Preparation by gravity casting and hydrogen-storage properties of Mg–23.5 wt.%Ni–(5, 10 and 15 wt.%)La

Mg–23.5 wt.%Ni–(5, 10 and 15 wt.%)La alloys were prepared by gravity casting and their hydrogen-storage properties were examined after pulverizing. The gravity cast Mg–23.5Ni–(5, 10 and 15)La alloys consist of α-Mg, Mg₂Ni and Mg₁₇La₂ phases. The activated Mg–23.5Ni–10La alloy has the highest hydrogen-storage capacity of 4.96 wt.%H (from P–C–T curve) and the highest initial hydriding rate (hydrogen content 3.83 wt.%H at 10 min) with an initial hydrogen pressure in the channel of 11 bar H₂ at 573 K. This is attributed to its containing the largest amount of the Mg₁₇La₂ phase, which is easily dissociable during the hydriding reaction.     

The Change in Surface Properties of Magnetic Recording Media Under Pulsed Laser Application

The effects of laser heating on surface properties of magnetic recording media were systematically investigated through novel experiments and analytical simulations. When controlled laser pulses were applied onto the surface of a perpendicular magnetic recording (PMR) media, the measured values of surface roughness, surface free energy, and surface adhesive force were significantly increased with the number of the applied laser pulses. The heat transfer modeling and simulation was performed to evaluate the change in surface temperature of PMR media by the pulsed laser. The resulting temperature was not high enough to affect the carbon film and the underlying magnetic materials, but it could change the properties of the molecularly thin lubricant film on the media surface. Based on the thermal stability of the perfluoropolyether lubricant, it was found that the change of surface properties in experiments could be attributed to the thermal degradation of the lubricant through desorption process.     

Magnetic Field Effects on Transport Through a Strongly Correlated Dot Coupled to Luttinger Leads

The effects of the magnetic field and intralead electron interaction on the transport have been investigated in the Kondo regime by means of the nonequilibrium Green functions with the equation of motion method. The numerical results show that for weak intralead interaction, in addition to the Kondo dip zero bias, the differential conductance shows two peaks separated from the origin by the Zeeman energy. When the intralead interaction becomes moderately strong, the Zeeman splitting peaks turn into Zeeman splitting dips. With the further increase in the intralead interaction, all the dips disappear and the differential conductance is characterized by a power law scaling in bias voltage in the limit of the strong intralead interaction. Our results are valuable for analyzing transport in carbon nanotubes.     

Improved Elastic Contact Model Accounting for Asperity and Bulk Substrate Deformation

An improved elastic contact model for a single asperity system is proposed accounting for both the effects of bulk substrate and asperity deformations. The asperity contact stiffness is based on the Hertzian solution for spherical contact, and the bulk substrate stiffness on the solution of Hertzian pressure on a circular region of the elastic half-space. Depending on the magnitude of the applied load, as well as the geometrical and physical properties of the asperity and bulk materials, the bulk substrate could have considerable contribution to the overall contact stiffness. The proposed single asperity model is generalized using two parameters based on physical and geometrical properties, and is also verified using finite element analysis. A parametric study for a practical range of geometric and physical parameters is performed using finite element analysis to determine the range of validity of the proposed model and also to compare it with the Hertz contact model. The single asperity model is extended to rough surfaces in contact and the contact stiffness from the proposed model and the simpler Greenwood–Williamson asperity model are compared to experimental measurements.     

基于IP的全局网络存储解决方法

1.引言随着Internet的应用和普及,信息爆炸性地增长。因此,改善存储性能和提供7×24的可用性的压力也越来越大。传统的存储技术(BAS)采用并行SCSI或DAS技术,基于总线结构,无法提供足够灵活和可扩展的功能以满足如今对应用和存储快速布署的要求。     

Conscience online learning: an efficient approach for robust kernel-based clustering

Kernel-based clustering is one of the most popular methods for partitioning nonlinearly separable datasets. However, exhaustive search for the global optimum is NP-hard. Iterative procedure such as k-means can be used to seek one of the local minima. Unfortunately, it is easily trapped into degenerate local minima when the prototypes of clusters are ill-initialized. In this paper, we restate the optimization problem of kernel-based clustering in an online learning framework, whereby a conscience mechanism is easily integrated to tackle the ill-initialization problem and faster convergence rate is achieved. Thus, we propose a novel approach termed conscience online learning (COLL). For each randomly taken data point, our method selects the winning prototype based on the conscience mechanism to bias the ill-initialized prototype to avoid degenerate local minima and efficiently updates the winner by the online learning rule. Therefore, it can more efficiently obtain smaller distortion error than k-means with the same initialization. The rationale of the proposed COLL method is experimentally analyzed. Then, we apply the COLL method to the applications of digit clustering and video clustering. The experimental results demonstrate the significant improvement over existing kernel-based clustering methods.     

An efficient route to a porous NiO/reduced graphene oxide hybrid film with highly improved electrochromic properties

A porous NiO/RGO hybrid film is prepared by the combination of electrophoretic deposition and chemical-bath deposition. The porous hybrid film exhibits a noticeable electrochromism with reversible color changes from transparent to dark brown, and shows high coloration efficiency (76 cm(2) C(-1)), fast switching speed (7.2 s and 6.7 s) and better cycling performance compared with the porous NiO thin film. The enhancement of electrochromic performances are attributed to the reinforcement of the electrochemical activity of the RGO sheets and the greater amount of open space in the porous hybrid film which allows the electrolyte to penetrate and shorten the proton diffusion paths within the bulk of NiO.     

Short-channel amorphous-silicon thin-film transistors

Amorphous-silicon thin film transistors (TFTs) with submicrometer-long bottom-gate have been fabricated and their characteristics were evaluated. By the desirable effects of highly conductive source and drain of excimer-laser crystallized Si film, the mobility was hardly decreased from about 1.0 cm²/Vs for the 15-μm long TFT to about 0.9 cm²/Vs for the 0.5-μm long TFT. Detailed effects of the gate electrode thickness and length have been discussed on the TFT characteristics     

Comparison of conductometric humidity-sensing polymers

Films of differently modified PVA (polyvinyl alcohol), TA (phthalocyaninosilicon) and Nafion in different ionic forms (H⁺, Li⁺, and Na⁺) have been prepared by using casting methods. Impedance changes of the films with relative humidity are examined. The results demonstrate that the content and hydrophilicity of the hydrophilic group in PVA, ionization of TA, and the cation in Nafion have significant effects on sensing properties of the films.     

A 6.94-in. WVGA poly-Si TFT-LCD with integrated driver including sequential analog sampling circuits

By the integrated drive circuitry with laser crystallization process, the gate and data driver circuits required for full color WVGA(800 × RGB × 480) LCD are integrated on panel. The integrated driver comprises a sequential analog sampling data driver and a dual logic gate scanner for redundancy. The characteristics and uniformities of the LTPS (low temperature polycrystalline silicon) devices have been remarkably enhanced by applying stacked SiO₂ and SiN_x buffer layers and surface treatment.