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Homological Epimorphisms, Compactly Generated t-Structures and Gorenstein-Projective Modules

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Chinese Annals of Mathematics,Series B 2018年第1期39卷 47-58页

作者： Nan GAO xiaojing xu Department of Mathematics Shanghai University Shanghai 200444 China

The aim of this paper is *** a recollement(T′,T,T′′,i*,i_*,i~!,j!,j*,j*),where T′,T,T′′are triangulated categories with small coproducts and T is compactly ***,the authors show that the BBD-induction of compactly generated t-structures is compactly generated when i*preserves compact *** a consequence,given a ladder(T′,T,T′′,T,T′) of height 2,then the certain BBD-induction of compactly generated t-structures is compactly *** authors apply them to the recollements induced by homological ring *** is the first part of their *** a recollement(D(B-Mod),D(A-Mod),D(C-Mod),i*,i_*,i~!,j!,j*,j_*) induced by a homological ring epimorphism,the last aim of this work is to show that if A is Gorenstein,AB has finite projective dimension and j! restricts to D^b(C-mod),then this recollement induces an unbounded ladder(B-Gproj,A-Gproj,C-Gproj) of stable categories of finitely generated Gorenstein-projective *** examples are described.

关键词： Compactly generated t-structure Recollement BBD-induction BPP-induction Homological ring epimorphism Gorensteinprojective module

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Journal of Systems Engineering and Electronics 2008年第5期19卷 945-951页

作者： Li Jian xu xiaojing Shi Kaiquan School of Mathematics and System Science Shandong Univ. Jinan 250100 P. R. China School of Computer Science & Technology Shandong Jianzhu Univ. Jinan 250101 P. R. China

Based on rough similarity degree of rough sets and close degree of fuzzy sets, the definitions of rough similarity degree and rough close degree of rough fuzzy sets are given, which can be used to measure the similar degree between two rough fuzzy sets. The properties and theorems are listed. Using the two new measures, the method of clustering in the rough fuzzy system can be obtained. After clustering, the new fuzzy sample can be recognized by the principle of maximal similarity degree.

关键词： rough fuzzy set rough similarity degree rough close degree clustering recognition of rough pattern,maximal similarity degree principle.

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Journal of Systems Engineering and Electronics 2008年第2期19卷 311-315页

作者： xu xiaojing Li Jian Shi Kaiquan School of Computer Science & Technology Shandong Jianzhu Univ. Jinan 250101 P. R. China School of Mathematics and System Science Shandong Univ. Jinan 250100 P. R. China

The definition of rough similarity degree is given based on the axiomatic similarity degree, and the properties of rough similarity degree are listed. Using the properties of rough similarity degree, the method of clustering in rough systems can be obtained. After clustering, a new sample can be recognized by the principle of maximal rough similarity degree.

关键词： rough similarity degree clustering recognition of rough pattern maximal similarity degree principle.

Hot Corrosion Resistance of TB8 Titanium Alloy after ECAP and Heat Treatment

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Journal of Wuhan University of Technology(Materials Science) 2023年第6期38卷 1440-1448页

作者： LI Shuaidi xu xiaojing BAI Xiang CAO Bin Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang 212013China

The metastableβtitanium alloy TB8(Ti-12.76Mo-2.13Nb-2.73A1-0.16Si)was used as the original material,and the secondary processing method combining equal channel angular pressing(ECAP)and heat treatment was *** the help of optical microscope(OM),scanning electron microscope(SEM)and X-ray diffractometer(XRD),the corrosion behavior of TB8 titanium alloy after different secondary processing(800℃/850℃solid solution-520℃aging,ECAP-800℃/850℃solid solution-520℃aging,and800℃/850℃solid solution-ECAP-520℃aging)was *** experimental results show that the hot corrosion products of the six samples are similar,mainly Na_(2)Si_(2)O_(5),MoS_(2),TiCl_(2),Ti(SO_(4))_(2),and *** to the grains of the TB8 titanium alloy treated by 850℃solid solution-ECAP-520℃aging are obviously refined,the surface structure is the most smooth and dense,forming a continuous Al2O3protective film,and the surface defects are the least after *** corrosion layer thickness is the lowest(102.3μm),only 36.5%-81.4%of that of other secondary processing titanium *** addition,the corrosion kinetics curves of the six materials all follow parabolic laws,and the minimum corrosion weight gain of the samples after 850℃solutionECAP-520℃aging treatment is 0.7507 mg·mm^(-2),showing better hot corrosion resistance.

