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81.
Applied Intelligence - With the development of sensor and communication technology, industrial systems have accumulated a large amount of data. This data has provided new perspectives and methods... 相似文献
82.
Caifang Gao Mu-Pai Lee Mengjiao Li Ko-Chun Lee Feng-Shou Yang Che-Yi Lin Kenji Watanabe Takashi Taniguchi Po-Wen Chiu Chen-Hsin Lien Wen-Wei Wu Shu-Ping Lin Wenwu Li Yen-Fu Lin Junhao Chu 《Advanced functional materials》2021,31(5):2005182
The human brain is often likened to an incredibly complex and intricate computer, rather than electrical devices, consisting of billions of neuronal cells connected by synapses. Different brain circuits are responsible for coordinating and performing specific functions. The reward pathway of the synaptic plasticity in the brain is strongly related to the features of both drug addiction and relief. In the current study, a synaptic device based on layered hafnium disulfide (HfS2) is developed for the first time, to emulate the behavioral mechanisms of drug dosage modulation for neuroplasticity. A strong gate-dependent persistent photocurrent is observed, arising from the modulation of substrate-trapping events. By controlling the polarity of gate voltage, the basic functions of biological synapses are realized under a range of light spiking conditions. Furthermore, under the control of detrapping/trapping events at the HfS2/SiO2 interface, positive/negative correlations of the An/A1 index, which significantly reflected the weight change of synaptic plasticity, are realized under the same stimulation conditions for the emulation of the drug-related addition/relief behaviors in the brain. The findings provide a new advance for mimicking human brain plasticity. 相似文献
83.
Rong Zhu Juan Li Lisen Lin Jibin Song Huanghao Yang 《Advanced functional materials》2021,31(10):2005709
Plasmonic gold nanocrystal represents plasmonic metal nanomaterials, and has a variety of unique and beneficial properties, such as optical signal enhancement, catalytic activity, and photothermal properties tuned by local temperature, which are useful in physical, chemical, and biological applications. In addition, the inherent properties of predictable programmability, sequence specificity, and structural plasticity provide DNA nanostructures with precise controllability, spatial addressability, and targeting recognition, serving as ideal ligands to link or position building blocks during the self-assembly process. Self-assembly is a common technique for the organization of prefabricated and discrete nanoparticle blocks for the construction of extremely sophisticated nanocomposites. To this end, the integration of DNA nanotechnology with Au nanomaterials, followed by assembly of DNA-functionalized Au nanomaterials can form novel functional Au nanomaterials that are difficult to obtain through conventional methods. Here, recent progress in DNA-assembled Au nanostructures of various shapes is summarized, and their functions are discussed. The fabrication strategies that employ DNA for the self-assembly of Au nanostructures, including dimers, tetramers, satellites, nanochains, and other nanostructures with more complex geometric configurations are first described. Then, the characteristic optical properties and applications of biosensing, bioimaging, drug delivery, and therapy are discussed. Finally, the remaining challenges and prospects are elucidated. 相似文献
84.
Guandong Liang Guoxun Sun Jianqiang Bi Weili Wang Xiangning Yang Yonghan Li 《Ceramics International》2021,47(2):2058-2067
Uniformly dispersed boron nitride nanosheets (BNNSs) reinforced silicon nitride (Si3N4) composites were prepared by surface modification assisted flocculation combined with SPS sintering. In order to improve the dispersibility of the BNNSs in the composites, the liquid phase stripped BNNSs are surface functionalized by a two-step covalently modification. The amino-modified BNNSs (NH2-BNNSs) and Si3N4 powders have opposite surface potential, mixed evenly by electrostatic interaction during flocculation. The results showed that mechanical properties of Si3N4 composites were obviously enhanced by adding NH2-BNNSs. The fracture toughness and bending strength of Si3N4 composites added 0.75 wt% NH2-BNNSs were increased by 34% and 28%, respectively, compared with monolithic Si3N4. Toughening mechanisms are synergistic action of the torn, pull-out or bridging of BNNSs and crack deflection mechanisms with microstructural analyzes. The dielectric properties of the Si3N4 ceramics are also improved after the addition of NH2-BNNSs. 相似文献
85.
采用直流磁控溅射和后退火氧化工艺在p型GaAs单晶衬底上成功制备了n-VO_2/pGaAs异质结,研究了不同退火温度和退火时间对VO_2/GaAs异质结性能的影响,并分析其结晶取向、化学组分、膜层质量以及光电特性。结果表明,在退火时间2 h和退火温度693 K下能得到相变性能最佳的VO_2薄膜,相变前后电阻变化约2个数量级。VO_2/GaAs异质结在308 K、318 K和328 K温度下具有较好的整流特性,对应温度下的阈值跳变电压分别为6.9 V、6.6 V和6.2 V,该结果为基于VO_2相变特性的异质结光电器件的设计与应用提供了可行性。 相似文献
86.
Kun Yang Yachun Wang Penghui Lei Tiankai Yao Dong Zhao Jie Lian 《Journal of the European Ceramic Society》2021,41(12):6018-6028
Chemical durability of lanthanide zirconates (A2Zr2O7) (A = La-Yb) under near-field environments is important for evaluating their application as potential nuclear waste forms. In this work, A2Zr2O7 (A = La-Yb) are synthesized by spark plasma sintering with controlled microstructure and their chemical durability are evaluated in a nitric acid solution (pH = 1). Scanning transmission electron microscopy analysis reveals an amorphous passivation film either enriched with Zr or lanthanide. The complex chemistry of the passivation films can be correlated with a transition in corrosion mechanisms from a preferential release of lanthanide in La2Zr2O7 to a preferential release of Zr in Er2Zr2O7 and Yb2Zr2O7. These results suggest a dominant mechanism of incongruent dissolution and surface reorganization for the formation of passivation films. Strong correlations are identified between the leaching rates and cation ionic size, ionic potential, electronegativity differences between A-site cation and Zr, and bonding valence sum of oxygen, suggesting important impacts of structural and bonding characteristics in controlling chemical durability of lanthanide zirconates. 相似文献
87.
