Discrete Green's Function for Lattice Random Walk

A lattice random walk model based on particles scattering on discrete lattice of homogenous space is introduced. The discrete Green's function (DFG) for two-dimensional and three-dimensional lattice random walk of photon is found and proved by mathematical induction. The convolution theorem of photon lattice random walk is presented. They can be used with the method of images to calculate the photon density distribution in semi-infinite and finite slab homogenous turbid media such as tissue.     

荧光材料Y_2O_3:Eu变温拉曼光谱分析

本文用显微拉曼谱仪在波长为785 nm的激光激发下,对Y2O3:Eu陶瓷在温度83-473 K间进行了系统的变温拉曼实验研究。实验发现Y2O3:Eu的一些振动模在低温下没有出现,只有当温度达到一定值之后才可以被观察到,分析表明这是由于温度变化引起的简并振动模式分裂。此外,Y2O3:Eu的拉曼峰位、半高全峰宽(FWHM)也是温度的非线性函数,且不同的拉曼峰遵循不同的函数关系,本文分析这是由于晶格的各向异性导致的。     

Information Entropy Squeezing for a Atom in Mode-Mode Competition System

The entropy squeezing properties for a two-level atom interacting with a two-mode field via two different competing transitions are investigated from a quantum information point of view. The influences of the initial state of the system and the relative coupling strength between the atom and the field on the atomic information entropy squeezing are discussed. Our results show that the squeezed direction and the frequency of the information entropy squeezing can be controlled by choosing the phase of the atom dipole and the relative competing strength of atom-field, respectively. We find that, under the same condition, no atomic variance squeezing is predicted from the HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information entropy is a remarkable precision measure for the atomic squeezing in the considered system.     

Four-Component Borocarbonylation of Vinylarenes Enabled by Cooperative Cu/Pd Catalysis: Access to β-Boryl Ketones and β-Boryl Vinyl Esters

We report here a general four-component synthetic procedure for the preparation of β-boryl ketones and β-boryl vinyl esters. Joint catalyzed by palladium and copper catalysts, borocarbonylative reaction between vinylarenes, aryl halides/triflates, B₂Pin₂, and carbon monoxide proceed successfully. A variety of synthetically useful β-boryl ketones were synthesized in good to high yields by using aryl iodides as the substrates. It is noteworthy that when aryl triflates were applied as the starting materials, β-boryl vinyl esters were synthesized in a similar manner and with broad functional group tolerance. A rational mechanism for this reaction was also proposed.     

散斑条纹的快速高精度处理技术

本文提出一种快速高精度散斑杨氏条纹(斑纹)场处理方法——同态阀值滤波法。用它实现了散斑场条纹的快速、逐点连续高精度处理。     

关于光激射器的线宽

本文从描述光激射器工作的基本方程出发,讨论了光激射器光束线宽的“短期”(short-time)部分。通常都以下式描写这部分线宽:△v_s=(8πhv(△v′)²)/P,(1)其中△v′是谐振腔电磁模的半宽度;v为光束频率;P为输出功率。我们的主要结论可以归结为以下三点:(1)线宽主要是由与电磁模耦合的耗散体系引起的,与分子耦合的耗散体系的贡献是可以忽略的;(2)在单模近似下,只要分子的线宽比电磁模的线宽大得多,则(1)式是正确的;(3)如果多模谐振腔中激发模与其他模之间的相互作用是强的,则式(1)将被推广为 △v_s=(8πhv(△v′)²)/P+(4hv(△v′))/P somefromn=(λ′≠λ)(r_λλ′²/(rλ′),(2) 其中r_λλ′是相关弛豫系数;r_λ′是模λ′的线宽。在某些情况下,式(2)中第二项可以比其第一项还大。所以,这可能是目前关于线宽的实验结果与由式(1)计算结果不相符合的原因之一。     

Hamiltonian[k,k+1]-因子

本文考虑n/2-临界图中Hamiltonian[k,k+1]-因子的存在性。Hamiltonian[k,k+1]-因子是指包含Hamiltonian圈的[k,k+1]-因子;给定阶数为n的简单图G,若δ(G)≥n/2而δ(G\e)相似文献   

C*-代数交叉积上的渐近同态(英文)

林华新和松井宏树提出了可分C~*-代数上的渐近同态的概念,以及Cantor极小系统上弱逼近共轭的概念.设A为Ko群有限生成的AF代数,α,β为A上的具有Rokhlin性质的*-自同构.则α和β弱逼近共轭的充要条件是,存在两列渐近同态{φ_n}:A_α→A_β和{ψ_n}:A_β→A_α,以及两列*-自同构{Φ_n},{Ψ_n}:A→A,满足对任意的a∈A,均有lim_(n→∞)‖φ_noj_α(a)-jβoΦ_n(a)‖=0和lim_(n→∞)‖ψ_nojβ(a)-jα·Ψ_n(a)‖=0.     

Identification of a 9/2-[505] isomer in the neutron-rich 193Os nucleus

The neutron rich nucleus ¹⁹³Os was produced in the ¹⁹²Os(⁷Li, ⁶Li)¹⁹³Os reaction. An isomeric state based on the 9/2^-[505] Nilsson orbital was identified in the present work. The half-life of the isomeric state was extracted and discussed in terms of the K quantum number. A level scheme built on the isomeric state was proposed based on the experimental data.     

二元凸函数的判别条件

给出了二元凸函数的定义,导出了二元凸函数的判别条件,该判别条件由二元函数的二阶导数给出.用二元凸函数的判别条件和半正定的(半负定)矩阵的性质,得到了二元二次多项式凸性的简单判别形式.