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   5293篇
  免费   208篇
各国政治   287篇
工人农民   203篇
世界政治   412篇
外交国际关系   148篇
法律   3283篇
中国共产党   1篇
中国政治   33篇
政治理论   1098篇
综合类   36篇
  2020年   78篇
  2019年   90篇
  2018年   99篇
  2017年   130篇
  2016年   137篇
  2015年   119篇
  2014年   117篇
  2013年   618篇
  2012年   167篇
  2011年   138篇
  2010年   120篇
  2009年   113篇
  2008年   157篇
  2007年   151篇
  2006年   142篇
  2005年   138篇
  2004年   141篇
  2003年   133篇
  2002年   125篇
  2001年   190篇
  2000年   182篇
  1999年   134篇
  1998年   73篇
  1997年   56篇
  1996年   48篇
  1995年   59篇
  1994年   52篇
  1993年   50篇
  1992年   94篇
  1991年   88篇
  1990年   107篇
  1989年   89篇
  1988年   84篇
  1987年   84篇
  1986年   105篇
  1985年   109篇
  1984年   77篇
  1983年   81篇
  1982年   50篇
  1981年   49篇
  1980年   44篇
  1979年   48篇
  1978年   57篇
  1976年   35篇
  1975年   48篇
  1974年   61篇
  1973年   57篇
  1972年   42篇
  1970年   35篇
  1969年   41篇
排序方式: 共有5501条查询结果,搜索用时 15 毫秒
971.
Family‐centered care during adolescent detention aims to increase parental participation in an attempt to optimize treatment outcomes. However, little is known about parents’ needs in family‐centered care. To fill this gap, we interviewed 19 purposefully selected parents of detained adolescents using a semi‐structured topic list. Although needs differed between parents, they were generally interested in activities that included spending time with their child. It is important for parents to receive timely information about their child's condition and treatment, detention procedures, and activities in the facility. The outcomes demonstrated that parents expected a two‐way communication based on respect and reliability.  相似文献   
972.
973.
Soil vestiges might provide information about a crime scene. The Rietveld method with X‐ray diffraction data (RM‐XRD) is a nondestructive technique that makes it possible to characterize minerals present in the soils. Soil clays from the metropolitan region of Curitiba (Brazil) were submitted to DCB treatment and analyzed using XRD with CuKα radiation in the step‐scan mode (0.02° 2θ/5 s). The GSAS+EXPGUI software was used for RM refinement. The RM‐XRD results, together with the principal component analysis (PCA) (52.6% total variance), showed the kaolinite predominance in most analyzed samples and the highest quartz contents in “site 1.” Higher anatase, and gibbsite and muscovite contents influenced discrimination, mainly in “site 3” and “site 1,” respectively. These results were enough to discriminate clays of four sites and two horizons using a reduced amount of sample showing that the technique can be applied to the investigation into soil vestiges.  相似文献   
974.
A backspatter pattern results from blood drops that travel retrograde to an applied external force. Historically, an array of animals and nonhuman objects have been used to create and study backspatter patterns. In this study, backspatter patterns captured on foam core targets that were placed 45.72 cm (18 in) behind the impact site (occipital area of the skull) were produced by cranial gunshots to human cadavers that were reinfused with fresh defibrinated bovine blood. These patterns were compared to the backspatter patterns produced by shooting blood‐soaked sponges, a typical simulant used in controlled studies of backspatter pattern production and characteristics. The backspatter pattern produced by shooting an actual human head was found to be different than those of blood‐soaked sponges in the number of stains produced, the size and size range of the stains, and the stain dispersion patterns.  相似文献   
975.
976.
It is important to understand the extent of transfer of explosive particles to different surfaces in order to better evaluate potential cross-contamination by explosives in crowded security controls such as those at airports. This work investigated the transfer of nine explosive residues (ANFO, dynamite, black powder, TNT, HMTD, PETN, NH4NO3, KNO3, NaClO3) through fingerprints from one surface to another. First, the extent of adhesion of explosive residues from different surfaces to the bare finger, nitrile and latex gloves was studied. Then, the transfer of explosive residues from one surface to another through fingerprints was investigated. Cotton fabric (hereinafter referred to as cotton) as clothing material and polycarbonate plastic (hereinafter referred to as polycarbonate) as luggage material were chosen for the experiments. These surfaces containing explosive particles were imaged using a reflex camera before and after the particles were transferred. Afterwards the images were processed in MATLAB where pixels corresponding to explosive residues were quantified. Results demonstrated that transfer of explosive residues frequently occurred with certain differences among materials. Generally, the amount of explosive particles adhered to the finger decreased in the following order: skin>latex>nitrile, while the transfer of particles from the finger to another surface was the opposite. The adhesion of explosive residues from polycarbonate to the finger was found to be better compared to cotton, while the amount of particles transferred to cotton was higher.  相似文献   
977.
This paper examines police officer understandings of and attitudes to the sex offenders’ register, Violent and Sex Offenders’ Register (ViSOR) and Child Sexual Offender Disclosure Scheme (CSODS) in England and Wales – an under-researched area in the management of sexual offenders in the UK. This research is an adaptation of an American study utilising a mixed-methods approach, combining an online questionnaire survey (N?=?227) with a series of semi-structured interviews (N?=?27). The study found that police officers, irrespective of role, were generally supportive of the register, ViSOR and CSODS in principle, but they thought that logistics, practicalities, infrastructure, multi-agency collaboration and public understandings had problematic impacts on the scheme in practice. The participants believed that greater investment was needed in terms of time and resource to make the register, ViSOR and CSODS easier to use and access and thus fit for purpose.  相似文献   
978.
Soil traces are useful as forensic evidences because they frequently adhere to individuals and objects associated with crimes and can place or discard a suspect at/from a crime scene. Soil is a mixture of organic and inorganic components and among them soil clay contains signatures that make it reliable as forensic evidence. In this study, we hypothesized that soils can be forensically distinguished through the analysis of their clay fraction alone, and that samples of the same soil type can be consistently distinguished according to the distance they were collected from each other. To test these hypotheses 16 Oxisol samples were collected at distances of between 2 m and 1.000 m, and 16 Inceptisol samples were collected at distances of between 2 m and 300 m from each other. Clay fractions were extracted from soil samples and analyzed for hyperspectral color reflectance (HSI), X-ray diffraction crystallographic (XRD), and for contents of iron oxides, kaolinite and gibbsite. The dataset was submitted to multivariate analysis and results were from 65% to 100% effective to distinguish between samples from the two soil types. Both soil types could be consistently distinguished for forensic purposes according to the distance that samples were collected from each other: 1000 m for Oxisol and 10 m for Inceptisol. Clay color and XRD analysis were the most effective techniques to distinguish clay samples, and Inceptisol samples were more easily distinguished than Oxisol samples. Soil forensics seems a promising field for soil scientists as soil clay can be useful as forensic evidence by using routine analytical techniques from soil science.  相似文献   
979.
ABSTRACT

The purpose of the study is to examine the impact of a statewide intervention (BSW level Title IV-E Program) on both the workers’ intent to leave the job and their actual exit from a state administered public child welfare agency. Employees completed an extensive survey including scales assessing individual, team, and organizational variables that might impact turnover. Results show that more Title IV-E graduates stay with the agency than do regular hires and leave at a slower rate. Different variables impact intent to leave compared to actual exit and vary across type of employee. Implications for the workforce are discussed.  相似文献   
980.
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