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Weak KAM theory for two classes of almost periodic Hamiltonian systems

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Science China Mathematics 2025年

作者： xun Niu Kaizhi wang Yong Li School of Mathematics and Statistics Center for Mathematics and Interdisciplinary SciencesNortheast Normal University School of Mathematical Sciences Shanghai Frontier Science Center of Modern Analysis (CMA-Shanghai)Shanghai Jiao Tong University Institute of Mathematics Jilin University

The purpose of this paper is to investigate the dynamics of Bohr almost periodic and Levitan almost periodic Hamiltonian systems via the weak KAM theory. We obtain minimal measures and weak KAM solutions in both cases. The weak KAM solution is a weak solution to the Hamilton-Jacobi equation, which formally transforms the original Hamiltonian systems into an integrable one. Consequently, we get the existence of an invariant torus in the aforementioned weak sense.

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Qian-Zheng-San promotes regeneration after sciatic nerve crush injury in rats

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Neural Regeneration Research 2019年第4期14卷 683-691页

作者： zhi-Yong wang Li-Hua Qin Wei-guang Zhang Pei-xun Zhang bao-Guo Jiang Department of Anatomy and Histo-embryology School of Basic Medical Sciences Peking University Department of Trauma and Orthopedics Peking University People's Hospital

Qian-Zheng-San, a traditional Chinese prescription consisting of Typhonii Rhizoma, Bombyx Batryticatus, Scorpio, has been found to play an active therapeutic role in central nervous system diseases. However, it is unclear whether Qian-Zheng-San has therapeutic value for peripheral nerve injury. Therefore, we used Sprague-Dawley rats to investigate this. A sciatic nerve crush injury model was induced by clamping the right sciatic nerve. Subsequently, rats in the treatment group were administered 2 mL Qian-Zheng-San(1.75 g/mL) daily as systemic therapy for 1, 2, 4, or 8 weeks. Rats in the control group were not administered Qian-Zheng-San. Rats in sham group did not undergo surgery and systemic therapy. Footprint analysis was used to assess nerve motor function. Electrophysiological experiments were used to detect nerve conduction function. Immunofluorescence staining was used to assess axon counts and morphological analysis. Immunohistochemical staining was used to observe myelin regeneration of the sciatic nerve and the number of motoneurons in the anterior horn of the spinal cord. At 2 and 4 weeks postoperatively, the sciatic nerve function index, nerve conduction velocity, the number of distant regenerated axons and the axon diameter of the sciatic nerve increased in the Qian-Zheng-San treatment group compared with the control group. At 2 weeks postoperatively, nerve fiber diameter, myelin thickness, and the number of motor neurons in the lumbar spinal cord anterior horn increased in the Qian-Zheng-San treatment group compared with the control group. These results indicate that QianZheng-San has a positive effect on peripheral nerve regeneration.

关键词： nerve regeneration traditional Chinese medicine crush injury peripheral nerve regeneration nerve conduction velocity sciatic function index nerve injury nerve repair formula scorpion neural regeneration

Advances and applications in single-cell and spatial genomics

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Science China Life Sciences 2025年

作者： Jingjing wang Fang Ye Haoxi Chai Yujia Jiang Teng wang Xia Ran Qimin Xia Ziye Xu Yuting Fu Guodong Zhang hanyu Wu Guoji Guo Hongshan Guo Yijun Ruan Yongcheng wang dong Xing xun Xu Zemin Zhang Beijing Advanced Innovation Center for Genomics (ICG) Peking University guangdong Provincial Key Laboratory of Genome Read and Write BGI Research Bone Marrow Transplantation Center of the First Affiliated Hospital & Liangzhu Laboratory Zhejiang University School of Medicine Life Sciences Institute and The Second Affiliated Hospital Zhejiang University BGI Research Biomedical Pioneering Innovation Center (BIOPIC) and School of Life Sciences Peking University Academy for Advanced Interdisciplinary Studies Peking University Institute of Hematology Zhejiang University Department of Laboratory Medicine of The First Affiliated Hospital & Liangzhu Laboratory Zhejiang University School of Medicine Center for Stem Cell and Regenerative Medicine Zhejiang University School of Medicine Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine Dr.Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine

The applications of single-cell and spatial technologies in recent times have revolutionized the present understanding of cellular states and the cellular heterogeneity inherent in complex biological systems. These advancements offer unprecedented resolution in the examination of the functional genomics of individual cells and their spatial context within tissues. In this review, we have comprehensively discussed the historical development and recent progress in the field of single-cell and spatial genomics. We have reviewed the breakthroughs in single-cell multi-omics technologies, spatial genomics methods, and the computational strategies employed toward the analyses of singlecell atlas data. Furthermore, we have highlighted the advances made in constructing cellular atlases and their clinical applications,particularly in the context of disease. Finally, we have discussed the emerging trends, challenges, and opportunities in this rapidly evolving field.

