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Understanding the spatial interaction of ultrasounds based on three-dimensional dual-frequency ultrasonic field numerical simulation

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China Foundry 2024年第1期21卷 29-43页

作者： Zhao-yang Yin Qi-chi Le Yan-chao Jiang Da-zhi Zhao Qi-yu Liao Qi Zou Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

A transient 3D model was established to investigate the effect of spatial interaction of ultrasounds on the dual-frequency ultrasonic field in magnesium alloy *** effects of insertion depth and tip shape of the ultrasonic rods,input pressures and their ratio on the acoustic field distribution were discussed in ***,the spacing,angle,and insertion depth of two ultrasonic rods significantly affect the interaction between distinct *** a result,various acoustic pressure distributions and cavitation regions are *** spherical rods mitigate the longitudinal and transversal attenuation of acoustic pressure and expand the cavitation volume by 53.7%and 31.7%,respectively,compared to the plate and conical *** the input pressure will enlarge the cavitation region but has no effect on the acoustic pressure distribution *** acoustic pressure ratio significantly affects the pressure distribution and the cavitation region,and the best cavitation effect is obtained at the ratio of 2:1(P15:P20).

关键词： dual-frequency ultrasonic numerical model acoustic pressure spatial interaction magnesium alloy

Exceptional point enhanced nanoparticle detection in deformed Reuleaux‑triangle microcavity

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Frontiers of Optoelectronics 2024年第3期17卷 83-91页

作者： Jinhao Fei Xiaobei Zhang Qi Zhang Yong Yang Zijie Wang Chuanlu Deng Yi Huang Tingyun Wang Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced CommunicationShanghai Institute for Advanced Communication and Data ScienceSchool of Communication and Information EngineeringShanghai UniversityShanghai 200444China

In this paper,we propose a deformed Reuleaux-triangle resonator(RTR)to form exceptional point(EP)which results in the detection sensitivity enhancement of *** introducing single nanoparticle to the deformed RTR at EP,frequency splitting obtains an enhancement of more than 6 times compared with non-deformed *** addition,EP induced a result that the far feld pattern of chiral mode responses signifcantly to external perturbation,corresponding to the change in internal ***,single nanoparticle with far distance of more than 4000 nm can be detected by measuring the variation of far feld directional *** to traditional frequency splitting,the far feld pattern produced in deformed RTR provides a cost-efective and convenient path to detect single nanoparticle at a long distance,without using tunable laser and external *** structure indicates great potential in high sensitivity sensor and label-free detector.

关键词： Exceptional point Deformed microcavity Nanoparticle detection Far-feld pattern

Natural variation in maize gene ZmSBR1 confers seedling resistance to Fusarium verticillioides

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The Crop Journal 2024年第3期12卷 836-844页

作者： Yunxia Song Peipei Ma Jingyang Gao Chaopei Dong Zhao Wang Yifan Luan Jiafa Chen Doudou Sun Pei Jing Xuecai Zhang Weibin Song Zijian Zhou Jianyu Wu College of Agronomy Henan Agricultural UniversityZhengzhou 450002HenanChina College of Life Sciences Henan Agricultural UniversityZhengzhou 450002HenanChina Global Maize Program International Maize and Wheat Improvement Center(CIMMYT)Apdo 6-64106600 MexicoDFMexico National Maize Improvement Center Department of Plant Genetics and BreedingChina Agricultural UniversityBeijing 100193China

Maize seedling blight caused by Fusarium verticillioides is a widely occurring maize disease,but the genetics and mechanisms of resistance are not well *** this study,GWAS performed by MLM and 3VmrMLM identified 40 and 20 QTNs,associated with seedling blight *** methods identified 49 and 36 genes,*** verification of candidate gene ZmSBR1 identified by both methods showed that the resistance of a mutant line to seedling blight decreased by 0.37 grade points after inoculation with ***,compared with the *** length of the stem rot lesion caused by *** increased by 86%in mutant seedlings,and the relative length of the adult plant stalk rot increased by 35%in mutant plants compared to the wild type after inoculation with Fusarium *** analysis showed that expression of defense-related genes after inoculation was down-regulated in the mutant compared to the wild type,synthesis of secondary metabolites associated with resistance was reduced,and the immune response triggered by PAMP decreased,resulting in decreased resistance of mutant maize *** gene association analysis showed that most maize inbred lines carried the susceptible haplotype.A functional PCR marker was *** results demonstrated that ZmSBR1 conferred resistance to multiple Fusarium diseases at the seedling and adult growth stages and had important application value in breeding.