Matrix Manipulation of Directly-Synthesized PbS Quantum Dot Inks Enabled by Coordination Engineering
Fei Li Yang Liu Guozheng Shi Wei Chen Renjun Guo Dong Liu Yaohong Zhang Yongjie Wang Xing Meng Xuliang Zhang You Lv Wei Deng Qing Zhang Yao Shi Yifan Chen Kai Wang Qing Shen Zeke Liu Peter Müller-Buschbaum Wanli Ma 《Advanced functional materials》2021,31(45):2104457
The direct-synthesis of conductive PbS quantum dot (QD) ink is facile, scalable, and low-cost, boosting the future commercialization of optoelectronics based on colloidal QDs. However, manipulating the QD matrix structures still is a challenge, which limits the corresponding QD solar cell performance. Here, for the first time a coordination-engineering strategy to finely adjust the matrix thickness around the QDs is presented, in which halogen salts are introduced into the reaction to convert the excessive insulating lead iodide into soluble iodoplumbate species. As a result, the obtained QD film exhibits shrunk insulating shells, leading to higher charge carrier transport and superior surface passivation compared to the control devices. A significantly improved power-conversion efficiency from 10.52% to 12.12% can be achieved after the matrix engineering. Therefore, the work shows high significance in promoting the practical application of directly synthesized PbS QD inks in large-area low-cost optoelectronic devices. 相似文献
88.
Andrew N. Kuhn Haidong Zhao Uzoma O. Nwabara Xiaofei Lu Mingyan Liu Yung-Tin Pan Wenjin Zhu Paul J. A. Kenis Hong Yang 《Advanced functional materials》2021,31(26):2101668
Copper catalysts are widely studied for the electroreduction of carbon dioxide (CO2) to value-added hydrocarbon products. Controlling the surface composition of copper nanomaterials may provide the electronic and structural properties necessary for carbon-carbon coupling, thus increasing the Faradaic efficiency (FE) towards ethylene and other multi-carbon (C2+) products. Synthesis and catalytic study of silver-coated copper nanoparticles (Cu@Ag NPs) for the reduction of CO2 are presented. Bimetallic CuAg NPs are typically difficult to produce due to the bulk immiscibility between these two metals. Slow injection of the silver precursor, concentrations of organic capping agents, and gas environment proved critical to control the size and metal distribution of the Cu@Ag NPs. The optimized Cu@Ag electrocatalyst exhibited a very low onset cell potential of −2.25 V for ethylene formation, reaching a FE towards C2+ products (FEC2+) of 43% at −2.50 V, which is 1.0 V lower than a reference Cu catalyst to reach a similar FEC2+. The high ethylene formation at low potentials is attributed to enhanced C C coupling on the Ag enriched shell of the Cu@Ag electrocatalysts. This study offers a new catalyst design towards increasing the efficiency for the electroreduction of CO2 to value-added chemicals. 相似文献
89.
Reliable joints of Ti3SiC2 ceramic and TC11 alloy were diffusion bonded with a 50 μm thick Cu interlayer. The typical interfacial structure of the diffusion boned joint, which was dependent on the interdiffusion and chemical reactions between Al, Si and Ti atoms from the base materials and Cu interlayer, was TC11/α-Ti + β-Ti + Ti2Cu + TiCu/Ti5Si4 + TiSiCu/Cu(s, s)/Ti3SiC2. The influence of bonding temperature and time on the interfacial structure and mechanical properties of Ti3SiC2/Cu/TC11 joint was analyzed. With the increase of bonding temperature and time, the joint shear strength was gradually increased due to enhanced atomic diffusion. However, the thickness of Ti5Si4 and TiSiCu layers with high microhardness increased for a long holding time, resulting in the reduction of bonding strength. The maximum shear strength of 251 ± 6 MPa was obtained for the joint diffusion bonded at 850 °C for 60 min, and fracture primarily occurred at the diffusion layer adjacent to the Ti3SiC2 substrate. This work provided an economical and convenient solution for broadening the engineering application of Ti3SiC2 ceramic. 相似文献
90.
Yi Qin Tao Xiong Ting Zhao Jianfeng Zhu Jun Yang Yi Liu Xingang Kong Xiaohan Li 《Ceramics International》2021,47(9):12641-12650
The strengthening method of multi-element M-site solid solution is a common approach to improve mechanical properties of MAX phase ceramic. However, the research on capability of multi-element A-site solid solution to improve mechanical properties has rarely been reported. Thereupon, quasi-high-entropy MAX phase ceramic bulks of Ti2(Al1?xAx)C and Ti3(Al1?xAx)C2 (A = Ga, In, Sn, x = 0.2, 0.3, 0.4) were successfully synthesized by in situ vacuum hot pressing via multi-elements solid solution. The multi-elements solid solution in single-atom thick A layer was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy as well as by energy dispersive X-ray spectroscopy mappings. Effects of doped multi-elements contents on the phase, microstructure, mechanical properties, and high temperature tribological behaviors were studied. Results demonstrated that the Vickers hardness, anisotropic flexural strength, fracture toughness, and tribological properties of Ti–Al–C based MAX ceramics could be remarkably improved by constitution of quasi-high-entropy MAX phase in A layers. Moreover, the strengthening and wear mechanisms were also discussed in detail. This method of multi-element solid solution at A-site provides new way to enhance mechanical properties of other MAX phase ceramics. 相似文献