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Creep prediction model for nickel-based single-crystal superalloys considering precipitation of TCP phase

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Rare Metals 2021年第10期40卷 2892-2904页

作者： Xiao-Yan wang Jia-Jia wang cheng-Jiang Zhang wen-Wei Tong Bo Jiang guang-Xian Lu zhi-xun wen Tao Feng Department of Engineering Mechanics Northwestern Polytechnical UniversityXi’an 710072China School of Science Xi’an Shiyou UniversityXi’an 710065China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

The microstructure of nickel-based single-crystal(SC) superalloys has a pivotal influence on their creep properties. The addition of the Re element not only enhances the long-term creep properties of nickel-based SC superalloys, but also results in the formation of a topologically close-packed(TCP) phase which is a harmful and brittle hard phase. Here, high-temperature creep interruption tests of a nickel-based SC superalloy that contains4.8 wt% Re were performed under various temperatures and stress conditions, and the evolution of microstructure during creep was observed by scanning electron microscopy(SEM). The volume fraction of the TCP phase was also extracted to explore the mechanism that controls the impacts of the TCP phase on the creep *** to the microstructure evolution mechanism, the influence of the TCP phase was attributed to the initial damage and critical shear stress of the material. A creep performance prediction model for nickel-based SC superalloys considering the precipitation of the TCP phase that is based on the crystal plasticity theory and a modified creep damage model was established. The simulation curves fit well with the experimental results and the errors between prediction creep life with test results are within 5%.

关键词： TCP phase Nickel-based single-crystal superalloys Microstructure evolution Creep performance prediction Crystal plasticity theory

Effect of indium addition on the microstructural formation and soldered interfaces of Sn-2.5Bi-1Zn-0.3Ag lead-free solder

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International Journal of Minerals,Metallurgy and Materials 2012年第11期19卷 1029-1035页

作者： ming-jie dong zhi-ming Gao Yong-chang Liu xun wang Li-ming Yu School of Materials Science&Engineering Tianjin Key Laboratory of Advanced Jointing TechnologyTianjin UniversityTianjin 300072China

The microstructural formation and properties of Sn-2.5Bi-xln-lZn-0.3Ag （in wt%） alloys and the evolution of soldered interfaces on a Cu substrate were investigated. Apart from the relatively low melting point （about 195C）, which is close to that of conventional eutectic Sn-Pb solder, the investigated solder presents superior wettability, solderability, and ductility. The refined equiaxial grains enhance the me- chanical properties, and the embedded bulk intermetallic compounds （IMCs）（Cu6Sn5 and CusZns） and granular Bi particles improve the joint reliability. The addition of In reduces the solubility of Zn in the 13-Sn matrix and strongly influences the separation and growth behaviors of the IMCs. The soldered interface of Sn-2.5Bi-xln-lZn-0.3Ag/Cu consists of Cu-Zn and Cu-Sn IMC layers.

关键词： soldering alloys indium microstrucmre interfaces melting point intermetallics

Self-templated nitrogen-doped mesoporous carbon decorated with double transition-metal active sites for enhanced oxygen electrode catalysis

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Rare Metals 2020年第7期39卷 824-833页

作者： Meng-Fei Qiao Ying wang Lei Li guang-zhi Hu Guo-An Zou Xamxikamar Mamat Ye-Min dong xun Hu Key Laboratory of Chemistry of Plant Resources in Arid Regions Xinjiang Technical Institute of Physics and ChemistryChinese Academy of ScienceUrumqi 830011China College of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing 314001China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China School of Material Science and Engineering University of JinanJinan 250022China

The development of high-performance,low-cost bifunctional catalysts with long-term stability for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is one of the most critical challenges for the large-scale application of metal-air ***,we report an advanced nitrogen-doped mesoporous carbon(NMC)composite(NiCo2O4/CoNx-NMC)formed from a mixture of Co-and Ni-hydroxide-infiltrated phenolic resin and melamine *** composite exhibits superior electrocatalytic activity,stability,and selectivity for the ORR and *** activity parameter(DE),which is an indicator of the overall catalytic activity of bifunctional catalysts,was 0.76 V for NiCo2O4/***,catalyst outperforms the majority of previously reported non-precious metal-based bifunctional *** remarkable ultra-high catalytic performance of NiCo2O4/CoNx-NMC for the ORR and OER can be attributed to the presence of different active sites of the CoNx structure and the formation of NiCo2O4 with the spinel structure,which was obtained by a stepwise pyrolysis *** synthesis strategy opens a new avenue for the rational design of highly active bifunctional electrocatalysts.

