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   1580篇
  免费   119篇
各国政治   159篇
工人农民   101篇
世界政治   190篇
外交国际关系   74篇
法律   864篇
中国政治   7篇
政治理论   299篇
综合类   5篇
  2023年   28篇
  2022年   6篇
  2021年   37篇
  2020年   50篇
  2019年   67篇
  2018年   84篇
  2017年   115篇
  2016年   83篇
  2015年   74篇
  2014年   84篇
  2013年   287篇
  2012年   89篇
  2011年   70篇
  2010年   37篇
  2009年   24篇
  2008年   66篇
  2007年   65篇
  2006年   55篇
  2005年   53篇
  2004年   59篇
  2003年   62篇
  2002年   45篇
  2001年   30篇
  2000年   30篇
  1999年   13篇
  1998年   10篇
  1997年   8篇
  1996年   6篇
  1995年   9篇
  1994年   3篇
  1993年   5篇
  1992年   5篇
  1991年   5篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1984年   2篇
  1983年   4篇
  1981年   2篇
  1978年   3篇
  1976年   1篇
  1975年   2篇
  1973年   2篇
  1972年   2篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
排序方式: 共有1699条查询结果,搜索用时 31 毫秒
911.
Intimate partner violence (IPV) constitutes a major public health problem in the United States. This cross-sectional survey of 108 emergency department (ED) care providers and 146 ED visitors at three metropolitan EDs compared the beliefs of ED health care providers with those of community members about the relative benefits of the helpfulness of resources for IPV victims using hypothetical case scenarios. Although providers generally indicated that help resources were helpful in all scenarios, visitors were more discriminating, showing less support for resources in the lower-risk scenario. Regarding differences between groups, visitors selected police and attorneys more frequently than providers as a helpful resource, whereas providers selected shelters and counselors more frequently than visitors. Adjustment for previous experience with IPV did not change these results. Understanding the differences between health care providers' and community members' perceptions of resources for victims of IPV may improve the effectiveness of referral to IPV resources.  相似文献   
912.
In forensic DNA analysis, the samples recovered from the crime scene are often highly degraded leading to poor PCR amplification of the larger sized STR loci. To avoid this problem, we have developed STR markers with redesigned primer sequences called "Miniplexes" to produce smaller amplicons. To assess the effectiveness of these kits, we have tested these primer sets with enzymatically degraded DNA and compared the amplifications to a commercial kit. We also conducted sensitivity and peak balance studies of three Miniplex sets. Lastly, we report a case study on two human skeletal remain samples collected from different environmental conditions. In both types of degraded DNA, the Miniplex primer sets were capable of producing more complete profiles when compared to the larger sized amplicons from the commercial kit. Correct genotypes were obtained at template concentrations as low as 31 pg/25 microL. Overall, our data confirm that our redesigned primers can increase the probability of obtaining a usable profile in situations where standard kits fail.  相似文献   
913.
An experiment was conducted in which the effectiveness of three line-up methods (live, video, and photographs) was compared. Participants witnessed a staged event and were subsequently required, by one of the three methods, to identify the target. Both target-present and target-absent line-ups were used. The results showed that all methods led to an equal number of correct identifications (hits). In the target-absent line-ups, participants more often incorrectly identified a person in the video and photographs condition than in the live condition. Presenting photographs simultaneously or sequentially did not affect the number of correct judgments. Dynamic video images, showing locomotion and facial expression, had a marginal significant effect on the number of correct judgments as compared with the static video images. Practical implications are discussed.  相似文献   
914.
