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Wear behavior of copper material removal during fluid jet polishing:A comparative study between experiment and simulation

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Friction 2024年第8期12卷 1680-1695页

作者： Wenjing ZHANG Xin ZHANG Tiancheng ai Dan guo guoshun PAN State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Guangdong Provincial Key Laboratory of Optomechatronics Shenzhen 518057China

As a crucial part in micro-electromechanical manufacture,local ultra-precision processing of highly ductile copper is expected to be realized by fluid jet polishing(FJP),which widely utilized in optical *** copper exhibits different wear behavior from stiff and brittle material,there is currently no abrasive wear prediction model applicable for copper to investigate the polishing *** research reveals that the copper material removal is dominated by deformation wear rather than cutting wear through abrasive jet impact experiments and localized wear scars analysis.A three-dimensional gas-liquid-particle triphasic wear model for copper in FJP is developed by considering impact energy and wear mechanism ***,validation assessments at various working pressures and impingement angles achieve the goodness-of-fit up to 0.92–0.97 in quantitative comparison between simulations and experimental measurements,which demonstrate the wear prediction ability of the proposed *** investigation facilitates a better understanding of copper wear mechanism and provides theoretical guidance for FJP process optimization.

关键词： fluid jet polishing(FJP) wear mechanism computational fluid mechanics wear model material removal

A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： ai-guo WU Guang-Ren DUAN Yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

Global Phase Portraits of Uniform Isochronous Centers System of Degree Six with Polynomial Commutator

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 577-599页

作者： Li-na guo ai-yong CHEN Shuai-feng ZHAO School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang 471023China Department of Mathematics Hunan First Normal UniversityChangsha 410205China School of Mechatronics Engineering Henan University of Science and TechnologyLuoyang 471023China

This paper studies the global phase portraits of uniform isochronous centers system of degree six with polynomial *** systems have the form x=-y+xf(x,y),y=x+yf(x,y),where f(x,y)=a_(1)x+a_(2)xy+a_(3)xy^(2)+a_(4)xy^(3)+a_(5)xy^(4)=xσ(y),and any zero of 1+a_(1)y+a_(2)y^(2)+a_(3)y^(3)+a_(4)y^(4)+a_(5)y^(5),y=y is an invariant straight *** last,all global phase portraits are drawn on the Poincare disk.

关键词： global phase portraits uniform isochronous center polynomial commutator invariant straight lines

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Runout prediction of potential landslides based on the multi-source data collaboration analysis on historical cases

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China Geology 2024年第2期7卷 264-276页

作者： Jun Sun Yu Zhuang ai-guo Xing Guizhou Geology and Mineral Engineering Construction Co. LtdGuiyang 550000China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Long runout landslides involve a massive amount of energy and can be extremely hazardous owing to their long movement distance,high mobility and strong destructive *** methods have been widely used to predict the landslide runout but a fundamental problem remained is how to determine the reliable numerical *** study proposes a framework to predict the runout of potential landslides through multi-source data collaboration and numerical analysis of historical landslide ***,for the historical landslide cases,the landslide-induced seismic signal,geophysical surveys,and possible in-situ drone/phone videos(multi-source data collaboration)can validate the numerical results in terms of landslide dynamics and deposit features and help calibrate the numerical(rheological)***,the calibrated numerical parameters can be used to numerically predict the runout of potential landslides in the region with a similar geological setting to the recorded *** of the runout prediction approach to the 2020 Jiashanying landslide in Guizhou,China gives reasonable results in comparison to the field *** numerical parameters are determined from the multi-source data collaboration analysis of a historical case in the region(2019 Shuicheng landslide).The proposed framework for landslide runout prediction can be of great utility for landslide risk assessment and disaster reduction in mountainous regions worldwide.