关键词： TB8 ECAP heat treatment hot corrosion resistance

Numerical analysis of thermal-hydraulic behavior of supercritical water in vertical upward/downward flow channels

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Nuclear Science and Techniques 2008年第3期19卷 178-186页

作者： GU Hanyang YU Yiqi CHENG xu LIU xiaojing School of Nuclear Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

Investigations on the thermal-hydraulic behavior in the SCWR fuel assembly have obtained a significant attention in the international SCWR community. However, there is still a lack of understanding of the heat transfer behavior of supercritical fluids. In this paper, the numerical analysis is carried out to study the thermal-hydraulic behaviour in vertical sub-channels cooled by supercritical water. Remarkable differences in characteristics of secondary flow are found, especially in square lattice, between the upward flow and downward flow. The turbulence mixing across sub-channel gap for downward flow is much stronger than that for upward flow in wide lattice when the bulk temperature is lower than pseudo-critical point temperature. For downward flow, heat transfer deterioration phenomenon is suppressed with respect to the case of upward flow at the same conditions.

关键词：传热理论热转换数字分析水力行为

Attractor and Stability of Delayed Boolean Networks with State Constraints 36

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Attractor and Stability of Delayed Boolean Networks with Sta...

Pers onal In come Tax Reform in China in 2018 and Its Impact on Income Distribution

第36届中国控制会议

作者： ZHENG Yating LI Haitao xu xiaojing School of Mathematics and Statistics Shandong Normal University

ISBN: (纸本)9781538629185

This paper investigates the attractor and stability of delayed Boolean networks（DBNs） with/without state constraints by using the semi-tensor product of matrices. Firstly, the dynamics of DBNs with/without state constraints is converted into an equivalent algebraic form via the semi-tensor product of matrices. Secondly, based on the algebraic form, a new formula is proposed for the calculation of number of attractors for DBNs with state constraints. Thirdly, a necessary and sufficient condition is presented for the stability of DBNs with state constraints. Finally, an example is worked out to show the application of the obtained new results.

关键词： Delayed Boolean Network Attractor Stability State Constraint Semi-Tensor Product of Matrices

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China & World Economy 2019年第3期27卷 25-48页

作者： Peng Zhan Shi Li xiaojing xu School of Economics Nanjing University of Finance & Economics China Institute for Income Distribution Beijing Normal University China

In the context of personal income tax(PIT)reform in China in 2018,this paper examines some of the major issues of concern regarding the reform and income *** the China Personal Income Tax Micro-simulation model,the paper compares the differences between the 2011 and 2018 PIT systems,and finds that residents relying on different income sources may face a large degree of real tax rate *** the tax system is altered to PIT 2018,the coverage of PIT for wage earners will decrease from 46.9 to 23.4 percent,the income redistributive effect will drop from 1.95 to 1.22 percent and the PITs role in fiscal revenue will also be negatively ***,if individual income continues to grow,the share of PIT in fiscal revenue is expected to return to the 2018 level in 2022,but its income redistribution function is difficult to recover in the short *** paper finds that the effect of PIT on income distribution depends on the tax *** transition to an"entirely comprehensive"tax system when conditions are appropriate will achieve better income redistribution results at a lower average tax rate.

关键词： micro-simulation personal income tax reform residential income distribution

On the Distance Spectra of Several Double Neighbourhood Corona Graphs

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Journal of Mathematical Research with Applications 2019年第3期39卷 233-248页

作者： xiaojing xu Zhiping WANG Jiaxue xu Department of Mathematics Dalian Maritime University

Let G be a connected graph of order n and D（G） be its distance matrix. The distance eigenvalues of G are the eigenvalues of its distance matrix. Its distance eigenvalues and their multiplicities constitute the distance spectrum of G. In this article, we give a complete description of the eigenvalues and the corresponding eigenvectors of a block matrix DNC. Further, we give a complete description of the eigenvalues and the corresponding eigenvectors of distance matrix of double neighbourhood corona graphs G（S）· {G1, G2}, G（Q）· {G1, G2}, G（R）· {G1, G2},G（T）· {G1, G2}, where G is a complete graph and G1, G2are regular graphs.

关键词： corona distance spectrum double neighbourhood corona graph block matrix

Superplasticity of a SiCw/Zn-22Al Composites

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Journal of Materials Science & Technology 2004年第2期20卷 172-174页

作者： xiaojing xu, Wei WANG and Lan CAISchool of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China School of Mechanical Engineering Jiangsu University Zhenjiang 212013 China

In this paper, the superplastic characteristics of a 15 SiC(vol. pct) whisker reinforced Zn-22AI alloy composites, fabricated by low pressure infiltration and solute treatment after extrusion with the extrusion rate of 10:1, was investigated. The result showed that the composite exhibited a tensile elongation of 150% and a strain rate sensitivity value of about 0.33 at the initial strain rate of 6.67×10-2 s-1 and at 658 K where an appropriate amount of liquid phase was presented in the composite.

关键词： Superplasticity SiCw/Zn-22Al matrix composite Liquid phase