超导技术在飞轮储能系统中的应用及前景

阐述了飞轮储能装置原理和超导磁悬浮理论,并设计了超导飞轮储能系统的基本结构。采用超导磁悬浮轴承技术可以解决普通的飞轮储能系统由于有机械轴承摩擦产生的能量损耗,克服普通飞轮储能的低效、储能时间短等问题。最后简要介绍了超导飞轮储能技术的发展前景。     

Thermoelastic solutions for thermal distributions moving over thin slim rod under memory-dependent three-phase lag magneto-thermoelasticity

Abstract

Enlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena due to the influence of magnetic field and moving heat source in a rod in the context of three-phase lag (TPL) theory of thermoelasticity. Both ends of the rod are fixed and heat insulated. Employing Laplace transform as a tool, the problem has been transformed into the space-domain and solved analytically. Finally, solutions in the real-time domain are obtained by applying the inverse Laplace transform. Numerical calculation for stress, displacement, and temperature within the rod is carried out and displayed graphically. The effect of moving heat source speed on temperature, stress, and temperature is studied. It is found from the distributions that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed. For the better understanding of the effect of moving heat source on all the distributions, three animations are added.     

Change in motor cortex activation for muscle release by motor learning

For central nervous system disorders'' rehabilitation, it is important to accurately understand motor control and implement an appropriate motor learning process to induce neuroplastic changes. The neurophysiological studies have revealed that neural control mechanisms are crucial during both the onset of muscular activities and muscle release after contraction. When performing various movements during daily activities, muscle relaxation control enables precise force output and timing control. Moreover, surround inhibition is a functional mechanism in the motor system. Surround inhibition of the motor system may be involved in the selective execution of desired movements. This review demonstrates cortical excitability resulting from motor learning, movement control mechanisms including muscle relaxation and the suppression of nontarget muscle groups, and the voluntary drive''s importance that is required for movement.     

Mechanistic Insights into C(sp2)−C(sp)N Reductive Elimination from Gold(III) Cyanide Complexes

A new family of phosphine-ligated dicyanoarylgold(III) complexes has been prepared and their reactivity towards reductive elimination has been studied in detail. Both, a highly positive entropy of activation and a primary ^12/13C KIE suggest a late concerted transition state while Hammett analysis and DFT calculations indicate that the process is asynchronous. As a result, a distinct mechanism involving an asynchronous concerted reductive elimination for the overall C(sp²)−C(sp)N bond forming reaction is characterized herein, for the first time, complementing previous studies reported for C(sp³)−C(sp³), C(sp²)−C(sp²), and C(sp³)−C(sp²) bond formation processes taking place on gold(III) species.     

Modeling liquid-liquid interface level in a horizontal three-phase separator with a bucket and weir

The flow behavior in a three-phase separator with a bucket and weir was analyzed, and a theoretical equation for calculating the liquid-liquid interface level (H_H) in gravity separation zone was derived. The analysis indicates that the H_H increases as the flow rate and the density ratio of heavy to light liquid increase, and decreases linearly with increasing height difference between heavy and light liquid overflow weirs. The calculated H_H under different operating conditions is in good agreement with the experimental. With the proposed equation, the thicknesses of heavy and light liquid layers can be calculated, and then the minimum lengths of two phase layers required for separation can be determined separately. From the minimum lengths it can be clearly indicated that the governing step of liquid-liquid separation is in heavy or light liquid layers, hence the sizing of the separator can be optimized.     

含BN旋转轴的光驱动分子马达的理论设计和机理研究

依据B=N键与C=C键的电子结构相似性,以Feringa型二苯乙烯型光驱动分子马达（CC-stilbene）为母体,设计了含极性旋转轴的模型马达BN-stilbene.CASPT2//CASSCF计算结果表明,优化所得的BN-stilbene分子的基态存在四个与CC-stilbene马达结构相似、相对能量一致的螺旋异构体;B=N极性共价双键对BN-stilbene的基态和激发态电子结构有显著影响.对BN-stilbene模型马达的工作机理研究表明,极性旋转轴的引入使得BN-stilbene中S₁/S₀-CI与激发态中间体构型更加相似且能量更低,同时可增加旋转的驱动力,起到改进分子马达光异构化过程的单向性的目的.     

Dynamical behaviors of the chaotic Brushless DC motors model

This article is concerned with the boundedness solutions of the brushless DC motor system. For this system, the global attractive set and positively invariant set are obtained based on generalized Lyapunov function stability theory and the extremum principle of function. Furthermore, the rate of the trajectories is also obtained. Numerical simulations are presented to show the effectiveness of the proposed scheme. © 2014 Wiley Periodicals, Inc. Complexity 21: 79–85, 2016     

Asynchronous cellular automata and pattern classification

This article designs an efficient two‐class pattern classifier utilizing asynchronous cellular automata (ACAs). The two‐state three‐neighborhood one‐dimensional ACAs that converge to fixed points from arbitrary seeds are used here for pattern classification. To design the classifier, (1) we first identify a set of ACAs that always converge to fixed points from any seeds, (2) each ACA should have at least two but not huge number of fixed point attractors, and (3) the convergence time of these ACAs are not to be exponential. To address the second issue, we propose a graph, coined as fixed point graph of an ACA that facilitates in counting the fixed points. We further perform an experimental study to estimate the convergence time of ACAs, and find there are some convergent ACAs which demand exponential convergence time. Finally, we identify there are 73 (out of 256) ACAs which can be effective candidates as pattern classifier. We use each of the candidate ACAs on some standard datasets, and observe the effectiveness of each ACAs as pattern classifier. It is observed that the proposed classifier is very competitive and performs reliably better than many standard existing classifier algorithms. © 2016 Wiley Periodicals, Inc. Complexity 21: 370–386, 2016     

Monitoring ssDNA Binding to the DnaB Helicase from Helicobacter pylori by Solid‐State NMR Spectroscopy

DnaB helicases are bacterial, ATP‐driven enzymes that unwind double‐stranded DNA during DNA replication. Herein, we study the sequential binding of the “non‐hydrolysable” ATP analogue AMP‐PNP and of single‐stranded (ss) DNA to the dodecameric DnaB helicase from Helicobacter pylori using solid‐state NMR. Phosphorus cross‐polarization experiments monitor the binding of AMP‐PNP and DNA to the helicase. ¹³C chemical‐shift perturbations (CSPs) are used to detect conformational changes in the protein upon binding. The helicase switches upon AMP‐PNP addition into a conformation apt for ssDNA binding, and AMP‐PNP is hydrolyzed and released upon binding of ssDNA. Our study sheds light on the conformational changes which are triggered by the interaction with AMP‐PNP and are needed for ssDNA binding of H. pylori DnaB in vitro. They also demonstrate the level of detail solid‐state NMR can provide for the characterization of protein–DNA interactions and the interplay with ATP or its analogues.     

多模态控制在步进电机位置伺服系统中的应用研究

针对步进电机伺服系统的响应速度慢、稳态误差低的问题,提出了一种多模态控制策略。根据误差大小调节两种控制策略对被控对象的作用权值,使最终的控制量连续输出,实现控制策略无扰动、平滑的切换。半实物仿真实验结果表明,该控制策略较好地综合了模糊控制和模糊PID控制的优势,系统反应速度快,震荡小,抗干扰能力强,同时一定程度上改善了低频振荡和高频失步的问题,具有实际应用价值。