Nonlinearity degree of short-term heart rate variability signal

A nonlinear autoregressive (NAR) model is built to model the heartbeat interval time series and the optimum model degree is proposed to be taken to evaluate the nonlinearity degree of heart rate variability (HRV). A group of healthy persons are studied and the results indicate that this method can effectively get nonlinear information from short (6—7 min) heartbeat series and consequently reflect the degree of heart rate variability, which supplies convenience in clinical application. Finally, a comparison with the traditional time domain method shows that the NAR model method can reflect the complexity of the whole signal and lessen the influence of noise and instability, in the signal.     

Self-assembled structure of alkyloxy substituted benzoic acid methyl ester on HOPG：An STM study

Self-assembled structures of 3,4,5-tris-dodecy-loxy benzoic acid methyl ester (E12), 3,4,5-tris-tetradecy-loxy-benzoic acid methyl ester (E14) and their mixture (E12/E14) have been studied on HOPG by scanning tunneling microscopy (STM). Dimer-like patterns induced by dipole-dipole interaction are observed in E12 and E14 monolayers. The molecules form close-packed rows and interdigitate with the alkyl chains in adjacent molecules. The structural differences are proposed to be from the different length of substituted alkyl chains. Owing to similar adsorption energy, phase separation is observed in the E12 and E14 mixed adlayer with different domains.     

Relationship between Earth-Sun-Moon 1000 Ma ago： Evidence from the stromatolites

Stromatolitesareusuallyinterpretedastheorgano-sedimentarystructurescausedbythegrowthandmetabo-lismofmicro-organisms,principallycyanobacteriaandprecipitatedmineralgrainstrappedtothestickylay-ers[1—5].Asthesunlightisstrongindaytime,thealgaefila-mentsshowstrongactivityinphotosynthesisandgrowtowardsunlight.Ontheotherhand,asthesunlightisweakatnight,thealgaefilamentsshowinactivityinphotosyn-thesisandgrowhorizontally.Duringthecourseofgrowth,thealgaewillproducesomeglutinoussecretionwhichcancatchsedim…     

说"情趣"

我国古代文论对"情趣"的标树较晚,明清时期出现将"情"与"趣"纳入到诗歌审美质性要素系统或创作主体要素系统中的立论.但实际上,早从唐代开始,不少文论家就已经将"情趣"视为了"趣"的审美表现形态之一,对"情"与"趣"相互间的关系予以了多方面的考察.我国古代曾出现过很多"趣"的称名,其中,不少都可归入"情趣"这一审美形态中.     

Study on switched reluctance generator

The linear and non-linear math models of the switched reluctance generator (SRG) in generator mode were established in this work. The phase current and energy conversion process during generator operation were simulated by the linear math model. The non-linear math model was used to analyze the characteristics of the SRG operation in self-excitation mode and in separately-excitation mode. Some important findings on how the SRG is operated and controlled were obtained in this study, which provides theoretical basis for further design and experimental study.     

注意机制及其在模式匹配认知中的作用

引入注意函数,定量地描述\\"集中注意\\"的程度.它由系统内部的状态分布决定,并调控系统演化的规则,特别是调控系统对信息处理的策略,可称为自组织注意(或策略性注意),以别于一般所谓的选择性注意,且不需引入附加皮层.数值模拟表明,具有自组织注意机制可以很快捷有效地完成匹配任务,尤其是对输入有快速或突然变化时更为重要.     

深海沉积物样品中古菌的16S rDNA分析

利用多管采样器,在太平洋西经177°42'20",北纬10°35'06"的位置上,从水深5774 m的海底获得深海沉积物样本,现场提取DNA进行保存.以此DNA为模板,利用古菌16S rDNA特异引物扩增出样品中古菌的16S rDNA,将扩增所得的16S rDNA进行克隆,建立了该样品中古菌的16S rDNA文库.对16S rDNA扩增片段进行了RFLP分析和序列分析,结果表明这些古菌在系统进化树上的位置靠近,属于Crenarchaeota中的Ⅰ类海洋古菌类群.     

西南岩溶山区可持续发展战略面临的科技问题与对策

根据西南岩溶山区的地域环境特性,结合可持续发展的内涵,提出了西南岩溶山区实施可持续发展的战略目标和科技对策措施。指出西南岩溶山区应把生态建设和环境保护与科技水平的提高作为该地区可持续发展的切入点,大力加强相应的科学研究和科学规划。     

贵州岩溶山区旱地灌溉方式研究

贵州借助前人、同仁和本课题研究工作 ,对旱地灌溉方式问题进行几种不同的研究 ,向社会公诸一个解决贵州岩溶山区旱地灌溉的一种新思维方式 ,并提供旱地灌溉的一种最佳模式。即 :喷灌 +雨养模式 ,以此推荐一个 2 1世纪岩溶山区旱地农业产业化的基本模式 ,为推动旱地高效节水思路尽快转化为生产力服务。