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Journal of Materials Science & Technology 2019年第6期35卷 1099-1107页

作者： X.Y. Jiao J. Wang C.F. Liu z.p. guo G.D. Tong S.L. Ma Y. Bi Y.F. zhang S.M. Xiong School of Materials Science and Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Automobile Safety and Energy Tsinghua University Beijing China China FAW Foundry Co. Ltd. Changchun 130011. China

The fracture behavior of high-pressure die-cast hypereutectic(HpDC) Al-Si alloys was investigated using a high-resolution laboratory CT and synchrotron X-ray tomography with a particular focus on the influence of HpDC microstructure. Results showed that microstructure of the alloy was mainly comprised of primary silicon particles(pSps), Al dendrites, Cu-rich phases and pores. Most of the coarse pSps, Cu-rich phases and pores were located in the center of the specimen. The rapid solidification of HpDC led to a heterogeneous microstructural feature. Elemental Cu was enriched in the frontiers of solid-liquid interface, causing the formation of large size dendritic arms. The pores were formed in the interdendrites which endured high stress intensity under high applied stress. Microcracks were originated from pores and further connected Cu-rich phases causing intergranular fracture. pSps worked as obstacles causing piling-up dislocations in the phase interface. In the regions where large size of pSps enriched in, pSps ruptured rather than debonded from matrix, indicating transgranular fractures of pSps. Microcracks originated around pores and pSps tended to converge on the main cracks to decrease the energy required for crack propagation.

关键词： Hypereutectic Al-Si alloy primary silicon particles porosity Fracture morphology High pressure die casting

The linear self-attracting diffusion driven by the weighted-fractional Brownian motion II: The parameter estimation

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Science China Mathematics 2025年

作者： Litan Yan Rui guo Wenyi pei Department of Statistics College of Science Donghua University School of Statistics and Mathematics Zhejiang Gongshang University

Let Ba,bbe a weighted-fractional Brownian motion with Hurst indexes a and b such that a>-1and 0≤b<1∧（1+a）.In this paper,we consider the linear self-attracting diffusion ■ interacting diffusion (see Cranston and L...

Let Ba,bbe a weighted-fractional Brownian motion with Hurst indexes a and b such that a>-1and 0≤bpaper,we consider the linear self-attracting diffusion ■ interacting diffusion (see Cranston and Le Jan （1995）).Under the continuous observation,we study asymptotic ■ converges in distribution to the sum of the chi-square random variable with 1 degree of freedom and the random variable z1a,b.

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Low‑Temperature Oxidation Induced phase Evolution with Gradient Magnetic Heterointerfaces for Superior Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第1期17卷 191-204页

作者： zizhuang He Lingzi Shi Ran Sun Lianfei Ding Mukun He Jiaming Li Hua guo Tiande Gao panbo Liu School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710129People’s Republic of China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase ***,accordion-shaped Co/Co_(3)O_(4)@N-doped carbon nanosheets(Co/Co_(3)O_(4)@NC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation *** results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial ***,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic ***,the synthesized Co/Co_(3)O_(4)@NC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon *** design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption.

关键词： Magnetic heterointerfaces phase evolution Interfacial polarization Magnetic coupling Electromagnetic wave absorption

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang Yuning Li Yakun Gu Wei Ma Yuying Guan Mengyuan guo Qianqian Shao Xunming Ji Jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

Mesoporous Carbon-Tin Nanocomposites as Anode Materials for Li-ion Battery

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Journal of Materials Science & Technology 2008年第4期24卷 657-660页

作者： z. W.zhao z.p.guo p. Yao H.K.Liu Institute for Superconducting and Electronic Materials University of Wollongong NSW 2522 Australia ARC Centre of Excellence for Electromaterials Science University of Wollongong NSW 2522 Australia Centre for Analysis and Measurement Tianjin University Tianjin 300072 China

A new mesoporous carbon-tin （MC-Sn） nanocomposite has been successfully prepared via a two-step method. From the transmission electron microscopy （TEM） observations, the tin nanoparticles were decorated on the as-prepared mesoporous carbons. The mesoprous structure of the carbon can effectively buffer the volume changes during the Li-Sn alloying and de-alloying cycles. The as-prepared MC/Sn nanocomposite electrodes exhibited extremely good cycling stability, with the specific capacity of Sn in the composite electrode calculated to be 959.7 mAh-g-1, which amounts to an impressive 90.9% of the theoretical value （990 mAh-g-1）. The reversible capacity after 200 cycles is 96.1% of the first cycle reversible capacity, i.e., the capacity fade rate is only 0.0195% per cycle, which is even better than that of commercial graphite-based anodes.

