Bioinspired interactive neuromorphic devices

The performance of conventional computer based on von Neumann architecture is limited due to the physical separation of memory and processor. By synergistically integrating various sensors with synaptic devices, recently emerging interactive neuromorphic devices can directly sense/store/process various stimuli information from external environments and implement functions of perception, learning, memory, and computation. In this review, we present the basic model of bioinspired interactive neuromorphic devices and discuss the performance metrics. Next, we summarize the recent progress and development of bioinspired interactive neuromorphic devices, which are classified into neuromorphic tactile systems, visual systems, auditory systems, and multisensory system. They are discussed in detail from the aspects of materials, device architectures, operating mechanisms, synaptic plasticity, and potential applications. Additionally, the bioinspired interactive neuromorphic devices that can fuse multiple/mixed sensing signals are proposed to address more realistic and sophisticated problems. Finally, we discuss the pros and cons regarding to the computing neurons and integrating sensory neurons and deliver the perspectives on interactive neuromorphic devices at the material, device, network, and system levels. It is believed the neuromorphic devices can provide promising solutions to next generation of interactive sensation/memory/computation toward the development of multimodal, low-power, and large-scale intelligent systems endowed with neuromorphic features.     

Microstructure,mechanical and wear properties of aluminum borate whisker reinforced aluminum matrix composites

The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker (ABOw) (5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventional powder metallurgy technique. The aluminium powder and the whisker were effectively blended by a semi-powder metallurgy method. The blended powder mixtures were cold compacted and sintered at 600 °C. The sintered composites were characterized for microstructural features by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. Porosity in the composites with variation in ABOw contents was determined. The effect of variation in content of ABOw on mechanical properties, viz. hardness, bending strength and compressive strength of the composites was evaluated. The dry sliding wear behaviour was evaluated at varying sliding distance at constant loads. Maximum flexural strength of 172 MPa and compressive strength of 324 MPa with improved hardness around HV 40.2 are obtained in composite with 10 wt.% ABOw. Further increase in ABOw content deteriorates the properties. A substantial increase in wear resistance is also observed with 10 wt.% ABOw. The excellent combination of mechanical properties of Al−10wt.%ABOw composites is attributed to good interfacial bonds, less porosity and uniformity in the microstructure.     

石墨烯/碱式硫酸镁晶须/PVC复合材料的制备及性能表征

以改进的Hummers法制备还原氧化石墨烯(RGO),以RGO和碱式硫酸镁晶须(MHSHw)为填料,采用机械球磨法制备RGO/MHSHw/PVC复合粉料,经平板硫化机热压成型得三相复合板材。考察了RGO和MHSHw对复合材料电阻率、阻燃性能及力学性能的影响。结果表明:RGO具有很好的片层结构和导电性;当MHSHw添加量为5%,RGO添加量为1%时,RGO/MHSHw/PVC复合板材的表面电阻率为4×106Ω/square,比纯PVC下降8个数量级,达到了商业抗静电效果,拉伸强度达到最大值17.61 MPa,比纯PVC提高了44.04%,复合板材氧指数>33%,具有阻燃性能,得到力学性能优良兼具有抗静电和阻燃性能的复合材料。     

强风化砂岩边坡锚筋桩布置方式及支护作用研究

强风化顺层砂岩边坡具有节理裂隙发育、强度低的特征,导致开挖过程中出现边坡稳定问题。单纯的锚杆锚索支护无法满足边坡稳定性需求,在现场抗滑桩施工困难的情况下,选用经济、高效、施工便利的锚筋桩结合锚杆锚索对强风化顺层砂岩边坡进行支护。针对强风化砂岩破碎且强度低的特性,考虑高压注浆的劈裂作用,通过FLAC 3D数值模拟进行方案比选,得到适用于强风化砂岩边坡的锚筋桩多角度交叉布置方案。根据试验段边坡锚筋桩监测数据,分析强风化顺层砂岩边坡锚筋桩作用机理,验证了多角度交叉布置锚筋桩对强风化顺层砂岩边坡的加固效果。     

基于四端E-SOP的有源配电网运行效率优化

柔性软开关SOPs(soft open points)通过准确控制换流器有功功率交换,提供了现有配电自动化体系所不具备的实时精细潮流调节优化能力。为了解决SOP对有源配电网运行效率的优化成效问题,本文首先建立了带有储能装置的四端SOP即E-SOP(SOP with energy storage)的接入拓扑和数学模型,考虑了四端E-SOP换流器和直流侧储能装置的运行约束。其次,建立了基于四端E-SOP的有源配电网运行效率优化模型。然后,利用半定规划方法对模型进行了线性化求解。最后,通过算例验证了所提方法的有效性和实用性。     

Semi-supervised Learning with Graph Convolutional Networks Based on Hypergraph

Neural Processing Letters - Graph convolutional networks (GCNs), which rely on graph structures to aggregate information of neighbors to output robust node embeddings, have been becoming a popular...     

Interdiffusion behaviors and mechanical properties of Zn–Cr system

Diffusion couple technique has been utilized to study the interdiffusional behaviors of Zn–Cr system. Two intermetallic compounds (Zn₁₃Cr, Zn₁₇Cr) have been found in the diffusion zone between 598 K and 653 K. For the existence of Zn₁₃Cr phase, the incremental diffusion couple has been used to confirm, and the results show that the Zn₁₃Cr phase can be determined in the present work. However, the thickness of Zn₁₃Cr is very thinner than that of Zn₁₇Cr, which indicate the growth of Zn₁₃Cr is very slow. The thickness of Zn₁₇Cr satisfied the parabolic growth law. EPMA was used to obtain the composition profiles and the interdiffusion coefficients of Zn₁₃Cr, Zn₁₇Cr and Zn (hcp) have been extracted by forward simulation analysis embedded in ‘Pydiffusion’ code. The mechanical properties of Zn₁₇Cr were also determined by nanoindentation technique, and the hardness and Young's modulus of Zn₁₇Cr is 3.01 GPa and 165.78 GPa, respectively.     

Influences of chitosan on freeze–thaw stability of Arenga pinnata starch

This study aims to investigate chitosan (CS) with five different molecular weight (Mw) on freeze–thaw stability of Arenga pinnata starch (APS) gel subjected to five freeze–thaw cycles (FTC). The syneresis of APS gels was reduced by adding CS and the APS gel with high Mw CS had lower syneresis duo to a higher water holding capacity (P < 0.05). The addition of CS significantly decreased the hardness and molecular ordered structure of APS gel. In addition, CS could improve the microstructural stability. The results suggested that CS could effectively improve the freeze–thaw stability of APS gel, and CS with higher Mw might have more practical utility to improve stability of APS gel.