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Taxonomic confusion of two tramp ant species： Iridomyrmex anceps and Ochetellus glaber are really species complexes

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Current Zoology 2011年第5期57卷 662-667页

作者： Benjamin d. HOFFMAnn Alan n. AndERSEn Xiang ZHAnG CSIRO Ecosystem Sciences Tropical Ecosystems Research Centre PMB 44 Winnellie NT 0822 Australia College of Plant Protection Fujian Agriculture and Forestry University Fuzhou Fujian 350002 China

Many invasive invertebrates belong to unresolved species complexes, and have a history of misidentification and in-appropriate management. Here we detail confusion surrounding the taxonomy and identification of two dolichoderine ant species, Iridomyrmex anceps Roger and OcheteUus glaber Mayr, which are commonly cited in the literature as having been spread widely by human commerce. We provide morphometric data and images strongly suggesting that these two ＂species＂ are instead com- plexes of species that are likely native to many regions where they are purportedly introduced. We take particular interest in the status of species referred to as L anceps and O. glaber in China, as this is the most northerly distribution of both genera. We con-clude by suggesting that many identifications of both species are likely to be unreliable, and we recommend against any manage- ment action aimed at controlling these species under the assumption that they are exotic [Current Zoology 57 （5）： 662-667, 2011].

关键词： Ant Exotic Invasive Invertebrate Management Tramp ant

Influence of Electromagnetic Stirring on the Macrosegregation in Arc Remelted Ti and Zr Alloy Ingots

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Journal of Iron and Steel Research International 2012年第S1期19卷 199-202页

作者： Alain Jardy Mathieu Revil-Baudard hervé Combeau Universite de Lorraine Institut Jean Lamour-Dépt.SI2MUMR CNRS 7198Ecole des MinesParc de SauruptNancy F-54042France

A numerical model of the VAR process has been developed in close collaboration with titanium and zirconium *** model is based on the solution of the coupled heat,mass and momentum transport equations in the whole ingot(liquid pool,mushy zone and solidified part)using a finite volume *** accounts for electromagnetic stirring, buoyancy flows and turbulence *** mechanisms implemented in the model include a full coupling between energy and solute transport in the mushy *** numerical model has been applied to simulate the remelting of *** influence of the applied magnetic field on the fluid flow and segregation behaviour,for a number of different stirring practices,is presented and ***,the macrosegregation in Zy4 ingots is *** comparison between the predicted segregation and the experimental results shows the importance of accounting for both the stirring and thermosolutal convection to forecast properly the segregation in remelted ingots.

关键词： Vacuum Arc Remelting simulation zirconium titanium macrosegregation stirring

Effect of nb on Microstructure Evolution in Cold Rolled dual-Phase Steels:Interaction of Recovery,Recrystallization and Phase Transformations

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Journal of Iron and Steel Research International 2011年第S1期18卷 228-232页

作者： Pottore n Fonstein n Bhatta Charya d Jansto S ArcelorMittal Global R and d 3001 E Columbus DrEast ChicagoIN 46312USA CBMM-Reference Metals Company 1000 Old Pond RoadBridgevillePA 15017USA

The effects of nb addition,individually and in combination with Ti,were evaluated over a range of coiling *** temperature influences the ratio of soluble and precipitated nb in the hot rolled steel containing 0.08 % C and 2.2 % *** bearing precipitates can co-precipitate on Tin and impact the microstructure and mechanical properties of the steel after annealing *** characterization revealed that recovery and recrystallization processes preceded austenite *** effects of nb on austenite formation in cold rolled steels during heating and isothermal holding and on austenite decomposition during subsequent cooling were investigated using *** addition of nb retarded ferrite recrystallization starting temperature,but had no significant effect on the starting temperature of austenite formation during *** nb addition also accelerated austenite formation once the transformation started,and was beneficial for the formation of a finer and homogeneous microstructure.

