Application of spinodal decomposition to produce metallic glass matrix composite with simultaneous improvement of strength and plasticity

An original two-step procedure, based on the miscibility gap between two elements, produced an in-situ bulk metallic glass matrix composite. The Zr-Ta binary alloy, which exhibits a large immiscible region in solid state, formed a two-phase mixture of Zr- and Ta-rich solid solution by phase separation. When the Zr-Ta binary alloy was remelted with Cu, Zr, and Ti, the Ta-rich solid solution, which has a high melting temperature, did not melt, while the remaining melt containing Zr-rich solid solution mixed with the other elements and solidified into an amorphous phase at lower temperatures. The improvement of strength in the composite indicates that the interfaces between the Ta-rich particles and the BMG matrix formed by phase separation are strong enough to hold a high interfacial cohesion strength.     

Development of high-performance concrete having high resistance to chloride penetration

The resistance to chloride penetration is one of the simplest measures to determine the durability of concrete, e.g. resistance to freezing and thawing, corrosion of steel in concrete and other chemical attacks. Thus, high-performance concrete may be defined as the concrete having high resistance to chloride penetration as well as high strength. The purpose of this paper is to investigate the resistance to chloride penetration of different types of concrete and to develop high-performance concrete that has very high resistance to chloride penetration, and thus, can guarantee high durability. A large number of concrete specimens have been tested by the rapid chloride permeability test method as designated in AASHTO T 277 and ASTM C 1202. The major test variables include water-to-binder ratios, type of cement, type and amount of mineral admixtures (silica fume, fly ash and blast-furnace slag), maximum size of aggregates and air-entrainment. Test results show that concrete containing optimal amount of silica fume shows very high resistance to chloride penetration, and high-performance concrete developed in this study can be efficiently employed to enhance the durability of concrete structures in severe environments such as nuclear power plants, water-retaining structures and other offshore structures.     

User required information modality and structure of in-vehicle navigation system focused on the urban commuter

Current available functions of In-Vehicle Navigation System (IVNS) are approaching to the multimedia system, and its information types become diverse by manufacturing company for accomplishing the on-board multimedia system. Concerning these trends, Human-Machine Interface (HMI) is regarded as more crucial issue for driver's safety and system usability. Also, this kind of issue includes determining the type of information that would be most beneficial to the particular group of users, when and where they need specific information, and the modality in which it should be presented. This paper conducted two kinds of experiments. One is an assessment of driver's mental workload of two kinds of modality to verify the developed Revision of NASA-TLX (RNASA-TLX), and the other is survey-based study to prioritizing the user required information that presented from IVNS. This experiment conducted in the real road situation using IVNS simulator especially focused on the urban commuter.     

电渣重熔高速钢轧材方形偏析成因分析

对电渣重熔高速钢轧材方型偏析形成原因进行了分析试验。结果认为，该方型偏析是由杂质元素Ａｌ、Ｓ及其夹杂物形成的成份偏析，是电渣重熔补缩阶段形成的锭型偏析，是在后续加工过程中形成的方形的。     

差分相干同步CDMA信道中的一种新的抗多址干扰接收机

本文考虑加性白噪声环境中的同步ＣＤＭＡ通信系统，给出了一种新的线性非相干解调接收机，同时给出了这种抗多址干扰接收机的误码率及渐近效率。结果表明，对于使用Ｇｏｌｄ码作特征码的ＣＤＭＡ系统，当用户数不大于特征码长度时，这种接收机的最小渐近效率是０．５     

Spectral Efficiency of WRAN Spectrum Overlay in the TV White Space

In this letter, we investigate the spectral efficiency of IEEE 802.22 wireless regional area network (WRAN) spectrum overlay when it is used in TV white space. Since 2004, when the FCC published the notice of proposed rule making 04‐186 to make use of unused TV spectrum, the IEEE 802.22 working group has been standardizing specifications for WRAN operations. There have been a few papers investigating the spectral efficiency of this, but their analyses were limited to the cases for various guard distances between WRAN base stations. Since WRAN base station (BS) power for WRAN service may differ from country to country, it is important to analyze the spectral efficiency for various WRAN BS powers. In this letter, we analyze the spectral efficiency of WRAN spectrum overlay as a function of the power of WRAN BSs. The simulation results show that spectral efficiency decreases as the power of WRAN BSs and guard distances increase.     

Phase-field study for the splitting mechanism of coherent misfitting precipitates in anisotropic elastic media

Through a phase-field study upon the splitting behavior and morphological evolution of coherent precipitates, we show that an interface instability driven by elastic anisotropy and a diffusion field can generate elastically induced splitting during diffusional phase transition. Particle splitting is triggered by interface grooving which advances by penetrating grooves into the interior of the particle. The sequential evolution of shapes during the splitting process is in good agreement with previous experiments.     

高铜、高砷、高硫金矿石或金精矿氰化浸金工艺

研究了铜、砷、硫矿物共生金矿石或金精矿，在氰化前用碱合剂预处理、在氰化过程中加入活化剂条件下，含铜(1％-6％)、砷(6.5％)、硫(30％)不干扰金的浸出，可使金浸出率从40％-50％提高至87％-94％，浸出速度快，经济效益较好。