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   11892篇
  免费   1249篇
各国政治   422篇
工人农民   385篇
世界政治   863篇
外交国际关系   303篇
法律   9080篇
中国共产党   1篇
中国政治   132篇
政治理论   1879篇
综合类   76篇
  2020年   338篇
  2019年   346篇
  2018年   395篇
  2017年   451篇
  2016年   465篇
  2015年   431篇
  2014年   424篇
  2013年   1200篇
  2012年   294篇
  2011年   376篇
  2010年   547篇
  2009年   492篇
  2008年   293篇
  2007年   251篇
  2006年   365篇
  2005年   246篇
  2004年   238篇
  2003年   226篇
  2002年   208篇
  2001年   444篇
  2000年   345篇
  1999年   300篇
  1998年   147篇
  1997年   135篇
  1996年   105篇
  1995年   136篇
  1994年   144篇
  1993年   118篇
  1992年   219篇
  1991年   236篇
  1990年   217篇
  1989年   230篇
  1988年   210篇
  1987年   181篇
  1986年   211篇
  1985年   229篇
  1984年   226篇
  1983年   188篇
  1982年   151篇
  1981年   133篇
  1980年   131篇
  1979年   150篇
  1978年   93篇
  1977年   79篇
  1976年   68篇
  1975年   73篇
  1974年   77篇
  1973年   65篇
  1972年   57篇
  1971年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Research into fingermark enhancement techniques has traditionally used visual comparisons and qualitative methods to assess their effectiveness based on the quality of the developed fingermark. However, with increasing research into the optimisation of these techniques the need for a quantitative evaluative method has arisen. Parameters for acceptable fingerprint quality are not well defined and generally encompass clear, sharp edges and high levels of contrast between the fingermark ridges and background material. Using these current parameters, a conclusive measurement of fingerprint quality and thus the effectiveness of development techniques cannot be achieved.This study presents a model through which an aspect of fingerprint quality can be objectively and impartially measured based on a relative contrast index, constructed through measuring the reflective intensity of the fingermark ridges against the background material. Using a fibre-optic spectrophotometer attached to a microscope with axial illumination, the intensity counts of the ridge detail and background material were measured and a logarithmic contrast index constructed. The microscope and spectrophotometer parameters were experimentally tested using a standard colour resolution chart with known reflective properties. The protocol was successfully applied to four sample groups: black inked fingerprints on white paper; latent fingermarks on white paper developed separately with ninhydrin and physical developer; and fingermarks in blood deposited on white tiles and enhanced with amido black. The contrast indices obtained quantitatively reflect the level of contrast and provide an indication of fingerprint quality through a numerical representation rather than previous qualitative methods. It has been suggested that the proposed method of fingerprint quantification may be viable for application in the forensic research arena as it allows the definitive measurement of contrast to aid the evaluation of fingermark detection and enhancement techniques.  相似文献   
952.
IN 2010, in the midst of economic turmoil, Irish society is enriched because of its close friendship with China and the Chinese people; a friendship that is based on mutual respect, cultural understanding and trust.  相似文献   
953.
954.
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   
955.
The article traces a large real and comparative decline in the rewards of high civil servants in Great Britain over the 20th century, accelerating since about 1970. It relates this to developments in the market for ‘high quality’ graduates and to changes in public and governmental attitudes which have affected the size, organization and role of the civil service. It discusses possible causes of the decline in top rewards in terms of three explanatory approaches suggested by social scientists – the ‘institutional’, the ‘cultural’, and the views of the ‘Chicago School’. Finally, following an examination of changes in the way senior British civil servants are now recruited and remunerated, it considers possible outcomes in terms of effects on the part they can play in the governmental process.  相似文献   
956.
957.
958.
959.
960.
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   
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