Flexible Ceramics in the System KZr2(PO4)3–KAlSi2O6 Prepared by Mimicking the Microstructure of Itacolumite

A ceramic composite mimicking the pervasively cracked microstructure of flexible sandstone (itacolumite) was successfully synthesized by sintering two ceramic materials with different thermal expansion coefficients. A combination of granular KZr₂(PO₄)₃ (high thermal expansion) and powdered KAlSi₂O₆ (low thermal expansion) resulted in a material with a jigsaw-like three-dimensional cracking microstructure similar to that of itacolumite. The synthesized composite was found to exhibit ductile deformation.     

Pressureless sintering of negative thermal expansion ZrW2O8/Zr2WP2O12 composites

Negative thermal expansion material ZrW₂O₈/Zr₂WP₂O₁₂ composite was prepared by liquid phase sintering. The apparent density of ZrW₂O₈ without any sintering additive was about 3.7 g/cm³, corresponding to about 73% of its theoretical density. However, the relative density of the samples, sintered with more than 5 mol% P₂O₅ was about 90%. The identified phases were mainly ZrW₂O₈ with small amounts of WO₃, ZrO₂ and Zr₂WP₂O₁₂ by XRD. The intensity of Zr₂WP₂O₁₂ peaks increased with increasing P₂O₅ content. It was surmised that the melting of ZrO₂-P₂O₅ resulted in liquid phase formation, which is then converted to Zr₂WP₂O₁₂ on the final stage of sintering. Therefore, Zr₂WP₂O₁₂ phase was observed at the gap between the ZrW₂O₈ grains and at the triple junctions. The ceramics sintered with 20 mol% P₂O₅ showed a negative thermal expansion coefficient of − 4.0 × 10^− 6 °C^− 1.     

武汉市江汉路步行街使用现状及影响调研报告

近年来,随着我国城市建设的快速发展,城市空间布局在新的经济形势下发生了结构性的调整。由于诸多历史原因,旧城商业街在现代生活中矛盾日益突出,而步行街这种形式逐渐成为一种热潮。这样的一种发展在当今社会究竟是怎样的一种趋势,它对城市生活究竟有多少影响,它触发了人群的哪些活动都是我们需要思考的问题。针对这一思路,我们以汉口的江汉路步行街为例,对人群的活动进行观察、研究,发现其中存在的问题,并对其改进有一些建议。     

Improving the shear strength by silane treatments of aluminum for direct joining of phenolic resin

Phenolic resin was directly joined to aluminum using three different silane coupling agents, AEAPS (N-(β-aminoethyl)-γ-aminopropyl trimethoxy silane), McPS (γ-mercaptopropyl trimethoxy silane), and GPS (γ-glycidoxypropyl trimethoxy silane). The impacts of surface treatment conditions on the joint strength and interfacial properties were investigated. The joint strength was raised about 1.6–2.6 times that of the untreated aluminum when joined to phenolic resin. The chemical bonds were formed by the phenolic resin and the amino groups in AEAPS, while entanglement between the phenolic resin and the methylene groups in McPS was obtained. The results of cyclic thermal loading indicated that the interfaces were deteriorated and joint strength was decreased using GPS as the silane coupling agent when the number of cycles was increased. The interface was enhanced and the shear strength of joints was not decreased using AEAPS as the silane coupling agent.     

First-principles study of spin-dependent transport through graphene/BNC/graphene structure

First-principles study on the electronic structure and transport property of the boron nitride sheet (BNC) structure, in which a triangular graphene flake surrounded by a hexagonal boron nitride sheet, is implemented. As the graphene flake becomes small and is more isolated by the boron nitride region, the magnetic ordering of the flake increases. When the BNC structure is connected to the graphene electrodes, the spin-polarized charge-density distribution appears only at the triangular graphene flake region, and the electronic structure of the graphene electrode is not spin polarized. First-principles transport calculation reveals that the transport property of the BNC structure is spin dependent.     

A neuromodulation model of behavior selection in the fighting behavior of male crickets

The results of neurophysiological research have indicated the important role of neuromodulation in behavior decisions during fighting between male crickets. To understand such a dynamic behavior generation mechanism, we attempt to construct a neuromodulation model of behavior selection for the fighting behavior of a cricket. In this paper, we propose a dynamic system model of neuromodulation with the efficacy based on neurophysiological knowledge, facts, and hypotheses from the viewpoint of synthesis. The efficacy of the sensory processing center is introduced to our previous model and its dynamics is influenced by the frequency of the interactions with the other cricket. Utilizing an extended neuromodulation model, computer simulations related to a multiple-individual environment were carried out, and the results are discussed. In particular, the properties related to the standard deviation of the value of octopamine in several population density cases are discussed.     

Characteristics of hydrophobicity loss on silicone rubber surface during a dynamic drop test with direct current voltage application

Dynamic drop test for studying the temporal lowering of hydrophobicity on the surface of silicone rubber with direct current voltage application was carried out. In this study, we evaluated the influence of the temporal lowering of hydrophobicity under various conductivities and dropping rates for water droplets. As a result, it was found that the dropping rate and the conductivity of water droplets greatly influenced the hydrophobicity loss time on the surface of silicone rubber.