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Rare Metals 2021年第3期40卷 607-615页

作者： sheng-nan zhang Li-Na Jia Yue-Ling Guo Bin Kong Feng-Xiang zhang Hu zhang School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The microstructure and oxidation behavior of directionally solidified(DS) Nb-15 Si-24 Ti-4 Cr-2 Al-2 Hf alloys with separate vanadium,tantalum,tungsten and zirconium additions were investigated by X-ray diffraction(XRD),electron probe microanalyzer(EPMA) equipped with wave-dispersive spectroscopy(WDS),scanning electron microscopy(SEM) and transmission electron microscopy(TEM) equipped with an energy-dispersive spectroscopy(EDS).Results show that the five alloys are all composed of primary(Nb,Ti) solid solution((Nb,Ti)ss)phase and eutectic(Nb,Ti)ss/(Nb,Ti)_(5) S_(3) *** oxidation at 1250℃ for 100 h in air,the surfaces of the five alloys are covered by the oxides of Nb_(2)O_(5),TiNb_(2) O_(7),Ti_(2) Nb10O29,TiO_(2) and amorphous SiO_(2).It is found that the alloying elements of V and W are detrimental for oxidation resistance and the addition of Ta has no obvious *** addition obviously benefits the oxidation resistance at high temperature,by decreasing the weight gain from 242.75 to184.83 mg·cm^(-2).The oxidation mechanism of Nb-Sibased alloys and the effects of different alloying elements on the oxidation resistance of Nb-Si-based alloys were discussed.

关键词： Nb-Si-based alloys Directional solidification Microstructure Oxidation

Doping effect on thermoelectric properties of nonstoichiometric AgSbTe_2 compounds

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International Journal of Minerals,Metallurgy and Materials 2011年第3期18卷 352-356页

作者： sheng-nan zhang Guang-yu Jiang Tie-jun Zhu Xin-bing Zhao sheng-hui Yang State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Northwest Institute of Non-Ferrous Metal Research Xi＇an 710016 China

Nonstoichiometric ternary thermoelectric materials Ag0.84Sb1.15M0.01Te2.16 （M=Ce, Yb, Cu） were prepared by a direct melt-quench and hot press process. The carrier concentration of all the samples increased after doping. Thermoelectric properties, namely electrical con-ductivity, Seebeck coefficient, and thermal conductivity, were measured from 300 to 673 K. The phase transition occurring at about 418 K representing the phase transition from b-Ag2Te to a-Ag2Te influenced the electrical transport properties. The electrical conductivities of Ce and Yb doped samples increased after doping from 1.9×104 to 2.5×104 and 2.3×104 S·m-1, respectively, at 673 K. Also, at room temperature, the Seebeck coefficient of the Ce doped sample relatively increased corresponding to the high carrier concentration due to the changes in the band structure. However, all the thermal conductivities increased after doping at low temperature. Because of the higher thermal conductivity, the dimensionless figure of merit ZT of these doped samples has not been improved.

关键词： thermoelectric materials rare earth elements doping silver antimony telluride

Additive-aided electrochemical deposition of bismuth telluride in a basic electrolyte

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International Journal of Minerals,Metallurgy and Materials 2010年第4期17卷 489-493页

作者： Wu-jun Qiu sheng-nan zhang Tie-jun Zhu Xin-bing Zhao State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China

A new basic electrolyte with two cationic plating additives, polydiaminourea and polyaminosulfone, was investigated for the electrochemical deposition of the bismuth telluride film on a nickel-plated copper foil. Tellurium starts to deposit at a higher potential （-0.35 V） than bismuth （-0.5 V） in this electrolyte. The tellurium-to-bismuth ratio increases while the deposition potential declines from -1 to -1.25 V, indicating a kinetically quicker bismuth deposition at higher potentials. The as-deposited film features good adhesion to the substrate and smooth morphology, and has a nearly amorphous crystal structure disclosed by X-ray diffraction patterns.

