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Numerical analysis for the matching of the core driven compression system in a double bypass engine

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航空动力学报 2011年第5期26卷 1066-1076页

作者： ZHANG xin LIU Bao-jie National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this *** system consists of a one-stage-core driven fan stage(CDFS),an inner bypass duct and a five-stage high pressure compressor(HPC),providing two basic operating modes: the single bypass mode and the double bypass *** vanes are necessary to realize the mode switch of the *** correct matching in the double bypass mode requires a proper combination of the mass flow,total pressure ratio and blade *** work capacity of the system decreases in the double bypass mode and the pressure ratio tends to decrease more for the CDFS and the front stages of the *** overall system efficiency is higher in the double bypass *** radial distributions of aerodynamic parameters are similar in different *** notable redistribution of mass flow downstream the CDFS in the single bypass mode leads to strong radial flows and additional mixing *** absolute flow angles into the inner bypass increase for the inner span and decrease for the outer span when the system is switched from the single bypass mode to the double bypass mode.

关键词： numerical analysis aerodynamic double bypass variable cycle engine core driven compression system core driven fan stage operating mode

Temperature Rise at the Edges of Dark Molecular Clouds

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Chinese Physics Letters 2000年第1期17卷 67-69页

作者： MAO xin-jie Astronomy Department Beijing Normal UniversityBeijing 100875 Chinese Academy of Sciences-Peking University Joint Beijing Astrophysical Center Peking UniversityBeijing 100871

Two-fluid magnetohydrodynamic equations are applied to dark molecular clouds that are composed of neutrals mixed with minor charged particles,weakly ionized gas *** result shows the temperatures are higher at the cloud edges than at their inner regions,the cause of which is that the cloud potential,released as clouds contract particularly at their edges,along with some dissipated rotational kinetic energy is converted into *** cloud contracting is due to the loss of the magnetic field that threads it through ambipolar ***,without the support of the magnetic and the centrifugal forces in the direction of the magnetic Held assumed to be parallel to the cloud rotating axis,the cloud collapses in that direction when its mass is over the Jeans mass.

关键词： rotating systems. assumed

Interactive multiobjective evolutionary algorithm based on decomposition and compression

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Science China(Information Sciences) 2021年第10期64卷 166-181页

作者： Lu CHEN Bin xin jie CHEN School of Automation Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex Systems

Many real-world optimization problems involve multiple conflicting objectives. Such problems are called multiobjective optimization problems(MOPs). Typically, MOPs have a set of so-called Pareto optimal solutions rather than one unique optimal solution. To assist the decision maker(DM) in finding his/her most preferred solution, we propose an interactive multiobjective evolutionary algorithm(MOEA)called iDMOEA-εC, which utilizes the DM’s preferences to compress the objective space directly and progressively for identifying the DM’s preferred region. The proposed algorithm employs a state-of-the-art decomposition-based MOEA called DMOEA-εC as the search engine to search for solutions. DMOEA-εC decomposes an MOP into a series of scalar constrained subproblems using a set of evenly distributed upper bound vectors to approximate the entire Pareto front. To guide the population toward only the DM’s preferred part on the Pareto front, an adaptive adjustment mechanism of the upper bound vectors and two-level feasibility rules are proposed and integrated into DMOEA-εC to control the spread of the population. To ease the DM’s burden, only a small set of representative solutions is presented in each interaction to the DM,who is expected to specify a preferred one from the set. Furthermore, the proposed algorithm includes a two-stage selection procedure, allowing to elicit the DM’s preferences as accurately as possible. To evaluate the performance of the proposed algorithm, it was compared with other interactive MOEAs in a series of experiments. The experimental results demonstrated the superiority of iDMOEA-εC over its competitors.

关键词： multiobjective optimization interactive decision making preference incorporation decomposition compression

Influence of mill modulus control gain on vibration in hot rolling mills

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Journal of Iron and Steel Research International 2020年第5期27卷 528-536页

作者： jie-bin Qi xin-xin Wang Xiao-qiang Yan School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Research Institute of Technology Shougang Group Co.Ltd.Beijing 100043China

The rolling mill vibration is characterized by the coupling effects among mechanical,electrical,hydraulic and interfacial *** influence of the mill modulus control gain in automatic gauge control on the vibration in hot rolling mills was ***,an experiment related to the mill modulus control gain was carried out in the hot rolling mill process,and it was found that the rolling mill vibration increases with the mill modulus control ***,based on the Sims rolling force method,the coupling dynamic model was established to explain this ***,the influence of mill modulus control gain on the vibration was analyzed numerically on the basis of the coupling dynamic ***,the agreement between the experimental results and the simulation results was confirmed and the measure reducing the mill modulus control gain was obtained to relieve mill vibration.

关键词： Rolling mill vibration Coupling dynamic model Automatic gauge control Mill modulus control gain Vibration suppression

Strong Edge Coloring of Outerplane Graphs with Independent Crossings

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 467-477页

作者： Ke-jie LI xin ZHANG School of Mathematics and Statistics Xidian UniversityXi’an 710071China

The strong chromatic index of a graph is the minimum number of colors needed in a proper edge coloring so that no edge is adjacent to two edges of the same *** outerplane graph with independent crossings is a graph embedded in the plane in such a way that all vertices are on the outer face and two pairs of crossing edges share no common end *** is proved that every outerplane graph with independent crossings and maximum degreeΔhas strong chromatic index at most 4Δ-6 if Δ≥4,and at most 8 ifΔ≤*** bounds are sharp.

