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Second harmonic magnetoacoustic responses of magnetic nanoparticles in magnetoacoustic tomography with magnetic induction

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Chinese Physics B 2020年第3期29卷 259-264页

作者： Gepu Guo Ya gao Yuzhi Li qingyu ma juan Tu Dong Zhang School of Physics and Technology Nanjing Normal UniversityNanjing 210023China Institute of Acoustics Nanjing UniversityNanjing 210093China

Due to the unique magnetic, mechanical and thermal properties, magnetic nanoparticles(MNPs) have comprehensive applications as the contrast and therapeutic agents in biomedical imaging and magnetic hyperthermia. The linear and nonlinear magnetoacoustic responses determined by the magnetic properties of MNPs have attracted more and more attention in biomedical engineering. By considering the relaxation time of MNPs, we derive the formulae of second harmonic magnetoacoustic responses(2H-maRs) for a cylindrical MNP solution model based on the mechanical oscillations of MNPs in magnetoacoustic tomography with magnetic induction(maT-MI). It is proved that only the second harmonic magnetoacoustic oscillations can be generated by MNPs under an alternating magnetic excitation. The acoustic pressure of the 2H-maR is proportional to the square of the magnetic field intensity and exhibits a linear increase with the concentration of MNPs. Numerical simulations of the 2H-maR are confirmed by the experimental measurements for various magnetic field intensities and solution concentrations using a laser vibrometer. The favorable results demonstrate the feasibility of the harmonic measurements without the fundamental interference of the electromagnetic excitation, and suggest a new harmonic imaging strategy of maT-MI for MNPs with enhanced spatial resolution and improved signal-to-noise ratio in biomedical applications.

关键词： magnetoacoustic tomography with magnetic induction second harmonic magnetoacoustic responses magnetic nanoparticles magnetic force mechanical oscillations

Some selected topics on structural safety

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Acta Mechanica Sinica 2023年第4期39卷 1-2页

作者： juan ma Wei gao Research Centre of Applied Mechanics School of Mechano-Electronic EngineeringXidian UniversityXi’an710071China Centre for Infrastructure Engineering and Safety(CIES) School of Civil and Environmental EngineeringThe University of New South WalesSydneyNSW2052Australia

Structural safety and reliability play an extremely important role in modern life and have been one of the hot research topics in the past *** to the complexity of the problem in nature,extensive studies on structural safety are still highly *** thematic issue of Acta Mechanica Sinica on structural safety contains nine papers addressing a wide variety of research areas ranging from the development of the fundamental numerical method for structural analysis to the reliability assessment of structures concerned by different disciplines.

关键词： structural concerned reliability

Phytate-Coordination Triggered Enrichment of Surface NiOOH Species on Nickel Foam for Efficient Urea Electrooxidation

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Chinese Journal of Structural Chemistry 2022年第7期41卷 35-39页

作者： Jiayuan Li Yuefei Li qingyu Xue Yuchi gao Yuanyuan ma Key Laboratory of Special Functional and Smart Polymer materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi'an 710072China

Nickel(Ni)-based materials are promising electrocatalysts for the urea electrooxidation reaction, as the in situ formed NiOOH species on their surface during operation are catalytically active sites. In this work, phytate-coordinated Ni foam(PA-NF)is shown to deliver a high catalytic performance, with a potential as low as 1.38 V at 10m A/cm2, a Tafel slope as low as 64.1 mV/dec, and superior catalytic stability. Characterizations revealed that such a high performance was ascribed to the kinetic acceleration of surface reconstruction and the enriched NiOOH active species on the PA-NF surface owing to PA-coordination induced upshift of d-band center of Ni ***, a novel and simple strategy is provided for designing the efficient as well as universal Ni-based catalyst for the electrooxidation of urea, which can also be extended to other transition-metal-based systems.

关键词： phytates surface coordination urea electrooxidation reaction electrocatalysis

Effects of Y_2O_3 on the microstructure and wear resistance of cobalt-based alloy coatings deposited by plasma transferred arc process

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Rare Metals 2007年第2期26卷 103-109页

作者： HOU qingyu HUANG Zhenyi gao Jiasheng Anhui Key Laboratory of Metal materials and Processing School of Materials Science and Engineering Anhui University of Technology Ma＇anshan 243002 China

Cobalt-based alloys with different Y2O3 contents were deposited on Q235A-carbon steel using plasma transferred arc （PTA） welding machine. The effect of Y2O3 on the microstructure and wear resistance properties of the cobait-based alloys were investigated using an optical microscope, a scanning electron microscope （SEM）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. It was found that a cobalt-based solid solution with a face-centered cubic crystal structure was presented accompanied by the secondary phase M7C3 with a hexagonal crystal structure in the Y2O3-free cobalt-based alloy coating. Several stacking faults exist in the cobalt-based solid solution. The addition of Y2O3 leads to the existence of the Y2O3 phase in the Y2O3-modified coatings. Though stacking fault exists in the Y2O3-modified coatings, its density increases. The addition of Y2O3 can refine the microstructure and can increase the wear resistance properties when its contents are less than or equal to 0.8 wt.%. However, further increase of its contents will lead to the agglomeration of undissolved Y2O3 particles at the γ-Co grain boundary, and will lead to a coarse microstructure and lower wear resistance properties.

