被子植物精细胞分离和特性研究进展     

朱维红  张妍  崔彬彬 《保定学院学报》2020,(3):114-121

精细胞分离是研究雄性生殖发育的前提之一,近半个世纪以来,人们运用不断更新的生物实验技术,对被子植物精细胞开展了分离及细胞分子特征的研究。分析被子植物精细胞分离方法,总结精细胞二型性与倾向性、细胞融合方面的研究成果,并对其研究意义和前景进行讨论。  相似文献   

The Use of Augmented Reality Technology in Medical Specimen Museum Tours     

Atsushi Sugiura  Toshihiro Kitama  Masahiro Toyoura  Xiaoyang Mao 《Anatomical sciences education》2019,12(5):561-571

Human anatomical specimen museums are commonly used by medical, nursing, and paramedical students. Through dissection and prosection, the specimens housed in these museums allow students to appreciate the complex relationships of organs and structures in more detail than textbooks could provide. However, it may be difficult for students, particularly novices, to identify the various parts of these anatomical structures without additional explanations from a docent or supplemental illustrations. Recently, augmented reality (AR) has been used in many museum exhibits to display virtual objects in videos captured from the real world. This technology can significantly enhance the learning experience. In this study, three AR-based support systems for tours in medical specimen museums were developed, and their usability and effectiveness for learning were examined. The first system was constructed using an AR marker. This system could display virtual label information for specimens by capturing AR markers using a tablet camera. Individual AR markers were required for all specimens, but their presence in and on the prosected specimens could also be obtrusive. The second system was developed to set the specimen image itself as an image marker, as most specimens were displayed in cross section. Visitors could then obtain the label information presented by AR without any markers intruding on the display or anatomical specimens. The third system was comprised of a head-mounted display combined with a natural click interface. The system could provide visitors with an environment for the natural manipulation of virtual objects with future scalability.  相似文献   

多旋翼无人机微多普勒特性分析与特征提取     

马娇  董勇伟  李原  李凌霄  杨杰芳 《中国科学院大学学报》2019,36(2):235-243

针对多旋翼无人机目标的识别问题，提出一种基于伽柏（Gabor）变换的瞬时频率估计与快速傅里叶变换（FFT）相结合的微多普勒特征提取算法。首先建立多旋翼无人机旋翼回波模型，并通过仿真分析叶片数目、旋翼转速和初始相位等参数对微多普勒特征的影响，利用Gabor变换得到时频特征。在此基础上通过瞬时频率极大值法提取微多普勒频率，并对瞬时频率采用FFT提取旋翼数和转动频率，从而获得叶片长度估计值。实测数据验证了该算法较为准确地提取无人机的微多普勒参数。  相似文献   

Syllable-based reading improvement: Effects on word reading and reading comprehension in Grade 2     

《Learning and Instruction》2020

This study examined the effects of a syllable-based reading intervention for German second graders who demonstrated difficulties in the recognition of written words. The intervention focused on fostering word reading via syllable segmentation. The materials consisted of the 500 most frequent syllables typically read by 6- to 8-year-old children. The aims were to practice phonological recoding, consolidate orthographic representations of syllables, and routinize the access to these representations. Compared to children randomly assigned to a wait-list group, poor readers in the treatment condition showed significant improvements in standardized measures of phonological recoding, direct word recognition, and text-based reading comprehension after the 24-session intervention. Poor readers in the treatment condition also showed greater improvements in development of word recognition compared to children with efficient word recognition skills. The results provide evidence that a syllable-based reading intervention is a promising approach to increase struggling readers’ word recognition skills, which in turn will improve their reading comprehension.  相似文献   

睡美人文献识别方法研究进展     

宗张建 《图书情报工作》2019,63(16):132-142

[目的/意义]睡美人文献是一类蕴藏着巨大科学价值的文献。对国内外睡美人文献识别方法的相关研究成果进行总结与梳理，形成比较完整的综述内容，为国内该领域研究提供参考与借鉴。[方法/过程]按方法属性将识别方法总结为4类，概括各识别方法的基本思路、识别标准、优点及局限性，并参照睡美人文献识别方法的4条原则进行对比，指出各识别方法的适用范围。[结果/结论]睡美人文献识别方法已由单一逐渐丰富，从主观参数向客观指标演变，从单一引文曲线向多种形式曲线并用发展。未来睡美人文献识别研究可从睡眠深度标准再定义、识别方法再组合上深入。此外，还需重视睡美人文献的定性研究和识别方法的验证性研究，重视睡美人引文价值的测度以及预测性研究。  相似文献   

