基于ADS软件的微带滤波器的设计

传统的滤波器设计方法需要根据大量复杂的经验公式计算及查表来确定滤波器的各级参数,而采用ADS软件进行设计可以简化设计过程,提高设计效率,因此采用ADS软件设计了一个通带范围为2.3～2.4 GHz的微带滤波器,软件仿真达到性能指标后,进行了PCB板的制作,最后经硬件测试取得了良好的效果.     

Engagement with news on Twitter: insights from Australia and Korea

ABSTRACT

This study examines the patterns of news engagement among news consumers with different political affiliation and cultural background. We use computational methods and data from Twitter in a cross-country comparison of engagement with six online news sources in Australia and South Korea. For our analysis, we used a subset of Twitter users who retweeted at least one political story during the period of collection, and for whom we were able to predict political affiliation using correspondence analysis and data on Twitter follower ties to politicians. We find that right-wing Australian retweeters are more intense in their news engagement, compared with their left-wing counterparts, whereas in South Korea it was the opposite. Australian right-wing political retweeters have more diverse information sources, while there was no difference in information diversity between the right and left in South Korea. We discuss how the political situation in South Korea at the time of data collection may have affected our analysis. We emphasise the methodological contributions of our research and its connection to on-going research into the behavioural foundations of ‘filter bubbles’.     

卡尔曼滤波在多组分同时测定中的应用

卡尔曼滤波方法原理清晰，易实现计算机自动化，自行编制的卡尔曼滤波法计算机程序，计算速度快、精度高，其结果与文献值非常接近，实现了多组分的同时测定。     

基于多相滤波的正交器仿真分析

基于多相滤波的正交处理器技术是软件无线电技术的重要组成部分。本文对基于多相滤波的正交处理器进行了详细的研究，并给出了在MATLAB环境下的仿真结果。     

平滑Chahine迭代算法在光散射法粒度分布反演中的应用

光散射法粒度测试涉及到粒度反演技术.随着反演粒级数的增加,通常的粒度反演法将出现严重的振荡.文章将Chahine迭代算法与平滑滤波技术相结合解决了高反演粒级数下数值解的振荡,在不改变激光粒度仪的原有结构情况下,就可明显提高仪器的精度和分辨能力.     

一种简单的图像脉冲噪声滤除方法

针对传统的中值滤波法消除脉冲噪声时存在的缺陷,充分利用脉冲噪声的特征,提出了一种简单的噪声像素检测方法,在滤波处理前先检测像素是否被脉冲噪声污染,从而有选择地对噪声进行自适应中值滤波,该算法不仅能够有效滤除脉冲噪声,而且具有较少的计算量和较高的峰值信噪比。仿真结果证明了算法的有效性。     

苎麻/棉色织提花方格面料的设计

介绍了我国色织产品和苎麻纺织品的发展趋势,详细分析了苎麻/棉色织提花方格面料的设计和技术关键。     

Three-dimensional tracking of GLUT4 vesicles in TIRF microscopy

TIRF microscopy has provided a means to view mobile granules within 100 nm in size in two dimensions. However quantitative analysis of the position and motion of those granules requires an appropriate tracking method. In this paper, we present a new tracking algorithm combined with the unique features of TIRF. Firstly a fluorescence correction procedure was processed to solve the problem of fluorescence bleaching over time. Mobile granules were then segmented from a time-lapse image stack by an adaptive background subtraction method. Kalman filter was introduced to estimate and track the granules that allowed reducing searching range and hence greater reliability in tracking process. After the tracked granules were located in x-y plane, the z-position was indirectly inferred from the changes in their intensities. In the experiments the algorithm was applied in tracking GLUT4 vesicles in living adipose cells. The results indicate that the algorithm has achieved robust estimation and tracking of the vesicles in three dimensions.     

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.     

Virtual Dissection: An Interactive Anatomy Learning Tool

The novelty of three-dimensional visualization technology (3DVT), such as virtual reality (VR), has captured the interest of many educational institutions. This study’s objectives were to (1) assess how VR and physical models impact anatomy learning, (2) determine the effect of visuospatial ability on anatomy learning from VR and physical models, and (3) evaluate the impact of a VR familiarization phase on learning. This within-subjects, crossover study recruited 78 undergraduate students who studied anatomical structures at both physical and VR models and were tested on their knowledge immediately and 48 hours after learning. There were no significant differences in test scores between the two modalities on both testing days. After grouping participants on visuospatial ability, low visuospatial ability learners performed significantly worse on anatomy knowledge tests compared to their high visuospatial ability counterparts when learning from VR immediately (P = 0.001, d = 1.515) and over the long-term (P = 0.003, d = 1.279). In contrast, both low and high visuospatial ability groups performed similarly well when learning from the physical model and tested immediately after learning (P = 0.067) and over the long-term (P = 0.107). These results differ from current literature which indicates that learners with low visuospatial ability are aided by 3DVT. Familiarizing participants with VR before the learning phase had no impact on learning (P = 0.967). This study demonstrated that VR may be detrimental to low visuospatial ability students, whereas physical models may allow all students, regardless of their visuospatial abilities, to learn similarly well.