关键词： Landslide runout prediction Drone survey Multi-source data collaboration DAN3D numerical modeling Jianshanying landslide Guizhou Province Geological hazards survey engineering

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Clinical Analysis and Mental Health Survey of Hemophilia Carriers:a Cross-sectional Study

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Current Medical Science 2024年第2期44卷 435-440页

作者： Wen WANG Li-juan JIANG Dong-yan CUI ai ZHANG Xiong WANG ai-guo LIU Qun HU Department of Pediatrics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Laboratory Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective:Hemophilia carriers(HCs),who are heterozygous for mutations in the clotting factor VIII/clotting factor IX gene(F8 or F9),may have a wide range of clotting factor levels,from very low,similar to afflicted males,to the upper limit of normal,and may experience mental health *** purpose of this study was to provide genetic information on mothers of hemophilia patients and to understand the clotting factor activity and phenotype of ***,we aimed to investigate the mental health status of HCs in ***:A total of 127 hemophilia mothers,including 93 hemophilia A(HA)mothers and 34 hemophilia B(HB)mothers,were enrolled in this *** distance PCR,multiplex PCR,and Sanger sequencing were used to analyze mutations in F8 or *** factor activity was detected by a one-stage clotting *** Symptom Checklist 90(SCL-90,China/Mandarin version)was given to HCs at the same time to assess their mental ***:A total of 90.6%of hemophilia mothers were diagnosed genetically as carriers,with inversion in intron 22 and missense mutations being the most common mutation types in HA and HB carriers,*** median clotting factor level in carriers was 0.74 IU/mL(ranging from 0.09 to 1.74 IU/mL)compared with 1.49 IU/mL(ranging from 0.93 to 1.89 IU/mL)in noncarriers,of which 14.3%of HCs had clotting factor levels of 0.40 IU/mL or below.A total of 53.8%(7/13)of HA carriers with low clotting factor levels(less than 0.50 IU/mL)had a history of bleeding,while none of the HB carriers displayed a bleeding *** total mean score and the global severity index of the SCL-90 for surveyed HCs were 171.00(±60.37)and 1.78(±0.59),respectively.A total of 67.7%of the respondents had psychological symptoms,with obsessive-compulsive disorder being the most prevalent and *** pooled estimates of all nine factors were significantly higher than those in the general population(P<0.05).Conclusions:The detection rate of gene mutations

关键词： hemophilia A hemophilia B mutation carrier mental health

Developmental regulation of PSD-95 and nNOS expression in lumbar spinal cord of rats

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Developmental regulation of PSD-95 and nNOS expression in lu...

Epigenetic silencing schlafen-11 sensitizes esophageal cancer to ATM inhibitor

中国神经科学学会第四次会员代表大会暨第八届全国学术会议

作者： Shang-Feng GAO~(1 2) ai-guo shen~2 Chun CHENG~(2 *) 1 Department of Neurobiology Institute for Neuroscience Zhejiang University School of Medicine Hangzhou 310058 China 2 Department of Microbiology and Immunology Medical School of Nantong University Nantong 226001 China

＜正＞Postsynaptic density（PSD）-95 is originally isolated from glutamatergic synapse where it serves as a physical tether to allow neuronal nitric oxide synthase（nNOS） signaling by N-methyl-D-aspartate receptor（NMDAR） activity. Considering the physiological importance of glutamate receptor and nitric oxide（NO） during development,we examined the spatiotemporal expression of PSD-95 and nNOS in the lumbar spinal cord at a postnatal ***,both gene and protein levels of them gradually increased with age after birth,peaked at the postnatal day 14（P14）,and then decreased to an adult *** addition,the enhanced coimmunoprecipitations between PSD-95 and nNOS were detected in developing spinal ***,PSD-95 staining codistributed with nNOS in NeuN-positive motor neurons and sensory neurons at *** findings indicate that PSD-95 and nNOS might collectively participate in spinal cord development.

关键词： post-synaptic density-95 neuronal nitric oxide synthase postnatal development spinal cord rat coimmunoprecipitation immunofluorescence

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2060-2073页

作者： Jing Zhou Mei-Ying Zhang ai-ai Gao Cheng Zhu Tao He James G Herman Ming-Zhou guo School of Medicine NanKai UniversityTianjin 300071China Department of Gastroenterology and Hepatology The First Medical CenterChinese PLA General HospitalBeijing 100853China Departments of Pathology Characteristic Medical Center of The Chinese People’s Armed Police ForceTianjin 300162China The Hillman Cancer Center University of Pittsburgh Cancer InstitutePittsburghPA 15213United States National Key Laboratory of Kidney Diseases Chinese PLA General HospitalBeijing 100853China

