Magnetizing of permanent magnets using HTS bulk magnets

A demagnetized Nd–Fe–B permanent magnet was scanned just above the magnetic pole which contains the HTS bulk magnet generating a magnetic field of 3.27 T. The magnet sample was subsequently found to be fully magnetized in the open space of the static magnetic fields. We examined the magnetic field distributions when the magnetic poles were scanned twice to activate the magnet plate inversely with various overlap distances between the tracks of the bulk magnet. The magnetic field of the “rewritten” magnet reached the values of the magnetically saturated region of the material, showing steep gradients at the border of each magnetic pole. As a replacement for conventional pulse field magnetizing methods, this technique is proposed to expand the degree of freedom in the design of electromagnetic devices, and is proposed as a novel practical method for magnetizing rare-earth magnets, which have excellent magnetic performance and require intense fields of more than 3 T to be activated.     

城市港口

鹿特丹正在经历一个20世纪70年代开始的悲惨时期。这里缺少中高收入群体,当议会制定的前海地区重建计划公布时,它具有了巨大的潜力。它有一个普遍的社会隔膜,它仍然寄生在原有的建筑的城市的认知上。     

Molecular Mechanisms of Succinimide Formation from Aspartic Acid Residues Catalyzed by Two Water Molecules in the Aqueous Phase

Aspartic acid (Asp) residues are prone to nonenzymatic isomerization via a succinimide (Suc) intermediate. The formation of isomerized Asp residues is considered to be associated with various age-related diseases, such as cataracts and Alzheimer’s disease. In the present paper, we describe the reaction pathway of Suc residue formation from Asp residues catalyzed by two water molecules using the B3LYP/6-31+G(d,p) level of theory. Single-point energies were calculated using the MP2/6-311+G(d,p) level of theory. For these calculations, we used a model compound in which an Asp residue was capped with acetyl and methylamino groups on the N- and C-termini, respectively. In the aqueous phase, Suc residue formation from an Asp residue was roughly divided into three steps, namely, iminolization, cyclization, and dehydration, with the activation energy estimated to be 109 kJ mol⁻¹. Some optimized geometries and reaction modes in the aqueous phase were observed that differed from those in the gas phase.     

Autonomous driving control for ITS by using learning automaton network with multiple environments

In this paper, the application of the learning automaton (LA) network with multiple environments is proposed for the adaptive controller for ITS autonomous driving. The LA network, which we introduced previously, has the ability to learn which deals with both multiple reinforcement signals and information of multiple environments at the same time. This feature is found to be useful for improving the response of adaptation in dynamic environments such as highways. In order to evaluate the practical advantage of using the network, we designed a simulational highway system, constructed an autonomous travel controller using the simple LA and the LA network, and executed comparative experiments evaluating the performance of adaptation response and collision avoidance. The results show that the performance of the LA network with multiple environments is superior to that using simple LA application with regard to stability and safety. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 36–43, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10363     

Prediction of slippage onset condition between web and steel roller

This paper describes the theoretical modeling for the prediction of slippage onset condition between the paper web and steel roller with experimental verifications. For the first step of modeling, the occurrence of slippage is observed for the cases of uncoated paper (newsprint) and coated paper, and the relation between the slip ratio and roller velocity is measured by changing web tension. Two kinds of theoretical model are proposed, and the applicability of the models is confirmed experimentally.     

