多层膜结构色滤光片的原理、制备及应用

多层膜结构色滤光片不仅结构简单适合大规模生产,而且所呈现的颜色纯度高、亮度大、不易褪色,因此在光学显示、彩色印刷、美学装饰以及新型光伏等领域有着潜在的应用价值。本文将总结基于多层膜结构设计的彩色滤光片在近年来的研究进展,包括产生不同颜色的两种典型结构及背后的物理机制,多层膜结构色滤光片的制备方法(包括磁控溅射、电子束蒸发、电化学沉积等)以及在彩色太阳能电池、彩色印刷以及新型显示等领域的应用现状,并对多层膜结构色滤光片的发展前景进行展望。     

可调波长半导体激光法布里-珀罗干涉仪

为了对激光十涉仪、高精度位移传感器等测量系统进行纳米级精度的非线性误差校准,需进一步提高中国计量科学研究院与清华大学合作研制的差拍F-P 干涉仪的线性度、稳定性及测量范围.在合理分析空气折射率变化及He-Ne激光器纵模调谐范围等因素对测量的影响基础上,设计并制作了密封干涉光路的真宅系统,并用调谐范围较大的半导体激光器作为工作激光器.实验结果表明,系统在大于1/4波长的行程范围内的线性度有明显的提高,最大非线性误差由8.93 nm减小至1.19 nm.     

带时滞的Laplacian型方程周期解的存在唯一性

利用拓扑度理论和Mawhin's连续定理,研究了一类带有偏差变元的Laplacian型常微分方程的周期解,使用不等式和分析技巧,建立方程解的存在及唯一性条件.有意思的是,与已有文献相比,用来估计先验界的方法是新的,最后,给出了一个实例,验证了所得结论.     

Judging or setting weight steady-state of rational Bézier curves and surfaces

Many works have investigated the problem of reparameterizing rational Bézier curves or surfaces via Mbius transformation to adjust their parametric distribution as well as weights, such that the maximal ratio of weights becomes smallerthat some algebraic and computational properties of the curves or surfaces can be improved in a way. However, it is an indication of veracity and optimization of the reparameterization to do prior to judge whether the maximal ratio of weights reaches minimum, and verify the new weights after Mbius transformation. What's more the users of computer aided design softwares may require some guidelines for designing rational Bézier curves or surfaces with the smallest ratio of weights. In this paper we present the necessary and sufficient conditions that the maximal ratio of weights of the curves or surfaces reaches minimum and also describe it by using weights succinctly and straightway.The weights being satisfied these conditions are called being in the stable state. Applying such conditions, any giving rational Bézier curve or surface can automatically be adjusted to come into the stable state by CAD system, that is, the curve or surface possesses its optimal parametric distribution. Finally, we give some numerical examples for demonstrating our results in important applications of judging the stable state of weights of the curves or surfaces and designing rational Bézier surfaces with compact derivative bounds.     

Liénard方程的比较原理

证明了几个比较原理 ,使方程 x″+f (x) x′+g(x) =0的周期解的存在性与解的有界性定理可以分别用来判定方程 x″+h(x,x′) x′+g(x) =0的周期解的存在性与解的有界性 .     

Reformed Solitary Kinetic Alfven Waves due to Dissipations and Auroral Electron Acceleration

The physical nature of the auroral electron acceleration has been an outstanding problem in space physics for decades. Some recent observations from the auroral orbit satellites, FREJA and FAST, showed that large amplitude solitary kinetic Alfvén waves (SKAWs) are a common electromagnetic active phenomenon in the auroral magnetosphere. In a low-β (i.e., β/2<<m_e/m_i<<1) plasma, the drift velocity of electrons relative to ions within SKAWs is much larger than thermal velocities of both electrons and ions. This leads to instabilities and causes dissipations of SKAWs. In the present work, based on the analogy of classical particle motion in a potential well, it is shown that a shock-like structure can be formed from SKAWs if dissipation effects are included. The reformed SKAWs with a shock-like structure have a local density jump and a net field-aligned electric potential drop of order of m_ev_A²/e over a characteristic width of several λ_e. As a consequence, the reformed SKAWs can efficiently accelerate electrons field-aligned to the order of the local Alfvén velocity. In particular, we argue that this electron acceleration mechanism by reformed SKAWs can play an important role in the auroral electron acceleration problem. The result shows that not only the location of acceleration regions predicted by this model is well consistent with the observed auroral electron acceleration region of 1—2 R_E above the auroral ionosphere, but also the accelerated electrons from this region can obtain an energy of several keV and carry a field-aligned current of several μA/m² which are comparable to the observations of auroral electrons.     

Generalized Canonical Noether Theorem and Poincare—Cartan Integral Invariant ofr a System with a Singular High—Order Lagrangian and an Application

Based on the canonical action,a generalized canonical first Noether theorem and Poicare-Cartan integralinvariant for a system with a singular high-order Lagrangian are derived.It is worth while to point out that the constraints are invariant under the total variation of canonical variables including time.We can also deduce the result,which differs from the previous work to reuire that the constraints are invariant under the simultaneous variations of canonical variables.A counter example to a conjecture of the Dirac for a system with a singular high-order Lagrangian is given,in which there is no linearization of constraint.     

三角域上带两个形状参数的Bézier曲面的扩展

给出了三角域上带双参数λ1,λ2的类三次Bernstein基函数,它是三角域上三次Bernstein基函数的扩展.分析了该组基的性质并定义了三角域上带有两个形状参数λ1,λ2的类三次Bernstein-Bézier(B-B)参数曲面.该基函数及参数曲面分别具有与三次Bernstein基函数及三次B-B参数曲面类似的性质.当λ1,λ2取特殊的值时,可分别得到三次Bernstein基函数及三次B-B参数曲面以及参考文献中所定义的类三次Bernstein基函数及类三次B-B参数曲面.由实例可知,通过改变形状参数的取值,可以调整曲面的形状.     

NORM SUMMABILITY OF N(O)RLUND LOGARITHMIC MEANS ON UNBOUNDED VILENKIN GROUPS

The (N(o)rlund)logarithmic means of the Fburier series is:tnf=1/ln∑n-1k=1Skf/n-k,where ln=∑n-1k=11/k.In general,the Fejér(C,1)means have better propeaies than the logarithmic ones.We compare them and show that in the case of some unbounded Vilenkin systems the situation changes.     

Gel’fand三元组上由同一Lévy过程定义的不同分数Lévy过程之间的积分变换公式(英文)

本文利用Riemann-Liouville分数积分算子的半群性质以及分数Lévy过程的Wie-ner积分,给出由同一平方可积Lévy过程定义的不同分数Lévy过程之间的积分变换公式.