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   1106篇
  免费   44篇
各国政治   53篇
工人农民   95篇
世界政治   91篇
外交国际关系   54篇
法律   608篇
中国共产党   2篇
中国政治   18篇
政治理论   191篇
综合类   38篇
  2023年   8篇
  2022年   8篇
  2021年   10篇
  2020年   27篇
  2019年   27篇
  2018年   39篇
  2017年   39篇
  2016年   53篇
  2015年   34篇
  2014年   37篇
  2013年   145篇
  2012年   46篇
  2011年   44篇
  2010年   43篇
  2009年   42篇
  2008年   45篇
  2007年   35篇
  2006年   38篇
  2005年   56篇
  2004年   51篇
  2003年   41篇
  2002年   36篇
  2001年   35篇
  2000年   31篇
  1999年   12篇
  1998年   24篇
  1997年   12篇
  1996年   8篇
  1995年   16篇
  1994年   8篇
  1993年   5篇
  1992年   4篇
  1991年   5篇
  1990年   8篇
  1989年   9篇
  1988年   8篇
  1987年   4篇
  1986年   10篇
  1985年   3篇
  1984年   4篇
  1983年   6篇
  1982年   5篇
  1981年   5篇
  1978年   4篇
  1977年   2篇
  1976年   3篇
  1974年   4篇
  1973年   2篇
  1972年   2篇
  1967年   3篇
排序方式: 共有1150条查询结果,搜索用时 15 毫秒
51.
A mobile and fast, semi-automatic ultrasound (US) system was developed for facial soft tissue depth registration. The system consists of an A-Scan ultrasound device connected to a portable PC with interfacing and controlling software. For 52 cephalometric landmarks, the system was tested for repeatability and accuracy by evaluating intra-observer agreement and comparing ultrasound and CT-scan results on 12 subjects planned for craniofacial surgery, respectively. A paired t-test evaluating repeatability of the ultrasound measurements showed 5.7% (n = 3) of the landmarks being significantly different (p < 0.01). US and CT-scan results showed significant differences (p < 0.01) using a Wilcoxon signed rank test analysis for 11.5% (n = 6) of the landmarks. This is attributed to a difference in the volunteer's head position between lying (CT) and sitting (US). Based on these tests, we conclude that the proposed registration system and measurement protocol allows relatively fast (52 landmarks/20 min), non-invasive, repeatable and accurate acquisition of facial soft tissue depth measurements.  相似文献   
52.
In a fire tragedy in Manila in December 1998, one of the worst tragic incidents which resulted in the reported death of 23 children, identity could not be established initially resulting in the burial of still unidentified bodies. Underscoring the importance of identifying each of the human remains, the bodies were exhumed 3 months after the tragedy. We describe here our work, which was the first national case handled by local laboratories wherein conventional and molecular-based techniques were successfully applied in forensic identification. The study reports analysis of DNA obtained from skeletal remains exposed to conditions of burning, burial, and exhumation. DNA typing methods using autosomal and Y-chromosomal short tandem repeat (Y-STR) markers reinforced postmortem examinations using conventional identification techniques. The strategy resulted in the identification of 18 out of the 21 human remains analyzed, overcoming challenges encountered due to the absence of established procedures for the recovery of mass disaster remains. There was incomplete antemortem information to match the postmortem data obtained from the remains of 3 female child victims. Two victims were readily identified due to the availability of antemortem tissues. In the absence of this biologic material, parentage testing was performed using reference blood samples collected from parents and relatives. Data on patrilineal lineage based on common Y-STR haplotypes augmented autosomal DNA typing, particularly in deficiency cases.  相似文献   
53.
54.
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.  相似文献   
55.
This study investigated to what extent abuse-related symptoms and family functioning are related to intra- or extrafamilial sexual abuse. One hundred adolescents (12 to 18 years old) were recruited shortly after disclosure of the abuse. Information from the participants was obtained through self-report questionnaires and a semistructured interview. Fifty-three percent of the adolescents reported clinically significant symptoms. Data did not support the idea that intrafamilial sexually abused adolescents report more symptoms than extrafamilial sexually abused adolescents. Type of abuse did not account for the differences and variety of reported symptoms or for differences in family functioning. Family functioning-in particular, lack of cohesion- was an independent contributor to internalizing trauma-related problems.  相似文献   
56.
57.
The “just war” philosophy of Cicero, St. Augustine, and St. Thomas Aquinas has had momentous and provocative implications for modern political theory. The use of force by police is one theme through which the just war tradition can be utilized to demonstrate the extent of infusion for the concept in the Western political archetype. As police become constrained in their use of force, they are bound by the concepts inherent in the philosophy of the just war doctrine. The Supreme Court, likewise, has been influenced by the philosophy of the just war tradition in many of its decisions regarding the proper use of force by police.  相似文献   
58.
59.
60.
Wagner WE 《Duke law journal》2004,53(6):1619-1745
One of the most significant problems facing environmental law is the dearth of scientific information available to assess the impact of industrial activities on public health and the environment. After documenting the significant gaps in existing information, this Article argues that existing laws both exacerbate and perpetuate this problem. By failing to require actors to assess the potential harm from their activities, and by penalizing them with additional regulation when they do, existing laws fail to counteract actors' natural inclination to remain silent about the harms that they might be causing. Both theory and practice confirm that when the stakes are high, actors not only will resist producing potentially incriminating information but will invest in discrediting public research that suggests their activities are harmful. The Article concludes with specific recommendations about how these perverse incentives for ignorance can be reversed.  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