The context dependence of physics identity: Examining the role of performance/competence,recognition, interest,and sense of belonging for lower and upper female physics undergraduates     

Zahra Hazari  Deepa Chari  Geoff Potvin  Eric Brewe 《科学教学研究杂志》2020,57(10):1583-1607

While there is a growing body of work that examines disciplinary identity development, unlike qualitative work in this area, quantitative research has not fully incorporated the importance of different contexts, nor has it uniquely focused on underrepresented groups (in this case, women in physics). This study examines how the constructs posited by prior work as important for physics identity, as well as an additional theorized construct, may interrelate and affect female students' physics identity differently depending on the context. Context in this study refers to two different experiential levels in college. The constructs examined include performance/competence, recognition, and interest, as well as sense of belonging. In particular, we used structural equation modeling to examine the effect that these constructs have on the physics identity of two groups of female physics undergraduates: first year students and senior year students. The results reveal that the relationship of the theorized constructs with physics identity vary between the two groups as well as compared to prior research with broad college student populations (not just physics majors). Unlike broad college student populations, for our sample of female physics undergraduates, interest did not have a direct effect on physics identity while sense of belonging was significant only for senior year students. These results exemplify the importance of examining context or different types of student experiences when studying disciplinary identity development rather than generalizing previous frameworks to all contexts.  相似文献   

浅谈东西方不同企业形象模式     

党明 《技术与创新管理》2006,27(4):109-109,112

鉴于企业形象识别中的主要部分——企业识别要素和企业形象设计在实际CI过程中和起主要作用,在此,针对企业识别要素和设计来进行探讨,并论述了企业形象设计发展和东西方的不同的企业形象模式的认识问题。  相似文献   

基于ART神经网络的中文文档分类识别方法研究     

王红 《情报理论与实践》2006,29(5):629-631,523

为了提高信息查询的效率，本文将自适应谐振神经网络引入中文文档搜索分类之中。在讨论自适应谐振神经网络基本原理的基础上，提出一种新的中文文档的层次聚类算法，从而提高中文文档的分类识别效率。  相似文献   

电子商务中基于深度学习的虚假交易识别研究     

刘畅  殷聪 《现代情报》2016,36(10):62

为了解决电子商务平台中存在的虚假交易问题,本文依据商品的销售记录以及商家的基本信息,提出了一种结合深度置信网络和多层感知器的虚假交易识别方法,通过识别出以通过刷单增加销量的商品来识别虚假交易。首先利用深度置信网络对交易特征进行学习,得到更高层次的抽象特征;然后利用多层感知器进行分类任务,从而识别出虚假交易。从淘宝中爬取商品的交易记录和评论数据进行实验验证,与其他机器学习模型的实验结果进行对比,其性能有明显的提升。  相似文献   

<Emphasis Type="Italic">Dis</Emphasis>closive Ethics and Information Technology: <Emphasis Type="Italic">Disclosing Facial Recognition Systems</Emphasis>     

Lucas?D.?IntronaEmail author 《Ethics and Information Technology》2005,7(2):75-86

This paper is an attempt to present disclosive ethics as a framework for computer and information ethics – in line with the suggestions by Brey, but also in quite a different manner. The potential of such an approach is demonstrated through a disclosive analysis of facial recognition systems. The paper argues that the politics of information technology is a particularly powerful politics since information technology is an opaque technology – i.e. relatively closed to scrutiny. It presents the design of technology as a process of closure in which design and use decisions become black-boxed and progressively enclosed in increasingly complex socio-technical networks. It further argues for a disclosive ethics that aims to disclose the nondisclosure of politics by claiming a place for ethics in every actual operation of power – as manifested in actual design and use decisions and practices. It also proposes that disclosive ethics would aim to trace and disclose the intentional and emerging enclosure of politics from the very minute technical detail through to social practices and complex social-technical networks. The paper then proceeds to do a disclosive analysis of facial recognition systems. This analysis discloses that seemingly trivial biases in recognition rates of FRSs can emerge as very significant political acts when these systems become used in practice. Paper prepared for the Technology and Ethics Workshop at Twente  相似文献