This paper describes a procedure for the detection and quantification of ethyl-glucuronide (EtG) in hair samples. During method development the efficacy of extraction of EtG from hair was compared in four extraction methods: (a) methanol; (b) methanol:water (1:1); (c) water; and (d) water:trifluoroacetic acid (9:1). In addition, three derivatizing agents were compared as well: N,O-bistrimethylsilyl-trifluoroacetamide (BSTFA): trimethylchlorosilane (TMCS) (99:1), pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA). Water was found to be the best extracting solvent and PFPA the best derivatizing agent. Both provided the highest recoveries, with cleaner extracts and more stable derivatives. The final method is as follows: about 100mg of hair are sequentially washed with water and acetone. The decontaminated sample is finely cut with scissors, then the deuterated internal standard (EtG-d5) and 2 mL of water are added. After sonication for 2 h, the sample is maintained at room temperature overnight. Derivatization is performed with PFPA. Derivatives are injected into a GC-MS system in the electronic impact mode. The method shows linearity over the range of concentrations from 0.050 to 5 ng/mg. Detection and quantification limits are 0.025 and 0.050 ng/mg, respectively. Mean recoveries for the three studied concentrations (low, medium and high) are higher than 87%. The coefficients of variation in intra- and inter-assay precision are always lower than 7%. The method is being routinely applied in our lab for the diagnosis of chronic alcohol consumption.  相似文献   
915.
The introduction of anti-stalking statutes throughout Australia and much of the Western world has brought greater protection for the victims of various forms of harassment and intrusions. However, despite these new provisions, the legal system is failing some victims of stalking. This article examines those areas of the justice system that are particularly susceptible to manipulation by stalkers and the impact of these abuses on stalking victims. It also presents ways in which the problems encountered by stalking victims may be frustrated rather than alleviated by specific aspects of the enforcement of anti-stalking laws and of the functioning of certain courts and tribunals. Approaches that prevent or discourage the perpetuation of harassment and damage to victims of stalking within the legal system are discussed.  相似文献   
916.
917.
Haplotype, allele frequencies and population data of 17 Y-chromosome STR loci DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460 (GATA A7.1), DYS461 (GATA A7.2), GATA A10, GATA C4 and GATA H4 were determined from a sample of 148 unrelated male individuals from Spain. A total of 144 haplotypes were identified by the 17 Y-STR markers, of which 141 were unique, two were found in two individuals and one was found in three individuals. The haplotype diversity (99.95%) and discrimination capacity (97.30%) were calculated. Comparisons were made with previously published haplotype data on other Iberian population samples and no significant differences were found.  相似文献   
918.
Domestic dogs are increasingly involved, often as protagonists, in the forensic scene. Acknowledging this fact and benefiting from the accumulated experience on human mitochondrial DNA (mtDNA) analyses, we propose a standard for Canis familiaris mtDNA sequences as a prerequisite for the launching of the corresponding database.  相似文献   
919.
Collective poisoning with hallucinogenous herbal tea   总被引:1,自引:0,他引:1  
An incident wherein more than 30 people were poisoned with a herbal infusion during a meditation session is described. The clinical features observed were hallucinations, aggression, agitation, amnesia, mydriasis, dry skin, tachycardia, hyperthermia, hypotension, collapse, coma and respiratory depression. All patients recovered, although mechanical ventilation was required in some instances. A portion of the herbal infusion was found to contain atropine (hyoscyamine), scopolamine (hyoscine), harmine, and other alkaloids. The estimated ingested doses (free bases) were atropine 4 mg, harmine 27 mg, and scopolamine 78 mg. The mean concentrations in 21 serum samples obtained approximately 6h after ingestion of the infusion were atropine 5 ng/ml, harmine 8 ng/ml, and scopolamine 13 ng/ml.  相似文献   
920.
Efforts to prevent the spread of HIV infection sometimes give rise to tensions between individual and collective rights. This article, based on a presentation by Nelson Varas-Díaz (abstract TuOrG1171), explores these tensions in the context of the laws and policies of eight Latin American countries: Costa Rica, Dominican Republic, Ecuador, Guatemala, Honduras, Nicaragua, Panama, and Puerto Rico. The article describes five elements of the response to HIV/AIDS in which tensions between individual and collective rights have surfaced: the participation of people living with HIV/AIDS on national commissions; the ability of HIV-positive persons to access antiretroviral medications; HIV-antibody testing practices; the confidentiality of health information; and the rights and duties of people living with HIV/AIDS. The article concludes that the success of programs designed to prevent the spread of HIV infection depends on the ability of societies and governments to balance the tensions between individual and collective rights.  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