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What diameter?What height?Influence of measures of average tree size on area-based allometric volume relationships

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Forest Ecosystems 2024年第1期11卷 100-109页

作者： Yilin Wang john A.Kershaw Mark j.Ducey yuan Sun james B.McCarter Integrated Forest Mensuration and Systems Analysis Laboratory Faculty of Forestry and Environmental ManagementUniversity of New BrunswickFrederictonNBCanada Department of Natural Resources and the Environment University of New HampshireDurhamNHUSA College of Forestry Nanjing Forestry UniversityNanjing210037China Scientific Programmer RayonierYuleeFLUSA

Volume is an important attribute used in many forest management *** from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume *** density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height *** density was not included(Volume=f(Diameter,Height)),the opposite was *** models with density included,moment-based estimators of stand diameter and height performed better than all other *** models without density,largest tree estimators of stand diameter and height performed better than other *** overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.

关键词： Allometric relationships Stand structure Volume estimation Stand-level attributes

Four Late-type Galaxies with Double Radio Lobes and Properties of Such Galaxies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： Z.S.yuan X.Y.Gao Z.L.Wen j.L.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utilizing the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VLA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four Late-type Galaxies with double Radio Lobes(La GRLs):j0217-3645,j0947+6220,j1412+3723 and j1736+*** previously known La GRLs,we confirm the correlation between radio power P_(1.4GHz)and stellar mass M_(*)of host ***(25/35)La GRLs belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz)-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the majority(31/36)of La GRLs are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:jets galaxies:spiral radio continuum:galaxies

InGaN multiple quantum well based light-emitting diodes with indium composition gradient InGaN quantum barriers

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Optoelectronics Letters 2024年第2期20卷 89-93页

作者： SANG Xien XU yuan YIN Mengshuang WANG Fang LIOU juin j LIU Yuhuai National Center for International joint Research of Electronic Materials and Systems International Joint-Laboratory of Electronic Materials and Systems of Henan ProvinceSchool of Electrical and Information EngineeringZhengzhou UniversityZhengzhou 450001China Institute of Intelligence Sensing Zhengzhou UniversityZhengzhou 450001China Research Institute of Industrial Technology Co. Ltd.Zhengzhou UniversityZhengzhou 450001China Zhengzhou Way Do Electronics Co. Ltd.Zhengzhou 450001China School of Electrical and Information Engineering North Minzu UniversityYinchuan 750001China1

To improve the internal quantum efficiency(IQE)and light output power of In Ga N light-emitting diodes(LEDs),we proposed an In-composition gradient increase and decrease In Ga N quantum barrier *** analysis of its P-I graph,carrier concentration,and energy band diagram,the results showed that when the current was 100 m A,the In-composition gradient decrease quantum barrier(QB)structure could effectively suppress electron leakage while improving hole injection efficiency,resulting in an increase in carrier concentration in the active region and an improvement in the effective recombination rate in the quantum well(QW).As a result,the IQE and output power of the LED were effectively improved.

关键词： diodes quantum gradient

Recent advancements in thermal conductivity of magnesium alloys

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journal of Magnesium and Alloys 2024年第5期12卷 1687-1708页

作者： Hao Lv jun Tan Qian yuan Fanglei Wang Yunxuan Zhou Quan Dong Aitao Tang jürgen Eckert Bin jiang Fusheng Pan National Engineering Research Center for Magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 12Leoben A-8700Austria Erich Schmid Institute of Materials Science Austrian Academy of SciencesJahnstraße 12Leoben A-8700Austria

As highly integrated circuits continue to advance,accompanied by a growing demand for energy efficiency and weight reduction,materials are confronted with mounting challenges pertaining to thermal conductivity and lightweight *** virtue of numerous intrinsic mechanisms,as a result,the thermal conductivity and mechanical properties of the Mg alloys are often inversely related,which becomes a bottleneck limiting the application of Mg *** on several effective modification methods to improve the thermal conductivity of Mg alloys,this paper describes the law of how they affect the mechanical properties,and clearly indicates that peak aging treatment is one of the best ways to simultaneously enhance an alloy's thermal conductivity and mechanical *** the most frequently used Mg alloy,cast alloys exhibit substantial potential for achieving high thermal ***,recent reports indicate that hot deformation can significantly improve the mechanical properties while maintaining,and potentially slightly enhancing,the alloy's thermal *** presents a meaningful way to develop Mg alloys for applications in the field of small-volume heat dissipation components that require high *** comprehensive review begins by outlining standard testing and prediction methods,followed by the theoretical models used to predict thermal conductivity,and then explores the primary influencing factors affecting thermal *** review summarizes the current development status of Mg alloys,focusing on the quest for alloys that offer both high thermal conductivity and high *** concludes by providing insights into forthcoming prospects and challenges within this field.