关键词： Bifunctional catalysis Oxygen reduction reaction Oxygen evolution reaction Pyrolysis strategy Double active sites

Strip flatness prediction of cold rolling based on ensemble methods

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Journal of Iron and Steel Research International 2024年第1期31卷 237-251页

作者： Wu-quan Yang zhi-ting Zhao Liang-yu Zhu xun-yang Gao Li wang School of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang110142LiaoningChina

Aiming at the problem of insufficient prediction accuracy of strip flatness at the outlet of cold tandem rolling,the prediction performance of strip flatness based on different ensemble methods was studied and a high-precision prediction ensemble model of strip flatness at the outlet was ***,based on linear regression(LR),K nearest neighbors(KNN),support vector regression,regression trees(RT),and backpropagation neural network(BPN),bagging,boosting,and stacking ensemble methods were used for ensemble ***,three existing ensemble models,i.e.,random forest,extreme random tree(ET)and extreme gradient boosting,were used to conduct experiments and compare the *** research shows that bagging,boosting,and stacking three ensemble methods have the most significant improvement in the prediction accuracy of the regression trees model,which is increased by 5.28%,6.51%,and 5.32%,*** the same time,the stacking ensemble method improves both the simple model and the complex model,and the improvement effect on the simple base model is the greatest,which is 4.69%higher than that of the base model *** all of the ensemble models,the stacking ensemble model of level-1(ET,AdaBoost-RT,LR,BPN)paired with level-2(LR)was discovered to be the best model(EALB-LR)and can be further studied for industrial applications.

关键词： Tandem cold rolling Flatness prediction Machine learning Ensemble method

The mitochondrial genome of the plant bug Apolygus lucorum （Hemiptera： Miridae）＂ Presently known as the smallest in Heteroptera

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Insect Science 2014年第2期21卷 159-173页

作者： Pei wang Hu Li Ying wang Jian-Hua Zhang xun Dai Jian Chang bao-wen Hu Wan-zhi Cai Department of Entomology China Agricultural University Beijing Research Center of Hongta Group Yuxi Yunnan China

The complete mitochondrial （mt） genome of the plant bug, Apolygus lucorum, an important cotton pest, has been sequenced and annotated in this study. The entire circular genome is 14 768 bp in size and represents the smallest in presently known heteropteran mt genomes. The mt genome is encoding for two ribosomal RNA （rRNA） genes, 22 transfer RNA （tRNA） genes, 13 protein coding genes and a control region, and the order, content, codon usage and base organization show similarity to a great extent to the hypothetical ancestral model. All protein coding genes use standard initiation codons ATN. Conventional stop codons TAA and TAG have been assigned to the most protein coding genes; however, COIII, ND4 and ND5 genes show incomplete terminator signal （T）. All tRNA genes possess the typical clover leaf structure, but the dihydrouridine arm of tRNAser（A6N） only forms a simple loop. Secondary structure models of rRNA genes are generally in accordance with the former models, although some differences exist in certain parts. Three intergenic spacers have never been found in sequenced mt genomes of Heteroptera. The phylogenetic study based on protein coding genes is largely congruent with previous phylogenetic work. Both Bayesian inference and maximum likelihood analyses highly support the sister relationship ofA. lucorum and Lygus lineolaris, and Miridae presents a sister position to Anthocoridae.

关键词： Apolygus lucorum Cimicomorpha Miridae mitochondrial genome phylo-genetic relationship secondary structure

Synthesis and Kinetics of a Novel Mimic with Glutathione Peroxidase Activity—Tellurium-containing Hyaluronic Acid (TeHA)

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Chinese Chemical Letters 2006年第7期17卷 969-972页

作者： zhi Bo chen Bo xun ZhanG Zhong Xiu HUANG Qing Lin PENG Jia chen Yu wang Jian Guo ZhanG guang zhi JIANG wen Shu LI Lan Ying LIU College of Life Science Jilin University Changchun 130023 State Key Laboratory of Electroanalytical Chemistry Chinese Academy of SciencesChangchun Institute of Applied Chemistry Changchun 130022

A novel mimic was synthesized by modifying hyaluronic acid （HA） with tellurium, whose function is similar to that of glutathione peroxidase （GPX）. The structure of TeHA was characterized by means of IR and NMR, the target-Te was located at -CH2OH of the N-acetyl-D- glucosamine of HA. The H202 reducing activity of TeHA, by glutathione （GSH）, was 163.6 U/μmol according to Wilson＇s method. In contrast to other mimics, TeHA displayed the highest activity. Moreover, TeHA accepted many hydroperoxides as its substrates, such as H2O2, cumenyl hydroperoxide （CuOOH） and tert-butyl hydroperoxide （t-BuOOH）, and CuOOH was the optimal substrate of TeHA. A ping-pong mechanism was observed in the steady-state kinetic studies of the reactions catalyzed by TeHA.

关键词： Hyaluronic acid tellurium glutathione peroxidase synthesis kinetics.