高密度磁记录用部分晶化钡铁氧体薄膜

对于沉积态非晶薄膜,通过严格控制其块速热处理时间,从而制备出了部分晶化钡铁本薄膜,和学显微镜（ＡＦＭ）观察表明,与完全晶化的薄膜相比,部分晶化的薄膜具有更光滑的表面,振动样品磁强计（ＶＳＭ）的测量结果表明,这种薄膜具有非常低的△Ｍ值,这主要是由于磁性粒子之间存在非磁性相,使和磁性粒子之间的磁耦合减小的缘故。     

Development and performance evaluation of a GC-FPD method for quantification of ethephon in feeds

An analytical method of ethephon in feeds by GC-FPD was developed. Ethephon was extracted with ethyl acetate-hydrochloric acid (100 : 1) from feed samples. The extract was treated with added trimethylsilyldiazomethane in acetone-acetic acid (99 : 1) and this methylation procedure was repeated three times. Methylated ethephon was cleaned up on a graphitized carbon mini-column and a silicagel mini-column, and determined by GC-FPD. A method performance study in 7 laboratories was conducted with three kinds of samples spiked with ethephon at 10 mg/kg, 1 mg/kg and 0.5 mg/kg. The recovery of ethephon ranged from 81.8% to 90.8% (the reproducibility standard deviation (RSDr) were within 11%) and HorRat values were 0.58 to 0.94. The limit of detection (S/N≧3) and the limit of quantitation (S/N≧10) of ethephon in samples except hay were 0.02 mg/kg and 0.05 mg/kg, respectively. In the case of hay, the corresponding values were 0.2 mg/kg and 0.5 mg/kg, respectively.     

Surrogate Constraints Algorithm for Reliability Optimization Problems with Multiple Constraints

This paper presents a surrogate constraints algorithm for solving nonlinear programming, nonlinear integer programming, and nonlinear mixed integer programming problems. The algorithm contains a new technique for generating a succession of vector values of surrogate multiplier (ie, surrogate problems). By using this technique, a computer can keep a polyhedron, which is a vector space of surrogate multipliers to be considered at a certain time, in its memory. Furthermore it can cut the polyhedron by a given hyperplane, and produce the remaining space as the next polyhedron. Simple examples are included.     

Competition Between the Superfluid Overlayer and the Mobile Solid Layer of 3He-4He Mixture Films on Porous Gold

In the previous quartz crystal microbalance measurements for ⁴He films adsorbed on porous gold, we have observed a competition between superfluidity and slippage: In low areal densities, the resonance frequency increases gradually below T _S due to the slippage of solid layer, while at high areal densities the slippage disappears and the superfluid onset of liquid overlayer is observed at T _C . In the crossover region, the slippage below T _S is suddenly suppressed at T _D , which is much lower than T _C . In the present work, we introduced a small amount of ³He onto ⁴He films, and studied the competition as a function of ³He areal density ρ ₃. As ρ ₃ is increased, T _C is monotonically lowered. In contrast, T _D increases up to a certain value of ρ ₃, and then turns over to decrease in parallel to T _C .     

Selective adsorption of precious metals from hydrochloric acid solutions using porous carbon prepared from barley straw and rice husk

Porous carbon was prepared by carbonization from agro-waste such as rice husk and barley straw to evaluate the adsorption of precious and base metals from metal solutions. The effects of hydrochloric acid concentration, metal ion concentration, and contact time on adsorption were examined. Rice husk carbon was found to be highly selective for Au(III) and inert to Pt(IV), Pd(II) and other base metals. Barley straw carbon adsorbed these three precious metal ions, but was inert to base metal ions such as Cu(II), Fe(III) and Ni(II). The maximum adsorption capacity of rice husk carbon for Au(III) was 0.76 mol/kg and the maximum adsorption capacity of barley straw carbon for Au(III), Pt(IV) and Pd(II) was 1.47, 0.39 and 0.64 mol/kg, respectively. The effectiveness of recovery of precious metals from industrial solution was also tested and barley straw carbon was found to be highly efficient and selective for the targeted metal ions in the presence of excess of other metal ions. Rice husk and barley straw carbon are thus potential alternatives to commercially available activated carbon as they have high selectivity and are efficient with low production costs.     

