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Ni and Co metallic microparticles with submicron size were synthesized with a simple wet chemical reduction method at a relatively low temperature. Then their morphologies and structures were characterized by SEM and XRD. Ni metallic microparticles have spherical-shape morphology with fcc crystalline structure, however, Co has a distinct leaf-like morphology with the fcc and hcp mixed phases crystalline structures. For the characterization of their electromagnetic properties, paraffin matrix composites containing different molar ratio Ni and Co mixture powder as fillers were prepared. It was found that both the electromagnetic properties and electromagnetic microwave absorption performances of absorber layer were remarkably influenced by Ni/Co molar ratio. The electromagnetic microwave absorption performances were significantly improved by blending Ni and Co metallic microparticles into paraffin matrix with changing Ni/Co molar ratio, and enhanced mechanism were discussed.

In this letter, we report that a new bulk metallic glass (BMG) of Ti 20 Zr 20 Cu 20 Ni 20 Be 20 , with a critical diameter of 3 mm, has been successfully fabricated using copper mold casting method. Different from most reported BMGs which possess one or two main constituents, this newly developed BMG possesses five elements with equal atomic concentration, which has been defined as high entropy alloy. This high entropy bulk metallic glass (HE-BMG) exhibits high fracture strength of 2315 MPa but a brittle behavior. The glass forming ability, mechanical property and phase transformation after annealing of the HE-BMG are discussed in detail. And a way for designing high entropy bulk glassy alloy has been proposed.

The strategy to manipulate nanoscale building blocks into well-organized heterostructures is very important to both material synthesis and nanodevice applications. In this work, highly-ordered ZnO/PbS core/shell nanowire arrays were fabricated by a facile and low temperature chemical route. Large area and well-aligned ZnO nanowire arrays were firstly fabricated on conductive glass substrates, and then the synthesis of ZnO/ZnS and ZnO/PbS core/shell nanowire arrays were realized by a chemical conversion method. The morphology, structure, and composition of the obtained nanostructures were confirmed by field-emission scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction measurements. The optical properties of the synthesized nanostructures were investigated by micro-Raman and photoluminescence spectroscopy. In the synthesized ZnO/PbS core/shell nanowire arrays, the ZnO cores can provide direct conduction pathways for electron transport and PbS shells possess superior photoelectric performance. Therefore, the obtained ZnO/PbS core/shell nanostructures may have potential application in photovoltaic devices.

Iron-based bulk metallic glasses (BMGs) are attractive due to their excellent magnetic properties. It is known that increasing the iron content in alloys would enhance the magnetic property of glassy alloys, but would reduce their glass forming ability. Despite researchers are keen to develop Fe-based BMGs with high Fe content, BMG with Fe content higher than 79 at.% has not been reported. Here we report that Fe-based BMGs with Fe content as high as 78 ∼ 81 at.% have been successfully prepared. The as-prepared Fe81Mo1P7.5C5.5B2Si3 BMG possesses a saturation magnetization of 1.64 T, which is significantly higher than the reported value in BMGs.

The strategy to manipulate nanoscale building blocks into well-organized hierarchical architectures is very important to both material synthesis and nanodevice applications. In this work, hierarchical ZnO nanostructures with controllable morphology were synthesized by a two-step chemical route. At step-one, hexagonal- and spherical-shaped ZnO nanostructures were deposited on glass slide substrates. At step two, the morphology of hierarchical ZnO nanostructures could be effectively controlled by changing the composition of solutions. The method described here is a simple and reproducible process, which does not require any templates, catalysts, or surfactants, but can control the morphology of ZnO crystals from simple to complex. The morphologies and structures of the products were characterized by field-emission scanning electron microscopy and X-ray diffraction measurements. Room-temperature photoluminescence spectra demonstrate that the variety of nanostructures can cause the variation of the photoluminescence intensity, suggesting that the controlled morphologies can be used to modulate the optical properties of ZnO nanostructures.

Northern rural residential heating in winter is the main reason for the high energy using in rural residential. Rural residential heating facilities exist several universal problems, such as thermal efficiency of rural residential heating facilities is commonly low,surface temperature of kang is uneven and surface temperature of firewall is too high. According to the problems and combining the characteristics of phase change energy storage technology, phase change materials were used in different heating systems. Based on the characteristics of different types of phase change materials and the requirement of the human body comfort temperature,it is particularly important to select phase change energy-storage materials which are suitable for different heating system and whose temperature ranges are among 15-18°C, 24-26°C, 24-35°C and 24-55°C. Through the selection of the phase change materials, we get three types of phase change thermal storage materials which are suitable for rural residential heating systems, which provide analysis method and basic reference for the selection of the phase change material to heating systems, ensured the indoor comfort temperature and improved the energy-saving efficiency of rural residential.

The kinetic behaviour of Tc-d,1-hexamethylpropyleneamine oxime (Tc-d,1-HMPAO) complex being an efficacious cerebral perfusion imaging agent in aqueous solution was investigated by means of solvent extraction and spectrophotometric methods. The complex of Tc-d,1-HMPAO is stable in basic solution. In an acid solution, however, it is attacked by hydrogen ions forming hydrophilic complexes. As final products, pertechnetate and reduced hydrolysed technetium (TcO2) were recognized. The rate equation is simply expressed as R = k1 [H+][Tc-d,1-HMPAO] in a high concentration of hydrogen ion, whereas it becomes complicated when a decrease in the concentration of hydrogen ion occurs. The respective decomposition rate constants were determined. A strong correlation between [H+] and k values (rate constant) was found, supporting the hypothesis that the concentration of the hydrogen ion is the predominant factor for the conversion of the lipophilic complex to its hydrophilic derivatives.

The present work put forward the research strategy of speech sound perception by the mismatch negativity (MMN). Why, what and how the MMN was employed for study on speech sound perception was discussed. MMN reflects sensory memory functioning and can be used to study the temporal-discrimination accuracy in the auditory system. Based on the analysis of the speech perception model and the character of MMN, it proves that MMN is suitable for the research of speech sound perception. A reasonable and step-by-step research strategy is proposed to study the encoding of acoustics and phonetics information in the central auditory cortex by MMN. In order to obtain reliable and remarkable MMN, the recording technology and some parameters in the experiment are discussed. Proper data analysis methods and the perspectives for application are discussed briefly.