关键词： niobium dual-phase steel recovery recrystallization phase transformation

determination of the physical and interaction properties of sorghum grains:Application to computational fluid dynamics-discrete element method simulations of the fluid dynamics of a conical spouted bed

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Particuology 2021年第1期19卷 91-101页

作者： J.n.M.Batista d.A.Santos R.Bettega Federal University of São Carlos Department of Chemical EngineeringSPBrazil Institute of Chemistry Federal University of GoiásGOBrazil

Computational simulation is an important tool for design and improvement of industrial *** fluid dynamics(CFd)coupled with the discrete element method(dEM)has been applied to simulate drying equipment that usually involves gas-solid *** reliable results of CFd-dEM simulations,the properties related to the interactions of the material within the industrial equipment,such as the restitution or friction coefficients,must be *** this study,CFd-dEM was applied to simulate the fluid dynamics inside a conical spouted bed operating with sorghum *** physical properties of the particulate phase and the particle-particle and particle-wall interaction parameters were determined by the direct measurement approach and applied to *** interaction parameters were experimentally determined,including the particle-particle interaction parameters ofη=0.46,μ^(S)=0.79,andμ_(R)=0.70,and the particle-wall interaction parameters ofη=0.56,μ_(S)=0.75,andμ_(R)=*** simulated minimum spouting velocity and characteristic curves were compared with the experimental *** was good agreement between the simulated and experimental results.

关键词： Restitution coefficient Static friction coefficient Rolling friction coefficient CFd dEM

Evolution of X-pinch loads for pulsed power generators with current from 50 to 5000 kA

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Matter and Radiation at Extremes 2018年第6期3卷 267-277页

作者： T.A.Shelkovenko S.A.Pikuz I.n.Tilikin M.d.Mitchell S.n.Bland d.A.Hammer Cornell University IthacaNY14850USA P.n.Lebedev Institute Moscow119991Russia Blackett Laboratory Imperial College LondonLondonSW72AZUK University of Evansville EvansvilleINUSA

A review of X-pinches of various configurations and of different materials as an X-ray source for various applications is presented. Theadvantages and disadvantages of different designs of X-pinches as a load for generators with a wide range of output parameters and as a sourceof X-ray radiation for X-ray point-projection imaging were analyzed.

关键词： X-pinch X-ray source X-ray point-projection imaging

Anomalous acceleration of ions in a plasma accelerator with an anodic layer

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Plasma Science and Technology 2018年第3期20卷 95-105页

作者： V M BARdAKOV S d IVAnOV A V KAZAnTSEV n A STROKIn A n STUPIn Binhao JIAnG Zhenyu WAnG Irkutsk State Transport University Chernyshevsky Str.15664074IrkutskRussia national Research Irkutsk Technical University Lermontova Str.83664074IrkutskRussia department of Electrical Engineering Harbin Institute of TechnologyHarbin 150001People's Republic of China

In a plasma accelerator with an anodic layer(PAAL),we discovered experimentally the effect of‘super-acceleration'of the bulk of the ions to energies W exceeding the energy equivalent to the discharge voltage V_(d).The E×B discharge was ignited in an environment of atomic argon and helium and molecular *** charged argon ions were accelerated most effectively in the case of the largest discharge currents and pressure P of the working *** ions with W〉eV_(d)(e being the electron charge)were only recorded at maximum *** nitrogen was not accelerated to energies W〉e V_(d).Anomalous acceleration is realized in the range of radial magnetic fields on the anode 2.8×10^(–2)≤B_(rA)≤4×10^(–2)*** was also found analytically that the cathode of the accelerator can receive anomalously accelerated *** this case,the value of the potential in the anodic layer becomes higher than the anode potential,and the anode current exceeds some critical *** modeling in terms of the developed theory showed qualitative agreement between modeling data and measurements.

