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Partitioning Complete Graphs by Heterochromatic Trees

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Acta Mathematicae Applicatae Sinica 2012年第4期28卷 625-630页

作者： Ze-min JIN xue-liang LI Department of Mathematics Zhejiang Normal University Center for Combinatorics and LPMC Nankai University

A heterochromatie tree is an edge-colored tree in which any two edges have different colors. The heterochromatic tree partition number of an r-edge-colored graph G, denoted by tr （G）, is the minimum positive integer p such that whenever the edges of the graph G are colored with r colors, the vertices of G can be covered by at most p vertex-disjoint heterochromatic trees. In this paper we determine the heterochromatic tree partition number of r-edge-colored complete graphs. We also find at most tr（Kn） vertex-disjoint heterochromatic trees to cover all the vertices in polynomial time for a given r-edge-coloring of Kn.

关键词： edge-colored graph heterochromatic tree partition

High-throughput screening for biomedical applications in a Ti-Zr-Nb alloy system through masking co-sputtering

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Science China(Physics,Mechanics & Astronomy) 2019年第9期62卷 86-94页

作者： xue-hui Yan Jiang Ma Yong Zhang Beijing Advanced Innovation Center of Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China College of Mechatronic and Control Engineering Shenzhen UniversityShenzhen 518060China

A method of co-sputtering deposition combined with physical masking was applied to the parallel preparation of a ternary Ti-NbZr system alloy. Sixteen independent specimens with varying compositions were obtained. Their microstructure, phase structure,Young’s modulus, nanoindentation hardness, and electrochemical behavior in a phosphate buffer solution(PBS) were studied in detail. It was revealed that the Ti-Zr-Nb alloys possess a single BCC structure. As confirmed via nanoindentation tests, the Young’s modulus of the specimens ranged from 80.3 to 94.8 GPa and the nanoindentation hardness ranged from 3.6 to 5.0 *** optimizing the composition of the specimens, the Ti34Zr52Nb14 alloy was made to possess the lowest modulus in this work(76.5 GPa). Moreover, the Ti34Zr52Nb14 alloy showed excellent corrosion resistance in PBS without any tendency for pitting at anodic potentials up to 1 Vsce. These preliminary advantages offer the opportunity to explore new orthopedic implant alloys based on Ti-Zr-Nb alloys. Moreover, this work provides an effective method for the parallel preparation of biomedical alloys.

关键词： high-throughput biomedical materials co-sputtering physical mask Young’s modulus

Phosphate enrichment mechanism in CaO–SiO_2–FeO–Fe_2O_3–P_2O_5 steelmaking slags with lower binary basicity

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International Journal of minerals,Metallurgy and Materials 2016年第5期23卷 520-533页

作者： Jin-yan Li Mei Zhang min Guo xue-min Yang State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

The addition of silica to steelmaking slags to decrease the binary basicity can promote phosphate enrichment in quenched slag samples. In this study, we experimentally investigated phosphate enrichment behavior in CaO-SiO2-FeO-Fe203-P205 slags with a P205 content of 5.00% and the binary basicity B ranging from 1.0 to 2.0, where the （%Fe/O）/（%CaO） mass percentage ratio was maintained at 0.955. The experimental results are explained by the defined enrichment degree c, of solid solution 2CaO·SiO2-3CaO·P205 （C2S-C3P）, where R_C2S-C3P is a component of the developed ion and molecule coexistence theory （IMCT）-Ni model for calculating the mass action concentrations Ni of structural units in the slags on the basis of the IMCT. The asymmetrically inverse V-shaped relation be- tween phosphate enrichment and binary basicity B was observed to be correlated in the slags under applied two-stage cooling conditions. The maximum content of PROs in the C2S-C3P solid solution reached approximately 30.0% when the binary basicity B was controlled at 1.3.

