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A Note on Z_3 -Connected Graphs with Degree Sum Condition

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Acta Mathematica Sinica,English Series 2012年第11期28卷 2161-2168页

作者： Xin min hou Department of Mathematics University of Science and Technology of China

A graph G satisfies the Ore-condition if d（x）＋d（y） ≥ ｜V（G）｜ for any xy E（G）. Luo et al. [European J. Combin., 2008] characterized the simple Z3-connected graphs satisfying the Ore-condition. In this paper, we characterize the simple Z3-connected graphs G satisfying d（x）＋d（y） ≥ ｜V（G）｜ - 1 for any xy E（G）, which improves the results of Luo et al.

关键词： Group connectivity degree sum condition

Peierls-phase-induced topological semimetals in an optical lattice:Moving of Dirac points,anisotropy of Dirac cones,and hidden symmetry protection

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Chinese Physics B 2020年第12期29卷 82-87页

作者： Jing-min hou School of Physics Southeast UniversityNanjing 211189China

We propose a square optical lattice in which some of neighbor hoppings have a Peierls *** Peierls phase makes the lattice have a special band structure and induces the existence of Dirac points in the Brillouin zone,which means that topological semimetals exist in the *** Dirac points move with the change of the Peierls phase and the Dirac cones are anisotropic for some vales of the Peierls *** lattice has a novel hidden symmetry,which is a composite antiunitary symmetry composed of a translation operation,a sublattice exchange,a complex conjugation,and a local U(1)gauge *** prove that the Dirac points are protected by the hidden symmetry and perfectly explain the moving of Dirac points with the change of the Peierls phase based on the hidden symmetry protection.

关键词： topological semimetal optical lattice hidden symmetry

Unconventional Landau Levels of Ultracold Fermionic Atoms on Two-Dimensional Honeycomb Lattice

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Communications in Theoretical Physics 2009年第8期52卷 251-254页

作者： hou Jing-min Department of Physics Southeast University Nanjing 211189 China

We investigate the unconventional Landau levels of ultracold fermionic atoms on the two-dimensionalhoneycomb optical lattice subjected to an effective magnetic field,which is created with optical *** the presenceof the effective magnetic field,the energy spectrum of the unconventional Landau levels is ***,wepropose to detect the unconventional Landau levels with Bragg scattering techniques.

关键词： ultracold atoms honeycomb optical lattice unconventional Landau levels

Unconventional Energy Bands and Chirality of Ultracold Atoms in Trilayer Honeycomb Lattice

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Communications in Theoretical Physics 2009年第8期52卷 247-250页

作者： hou Jing-min Department of Physics Southeast University Nanjing 211189 China

We investigate ultracold fermionic atoms in the trilayer honeycomb lattice. In the low energy approximation, we derive an effective Hamiltonian for pseudospins. The energy spectrum shows a cubic form of the wavevector and is gapless. The quasiparticles and quasiholes are ehiral and show Berry＇s phase π when the wavevector adiabatically evolves along a closed circle, Furthermore, the experimental detection of the energy spectrum is proposed with Bragg scattering techniques.

关键词： ultracold atoms honeycomb optical lattice energy bands

Light-Induced Hofstadter's Butterfly Spectrum in Optical Lattices

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Communications in Theoretical Physics 2009年第3期51卷 441-444页

作者： hou Jing-min Department of Physics Southeast University Nanjing 211189 China

We propose a scheme to create an effective magnetic field, which can be perceived by cold neutral atoms in a two-dimensional optical lattice, with a laser field with a space-dependent phase and a conventional laser field acting on A-type three-level atoms. When the dimensionless parameter a, being the ratio of flux through a lattice cell to one flux quantum, is rational, the energy spectrum shows a fractal band structure, which is so-called Hofstadter＇s butterfly.

关键词： optical lattices cold atoms Hofstadter's butterfly

Codegree Threshold for Tiling k-graphs with Two Edges Sharing Exactly l Vertices

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Acta Mathematica Sinica,English Series 2020年第1期36卷 13-20页

作者： Lei YU Xin min hou Key Laboratory of Wu Wen-Tsun Mathematics School of Mathematical Sciences University of Science and Technology of China

Given integer k and a k-graph F,let t(k-1)(n,F)be the minimum integer t such that every k-graph H on n vertices with codegree at least t contains an *** integers k>3 and 0≤l≤k-1,let y(k,l)be a k-graph with two edges that shares exactly l *** and Zhao(*** Ser.A,(2015))asked the following question:For all k≥3,0≤l≤k-1 and sufficiently large n divisible by 2 k-l,determine the exact value of t_(k-1)(n,y(k,l)).In this paper,we show that t(k-1)(n,y(k,l))=n/(2 k-l)for k>3 and 1≤l≤k-2,combining with two previously known results of R?dl,Rucinski and Szemeredi(*** Ser.A,(2009))and Gao,Han and Zhao(Combinatorics,Probability and Computing,(2019)),the question of Han and Zhao is solved completely.

