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Journal of Materials Science & Technology 2005年第5期21卷 691-700页

作者： jun zhang qian LIU Lin WANG Department of Civil Engineering Tsinghua University Beijing 100084 China

Fine and coarse aggregates play an important role in the fracture of concrete. However, quantitative information available on the effect of the coarse aggregate size on the fracture properties of concrete is still limited. In the present paper, the effect of coarse aggregate size （single grade of 5～10, 10～16, 16～20 and 20～25 mm） on stress-crack opening （σ-w） relation in normal and high strength concretes （compressive strength of 40 and 80 MPa, respectively） was studied. The investigation was based on three-point bending tests implemented by fictitious crack analysis. The result shows that coarse aggregate size and cement matrix strength significantly influence the shape of σ-w curve. For a given total aggregate content, in normal strength concrete, smaller size of aggregate leads to a high tensile strength and a sharp stress drop after the peak stress. The smaller the coarse aggregate, the steeper the σ-w curve. By contrast, in high strength concrete, the effect of aggregate size on σ-w relation almost vanishes. A similar σ-w relation is obtained for the concrete except for the case of 20～25 mm coarse aggregate size. The stress drop after the peak stress is more significant for high strength concrete than that for normal strength concrete. Meanwhile, the smaller the coarse aggregate size, the higher the flexural strength. Fracture energy and characteristic length increase with increasing coarse aggregate size in both normal and high strength concretes.

关键词： Aggregate size Stress-crack opening relation Fracture energy Bending test

Two-dimensional analysis of progressive delamination in thin film electrodes

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Acta Mechanica Sinica 2018年第2期34卷 359-370页

作者： Mei Liu Bo Lu Dong-Li Shi jun-qian zhang Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Department of Mechanics Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University Materials Genome Institute Shanghai University

By employing the two-dimensional analysis, i.e.,plane strain and plane stress, a semi-analytical method is developed to investigate the interfacial delamination in electrodes. The key parameters are obtained from the governing equations, and their effects on the evolution of the delamination are evaluated. The impact of constraint perpendicular to the plane is also investigated by comparing the plane strain and plane stress. It is found that the delamination in the plane strain condition occurs easier, indicating that the constraint is harmful to maintain the structure stability. According to the obtained governing equations, a formula of the dimensionless critical size for delamination is provided, which is a function of the maximum volumetric strain and the Poisson’s ratio of the active layer.

关键词： Lithium-ion battery Thin film electrode Delamination Critical size

The Setting of Boundary Conditions for Boundary Value Problems of Hyperbolic-elliptic Coupled Systems

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 375-390页

作者： Shu-xing Chen Ze-jun Wang Yong-qian zhang School of Mathematical Sciences Fudan University Shanghai 200433 China

This paper is devoted to the study of the proper setting of the boundary conditions for the boundary value problems of the hyperbolic-elliptic coupled systems of first order. The wellposedness of the corresponding boundary value problems is also established. The Lopatinski conditions for the boundary value problems of the elliptic systems is then extended to the case for hyperbolic-elliptic coupled systems. The result in this paper can be applied to the Euler system in fluid dynamics, especially to give wellposed boundary value problems describing subsonic flow.

关键词： Boundary value problems hyperbolic-elliptic coupled systems pseudo-differential operators

Analysis of delamination in thin film electrodes under galvanostatic and potentiostatic operations with Li-ion diffusion from edge

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Acta Mechanica Sinica 2013年第3期29卷 348-356页

作者： Bo Lu Yi-Cheng Song Zhan-Sheng Guo jun-qian zhang Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Department of Mechanics Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University

Progressive delamination driven by Li-ion diffusion in elastic disk-like thin film electrodes of Li-ion batteries is modeled based on the cohesive model. Axisymmetric diffusion model is considered under both galvanostatic and potentiostatic operations. The effect of edge diffusion on the delamination process is evaluated. It is found that the diffusion from edge leads to an earlier delamination initiation. The edge effect is significant for active disks with a small aspect ratio, but negligible for the case of large aspect ratio. The edge diffusion is weaker in the potentiostatic operation than in the galvanostatic operation.

关键词： Lithium-ion battery · Thin film electrode · De-lamination · Diffusion

Two missense STK11 gene variations impaired LKB1/adenosine monophosphate-activated protein kinase signaling in Peutz-Jeghers syndrome

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1532-1546页

作者： Jin Liu Si-Cong Zeng An Wang Hai-Ying Cheng qian-jun zhang Guang-Xiu Lu Hunan Guangxiu Hospital Hunan Normal UniversityChangsha 410000Hunan ProvinceChina Scientific Research Department Reproductive and Genetic Hospital of Citic-XiangyaChangsha 410000Hunan ProvinceChina

BACKGROUND Peutz-Jeghers syndrome(PJS)is a rare hereditary neoplastic disorder mainly associated with serine/threonine kinase 11(STK11/LKB1)gene *** genetic testing can protect a patient’s offspring from mutated genes;however,some variations in this gene have been interpreted as variants of uncertain significance(VUS),which complicate reproductive decision-making in genetic *** To identify the pathogenicity of two missense variants and provide clinical *** Whole exome gene sequencing and Sanger sequencing were performed on the peripheral blood of patients with PJS treated at the Reproductive and Genetic Hospital of *** was employed to predict the protein structure,conservation,and pathogenicity of the two missense variation sites in patients with ***,plasmids were constructed and transfected into HeLa cells to observe cell *** differences in signal pathway expression between the variant group and the wild-type group were compared using western blot and *** analysis was performed using one-way analysis of variance.PG(***297Gly)and c.733C>T(***245Phe)]in 9 unrelated PJS families who were seeking reproductive *** two missense VUS were located in the catalytic domain of serine/threonine kinase,which is a key structure of the liver kinase B1(LKB1)*** vitro experiments showed that the phosphorylation levels of adenosine monophosphate-activated protein kinase(AMPK)at Thr172 and LKB1 at Ser428 were significantly higher in transfected variation-type cells than in wild-type *** addition,the two missense STK11 variants promoted the proliferation of HeLa *** immunohistochemical analysis showed that phosphorylated-AMPK(Thr172)expression was significantly lower in gastric,colonic,and uterine polyps from PJS patients with misse