关键词： Mesoporous Carbon Tin Nanocomposites Lithium ion battery

On the topological number in Kelvin's circulation of inviscid fluids

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Communications in Theoretical physics 2024年第12期76卷 176-180页

作者： z B guo State Key Laboratory of Nuclear physics and Technology School of Physics Peking University

Kelvin's circulation,as a loop integral of the velocity field,is first shown to be equal to Γc=2πΔnΓ1+constant in an inviscid fluid,with Γ1a unit *** integer Δn is interpreted as the number of net 27r-rotations of the velocity vector in one cyclicality along the circulation loop and hence it is a topological *** from the linkage number in the helicity invariant,which only exists in 3D space,the topological number in the circulation invariant is independent of the spatial dimension.A further study reveals that this new topological phase 2πΔn is rooted at the gauge invariance of the circulation and it is a counterpart of the Berry's phase in the quantum system.

关键词： Berry's phase fluids Kelvin’s circulation topological number

Effects of Nitridation on properties of SiC Fiber and Interface of Ti Matrix Composite

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Journal of Materials Science & Technology 2002年第6期18卷 563-565页

作者： NanlinSHI z.X.guo 等 InstituteofMetalResearch ChineseAcademyofSciencesShenyang110016China DepartmentofMaterials QueenMaryUniversityofLondonMileEndRoadLondonE14NSUK

prenitridation of the TiBx coating surface of the Sigma SM1240 SiC fiber can form more stable compounds at the surface and obstruct the release of boron atoms into the Ti-based alloy matrix. The effect of nitridation on the tensile strength of the fiber was investigated in this work. Nitridation could degrade the tensile strength of the SiC fiber if the treating temperature and time are not optimized. The chemical reaction between the W core and SiC and the modification of fiber microstructure during the nitridation are responsible for the degradation in strength. The strength can be maintained by further optimization of the treating temperature and time. Therefore, stabilizing the surface of TiBx coating and hence the interface of the SiCf/Ti composite by the nitridation of the SiC fiber is a feasible technique for practical applications.

关键词： SiC fiber Surface coating Nitridation Tensile strength Interface

pRECIpITATION AND GROWTH OF pEROVSKITE pHASE IN TITANIUM BEARING BLAST FURNACE SLAG

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 9-14页

作者： z.z. guo T.p. Lou L. zhang L.N. zhang z.T. Sui School of Materials and Metallurgy Northeastern University Shenyang 110006 Ghina

The effects of transformation of slag composition and additive agents on the morphology, the precipitation behavior, the crystal growth, and the volume fraction (VF) of perovskite (CaO·¤TiO_2) crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe_2O_3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF_2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.

关键词： perovskite phase Ti-bearing blast furnace slag precipitation additive agent

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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An explicit solution to a three-dimensional wedge problem considering two edges effect

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Friction 2020年第2期8卷 370-383页

作者： L.guo z.M.zHANG W.WANG Y.zHAO p.L.WONG School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444China Department of Mechanical Engineering City University of Hong KongHong Kong SARChina

The paper presents an explicit matrix algorithm to solve the problem of an elastic wedge with three loaded *** algorithm makes use of a recently published concept of transformation matrix,by which the original surface loads are converted to equivalent loads in *** three loaded edges are considered *** developed algorithm is used to study the effects of two free edges of a steel block and tapered rollers with different contact *** two load-free edges can substantially increase deformation if the two edges are close in *** results of the tapered roller simulation show that deformation is considerably sensitive to the contact angle of the tapered *** largest deformation appears at the big end of the ***,empirical formulae for correction factors for the calculation of block or quarter-space deformation based on half-space solutions are summarized.

关键词： contact mechanics two edge surfaces finite line contact tapered roller contact