解斜三角形

本单元的重点：理解和掌握正弦定理和余弦定理；熟记两定理的各种表达形式．     

Lie代数双极化与齐性抗仿凯勒流形的新进展

本文介绍Lie代数双极化与齐性仿凯勒流形的若干新进展,并提出了若干相关问题,指出该领域可能发展的若干方向。     

几何轨道数据与轨道覆盖

为了研究Dixmier对应,Vogan给出了轨道数据与Dixmier代数的概念与抛物诱导方法,同时猜想：轨道数据的抛物诱导与抛物子群的选取无关.讨论了抛物诱导方法的一般性质,在此基础上给出了几何轨道数据抛物诱导的几何解释,最后利用几何方法证明了Vogan上述猜想的重要部分,即：几何轨道数据的抛物诱导与抛物子群的选取无关.     

巴基葱的微观形态与电学特性研究

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用场发射显微镜研究单壁碳纳米管场发射

利用场发射显微镜在小于40×10^-7Pa压强条件下研究了单壁碳纳米管微束在不同温度加热除气后的场发射变化,得出随着除气温度的升高,碳纳米管逸出功经历了从大到小再变大的变化过程.在清洁态(1000℃除气)对应有最小的逸出功,此时场发射图像显示出一定的细致结构.继续升高温度,碳纳米管发生塌缩.     

UNCORRELATED TWO-MODE SU(1,1) COHERENT STATES

We have constructed a new kind of two-mode bosonic realization of SU(1,1) Lie algebra, on the basis of which the SU(1,1) generalized coherent states in the two-mode Fock space are derived. These two-mode SU(1,1) coherent states, which are called uncorrelated two-mode SU(1,1) coherent states, include three special cases. For these states, we study the mean photon number distribution and their non-classical properties, which are photon anti-bunching, violations of Cauchy－Schwarz inequality and two-mode squeezing.     

INVESTIGATION ON THE STRUCTURE AND ELECTRIC PROPERTIES OF BUCKY ONIONS

Bucky onions were fabricated by the DC discharge method and their behaviors and electric properties on Highly Oriented Pyrolytic Graphite (HOPG) were studied by using an atomic force microscope (AFM), a scanning tunneling microscope (STM) and a transmission electron microscope (TEM). Small-sized Bucky onions demonstrated the properties of semiconductors and as the size increased their metallicity became stronger. AFM and STM images revealed the tendency of Bucky onions to form dimers.     

用12C离子模拟质子引起的单粒子效应

在理论分析的基础上 ,提出了一种利用兰州重离子加速器提供的高能12C离子模拟质子引起单粒子效应的途径 .在保证核反应机制是引起单粒子效应主要机制的前提下,用高能12C离子可以模拟质子在功率金属 -氧化物 -半导体场效应晶体管中引起的单粒子烧毁以及单粒子栅极击穿 ,获得质子单粒子效应的饱和截面 ,定性研究质子单粒子效应的角度效应 ,还可以作为高能质子单粒子效应实验前的预备实验 .该方法拓展了兰州重离子加速器加速的轻的重离子在单粒子效应实验研究方面的应用 ,对现阶段国内开展质子单粒子效应实验研究具有重要意义. The mechanisms for proton and heavy ion induced single event effect (SEE) are discussed and a method to simulate proton induced SSEE (PSEE) with high energy 12 C is proposed in this paper. The experiments which can be done by using this method include single event burnout (SEB) and single event gate rupture in power MOSFET, single event upset (SEU) and single event transient (SET) in less sensitive device and angle effect. The experimets with high energy ...     

Reversible,electical and optical switching on silver 3—phenyl—1—ureidonitrile complex thin films

We report on the reversible, electrical and optical switching on silver 3-phenyl-1-ureidonitrile complex thin films. The films can switch from a high impedance state to a low impedance state with an applied electric field at the threshold of 3.5×10⁷V/m. Furthermore, the films can be switched back to the original state by treating the samples at about 80℃. The optical recording is fulfilled using a semiconductor laser with a wavelength of 780 nm. Erasure can be accomplished by bulk heating or by the laser working with the power beneath the threshold. No loss of the organic was found in the experiments. This material may have a potential application in ultrahigh data density storage.     

一类非线性抛物型分布参数控制系统的研究

对一类有广泛应用的活动边界域上非线性抛物型分布参数系统进行建模。采用将系统转化为固定域系统或转化为集中参数系统的方法,从理论上分析了系统的基本特征,得出控制变量存在两个临界值,大者区分边界活动与否,小者区分边界活动后会自动停止与否。将平面、柱面和球面的一维系统表述成统一形式,通过计算机仿真研究了系统开环控制和闭环反馈控制的动态特性,数值结果与理论结果一致。计算机仿真表明系统是适定的、稳定的,而且是可测的和可控的。