虚级联在数字包封技术中的应用

介绍了光传送网数字包封技术中虚级联概念、所用的虚级联容器，详细分析了常用的客户信号的虚级联映射方法。     

环形斑光束在非线性克尔介质中的自聚焦效应

通过数值求解非线性Schrödinger方程,详细讨论了环形斑光束在非线性克尔介质中的传输特性.当入射光超过一定的功率时,光束产生多级自聚焦现象,自聚焦焦点出现在离轴的环上;自聚焦阈值与环形光束的半径有关;传输过程中光斑存在横向分裂现象,并且分裂与聚焦交替进行;当两个半径不同的同轴环状光束同时在非线性介质中传输时产生耦合效应,耦合效应使其自聚焦增强.     

Elliptic boundary value problems in hybrid domains

We derive asymptotic transmission conditions at points where segments are attached to a three-dimensional body. These conditions result in a formally self-adjoint problem on a hybrid set with properties similar to those of standard boundary value problems. In particular, the problem has a zero index and possesses a variational statement. If the systems of differential equations have a special form, then the operator of the problem is realized as a self-adjoint extension of the decoupled operators of the problems on the body and the segments. From this viewpoint, we interpret the results of asymptotic analysis of coupled thin and solid bodies.Dedicated to Victor Borisovich Lidskii on the occasion of his jubileeTranslated from Funktsionalnyi Analiz i Ego Prilozheniya, Vol. 38, No. 4, pp. 55–72, 2004Original Russian Text Copyright © by S. A. NazarovSupported by the Russian Foundation for Basic Research (grant No. 00-01-00835).     

Reflection and Transmission Times Through a Linear Potential

Reflection and transmission times through a linear potential is studied by using the stationary phase method. The incident particle is described by a wave packet constructed from a momentum distribution (k – k) highly concentrated around a fixed value k. The way the reflection and transmission times are calculated is similar to the way the phase time is defined for a rectangular potential.     

Powder Neutron Diffraction and TEM Investigations of Bi0.775Ln0.225O1.5 Oxide Conductors (Ln=La, Pr, Nd, Sm, Tb, Dy) with Rhombohedral Bi-Sr-O type: Structural Relationships with Monoclinic ε-Bi4.86La1.14O9 Form

Structural investigations of Bi_0.775Ln_0.225O_1.5 phases with rhombohedral Bi-Sr-O type, have been carried out using complementary techniques. Average crystal structures were refined from neutron diffraction powder data using the Rietveld method for Ln=La, Pr, Nd and Tb. The comparison with the monoclinic Bi_4.86La_1.14O₉ structure previously determined using the same technique has been done. For both types of structure, a piling of slabs constituted of a (Bi₍₁₎, Ln) oxide layer, inserted between two Bi₍₂₎ oxide layers, is observed. In the rhombohedral phases there are moreover oxide ions in the inter-slab spaces responsible for the well-known conductivity of these phases, while in the monoclinic Bi_4.86La_1.14O₉ structure, the absence of oxygen in the inter-slab spaces, is compensated with the presence of the Bi₍₂₎ lone pair electrons localized at a significant distance (≅1.20 Å), which participate in the cohesion of the crystal structure. TEM study of Bi_0.775Ln_0.225O_1.5 samples, has confirmed the existence of superstructures for these phases and has allowed to propose two types (respectively for La and for Nd, Sm, Tb or Dy) of q₁^* and q₂^* modulation wave vectors.     

Spectral Properties of Single Crystals of Synthetic Diamond

The half-width of the spectrum of Raman scattering (RS) of the first order of a diamond single crystal grown in a nickel-free system containing nitrogen getters is identical to all growth sectors (1.69 ± 0.02 cm^–1). The sectorial inhomogeneity is not reflected in the transmission spectra and birefringence of this crystal. The nitrogen concentration is 4·10¹⁷ cm^–3. For different growth sectors of the diamond crystal grown in the Ni–Fe–C system, the half-width of the Raman line varies from 1.74 to 2.08 cm^–1, differences in the transmission spectra and birefringence are observed, and photoluminescence is revealed. The concentration of nitrogen in the growth sectors {001} is 1.6·10¹⁹ cm^–3, the content of nickel is estimated to be at a level of 10¹⁹ cm^–3, and the content of nitrogen in the {¯111} sectors is 4·10¹⁹ cm^–3.     

Effects of Line Parameters on Soliton-Like Propagation in Nonlinear Transmission Lines: Application to the Optimization of Frequency Triplers

In this paper, soliton propagation in nonlinear transmission lines (NLTLs) periodically loaded with heterostructure barrier varactors is studied. From the lumped element equivalent circuit of the line we have analyzed the influence of transmission line parameters (i.e, per-section inductance and capacitance) on soliton propagation characteristics. It is shown that by increasing these parameters, a faster separation of input signals into solitons is achieved. From the point of view of NLTL harmonic generation, this gives additional flexibility to optimize multiplier performance by appropriate circuit design. These conclusions are supported from the analysis of a frequency tripler, where device losses are included.     

准完全带隙胶体非晶光子晶体

三维面心立方结构的固有的高对称性使其只具备非完全光子带隙,而非晶结构可降低对称性导致准完全光子带隙的出现.实验结果表明非晶胶状晶体具有准完全光子带隙.非晶胶状光子晶体中的光子带隙的禁带宽度与波长均不随光入射到样品池的角度的变化而明显变化.其禁带宽度比SiO₂小球面心单晶的禁带宽度宽得多 关键词： 光子带隙 非晶 光谱     

光纤制导双向传输系统

光纤制导战术导弹是一种精确制导武器,它主要用于远距离打击敌方的高价值目标,光纤制导战术导弹具有射程远,抗电磁干扰,隐蔽发射,图像制导等一系列优点,因而受到军方的高度重视并得到迅速的发展,光纤双向传输系统是光纤制导导弹系统中一个重要标志性的组成部分。本文详细地介绍弛光纤制导双向传输系统的特点,构成及工作原理。     

Synthesis and Structure of Magnetic Core-shell Ni–Ce Nanocomposite Particles

A new type of magnetic core-shell Ni–Ce nanocomposite particles (15–50 nm) is presented. SEM observations suggest the particles are strongly ferromagnetic, interacting with ordered chain-like features. Typical HR-TEM images demonstrate that many planar defects (nanotwins and stacking faults) exist in the surface shell and large Ni core zone (10–40 nm) of the particles; the inner shell layers (4–6 nm) consist of NiCe alloy and the outermost shell is NiO. Nano-diffraction patterns show an indication of well-defined spots characteristic of nanocomposite materials, of which certain crystal facet orientation relationships between orthorhombic [111] of NiCe and cubic [311] of Ni₂Ce, face-center crystal [222] of NiO, cubic [111] of nickel have been identified. This confirms the nature of this core-shell nanocomposite particle.