关键词： Seedling blight Stalk rot Multiple disease resistance

Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive

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Journal of Renewable Materials 2024年第2期12卷 235-244页

作者： Qianyu Zhang Shi Chen Long Cao Hong Lei Antonio Pizzi Xuedong Xi Guanben Du Yunnan Key Laboratory of Wood Adhesives and Glue Products College of Material Science and EngineeringSouthwest Forestry UniversityKunming650224China International Joint Research Center for Biomass Materials Southwest Forestry UniversityKunming650224China College of Chemical and Materials Engineering Zhejiang A&F UniversityHangzhou311300China LERMAB University of LorraineEpinal88000France

Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood ***,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of *** results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG ***,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding *** results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water *** shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application.

关键词： Urea-glyoxal resin hexamethylene diamine wood adhesives water resistance

Prevalence of vegetation browning in China’s drylands under climate change

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Geography and Sustainability 2024年第3期5卷 405-414页

作者： Li Fu Guolong Zhang Jianping Huang Ming Peng Lei Ding Dongliang Han Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China

Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even ***,detailed analyses about greening reversal or increased browning of vegetation remain *** this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to *** also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation *** find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s *** trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/*** research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate ***,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation *** browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.

关键词： China’s drylands Ecological restoration programs Climate change Greening to browning reversal BFAST

Wavelet Multi-Resolution Interpolation Galerkin Method for Linear Singularly Perturbed Boundary Value Problems

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 297-318页

作者： Jiaqun Wang Guanxu Pan Youhe Zhou Xiaojing Liu School of Management Science and Engineering Anhui University of Finance and EconomicsBengbu233030China Key Laboratory of Mechanics on Disaster and Environment in Western China The Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China

In this study,a wavelet multi-resolution interpolation Galerkin method(WMIGM)is proposed to solve linear singularly perturbed boundary value *** conventional wavelet schemes,the proposed algorithm can be readily extended to special node generation techniques,such as the Shishkin *** a wavelet method allows a high degree of local refinement of the nodal distribution to efficiently capture localized steep *** the shape functions possess the Kronecker delta property,making the imposition of boundary conditions as easy as that in the finite element *** numerical examples are studied to demonstrate the validity and accuracy of the proposedwavelet *** results showthat the use ofmodified Shishkin nodes can significantly reduce numerical oscillation near the boundary *** with many other methods,the proposed method possesses satisfactory accuracy and *** theoretical and numerical results demonstrate that the order of theε-uniform convergence of this wavelet method can reach 5.

关键词： Wavelet multi-resolution interpolation Galerkin singularly perturbed boundary value problems mesh-free method Shishkin node boundary layer

Metal-metal bonds in Zintl clusters:Synthesis,structure and bonding in[Fe_(2)Sn_(4)Bi_(8)]^(3-)and[Cr_(2)Sb_(12)]^(3-)

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Chinese Chemical Letters 2024年第8期35卷 558-566页

作者： Ya-Nan Yang Zi-Sheng Li Sourav Mondal Lei Qiao Cui-Cui Wang Wen-Juan Tian Zhong-Ming Sun John E.McGrady State Key Laboratory of Element-Organic Chemistry Tianjin Key Lab for Rare Earth Materials and ApplicationsSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China Department of Chemistry University of OxfordInorganic Chemistry LaboratoryOxfordOX13QRUnited Kingdom

