Experimental investigation of a seven-element hexagonal fiber coherent array

The phase noises of a 10-m polarization-maintaining （PM） fiber and a 10-W PM fiber amplifier are experimentally measured. The results indicate that the 10-m PM fiber with similar phase noise could be used to investigate the architecture of master oscillator power amplifier coherent combination. A seven-element hexagonal fiber coherent array is developed to investigate the far-field distribution and phase controlling technique of a coherently combining fiber laser array. A hexagonal prism is designed as the combining and splitting component to achieve a fill factor of 0.66. The hill climbing method is employed to detect and lock the element phase.     

Nd∶Y_3Al_5O_(12)单晶及纳米粉体的Raman光谱分析

测量了YAG（Y3Al5O12）/Nd∶YAG单晶、Nd∶YAG前驱物及其在不同温度下煅烧获得粉体的拉曼光谱,对谱峰的振动模式进行了指认,对结果进行了分析。Nd∶YAG前驱物在煅烧时,有一个由非晶态向晶态的转化过程;700℃下烧结前驱物获得非晶态产物的结构中含有AlO4四面体结构;随着煅烧温度的升高,拉曼光谱的变化主要表现在两个方面：一是谱峰半高宽（FWHM）减小,谱峰强度增大;二是一些拉曼光谱谱峰发生了频移,这是纳米多晶粉体的界面组元的有序度提高所致。另外,800℃下煅烧获得的Nd∶YAG纳米粉体的晶格振动模式与Nd∶YAG晶体的晶格振动模式存在差异,这是纳米多晶粉体的界面组元的贡献所致。     

A simplified basis for Bell–Kochen–Specker theorems

We show that a reduced form of the structural requirements for deterministic hidden variables used in Bell–Kochen–Specker theorems is already sufficient for the no-go results. Those requirements are captured by the following principle: an observable takes a spectral value x if and only if the spectral projector associated with x takes the value 1. We show that the “only if” part of this condition suffices. The proof identifies an important structural feature behind the no-go results; namely, if at least one projector is assigned the value 1 in any resolution of the identity, then at most one is.     

Quantum Quenches with Random Matrix Hamiltonians and Disordered Potentials

We numerically investigate statistical ensembles for the occupations of eigenstates of an isolated quantum system emerging as a result of quantum quenches. The systems investigated are sparse random matrix Hamiltonians and disordered lattices. In the former case, the quench consists of sudden switching‐on the off‐diagonal elements of the Hamiltonian. In the latter case, it is sudden switching‐on of the hopping between adjacent lattice sites. The quench‐induced ensembles are compared with the so‐called “quantum micro‐canonical” (QMC) ensemble describing quantum superpositions with fixed energy expectation values. Our main finding is that quantum quenches with sparse random matrices having one special diagonal element lead to the condensation phenomenon predicted for the QMC ensemble. Away from the QMC condensation regime, the overall agreement with the QMC predictions is only qualitative for both random matrices and disordered lattices but with some cases of a very good quantitative agreement. In the case of disordered lattices, the QMC ensemble can be used to estimate the probability of finding a particle in a localized or delocalized eigenstate.     

时域分析自适应光学中的非等晕性

本文利用时域分析方法讨论了自适应光学中的非等晕性以及相位梯度法克服非等晕性的适用性,并将位相补偿和位相梯度法补偿情况下的剩余位相结构函数和Strehl比的一般表达式,统一用传递函数H(f)来描述。该关系式不仅可分析非等晕性,同时可讨论大气平均风场和系统响应带宽对自适应光学系统补偿效率的影响。     

Effects of Anions and Cations on π-Complexation Between Olefin and Metal Halide

Introduction Separation,recoveryofolefinorremovalof tracequantitiesofolefinfromitsmixturesbyusing π-complexatonisamostpromisingsolution,com- paredwithenergy-intensivedistillationorotheral- ternatives.π-Complexationisasubgroupofchemi- calcomplexationwhereamixtureisbroughtinto contactwithasecondphasecontainingacomplex- ingagent[1].Forexample,theadsorbentscontain- ingAg+orCu+canselectivelyadsorbolefinfroman ethylene/ethaneorpropylene/propanemixture. Becausetheπ-complexationbondsarestronger th…     

基于信息理论的采样成像系统匹配设计

把信息论应用于采样成像系统中，用互信息量评价图像捕捉部分的性能，做出基于信息论的系统评价仿真曲线，提出基于信息论的系统优化设计的指标。根据仿真结果，给出光学成像系统与CCD阵列探测器的宏观匹配特性与最佳匹配条件。图像捕捉实验结果证明了理论分析和仿真结论的正确性。     

Thermal Behavior of the Fluorescence Lines of Ho~(3 ) in Cr,Tm,Ho∶YAG

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｃｒ,Ｔｍ ,Ｈｏ∶ＹＡＧｉｓａｋｉｎｄｏｆｖｅｒｙｉｍｐｏｒｔａｎｔ 2 μｍｌａｓｅｒｃｒｙｓｔａｌ,ｗｈｏｓｅ 2 .1 μｍｌａｓｅｒｉｓａｂｓｏｒｂｅｄｓｔｒｏｎｇｌｙｂｙｗａｔｅｒｃｏｍｐｏｎｅｎｔｏｆｔｉｓｓｕｅ,ｒｅｓｕｌｔｉｎｇｉｎｓｈａｌｌｏｗｔｉｓｓｕｅｐｅｎｅｔｒａｔｉｏｎａｎｄｇｏｏｄｓｕｒｇｉｃａｌｐｒｅｃｉｓｉｏｎｉｎｍｏｓｔｔｙｐｅｓｏｆｓｏｆｔａｎｄｈａｒｄｔｉｓｓｕｅ .Ｈｏ∶ＹＡＧｌａｓｅｒｈａｓｂｅｃｏｍｅａｎｉｍｐｏｒｔａｎｔｓｏｕｒｃｅ…     

On the Generalized Hurwitz Equation and the Baragar–Umeda Equation

We consider the generalized Hurwitz equation \({a_1x_1^2 + \cdots + a_nx_n^2 = dx_1 \cdots x_n - k}\) and the Baragar–Umeda equation \({ax^2 + by^2 + cz^2 = dxyz + e}\) for solvability in integers.