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MARKETING OBJECTIVES OF RETAILERS WITH DIFFERENTIATED GOODS:AN EVOLUTIONARY PERSPECTIVE

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Journal of Systems Science and Systems Engineering 2006年第3期15卷 359-374页

作者： Tiaojun xiao gang YU School of Management Science and Engineering Nanjing University Nanjing Jiangsu 210093 China Department of Management Science and Information Systems McCombs School of Business The University of Texas at Austin Austin Texas 78712-1175 USA

In the real world, revenue maximization behavior may prevail in various markets. To understand this phenomenon, we develop a two-population model with two-vertically integrated channels. Every channel consists of one manufacturer and many （a sufficiently large number of） retailers that sell products in different markets by adopting pure marketing objective strategies： profit maximization and revenue maximization. We study the marketing objective behaviors in the quantity-setting duopoly and the price-setting duopoly situations respectively from an indirect evolutionary point of view. In the quantity-setting duopoly situation, we find that whether the equilibrium is an evolutionarily stable strategy depends on the type of strategic iateraction （substitutes or complements）, relative unit cost, market scale, etc. We extend it to the case with continuous preferences. We argue that revenue maximization may be an evolutionarily stable strategy and profit maximization strategy may be unstable. Under proper conditions, revenue maximization behavior can coexist with profit maximization behavior. In the price-setting duopoly situation with linear demand functions, we find that profit maximization is always an evolutionarily stable strategy and revenue maximization behavior will gradually become extinct. The extended model has a similar result but the retailers may compromise the two pure strategies.

关键词： Evolutionary game theory ESS marketing objective complements and substitutes

A New Understanding of Stress Corrosion Cracking Mechanism of X80 Pipeline Steel at Passive Potential in High-pH Solutions

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Acta Metallurgica Sinica(English Letters) 2015年第7期28卷 866-875页

作者： Lin Fan Zhi-Yong Liu Wei-Min guo Jian Hou Cui-Wei Du xiao-gang Li Corrosion and Protection Center University of Science and Technology Beijing State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research Institute

Susceptibilities to stress corrosion cracking（SCC） of X80 pipeline steel in relatively concentrated carbonate/bicarbonate solutions with different chloride ion concentrations or p H value at a passive potential of-200 m V vs SCE were investigated by slow strain rate tensile *** order to explore the SCC mechanism and the evaluation criterion for the SCC susceptibility of the steel in passive state,electrochemical measurements were *** polarization curves were obtained at different potential sweep rates,and electrochemical impedance spectroscopy measurements were taken after fast polarization to the passive *** effects of chloride ion and p H on SCC behaviors of X80 steel at the passive potential were also *** results showed that the SCC mechanism of X80 pipeline steel was greatly influenced by the passive film formed in these *** SCC behaviors followed the film suppressed anodic dissolution mechanism in these circumstances,because the filming process accounted for a considerable proportion of the overall electrode *** criteria for evaluating the SCC susceptibility of the steel at passive potential were proposed and *** in the concentration of chloride ion or increasing in p H value resulted in the reduction in SCC *** existence of chloride ion greatly lowered the passivation tendency and the film stability,while its concentration determined the dissolution rate of the steel *** p H value was responsible for the stable and tenacious passive films and the high repassivation *** was also inclined to lower the anodic dissolution rate at crack tips by retarding the cathodic oxygen reduction.

关键词： Pipeline steel Stress corrosion cracking (SCC) Passivation Chloride ion pH value

Study on deformation mechanism of Ti-2Al-2.5Zr alloy tube in the flattening test

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Journal of Materials Science & Technology 2021年第31期90卷 108-120页

作者： Shengkun Wang gang Jin Yuntao Wu xiao Liu gang Chen School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Nuclear and Radiation Safety Center MEE54#Beijing 100082China School of Chemical Engineering Sichuan UniversitySichuan 610065China Nuclear Power Institute of China ChengduSichuan 610015China

