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   393篇
  免费   16篇
各国政治   17篇
工人农民   11篇
世界政治   36篇
外交国际关系   25篇
法律   184篇
中国政治   1篇
政治理论   128篇
综合类   7篇
  2023年   2篇
  2022年   4篇
  2021年   4篇
  2020年   6篇
  2019年   9篇
  2018年   14篇
  2017年   13篇
  2016年   13篇
  2015年   8篇
  2014年   13篇
  2013年   68篇
  2012年   6篇
  2011年   4篇
  2010年   11篇
  2009年   9篇
  2008年   9篇
  2007年   14篇
  2006年   17篇
  2005年   9篇
  2004年   13篇
  2003年   9篇
  2002年   17篇
  2001年   6篇
  2000年   6篇
  1999年   5篇
  1998年   6篇
  1997年   9篇
  1996年   10篇
  1995年   2篇
  1994年   6篇
  1993年   4篇
  1992年   4篇
  1991年   7篇
  1990年   4篇
  1989年   7篇
  1988年   2篇
  1987年   3篇
  1986年   2篇
  1985年   7篇
  1984年   5篇
  1983年   6篇
  1982年   7篇
  1981年   6篇
  1978年   6篇
  1976年   2篇
  1975年   5篇
  1974年   2篇
  1973年   3篇
  1969年   1篇
  1968年   1篇
排序方式: 共有409条查询结果,搜索用时 15 毫秒
141.
142.
This article examines how communication patterns mediate the influences of values on political participation. We find that the positive effects of postmaterial values on participation are mediated through reading public affairs content in newspapers. In contrast, materialist values negatively affect participation through watching television entertainment. Interpersonal discussion in which disagreement occurs mediates both the positive effect of reading public affairs and the negative effect of materialism on political participation. We also provide what may be a better explanation of the influence of communication patterns on political participation by going beyond acquisition of factual political knowledge. We show that individuals' efforts to think about news and search for additional information and perspectives modify what people "get from" media. Reflecting about news and integrating information from various sources promote better understanding of the political world and may provide a stronger cognitive base for political participation than factual political knowledge.  相似文献   
143.
In the daily practice of forensic pathology, sudden cardiac death (SCD) is a diagnostic challenge. Our aim was to determine the usefulness of blood biomarkers [creatine kinase CK‐MB, myoglobin, troponins I and T (cTn‐I and T), and lactate dehydrogenase] measured by immunoassay technique, in the postmortem diagnosis of SCD. Two groups were compared, 20 corpses with SCD and 8 controls. Statistical significance was determined by variance analysis procedures, with a post hoc Tukey multiple range test for comparison of means (p < 0.05). SCD cases showed significantly higher levels (p < 0.05) of cTn‐T and cTn‐I compared to the control group. Although only cases within the first 8 h of postmortem interval were included, and the control group consisted mainly of violent death cases, our results suggest that blood troponin levels may be useful to support a diagnosis of SCD.  相似文献   
144.
Performance characteristics of commercial Y-STR multiplex systems   总被引:2,自引:0,他引:2  
In this work, a number of performance checks were carried out to evaluate the efficacy of commercial Y-short tandem repeats (Y-STR) kits for casework applications. The study evaluated the sensitivity, specificity and stability of the Y-STR markers used and the ability to obtain a male profile from postcoital samples taken at various time points after intercourse. All systems performed well with 1-3 ng of male DNA as recommended by the manufacturers. All systems gave full profiles at 100 pg of input DNA, which is within the realm of low copy number DNA analysis. Moreover all, except Y-Plex12, gave full profiles with 30-50 pg of male DNA. No increased performance was obtained with any of the systems by increasing the cycle number beyond that recommended by the various manufacturers. When up to 1 microg of female DNA was used (in the absence of male DNA) no female DNA cross reactivity was observed with the Y-Plex 12 and Y-Filer systems. PowerPlex Y produced female DNA derived products near the DYS438 and within the DYS392 loci at a rare allele position with high input DNA levels (300 ng and 1 microg, respectively). Male/female DNA admixture experiments indicated the particularly high specificity of the Y-Filer and PowerPlex Y systems under conditions of several thousand fold female DNA excess. All systems were able to detect the minor alleles in male/male DNA admixtures at a 1:5 dilution with the PowerPlex Y and Y-Filer being able to detect some minor alleles at 1:20. Species testing indicated some limited, minor cross reactivity of the commercial systems with some domestic male mammals although it is easily recognizable and would not pose any problems in casework analysis. As expected a significant number of cross-reacting products were obtained with nonhuman primate species. All Y-STR multiplex systems tested were able to produce complete Y-STR profiles from bloodstains and semen stains exposed up to 6 weeks when the samples were protected against precipitation and sunlight. However, exposure of the samples to precipitation either in the presence or absence of sunlight resulted in Y-STR profile loss over time, with total profile loss occurring with all systems after 3 weeks or more. Complete Y-STR profiles of the male donors up to 72 h postcoitus were obtained with all of the multiplex systems tested, except for Y-Plex12, which gave partial profiles.  相似文献   
145.