关键词： outer-1-planar graph IC-planar graph strong edge coloring crossing

二氢杨梅素分子结构与性质的密度泛函理论研究

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原子与分子物理学报 2025年第1期42卷 29-34页

作者：辛国鹏毛敏刘信平马文涛马杰张煜湖北民族大学化学与环境工程学院恩施445000

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H... 详细信息

本文基于密度泛函理论(DFT),采用B3LYP泛函结合6-31G基组上对二氢杨梅素的分子几何结构进行了优化,在此基础上以水为溶剂计算二氢杨梅素分子的活性位点以及红外光谱进行分析.静电势结果表明二氢杨梅素的亲核活性位点位于酚羟基氢原子(H23)附近;而亲电活性位点位于氧原子(O32)及其附近.前线分子轨道研究结果表明二氢杨梅素分子的最高占据轨道(HOMO)都位于酮基氧(O32)和羟基氧(O20)附近,说明这些位点易与亲电试剂反应.而最低空轨道(LUMO)位于碳原子(C12、C13、C14)区域,表明这些区域可与亲核试剂反应.简缩福井函数(f)结果证实了位于C-O-C键中的氧原子的f-值的亲电活性较其他位点氧原子大;而位于C8碳原子的f^(+)值较大,因此该位点亲核活性较强.通过理论计算所得到的二氢杨梅素的红外光谱数据与实验所得到的红外光谱数据相差不大,这就说明理论计算结果是较为可靠的.从而为实验和理论研究二氢杨梅素结构与性质的关系提供了一定的理论参考.

关键词：二氢杨梅素密度泛函理论反应活性位点量子化学计算

An active method suppressing rolling mill vibration: disturbance estimation and compensation algorithm

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Journal of Iron and Steel Research International 2019年第7期26卷 697-703页

作者： Xiao-qiang Yan jie-bin Qi xin-xin Wang School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083 China

The rolling mill vibration not only seriously causes the strip thickness heterogeneity, but also damages the rolling mill equipment and its electrical components. Existing vibration suppression methods are passive and mainly tune mechanical, hydraulic, electrical and rolling process parameters. A new active vibration suppression method was thus proposed using the disturbance estimation and compensation algorithm. Firstly, the hydraulic-mechanical coupling model of the rolling mill vibration was established, and an active vibration suppressor was designed based on the extended state observer. Then, through the numerical simulation, it is found that the vibration energy is reduced by 35.3% using the vibration suppressor, and the vibration suppressor is valid when the vibration frequency is lower than 60 Hz Finally, the vibration suppressor was applied to the in-site manufacturing, and the expected vibration suppression was obtained. The method makes the produced steel strip have more uniform thickness and further significantly increases the finished product ratio.

关键词： Rolling mill vibration Active vibration suppression Disturbance estimation Compensation algorithm Extended state observer

In-situ Observation of Point Defect and Precipitate Evolvement of CLAM Steel under Electron Irradiation

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Journal of Materials Science & Technology 2013年第5期29卷 467-470页

作者： Yong xin Tongda Ma xin Ju jie Qiu Department of Physics University of Science and Technology Beijing General Research Institute for Nonferrous Metals Institute of Nuclear and New Energy Technology Tsinghua University

The point defect and precipitate evolution of China low activation martensitic steel （CLAM） under electron beam irradiation were characterized by high voltage electron microscopy. The process was recorded in-situ on electronsensitive films. The irradiation dose rate was 1.78 × 10-3 dpa/s and the highest dose was 2.12 dpa/s. Irradiation introduced dislocation loops into the sub-grain, which increased density when the irradiation dose was increased from 0.53 dpa to 1.59 dpa at 723 K. The precipitate, found to be an M6C type, was irradiated at 773 K at the [011] plane direction. The precipitate morphology and structure were unchanged when the irradiation dose was increased to 2.12 dpa. Compared with the irradiation at 723 K in the sub-grain, no other defects were generated at the nearby grain boundary at 773 K.

关键词： Martensitic steel Electron microscopy Electron irradiation Defect Precipitate

Multi-Objective Cooperative Salvo Attack Against Group Target

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Journal of Systems Science & Complexity 2018年第1期31卷 244-261页

作者： ZENG jie DOU Lihua xin Bin School of Automation State Key Laboratory of Intelligent Control and Decision of Complex SystemsBeijing Advanced Innovation Center for Intelligent Robots and Systems Beijing Institute of Technology

This paper proposes a solution for the problem of cooperative salvo attack of multiple cruise missiles against targets in a group. Synchronization of the arrival time of missiles to hit their common target, minimizing the time consumption of attack and maximizing the expected damage to group targets are taken into consideration simultaneously. These operational objectives result in a hierarchical mixed-variable optimization problem which includes two types of subproblems, namely the multi-objective missile-target assignment（MOMTA） problem at the upper level and the time-optimal coordinated path planning（TOCPP） problems at the lower level. In order to solve the challenging problem, a recently proposed coordinated path planning method is employed to solve the TOCPP problems to achieve the soonest salvo attack against each target. With the aim of finding a more competent solver for MOMTA, three state-of-the-art multi-objective optimization methods（MOMs）,namely NSGA-II, MOEA/D and DMOEA-εC, are adopted. Finally, a typical example is used to demonstrate the advantage of the proposed method. A simple rule-based method is also employed for comparison. Comparative results show that DMOEA-εC is the best choice among the three MOMs for solving the MOMTA problem. The combination of DMOEA-εC for MOMTA and the coordinated path planning method for TOCPP can generate obviously better salvo attack schemes than the rule-based method.

关键词： Coordinated path planning missile-target assignment multi-missile salvo attack multiobjective optimization