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色氨酸系统的保稳定性非凸优化模型与几何规划算法

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数学的实践与认识 2025年第1期55卷 147-157页

作者：岳美伯徐恭贤冯爽渤海大学数学科学学院辽宁锦州121013

研究了色氨酸系统的优化问题.给出了色氨酸系统的非线性数学模型,并论述了模型的数学性质.以最大化色氨酸产率为优化目标构建了色氨酸系统的非凸保稳定性优化模型,该模型能够保证色氨酸系统在最优且稳定的稳态下工作.基于等价变换与单... 详细信息

研究了色氨酸系统的优化问题.给出了色氨酸系统的非线性数学模型,并论述了模型的数学性质.以最大化色氨酸产率为优化目标构建了色氨酸系统的非凸保稳定性优化模型,该模型能够保证色氨酸系统在最优且稳定的稳态下工作.基于等价变换与单项式补偿策略提出了一种可以快速求解非凸保稳定性优化模型的几何规划算法,并给出了算法的收敛性分析.计算结果表明本文所提几何规划算法是有效的.

关键词：色氨酸系统几何规划优化算法保稳定性

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Odd-even staggering for production cross sections of nuclei near the neutron drip-line

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Chinese Physics C 2021年第8期45卷 139-144页

作者： bo mei Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

In our previous studies[***.C 97,044619(2018);***.C 103,044610(2021)],a universal odd-even staggering(OES)has been observed in extensive cross sections of isotopes not far from stability,measured for different fragmentation and spallation *** OES relations have been proposed on the basis of this OES ***,it is still unclear whether this OES universality and OES relations are applicable to many isotopes near the ***,the OES in recent experimental cross sections of very neutron-rich nuclei approaching the drip-line(from ^(76)Ge,^(82)Se+^(9)Be)is quantitatively investigated,to further validate the OES universality and OES *** OES magnitudes in these experimental data approaching the neutron drip-line generally agree with those evaluated previously,mainly from experimental data near *** OES evaluations de-rived from these experimental data are also recommended for more exotic nuclei near the neutron drip-line,which extends the conclusions of our previous OES *** addition,the OES relation calculations are consistent with these experimental data of very neutron-rich nuclides according to their comparisons in this ***,comparisons with additional experimental data(from ^(238)U+^(9)Be)also support that new OES evaluations and OES relation calculations can be applied for exotic nuclei near the neutron drip-line.

关键词： fragmentation and spallation reactions cross sections of neutron-rich nuclei odd-even staggering

Modeling Kinetics of Deformation Induced Ferrite Transformation in Fe-C-Mn Alloy

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Journal of Iron and Steel Research International 2005年第2期12卷 49-51页

作者： XUYun-bo YUYong-mei LIUXianghua WANGGuo-dong NortheasternUniversity Shenyang110004China

The influence of hot deformation on the incubation period of ferrite transformation was calculated to determine the onset of deformation induced transformation. Temperature A r3d depends on deformation condition and alloying composition, and decreases with increasing carbon content. When deformation induced ferrite transformation occurs, the flow curves of dislocation density will show strong softening characteristic. Through temperature heavy deformation, ferrite transformation is enhanced and more volume fraction is obtained. The simulated results are in good agreement with the experiment ones.

关键词： dislocation density Fe-C-Mn alloy ultra-fine steel low temperature heavy deformation

Tight sandstone gas accumulation mechanisms and sweet spot prediction, Triassic Xujiahe Formation, Sichuan Basin, China

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Petroleum Science 2023年第6期20卷 3301-3310页

作者： Lin Jiang Wen Zhao Dong-mei bo Feng Hong Yan-Jie Gong Jia-Qing Hao Research Institute of Petroleum Exploration and Development PetroChinaBeijing100083China

The prediction of continental tight sandstone gas sweet spots is an obstacle during tight sandstone gas exploration. In this work, the classic physical fluid charging experimental equipment is improved, the combination of the gas migration and accumulation process with the pore network numerical simulation method is investigated, and application of the permeability/porosity ratio is proposed to predict the gas saturation and sweet spots of continental formations. The results show that (1) as the charging pressure increases, the permeability of the reservoir increases because more narrow pore throats are displaced in the percolation process;and (2) based on pore network numerical simulation and theoretical analysis, the natural gas migration and accumulation mechanisms are revealed. The gas saturation of tight sandstone rock is controlled by the gas charging pressure and dynamic percolation characteristics. (3) The ratio of permeability/porosity and fluid charging pressure is proposed to predict the gas saturation of the formation. The ratio is verified in a pilot and proven to be applicable and practical. This work highlights the tight sandstone gas migration and accumulation mechanisms and narrows the gap among microscale physical experiments, numerical simulation research, and field applications.

关键词： Tight sandstone gas Hydrocarbon migration and accumulation Physical experiment Numerical simulation

Prediction of Rolling Load, Recrystallization Kinetics, and Microstructure During Hot Strip Rolling

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Journal of Iron and Steel Research International 2007年第6期14卷 42-46页

作者： XU Yun-bo YU Yong mei LIU Xiang-hua WANG Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

The recrystallization kinetics and grain size models were developed for the C Mn and niobium containing steels to describe the metallurgical phenomenon such as softening, grain growth, and strain accumulation. Based on the recrystallization kinetics equations, the mean flow stress and the rolling load of each pass were predicted and the optimum rolling schedule was proposed for hot strip rolling. The austenite grain refinement is associated with the addition of niobium, the decrease of starting temperature of finish rolling, and the reduction of finished thickness. The mean flow stress curve with a continuous rising characteristic can be usually observed in the finish rolling of niobium containing steel, which is formed as a result of the heavy incomplete softening and strain accumulation. The predic ted rolling loads are in good agreement with the measured ones.

