole X-chromosomal mapping studies.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号