关键词： Mg alloy Thermal conductivity Mechanical properties Solute atom Second phase

Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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journal of Rare Earths 2024年第7期42卷 1289-1297,I0004页

作者： Yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui Zheng Hongxia Meng Zhigang Zheng Deyang Chen Shengfu yuan Weixing Xia Dechang Zeng j.P.Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan528437China Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang529500China Laboratory of Rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China Department of Physics University of Texas at ArlingtonArlingtonTX76019USA

SmCo based films with excellent intrinsic magnetic properties have promising applications in micro-electro-mechanical system(MEMS).However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity(Hc)and remanence(Mr)of films are difficult to enhance *** this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering *** effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are *** adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5 is obtained,leading to the increase of coercivity of the films from 30 to 34 *** influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was *** the deposition temperature increases from room temperature to 250℃,the coercivity will further increase from 34 to 51 ***,a severe kink is observed in the demagnetization curves due to the poor exchanged *** analysis of transmission electron microscopy(TEM)confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ***,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the *** the coercivity and the remanence ratio of the demagnetization curves are greatly *** propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： Rare earths SmCo based films Phase composition Crystallization conditions Coercivity Remanence ratio

Motor cortical circuit adaptations in parkinsonism

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Neural Regeneration Research 2024年第10期19卷 2107-2108页

作者： Hong-yuan Chu Department of Neurodegenerative Science Van Andel Research InstituteGrand RapidsMIUSA Aligning Science Across Parkinson’s(ASAP)Collaborative Research Network

Parkinson's disease is a chronic and progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta,which leads to the featured motor impairment of parki... 详细信息

关键词： parkin impairment rigidity

A vectorial model for the nonlinear gradient force exerted on metallic Rayleigh nanoparticles

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Chinese Optics Letters 2024年第2期22卷 207-213页

作者：朱政张聿全闵长俊 Aurèle j.LAdam H.Paul Urbach 袁小聪 Research Center for Humanoid Sensing Research Institute of Intelligent SensingZhejiang LabHangzhou 311100China Nanophotonics Research Center Institute of Microscale Optoelectronics&State Key Laboratory of Radio Frequency Heterogeneous IntegrationShenzhen UniversityShenzhen 518060China Optics Research Group ImPhys DepartmentFaculty of Applied SciencesDelft University of TechnologyDelft 2628 CJThe Netherlands

Optical tweezers have proved to be a powerful tool with a wide range of *** gradient force plays a vital role in the stable optical trapping of *** scalar method is convenient and effective for analyzing the gradient force in traditional optical ***,when the third-order nonlinear effect of the nano-object is stimulated,the scalar method cannot adequately present the optical response of the metal nanoparticle to the external optical ***,we propose a theoretical model to interpret the nonlinear gradient force using the vector *** combining the optical Kerr effect,the polarizability vector of the metallic nanoparticle is derived.A quantitative analysis is obtained for the gradient force as well as for the optical potential *** vector method yields better agreement with reported experimental *** suggest that this method could lead to a deeper understanding of the physics relevant to nonlinear optical trapping and binding phenomena.

关键词： gradient forces nonlinear effect metallic nanoparticles

A Stable Copper-based Metal-Azolate Framework for Efficient Electroreduction of CO_(2)to C_(2+)Products

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Chemical Research in Chinese Universities 2024年第4期40卷 664-669页

作者： LIU yuan-yuan ZHU Hao-Lin LIAO Pei-Qin CHEN Xiao-Ming Key Laboratory of Bioinorganic and Synthetic Chemistry Ministry of EducationGBRCE for Functional Molecular EngineeringSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou510275P.R.China Chemistry and Chemical Engineering Guangdong Laboratory Shantou515031P.R.China

Driven by renewable or excess electrical energy,electrochemical CO_(2)reduction reaction(eCO_(2)RR)represents a promising carbon-neutral approach to generating valuable low-carbon fuels by consuming CO_(2)and H_(2)O.C_(2+)products are one of the most economically valuable products among the reduction species of eCO_(2)RR,but there are still some challenges,such as low selectivity or low current *** this work,we showed that a copper-based metal-azolate framework(MAF),denoted as MAF-203,exhibits the high performance of eCO_(2)RR to yield C_(2+)products with the Faradaic efficiency(C_(2+))of 52.5%and a current density of 660 mA/cm^(2)at-1.2 V *** in a flow cell device under alkaline *** experiment,in situ infrared spectroscopy and the density functional theory(DFT)calculations showed that the electron donating effect of methyl substituents on organic ligands of the copper-based MAF could enhance the ligand field and activation of key intermediates(*CO and*CHO species),thus promoting the coupling of*CO and*CHO for yielding C_(2+)products.

关键词： Metal-organic framework Carbon dioxide Electroreduction C_(2+)product Metal-azolate framework

Interface structure of α-Mg/14H-LPSO:First-principles prediction and experimental study

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journal of Rare Earths 2024年第9期42卷 1792-1799,I0006页

作者： yuan Shi Xiaohua Zhang Hongyan Yue Chao Li School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin150040China

The interfacial structure of the α-Mg/14H-LPSO phase in rare earth-including magnesium alloy was investigated via high-angle annular dark-field scanning transmission electron microscopy(HAADFSTEM) imaging and first-principles calculations of density-functional *** possible interfacial models were constructed according to the different terminations of the LPSO phase,and the corresponding interfacial energies were calculated,from which the four most stable structures(Terl-MgY-hollow,Ter2-Zn-hollow,Ter3-MgYII-hollow and Ter4-Mg-bridge) were *** interfacial phase diagrams related to the Y chemical potentials were obtained from the calculations,and the most stable interfacial structure was ***-MgY-hollow and Ter2-Zn-hollow have the lowest interfacial energies in the range of-0.7 eV j/m^(2) for the interface model of α-Mg and 14H-LPSO phase structure with Ter2-Zn-hollow termination.

关键词： Rare earths Magnesium alloy HAADF-STEM LPSO First-principles Interface