BACKGROUND Targeting DNA damage response(DDR)pathway is a cutting-edge *** has been reported that Schlafen-11(SLFN11)contributes to increase chemosensitivity by participating in ***,the detailed mechanism is *** To investigate the role of SLFN11 in DDR and the application of synthetic lethal in esophageal cancer with SLFN11 *** To reach the purpose,eight esophageal squamous carcinoma cell lines,142 esophageal dysplasia(ED)and 1007 primary esophageal squamous cell carcinoma(ESCC)samples and various techniques were utilized,including methylationspecific polymerase chain reaction,CRISPR/Cas9 technique,Western blot,colony formation assay,and xenograft mouse *** Methylation of SLFN11 was exhibited in 9.15%of(13/142)ED and 25.62%of primary(258/1007)ESCC cases,and its expression was regulated by promoter region ***11 methylation was significantly associated with tumor differentiation and tumor size(both P2 signaling *** silencing of SLFN11 was found to sensitize the ESCC cells to ATM inhibitor(AZD0156),both in vitro and in *** SLFN11 is frequently methylated in human *** of SLFN11 is sensitive marker of ATM inhibitor in ESCC.

关键词： Schlafen-11 Esophageal squamous cell carcinoma DNA methylation Synthetic lethality AZD0156

Rattling-like behavior and band convergence induced ultra-low lattice thermal conductivity in MgAl_(2)Te_(4) monolayer

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Journal of Materiomics 2024年第5期10卷 1004-1016页

作者： Da Wan Shulin Bai Xiaodong Li Jingyi Zhang Peng ai Wanrong guo Shuwei Tang College of Materials Science and Engineering Liaoning Technical UniversityFuxinLiaoning123000China Faculty of Chemistry Northeast Normal UniversityChangchunJilin130024China

Inspired by the excellent stability exhibited by experimentally synthesized two-dimensional(2D)MoSi_(2)N_(4) layered material,the thermal and electronic transport,and thermoelectric(TE)properties of MgAl2Te4 monolayer are systematically investigated using the First-principles calculations and Boltzmann transport *** mechanical stability,dynamic stability,and thermal stability(900 K)of the MgAl_(2)Te_(4) monolayer are demonstrated,*** MgAl_(2)Te_(4) monolayer exhibits a bandgap of 1.35 eV using the HSE06 functional in combination with spin-orbit coupling(SOC)*** convergence in the valence band is favorable to improve the thermoelectric *** rattling thermal damping effect caused by the weak bonding of Mgsingle bondTe bonds in MgAl2Te4 monolayer leads to ultra-low lattice thermal conductivity(0.95/0.38 W/(m·K)@300 K along the x-/y-direction),which is further demonstrated by the phonon group velocities,phonon relaxation time,Grüneisen parameters,and scattering *** optimal zT of 3.28 at 900 K is achieved for the p-type MgAl_(2)Te_(4) monolayer,showing the great promising prospect for the excellent p-type thermoelectric *** current work not only reveals the underlying mechanisms responsible for the excellent TE properties,but also elaborates on the promising thermoelectric application of MgAl_(2)Te_(4) monolayer material at high temperature.

关键词： Thermoelectric material Mg atomic rattling Band convergence Ultra-low lattice thermal conductivity

Attitude Tracking Control for Rigid Spacecraft with Arbitrary Convergence Time

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Journal of Systems Science & Complexity 2024年

作者： XU Yu-Tian WU ai-guo Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology (Shenzhen) Key University Laboratory of Mechanism & Machine Theory and Intelligent Unmanned Systems of Guangdong Harbin Institute of Technology (Shenzhen) Department of Automation Harbin Institute of Technology (Shenzhen) Shenzhen 518055 China4HIT Wuhu Robot Technology Research Institute

In this paper, attitude tracking control with arbitrary convergence time for rigid spacecraft is considered. First, a novel time-varying sliding function is proposed to achieve free-will arbitrary time convergence when the system states reside on the sliding surface. With such a sliding function, an attitude tracking controller is designed to guarantee that the states of the closed-loop system converge to the sliding surface within a predetermined time in the presence of external disturbances. The free-will arbitrary time convergences of the closed-loop system and sliding function are illustrated by numerical simulations.

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