关键词： cobalt-based alloy plasma transferred arc (PTA) Y2O3 microstructure wear resistance

Weak-focused acoustic vortex generated by a focused ring array of planar transducers and its application in large-scale rotational object manipulation

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Chinese Physics B 2021年第4期30卷 319-327页

作者： Yuzhi Li Peixia Li Ning Ding Gepu Guo qingyu ma juan Tu Dong Zhang School of Computer and Electronic Information/School of Artificial Intelligence Nanjing Normal UniversityNanjing 210023China Institute of Acoustics Nanjing UniversityNanjing 210093China

Contactless manipulation of multi-scale objects using the acoustic vortex(AV) tweezers offers tremendous perspectives in biomedical ***,it is still hindered by the weak acoustic radiation force(ARF) and torque(ART)around the vortex *** introducing the elevation angle to the planar transducers of an N-element ring array,the weakfocused acoustic vortex(WFAV) composed of a main-AV and N paraxial-AVs is constructed to conduct a large-scale object *** from the traditional focused AV(FAV) generated by a ring array of concave spherical transducers,a much larger focal region of the WFAV is generated by the main lobes of the planar transducers with the size inversely associated with the elevation *** the pressure simulation of the acoustic field,the capability of the rotational object driving in the focal plane for the WFAV is analyzed using the ARF and the ART exerted on an elastic ball based on acoustic *** the experimental system built in water,the generation of the WFAV is verified by the scanning measurements of the acoustic field and the capability of object manipulation is also analyzed by the rotational trapping of floating particles in the focal *** favorable results demonstrate the feasibility of large-scale rotational manipulation of objects with a strengthened ART and a reduced acousto-thermal damage to biological tissues,showing a promising prospect for potential applications in clinical practice.

关键词： acoustic vortex weak-focused large-scale object manipulation acoustic scatter acoustic radiation force

The TaFIM1 gene mediates wheat resistance against Puccinia striiformis f. sp. tritici and responds to abiotic stress

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Journal of Integrative Agriculture 2021年第7期20卷 1849-1857页

作者： SHI Bei-bei WANG juan gao Hai-feng ZHANG Xiao-juan WANG Yang ma Qing State Key Laboratory of Crop Stress Biology for Arid Areas Northwest A&F UniversityYangling 712100P.R.China School of Life Science Shanxi Datong UniversityDatong 037009P.R.China Institute of Plant Protection Xinjiang Academy of Agricultural Sciences/Key Laboratory of Integrated Pest Management on Crop in Northwestern OasisMinistry of Agriculture and Rural AffairsUrumqi 830091P.R.China

Fimbrin, a regulator of actin cytoskeletal dynamics that participates in numerous physiological and biochemical processes, controls multiple developmental processes in a variety of tissues and cell types. However, the role of fimbrin in pathogen defense of wheat and the mechanisms have not been well studied. Here, we investigated that the expression of TaFIM1 gene of wheat was significantly induced in response to avirulent race of Puccinia striiformis f. sp. tritici(Pst) and silencing of TaFIM1 by virus-induced gene silencing method. The results show that silencing of TaFIM1 resulted in a reduction of resistance against the stripe rust indicated by both phenotypes and a histological examination of Pst growth. Additionally, the expression level of Ta FIM1 gene was up-regulated under abiotic stresses. These findings suggest that Ta FIM1 functions as a positive regulator of pathogen resistance of wheat plants and response to abiotic stress. Our work may show new light on understanding the roles of fimbrin in wheat.

关键词： wheat Puccinia striiformis f.sp.tritici fimbrin disease resistance abiotic stress

Beam alignments based on the spectrum decomposition of orbital angular momentums for acoustic-vortex communications

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Chinese Physics B 2022年第12期31卷 296-304页

作者： Gepu Guo Xinjia Li Qingdong Wang Yuzhi Li qingyu ma juan Tu Dong Zhang School of Computer and Electronic Information Nanjing Normal UniversityNanjing 210023China Haiying Enterprise Group Co. Ltd.Wuxi 214061China College of Ocean Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Institute of Acoustics Nanjing UniversityNanjing 210093China

