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   66篇
  免费   1篇
  国内免费   28篇
教育   45篇
科学研究   39篇
各国文化   3篇
体育   2篇
综合类   1篇
信息传播   5篇
  2021年   3篇
  2020年   6篇
  2019年   2篇
  2018年   3篇
  2017年   1篇
  2016年   4篇
  2015年   2篇
  2014年   3篇
  2013年   6篇
  2012年   2篇
  2011年   5篇
  2010年   2篇
  2009年   5篇
  2007年   2篇
  2006年   4篇
  2005年   5篇
  2004年   3篇
  2003年   2篇
  2001年   1篇
  2000年   2篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1991年   2篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1984年   3篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1979年   3篇
  1978年   2篇
  1966年   1篇
排序方式: 共有95条查询结果,搜索用时 15 毫秒
81.
82.
This study presents a novel approach to decant supernatant on a centrifugal platform. By manipulating the centrifugally induced pressure and the elastic deformation of the plastic lids in the decanting chamber, fixed amounts of the supernatant can be decanted into the detection chamber at lower rotational speeds. The experimental results showed that decanted volume is affected by the volume of deformation and the operating parameters. Factors that influence the decanting ratio are also discussed. This approach has the advantages of simple design and low manufacturing cost; further, it has no need of surface modification. It has been applied to on-disk separation of plasma from whole blood, and the results showed good stability and repeatability.  相似文献   
83.
INTRODUCTION The conventional design of rails uses steel clipboards and bolts to link rails, and avoids bucklingcaused by thermal expansion effect by mountingexpansion joints to solve axial restraint generated byseasonal or day-and-night temperature changes. Butthe discontinuity at the rail joints brings discomfortand noise to passengers when the train has suddenlystops or starts, during which train speed cannot beeffectively increased, rails are more easily damaged,and the cost of mainte…  相似文献   
84.
85.
 本文采用狭义概念,将苦荬菜类群(Ixeris group)处理为4个属,即苦荬菜属Ixeris Cass.沙苦荬属Chorisis DC.小苦荬属Ixeridium(A.Gray)Tzvel.及黄瓜菜属Paraixeris Nakai并提供了分属、种检索表。文中记载了3个新种及7个新组合种。  相似文献   
86.
87.
Abstract

Gyro sensor has been used to measure foot pronation during running with reliable results in previous studies, and the signals were not affected by the vibration of heel strikes. The purpose of this study was to observe the kinematic changes of the foot during intense running using a 3-axis gyro sensor. Fifteen male participants (average age: 24.5 ± 1.7 years; mean height: 174.1 ± 3.3 cm; mean body weight: 71.0 ± 5.5 kg) were recruited in this study. Foot kinematic changes were observed in 30-min intense running protocols. The comparisons of the signals from gyro and motion analysis system were also performed to determine the accuracy of the gyro and showed positive results. In the main experiment, the ankle range of motion (ROM) in the frontal plane, measured using a motion system, showed a significant increase over time. Accordingly, peak angular velocity in the frontal plane also showed a significant increase. The correlation between ankle ROM and peak angular velocity in the frontal plane is significantly high (= 0.975). Moreover, peak angular velocity in the frontal plane is also significantly correlated with both rate of perceived exertion (RPE) (= 0.911) and heart rate (= 0.960). This study concluded that an alarm system for foot kinematic changes related to running injuries can be built based on the peak angular velocity of the foot in the frontal plane.  相似文献   
88.
In-depth interviews and genre analysis were conducted to derive the genre characteristics of commercial and noncommercial Internet book reviews in order to explore the judgment criteria for commercial (i.e., fake) and noncommercial (i.e., authentic) Internet book reviews. An empirical investigation was then performed to confirm which genre characteristics could serve as judgment criteria. Results indicated that structure and format, attributes of content, information orientation, number of words, lexical richness, personal pronouns, and paralinguistic features can provide useful clues to judgments. Moreover, commercial Internet book reviews with certain genre characteristics may hide their commercial intentions. These findings can provide reference for judgment criteria for online readers or librarians who want to select books based on objective book reviews, or on Internet bookstore marketing strategies that focus on electronic word-of-mouth comments.  相似文献   
89.
Learning disabilities (LD) has been recognized as a category of special education in Taiwanese law since 1984, and policies ensure educational services for children and youth who have LD. The official definition and identification criteria established in Taiwan's laws closely correspond with those of the United States, but practice differs, largely influenced by the people's cultural and linguistic background. I discuss these legal and cultural features as well as other matters (e.g., growth and change in professional literature on LD). Compared to economically developed countries such as the United States, the educators in Taiwan implement identification procedures, placement, and services at a lower cost. Contents of implementation are introduced in detail. The prevalence rate of LD has been very low (<1 percent). I examine culture‐ and/or society‐specific reasons for low prevalence, such as Chinese orthography, regular teachers' compliance with referral procedures, the education‐first belief of parents, and problems with identification procedures.  相似文献   
90.
Images with human faces comprise an essential part in the imaging realm. Occlusion or damage in facial portions will bring a remarkable discomfort and information loss. We propose an algorithm that can repair occluded or damaged facial images automatically, named ‘facial image inpainting'. Inpainting is a set of image processing methods to recover missing image portions. We extend the image inpainting methods by introducing facial domain knowledge. With the support of a face database, our approach propagates structural information, i.e., feature points and edge maps, from similar faces to the missing facial regions. Using the interred structural information as guidance, an exemplar-based image inpainting algorithm is employed to copy patches in the same face from the source portion to the missing portion. This newly proposed concept of facial image inpainting outperforms the traditional inpainting methods by propagating the facial shapes from a face database, and avoids the problem of variations in imaging conditions from different images by inferring colors and textures from the same face image. Our system produces seamless faces that are hardly seen drawbacks.  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