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A Covering Lemma on the Unit Sphere and Application to the Fourier-Laplace Convergence

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Acta Mathematica Sinica,English Series 2007年第7期23卷 1327-1332页

作者： rong HUANG Kun Yang wang Department of Mathematics Tianjin Normal University School of Mathematical Sciences Beijing Normal University

A covering lemma on the unit sphere is established and then is applied to establish an almost everywhere convergence test of Marcinkiewicz type for the Fourier-Laplace series on the unit sphere which can be stated as follows：Theorem Suppose f ∈ L（En-1）, n≥ 3. If f satisfies the condition1/θ^n-1∫D（x,θ）｜f（y）-f（x）｜dy=O（1/｜logθ｜）,as θ→0＋,at every point x in a set E of positive measure in Σn-1, then the Cesàro means of critical order ,n-2/2 of the Fourier-Laplace series of f converge to f at almost every point x in E.

关键词： sphere covering lemma Fourier-Laplace series a.e. convergence

Mechanical and Transformation Behaviors of a C-Mn-Si-Al-Cr TRIP Steel under Stress

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Journal of Materials Science & Technology 2006年第5期22卷 625-628页

作者： Xiaodong wang Baoxu HUANG Yonghua rong Li wang School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China Baosteel Research and Development Technology Center Shanghai 201900 China

Transformation induced plasticity （TRIP） steels combine high strength and excellent ductility, making them suited for application in crash-relevant parts in the automotive industry. However, the high Si contents in the conventional TRIP steel will generate surface defects on the hot rolled strip, which is difficult to process in continuous galvanizing lines. In order to solve the above problem the TRIP steel with the addition of Al replacing majority of Si was designed. In the present paper, the volume fraction of various phases in a C-Mn-Si-Al-Cr TRIP steel was determined by metallographic examination and X-ray diffraction analysis, and the multi-phase microstructures were characterized using an atomic force microscope based on their height difference. Tensile tests were performed at different temperatures ranging from -40℃ to 90℃. The results show that transition temperature Ms^σ in the present TRIP steel cannot be determined due to its lower volume fraction of retained austenite, different from the conventional TRIP steel. While the yield stress and tensile strength at different temperatures are higher than those of the conventional TRIP steel, which is attributed to the addition of Cr. In order to evaluate the effect of martensitic transformation on the total elongation, the sample without retained austenite obtained by quenching in liquid nitrogen was carried out under tensile test. The results indicate that the elongation of the original sample containing 9% retained austenite is about 20% higher than that of the sample quenched in liquid nitrogen, which demonstrates that the retained austenite plays an important role in improving the elongation of the TRIP steel.

关键词： TRIP steel Mechanical properties Retained austenite Martensitic transformation

Interface Migration between Martensite and Austenite during Quenching and Partitioning (Q&P) Process

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Journal of Materials Science & Technology 2006年第6期22卷 751-754页

作者： Ning ZHONG Xiaodong wang Yonghua rong Li wang School of Materials Science and Engineering Shanghai Jiao Tiong University Shanghai 200030 China Baosteel Research and Development Technology Center Shanghai 201900 China

An Fe-0.2C-1.5Si-1.67Mn steel was subjected to quenching and partitioning （Q＆P） process, and the interface migration between martensite and austenite at an elevated partitioning temperature was observed. The interface migration is excluded in constrained paraequilibrium （CPE） model. Based on ＂endpoint＂ predicted by CPE model the thermodynamic condition of interface migration is analyzed, that is, the difference in the chemical potential of iron in both ferrite （martenisite） and austenite produces the driving force of the iron atoms to migrate from one phase to the other phase. In addition, the interface migration can change the austenite fraction; as a result, the austenite fraction at partitioning temperature may be higher than that at quenching temperature through the interface migration, but this phenomenon cannot be explained by CPE model.

关键词： Quenching and partitioning (Q&P) Constrained paraequilibrium (CPE) Martensite Austenite Interface migration

Regular Balanced Cayley Maps for Cyclic,Dihedral and Generalized Quaternion Groups

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Acta Mathematica Sinica,English Series 2005年第4期21卷 773-778页

作者： Yan wang rong Quan FENG Department of Mathematics Yan Tai University Yan Tai 264005. P. R. China LMAM School of Mathematical Sciences Peking University Beijing 100871 P. R. China

A Cayley map is a Cayley graph embedded in an orientable surface such that. the local rotations at every vertex are identical. In this paper, balanced regular Cayley maps for cyclic groups, dihedral groups, and genera... 详细信息

关键词： Map Cayley map Regular Balanced

Synthesis of novel benzo[b]pyrimido[4',5':5,4]thieno[2,3-e][1,6]naphthyridine-8-ones via Pictet–Spengler cyclization

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Chinese Chemical Letters 2016年第2期27卷 261-264页

作者： dao-Lin wang Xiao-Ce Shi Yong-Yang wang Jian Ma College of Chemistry and Chemical Engineering Liaoning Key Laboratory of Synthesis and Application of Functional Compound Bohai University

An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′：5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-（3-aminopyrimido[4,5-d]thieno-2-yl）quinoline-2-ones, which could be obtained from Thorpe-Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF3·OEt2 gives pyrimidothieno[1,6]naphthyridines in good yields.

