The Distribution of a CP-asymmetric quantity in the decay channel J / Ψ → π + π ? π 0

The distribution of a CP-asymmetric quantityA in the decay channelJ/ψ→π ⁺ π ⁻ π ⁰ is investigated. This dimensionless quantityA is constructed from the momenta of the π-meson final states, namely A=P _x ^{π +} P _y ^{π −} -P _x ^{π −} P _y ^{π −}, whereP _h,P _x ^h andP _y ^h are the module of the momentum of a hadron h, the x- and y-components of that momentum respectively, theJ/ψ particle is produced by e⁺ e⁻ collision, and the direction of the momentum of e⁺ is taken to be the positive direction ofz axis. There would exists the violation under the combined transformation of charge conjugation and space reflection (CP violation) when the average ofA among a lot of events, 〈A〉, be examined to be nonzero clearly from data. In this way, 748 events are selected from the BES experimental data, and analyzed. The corresponding averageA-value is measured to be 〈A〉 = 0.010 39 ± 0.014 61 ± 0.015 2. Further, some discussion of our result, the size of the data sample being need for further attempt and a possible perspective are given.     

一种有效的运动目标辨别方法

提出了一种利用图像序列中两帧相邻图像从分割所得二值图像的各个候选目标块中确定真实目标的有效算法．背景配准后，可获得背景噪声分布的直方图，同时获得具有对应关系的候选目标块间的噪声分布直方图，通过比较它们与背景噪声分布直方图之间的差异性，即可准确地辨别出真实目标．通过对实际图像序列进行实验，证实了本方法的有效性．     

Glycine binding primes NMDA receptor internalization

NMDA (N-methyl-d-aspartate) receptors (NMDARs) are a principal subtype of excitatory ligand-gated ion channel with prominent roles in physiological and disease processes in the central nervous system. Recognition that glycine potentiates NMDAR-mediated currents as well as being a requisite co-agonist of the NMDAR subtype of 'glutamate' receptor profoundly changed our understanding of chemical synaptic communication in the central nervous system. The binding of both glycine and glutamate is necessary to cause opening of the NMDAR conductance pore. Although binding of either agonist alone is insufficient to cause current flow through the channel, we report here that stimulation of the glycine site initiates signalling through the NMDAR complex, priming the receptors for clathrin-dependent endocytosis. Glycine binding alone does not cause the receptor to be endocytosed; this requires both glycine and glutamate site activation of NMDARs. The priming effect of glycine is mimicked by the NMDAR glycine site agonist d-serine, and is blocked by competitive glycine site antagonists. Synaptic as well as extrasynaptic NMDARs are primed for internalization by glycine site stimulation. Our results demonstrate transmembrane signal transduction through activating the glycine site of NMDARs, and elucidate a model for modulating cell-cell communication in the central nervous system.     

Geochronology of source materials from high-pressure and ultrahigh-pressure metamorphic rocks in Jurassic sedimentary rocks of Hefei Basin

Eclogite cobbles were discovered by Wang et al. (2001) in the Fenghuangtai Formation of the northern margin of Dabie Mountains in the Dushan area of Anhui Province, China[1]. They proposed that after the formation during the Triassic, the high-pressure (HP) and ultra-high-pressure (UHP) metamorphic rocks reached the sur-face through exhumation and uplifting before the late Ju-rassic. However, they have not provided any evidence about isotopic ages. One kind of cobbles of HP-UHP rocks w…     

陕西省兰科植物种类及其分布研究

对陕西省兰科植物种类及分布进行了调查研究.调查地点涉及兰科植物分布相对集中的30个县以及植物物种多样性相对丰富的15个自然保护区,野外调查在不同季节进行;分别对陕西省兰科植物进行了资源调查、标本采集和图片拍摄.对采集的标本通过查阅相关文献和与相关植物标本馆(室)兰科植物标本进行对比研究,共发现陕西省野生兰科植物41属82种,属、种数比以往的记录有大幅度增加.在此基础上,对陕西省兰科植物资源的合理开发、保护和管理提出了建议.     

厦门市林业有害生物普查结果及防控对策

2004—2005年，通过对厦门市林业有害生物的全面普查，共调查厦门市寄主树种130多种，查清了共有外来林业有害生物22种，本土有害生物25种。其中外来有害昆虫（线虫）4种，发生总面积246912．5亩；本土林业有害昆虫13种，发生总面积230273．5亩；外来有害植物18种，本土有害植物7种；本土有害危险性病原微生物5种。论述了厦门市林业有害生物发生原因，并提出厦门市目前的防控策略。     

前后台音响的实现

通过对ＰＣ机音响系统和内存驻留技术的研究，以Ｔｕｂｒｏ Ｃ为例，给出了前台和后台音响程序的操作方法。     

快速阅读的方法研究：信号词的识别

阅读理解已成为各级各类等级考试的主要内容，且分值比重也较高，如何提高阅读速度、提高阅读效果已成为教师和学生在教学和考试过程中都必须重视的问题，本文针对阅读理解文章的作者在创作过程中，为引起读者的注意而使用的信号词的类型。通过具体的相关实例，探讨了各种信号词的特点，通过归类分析可以帮助读者加快阅读速度和提高阅读理解力。     

联合收割机自动控制研究现状与展望

总结国内外联合收割机自动控制研究成果及存在问题，指出联合收割机智能模糊控制的发展趋势，提出适应我国国情的联合收割机智能模糊控制新模式为集中控制与分散监测相结合．