Phase Propagations in a Coupled Oscillator-Excitor System of FitzHugh-Nagumo Models

A one-dimensional array of 2N ＋ 1 automata with FitzHugh-Nagumo dynamics, in which one is set to be oscillatory and the others are excitable, is investigated with hi-directional interactions. We find that 1 ： 1 rhythm propagation in the array depends on the appropriate couple strength and the excitability of the system. On the two sides of the 1 ： 1 rhythm area in parameter space, two different kinds of dynamical behaviour of the pacemaker, i.e. phase-locking phenomena and canard-like phenomena, are shown. The latter is found in company with chaotic pattern and period doubling bifurcation. When the coupling strength is larger than a critical value, the whole system ends to a steady state.     

国际市场营销管理与决策信息系统(IMMADIS)原型研究

分析归纳了国际市场营销管理与信息的特征，把系统目标分解为三级，依此提出的国际市场营销管理与决策信息系统结构模式，充分考虑了计算机在企业管理中应用的优势与特点，同时又考虑到国情，便于企业开发实施。     

ON A CLASS OF METHOD FOR SOLVING PROBLEMS WITH RANDOM BOUNDARY NOTCHES AND/OR CRACKS-(Ⅳ)Computations for Deep Boundary Notches and/or Cracks

This paper continues the discussions to a class of method for solving problems withrandom boundary notches and/or cracks in references by C.Ouyang in [1](See also[2]and[3]).Using the basic method given in this reference as well as some further developments.We develop here a new effective computational method for solving random deep boundarynotches and/or cracks.The actual numerical computations given in this paper show that thepresent method is quite workable and the results obtained have enlarged the contents of“Handbook of Stress Intensity Factors”given by G.C.Sih.     

基于高光谱图谱融合技术的黄桃损伤程度判别研究

黄桃含有丰富的营养物质,深受消费者的喜爱。但在加工运输的过程中极易受到碰伤,给果农和销售商带来极大地经济损失。以往利用高光谱技术检测水果碰伤,通常是仅仅利用光谱信息或者图像特征建立水果碰伤检测模型,很少将图谱融合用于水果碰伤的检测。光谱反射率容易受到外界杂散光的影响,会丢失一部分真实信息,图像包含的信息量较少,仅仅只靠几个特定波段的图像很难精准识别。因此,为了实现对黄桃碰伤程度的精准分类,从而可根据不同碰伤程度的黄桃制定不同的处理方式,减小经济损伤。提出一种利用高光谱的光谱信息结合图像特征建立模型来检测不同碰伤程度的黄桃。以180个黄桃作为实验样品,首先分别采集轻度、中度和重度碰伤黄桃的高光谱图像,在每个黄桃的碰伤位置选取100×100像素的区域作为感兴趣区域,利用ENVI4.5软件提取碰伤区域的光谱信息。然后采用主成分分析(PCA)算法对采集的高光谱图像进行降维处理,在前5个PC图像中最终选择PC1图像作为黄桃碰伤的主成分图像,根据PC1图像的权重系数曲线挑选出6个特征波长对应的图像作为特征图像,将平均灰度值作为黄桃碰伤的图像特征。最后,分别利用光谱信息、图像特征、光谱信息结合图像特...     

第一类曲面积分的新方法

从一个具体的物理问题入手,探讨了如何将第一类曲面积分转化为两个第一类曲线积分的累次形式,从而给出了这两类积分之间的关系,并通过举例说明该公式可以用来直观简便地计算第一类曲面积分.     

On a class of method for solving problems with random boundary notches and/or cracks

As we know,problems with boundary imperfections(notches or cracks)are the more importantone in practical fracture analysis.Frequently,these imperfections would appear in the boundaries ofthe bodies as a randomly distributed group,and under the loading circumstances would grow up to beunstable cracks which induces catastrophic fracture of the bodies.For right evaluation the fracturebehavior of the bodies with such boundary imperfections,it demands mathematical solutions for pro-blems with random boundary notches and/or cracks.     

N-O螯合配体协同膦配体的银(Ⅰ)混配配合物的设计、结构和生物活性

合成了一种Ag （Ⅰ）配合物[Ag （Qina）（Tpp）₂]·1.5H₂O （Qina=2-喹啉羧酸根,Tpp=三苯基膦）。运用单晶X射线衍射、IR、NMR和粉末X射线衍射对配合物的结构进行了表征。配合物属于单斜晶系,C2/c空间群,晶胞参数：a=3.195 90（13） nm,b=1.210 96（4） nm,c=2.319 74（7） nm,β=102.166（4）°,V=8.776 0（5） nm³,Z=8。通过Hirshfeld表面分析,推导出配合物的超分子结构和分子间弱作用力。同时,通过DNA结合活性测试、抗菌活性和癌细胞体外毒活性测试,评价了配合物的生物活性。     

镧掺杂锡酸钡/多壁碳纳米管改性隔膜的制备及其在锂硫电池中的应用

通过将共沉淀法制备的钙钛矿型氧化物镧掺杂锡酸钡(LBSO)与多壁碳纳米管(MCNT)混合均匀,制成浆料,并利用刮涂法将其涂布在商业隔膜Celgard 2500(PP)表面构筑阻挡层,获得改性隔膜(LBSO/MCNT/PP)。基于该改性隔膜的锂硫电池在0.1C下具有高达1 433 mAh·g^-1的初始放电比容量,1C时300次循环后每圈容量衰减率为0.114%;当电流密度提高到3C时,仍具有764 mAh·g^-1的放电比容量,表现出优良的倍率性能和循环稳定性,这主要是由于该阻挡层能够有效抑制多硫化物的穿梭。     

激光脉冲的横向波形对弓形波电子俘获的影响

用粒子模拟研究了在激光尾波场电子弓形波注入过程中激光脉冲的横向波形对尾波场俘获电子数目的影响, 发现与高斯激光相比, 超高斯形激光更有利于拉动空泡闭合前侧边的电子团向空泡尾部汇聚形成高能量局域化的弓形波, 从而导致更多的电子注入到空泡的加速相, 使得被俘获的电子数目提高近5倍, 且电子束品质得到改善.该研究对于进一步理解尾波场加速中电子注入等有参考价值. 关键词： 尾波场 电子俘获 横向波形 粒子模拟     

Hexagonal Standing-Wave Patterns in Periodically Forced Reaction-Diffusion Systems

The periodically forced spatially extended Brusselator is investigated in the oscillating regime. The temporal response and pattern formation within the 2：1 frequency-locking band where the system oscillates at one half of the forcing frequency are examined. An hexagonal standing-wave pattern and other resonant patterns are observed. The detailed phase diagram of resonance structure in the forcing frequency and forcing amplitude parameter space is calculated. The transitions between the resonant standing-wave patterns are of hysteresis when control parameters are varied, and the presence of multiplicity is demonstrated. Analysis in the framework of amplitude equation reveals that the spatial patterns of the standing waves come out as a result of Turing bifurcation in the amplitude equation.