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Microstructures and Properties of Biomedical Mg-Zn-Sn-Zr Rolled Alloys

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Journal of Wuhan University of Technology(materials science) 2024年第3期39卷 766-773页

作者：周生刚 ZHANG Daxin XU Yang DUAN Jihao LI Tao LIU Junfeng WANG Peng 曹勇 Faculty of material science and Engineering Kunming University of Science and TechnologyKunming 650093China

The as-cast Mg-2.0Zn-1.5Sn-xZr(x=0,0.4,0.6,0.8,1.0 wt%)alloy was rolled with the pressure less than 5%each *** microstructure,mechanical properties,corrosion properties and biocompatibility of the alloy were *** microstructure of the alloy was observed and analyzed by scanning electron microscope,and the tensile test was carried out by universal tensile *** corrosion resistance of the alloy in Hank's solution was studied by hydrogen evolution experiment and electrochemical test,and the biocompatibility of the alloy was tested by L929 *** results show that Mg-2Zn-1.5Sn-xZr alloy has excellent mechanical *** elongation of Mg-2Zn-1.5Sn-xZr alloy decreases with the increase of Zr content,but the tensile strength first increases and then decreases with the increase of Zr *** the Zr content is 0.8 wt%,the maximum tensile strength of the alloy is 235 *** results of hydrogen evolution experiment and electrochemical analysis show that the corrosion resistance of the alloy is the best when the Zr content is 0.8 wt%,and all the five alloys have high *** conclusion,the rolled alloy has good properties and has broad application prospects in the field of biomaterials.

关键词： magnesium alloy corrosion performance mechanical properties biocompatibility

Enhanced visible light absorption of Bi_(2)WO_(6)/SiO_(2) with abundant adsorbed oxygen for the degradation of organic pollutant

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Particuology 2024年第5期88卷 210-217页

作者： Yuanting Wu Xiaoying Wang Wenlong Zhong Shan Zhang School of material science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China

Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural *** by nanosizing the pure Bi_(2)WO_(6)(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO_(2)(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W *** addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O^(2−) in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge ***,the matched photonic bandgap further improves the absorption and utilization of light of the *** this work,we constructs Si–O–W bonds to obtain inverse-opal SiO_(2)/Bi_(2)WO_(6) with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.

关键词： Bi_(2)WO_(6) SiO_(2) inverse-opal structure Photocatalysis Adsorbed oxygen

Wigner function of optical cumulant operator and its dissipation in thermo-entangled state representation

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Chinese Physics B 2024年第6期33卷 205-210页

作者：张科李兰兰范洪义 School of Electronic Engineering Huainan Normal UniversityHuainan 232038China department of material science and Engineering University of Science and Technology of ChinaHefei 230026China

To conveniently calculate the Wigner function of the optical cumulant operator and its dissipation evolution in a thermal environment, in this paper, the thermo-entangled state representation is introduced to derive the general evolution formula of the Wigner function, and its relation to Weyl correspondence is also discussed. The method of integration within the ordered product of operators is essential to our discussion.

关键词： Wigner function optical cumulant operator dissipation evolution thermo-entangled state representation integration within ordered product of operators

The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner

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Research in Astronomy and Astrophysics 2024年第1期24卷 212-222页

作者： Shaoxiong Guo Yan Yang Yanbin Yin Yihu Tang Yang Tian Chao Zhai department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China School of Biomedical Engineering Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China Experiment Center of Engineering and material science University of Science and Technology of ChinaHefei 230026China

With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper ***,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been *** overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current *** must be done while ensuring adequate resolution of the PWM *** employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power *** sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μ***,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive *** device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope.

关键词： instrumentation:adaptive optics instrumentation:spectrographs proper motions reference systems

Urchin-like Na-doped zinc oxide nanoneedles for low-concentration and exclusive VOC detections

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Journal of Advanced Ceramics 2024年第4期13卷 507-517页

作者： Yiwen Zhou Yifan Luo Zichen Zheng Kewei Liu Xiaoxi He Kaidi Wu Marc Debliquy Chao Zhang College of Mechanical Engineering Yangzhou UniversityYangzhou 225127China material science department University of MonsMons 7000Belgium

In the early-stage diagnosis of lung cancer,the low-concentration(<5 ppm)volatile organic compounds(VOCs)are extensively identified to be the biomarkers for breath ***,the urchin-like sodium(Na)-doped zinc oxide(ZnO)nanoneedles were synthesized through a hydrothermal strategy with the addition of different contents of citric *** Na-doped ZnO gas sensor with a 3:1 molar ratio of Na^(+)and citric acid showed outstanding sensing properties with an optimal selectivity to various VOCs(formaldehyde(HCOH),isopropanol,acetone,and ammonia)based on working temperature ***,significantly enhanced sensitivity(21.3@5 ppm)compared with pristine ZnO(~7-fold),low limit of detection(LOD)(298 ppb),robust humidity resistance,and long-term stability of formaldehyde sensing performances were obtained,which can be attributed to the formation of a higher concentration of oxygen vacancies(20.98%)and the active electron ***,the improved sensing mechanism was demonstrated by the exquisite band structure and introduction of the additional acceptor level,which resulted in the narrowed bandgap of ZnO.