关键词： thin films thermoelectric materials electrochemical deposition bismuth telluride basic electrolyte

Optimization of sintering parameters for fabrication of Ag-sheathed FeSe superconducting wires

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Rare Metals 2018年第5期37卷 433-438页

作者： Jian-Qing Feng sheng-nan zhang Ji-Xing Liu Bo-Tao Shao Cheng-Shan Li Ming Liang Ping-Xiang zhang Superconducting Materials Research Center Northwest Institute for Non-Ferrous Metal Research School of Materials Science and Engineering Northeastern University School of Materials Science and Engineering Xi'an University of Technology

Ag-sheathed Fe1.05Se superconducting wires were fabricated with ex-situ powder in tube （PIT） process. Fe and Se powders with molar ratio of 1.05 were firstly mixed and sintered under 600 ℃ for 12 h to form precursor powders. Owing to the complex Fe-Se binary phase diagram, both superconducting tetragonal FeSe and nonsuperconducting hexagonal FeSe could be formed simultaneously during sintering. Aiming at the reduction of hexagonal FeSe phase content and higher superconducting phase volume, the influences of key parameters, including sintering time, cooling rate and heating rate, on the phase composition of sintered wires were systematically studied. Optimal sintering parameters are obtained, and the maximum tetragonal FeSe phase content of ~ 97% is achieved. Meanwhile, the effects of packing density of precursor powders on the phase composition of final wires were also discussed. Owing to the shorter length of diffusion path, more tetragonal FeSe was formed with higher packing density. The superconducting transition signal with critical temperature of ~ 7.5 K was obtained, which proved the effectiveness of our optimal sintering process.

关键词： Superconductors FeSe Powder in tube Phase composition Superconducting transition

Enhanced thermoelectric properties of Co_(1-x-y)Ni_(x+y)Sb_(3-x)Sn_x materials

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 240-244页

作者： Hong-quan Liu sheng-nan zhang Tie-jun Zhu Xin-bing Zhao Yi-jie Gu Hong-zhi Cui College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266510 China State Key Laboratory of Silicon Materials Development of Materials Science and Engineering Zhejiang University Hangzhou 310027 China

Co1-x-yNix＋ySb3-xSnx polycrystals were fabricated by vacuum melting combined with hot-press sintering. The effect of alloying on the thermoelectric properties of unfilled skutterudite CO1-xNixSb3-xSnx was investigated. A leap of electrical conductivity from the Co0.93Ni0.07Sb2.93Sn0.07 sample to the Co0.88Ni0.12Sb288Sn0.12 sample occurs during the measurement of electrical conductivity, indicating the adjustment of band structure by proper alloying. The results show that alloying enhances the power factor of the materials. On the basis of alloying, the thermoelectric properties of ***.12 are improved by Ni-doping. The thermal conductivities of Ni-doping samples have no reduction, but their power factors have obvious enhancement. The power factor of Co0.81Ni0.09Sb2.88Sn0.12 reaches 3.0 mW-m-1·K-2 by Ni doping. The dimensionless thermoelectric figure of merit reaches 0.55 at 773 K for the unfilled Co0.81Ni0.19 Sb2.88Sn0.12,

关键词： thermoelectric material polycrystals skuttemdites alloying thermoelectric properties clopping

Association Between Rectus Abdominis Denervation and Ventilation Dysfunction in Patients with Amyotrophic Lateral Sclerosis

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Chinese Medical Journal 2016年第17期129卷 2063-2066页

作者： Hua-Gang zhang Shuo zhang Ying-sheng Xu nan zhang Dong-sheng Fan Department of Neurology Peking University Third Hospital Beijing 100191 China