关键词： phosphates enrichment mechanisms steelmaking slags basicity

Phylogeny of Trigonotis in China-with a special reference to its nutlet morphology and plastid genome

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Plant Diversity 2023年第4期45卷 409-421页

作者： xue-min Xu Dan-hui Liu Shi-Xin Zhu Zhen-Long Wang Zhen Wei Quan-Ru Liu School of Life Sciences Zhengzhou UniversityZhengzhou450001China College of Life Sciences Beijing Normal UniversityBeijing100875China

The genus Trigonotis comprises nearly 60 species mainly distributed in East and Southeast *** has the largest number of Trigonotis species in the world,with a total of 44 species,of which 38 are *** morphology is useful for the taxonomic delimitation of ***,there are still controversial circumscriptions of nutlet shape in some *** previous studies,interspecies phylogenetic relationships were inferred using few DNA markers and very few taxa,which possibly led to erroneous or incomplete *** this study,the nutlet morphology of 39 Trigonotis taxa and the characteristics of 34 complete chloroplast genomes(29 taxa)were investigated and ***,the phylogenetic relationships were discussed within this genus based on complete chloroplast *** the best of our knowledge,this study is the first comprehensive analysis of nutlet morphology and complete chloroplast genome of *** on nutlet morphology,Trigonotis can be divided into two groups:Group 1,hemispherical or oblique tetrahedron with carpopodiums,and Group 2,inverted tetrahedron without *** chloroplast genome of Trigonotis exhibited a typical quadripartite structure,including 84-86 protein-coding,37 transfer RNA,and 8 ribosomal RNA genes,with a total length of 147,247-148,986 *** in the junctions were well conserved in Trigonotis,similar to those in other Boraginaceae ***,Trigonotis chloroplast genomes showed relatively high diversity,with more conserved genic regions than intergenic regions;in addition,we detected 14 hot spots(Pi>0.005)in non-coding *** analyses based on chloroplast genome data identified highly resolved relationships between Trigonotis ***,Trigonotis was divided into two clades with strong support:one clade included species with hemispherical or oblique tetrahedron nutlets with carpopodiums and bracts,whereas the other clade included species with inverted te

关键词： Trigonotis Nutlet morphology Plastid genome Genome structure Phylogenetic analysis

Self-corrected unsupervised domain adaptation

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Frontiers of Computer Science 2022年第5期16卷 35-43页

作者： Yunyun WANG Chao WANG hui xue Songcan CHEN School of Computer Science and Engineering Nanjing University of Posts&TelecommunicationsNanjing 210046China School of Computer Science and Engineering Southeast UniversityNanjing 210096China School of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210023China

Unsupervised domain adaptation(UDA),which aims to use knowledge from a label-rich source domain to help learn unlabeled target domain,has recently attracted much *** methods mainly concentrate on source classification and distribution alignment between domains to expect the correct target *** in this paper,we attempt to learn the target prediction end to end directly,and develop a Self-corrected unsupervised domain adaptation(SCUDA)method with probabilistic label *** adopts a probabilistic label corrector to learn and correct the target labels ***,besides model parameters,those target pseudo-labels are also updated in learning and corrected by the anchor-variable,which preserves the class candidates for *** on real datasets show the competitiveness of SCUDA.

关键词： unsupervised domain adaptation adversarial Learning deep neural network pseudo-labels label corrector

Mesospheric tide comparisons at low latitudes observed by two collocated meteor radars

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Earth and Planetary Physics 2025年第1期9卷 54-68页

作者： Jian Li Wen Yi Xianghui xue Jie Zeng HaiLun Ye JianYuan Wang JinSong Chen Na Li TingDi Chen Chinese Academy of Sciences(CAS)Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology Anhui Mengcheng Geophysics National Observation and Research StationUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical Science and Technology Harbin 150001China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave PropagationQingdao 266107China Yunnan Kunming Electromagnetic Environment National Observation and Research Station Qujing Kunming 655000China

