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High strength Al-Cu-Mg based alloy with synchronous improved tensile properties and hot-cracking resistance suitable for laser powder b e d fusion

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Journal of Materials Science & Technology 2023年第10期141卷 155-170页

作者： Q.Z.Wang n.kang X.Lin M.EL Mansori W.D.Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Arts et Metiers Institute of Technology MSMPHESAM UniversitéChâlons-en-Champagne F-51006France Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’an 710072China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843USA

In present work,a novel crack-free Al-Cu-Mg-Si-Ti alloy with synchronous improved tensile properties and hot-cracking resistance was proposed and successfully manufactured by laser powder bed fusion(LPBF).The microstructure evolution behaviors and the corresponding strengthening mechanisms were investigated in *** LPBF-processed Al-Cu-Mg-Si-Ti alloy presents a heterogeneous microstructure consisting of ultrafine equiaxed grains(UFGs)at the boundary and coarse columnar grains(CGs)at the center of the single molten ***-precipitated D022-Al 3 Ti particles were found to act as the nuclei to refine the grains at the boundary of the molten pool during solidification process,which is attributed to the low cooling rate providing the sufficient incubation time for the precipitation of D022-Al 3 *** are two orientation relationships(ORs)betweenα-Al and D022-Al 3 Ti,i.e.[001]α-Al//[001]D022-Al3Ti,(200)α-Al//(200)D022-Al3Ti and[1¯1¯2]α-Al//[¯111]D022-Al3Ti,(1¯11)α-Al//(¯11¯2)D022-Al3Ti,which are two of the eight ORs predicted with the E2EM *** grains in present alloy,no matter for UFGs or CG,exhibited high critical hot-cracking stress,which means a strong hot-cracking ***-nanoprecipitation of Cu-,Mg-,and Si-rich Q’and S’phases was introduced to enhance the mechanical performance ofα-Al *** as-built sample exhibits superior tensile properties,with the yield strength(YS)of 473±8 MPa,ultimate tensile strength(UTS)of 541±2 MPa and elongation(EI)of 10.9%±1.2%.

关键词： Laser powder bed fusion High strength Al-Cu-Mg alloys Duplex microstructure Precipitation Tensile properties

Microstructure evolution and mechanical properties at high temperature of selective laser melted AlSi10Mg

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Journal of Materials Science & Technology 2021年第3期62卷 162-172页

作者： Y.Cao X.Lin Q.Z.Wang S.Q.Shi L.Ma n.kang W.D.Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’an 710072China

In this study,the microstructure and tensile properties of selective laser melted AlSilOMg at elevated temperature were investigated with focus on the interfacial ***-situ SEM and in-situ EBSD analysis were proposed to characterize the microstructural evolution with *** as-fabricated AlSilOMg sample presents high tensile strength with the ultimate tensile strength(UTS)of~450 MPa and yield strength(YS)of~300 MPa,which results from the mixed strengthening mechanism among grain boundary,solid solution,dislocation and Orowan looping *** holding at the temperature below 200℃for 30 min,the micro structure presents little change,and only a slight decrement of yield strength appears due to the relief of the residual ***,when the holding temperature further increases to 300℃and 400℃,the coarsening and precipitation of Si particles inα-Al matrix occur obviously,which leads to an obvious decrease of solid solution *** the same time,matrix softening and the weakness of dislocation strengthening also play important *** the holding temperature reaches to 400℃,the yield strength decreases significantly to about 25 MPa which is very similar to the as-cast Al *** might be concluded that the YS is dominated by the matrix *** the softening mechanism counteracts work hardening,the extremely high elongation occurs.

