Thin-film breakdown counters and their applications (review)

Experimental techniques based on the use of thin-film breakdown counters fabricated at Khlopin Radium Institute are reviewed.     

Diagnosis of phasma in CCD damage process induced by laser

In this paper, the shapes of plasma produced by a Q-switched YAG laser acted repeatedly upon a CCD with MOS structure are used, to investigate the destroying process of the optoelectronic device. The experimental results of CCD destroyed by a 1.06μm laser beam with a pulse width of 15 ns are given.     

Modelling by a planar map: Lyapunov-type numbers in the presence of spiral points

Lyapunov-type numbers are usually defined for diffeomorphisms with a smooth invariant manifold. We consider here the case of a planar diffeomorphism with an invariant curve that contains spiral points. The limits defining the Lyapunov-type numbers are shown to exist. Numerical results for the delayed logistic map illustrate the analysis.     

Synthesis,characterization, and self‐assembly of comb‐dendronized amphiphilic block copolymers

Novel amphiphilic comb‐dendronized diblock copolymers composed of hydrophobic Percec‐type dendronized polystyrene block and hydrophilic comb‐like poly(ethylene oxide) grafted polymethacrylate P(PEOMA) block were designed and synthesized via two steps of atom transfer radical polymerization (ATRP). The comb‐like P(PEOMA) prepared by ATRP of macromonomers (PEOMA) with two different molecular weights (M_n = 300 and 475) were used to initiate the sequent ATRP of dendritic styrene macromonomer (DS). The molecular weights and compositions of the obtained block copolymers were determined by ¹H NMR analysis. The copolymers with relatively narrow polydispersities (1.27–1.38) were thus obtained. The bulk properties of comb‐dendronized block copolymers were studied by using differential scanning calorimetry, polarized optical microscopy and wide‐angle X‐ray diffraction (WAXD). Similar to dendronized homopolymers, the block copolymers exhibited hexagonal columnar liquid‐crystalline phase structure. By using such amphiphilic comb‐dendronized block copolymers as building blocks, the rich self‐assembly morphologies, such as twisted string, vesicle, and large compound micelle (LCM), were obtained in a mixture of CH₃OH and THF. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4205–4217, 2008     

Transitions torichaos through collisions with hyperbolic orbits

Three models of dissipative dynamical systems are described in which a transition from biperiodic to aperiodic motion proceds via collisions of a hyperbolic orbit with either a torus or a strange attractor.     

A linear system solver based on a modified Krylov subspace method for breakdown recovery

Despite its usefulness in solving eigenvalue problems and linear systems of equations, the nonsymmetric Lanczos method is known to suffer from a potential breakdown problem. Previous and recent approaches for handling the Lanczos exact and near-breakdowns include, for example, the look-ahead schemes by Parlett-Taylor-Liu [23], Freund-Gutknecht-Nachtigal [9], and Brezinski-Redivo Zaglia-Sadok [4]; the combined look-ahead and restart scheme by Joubert [18]; and the low-rank modified Lanczos scheme by Huckle [17]. In this paper, we present yet another scheme based on a modified Krylov subspace approach for the solution of nonsymmetric linear systems. When a breakdown occurs, our approach seeks a modified dual Krylov subspace, which is the sum of the original subspace and a new Krylov subspaceK _m (w _j ,A ^T ) wherew _j is a newstart vector (this approach has been studied by Ye [26] for eigenvalue computations). Based on this strategy, we have developed a practical algorithm for linear systems called the MLAN/QM algorithm, which also incorporates the residual quasi-minimization as proposed in [12]. We present a few convergence bounds for the method as well as numerical results to show its effectiveness.Research supported by Natural Sciences and Engineering Research Council of Canada.     

系统故障—灾变及其控制

本文应用灾变理论对实际系统在运行中的故障进行了宏观分析,并在此基础上给出了一般系统在运行期间的故障概率模式。     

中华蚱蜢雄性附腺及储精囊的结构研究

采用光镜观察了中华蚱蜢的雄性附腺和储精囊的显微结构．结果表明，中华蚱蜢的雄性附腺左右对称．各由15根腺管组成，根据分泌物可分为5种类型：透明长腺管a，透明长腺管b，透明短腺管，白色腺管，乳白长腺管；储精囊为细长的管状，左右各一根，和附性腺缠绕在一起．     

Spontaneous translation symmetry breakdown for quantum lattice systems

We study the set of equilibrium states for quantum lattice states in the presence of a translation symmetry of the model. We derive a characterization of the spontaneous breaking of this symmetry, i.e., the decomposition of an invariant equilibrium state into a mixture of noninvariant equilibrium states, in terms of the separability in mean energy of these states for a class of perturbed dynamics.