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Min-max partitioning problem with matroid constraint

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1446-1450页

作者： biao WU En-yu YAO Department of Mathematics Zhejiang University Hangzhou 310027 China

In this paper, we consider the set partitioning problem with matroid constraint, which is a generation of the k-partitioning problem. The objective is to minimize the weight of the heaviest subset. We present an approximation algorithm, which consists of two sub-algorithms-the modified Edmonds' matroid partitioning algorithm and the exchange algorithm, for the problem. An estimation of the worst ratio for the algorithm is given.

关键词： Matroid Matroid partition Worst ratio

Quantum Teleportation and Superdense Coding via W-Class States

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Communications in Theoretical Physics 2008年第4期49卷 901-904页

作者： WU Huai-Zhi YANG Zhen-biao ZHENG Shi-biao Department of Electronic Science and Applied Physics Fuzhou University Fuzhou 350002 China

Abstract According to the protocol of Agrawal et al., we propose a cavity QED scheme for realization of teleportation and dense coding. Instead of using EPR states and GHZ states, our scheme is more insensitive to the loss of one particle by using a W-class state as a quantum channel. Besides, our scheme is immune to thermal field, and does not require the cavity to remain in the vacuum state throughout the procedure.

关键词： W-class states teleportation dense coding

Ehrenfest Time at the Transition from Integrable Motion to Chaotic Motion

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Chinese Physics Letters 2021年第3期38卷 29-32页

作者： Chuan Zhao biao Wu International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Wilczek Quantum Center School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of Quantum Matter Beijing 100871China

Ehrenfest time depends differently on the Planck constant in integrable motion and chaotic motion. We study how its dependence on the Planck constant changes when there is a continuous transition from regular motion to chaotic motion. We find that the dependence is a weighted compromise between its two distinct dependences in regular and chaotic motions. The study is carried out with the system of periodically driven anharmonic oscillator. As the system is quite typical, the result may apply generally.

关键词： motion. chaotic system

Crystallization Kinetics Study on Magnetron-Sputtered Amorphous TiA1 Alloy Thin Films

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Chinese Physics Letters 2014年第4期31卷 100-104页

作者： SHUI Lu-Yu YAN biao School of Materials Science and Engineering Tongji University Shanghai 201804 Shanghai Key Lab of D&A for Metal-Functional Materials Shanghai 201804

Crystallization kinetics of magnetron-sputtered amorphous TiAl ahoy thin films is investigated by differential scanning calorimetry through isothermal analysis and non-isotherm analysis. In non-isothermai analysis, the Kissinger method and the Ozawa method are used to calculate the apparent activation energy and local activation energy, respectively, in the crystallization processes of amorphous TiA1 thin films. Furthermore, the crystallization mechanism is discussed from the investigation of the A vrami exponent by isothermal analysis. In addition, x-ray diffraction is utilized to reveal the grain orientation and evolution during the crystallization of TiA1 thin fihns.

关键词： Films Crystallization Kissinger

The Maximum Lagrangian of 5-uniform Hypergraphs without Containing Two Edges Intersecting at a Vertex

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Acta Mathematica Sinica,English Series 2022年第5期38卷 877-889页

作者： biao WU Yue Jian PENG MOE-LCSM School of Mathematics and StatisticsHu’nan Normal UniversityChangsha 410081P.R.China School of Mathematics Hu’nan UniversityChangsha 410082P.R.China

Obtaining Turán densities of hypergraph through determining Lagrangian densities have been studied *** showed that the Lagrangian density of an r-uniform hypergraph equals the Turán density of the extension of this ***,Lagrangian density and Turán density are the same for a large class of hypergraphs such as hypergraphs covering *** Pr,sbe the r-uniform hypergraph with two edges intersecting at s *** determined the Lagrangian densities of Pr,sfor r=3 and s=1 or 2,or r=4 and s=2 or *** and Keevash determined for r=3 and s=0,and Bene Watts,Norin and Yepremyan determined for r≥4 and s=*** cases r=5 and s=4 or r=6 and s=5 were determined by Norin and *** showed for r=5,6 or 7,and s=3,4 or 5 *** cases r=4 and s=1 or r=5 and s=2 were determined by Jiang,Peng and Wu,and Hu,Peng and Wu *** r=5,the only remaining case is s=*** this paper,we determine for this case.