关键词： 4-Bromomethylquinoline-2-one 5-Cyano-6-thioxopyrimidine Pyrimido[4′,5′:5,4]thieno[2-3e]naphthyridine Thorpe-Ziegler reaction Pictet-Spengler reaction

Small modifications of endo-functionalized cavities lead to large changes in molecular interaction in water

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Science China Chemistry 2025年第01期 369-376页

作者： Song-Meng wang Hao Nian Yan-Fang wang Li-Shuo Zheng Yu-Tao Zheng Yi-Wei Dong Liping Huang Xiaoping wang Wei Jiang Liu-Pan Yang Department of Chemistry Southern University of Science and Technology School of Chemistry and Pharmaceutical Sciences State Key Laboratory for Chemistry and Molecular Engineering of Medicinal ResourcesGuangxi Normal University School of Pharmaceutical Science Hengyang Medical School University of South China

Studying molecular recognition in aqueous environments is crucial for understanding biological processes. Herein, we present a series of N-doped endo-functionalized anthracene-based cavities by introducing inward-directed pyridine units. The subtle modifications can significantly affect the binding properties of these receptors, which is similar to the mutations in biological systems. Combining theoretical calculations and molecular recognition experiments demonstrated that these “mutations” have an impact on the hydrophobicity and charge distribution of the hosts, consequently significantly influencing molecular *** is crucial for understanding the intricate mechanisms of molecular-level interactions in biological receptors.

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Nogo-A aggravates oxidative damage in oligodendrocytes

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Neural Regeneration Research 2021年第1期16卷 179-185页

作者： Yang-Yang wang Na Han dao-Jun Hong Jun Zhang Department of Neurology Peking University People’s HospitalBeijingChina Department of Neurology The First Affiliated Hospital of Nanchang UniversityNanchangJiangxi ProvinceChina

Nogo-A is considered one of the most important inhibitors of myelin-associated axonal regeneration in the central nervous *** is mainly expressed by *** previous studies have found regulatory roles for Nogo-A in neurite outgrowth inhibition,neuronal homeostasis,precursor migration,plasticity,and neurodegeneration,its functions in the process of oxidative injury are largely *** this study,oligodendrocytes were extracted from the cerebral cortex of newborn Sprague-Dawley *** used hydrogen peroxide(H2O2)to induce an in vitro oligodendrocyte oxidative damage model and found that endogenously expressed Nogo-A is significantly upregulated in *** recombinant virus Ad-ZsGreen-rat Nogo-A infection of oligodendrocytes,Nogo-A expression was increased,and the infected oligodendrocytes were more susceptible to acute oxidative insults and exhibited a markedly elevated rate of cell ***,knockdown of Nogo-A expression in oligodendrocytes by Ad-ZsGreen-shRNA-Nogo-A almost completely protected against oxidative stress induced by exogenous *** with a Nogo-66 antibody,a LINGO1 blocker,or Y27632,an inhibitor in the Nogo-66-NgR/p75/LINGO-1-RhoA-ROCK pathway,did not affect the death of ***-ZsGreen-shRNA-Nogo-A also increased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and inhibited BCL2 expression in *** conclusion,Nogo-A aggravated reactive oxygen species damage in oligodendrocytes,and phosphorylated extracellular signal-regulated kinase 1/2 and BCL2 might be involved in this *** study was approved by the Ethics Committee of Peking University People’s Hospital,China(approval No.2018PHC081)on December 18,2018.

关键词： BCL2 H2O2 LINGO1 NgR Nogo-A oligodendrocytes phosphorylated extracellular signal-regulated kinase 1/2 reactive oxygen species

An efficient method for the synthesis of thieno[3',2':2,3]pyrido-[4,5-d]-thiazolo[3,2-a]pyrimidinones

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Chinese Chemical Letters 2017年第3期28卷 579-582页

作者： dao-Lin wang Dong wang Jin-Juan Xing Jian-Hua Qian College of Chemistry and Chemical Engineering Liaoning Key Laboratory of Synthesis and Application of Functional Compound Bahai University Jinzhou 121003 China

An efficient method for the preparation of thieno[3＇,2＇：2,3]pyrido[4,5-d]thiazolo[3,2-a] pyrimidin-5-ones 5 is described. The key intermediate, 7-（3-amino-4-cyano-5-phenyl aminothieno-2-yl）-5H-thiazolo-[80_TD$IF]3,2-a]pyrimidin-5-one（3）, was synthesized from 7-chloromethyl-5H-thiazolo[3,2-a]pyrimidin-5-one（1）with potassium-（2,2-dicyano-1-phenylaminoethen-1-yl）thiolate（2） by Thorpe–Ziegler *** reaction of the intermediate amine with aromatic aldehydes via Pictet–Spengler reaction provided thieno-pyridine fused thiazolo[3,2-a]pyrimidines under p-Ts OH as catalyst in good yields.

关键词： Thiazolo[3 2-a]pyrimidinone Thienopyridothiazolo[3 2-a]pyrimidinone Thorpe–Ziegler isomerization Pictet–Spengler reaction

An efficient synthesis of novel benzo[b]pyrido[3',2':4,5]thieno[2,3-e][1,6]naphthy-ridine-8-ones

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Chinese Chemical Letters 2015年第9期26卷 1109-1112页

作者： dao-Lin wang Yong-Yang wang Xiao-Ce Shi Jian Ma College of Chemistry and Chemical Engineering Liaoning Key Laboratory of Synthesis and Application of Functional Compound Bohai University

An efficient method for the synthesis of novel benzo[b]pyrido[3＇,2＇：4,5]thieno[2,3-e][l,6]naphthyridine-8-one derivatives has been developed using a Pictet-Spengler reaction between 4-（3-aminothieno[2,3-b]pyridin-2-yl）quinoline-2-ones,which could be obtained from the alkylation of4-bromomethylquinoline-2-ones with 3-cyanopyridine-2-thione followed by a Thorpe-Ziegler isomerization,and aromatic aldehydes under p-TsOH as catalysis in good yields.

关键词： 4-Bromomethylquinoline-2-one 3-Cyanopyridine-2-thione Benzo[b]pyrido[3' 2':4 5 ]thieno[23-e][1 6] naphthyridine-8-one Thorpe-Ziegler reaction Pictet-Spengler reaction