U阅迷你书房在公共图书馆的应用

U阅迷你书房是顺应时代为解决公共图书馆数字信息平台缺陷的创新产品。文章就U阅迷你书房自身定义的特点、与传统图书书籍的区别和对未来图书馆所造成的影响趋势这三个方面,从不同的角度详细论述了U阅迷你书房的优势及在未来被推广的必然性,从而阐明U阅迷你书房是公共图书馆发展所必不可缺的。     

Parental effects on crossability,embryo differentiation and plantlet recovery in wheat x rye hybrids

Summary One hexaploid wheat cultivar (Triticum aestivem) and two tetraploid wheat lines (T. durum) were crossed with seventeen inbred lines of rye (Secale cereale). Seed set, degree of hybrid embryo differentiation at the time of excision for in vitro culture and recovery of amphihaploid plantlets from various embryo categories were studied. Degree of embryo differentiation was predominantly determined by maternal wheats, paternal rye genotypes appearing to be of minor importance. T. aestivum x rye hybrid embryos were superior to those produced from T. durum for degree of differentiation. The proportion of plantlets developing from differentiated embryos was high for all wheat parents, whereas undifferentiated embryos were mostly unsuitable for plantlet production. The results revealed that cross-incompatibility in hexaploid wheat x rye crosses was due to failure of fertilization, while in tetraploid wheat x rye crosses it was caused by lack of embryo differentiation. Correlation analyses showed that seed set provided a criterion to predict the amphihaploid plantlets to be expected from a particular wheat x rye combination.     

“互联网+”时代中国成年人数字阅读行为特征的研究——基于第十二次至十六次国民阅读调查报告分析

文章主要采用文献调查法和数据对比分析法,以中国近5年全民阅读调查报告成年人数字阅读相关数据为基础,对中国成年人近5年数字阅读状况进行分析,发现中国成年人数字阅读行为具有时间碎片化、内容娱乐化以及形式多样化的特征。“互联网+”时代下中国成年人数字阅读浅表化现象严重、成人居民数字阅读娱乐化现象明显、成人数字阅读体验感有待提升,并对“互联网+”时代中国成年人数字阅读推广提出相对应的策略。     

嵌入式USB主机接口在温室环境监控中的应用研究

为了满足温室环境监控中大量信息存储的需要,研究了基于嵌入式USB主机接口的数据存储技术。该技术以51系列单片机为核心器件,嵌入了主/从双工作模式USB接口芯片SL811HS,并根据USB1.1协议和U盘文件系统格式,编制了USB接口驱动程序和数据存储应用程序。把该技术集成到自主开发的温室环境监控系统中进行了应用,实现了对目前市面上通用的64M、128M容量U盘的读写操作,解决了海量数据的存储问题。如果对驱动程序和应用程序做适当的修改,还可通过USB主机接口实现对USB接口打印机、USB接口扫描仪等外设的控制。结果表明,该数据存储方案具有成本低、通用性强、可扩展性强、可靠性高等特点,可方便地集成到各种监控系统中,从而满足用户的不同需要。     

海洋渔船RFID系统设计与防碰撞技术研究

为优化射频识别系统(RFID)性能,达到便捷高效管理和保障渔业安全生产,在对现有ALOHA算法的分析基础上,基于最优化原理提出一种改进型动态帧时隙ALOHA防避碰算法。该算法根据标签的数量动态,改变帧时隙的长度。运用改进的动态帧时隙算法对标签数量进行精确估计。通过仿真比较,在标签数量大量增加或者数量很少的情况下,改进后的算法使系统吞吐量最大达到了43%。当标签个数变化时,系统的吞吐量变化并不大;系统响应时延在标签数量变多的时候相比传统算法优势明显,响应时间几乎减少一半。相比传统算法,改进后的算法在系统吞吐量、系统响应时延等方面都有了明显的改善,提高了整个射频识别系统的性能,较好的适应了系统要求。     

Technical note: overcoming host contamination in bovine vaginal metagenomic samples with nanopore adaptive sequencing