关键词： hot strip rolling recrystallization mean flow stress strain accumulation grain size

Computer Model of Phase Transformation From Hot-Deformed Austenite in Niobium Microalloyed Steels

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Journal of Iron and Steel Research International 2007年第2期14卷 66-69页

作者： XU Yun-bo YU Yong-mei LIU Xiang-hua WANG Guo-dong State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Based on thermodynamics and kinetics, a new mathematical model was developed to calculate the CCT diagrams and the transformation kinetics in low carbon niobium steels, in which the effect of deformation on the degree of supercooling was taken into account. The undercooling caused by deformation is the major reason for the increase of the starting transition temperature during continuous cooling. The critical cooling rate of bainite formation is within 2--5 ℃s for the studied niobium steels and deformation is suitable for the occurrence of pearlite. The ferrite volume fraction increases with the increase of the austenite boundary area, and decreases with the increase of the cooling rate. The calculated CCT diagrams and the volume fraction of each phase are in good agreement with the measurements.

关键词： low carbon niobium steel thermodynamics supercooling degree continuous cooling transformation computer model

Analysis of a Critical Residue Determining Herbicide Efficiency Sensitivity in Carboxyltransferase Domain of Acetyl-CoA Carboxylase from Poaceae by Homology Modeling and Free Energy Simulation

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Chemical Research in Chinese Universities 2010年第5期26卷 816-821页

作者： TAO Jin ZHAO bo TIAN Xue-mei ZHENG Liang-yu CAO Shu-gui Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education Jilin University Changchun 130021 P. R. China

Carboxyltransferase domain（CT） of acetyl-coenzyme A carboxylase（ACCase, EC 6.***.1.2） from a family of Poaceae is an important target of commercial herbicide APPs for controlling grass weed growth. As the abuse of APPs herbicides, the resistant ACCase due to the mutation of a single residue（Ile→Leu）, which is located in CT active site, is emergent in many populations and species of Poaceae. So it is urgent to understand the resistant mechanism so as to design new effect herbicides. Herein lies the complex of CT dimmer from Lolium rigidum and herbicide haloxyfop successfully constructed for wild type enzyme and Ile/Leu mutant, respectively, providing a basis for explaining the resistance from microscopic structure. Moreover, the binding free energy difference between wild type and mutant enzymes was predicted in good agreement with the known observation, and the various contributions to it were analyzed, by Molecular mechanics-Poisson-boltzmann surface area（MM-PBSA） method. The results indicate the van der Waals interaction difference between the protein and inhibitor, -22.94 kJ/mol of CT wild type lower than that of mutant, is the major reason for resistance. Structure analysis further suggests that van der Waals interaction difference is originated from the steric hindrance between the side chain of mutated residue Leu and the chiral methyl group of haloxyfop. All these findings enhance the understanding of resistant mechanism of ACCase to herbicide by Ile/Leu mutation and provide an important clue for the rational design of high effective herbicides.

关键词： Molecular modeling Molecular dynamics Free energy calculation Herbicide resistance

Thermodynamic Calculation of Carbide Precipitate in Niobium Microalloyed Steels

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Journal of Iron and Steel Research International 2006年第6期13卷 53-56页

作者： XU Yun-bo YU Yong-mei LIU Xiang-hua WANG Guo-dong State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

On the basis of regular solution sublattice model, thermodynamic equilibrium of austenite/carbide in Fe-Nb-C ternary system was investigated. The equilibrium volume fraction, chemical driving force of carbide precipitates and molar fraction of niobium and carbon in solution at different temperatures were evaluated respectively. The volume fraction of precipitates increases, molar fraction of niobium dissolved in austenite decreases and molar fraction of carbon increases with decreasing the niobium content. The driving force increases with the decrease of temperature, and then comes to be stable at relatively low temperatures. The predicted ratio of carbon in precipitates is in good agreement with the measured one.

关键词： microalloyed steel thermodynamic calculation phase equilibrium carbide prediction model

Excellent Glass Forming Ability and Refrigeration Capacity of a Gd_(55)Al_(2)0Ni_(12)Co_(10)Mn_(3)Bulk Metallic Glass

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Chinese Physics Letters 2013年第9期30卷 105-108页

作者： DING Ding WANG Peng GUAN Quan TANG mei-bo XIA Lei Laboratory for Microstructure Shanghai UniversityShanghai 200072 Key Laboratory of Transparent and Opto-functional Inorganic Materials Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050

We investigate an excellent refrigeration capacity𝑆Rc𝑑of Gd_(55)Al_(20)Ni_(12)Co_(10)Mn_(3)bulk metallic glass(BMG).The Gd_(55)Al_(20)Ni_(12)Co_(10)Mn_(3)glassy rod is subjected to Cu mold suction-casting to prepare bulky metallic glasses,with a diameter of *** glass forming ability as well as the magnetic properties of the BMG is *** BMG exhibits a rather high glass formation ability with critical diameter of about *** peak value of magnetic entropy change of about 8J·kg^(−1)K^(−1)is obtained in this *** BMG alloy also exhibits excellent magnetic refrigerant capacity of about 880J·kg^(−1)under the field of 5T and 35%larger than that of other alloys reported previously,supposed to be closely related to the high effective moment(∼7.3μB)of the Gd 55 Al_(20)Ni_(12)Co_(10)Mn_(3)BMG.

关键词： alloy casting alloys