关键词： Missense STK11 Peutz-Jeghers syndrome Rare disease Genetic counseling Assisted reproductive technique

A Novel Sesquiterpenoid from Glechoma longituba

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Chinese Chemical Letters 2006年第3期17卷 355-357页

作者： qian jun zhang Xiao Sheng YANG Hal Yan ZHU Ye WANG Xiao Jiang HAO Bao An SONG The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academy of Sciences Guiyang 550002 Research and Development Center of Fine Chemicals Guizhou Univerisity Guiyang 550025

A novel sesquiterpenoid was isolated from the whole plant of Glechoma longituba. Its structure was elucidated as 1, 8-epoxy-7（11）-germacren-5-one-12, 8-olide 1 on the basis of spectral evidences.

关键词： Glechoma longituba sesquiterppenoid 1,8-epoxy-7(11)-germacren-5-one- 12,8-olide

Sperm flagellar 2(SPEF2)is essential for sperm flagellar assembly in humans

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Asian Journal of Andrology 2022年第4期24卷 359-366页

作者： Dong-Yan Li Xiao-Xuan Yang Chao-Feng Tu Wei-Li Wang Lan-Lan Meng Guang-Xiu Lu Yue-Qiu Tan qian-jun zhang Juan Du Institute of Reproductive and Stem Cell Engineering School of Basic Medical ScienceCentral South UniversityChangsha 410078China Clinical Research Center for Reproduction and Genetics in Hunan Province Reproductive and Genetic Hospital of CITIC-XiangyaChangsha 410078China

Spermiogenesis is a complex and tightly regulated process,consisting of acrosomal biogenesis,condensation of chromatin,flagellar assembly,and disposal of extra *** studies have reported that sperm flagellar 2(SPEF2)deficiency causes severe asthenoteratozoospermia owing to spermiogenesis failure,but the underlying molecular mechanism in humans remains ***,we performed proteomic analysis on spermatozoa from three SPEF2 mutant patients to study the functional role of SPEF2 during sperm tail development.A total of 1262 differentially expressed proteins were detected,including 486 upregulated and 776 *** constructed heat map of the differentially expressed proteins showed similar *** these,the expression of proteins related to flagellar assembly,including SPEF2,sperm associated antigen 6(SPAG6),dynein light chain tctex-type 1(DYNLT1),radial spoke head component 1(RSPH1),translocase of outer mitochondrial membrane 20(TOM20),EF-hand domain containing 1(EFHC1),meiosis-specific nuclear structural 1(MNS1)and intraflagellar transport 20(IFT20),was verified by western *** clustering analysis indicated that these differentially expressed proteins were specifically enriched for terms such as spermatid development and flagellar ***,we showed that SPEF2 interacts with radial spoke head component 9(RSPH9)and IFT20 in vitro,which are well-studied components of radial spokes or intra-flagellar transport and are essential for flagellar *** results provide a rich resource for further investigation into the molecular mechanism underlying the role that SPEF2 plays in sperm tail development and could provide a theoretical basis for gene therapy in SPEF2 mutant patients in the future.

关键词： SPEF2 flagellar assembly male infertility protein interaction proteomics

The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 275-282页

作者： GAO qian LI jun WANG Xianhui CAO Laifu GONG Jian LI Bo Central Iron and Steel Research Institute Group Beijing 100081China Shougang Zhixin Electromagnetic Material R&D(Beijing)Co. Ltd.Beijing 101300China Beijing Shougang Co. Ltd.Qian’an 064404China

Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing,in which the evolution of magnetic properties,grain orientations and precipitates were *** illustrate the Zener factor,the diameter and number density of precipitates of interrupted testing samples were statistically *** effect of precipitate ripening on the Goss texture and magnetic property was *** indicated that the trend of Zener factor was similar under different heating rates,first increasing and then decreasing,and that the precipitate maturing was greatly inhibited as the heating rate *** recrystallization was developed at the temperature of 1010℃when a heating rate of 5℃/h was used,resulting in Goss,Brass and{110}oriented grains growing abnormally and a magnetic induction intensity of ***,increasing the heating rate to 20℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss ***,when the heating rate was extremely fast,such as 40℃/h,poor secondary recrystallization was developed with many island grains,corresponding to a decrease in magnetic induction intensity to 1.87 *** a suitable heating rate of 20℃/h,the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1020℃were found among the experimental variables in this *** heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates,leading to the deviation and dispersion of Goss texture,thereby reducing the magnetic properties.

关键词： high temperature annealing heating rate secondary recrystallization grain oriented silicon steel

Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun zhang Shengtao Gao Xingzhao zhang Dacheng Ma Chuanlei Zhu jun He Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

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Journal of Energy Chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min Song Lulu An Xiao Huang qian zhang Chenhao zhang Tao Shen Shuang Wang Deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction *** loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic *** remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Synergistic effect Intermetallics Single atomic sites Oxygen reduction reaction Hydrogen evolution reaction