关键词： plasma sources particle orbit and trajectory particle measurements

Experimental study on microstructural and corrosion behaviors of friction stir processed steel with CoCrFeCuTi HEA reinforcement and effect of annealing

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Science China Technological Sciences 2025年第1期 233-250页

作者： S.Aravind KRISHnA n.RAdHIKA Alokesh PRAMAnIK n.JEYAPRAKASH department of Mechanical Engineering Amrita School of EngineeringAmrita Vishwa Vidyapeetham School of Civil and Mechanical Engineering Curtin University School of Mechanical and Electrical Engineering China University of Mining and Technology

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial applications. This can be resolved by employing surface modification techniques to modify the surface with the required characteristics. The present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA) as reinforcement and the property enhancements post-annealing. The synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17 μm mean particle size and body centred cubic(BCC) phase. The microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA filler. The microstructures of the samples annealed at 400℃, 550℃, 700℃ and 850℃ for 2 h also showed significant grain growth and grain refinements. The processed sample with HEA reinforcement annealed at 700℃ exhibited enhanced microhardness and tensile strength by 63% and 0.88 times than that of the processed sample with HEA pre-annealing. The subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed sample. Hot corrosion tests at 900℃ showcased excellent resistance for the HEA processed and annealed samples by 14.92%, 12.75%, and 14.83% against the samples pre-annealed under three different salt mixtures, and the corroded surface was analyzed.

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Creation and annihilation phenomena of electron and positron pairs in an oscillating field

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Chinese Physics B 2021年第7期30卷 151-156页

作者： M Jiang d d Su n S Lin Y J Li School of Science China University of Mining and TechnologyBeijing 100083China State Key Laboratory for Geomechanics and deep Underground Engineering China University of Mining and TechnologyBeijing 100083China Beijing national Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

The combination of an oscillating and a static field is used to study the creation and annihilation phenomena during the pair creation *** time evolution,spatial density and momentum distribution of the created particles for a fermionic system are presented,which demonstrate that with the increasing static field intensity,the number of the created particles experiences a distinguishable decrease in every period of the oscillating field,which is caused by the annihilation phenomena between the created electrons and positrons.

关键词： pair creation computational quantum field theory strong laser field

Studies on unfolding energy spectra of neutrons using maximumlikelihood expectation–maximization method

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nuclear Science and Techniques 2019年第9期30卷 24-33页

作者： Mehrdad Shahmohammadi Beni d.Krstic d.nikezic K.n.Yu department of Physics City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong China Faculty of Science University of Kragujevac Kragujevac Serbia State Key Laboratory of Marine Pollution City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong China

Energy spectra of neutrons are important for identification of unknown neutron sources and for determination of the equivalent dose. Although standard energy spectra of neutrons are available in some situations, e.g., for some radiotherapy treatment machines, they are unknown in other cases, e.g., for photoneutrons created in radiotherapy rooms and neutrons generated in nuclear reactors. In situations where neutron energy spectra need to be determined, unfolding the required neutron energy spectra using the Bonner sphere spectrometer (BSS) and nested neutron spectrometer (nnS) has been found promising. However, without any prior knowledge on the spectra, the unfolding process has remained a tedious task. In this work, a standalone numerical tool named ‘‘nRUunfold’’ was developed which could satisfactorily unfold neutron spectra for BSS or nnS, or any other systems using similar detection methodology. A generic and versatile algorithm based on maximum-likelihood expectation– maximization method was developed and benchmarked against the widely used STAY’SL algorithm which was based on the least squares method. The present method could output decent results in the absence of precisely calculated initial guess, although it was also remarked that employment of exceptionally bizarre initial spectra could lead to some unreasonable output spectra. The neutron count rates computed using the manufacturer’s response functions were used for sensitivity studies. The present nRUunfold code could be useful for neutron energy spectrum unfolding for BSS or nnS applications in the absence of a precisely calculated initial guess.

关键词： neutron spectrometry Maximum-likelihood expectation–maximization nested neutron spectrometer