共形空间${\mathbb Q}^{n+1}_1$中类空超曲面的拼挤问题

通过对第二共形基本形式的模长平方作拼挤,给出Clifford超柱面的一个共形特征.     

基于单片机和光电开关的通用计数器设计

At presrent, the photoelectric switch is more and more widely used in the industrial automation equipment.It can be finished counting industrial products by using the characteristic of the photoelectric switch which can detect the objects without touching them. This design uses the modular design method,including power-supply module, The photoelectric conversion module, optocoupler isolation circuit module, power off protection module, matrix keyboard module, counting module and The display module. It mainly uses 51 single-chip microcomputer to control the system,uses the keilC51 software to design program,uses the Proteus software to complete the simulation. Through the experiment, it proves the design is feasible.     

基于MEMS传感器的无线位置跟踪控制仿真应用

针对嵌入式工业控制系统终端显示的需要,提出了一种基于微处理器R1610和LCD控制器SSD1963的液晶显示模块的设计方法。详细阐述了硬件接口电路的设计和控制软件的编程,重点介绍了R1610、SSD1963以及TFT液晶屏AT070TN83之间的硬件连接方法,分析了SSD1963液晶控制的使用方法以及针对液晶屏显示时序的系统设置。结合显示控制实例实现了图像在液晶屏上的显示,显示效果良好。该显示模块的设计具有一定的应用前景和参考价值。     

Cycle-maximal triangle-free graphs

We conjecture that the balanced complete bipartite graph _{K⌊n/2⌋,⌈n/2⌉}$K_{\lfloor n/2\rfloor ,\lceil n/2\rceil }$ contains more cycles than any other n$n$-vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds on the numbers of cycles in graphs depending on numbers of vertices and edges, girth, and homomorphisms to small fixed graphs; and use the bounds to show that among regular graphs, the conjecture holds. We also consider graphs that are close to being regular, with the minimum and maximum degrees differing by at most a positive integer k$k$. For k=1$k=1$, we show that any such counterexamples have n≤91$n\le 91$ and are not homomorphic to _C5$C_5$; and for any fixed k$k$ there exists a finite upper bound on the number of vertices in a counterexample. Finally, we describe an algorithm for efficiently computing the matrix permanent (a #P$\#P$-complete problem in general) in a special case used by our bounds.     

通过赝反伽伐尼反应实现金纳米粒子模块替换

通过可控的方式精确调控纳米粒子的结构仍是一个富有挑战性和鼓舞人心的课题.尽管单原子或两、三个金属原子的精细调控已经在金纳米粒子中实现,涉及三个以上金属原子的取代（模块取代）还没有报道.本工作报道了环己硫醇配体保护的Au₄₈（CHT）₂₆的合成及其通过赝反伽伐尼过程的模块取代.单晶结构揭示模块取代的产物与母体团簇共用一个相似的Au₃₁（CHT）₁₂主体,但剩余部分不同（Au₆（CHT）₁₁ vs.Au₁₆（CHT）₁₄）.一个有趣的发现是模块取代抑制了Au₄₈（CHT）₂₆的光热过程,却增强了它的发射,赋予了所合成团簇更好的双（多）功能应用潜力.光热效应的减弱和发射的增强也暗示了这两种作用能够彼此至少部分转化,对于研究这两种效应之间的相互影响也具有重要的启示.     

形式三角矩阵环上的有限表示模

形式三角矩阵环,又称广义三角矩阵环,这类环及其上的模在环模理论中扮演着重要的角色.本文对形式三角矩阵环上的有限表示模进行了一些探讨.     

基于S域RLC传输线模型的多芯片组件互连功耗计算

为了分析多芯片组件的互连功耗,用RLC传输线模型对多芯片组件的互连进行表征,通过对输入互连的电流及其等效电阻的近似,推导出多芯片组件互连功耗的频域数学表达式,给出计算机仿真试验结果,对方法的有效性进行验证.     

Comment on “Kirchhoff index in line,subdivision and total graphs of a regular graph”

Let G$G$ be a connected regular graph. Denoted by t(G)$t\left(G\right)$ and Kf(G)$Kf\left(G\right)$ the total graph and Kirchhoff index of G$G$, respectively. This paper is to point out that Theorem 3.7 and Corollary 3.8 from “Kirchhoff index in line, subdivision and total graphs of a regular graph” [X. Gao, Y.F. Luo, W.W. Liu, Kirchhoff index in line, subdivision and total graphs of a regular graph, Discrete Appl. Math. 160(2012) 560–565] are incorrect, since the conclusion of a lemma is essentially wrong. Moreover, we first show the Laplacian characteristic polynomial of t(G)$t\left(G\right)$, where G$G$ is a regular graph. Consequently, by using Kf(G)$Kf\left(G\right)$, we give an expression on Kf(t(G))$Kf\left(t\left(G\right)\right)$ and a lower bound on Kf(t(G))$Kf\left(t\left(G\right)\right)$ of a regular graph G$G$, which correct Theorem 3.7 and Corollary 3.8 in Gao et al. (2012)  [2].