关键词： Selective laser melting AlSi10Mg Microstructure In-situ EBSD High temperature tensile property

Classical Electromagnetic Field Theory in the Presence of Magnetic Sources

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Chinese Physics Letters 2003年第3期20卷 321-324页

作者： Li kang Chen Wen-Jun Carlos M. naón Department of Physics Hangzhou Teacher's College Hangzhou 310036 Department of Physics Zhejiang University Hangzhou 310027 Instituto de Física La Plata Departamento de Física Facultad de Ciencias Exactas Universidad Nacional de La Plata CC 67 1900 La Plata Argentina

Using two new well-defined four-dimensional potential vectors, we formulate the classical Maxwell field theory in a form which has manifest Lorentz covariance and SO(2) duality symmetry in the presence of magnetic sources. We set up a consistent Lagrangian for the theory. Then from the action principle we obtain both Maxwell's equation and the equation of motion of a dyon moving in the electromagnetic field.

关键词： Maxwell equations

Analyses of plasma reactive sputter deposition of Cn_x films by OES

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Chinese Science Bulletin 1997年第21期42卷 1792-1795页

作者： Zhao, J kang, n Wang, JG Wang, RY Xu, JR Chinese Acad Sci Inst Phys Lab Opt Phys Beijing 100080 Peoples R China

OPTICAL emission spectroscopy (OES) is generally used in diagnosis on the various plasma filmdeposition processes to understand the mechanism of film growth. However, although the de-position precursors have been predicted such as Cn radicals and nitrogen atoms, up tonow no diagnostic work on Cn_x film deposition process, as we know, has been reported *** previously reported research work, the properties of Cn_x film display some obvious dif-ference. For instance, some Cn_x films have extreme mechanical properties with hardness

关键词： carbon nitride fiim optical emission spectras optical gap.

Transcriptomic and metabolomic analyses of cucumber fruit peels reveal a developmental increase in terpenoid glycosides associated with age-related resistance to Phytophthora capsici

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Horticulture Research 2017年第1期4卷 266-276页

作者： Ben n Mansfeld Marivi Colle Yunyan.kang A Daniel Jones Rebecca Grumet Department of Horticulture Graduate Program in Plant BreedingGenetics and BiotechnologyMichigan State UniversityEast Lansing48824MIUSA College of Horticulture South China Agricultural UniversityGuangzhou510642China Department of Biochemistry and Molecular Biology Michigan State UniversityEast Lansing48824MIUSA Department of Chemistry Michigan State UniversityEast Lansing48824MIUSA

The oomycete,Phytophthora capsici,infects cucumber(Cucumis sativus L.)*** age-related resistance(ARR)to this pathogen was previously observed in fruit of cultivar‘Vlaspik’and shown to be associated with the *** fruits are highly susceptible,but develop resistance at~10–12 days post pollination(dpp).Peels from resistant(16 dpp)versus susceptible(8 dpp)age fruit are enriched with genes associated with defense,and methanolic extracts from resistant age peels inhibit pathogen *** we compared developing fruits from‘Vlaspik’with those of‘Gy14’,a line that does not exhibit *** analysis of peels of the two lines at 8 and 16 dpp identified 80 genes that were developmentally upregulated in resistant‘Vlaspik’16 dpp versus 8 dpp,but not in susceptible‘Gy14’at 16 dpp.A large number of these genes are annotated to be associated with defense and/or specialized metabolism,including four putative resistance(R)genes,and numerous genes involved in flavonoid and terpenoid synthesis and *** metabolomic analysis was performed on extracts from 8 and 16 dpp‘Vlaspik’and‘Gy14’fruit peels using Ultra-Performance Liquid Chromatography and Quadrupole Time-of-Flight Mass *** analysis of the metabolomes identified 113 ions uniquely abundant in resistant‘Vlaspik’16 dpp peel *** most abundant compounds in this group had relative mass defects consistent with terpenoid *** of the three most abundant ions were annotated as glycosylated nor-terpenoid ***,these analyses reveal potential mechanisms by which ARR to *** may be conferred.

