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Tuning spin reorientation in Er1–xYxFeO3 single crystal family

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Frontiers of physics 2019年第1期14卷 105-110页

作者： Ning Yuan Ru-Bin Li You-Shuang Yu Zheng-Jie Feng Bao-Juan Kang shi-yi zhuo Jun-yi Ge Jin-Cang Zhang shi-Xun Cao Department of Physics International Center of Quantum and Molecular Structures Shanghai University Shanghai 200444 China Materials Genome Institute Shanghai University Shanghai 200444 China Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

A temperature-induced spin reorientation transition between Г4 (Gx, Ay, Fz) and Г2 (Fx, Cy, Gz) has been studied in the family of Er1–xYxFeO3 (x = 0, 0.25, 0.5, 0.75, 1) single crystals. By doping nonmagnetic Y3+, we tuned the spin reorientation temperature to low temperature with increasing x. Moreover, the typical compensation point and spin flip transition of ErFeO3 also decreases with doping, and disappears above x = 0.75. We also report the Rietveld refinements and Raman spectroscopy of Er1–xYxFeO3, where some Raman peaks are shifted to low frequency with increasing doping. Our results shed light on the understanding of the interaction between two magnetic sub-lattices of rare earth (R3+) and iron (Fe3+) ions, and will also contribute to the materials design and potential applications.

关键词： Er1–xYxFeO3 single crystal growth magnetic measurements

Improving model performance in mapping cropland soil organic matter using time-series remote sensing data

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Journal of Integrative Agriculture 2024年第8期23卷 2820-2841页

作者： Xianglin Zhang Jie Xue Songchao Chen Zhiqing zhuo Zheng Wang Xueyao Chen yi Xiao Zhou shi Institute of Applied Remote Sensing and Information Technology College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China Department of Land Management Zhejiang UniversityHangzhou 310058China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311215China Institute of Digital Agriculture Zhejiang Academy of Agricultural SciencesHangzhou 310021China Key Laboratory of Spectroscopy Sensing Ministry of Agriculture and Rural AffairsHangzhou 310058China

Faced with increasing global soil degradation,spatially explicit data on cropland soil organic matter(SOM)provides crucial data for soil carbon pool accounting,cropland quality assessment and the formulation of effective management *** a spatial information prediction technique,digital soil mapping(DSM)has been widely used to spatially map soil information at different ***,the accuracy of digital SOM maps for cropland is typically lower than for other land cover types due to the inherent difficulty in precisely quantifying human *** overcome this limitation,this study systematically assessed a framework of“information extractionfeature selection-model averaging”for improving model performance in mapping cropland SOM using 462 cropland soil samples collected in Guangzhou,China in *** results showed that using the framework of dynamic information extraction,feature selection and model averaging could efficiently improve the accuracy of the final predictions(R^(2):0.48 to 0.53)without having obviously negative impacts on *** the dynamic information of the environment was an efficient way to generate covariates that are linearly and nonlinearly related to SOM,which improved the R^(2)of random forest from 0.44 to 0.48 and the R^(2)of extreme gradient boosting from 0.37to *** recursive feature selection(FRFS)is recommended when there are relatively few environmental covariates(500).The Granger-Ramanathan model averaging approach could improve the prediction accuracy and average *** the structures of initial prediction models are similar,increasing in the number of averaging models did not have significantly positive effects on the final *** the advantages of these selected strategies over information extraction,feature selection and model averaging have a great potential for high-accuracy soil mapping

关键词： cropland soil organic matter digital soil mapping machine learning feature selection model averaging

A highly sensitive multiple-mode optical thermometer designed in Eu^(2+/3+)and Li^(+)co-doped polymorphism compound LaSc_(3)(BO_(3))_(4)

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Journal of Advanced Ceramics 2024年第6期13卷 821-833页

作者： Nan Yang zhuo Li Tingxia Zhou Ziwang Zhang Wen shi Yexiang Tong Jianxin shi School of Chemistry IGCMESun Yat-sen UniversityGuangzhou 510006China MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry IGCMEThe Key Lab of Low-Carbon Chemistry&Energy Conservation of Guangdong ProvinceSun Yat-sen UniversityGuangzhou 510006China

