Thin-Film Nonlinear Optical Crystals for Intracavity Electro-Optic Modulation

Optics and Spectroscopy - Methods of preparation of single-crystal 4-N,N-dimethylamino-4′-N′-methyl stilbazolium tosylate (DAST) films with a thickness of several micrometers, designed...     

Temperature–Frequency Dependence of the Dielectric Response in LuFe2O4 Multiferroics

Physics of the Solid State - The temperature–frequency spectra of the complex dielectric permittivity of the LuFe2O4 multiferroics have been studied in the temperature range 100–400 K...     

A Study of the Protective Properties of a Combined Cermet Material upon a High-Speed Impact

Technical Physics - The ballistic resistance of a combined cermet material based on a high-hardness ceramic bound with an intermetallide on a high-strength metal substrate, (TiB2 + NiTi) + Ti, is...     

The Application Potential of Silicon Photomultipliers for a Camera of a Small-Size Cherenkov Gamma-Ray Telescope for Reducing the Detection Threshold

Technical Physics - Source and noise signals in a new camera of the TAIGA-IACT Cherenkov γ-ray telescope based on silicon photomultipliers (SiPM) have been simulated. It is shown that...     

Formation of the Heavy Isotope $${}^{\boldsymbol{6}}$$ He upon Stopped Pion Absorption by Nuclei

Physics of Atomic Nuclei - A survey of experimental results on the level structure in the heavy helium isotope $${}^{6}$$ He that were obtained in reactions induced by stopped pion absorption in...     

Dynamic Destruction as Analogs of Critical Phenomena in Metal Samples with Various Geometries within a Wide Ranges of Amplitude–Time Characteristics of External Action

Physics of Atomic Nuclei - The quantitative characteristics of the products of dispersion and the cascade of dissipative structures arising in metals under shock-wave loading are determined. The...     

Test Beams of the LPI Accelerating Complex Pakhra

Physics of Atomic Nuclei - In this paper, we report the characteristics of the generated beams, the extracted electron beam and the beam of secondary electrons/positrons, of the LPI accelerator...     

BEPCII直线加速器数字延时触发器的设计与实现

针对北京正负电子对撞机II期（BEPC II）直线加速器升级改造过程中束流位置探测器（BPM）电子学对外部触发信号的需求,设计了一台高精度延时控制、上升时间短和参数灵活调节的数字延时触发器。采用FPGA（现场可编程门阵列）作为主控制器展开设计,重点介绍了基于FPGA的边沿检测模块和多通道延时处理模块的设计与仿真,描述了FPGA和驱动电路的设计方案以及在直线加速器上的应用。经测试,延时可调范围4 ns～4 μs,最小步进4 ns,步进误差0.125%;上升时间2 ns,延时抖动135.4 ps。     

Magnetorefractive effect in La<Subscript>0.7</Subscript>Ca<Subscript>0.3</Subscript>MnO<Subscript>3</Subscript> in the infrared spectral range

The reflection and magnetic reflection spectra, magnetic resistance, electrical properties, and equatorial Kerr effect in La_0.7Ca_0.3MnO₃ crystals have been complexly investigated. The measurements have been performed in wide temperature and spectral ranges in magnetic fields up to 3.5 kOe. It has been found that magnetic reflection is a high-frequency response in the infrared spectral range to the colossal magnetore-sistance near the Curie temperature. Correlation between the field and temperature dependences of the magnetic reflection and colossal magnetoresistance has been revealed. The previously developed theory of the magnetorefractive effect for metallic systems makes it possible to explain the experimental data at the qualitative level. Both demerits of the theory of the magnetorefractive effect in application to the magnets and possible additional mechanisms responsible for the magnetic reflection are discussed.     

Zeros of the Jones Polynomial for Multiple Crossing-Twisted Links

Let D be a general connected reduced alternating link diagram, C be the set of crossings of D and C′ be the nonempty subset of C. In this paper we first define a multiple crossing-twisted link family {D ⁿ (C′)|n=1,2,…} based on D and C′, which produces (2,2n+1)-torus knot family, the link family A _n defined in Chang and Shrock (Physica A 301:196–218, 2001) and the pretzel link family P(n,n,n) as special cases. Then by applying Beraha-Kahane-Weiss’s Theorem we prove that limits of zeros of Jones polynomials of {D ⁿ (C′)|n=1,2,…} are the unit circle |z|=1 (It is independent of the selections of D and C′) and several isolated limits, which can be determined by computing flow polynomials of subgraphs of G corresponding to D. Furthermore, we use the method of Brown and Hickman (Discrete Math. 242:17–30, 2002) to prove that, for any ε>0, all zeros of Jones polynomial of the link D ⁿ (C) lie inside the circle |z|=1+ε, provided that n is large enough. Our results extend results of F.Y. Wu, J. Wang, S.-C. Chang, R. Shrock and the present authors and refine partial result of A. Champanerkar and L. Kofman.