关键词： metabolism resistance abundant

Generation of new glutinous rice by CRISPR/Cas9-targeted mutagenesis of the Waxy gene in elite rice varieties

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Journal of Integrative Plant Biology 2018年第5期60卷 369-375页

作者： Jinshan Zhang Hui Zhang Jose Ramón Botella Jian.kang Zhu Shanghai Center for Plant Stress Biology and Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 201602China University of Chinese Academy of Sciences Shanghai 201602China Department of Horticulture and Landscape Architecture Purdue UniversityWest LafayetteIN 47907USA Plant Genetic Engineering Laboratory School of Agriculture and Food SciencesUniversity of QueenslandBrisbane QLD 4072Australia

In rice, amylose content （AC） is controlled by a single dominant Waxy gene. We used Clustered Regularly Interspaced Short Palindromic Repeats （CRISPR）/CRISPR-associated 9 （Casg） to introduce a loss-of-function mutation into the Waxy gene in two widely cultivated elite japonica varieties. Our results show that mutations in the Waxy gene reduce AC and convert the rice into glutinous ones without affecting other desirable agronomic traits, offering an effective and easy strategy to improve glutinosity in elite varieties. Importantly, we successfully removed the transgenes from the progeny. Our study provides an example of generating improved crops with potential for commercialization, by editing a gene of interest directly in elite crop varieties.

关键词： Generation of new glutinous rice by CRISPR/Cas9-targeted mutagenesis of the Waxy gene in elite rice varieties Figure AC

COnTACT ALGORITHMS FOR COnTACT DYnAMICAL SYSTEMS

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Journal of Computational Mathematics 1998年第1期16卷 1-14页

作者： kang Feng 中科院计算数学与科学工程计算所北京

In this paper, we develop a general way to construct contact algorithms for contact dynamical systems. Such an algorithm requires the corresponding step transition map preserve the contact structure of the underlying contact phase space. The constructions are based on the correspondence between the contact geometry of R2n+1 and the conic symplectic one of R2n+2 and therefore, the algorithms are derived naturally from the symplectic algorithms of Hamiltonian systems.

关键词： contact algorithms contact systems conic symplectic geometry generating functions

Primality Testing for numbers of the Form h·2~n± 1

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Journal of Systems Science & Complexity 2019年第5期32卷 1473-1478页

作者： HUAnG Dandan.kang Yunling School of Software Engineering and School of Cybersecurity Jinling Institute of TechnologyNanjing 211169China School of Statistics and Mathematics Nanjing Audit UniversityNanjing 211815China.

This paper studies the problem of primality testing for numbers of the form h · 2~n± 1,where h < 2~n is odd, and n is a positive integer. The authors describe a Lucasian primality test for these numbers in certain c... 详细信息

This paper studies the problem of primality testing for numbers of the form h · 2~n± 1,where h n is odd, and n is a positive integer. The authors describe a Lucasian primality test for these numbers in certain cases, which runs in deterministic quasi-quadratic time. In particular, the authors construct a Lucasian primality test for numbers of the form 3 · 5 · 17 · 2~n± 1, where n is a positive integer, in half of the cases among the congruences of n modulo 12, by means of a Lucasian sequence with a suitable seed not depending on n. The methods of Bosma(1993), Berrizbeitia and Berry(2004), Deng and Huang(2016) can not test the primality of these numbers.

关键词： Lucasian primality test Lucasian sequence primality testing reciprocity law

Regularity of Weak Solutions of nonlinear Equations with Discontinuous Coefficients

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Acta Mathematica Sinica,English Series 2005年第4期21卷 705-714页

作者： Qi kang RAn Departtnent of Applied Mathematics Shanghai University of Finance and Economics Shanghai 200433 P. R. China

In this paper, we prove that the weak solutions u∈Wloc^1, p （Ω）（1 〈p〈∞） of the following equation with vanishing mean oscillation coefficients A（x）： -div[（A（x）△↓u·△↓u）p-2/2 A（x）△↓u＋│F（x）│^p-2 F（x）]=B（x, u, △↓u）, belong to Wloc^1, q （Ω）（A↓q∈（p, ∞）, provided F ∈ Lloc^q（Ω） and B（x, u, h） satisfies proper growth conditions where Ω ∪→R^n（n≥2） is a bounded open set, A（x）=（A^ij（x）） n×n is a symmetric matrix function.

关键词： nonlinear elliptic equations Local Regularity Calderon-Zygmund decomposition VMO space Local weak L^p(Ω) space