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   545篇
  免费   22篇
各国政治   39篇
工人农民   43篇
世界政治   51篇
外交国际关系   29篇
法律   250篇
中国政治   9篇
政治理论   141篇
综合类   5篇
  2023年   5篇
  2021年   4篇
  2020年   13篇
  2019年   15篇
  2018年   19篇
  2017年   21篇
  2016年   20篇
  2015年   12篇
  2014年   13篇
  2013年   77篇
  2012年   23篇
  2011年   13篇
  2010年   8篇
  2009年   14篇
  2008年   15篇
  2007年   22篇
  2006年   12篇
  2005年   20篇
  2004年   17篇
  2003年   18篇
  2002年   18篇
  2001年   16篇
  2000年   12篇
  1999年   9篇
  1998年   7篇
  1997年   13篇
  1996年   6篇
  1995年   5篇
  1994年   12篇
  1993年   3篇
  1992年   6篇
  1991年   4篇
  1990年   12篇
  1989年   4篇
  1988年   8篇
  1987年   4篇
  1986年   4篇
  1985年   5篇
  1984年   8篇
  1983年   8篇
  1982年   4篇
  1981年   6篇
  1979年   7篇
  1978年   2篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
  1974年   3篇
  1970年   2篇
  1968年   2篇
排序方式: 共有567条查询结果,搜索用时 15 毫秒
91.
Despite numerous instrumental achievements, canines are still considered the most effective field method for explosive detection. However, due to strict explosive regulations and safety requirements, it can be a challenge for agencies with "bomb dogs" to train using neat explosive materials. This establishes a need for non-explosive canine training aids with the same volatile component profiles as the explosives that they represent. In order to compare mimic materials to their explosive counterparts, a technique must be established that not only allows for identification of volatile compounds but also can monitor changes in the headspace profile over time with respect to time and temperature. The Automated Training Aid Simulation using SPME (or ATASS) was developed for that purpose. As described, ATASS was used to observe changes in the volatile profile of three explosives (Composition C-4, 2,4-dinitrotoluene (DNT), and triacetone triperoxide (TATP)) and respective prototype training materials (0.1% by mass C-4, 1% by mass 2,4-DNT, and 1% by mass TATP). Samples were prepared in vials and metal tins within a gallon (≈ 3785 mL) paint can to simulate common field techniques for canine training. Monitoring these materials in real time provides a better understanding of the major volatile components present and how the relative abundances of these components can change over time. The results presented indicate that ATASS successfully allows for a sufficient comparison between explosive and non-explosive training materials.  相似文献   
92.
What is the role of stipends as an institutional facilitator in volunteer civic service? By examining the relationship of stipend receipt to volunteer diversity, time commitment, and perceived benefits from a longitudinal study of older adults serving in Experience Corps, this article assesses stipend status relative to volunteer sociodemographic characteristics, motivations, intensity and duration of time served, and volunteers’ self‐reported benefits. The findings underscore how stipends may promote participant diversity. In particular, stipended older adult volunteers serve for longer periods of time, but their motivations for serving do not differ. Stipended volunteers report higher perceived benefits than nonstipended volunteers. The results suggest that stipends may leverage wider inclusion, increase retention, and contribute to other benefits, but additional research is needed using more controlled and comparative designs.  相似文献   
93.
Sex determination is one of the essential steps in personal identification of an individual from skeletal remains. Most elements of the skeleton have been subjected to discriminant function analysis for sex estimation, but little work has been done in terms of the patella. This paper proposes a new sex determination method from the patella using a novel automated feature extraction technique. A dataset of 228 patellae (95 females and 133 males) was amassed from the William M. Bass Donated Skeletal Collection from the University of Tennessee and was subjected to noninvasive high resolution computed tomography (CT). After the CT data were segmented, a set of features was automatically extracted, normalized, and ranked. The segmentation process with surface smoothing minimizes the noise from enthesophytes and ultimately allows our methods to distinguish variations in patellar morphology. These features include geometric features, moments, principal axes, and principal components. A feature vector of dimension 45 for each subject was then constructed. A set of statistical and supervised neural network classification methods were used to classify the sex of the patellar feature vectors. Nonlinear classifiers such as neural networks have been used in previous research to analyze several medical diagnosis problems, including quantitative tissue characterization and automated chromosome classification. In this paper, different classification methods were compared. Classification success ranged from 83.77% average classification rate using labels from a Fuzzy C-Means (FCM) clustering step, to 90.3% for linear discriminant classification (LDC). We obtained results of 96.02% and 93.51% training and testing classification rates, respectively, using feed-forward backpropagation neural networks (NN). These promising results using newly developed features and the application of nonlinear classifiers encourage the usage of these methods in forensic anthropology for identifying the sex of an individual from incomplete skeletons retaining at least one patella.  相似文献   
94.
95.
Abstract

