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   14518篇
  免费   139篇
各国政治   551篇
工人农民   449篇
世界政治   949篇
外交国际关系   462篇
法律   9864篇
中国共产党   1篇
中国政治   90篇
政治理论   2215篇
综合类   76篇
  2023年   66篇
  2021年   84篇
  2020年   392篇
  2019年   391篇
  2018年   462篇
  2017年   527篇
  2016年   539篇
  2015年   495篇
  2014年   489篇
  2013年   1408篇
  2012年   397篇
  2011年   456篇
  2010年   591篇
  2009年   544篇
  2008年   344篇
  2007年   330篇
  2006年   396篇
  2005年   277篇
  2004年   265篇
  2003年   264篇
  2002年   239篇
  2001年   473篇
  2000年   378篇
  1999年   317篇
  1998年   155篇
  1997年   132篇
  1996年   120篇
  1995年   141篇
  1994年   147篇
  1993年   123篇
  1992年   225篇
  1991年   239篇
  1990年   224篇
  1989年   238篇
  1988年   209篇
  1987年   182篇
  1986年   213篇
  1985年   232篇
  1984年   226篇
  1983年   193篇
  1982年   156篇
  1981年   133篇
  1980年   130篇
  1979年   154篇
  1978年   99篇
  1977年   84篇
  1976年   69篇
  1975年   73篇
  1974年   80篇
  1973年   65篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
261.
On the basis of prior research findings that employed youth, and especially intensively employed youth, have higher rates of delinquent behavior and lower academic achievement, scholars have called for limits on the maximum number of hours per week that teenagers are allowed to work. We use the National Longitudinal Survey of Youth 1997 to assess the claim that employment and work hours are causally related to adolescent problem behavior. We utilize a change model with age-graded child labor laws governing the number of hours per week allowed during the school year as instrumental variables. We find that these work laws lead to additional number of hours worked by youth, which then lead to increased high school dropout but decreased delinquency. Although counterintuitive, this result is consistent with existing evidence about the effect of employment on crime for adults and the impact of dropout on youth crime.
Gary SweetenEmail:
  相似文献   
262.
Der vorliegende Beitrag verfolgt die Zielsetzung die rechtliche als auch ökonomische Auffassung von Interessensabwägungen im öffentlichen Recht auf der Basis der Rechtsökonomie zusammenzuführen. Dafür wird die Abwägung von (konfligierenden) Interessen in einem juristischen Kontext diskutiert, in dem funktionelle und normative Anforderungen aufgezeigt werden und die juristische Sichtweise ausführlich erörtert wird. Anschließend werden im Rahmen einer rechtsökonomischen Antwort ökonomische Argumente und Instrumente vorgestellt, die es ermöglichen, eine übergeordnete Theoriesprache für den juristischen Abwägungsprozess zu definieren. Basierend auf diesem Schritt wird eine potenzielle Integration von Kosten Nutzen Analysen und Kompensationsmechanismen in den juristischen Abwägungsprozess besprochen.  相似文献   
263.
264.
Discharge planning is increasingly prioritized by correctional systems in order to prepare prisoners for their reintegration into society. A goal of discharge planning is to link prisoners with appropriate service providers in the community to meet their needs. A successful discharge plan requires that an optimal level of services exist and work in a coordinated and collaborative way in order to ensure a continuum of care and treatment during the reentry process (Queralt & Witte, 1999). This study utilized Geographic Information System (GIS) to assess the size, demographic characteristics, and needs of the Newark, New Jersey parolee population with the availability, location, and characteristics of health and human service agencies servicing their needs. A random sample of parolees (N = 800) released in 2006 was selected for this study. Social service agency data were obtained from an on-line service agency data base. Results of the analysis include the degree of spatial distribution, accessibility, and availability of services to where the parolees live and the degree of spatial overlap of specific services in an area.  相似文献   
265.
Current forensic DNA profiling methods rely on the analysis of samples at specialised laboratories with an average turnaround time of several days. The ability to rapidly determine a partial profile of short tandem repeats at the point-of-arrest would be of great benefit to police forces around the world, for example enabling a suspect to be rapidly included or excluded from an investigation. We have developed a homogeneous PCR method for the interrogation of STR loci utilising fluorescent oligonucleotide probes and melting curve analysis. Alleles of the D18S51, TH01 and D8S1179 loci were differentiated and identified on the basis of target length and probe melting temperature. Assay performance was evaluated by comparing melting peak data with the AmpFlSTR® SGM Plus® system. The method is compatible with direct analysis of unpurified buccal swab samples, enabling a partial STR profile to be generated within 1 h.  相似文献   
266.