We report here the synthesis and characterization of two new members of the M2 E 12 family of endohe-dral Zintl clusters,[Fe_(2)Sn_(4)Bi_(8)]^(3-)and[Cr_(2)Sb_(12)]^(3-),both of which contain open-shell metal dimers encap-sulated inside a triple-decker cluster of main-group *** 75-electron[Fe_(2)Sn_(4)Bi_(8)]^(3-)cluster has a D4h-symmetric structure,while[Cr_(2)Sb_(12)]^(3-),despite having the same 75-electron count,is strongly dis-torted to a geometry that resembles a CrSb_(8)crown capped by a CrSb_(4)*** structural differences between the two are driven by the increasing availability of 3d electron density in the earlier transi-tion metal,which leads,ultimately,to different electronic configurations in the two *** trends precisely mirror those observed in the ME_(10)and ME_(12)families containing a single transition metal ion.

关键词： Zintl anions Endohedral clusters Metal-metal bond Second-order Jahn-Teller effect DFT calculation

Rapid growth in a large Cambrian apex predator

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National Science Review 2024年第3期11卷 128-136页

作者：吴雨 Stephen Pates Daniel Pauly 张兴亮傅东静 State Key Laboratory of Continental Dynamics and Shaanxi Key Laboratory of Early Life and Environment Department of Geology Northwest University Department of Zoology University of Cambridge Institute for the Oceans and Fisheries University of British Columbia Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences

Despite the importance of ontogenetic data on early diverging euarthropods to our understanding of the ecology and evolution of past life, the data are distinctly lacking, as reconstructing life histories of fossil animals is often challenging. Here we report the growth trajectory of frontal appendages of the apex predator Amplectobelua symbrachiata, one of the most common radiodont arthropods from the early Cambrian Chengjiang biota(c. 520 Ma) of China. Analysis of 432 specimens(9.1–137.1 mm length; 1.3–25.6 mm height) reveals that appendages grew isometrically, with an estimated maximum size of the whole animal of c. 90 cm. Individuals grew rapidly compared to extant arthropods, as assessed using the electronic length-frequency analysis(ELEFAN) approach. Therefore, we show that the Cambrian apex predator A. symbrachiata was an extremely fast-growing arthropod, with an unusual life history strategy that formed as part of the escalatory ‘arms race’ that shaped the Cambrian explosion over 500 Ma.

关键词： stem-group Euarthropoda Radiodonta post-embryonic development growth dynamics Cambrian Explosion

Study on the low mechanical anisotropy of extruded Mg-Zn-Mn-Ce-Ca alloy tube in the compression process

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Journal of Magnesium and Alloys 2024年第3期12卷 1054-1067页

作者： Dandan Li Qichi Le Xiong Zhou Xiaoqiang Li Chenglu Hu Ruizhen Guo Tong Wang Ping Wang Wenxin Hu The Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030China

In this study,the extruded Mg-Zn-Mn-Ce-Ca alloy tube with a low compression anisotropy along the ED,45ED and TD was *** effect of the second phases,initial texture and deformation behavior on this low mechanical anisotropy was *** results revealed that the alloy tube contains the high content(Mg1-xZnx)11Ce phase and the low content of Mg12Ce *** second phases are respectively incoherent and coherent with the Mg matrix,and their influence can be ***,the alloy tube exhibited a weak basal fiber texture,where the c-axis was aligned along the 0°∼30°tilt from TD to *** a texture made the initial deformation(at 1.0%∼1.6%strain)of the three samples controlled by comparable basal*** deformation progressed(1.6∼9.0%strain),larger amounts of ETWs nucleated and gradually approached saturation in the three samples,re-orienting the c-axis to a 0°∼±30°deviation with respect to the loading ***,the prismatic and pyramidalslips replaced the dominant deformation progressively until ***,the similar deformation mechanisms determined by the weak initial texture in the three samples contribute to the comparable strain hardening rates,resulting in the low compressive anisotropy of the alloy tube.

关键词： Mg alloy tube Low mechanical anisotropy Weak texture Deformation mechanism.