Noncontact optical thermometers have attracted widespread attention,but existing problems such as single-mode and low-sensitivity thermometers still urgently need to be ***,a novel multiple-mode thermometer was designed for the polymorphism LaSc_(3)(BO_(3))_(4):Eu^(2+/3+),Li^(+).X-ray diffraction(XRD)patterns revealed a slight transition betweenα-andβ-phases with the concentrations of the dopants,which is further proved by structure refinements and first-principles *** coexistence of Eu^(2+)and Eu^(3+)in the phosphors and their relative percentages were confirmed by X-ray absorption near-edge structure(XANES)*** from appropriate emissions from Eu^(2+)and Eu^(3+)without obvious energy transfer and their opposite changing trends with temperatures under 307 nm excitation,a triple-mode optical thermometer is obtained for this material within the temperature range of 150–450 *** highest sensitivities of 27.65,14.05,and 7.68%·K^(−1)are achieved based on two fluorescence intensity ratio(FIR)modes of Eu^(2+)and Eu^(3+)(5d–4f/^(5)D_(0)–^(7)F_(2,4))and the fluorescence lifetime(FL)mode of Eu^(2+),*** the best of our knowledge,the former is almost the highest in Eu^(2+)and Eu^(3+)co-doped *** results indicate that this material may be used as an excellent multiple-mode optical thermometer.

关键词： phase transition europium(Eu)ions multiple-mode optical thermometer thermal quenching properties fluorescence intensity ratio(FIR) fluorescence lifetime(FL)

Non-synchronous vibration of rotor blade in a six-stage transonic compressor

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Chinese Journal of Aeronautics 2024年第8期37卷 36-48页

作者： Ronghui CHENG zhuo WANG Huawei YU Lin DU yi ZHANG Xiaofeng SUN Aeroengine Research Institute Beihang UniversityBeijing 102206China School of Energy and Power Engineering Beihang UniversityBeijing 102206China

This paper presents an experimental study on the Non-Synchronous Vibration(NSV)in a six-stage transonic *** first part of the paper describes the NSV phenomenon of Rotor 1,which occurs when both Stator 1(S1)and Stator 2(S2)or S1 only are *** measurements and analysis are carried out for the former case through the unsteady wall pressure and the Blade Strain(BS).The spinning mode theory used in the rotor/stator interaction noise is employed to explain the relation between the circumferential wave number of the aerodynamic disturbance and the Nodal Diameter(ND)of the blade *** variations of the vibration amplitudes of different blades and the Inter-Blade Phase Angles(IBPAs)at different moments suggest that the evolution of NSV is a highly nonuniform phenomenon along the circumferential *** addition,the difference between the wall-pressure spectra generated by the NSV and the classic flutter has been *** the second part,the variations of aerodynamic loading due to the adjustment of the staggers of the Inlet Guide Vane(IGV),S1 and S2 have been *** is found that closing S1 only can result in a great fluctuation to the performance of the front stages,which might be detrimental to the flow organization and increase the risk of *** contrast,the effect of closing S2 only on the performance of the first two stages appears to be slighter relatively.

关键词： Transonic compressor Non-synchronous vibration Modal analysis Aerodynamic loading Nodal diameter

Buckling Optimization of Curved Grid Stiffeners through the Level Set Based Density Method

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 711-733页

作者： zhuo Huang Ye Tian yifan Zhang Tielin shi Qi Xia State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

Stiffened structures have great potential for improvingmechanical performance,and the study of their stability is of great *** this paper,the optimization of the critical buckling load factor for curved grid stiffeners is solved by using the level set based density method,where the shape and cross section(including thickness and width)of the stiffeners can be optimized *** grid stiffeners are a combination ofmany single stiffenerswhich are projected by the corresponding level set *** thickness and width of each stiffener are designed to be independent variables in the projection applied to each level set ***,the path of each single stiffener is described by the zero iso-contour of the level set *** the single stiffeners are combined together by using the p-norm method to obtain the stiffener *** proposed method is validated by several numerical examples to optimize the critical buckling load factor.

关键词： Stiffener buckling optimization shape and cross section level set based density

A fuse-based DC circuit breaker with vacuum interrupter enhanced by an external transverse magnetic field

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High Voltage 2024年第3期9卷 710-720页

作者： Yu Xiao yi Wu yifei Wu Fei Yang Mingzhe Rong zhuo Yang State Key Laboratory of Electrical Insulation and Power Equipment School of Electric EngineeringXi'an Jiaotong UniversityXi'anChina State Grid Shaanxi Electric Power Company Limited Xi'anChina

Due to the increasing power system capacity,the interruption of large fault currents has gradually become a major challenge in power *** the moment,such currents are interrupted mainly via circuit breakers based on the method of active current ***,these types of circuit breakers tend to be costly and *** possible alternative—a fuse-based circuit breaker with current commutation process enhanced by an external transverse magnetic field(ETMF)—is proposed by the *** main advantage lies in the fast current commutation achieved by an ETMF-enhanced three-stage increase of the vacuum arc *** study of the current commutation process is mainly represented by the authors,and the influencing factors of the current commutation—contact opening speed and ETMF current—are *** last,the proposed circuit breaker is verified by an experiment,whose results show that a short-circuit current of 42 kA can be interrupted within just 2 ms.

