XYBM—1微机辅助编码系统

XYBW—1是无锡压缩机厂的成组分类编码系统,为了充分发挥其在该厂生产管理中的作用,开发了该系统的微机汉字辅助编码软件。该软件由 BASIC 程序和 dBASEⅢ数据库两部分组成。文章介绍了该系统的设计思想、系统的结构和所具有的功能,并用一个另件的编码实例对该软件的运行过程进行了说明。     

二级对角隐Runge-Kutta方法的B-收敛性

本文讨论了二级对角隐 Runge-Kutta 方法的 B-相容,B-稳定及 B-收敛性,导出了方法的1阶最优 B-收敛性,从而改进和推广了朱方生1988年的结果.本文讨论 B-相容,B-稳定性所用方法不同于 Dekker & Verwer 1984年的方法,所得误差估计较前更为精确,其中 B-稳定性的讨论也推广和修正了 Burrage & Butcher 1979年的结果.     

广东省入境旅游业发展差异时空演变研究

以广东省21地市为研究对象,基于1999—2009年数据,利用标准差、变异系数、集中指数、重心法、灰色关联分析等方法分析了广东省白1999年以来入境旅游发展差异的时空演变情况．结果表明：1）广东省入境旅游发展的绝对差异在不断扩大,相对差异呈缩小趋势,仇变幅较小,且入境旅游发展差异主要表现为珠三角内部地市之间的差异;2）广东省入境旅游发展差异的空间极化效应明显,发展极不平衡,集中度高,在空间上形成了明显的“双核四区（广州、深圳双核,珠三角、东翼、西翼、山区四区）”格局;3）灰色关联分析方法定量地揭示了广东省入境旅游发展地市差异与旅游资源分布的地市差异关联度不大,经济发展水平、区位条件、交通条件等是影响广东省各地市入境旅游业发展的主要因素．     

Repetitive motor learning induces coordinated formation of clustered dendritic spines in vivo

Many lines of evidence suggest that memory in the mammalian brain is stored with distinct spatiotemporal patterns. Despite recent progresses in identifying neuronal populations involved in memory coding, the synapse-level mechanism is still poorly understood. Computational models and electrophysiological data have shown that functional clustering of synapses along dendritic branches leads to nonlinear summation of synaptic inputs and greatly expands the computing power of a neural network. However, whether neighbouring synapses are involved in encoding similar memory and how task-specific cortical networks develop during learning remain elusive. Using transcranial two-photon microscopy, we followed apical dendrites of layer 5 pyramidal neurons in the motor cortex while mice practised novel forelimb skills. Here we show that a third of new dendritic spines (postsynaptic structures of most excitatory synapses) formed during the acquisition phase of learning emerge in clusters, and that most such clusters are neighbouring spine pairs. These clustered new spines are more likely to persist throughout prolonged learning sessions, and even long after training stops, than non-clustered counterparts. Moreover, formation of new spine clusters requires repetition of the same motor task, and the emergence of succedent new spine(s) accompanies the strengthening of the first new spine in the cluster. We also show that under control conditions new spines appear to avoid existing stable spines, rather than being uniformly added along dendrites. However, succedent new spines in clusters overcome such a spatial constraint and form in close vicinity to neighbouring stable spines. Our findings suggest that clustering of new synapses along dendrites is induced by repetitive activation of the cortical circuitry during learning, providing a structural basis for spatial coding of motor memory in the mammalian brain.     

Pragmatic Approach to Adaptive Turbo Coded Modulation

This paper presents a pragmatic adaptive scheme for TuCM over slowly fading channels. The adaptive scheme employs a single turbo coded modulator composed of a variable-rate turbo encoder and a variable-rate variable-power MQAM for all fading regions, so it has an acceptable complexity to implement. The optimal adaptive TuCM scheme is determined subject to various system constraints. Simulations have been performed to measure the performance of the scheme for different parameters. It is shown that adopting both the turbo coded modulator and the transmit power achieves a performance within 2.5 dB of the fading channel capacity.     

闭值域算子和框架的扰动

研究了B(H)上的闭值域算子的扰动问题,并把结果推广到框架理论.证明了当{fi}∞i＝1分别是H上的Bessel序列、框架或Riesz基,{gi}∞i＝1是一个序列,且{fi}∞i＝1和{gi}∞i＝1满足一定条件时,{gi}∞i＝1也分别是H上的Bessel序列、框架或Riesz基.     

船舶系统研制知识工程信息化平台建设

 船舶系统研制是一项典型的知识密集型的复杂工作，结合知识工程的具体实践，分析了知识工程体系的理论模型、建设内容和原则，探讨了知识工程信息化平台的构建，并展望了未来知识工程信息化的建设。应用本方法开展知识工程体系建设，可实现企业知识的有效获取和管理，促进知识与研发流程的关联应用，使得知识真正成为支撑企业发展的智力资产。     

Theoretical and experimental design of Pt-Co(OH)_2 electrocatalyst for efficient HER performance in alkaline solution

Design efficient electrocatalysts become significant for the hydrogen evolution reaction (HER) in alkaline solution.Here,the HER performance on Pt-Co(OH)2 has been investigated by using DFT calculations.Compared with pure Pt,the Pt-Co(OH)2 shows excellent hydrogen binding energy (-0.29 eV) and hydrogen adsorption free energy (0.02 eV).More strikingly,the water dissociation process on Pt-Co(OH)2 is an exothermic reaction while that of Pt is an endothermic reaction,demonstrating that the Pt-Co(OH)_2 is an excellent catalyst for HER in alkaline medium.Then the two-step electrodepositions was used to fabricate Pt-Co(OH)2 on the carbon paper (CP).The Pt-Co(OH)_2/CP shows the lowest overpotential of only 37.6 mV at a current density of 10 mA cm~(-2) in 0.1M KOH,the smallest Tafel slope of58 mV dec~(-1) and the good stability for 20000s without obvious degradation.     

开放式虚拟制造开发工具框架

相对集中式制造,提出开放式虚拟制造开发工具模型．给出虚拟制造开发工具的对象描述与应用系统的组成模式．说明微机上可实现的开发环境．制定虚拟制造开发工具中类定义格式,并举出两个对象的接口定义模型．在此基础上成功实现虚拟制造开发工具的理论原型．