SOME GEOMETRIC PROPERTIES OF A NEW DIFFERENCE SEQUENCE SPACE INVOLVING LACUNARY SEQUENCES

In this paper, we define a new generalized difference sequence space involving lacunary sequence. Then, we examine k-NUC property and property （β） for this space and also show that it is not rotund where p = （pr） is a bounded sequence of positive real numbers with pr ≥ 1 for all r ∈ N.     

Use of a fluorine-containing solvent in the synthesis of YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7 − δ</Subscript> single crystals

A laboratory technological procedure has been developed for the synthesis of high-temperature superconducting YBa₂Cu₃O_{7 ? δ} single crystals (T _c ～ 90 K, ΔT _c ～ 1.0 K) up to 0.25 cm² in size from a nonstoichiometric fluorine-containing flux of (YO_1.5)(BaO)_{4 ? x}(BaF₂)_x(CuO)₁₀, where 2 ≥ x ≥ 0, using a combination of enhanced nucleation and directional crystallization by the Czochralski method. Studies using differential thermal analysis demonstrated that the addition of BaF₂ decreased the eutectic-crystallization temperature and increased the crystal-growth rate. The optimum concentration of BaF₂ in the starting melt composition was found (x = 0.2). The single-crystal surface was studied by atomic-force nanoscopy. The morphology of single crystals that have been synthesized from a melt of their own components differs substantially from that of crystals grown from a BaF₂-containing melt.     

Analysis of multiserver retrial queueing system: A martingale approach and an algorithm of solution

The paper studies a multiserver retrial queueing system withm servers. Arrival process is a point process with strictly stationary and ergodic increments. A customer arriving to the system occupies one of the free servers. If upon arrival all servers are busy, then the customer goes to the secondary queue, orbit, and after some random time retries more and more to occupy a server. A service time of each customer is exponentially distributed random variable with parameter μ₁. A time between retrials is exponentially distributed with parameter μ₂ for each customer. Using a martingale approach the paper provides an analysis of this system. The paper establishes the stability condition and studies a behavior of the limiting queue-length distributions as μ₂ increases to infinity. As μ₂→∞, the paper also proves the convergence of appropriate queue-length distributions to those of the associated “usual” multiserver queueing system without retrials. An algorithm for numerical solution of the equations, associated with the limiting queue-length distribution of retrial systems, is provided. AMS 2000 Subject classifications: 60K25 60H30.     

Characteristics of a localized gas discharge

The rf capacitive gas discharge with an interelectrode distance of 15–200 µm is studied, and possible forms of its existence are established. The conditions for the formation of discrete microdischarges with a preset geometry, which are localized near some elements of the surfaces of the electrodes, are formulated.     

Side effects in electrolytic deposition of nickel–boron coatings

Russian Journal of Applied Chemistry - Some side effects arising in the course of electrolytic deposition of nickel–boron coatings in the presence of sodium decahydrodecaborate were revealed....     

一种分析自由电子激光场的新量子方法

将固体理论中的LLP变换用于研究自由电子激光场的量了态,并求得了小信号增益,这种新方法简捷且有助于深入地探讨自由电子激光场的量子特性. 关键词：     

蛙峡核的视野区域对应投射和双眼反应

本文用玻璃微电极从黑斑蛙(Rana nigromaculata)左峡核细胞外记录了125个单位的视觉反应,并用钴染色法标记出101个电极尖端位置,以便重建峡核内的视野图。在所记录的单位中,80％对静止光点显示给光(ON)-撤光(OFF)反应,许多单位对通过其感受域的黑、白目标的运动有方向选择性。所有钴标记点都在核内,表明峡核本身是蛙视觉系统的一个局限部分。在峡核内有一个视野投射圈。整个对侧半视野和同侧半视野的鼻侧40°呈区域对应地投射到峡核上。核内的无细胞带是对侧半视野与同侧半视野的分界线,它的背侧是对侧视野代表区。上视野投射到核的嘴半部、尾半部的中央和内腹部分。下视野的代表在尾半部的背部和外侧部。在峡核里观察到15个双眼单位,其中13个主要被对侧眼兴奋,2个几乎同等地被两只单眼兴奋。标记成功的14个双眼单位主要位于峡核嘴半部的髓质内。