关键词： Hypergraph Lagrangian Turán number

Lagrangian-based investigation of the transient flow structures around a pitching hydrofoil

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Acta Mechanica Sinica 2016年第1期32卷 64-74页

作者： Qin Wu biao Huang Guoyu Wang School of Mechanical and Vechicular Engineering Beijing Institute of Technology

The objective of this paper is to address the transient flow structures around a pitching hydrofoil by com- bining physical and numerical studies. In order to predict the dynamic behavior of the flow structure effectively, the Lagrangian coherent structures （LCS） defined by the ridges of the finite-time Lyapunov exponent （FTLE） are utilized under the framework of Navier-Stokes flow computations. In the numerical simulations, the k-w shear stress trans- port （SST） turbulence model, coupled with a two-equation F-Reo transition model, is used for the turbulence closure. Results are presented for a NACA66 hydrofoil undergoing slowly and rapidly pitching motions from 0° to 15° then back to 0° at a moderate Reynolds number Re = 7.5 × 105. The results reveal that the transient flow structures can be observed by the LCS method. For the slowly pitching case, it consists of five stages： quasi-steady and laminar, transition from laminar to turbulent, vortex development, large-scale vortex shedding, and reverting to laminar. The observation of LCS and Lagrangian particle tracers elucidates that the trailing edge vortex is nearly attached and stable during the vortex development stage and the interaction between the leading and trailing edge vortex caused by the adverse pres- sure gradient forces the vortexes to shed downstream during the large-scale vortex shedding stage, which corresponds to obvious fluctuations of the hydrodynamic response. For the rapidly pitching case, the inflection is hardly to be observed and the stall is delayed. The vortex formation, interaction, and shedding occurred once instead of being repeated three times, which is responsible for just one fluctuation in the hydrody- namic characteristics. The numerical results also show that the FTLE field has the potential to identify the transient flows, and the LCS can represent the divergence extent of infinite neighboring particles and capture the interface of the vortex region.

关键词： Transient flow structure Pitching hydrofoilFinite-time Lyapunov exponent Lagrangian coherentstructures

An improved artificial bee colony algorithm for steelmaking–refining–continuous casting scheduling problem

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1727-1735页

作者： Kunkun Peng Quanke Pan biao Zhang State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology

Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. This paper develops an Improved Artificial Bee Colony(IABC) algorithm for the SCC scheduling. In the proposed IABC, charge permutation is employed to represent the solutions. In the population initialization, several solutions with certain quality are produced by a heuristic while others are generated randomly. Two variable neighborhood search neighborhood operators are devised to generate new high-quality solutions for the employed bee and onlooker bee phases, respectively. Meanwhile, in order to enhance the exploitation ability, a control parameter is introduced to conduct the search of onlooker bee phase. Moreover, to enhance the exploration ability,the new generated solutions are accepted with a control acceptance criterion. In the scout bee phase, the solution corresponding to a scout bee is updated by performing three swap operators and three insert operators with equal probability. Computational comparisons against several recent algorithms and a state-of-the-art SCC scheduling algorithm have demonstrated the strength and superiority of the IABC.

关键词： Artificial bee colony Steelmaking–refining–continuous casting Hybrid flowshop scheduling Variable neighborhood search

Supercritical CO2 Assisted Preparation of Open-cell Foams of Linear Low-density Polyethylene and Linear Low-density Polyethylene/Carbon Nanotube Composites

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Chinese Journal of Polymer Science 2016年第7期34卷 889-900页

作者： jia wang 张利 jin-biao bao Ningbo Key Laboratory of Specialty Polymers Faculty of Materials Science and Chemical Engineering Ningbo University Ningbo 315211 China

The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxide（sc-CO2）as a foaming agent. The effects of processing parameters（foaming temperature, saturation pressure, and depressurization rate） and the addition of MWCNTs on the evolution of cell opening are studied systematically. For LLDPE foaming, the foaming temperature and saturation pressure are two key factors for preparing open-cell foams. An increase in temperature and pressure promotes both the cell wall thinning and cell rupture, because a high temperature results in a decrease in the viscosity of the polymer, and a high pressure leads to a larger amount of cell nucleation. Moreover, for the given temperature and pressure, the high pressurization rate results in a high pressure gradient, favoring cell rupture. For LLDPE/MWCNTs foaming, the addition of MWCNTs not only promotes the cell heterogeneous nucleation, but also prevents the cell collapse during cell opening, which is critical to achieve the open-cell structures with small cell size and high cell density.

关键词： Linear low-density polyethylene MWCNTs Supercritical carbon dioxide Foam Open-cell morphologies

Advancements in animal nutrition: The interplay of feed enzymes, gut health, and nutrient supply in poultry and pig production——A tribute to Professor Mingan Choct's 30-year scientific legacy

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Animal Nutrition 2024年第2期17卷 373-375页

作者： Shu-biao Wu School of Environmental and Rural Science University of New England

Animal production is a significant protein source for human consumption(Salter and Lopez-Viso, 2021). The production of monogastric animals has grown enormously in recent decades,particularly of poultry and swine(Rauw et al., 2020). Such growth is attributed to the progress in animal nutrition, disease control,and genetic improvement in response to the global demand for meat(Kumar et al., 2023) and, of course, the tireless efforts of scientists working in the area for the past decades. Among them is Professor Mingan Choct, a monogastric animal nutritionist at the University of New England. He has dedicated his entire academic career to the field, significantly contributing to monogastric animal research and industry. To honour his contribution and celebrate his retirement, we organized a special issue in Animal Nutrition with contributions from a group of prominent researchers in monogastric animal nutrition and health. In this special issue, we published reviews and research papers, 8 in total, with a focus on the nutrition and health of monogastric production animals.

关键词： professor nutrition legacy nutrient supply feed 30-year advancements animal choct