Accurate knowledge of mesospheric winds and waves is essential for studying the dynamics and climate in the mesosphere and lower thermosphere(MLT)*** this study,we conduct a comparative analysis of the mesosphere tidal results obtained from two adjacent meteor radars at low latitudes in Kunming,China,from November 2013 to December *** two radars operate at different frequencies of 37.5 MHz and 53.1 MHz,***,overall good agreement is observed between the two radars in terms of horizontal winds and tide *** results show that the dominant tidal waves of the zonal and meridional winds are diurnal and semidiurnal ***,we conduct an exhaustive statistical analysis to compare the tidal amplitudes and vertical wavelengths recorded by the dual radar systems,which reveals a high degree of alignment in tidal *** investigation includes variances and covariances of tidal amplitudes,which demonstrate remarkable consistency across measurements from both *** finding highlights clear uniformity in the mesospheric tidal patterns observed at low latitudes by the two neighboring meteor *** of the comparative analysis specifically underscore the significant correlation in vertical wavelength measurements,validating the robustness of radar observations for tidal research.

关键词： mesosphere and lower thermosphere region meteor radar mesospheric winds tides

Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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Earth and Planetary Physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao Tian Xianghui xue Christopher JScott HaiLun Ye JianFei Wu Wen Yi TingDi Chen XianKang Dou Institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).This study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

Pointwise manifold regularization for semi-supervised learning

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Frontiers of Computer Science 2021年第1期15卷 91-98页

作者： Yunyun WANG Jiao HAN Yating SHEN hui xue Department of Computer Science and Engineering Nanjing University of Posts&TelecommunicationsNanjing 210046China School of Computer Science and Engineering Southeast UniversityNanjing 210096China

Manifold regularization(MR)provides a powerful framework for semi-supervised classification using both the labeled and unlabeled *** constrains that similar instances over the manifold graph should share similar classification out-puts according to the manifold *** is easily noted that MR is built on the pairwise smoothness over the manifold graph,i.e.,the smoothness constraint is implemented over all instance pairs and actually considers each instance pair as a single ***,the smoothness can be pointwise in nature,that is,the smoothness shall inherently occur“everywhere"to relate the behavior of each point or instance to that of its close *** in this paper,we attempt to de-velop a pointwise MR(PW_MR for short)for semi-supervised learning through constraining on individual local *** this way,the pointwise nature of smoothness is preserved,and moreover,by considering individual instances rather than instance pairs,the importance or contribution of individual instances can be *** importance can be described by the confidence for correct prediction,or the local density,for *** provides a different way for implementing manifold smoothness Finally,empirical results show the competitiveness of PW_MR compared to pairwise MR.

关键词： semi-supervised classification manifold regularization pairwise smoothness pointwise smoothness local density

A primal perspective for indefinite kernel SVM problem

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Frontiers of Computer Science 2020年第2期14卷 349-363页

作者： hui xue Haiming XU Xiaohong CHEN Yunyun WANG School of Computer Science and Engineering Southeast UniversityNanjing 210096China Key Laboratory of Computer Network and Information Integration(Southeast University) MOENanjing 210096China College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210046China

Indefinite kernel support vector machine(IKSVM)has recently attracted increasing attentions in machine *** IKSVM essentially is a non-convex problem,existing algorithms either change the spectrum of indefinite kernel directly but risking losing some valuable information or solve the dual form of IKSVM whereas suffering from a dual gap *** this paper,we propose a primal perspective for solving the *** is,we directly focus on the primal form of IKSVM and present a novel algorithm termed as IKSVM-DC for binary and multi-class ***,according to the characteristics of the spectrum for the indefinite kernel matrix,IKSVM-DC decomposes the primal function into the subtraction of two convex functions as a difference of convex functions(DC)*** accelerate convergence rate,IKSVM-DC combines the classical DC algorithm with a line search step along the descent direction at each ***,we construct a multi-class IKSVM model which can classify multiple classes in a unified form.A theoretical analysis is then presented to validate that IKSVM-DC can converge to a local ***,we conduct experiments on both binary and multi-class datasets and the experimental results show that IKSVM-DC is superior to other state-of-the-art IKSVM algorithms.

关键词： indefinite kernel support vector machine multi-class classification non-convex optimization