Background： Spontaneous potentials in electromyography （EMG） ofparaspinal muscles are associated with diaphragm denervation and, therefore, poor respiratory timction in amyotrophic lateral sclerosis （ALS） is understandable. EMG changes in the rectus abdominis （RA） display an effect similar to those in paraspinal muscles with respect to the function of lower motor neurons in the thoracic spinal cord. The RA denervation was examined to determine its association with ventilation dysfunction in ALS. Methods： We collected the clinical data of 128 patients with sporadic ALS in Department of Neurology of Peking University Third Hospital from 2009 to 2013. EMG, Revised ALS Functional Rating Scale （ALSFRS-R） and forced vital capacity （FVC） were perIbrmed in all patients and the differences in the EMG changes in RA between those with and without FVC 〉 80% were analysed. Results： The mean FVC value was 83.4% ~ 17.1% （range： 45%-I 31%） of the predicted value. A total of 79 patients displayed FVC _〉80%, and 49 patients displayed FVC 〈80%, Compared with the patients displaying a normal FVC （60/79, 75.9%）, spontaneous activity in RA was significantly different among those patients displaying an FVC 〈80% （47/49, 95.9%）. In addition, spontaneous potentials in RA were more frequently detected in patients exhibiting dyspnea （32/33, 97.0%） than in patients without dyspnea （75/95, 78.9%）. Conclusion： Spontaneous potentials in RA are associated with ventilation dysfunction and dyspnea in ALS patients.

关键词： Denervation Dyspnea Forced Vital Capacity Rectus Abdominis Ventilation Dysfunction

Alloy strategy to synthesize Pt-early transition metal oxide interfacial catalysts

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nano Research 2024年第4期17卷 3390-3397页

作者： Shi-Long Xu Hang nan Wanqun zhang Yue Lin sheng-Qi Chu Hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Metal oxide supported metal catalysts show promising catalytic performance in many industry-relevant ***,the enhancement of performance is often limited by the insufficient metal/metal oxide *** this work,we demonstrate a general synthesis of Pt-early transition metal oxide(Pt-MO_(x),M=Ti,Zr,V,and Y)catalysts with rich interfacial sites,which is based on the air-induced surface segregation and oxidation of M in the supported Pt-M alloy *** characterizations verify the dynamic structural response of Pt-M alloy catalysts to air and the formation of Pt-MO_(x) catalysts with abundant interfacial *** prepared Pt-TiO_(x) interfacial catalysts exhibit improved performance in hydrogenation reactions of benzaldehyde,nitrobenzene,styrene,and furfural,as a result of the heterolytic dissociation of H_(2) at Pt-metal oxide interfacial sites.

关键词： Pt-early transition metal oxide interfacial catalyst alloy oxidation strategy interfacial sites hydrogenation reactions heterolytic dissociation

The relationship among amyloid-βdeposition,sphingomyelin level,and the expression and function of P-glycoprotein in Alzheimer’s disease pathological process

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Neural Regeneration Research 2023年第6期18卷 1300-1307页

作者： Zi-Kang Xing Li-Sha Du Xin Fang Heng Liang sheng-nan zhang Lei Shi Chun-Xiang Kuang Tian-Xiong Han Qing Yang State Key Laboratory of Genetic Engineering School of Life SciencesShanghai Engineering Research Center of Industrial MicroorganismsFudan UniversityShanghaiChina Shanghai Key Lab of Chemical Assessment and Sustainability School of Chemical Science and EngineeringTongji UniversityShanghaiChina Department of Traditional Chinese Medicine Tenth People’s Hospital of Tongji UniversityShanghaiChina

In Alzheimer’s disease,the transporter P-glycoprotein is responsible for the clearance of amyloid-βin the ***-βcorrelates with the sphingomyelin metabolism,and sphingomyelin participates in the regulation of *** amyloid cascade hypothesis describes amyloid-βas the central cause of Alzheimer’s disease *** understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-βand their potential association in the pathological process of Alzheimer’s disease is ***,we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable *** functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of *** sphingomyelin levels,increased ceramide levels,and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type *** results were observed in the Alzheimer’s disease mouse model induced by intracerebroventricular injection of amyloid-β1-42 and human cerebral microvascular endothelial cells treated with amyloid-β*** human cerebral microvascular endothelial cells,neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-β1-42 *** sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ***,these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide *** studies may serve as new pursuits for the development of anti-Alzheimer’s disease drugs.