The flattening test,using one pair paralleled plates to flatten tube structure radially,is generally employed to examine the ductility of tube used in once through steam generator(OTSG).This study focuses on the stress condition and deformation mechanism analysis on the concentrated stress regions of Ti-2 Al-2.5 Zr alloy tube during the flattening ***,the finite element analysis was performed using the commercial software ABAQUS to determine the stress ***,the Electron BackScattered Diffraction(EBSD)was implemented to observe the microstructure evolution of Ti-2 Al-2.5 Zr ***,Schmid law was employed to analyze the activated deformation mechanism under condition of the complex *** was found that the condition of the complex stress in stress concentration regions,including tension and compression regions,can be simplified into two directional stresses *** grains whose c-axis is nearly towards TD and ND,the strain is mainly accommodated by prismatic slip,whereas in grains whose c-axis deviates about 45°from ND to TD mainly by basal ***{10-12}extensive twin and corresponding parent grain orientation mainly relied on the stress ***,the intergranular twin pairs connected at common grain boundaries(GBs)with high strain compatibility were found at low angle GBs,which were activated under a combination of macro stress and strain compatibility effect.

关键词： Ti-2Al-2.5Zr alloy tube Flattening test EBSD Stress condition Deformation mechanism Schmid factor Twin pairs Strain compatibility effect

Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

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Science China(Technological Sciences) 2024年第4期67卷 1124-1132页

作者： xiao Lu guo xiaoXiang SUN YuTong WANG gang LONG WeiMin LIAW Peter K. REN JingLi School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China SKL of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HEAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HEA was prepared using molecular dynamics simulation involving melt and quench *** HEA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-packed structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HEA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

Dependence of domain wall structures on repetition n in[Pt(0.5 nm)/Co(0.4 nm)]_n/NiO(1.1 nm)/[Co(0.4 nm)/Pt(0.5 nm)]_n multilayers

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 229-233页

作者： xiao-xia Li gang Han Experimental Center College of Science Yanshan University Qinhuangdao 066004 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The magnetic force microscopy and a sample vibrating magnetometer have been used to investigate the domain structure in two antiferromagnetically coupled Co/Pt *** the antiferromagnetic coupled[Pt（0.5 nm）/Co（0.4 nm）]n/NiO（1.1 nm）/[Co（0.4 nm）/Pt（0.5 nm）]n multilayers with perpendicular anisotropy,the antiferromagnetic interlayer coupling strength increases linearly with the repetition number n in Co/Pt *** demagnetized states,relatively shifted domain walls in the two Co/Pt multilayers are observed,with net ferromagnetic stripes formed between them for the repetition number n less than 5,and the stripe width decreases with the increase of *** occurrence of these features can be attributed to the competition between the interlayer coupling and magnetostatic energies.

关键词： perpendicular anisotropy antiferromagnets interlayer coupling domain walls magnetostatic energy

Microstructure,crystallography and nucleation mechanism of NANOBAIN steel

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1155-1163页

作者： Yao Huang Ai-min Zhao Jian-guo He xiao-pei Wang Zhi-gang Wang Liang Qi Metallurgy Engineering Research Institute University of Science and Technology Beijing School of Material Science and Engineering Jiangxi University of Science and Technology

The microstructure of bainite ferrite in NANOBAIN steel transformed at different temperatures was investigated by scanning electron microscopy, transmission electron microscopy, electron back-scattered diffraction, and vickers hardness tester in detail. It is found that the average width of bainitic ferrite （BF） plates can be refined to be thinner with the reduction of temperature （473-573 K）, and the bainitic ferrite plates can reach up to 20-74 nm at 473 K. Crystallographic analysis reveals that the bainitic ferrite laths are close to the Nishiyama-Wasserman orientation relationship with their parent austenite. Temperature shows a significant effect on the variant selection, and a decrease in temperature generally weakens the variant selection. Thermodynamic analyses indicates that the Lacher, Fowler and Guggenheim （LFG） model is more suitable than the Kaufman, Radcliffe and Cohen （KRC） model dealing with NANOBAIN steel at a low temperature range. The free energy change △G^γ→BF is about -1500 ***^-1 at 473 K, which indicates that nucleation in NANOBAIN steel is the shear mechanism. Finally, the formation of carbon poor regions is thermodynamically possible, and the existence of carbon poor regions can greatly increase the possibility of the shear mechanism.