Phase-separation behavior in a binary mixture fluid layer subjected to a vertical temperature gradient

The phase separation behavior in a layer of an isobutyric acid (IBA)-water binary mixture was observed from the bottom and side of the layer, where the layer was subjected to a vertical temperature gradient spanning the critical temperature. As a result, the following conclusions were obtained. (1) Patterns characterized by a polygonal cell including one droplet, similar to those observed by Assenheimer et al. (Physica A 208 (1994) 373), were formed in a relatively thick liquid layer, e.g., thick, in a limited range of the temperature gradient, although the patterns ultimately disappeared. (2) The growth and extinction rates of the phase-separated droplets increased with ΔT/d, and increased particularly rapidly at high ΔT/d. (3) The formation of the pattern of polygonal cells each with a droplet is considered to be due to thermocapillary motion along the droplet. (4) The concentration-driven buoyancy convection affects the growth rate of the phase-separated droplets. (5) The extinction rate of the phase-separated droplets at the late stage is affected by the thermocapillary motion along the droplet surface.     

Simulation verification for the robustness of passive compass gait with a joint stiffness adjustment

A passive walking robot can achieve a smooth gait without any sensory feedback while walking down a slope. This phenomenon is based on the transformation of potential energy into kinetic energy in the legs. Although the entrainment is observed in a passive gait motion, there is a possibility that the passive gait cannot be achieved in the case of variations in physical parameters, initial conditions, and disturbances. To realize a robust passive gait against variations in physical parameters, this paper proposes a passive gait system that possesses a joint stiffness adjustment. Targeting a compass model, this paper investigates the effectiveness of the proposed method for a passive gait against variations in slope angle and hip joint mass through simulation. As a result, the simulation results show that this method especially has strong robustness against the slope angle variation.     

Gestural cue analysis in automated semantic miscommunication annotation

The automated annotation of conversational video by semantic miscommunication labels is a challenging topic. Although miscommunications are often obvious to the speakers as well as the observers, it is difficult for machines to detect them from the low-level features. We investigate the utility of gestural cues in this paper among various non-verbal features. Compared with gesture recognition tasks in human-computer interaction, this process is difficult due to the lack of understanding on which cues contribute to miscommunications and the implicitness of gestures. Nine simple gestural features are taken from gesture data, and both simple and complex classifiers are constructed using machine learning. The experimental results suggest that there is no single gestural feature that can predict or explain the occurrence of semantic miscommunication in our setting.     

Effects of lithium salts on ASR gel composition and expansion of mortars

Suppression of alkali-silica reaction (ASR) expansion in mortar and concrete by the addition of lithium salts has been confirmed by some workers. It has been revealed that lithium hydroxide tended to reduce the reaction between sodium or potassium hydroxide and reactive silica, and that the ASR gel incorporating lithium was less expansive. However, it has not been reported how the addition of a lithium salt influenced the composition of the ASR gel. The calcium in ASR gel is considered to play an important role in the expansion of the gel. Thus, it is significant to characterize ASR gel composition in mortars containing lithium salts by BSE-EDS analysis. This study aims to discuss the mechanisms of suppression of ASR expansion in mortar by lithium salts from the viewpoint of ASR gel composition. The average CaO/SiO₂ ratio in ASR gels decreased with increasing amount of added lithium salts. It should be noted that the extent of variations in the CaO/SiO₂ ratio in ASR gels significantly decreased with increasing amount of lithium salts. The addition of relatively small amounts of LiOH and Li₂CO₃ resulted in increased expansion. We also obtained an unexpected result that ASR gels became homogeneous with respect to their CaO contents at high dosage levels. However, the reduction in average CaO/SiO₂ ratios and the homogenization in the CaO content of ASR gels due to the addition of lithium salts may not be related to the expansion of mortars.     

Relation between formation rates of methane and hydrogen on pyrolysis of coal under pressure

In an earlier paper¹ it became clear that secondary-methane formation occurs under certain experimental conditions during pyrolysis of coal. In order to study this more deeply, the evolution rates of methane and hydrogen were measured simultaneously for an anthracite and a lignite. The secondary-methane formation was accompanied by a corresponding decrease in hydrogen formation. It is suggested that secondary-methane formation occurs according to the equation C + 2H₂ = CH₄ on an average and is proportional to the partial pressure of evolved hydrogen.