Given that most fatal hangings are suicidal and occur in locations that have been selected to conceal this activity (thus maximizing the chances of a lethal outcome), there has been very little corroboration of the speed with which unconsciousness and death may occur. A 35-year-old male is reported who committed suicide by hanging immediately after talking to his spouse. Police investigations confirmed her reliability as a witness indicating that lethal anoxia in this case had occurred within a very short time (most likely in less than 1 min) of suspension. The speed with which death may result from hanging not only gives an insight into fatal pathophysiological mechanisms, but also provides useful information for situations where a lethal outcome is to be avoided, or is not intended. For example, individuals at risk of suicide who are being monitored in institutional facilities need to be constantly under direct visual surveillance as significant hypoxia can be rapidly induced, parents and caregivers with infants and children in potentially unsafe sleeping environments need to realize how swiftly death or irreversible anoxic brain damage may occur from neck compression, and those who engage in recreational asphyxia should be informed just how quickly a fatal outcome may ensue.  相似文献   
267.
The aim of the present study was to compare the accuracy, precision, and bias of two macroscopic and one histological age at death estimation methods on human teeth. The sample was comprised of 67 permanent teeth, obtained from 37 individuals aged 20-91 years. Age was predicted according to the methods proposed by Lamendin et al. (LAM), Bang and Ramm (BR), and the quantification of tooth cementum annulations (TCA). TCA was found to be most accurate in all age groups. Its mean absolute error of the estimated age was about half as high as the mean absolute error for both LAM and BR. BR achieved approximately the same mean absolute error as TCA for old adults only. LAM displayed the highest precision in the young and the old age group whereas TCA was more precise in the middle age group. TCA was found to be the most precise method when the precision was calculated for all ages. Considering the bias, all methods displayed a tendency to overestimate age in young and to underestimate it in old specimens. The exception to this rule was TCA, which provided unbiased estimates for young adults. The higher accuracy and precision recommends favouring TCA over LAM and BR, provided that the required know-how and equipment are available.  相似文献   
268.
The requirement to differentiate between incorporation and external contamination of drugs into hair is undisputed, in particular when dealing with compounds which are administered by sniffing or inhalation (e.g. cocaine). With the aim of making this discrimination, hair samples from cocaine (COC) users (group IN) and seized cocaine samples (group OUT) were compared regarding the parameters benzoylecgonine (BZE), ecgonine methyl ester (EME), ecgonine (ECG), anhydroecgonine methyl ester (AEME), cocaethylene (CE) and norcocaine (NCOC). Since most of these compounds may be minor by-products of COC or be formed by biotransformation or chemical degradation, the stability of each substance was carefully examined. COC was found to be converted into significant amounts of BZE, EME and ECG even under mild extraction conditions, while traces of NCOC proved to be a ubiquitous by-product of COC. Cocaine positive hairs and seized cocaine samples (diluted to relevant concentrations) were equally preprocessed and analyzed by LC-MS-MS. Out of the metabolites listed above, NCOC, CE and AEME (each normalised to COC) were significantly increased in the incorporation group (i.e. hair samples from cocaine users). Based on this approach, a statistical discriminant analysis enabled us to make a prediction (and estimation of uncertainty) for each cocaine positive hair sample as to its likelihood of belonging to the group of cocaine users or of being contaminated.  相似文献   
269.
The technique of principal component analysis has been applied to the UV-vis spectra of inks obtained from a wide range of black ballpoint pens available in the UK market. Both the pen ink and material extracted from the ink line on paper have been examined. Here, principal component analysis characterised each spectrum within a group through the numerical loadings attached to the first few principal components. Analysis of the spectra from multiple measurements on the same brand of pen showed excellent reproducibility and clear discrimination between inks that was supported by statistical analysis. Indeed it was possible to discriminate between the pen ink and the ink line from all brands examined in this way, suggesting that the solvent extraction process may have an influence on these results. For the complete set of 25 pens, interpretation of the loadings for the first few principal components showed that both the pen inks and the extracted ink lines may be classified in an objective manner and in agreement with the results of parallel thin layer chromatography studies. Within each class almost all inks could be individualised. Further work has shown that principal component analysis may be used to identify a particular ink from a database of reference UV-vis spectra and a strategy for developing this approach is suggested.  相似文献   
270.
Drawing on fieldwork and political theory with Lacanian psychoanalytic influences, this article analyzes how fantasy and fetishes help sustain strategies shown to be no solution to U.S. border control problems. More than a decade after the official launch of the border control paradigm of “prevention through deterrence,” predicated on the assumption that ramping up walls, barriers, policing, and the human costs of border crossing would deter, there has been scant evidence of deterrence and much evidence of diversion of migrants to more dangerous crossing points where death rates have soared. Attempts to mitigate the cost to life have also proved ineffective but have persisted alongside the policy of diversion. The article is based on research in a region where the reality of diversion and death instead of deterrence was lived but where people still pursue projects of barrier‐building and death mitigation that they know to be ineffective. The article analyzes how fantasy fuels action despite knowledge and occludes a traumatic element around which the symbolic order of border law is structured: the foundation of “good life” with its bounty of rights, privileges, and opportunity on the exclusion of basic life denuded of the entitlements that make the good life sweet. The article also examines how fetishes are used to cope with unrealized hopes and to diffuse the impact of the traumatic knowledge that good life is undergirded by the exclusion and even death of basic life.  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