关键词： vacuum transverse interrupt

Selective deposition of a MOF at the spikes of Au nanostars for SERS detection

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Nano Research 2024年第10期17卷 9166-9173页

作者： yi Liu Ka Kit Chui Xinyue Xia Han Zhang Xiaolu zhuo Jianfang Wang School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China Department of Physics The Chinese University of Hong KongShatinHong Kong 999077China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310000China

In the pursuit of advancing molecular sensing through surface-enhanced Raman spectroscopy(SERS),the combination of plasmonic nanoparticles and metal-organic frameworks(MOFs)has emerged as a highly effective approach to enhance the sensitivity and selectivity of SERS ***,most prior investigations have predominantly focused on MOF-coated plasmonic nanoparticles in core@shell or layer-by-layer configurations,leaving a notable knowledge gap in exploring alternative *** we present a facile method to construct a particle-on-mirror architecture by selectively coating a MOF,zeolitic imidazolate framework-8(ZIF-8),onto the tips of Au nanostars and subsequently depositing the resultant nanoparticles onto a Au *** design integrates the electric field enhancement at the sharp tips and nanogaps,along with the molecular enrichment function within the porous MOF immobilized at the tips and nanogaps,leading to a substantial boost in the SERS signal *** a unique SERS platform enables consistent and outstanding SERS performance for analytes of different *** work opens up a promising strategy for constructing multifunctional nanostructures for sensitive SERS detection in real-life scenarios.

关键词： electric field enhancement gold nanostars metal-organic frameworks molecular enrichment plasmon coupling surfaceenhanced Raman spectroscopy(SERS)substrates

The principle and amelioration of lithium plating in fast-charging lithium-ion batteries

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Journal of Energy Chemistry 2024年第10期97卷 453-459,I0009页

作者： yi Yang Xia-Lin Zhong Lei Xu zhuo-Lin Yang Chong Yan Jia-Qi Huang School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Yangtze River Delta Graduate School of Beijing Institute of Technology Jiaxing 314003ZhejiangChina

Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of ***,we investigate the Li plating behavior in porous electrodes under the restricted transport of Li^(+).Based on the theoretical model,it can be concluded that the Li plating on the anodeseparator interface(ASI)is thermodynamically feasible and kinetically ***,the prior deposition of metal Li on the ASI rather than the anode-current collector interface(ACI)is verified *** order to facilitate the transfer of Li^(+)among the electrode and improve the utilization of active materials without Li plating,a bilayer asymmetric anode composed of graphite and hard carbon(GH)is *** and simulation results suggest that the GH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li *** work provides new insights into the behavior of Li plating and the rational design of electrode structure.

关键词： Graphite Hard carbon Fast charging Lithium plating Lithium-ion batteries

Microstructure and Mechanical Properties of the Ti_(62)Nb_(12)Mo_(12)Ta_(12)W_(2)Refractory High Entropy Alloy Prepared through Spark Plasma Sintering

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1387-1398页

作者： Zirui Chen Liyuan Wang Jiayu Zhao Guanhua Cui zhuo Gao Zhiyuan Fan Xiaohui shi Junwei Qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

A refractory high entropy alloy Ti_(62)Nb_(12)Mo_(12)Ta_(12)W_(2)was prepared by mechanical alloying and spark plasma *** microstructure and mechanical properties of the Ti_(62)Nb_(12)Mo_(12)Ta_(12)W_(2)alloy were *** experimental results show that the microstructure of the alloy is composed of two BCC phases,an FCC precipitated phase,and the precipitated phase which is a mixture of TiC,TiN and *** alloy exhibits good room temperature compressive *** plasticity of the sample sintered at 1550℃can reach 10.8%,and for the sample sintered at 1600℃,the yield strength can be up to 2032 MPa,in the meantime the plasticity is 9.4%.The alloy also shows high strength at elevated *** yield strength of the alloy exceeds 420 MPa at 900℃,and value of which is still above 200 MPa when the test temperature reaches 1000℃.Finally,the compressive yield strength model at room temperature is *** prediction error of the model ranges from−7.9%to−12.4%,expressing fair performance.

关键词： Refractory high-entropy alloy(RHEA) Mechanical alloying Mechanical properties Model Spark plasma sintering