Other-deception and self-deception are important variables to consider when conducting a forensic psychological evaluation. The main aim of the present study was to investigate the effects of setting on other-deception and self-deception scores. It was hypothesised that patients at a maximum security hospital (Broadmoor) would score lower on an other-deception questionnaire than similar patients at a medium secure unit (Denis Hill Unit). All the patients completed the other-deception (ODQ) and self-deception (SDQ) questionnaires of Sackeim and Gur (1979) on admission to the two security hospitals. The Broadmoor patients (N = 46) obtained significantly lower ODQ score than the Denis Hill Unit (N = 52) patients, after controlling for differences in ethnic background and diagnosis among the two populations. No significant difference in setting was found for the SDQ score. The ODQ and SDQ scores were significantly associated with the type of diagnosis and the ethnic background of the patient, with patients diagnosed as mentally ill scoring higher than those with a diagnosis of personality disorder, and ethnic minority patients scoring higher than Caucasian patients.  相似文献   
96.
Abstract

Extensive social psychological research emphasises the importance of groups in shaping individuals' thoughts and actions. Within the child sexual abuse (CSA) literature criminal organisation has been largely overlooked, with some key exceptions. This research was a novel collaboration between academia and the UK's Child Exploitation and Online Protection Centre (CEOP). Starting from the premise that the group is, in itself, a form of social situation affecting abuse, it offers the first systematic situational analysis of CSA groups. In-depth behavioural data from a small sample of convicted CSA group-offenders (n =3) were analysed qualitatively to identify factors and processes underpinning CSA groups' activities and associations: group formation, evolution, identity and resources. The results emphasise CSA groups' variability, fluidity and dynamism. The foundations of a general framework are proposed for researching and assessing CSA groups and designing effective interventions. It is hoped that this work will stimulate discussion and development in this long-neglected area of CSA, helping to build a coherent knowledge-base.  相似文献   
97.
98.
In developing countries in particular, services are often delivered through unorthodox organisational arrangements that cannot simply be dismissed as relics of ‘traditional’ institutions, or as incomplete modern organisations. Some have emerged recently, and represent institutional adaptations to specific political and logistical circumstances. We need to expand the range of organisational categories that are considered worthy of study and develop a better understanding of the strengths and weaknesses of unorthodox arrangements. The concept of institutionalised co-production provides a useful point of entry. Institutionalised co-production is defined as: the provision of public services (broadly defined, to include regulation) through a regular long-term relationship between state agencies and organised groups of citizens, where both make substantial resource contributions. We explain some varieties of institutionalised co-production arrangements; explore why they appear to be relatively so widespread in poor countries; and relate the concept to broader ideas about public organisation.  相似文献   
99.
Joe Moore 《亚洲研究》2013,45(3):35-47
Abstract

Robert Cole points out in his introduction to Japanese Blue Collar that there are two dominant but conflicting views of the social relations of production in the Japanese economy, views which Cole conveniently sums up under the rubrics of “uniqueness” and “convergence.”  相似文献   
100.
Joe Arena 《政治交往》2013,30(3):345-346
Rosen, Jay. (1994). Making Things More Public: On the Political Responsibility of the Media Intellectual. Critical Studies in Mass Communication, 11(4), 363–388.  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