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   824篇
  免费   28篇
各国政治   39篇
工人农民   58篇
世界政治   97篇
外交国际关系   74篇
法律   367篇
中国共产党   4篇
中国政治   7篇
政治理论   199篇
综合类   7篇
  2023年   4篇
  2022年   8篇
  2021年   7篇
  2020年   35篇
  2019年   25篇
  2018年   33篇
  2017年   30篇
  2016年   22篇
  2015年   35篇
  2014年   26篇
  2013年   125篇
  2012年   19篇
  2011年   23篇
  2010年   31篇
  2009年   30篇
  2008年   24篇
  2007年   20篇
  2006年   26篇
  2005年   29篇
  2004年   25篇
  2003年   25篇
  2002年   16篇
  2001年   21篇
  2000年   30篇
  1999年   19篇
  1998年   17篇
  1997年   13篇
  1996年   11篇
  1995年   9篇
  1994年   9篇
  1993年   9篇
  1992年   7篇
  1991年   5篇
  1990年   7篇
  1989年   12篇
  1988年   10篇
  1987年   8篇
  1986年   5篇
  1985年   5篇
  1984年   8篇
  1983年   5篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   4篇
  1978年   2篇
  1977年   2篇
  1975年   2篇
  1974年   2篇
  1969年   2篇
排序方式: 共有852条查询结果,搜索用时 15 毫秒
111.
Initial reports of domestic violence are generally made to law enforcement officers who must respond and intervene. A subset of these episodes involves cases in which the victim, and, in many instances her child(ren), have been taken hostage by her husband or partner. Moreover, there are indications that the number of such incidents is growing. The purpose of this project was twofold: (1) to provide one of the first reports on the prevalence and characteristics of these events, and (2) to more closely analyze domestic crisis (hostage) situations using actual case examples. All information was obtained from the Hostage Barricade Database System (HOBAS) of the FBIs Crisis Negotiation Unit. HOBAS is a postincident information collection tool which stores historical data from law enforcement agencies across the nation on hostage/barricade incidents. An examination of this database yielded different types of domestic hostage-taking acts and outcomes (e.g., tactical vs. negotiated resolutions, survival vs. death/injury of perpetrator and/or victim[s]). Implications of the findings, for future crisis negotiation efforts directed toward nonviolent resolution of these high-risk critical incidents, are discussed.  相似文献   
112.
This article based, on 38 in-depth interviews with Rotterdam cocaine retail dealers, aims to present a clearer picture of how cocaine supply lines in the Netherlands are organized in order to fine-tune policy with respect to crime, public order and safety on the different trade levels. On the retail level the market for cocaine is strictly separated in a market for crack cocaine versus a market for powder cocaine. The crack dealers are often hard drug users themselves living in relatively poor circumstances. Although dealing cocaine is their main activity, they tend to be involved in other activities related to the drug scene, e.g. smuggling cocaine via Amsterdam airport. The cocaine distribution line for supply on the local market is seldom more than two steps. Because the supply for the Rotterdam cocaine retailers comes mainly from small-scale imports, successful police operations against large-scale imports of cocaine will have little influence on the local cocaine supply in the Netherlands.  相似文献   
113.

Objectives  

Report insights from the career of the noted evaluation researcher, Ted Palmer, on emerging issues in correctional research and correctional treatment.  相似文献   
114.
In prosecution, Belgian judiciary currently uses outdated yield figures (28.1g per plant, sold at € 3/g at grower level) for fining illicit indoor cannabis plantations. Using state-of-the-art cultivation techniques, our growth experiments showed that yield is better expressed in g/m(2) cultivated surface area rather than in g per plant, and that yield varies significantly between different cannabis strains. It was found that the lower-bound of the one-sided 95% confidence interval of the yield of an indoor cannabis plantation can be set at 575 g/m(2). Prices and pricing mechanisms were investigated using interviews with respondents selected through snowball sampling. Results reveal that (i) the Belgian cannabis market chain is highly complex; (ii) unit prices are predominantly determined by transaction sizes; but also (iii) a set of product- and socially-related price-fixing mechanisms have an equally important role. At grower level, respondents reported prices for 1 g of dry cannabis buds to range € 3.00-4.25.  相似文献   
115.