Simplified low-copy-number DNA analysis by post-PCR purification   总被引:5,自引:0,他引:5  
Frequently, evidentiary items contain an insufficient quantity of DNA to obtain complete or even partial DNA profiles using standard forensic gentotyping techniques. Such low-copy-number (LCN) samples are usually subjected to increased amplification cylces to obtain genetic data. In this study, a 28-cycle polymerase chain reaction (PCR) was used to evaluate various methods of post-PCR purification for their effects on the sensitivity of fluorophore-based allelic detection subsequent to capillary electrophoretic separation. The amplified product was purified using filtration, silica gel membrane, and enzyme mediated hydrolysis purification techniques and evaluated for their effect on fluorescent allelic signal intensity. A purification method was selected and its effect on fluorescent allelic signal intensity was compared with that of the unpurified PCR product. A method of post-PCR purification is described which increases the sensitivity of standard 28-cycle PCR such that profiles from LCN DNA templates (<100 pg DNA) can be obtained. Full DNA profiles were consistently obtained with as little as 20 pg template DNA without increased cycle number. In mock case type samples with dermal ridge fingerprints, genetic profiles were obtained by amplification with 28 cycles followed by post-PCR purification whereas no profiles were obtained without purification of the PCR product. Allele dropout, increased stutter, and sporadic contamination typical of LCN analysis were observed; however, no contamination was observed in negative amplification controls. Post-PCR purification of the PCR product can increase the sensitivity of capillary electrophoresis to such an extent that DNA profiles can be obtained from <100 pg of DNA using 28-cycle amplification.  相似文献   
146.
Jack Wallace   《Science & justice》2010,50(4):182-186
While forensic laboratories are coming under increasing pressure to provide meaningful estimates of measurement uncertainty, there has been little discussion of this topic in the literature. This article summarizes ten bases for estimating this parameter: (1) proficiency tests; (2) readability limits; (3) independent reference materials; (4) operational limits applied during calibration; (5) expert judgment; (6) precision control samples without (6) and with (7) contributions from extramural sources of error; (8) error budgets; (9) historical performance; and (10) ruggedness tests. Based on the assumptions underlying each approach, the forensic community will need to apply a variety of discipline-specific approaches to arrive at satisfactory estimates of measurement uncertainty.  相似文献   
147.
Many US veterans leave military service with a variety of psychosocial risk factors stemming from readjustment to civilian life, and there is increased public concern about the incarceration of veterans given ongoing conflicts in Iraq and Afghanistan. Prisons are playing instrumental roles in developing interventions to address the problems justice-involved veterans face both psychologically and environmentally in the form of veterans’ service units (VSUs), dormitories developed to assist with community reintegration, and connecting veterans to medical and mental health services. This study uses qualitative data from 87 veterans on a VSU who participated in a program improvement survey asking about their programming and reentry needs, experiences on the unit compared to other units, and any suggestions for improvement. Qualitative analysis of responses identified several themes including veterans’ needs around physical fitness, job training, education, and mental health and substance abuse treatment; positive experiences on the VSU compared to traditional units; the positive partnership role with the State Department of Corrections and the local Veterans Affairs (VA) medical center; and concerns on the unit about VA eligibility, combat status, and “real veterans.” These results are some of the first to capture the experiences of veterans on a VSU and the findings highlight potential benefits and challenges with implementing VSUs. Greater research and evaluation are needed to develop more treatment-oriented, rehabilitative models of justice and to continue to refine the VSU model.  相似文献   
148.
Although eyewitness memory and identification have captured substantial research interest in the past decades, an understanding of the types and prevalence of errors typically made by eyewitnesses is lacking. The purpose of the present research was to begin the development of a taxonomy of eyewitness error, employing standardized stimuli and established techniques. Respondents were exposed to a crime scene modeled on SWAT-training scenarios for systematically varied exposure times, and were then asked to describe what they had seen. The stimuli and questions employed were prepared with the aid of senior police field training officers. As anticipated, eyewitness performance in general was subject to a variety of inaccuracies. Physical errors, such as mistakes in the clothing or physical characteristics of the perpetrator, or in details of the environmental context, predominated. However, other less-expected errors were also observed: in relatively low numbers of cases, witnesses inferred emotional states or intent on the part of the perpetrator or victim. Some contributed wholly artificial backstories, reported the future actions of the perpetrator or victim as memories, or even inserted themselves into the scene. The pattern of results was shown to interact with exposure time, gender of the perpetrator, and the presence or absence of weapons in the scene. The results of this study are consistent with reconfigurative theory dating to Bartlett (1932), with subsequent research, and with more recent work under the aegis of Gestalt/Feature-Intensive Processing theory. These findings provide information on types and prevalence of eyewitness error which should prove useful in investigative and courtroom settings.  相似文献   
149.
One approach used to help find missing children is to place posters of them at the exits of supermarkets. The present research addresses the question of how effective that approach is likely to be. Posters of 8 missing children were displayed on a bulletin board at a cooperating grocery store. Customers leaving the store completed a survey and took a recognition memory test for the children. Most customers thought the problem of missing children was an important issue. However, the majority of customers also reported either not looking at the posters or only briefly looking at the posters. Recognition memory for children depicted in the posters did not reliably differ from chance. It appears that there is much room for improvement when it comes to increasing the attention paid to posters meant to help find missing children.  相似文献   
150.
In response to rising popular disenchantment with elected officials, numerous scholars have sought to defend politics and restate why it matters. For the most part, however, these theoretical arguments overlook the views and reflections of politicians themselves. As a step towards filling this gap, the author surveys politician-centred studies from around the world and the reflections of academics who have become politicians. By paying careful attention to what ‘insiders’ say about life in politics, the author constructs a practical rather than theoretical defence of the vocation and the people who undertake it. The author argues that politicians' views remind one that human endeavour is central to the purpose and function of politics and associated political institutions. To link the practical views and experiences of politicians with the emerging literature on demonisation, the author revisits the work of Arendt and Weber. The author concludes that while one may not always like who politicians are or the ways they operate, revaluing endeavour allows one to give credit where credit is due; politicians may regularly disappoint people but representative democracy does not work without them.  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