Given the enhanced channel capacity of wave chirality,acoustic communications based on the orbital angular momentum(OAM)of acoustic-vortex(AV)beams are of significant interest for underwater data ***,the stringent beam alignment is required for the coaxial arrangement of transceiver arrays to ensure the accuracy and reliability of OAM *** avoid the required multiple measurements of the traditional orthogonality based algorithm,the beam alignment algorithm based on the OAM spectrum decomposition is proposed for AV communications by using simplified *** studies of the single-OAM and OAM-multiplexed AV beams show that the error of the OAM spectrum increases with the translation distance and the deflection angle of the transceiver *** achieve an ideal arrangement,two methods of the single-array translation alignment and the dual-array deflection alignment are developed based on the least standard deviation of the OAM spectrum(SD-OAM).By decreasing the SD-OAM towards zero using transceiver arrays of 16 transmitters and 16 receivers,accurate beam alignments are accomplished by multiple adjustments in three *** proposed method is also demonstrated by experimental measurements of the OAM dispersion and the SD-OAM for misaligned *** results demonstrate the feasibility of the rapid beam alignment based on the OAM spectrum decomposition by using simplified transceiver ring-arrays,and suggest more application potentials for acoustic communications.

关键词： acoustic-vortex beam beam alignment orbital angular momentum(OAM)spectrum least standard deviation acoustic communication

Phase-Dislocation-Mediated High-Dimensional Fractional Acoustic-Vortex Communication

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Research 2024年第3期2023卷 575-584页

作者： Ruijie Cao Gepu Guo Wei Yue Yang Huang Xinpeng Li Chengzhi Kai Yuzhi Li juan Tu Dong Zhang Peng Xi qingyu ma School of Computer and Electronic Information Nanjing Normal UniversityNanjing 210023China Department of Biomedical Engineering College of Future TechnologyPeking UniversityBeijing 100871China nstitute of Acoustics Nanjing UniversityNanjng 210093China National Biomedical Imaging Center Peking UniversityBeijing 100871China

With unlimited topological modes in mathematics,the fractional orbital angular momentum(FOAM)demonstrates the potential to infinitely increase the channel capacity in acoustic-vortex(AV)***,the accuracy and stability of FOAM recognition are still limited by the nonorthogonality and poor anti-interference of fractional AV *** popular machine learning,widely used in optics based on large datasets of images,does not work in acoustics because of the huge engineering of the 2-dimensional point-by-point ***,we report a strategy of phase-dislocation-mediated high-dimensional fractional AV communication based on pair-FOAM multiplexing,circular sparse sampling,and machine *** unique phase dislocation corresponding to the topological charge provides important physical guidance to recognize FOAMs and reduce sampling points from theory to practice.A straightforward convolutional neural network considering turbulence and misalignment is further constructed to achieve the stable and accurate communication without involving experimental *** experimentally present that the 32-point dual-ring sampling can realize the 10-bit information transmission in a limited topological charge scope from±0.6 to±2.4 with the FOAM resolution of 0.2,which greatly reduce the divergence in AV *** infinitely expanded channel capacity is further verified by the improved FOAM resolution of *** with other milestone works,our strategy reaches 3-fold OAM utilization,4-fold information level,and 5-fold OAM *** of the extra advantages of high dimension,high speed,and low divergence,this technology may shed light on the next-generation AV communication.

关键词： infinitely topological fractional

Effects of basicity and MgO content on the viscosity of the SiO_2-CaO-MgO-9wt%Al_2O_3 slag system

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International Journal of Minerals,Metallurgy and materials 2014年第4期21卷 353-362页

作者： Yun-ming gao Shao-bo Wang Chuan Hong Xiu-juan ma Fu Yang Key Laboratory for Ferrous Metallurgy and Resources Utilization of the Ministry of Education Wuhan University of Science and Technology

The effects of basicity and MgO content on the viscosity of SiO2-CaO-MgO-9wt%Al2O3 slags with basicity from 0.4 to 1.0 and MgO content from 13wt%to 19wt%were investigated using the rotating cylinder method. A correlation between the viscosity and the slag structure was determined by Fourier transform infrared （FTIR） spectroscopy. It is indicated that the complex network structure of the slag melt is depolymerized into simpler network units with increasing basicity or MgO content, resulting in a continuous decrease in viscosity of the slag. The viscosity is strongly dependent on the combined action of basic oxide components in the slag. Under the present experimental conditions, increasing the basicity is found to be more effective than increasing the MgO content in decreasing the viscosity of the slag. At higher temperatures, the increase of basicity or MgO content does not appreciably decrease the viscosity of the slag, as it does at lower tem-peratures. The calculated activation energy of viscous flow is between 154 and 200 kJ＆#183;mol-1, which decreases with an increase in basicity from 0.4 to 1.0 at a fixed MgO content in the range of 13wt%to 19wt%.

关键词： slags viscosity basicity magnesia activation energy Fourier transform infrared spectroscopy