关键词： nanostructured materials high strength steel bainitic transformations microstructure crystallography nucleation

Corrosion products of reverse crevice corrosion of copper

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International Journal of Minerals,Metallurgy and Materials 2011年第3期18卷 320-324页

作者： Lin Lu xiao-gang Li School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Open-circuit potential measurements and Raman spectroscopy were used to investigate the reverse crevice corrosion phenomenon and its corresponding corrosion products. With the aid of these techniques, the existence of reverse-crevice corrosion in copper was verified, i.e., while the surface of a crevice was corrosion free, the outside surface of the copper was attacked. The processes associated with this phe-nomenon were classified into three phases, and different compositions of the corrosion products were determined. Raman spectra showed that copper and Cu2O were found in the crevice, while CuO, Cu2O, and CuCl2 were the corrosion products on the bold surface. Based on these findings, a hypothesis relating to the three phases of reverse crevice corrosion has been proposed.

关键词： copper corrosion potential crevice corrosion corrosion products Raman spectroscopy

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川芎嗪治疗糖尿病慢性并发症

新乡医学院学报 1993年第3期10卷 187-190页

作者：翁孝刚郭永年王道直索新华张清贵新乡医学院第一附属医院内分泌科

研究目的探讨川芎嗪对糖尿病慢性并发症的治疗效果。研究背景微循环障碍是糖尿病慢性并发症发生发展的基础。改善微循环和血液流变学异常是治疗糖尿病慢性并发症的主要方法之一。研究方法将患者分为非川芎嗪治疗组(C组)和川芎嗪治疗组(... 详细信息

研究目的探讨川芎嗪对糖尿病慢性并发症的治疗效果。研究背景微循环障碍是糖尿病慢性并发症发生发展的基础。改善微循环和血液流变学异常是治疗糖尿病慢性并发症的主要方法之一。研究方法将患者分为非川芎嗪治疗组(C组)和川芎嗪治疗组(川组)。川组患者采用川芎嗪320～400mg/天加液中静滴,2周为1疗程,多数患者治疗1～2疗程。研究结果治疗多发性末梢神经病变92例,总有效率为88.0％,明显高于C组(29.0％,P<0.005);治疗视网膜病变49例,总有效率为81.6％,也明显高于C组(25.0％,P<0.005)。同时,川芎嗪可明显改善患者的血液流变学异常。结论大剂量川芎嗪静滴是治疗糖尿病慢性并发症的有效方法之一。

关键词：川芎嗪糖尿病视网膜病变

Cloning and Characterization of a Somatic Embryogenesis Receptor-Like Kinase Gene in Cotton (Gossypium hirsutum)

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Journal of Integrative Agriculture 2012年第6期11卷 898-909页

作者： SHI Ya-li ZHANG Rui WU xiao-ping MENG Zhi-gang guo San-dui Biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijing 100081P.R.China

A novel gene, GhSERK1, was identified in cotton. It encoded a protein belonging to the somatic embryogenesis receptor- like kinase （SERK） family. The genomic sequence of GhSERK1 was 6 920 bp in length, containing a predicted transcriptional start site （TSS）. Its full-length cDNA was 2 502 bp, encoding a protein of 627 amino acids. Sequence analysis of GhSERK1 revealed high levels of similarity to other reported SERKs, as well as a conserved intron/exon structure that was unique to members of the SERK family. Expression analysis showed that GhSERK1 mRNA was present in all organs of cotton plants and at different developmental stages, but its transcripts were most abundant in reproductive organs. Compared with that of the male-fertile line, the level of GhSERK1 mRNA was lower in the anther of the male-sterile cotton line, in which the pollen development was defected. Taken together, these findings illustrated that the GhSERK1 play a critical role during the anther formation, and may also have a broad role in other aspects of plant development.

关键词： cotton (Gossypium hirsutum) somatic embryogenesis receptor-like kinase (SERK) reproductive organs,anther development