关键词： zinc oxide(ZnO) heterovalent ions doping citric acid gas sensor volatile organic compound(VOC)detection lungcancer

Effects of hot deformation and in-situ ZrB2 particle on microstructure and tensile performance of AA7085 composite sheets

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1778-1791页

作者： Jiang-jing Wu Xi-zhou Kai Chuang Guan Yu-tao Zhao School of material science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

To provide a new idea to reduce anisotropy for sheets in the thickness direction by microstructure modification and,mean-while,maintain or even enhance tensile performance,the in-situ ZrB2 particle/AA7085 composite sheets with thicknesses of 1,2,3,and 6 mm were *** as-cast grain size was significantly refined by the heterogeneous nucleus of the ZrB2 *** microstructure results show that severe hot deformation converts as-cast disordered microstructure into a sequential microstructure by crushing the remanent phases and matrix into a fiber *** the solid solution and aging heat treatment,the composite sheets exhibit largely recrystallized grains compared with partially recrystallized grains in the matrix sheets,and weak or even free texture exists in the *** grain size in the composite sheets decreases with the increase in thickness *** the thickness range of 1-3 mm,the composite sheets maintain a similar tensile per-formance as that in matrix sheets,while the strength and ductility in the 6-mm-thick composite sheet are improved.

关键词： Composite sheet Grain structure Texture Dislocation Strengthening

Effect of Bimodal Quasicrystal Phase on the Dynamic Recrystallization of Mg–Zn–Gd Alloy during High-Pressure Torsion

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1128-1134页

作者： Ping Li Shuangwu Xia Junfu Dong Liangwei Dai Zhicheng Luo Kemin Xue School of material science and Engineering Hefei University of TechnologyHefei230009China

The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.

关键词： High-pressure torsion(HPT)-Quasicrystal phase Dynamic recrystallization Particle-stimulated nucleation Orientation relationship

Role of Crystal Seed in Aluminum Hydroxide Crystallization from Ammonia System with Added NH_(4)Al(SO_(4))_(2)·12H_(2)O

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Journal of Wuhan University of Technology(materials science) 2024年第4期39卷 945-953页

作者：王俊凯李来时 LIU Feng WANG Yuzheng 吴玉胜 School of material science and Engineering Shenyang University of TechnologyShenyang 110870China

A method to promote aluminum hydroxide crystal growth through pickling Al(OH)_(3)as seed in the ammonia system was proposed to overcome these *** experimental results show that,under the conditions of pickling time of 15 min,the acid concentration of 10%,the addition of 70 g/L pickling-Al(OH)_(3)seed,and the coarse granular Al(OH)_(3)products(d0.5=85.667)can be *** characterization results show that the phase of the product is gibbsite,consistent with the ***,the steps and ledges can be formed on pickling Al(OH)_(3)seed surface under the ammonia system,effectively promoting crystal *** crystal growth,the roughness of the crystal surface was first increased and then decreased,and the lamellar structure was deposited on the crystal seed *** final particles are approximately round,the surface is compact and *** growth of the product is surface reaction *** addition,the content of the AlO_(6)unit is increased and contributed to Al(OH)_(3)crystal growth.

关键词： reactive crystallization coarse-grained Al(OH)_(3) crystal seed crystal growth process

Polyoxometalates-derived ternary metal oxides electrocatalyst for N_(2) reduction under ambient conditions

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Tungsten 2024年第2期6卷 428-437页

作者： Meng-Le Yang Zhong-Xin Jin Xi-Xian Cao Xin-Ming Wang Hui-Yuan Ma Hai-Jun Pang Gui-Xin Yang The School of material science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150040China

Accelerating the breaking of the nitrogen nonpolar bond(N≡N)is an important factor to improve the effi ciency of the electro-catalytic nitrogen reduction reaction(e-NRR).In this work,polyoxometalates-derived FeMo-based ternary oxide materials MoO_(2)-Mo_(4)O_(11)-FeMoO_(4)@X(abbreviated as MoFeO@X,X represents the synthesis temperature of 650,750 and 850℃)were designed and synthesized for e-NRR under ambient *** scanning electron microscopy images of MoFeO@750 show an ellipsoidal-like structure(0.86×0.6μm).The relatively large specifi c surface area,formation of multiple interfaces,together with the synergistic eff ect of iron and molybdenum bimetals,would make MoFeO@X catalyst more easily absorb and activate N_(2)in the ***,the synthesized MoFeO@750 shows an optimal NH_(3)production rate of 16.57μg·h^(−1)·mg cat.^(−1)and Faradaic effi ciency of 12.33%at−0.3 V versus reversible hydrogen electrode(ν***),with outstanding electrochemical and structural stability.

关键词： Polyoxometalates Electrocatalytic nitrogen reduction reaction Ternary oxide Electrocatalyst