Properties of TiO2 prepared by acid treatment of BaTiO3

TiO₃ powders were prepared by acid treatment of BaTiO₃ and their properties were investigated. The BaTiO₃ powder was subjected to HNO₃ in concentrations ranging from 10⁻³ to 8 M at 90 °C for 0.5-6 h. Dissolution of BaTiO₃ and precipitation of TiO₂ occurred at acid concentrations of 2-5 M. BaTiO₃ dissolves completely to form a clear solution at reaction times of 0.5-1 h, but a rutile precipitate is formed after 2 h of acid treatment. By contrast, anatase is precipitated by adjusting the pH of the clear solution to 2-3 using NaOH or NH₄OH solution. The rutile crystals were small and rod-shaped, consisting of many small coherent domains connected by grain boundaries with small inclination angles and edge dislocations, giving them a high specific surface area (S_BET). With increasing HNO₃ concentration, the S_BET value increased from 100 to 170 m²/g while the crystallite size decreased from 25 to 11 nm. The anatase crystals obtained here were very small equi-axial particles with a smaller crystallite size than the rutile and S_BET values of about 270 m²/g (higher than the rutile samples). The photocatalytic activity of these TiO₂ was determined from the decomposition rate of Methylene Blue under ultraviolet irradiation. Higher decomposition rates were obtained with larger crystallite sizes resulting from heat treatment. The maximum decomposition rates were obtained in samples heated at 500-600 °C. The photocatalytic activity of the TiO₂ was found to depend more strongly on the sample crystallite size than on S_BET.     

Synchrony of fast-spiking interneurons interconnected by GABAergic and electrical synapses

Fast-spiking (FS) interneurons have specific types (Kv3.1/3.2 type) of the delayed potassium channel, which differ from the conventional Hodgkin-Huxley (HH) type potassium channel (Kv1.3 type) in several aspects. In this study, we show dramatic effects of the Kv3.1/3.2 potassium channel on the synchronization of the FS interneurons. We show analytically that two identical electrically coupled FS interneurons modeled with Kv3.1/3.2 channel fire synchronously at arbitrary firing frequencies, unlike similarly coupled FS neurons modeled with Kv1.3 channel that show frequency-dependent synchronous and antisynchronous firing states. Introducing GABA(A) receptor-mediated synaptic connections into an FS neuron pair tends to induce an antisynchronous firing state, even if the chemical synapses are bidirectional. Accordingly, an FS neuron pair connected simultaneously by electrical and chemical synapses achieves both synchronous firing state and antisynchronous firing state in a physiologically plausible range of the conductance ratio between electrical and chemical synapses. Moreover, we find that a large-scale network of FS interneurons connected by gap junctions and bidirectional GABAergic synapses shows similar bistability in the range of gamma frequencies (30-70 Hz).     

Dynamic structures of motor proteins myosin and kinesin, and switch protein troponin as detected by SDSL-ESR

We have studied biological nano-machines, motor and switch proteins operating as supramolecular complexes by electron spin resonance (ESR) and found key features of their molecular movements. In all the systems, the specific movements of elements or domains were detected and quite dynamic at nanometer scale. We have observed two broad but distinct orientations, separated by a 25 degrees axial rotation, of a spin label attached specifically to the light chain (LC) domain of myosin motor in the muscle fibers. The distribution became only narrower upon muscle activation. ESR spectrum from the spin label of the neck-linker of dimeric kinesin motor consisted of immobilized and mobilized components and did not exhibit nucleotide-dependent mobility change. The distance between two labels of kinesin dimer was also measured by spin dipole-dipole interaction, showing a broad distribution and a nucleotide-dependent change on the nanometer scale (>1.5 nm). These results suggest that two LC domains of myosin and two neck linkers of kinesin play a similar role for sliding movement using two conformations. The spin label of the skeletal (Tn)-I regulatory domain (TnIreg) showed a large mobility change by Ca2+ ion suggesting a Ca-induced switch movement of TnIreg. Spin dipole-dipole interaction showed that in reconstituted muscle fibers both skeletal and cardiac TnC undergo Ca2+-induced structural change that is thought to be essential for TnIreg movement. We also succeeded in fixing the newly-synthesized bifunctional spin label rigidly on the TnC molecule in solution, indicating that we can determine the precise coordinate of the spin principal axis of troponin on the oriented filament.     

Density Functional Theory of the Interface between Solid and Superfluid Helium 4

No Heading We report a calculation of the equilibrium profile of the interface between superfluid helium 4 and its solid phase at 0 K. To calculate the excess energy of the interface, we use the density functional theory that allowed us to obtain the equilibrium density of both phases. We compare our result to the experimental and to a previous microscopic calculation.PACS numbers: 68.08.–p, 67.80.–s, 67.40.Kh.