Animal metagenomic studies, in which host-associated microbiomes are profiled, are an increasingly important contribution to our understanding of the physiological functions, health and susceptibility to diseases of livestock. One of the major challenges in these studies is host DNA contamination, which limits the sequencing capacity for metagenomic content and reduces the accuracy of metagenomic profiling. This is the first study comparing the effectiveness of different sequencing methods for profiling bovine vaginal metagenomic samples. We compared the new method of Oxford Nanopore Technologies (ONT) adaptive sequencing, which can be used to target or eliminate defined genetic sequences, to standard ONT sequencing, Illumina 16S rDNA amplicon sequencing, and Illumina shotgun sequencing. The efficiency of each method in recovering the metagenomic data and recalling the metagenomic profiles was assessed. ONT adaptive sequencing yielded a higher amount of metagenomic data than the other methods per 1 Gb of sequence data. The increased sequencing efficiency of ONT adaptive sequencing consequently reduced the amount of raw data needed to provide sufficient coverage for the metagenomic samples with high host-to-microbe DNA ratio. Additionally, the long reads generated by ONT adaptive sequencing retained the continuity of read information, which benefited the in-depth annotations for both taxonomical and functional profiles of the metagenome. The different methods resulted in the identification of different taxa. Genera Clostridium, which was identified at low abundances and categorized under Order “Unclassified Clostridiales” when using the 16S rDNA amplicon sequencing method, was identified to be the dominant genera in the sample when sequenced with the three other methods. Additionally, higher numbers of annotated genes were identified with ONT adaptive sequencing, which also produced high coverage on most of the commonly annotated genes. This study illustrates the advantages of ONT adaptive sequencing in improving the amount of metagenomic data derived from microbiome samples with high host-to-microbe DNA ratio and the advantage of long reads in preserving intact information for accurate annotations.     

绵羊实验性铅镉中毒及硒解毒时血液学指标的变化

12只健康成年绵羊随机分为3组,Ⅰ组口服醋酸铅和氯化镉溶液剂量为10mgPb／Kg·d和1mgCd／Kg·d,实验性制备出铅镉中毒模型;Ⅱ组除按Ⅰ组处理外,按0．1mgSe／Kg·d的剂量肌注0．2％亚硒酸钠生理盐水;Ⅲ组为健康对照组,测定各组主要血液学指标的变化。结果表明：试验开始后30d左右,Ⅰ组绵羊表现明显的中毒症状,精神沉郁,出现渐进性消瘦、贫血、腹泻和下颌水肿;Ⅱ组绵羊中毒症状较轻微。Ⅰ组绵羊的血红蛋向（Hb）、红细胞压积容量（PCV）和红细胞平均体积（MCV）均显著降低（P＜0．01或P＜0．05）,表现为低色素小细胞性贫血;Ⅰ、Ⅱ组绵羊碱性磷酸酶活性降低,尿素氮和谷草转氨酶活性的升高（P＜0．01或P＜0．05）;表明引起了肾脏及肝脏的损伤。     

RFID食品安全可追溯系统读取率优化策略研究

RFID食品安全可追溯系统应用的瓶颈之一是读取率问题.采用粗糙集理论渐进优化正交试验结果,对影响RFID系统读取率及读卡数的距离、偏离高度、速度、行数和列数等5个因素进行渐进正交试验优化,探索低成本RFID食品安全可追溯系统读取率及读卡数的优化策略.根据粗糙集理论的依赖度找出对读取率影响大的因素,重点搜索这些因素的水平值区间,反复调整水平值并进行正交试验,使结果逐渐逼近最优正交试验的水平组合.研究表明:粗糙集渐进优化正交试验方法能有效解决RFID系统读取率及读卡数的优化问题,读取率达到了99.3%以上.该成果为RFID系统的推广应用提供了有力的技术支持.     

钢琴基础教学中的几个问题

在钢琴基础教学中，教师应让学生掌握如何正确读谱，了解练琴的正确方法，以及培养学生独立学习的能力，重视整体音乐素质的提高，使学生从学琴之初就养成良好的学习习惯。     

浅析网络阅读

网络阅读是一种区别于传统阅读、新型并迅速流行的阅读方式,以海啸般的力量颠覆着国人的阅读习惯。但是由于互联网的新科技与海量信息而引发的这场阅读方式的革命中,所产生的＂读者导向＂现象,却产生了诸多问题,污染着读者的阅读空间。因此,本文将从网络阅读所带来的读者导向时代出发,分析这些现象产生的原因和暴露的问题,并提出了相应的解决措施,以期待能够净化网络阅读空间,营造更好的网络阅读环境。