关键词： Alzheimer’s disease amyloid-β APP/PS1 mice ceramide ezrin-radixin-moesin human cerebral microvascular endothelial cells neutral sphingomyelinase 1 P-glycoprotein sphingomyelin synthase sphingomyelin

Fully sprayed MXene-based high-performance flexible piezoresistive sensor for image recognition

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nano Materials Science 2024年第1期6卷 77-85页

作者： Zhi-Dong zhang Xue-Feng Zhao Qing-Chao zhang Jie Liang Hui-nan zhang Tian-sheng zhang Chen-Yang Xue Key Laboratory of Instrumentation Science&Dynamic Measurement of Ministry of Education North University of ChinaTaiyuan030051People's Republic of China State Key Laboratory of ASIC and System Shanghai Institute of Intelligent Electronics&SystemsSchool of MicroelectronicsFudan UniversityShanghai200433People's Republic of China Shanxi Hosipital of Acupuncture and Moxibustion Taiyuan030006People's Republic of China

High-performance flexible pressure sensors provide comprehensive tactile perception and are applied in human activity monitoring,soft robotics,medical treatment,and human-computer ***,these flexible pressure sensors require extensive nano-architectural design and complicated manufacturing and are ***,a highly sensitive,flexible piezoresistive tactile sensor is designed and fabricated,consisting of three main parts:the randomly distributed microstructure on T-ZnOw/PDMS film as a top substrate,multilayer Ti_(3)C_(2)-MXene film as an intermediate conductive filler,and the few-layer Ti_(3)C_(2)-MXene nanosheetbased interdigital electrodes as the bottom *** MXene-based piezoresistive sensor with randomly distributed microstructure exhibits a high sensitivity over a broad pressure range(less than 10 kPa for 175 kPa^(-1))and possesses an out-standing permanence of up to 5000 ***,a 16-pixel sensor array is designed,and its potential applications in visualizing pressure distribution and an example of tactile feedback are *** fully sprayed MXene-based pressure sensor,with high sensitivity and excellent durability,can be widely used in,electronic skin,intelligent robots,and many other emerging technologies.

关键词： Piezoresistive sensor Ti_(3)C_(2)-MXene T-ZnOw/PDMS film Randomly distributed microstructure

Enhanced quality of Al2O3/SiC gate stack via microwave plasma annealing

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Rare Metals 2024年第10期43卷 5362-5371页

作者： nan-nan You Xin-Yu Liu Qian zhang Zhen Wang Jia-Yi Wang Yang Xu Xiu-Yan Li Yu-Zheng Guo sheng-Kai Wang High-Frequency High-Voltage Device and Integrated Circuits R&D Center Institute of Microelectronics of the Chinese Academy of Sciences School of Integrated Circuits University of Chinese Academy of Sciences School of Electrical Engineering and Automation Wuhan University Department of Micro/nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong University

The high-quality gate dielectric on silicon carbide （SiC） surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors（MOSFETs）.This research employs microwave plasma annealing （MPA） to obtain high-quality Al2O3/SiC gate *** designing MPA atmosphere and optimizing the plasma power,the SiC MOS capacitor with a Al2O3dielectric film shows the enhanced *** interface state density is reduced by 1 order of magnitude to 6×1011cm-2·eV-1,the breakdown electric field is increased,and the voltage shift is effectively suppressed Besides,the mechanism of MPA process is discussed in terms of the thermal effect and reactant species.X-ray photoelectron spectroscopy （XPS） results unveil oxygen plasma plays the main *** plasma power during the MPA process results in defect repairs of the firstneighbor Al-O bonding and partial removal of Al-O-H bond from the interface *** study demonstrates that MPA process is an effective option to realize highquality dielectric and interface on SiC.

关键词： Al2O3 Defect repairs Metal–oxide–semiconductor Microwave plasma annealing Silicon carbide X-ray photoelectron spectroscopy