关键词： Hypergraph codegree factor

Catalytic Elimination of Oxygenated Byproducts in the Toluene Methylation Process

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China Petroleum Processing & Petrochemical Technology 2023年第2期25卷 65-73页

作者： hou min Qi Xiaolan Zheng Junlin State Key Laboratory of Green Chemical Engineering and Industrial Catalysis SINOPEC Shanghai Research Institute of Petrochemical Technology Co.Ltd.Shanghai 201208China

Catalytic methylation of toluene with methanol is an important alternative pathway for xylene *** studies have indicated that methanol always undergoes several side reactions on acidic zeolites,resulting in oxygencontaining byproducts such as dimethyl ethers,ketones,and carboxylic ***,the presence and distribution of the oxygenated compounds formed during toluene methylation were firstly examined by systematic chromatographic *** formation mechanisms for the various oxygenates are *** most problematic byproduct is found to be acetic acid,which can lead to inferior product quality and damage downstream units.A feasible solution is presented for oxygenate removal after toluene methylation,in which acetic acid is eliminated by catalytic decomposition into low-boilingpoint acetone over a MgO *** process allows for all of the low-boiling-point oxygenates,including methanol,dimethyl ether,acetone,and butanone,to be removed from the aromatics phase,taking advantage of the temperature of the reaction effluent and standard distillation equipment.X-ray diffraction was used to characterize the crystal phase of the fresh and used MgO decarbonylation catalysts,while thermogravimetry/mass spectrometry and Fourier-transform infrared spectroscopy were applied to investigate the transformation mechanism of acetic acid over the decarbonylation *** insertion and ketonization of acetic acid accounted for the formation and elimination of acetic acid,*** combined methylation/decarbonylation process should enable the production of high-quality xylenes,an important industrial feedstock,by overcoming the main technical obstacles associated with the toluene methylation process.

关键词： xylene catalytic methylation decarbonylation toluene MgO catalyst

Hidden antiunitary symmetry behind ＂accidental＂ degeneracy and its protection of degeneracy

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Frontiers of physics 2018年第1期13卷 211-214页

作者： Jing-min hou Wei Chen School of Physics Southeast University Nanjing 211189 China College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

In quantum mechanics, accidental degeneracy refers to energy degeneracy that occurs coincidentally, without any protection by symmetry. Here, we prove a theorem stating that any two-fold degeneracy （accidental or not） in a quantum system is protected by a novel hidden symmetry, which can be expressed by an antiunitary operator with its square being -1. In this sense, the so-called accidental degeneracy is not really accidental, and this actually implies a hidden antiunitary symmetry.

关键词： accidental degeneracy hidden symmetry antiunitary symmetry

Neodymium-catalyzed Polymerization of C5 Fraction: Efficient Synthesis of 1,3-Pentadiene-isoprene Copolymer Rubbers

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Chinese Journal of Polymer Science 2019年第7期37卷 674-680页

作者： Jin-Yan hou Fang Guo Qian Hu Yang Li Zhao-min hou State Key Laboratory of Fine Chemicals Department of Polymer Science and EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116012China Fushun Yikesi New Material Co. Ltd.Fushun 113000China Advanced Catalysis Research Group RIKEN Center for Sustainable Resource Science2-1 HirosawaWakoSaitama 351-0198Japan

The polymerization of C5 fraction without separation and concentration by using a commercial available Nd(P204)3/ AliBu3/AlEt2Cl has afforded for the first time a new kind of 1,3-pentadiene-isoprene random copolymers as rubber materials. Isoprene (IP) and E-1,3-pentadiene (EPD) acted as polymerization monomers, cyclopentadiene acted as poison, and other substances like alkanes, monoolefins, Z-1,3-pentadiene acted as solvents in this multicomponent C5 fraction polymerization system. The data of kinetic experiments, NMR, and DSC indicated that the polymerization of C5 fraction by Nd(P204)3/AliBu3/AlEt2Cl afforded the IP-EPD random copolymers. By controlling polymerization conditions such as [Al]/[Nd]/[Cl] molar ratio and polymerization temperature, the random EPD-IP copolymers containing high cis-1,4-poly(IP)(with selectivity 96%) and moderate cis-1,4-poly(EPD)(with selectivity 60%) units with a low glass transition temperature (about 60 ℃), controllable molecular weight (Mn = 3.8 × 10^4-14.3 × 104), and moderate molecular weight distribution (Mw/Mn = 2.17-2.78) were obtained in a high yield.

关键词： C5 fraction Neodymium Isoprene 1,3-Pentadiene Copolymerization