A collaborative study on Raman spectroscopy and microspectrophotometry (MSP) was carried out by members of the ENFSI (European Network of Forensic Science Institutes) European Fibres Group (EFG) on different dyed cotton fabrics. The detection limits of the two methods were tested on two cotton sets with a dye concentration ranging from 0.5 to 0.005% (w/w). This survey shows that it is possible to detect the presence of dye in fibres with concentrations below that detectable by the traditional methods of light microscopy and microspectrophotometry (MSP). The MSP detection limit for the dyes used in this study was found to be a concentration of 0.5% (w/w). At this concentration, the fibres appear colourless with light microscopy. Raman spectroscopy clearly shows a higher potential to detect concentrations of dyes as low as 0.05% for the yellow dye RY145 and 0.005% for the blue dye RB221. This detection limit was found to depend both on the chemical composition of the dye itself and on the analytical conditions, particularly the laser wavelength. Furthermore, analysis of binary mixtures of dyes showed that while the minor dye was detected at 1.5% (w/w) (30% of the total dye concentration) using microspectrophotometry, it was detected at a level as low as 0.05% (w/w) (10% of the total dye concentration) using Raman spectroscopy. This work also highlights the importance of a flexible Raman instrument equipped with several lasers at different wavelengths for the analysis of dyed fibres. The operator and the set up of the analytical conditions are also of prime importance in order to obtain high quality spectra. Changing the laser wavelength is important to detect different dyes in a mixture.  相似文献   
116.
Research has reported that not only characteristics of the perpetrator but also characteristics of the victim influence risk for intimate partner violence (IPV). This would suggest that prevention of repeat abuse could benefit from a focus on both perpetrator and victim characteristics. Knowledge on factors that are within victims' sphere of influence is important because a focus on victim characteristics can help victims to take control of their situations and can thereby empower them. Dynamic victim-related factors are most relevant here as these are factors that can be changed or improved, in contrast to unchangeable static factors. Surprisingly, however, little is known about how victim-related factors affect risk for revictimization of IPV. The current study was conducted among a Dutch sample of 156 female, help-seeking IPV victims. The aim was to examine to what extent prior IPV and, in particular, dynamic victim-related factors influence risk for future IPV. In accordance with the models articulated by Foa, Cascardi, Zoellner and Feeny, we studied how the three key factors from their models-partner violence, victims' psychological difficulties, and victims' resilience-related to risk for IPV revictimization. Results provide support for several key factors (partner violence and victims' psychological difficulties) and, moreover, show which victim-related factors contribute to revictimization risk above and beyond the influence of prior violence committed by a partner against the victim (i.e., victims' prior IPV victimizations). Findings are discussed in terms of recommendations for practice and future research.  相似文献   
117.
Urine is often the sample of choice for drug screening in aviation/general forensic toxicology and in workplace drug testing. In some instances, the origin of the submitted samples may be challenged because of the medicolegal and socioeconomic consequences of a positive drug test. Methods for individualization of biological samples have reached a new boundary with the application of the polymerase chain reaction (PCR) in DNA profiling, but a successful characterization of the urine specimens depends on the quantity and quality of DNA present in the samples. Therefore, the present study investigated the influence of storage conditions, sample volume, concentration modes, extraction procedures, and chemical preservations on the quantity of DNA recovered, as well as the success rate of PCR-based genotyping for DQA1 and PM loci in urine. Urine specimens from male and female volunteers were divided and stored at various temperatures for up to 30 days. The results suggested that sample purification by dialfiltration, using 3000-100,000 molecular weight cut-off filters, did not enhance DNA recovery and typing rate as compared with simple centrifugation procedures. Extraction of urinary DNA by the organic method and by the resin method gave comparable typing results. Larger sample volume yielded a higher amount of DNA, but the typing rates were not affected for sample volumes between 1 and 5 ml. The quantifiable amounts of DNA present were found to be greater in female (14-200 ng/ml) than in male (4-60 ng/ml) samples and decreased with the elapsed time under both room temperature (RT) and frozen storage. Typing of the male samples also demonstrated that RT storage samples produced significantly higher success rates than that of frozen samples, while there was only marginal difference in the DNA typing rates among the conditions tested using female samples. Successful assignment of DQA1 + PM genotype was achieved for all samples of fresh urine, independent of gender, starting sample volume, or concentration method. Preservation by 0.25% sodium azide was acceptable for sample storage at 4 degrees C during a period of 30 days. For longer storage duration, freezing at -70 degrees C may be more appropriate. Thus, the applicability of the DQA1 + PM typing was clearly demonstrated for individualization of urine samples.  相似文献   
118.
Most chemical and physical methods employed in visualizing latent marks have shown detrimental effects on human health and, therefore, some research groups have directed their attention to the utilization of various (bio)polymers with the aforementioned purpose. Although chitosan is widely used in medicine, pharmacy, food, and drug delivery systems, there are very few studies that address this biopolymer utilization in forensic applications, such as the detection of latent fingerprints. We used chitosan crosslinked with sodium tripolyphosphate and conjugated with L‐lysine to enhance the visualization of latent fingerprints, due to its ability to interact with fingerprint sweat residues. These conjugates were prepared using different (w/w) amounts of chitosan and tripolyphosphate (6/1; 4/1; 1/1; 1/4; and 1/6), and those with the most promising results (i.e., 6/1 formulation) were investigated in detail. Fourier transform infrared (FT‐IR) spectroscopy confirmed interactions between components of the systems. Optical microscopy and scanning electron microscope (SEM) analysis showed that prepared powder formulations were uniform in size and confirmed that chitosan/tripolyphosphate/lysine conjugates bind easily to the sweat and lipid residues present in the latent fingerprints. The testing of prepared conjugates demonstrated the potential of these systems as bio‐based powder substitution for commercially available powders.  相似文献   
119.
Young people who grow up in a violent family context are more vulnerable to become victims of sexual aggression outside the family context. The present study contributes to the understanding of the mechanisms that explain this link among young women by looking at the mediating role of sexual exposure behavior and target vulnerability. Data were used from an online survey among 237 young women aged 16 to 26 (M?=?21.0 years, SD?=?2.75). Experiencing violence from (one of) the parents and to a lesser extent witnessing interparental violence were related to an elevated risk for sexual victimization. Witnessing interparental violence was related to increased target vulnerability but this factor did not mediate the link with sexual victimization. Experiencing parental violence was related to both increased sexual exposure behavior and increased target vulnerability and these factors did mediate the link with sexual victimization.  相似文献   
120.
The present research adopts a multiple informant approach to identify victims and perpetrators of cyberbullying. Similar approaches have been successfully applied in the field of traditional bullying, and they are highly relevant for studying cyberbullying as well. Three informants can provide key perspectives on cyberbullying incidents: victims, perpetrators, and bystanders. To collect data on these actors, all eighth-grade students in 11 secondary schools were invited to participate in a survey. In total 1458 respondents completed peer-nomination questions on cyberbullying involvement. The results indicated that the prevalence of cyberbullying varied depending on the type of informants that was consulted. In addition, limited overlap was observed between the reports of different informants, resulting in different profiles of victims and perpetrators, depending on the informants that identified them. In sum, different informants tended to have divergent views on cyberbullying, which has important implications. It warrants accurate reporting and critical reflection on the sources of data in cyberbullying research. Moreover, it demonstrates the need to study a more diverse set of informants to advance the understanding of cyberbullying and to enhance prevention efforts.  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