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Indentation behavior of a semi-infinite piezoelectric semiconductor under a rigid flat-ended cylindrical indenter

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 649-662页

作者： Shijing gao Lele ZHANG Jinxi LIU Guoquan NIE Weiqiu CHEN State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Hebei Key Laboratory for Mechanics of Intelligent Materials and Structures Department of Engineering MechanicsShijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Computer Aided Design and Computer Graphics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceDepartment of Engineering MechanicsZhejiang UniversityHangzhou 310027China

This paper theoretically studies the axisymmetric frictionless indentation of a transversely isotropic piezoelectric semiconductor(PSC)half-space subject to a rigid flatended cylindrical *** contact area and other surface of the PSC half-space are assumed to be electrically *** the Hankel integral transformation,the problem is reduced to the Fredholm integral equation of the second *** equation is solved numerically to obtain the indentation behaviors of the PSC half-space,mainly including the indentation force-depth relation and the electric potential-depth *** results show that the effect of the semiconductor property on the indentation responses is limited within a certain range of variation of the steady carrier *** dependence of indentation behavior on material properties is also analyzed by two different kinds of *** element simulations are conducted to verify the results calculated by the integral equation technique,and good agreement is demonstrated.

关键词： piezoelectric semiconductor(PSC) insulating indenter electromechanical response singular integral equation finite element simulation

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Smart Gait:A Gait Optimization Framework for Hexapod Robots

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 146-159页

作者： Yunpeng Yin Feng gao Qiao Sun Yue Zhao Yuguang Xiao State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Lenovo Corporation ShanghaiChina AI Institute School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The current gait planning for legged robots is mostly based on human presets,which cannot match the flexible characteristics of natural *** paper proposes a gait optimization framework for hexapod robots called Smart *** Gait contains three modules:swing leg trajectory optimization,gait period&duty optimization,and gait sequence *** full dynamics of a single leg,and the centroid dynamics of the overall robot are considered in the respective *** Smart Gait not only helps the robot to decrease the energy consumption when in locomotion,mostly,it enables the hexapod robot to determine its gait pattern transitions based on its current state,instead of repeating the formalistic clock-set step *** Smart Gait framework allows the hexapod robot to behave nimbly as a living animal when in 3D movements for the first *** Smart Gait framework combines offline and online optimizations without any fussy data-driven training procedures,and it can run efficiently on board in real-time after *** experiments are carried out on the hexapod robot *** results show that the energy consumption is reduced by 15.9%when in *** gait patterns can be generated spontaneously both in regular and challenge environments,and when facing external interferences.

关键词： Gait optimization Swing trajectory optimization Legged robot Hexapod robot

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Repeatability and reproducibility of corneal higher-order aberrations measurements after small incision lenticule extraction using the Scheimpfug-Placido topographer

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Eye and Vision 2024年第1期10卷 1-9页

作者： Rui Ning Rongrong gao David PPiñero Jun Zhang Qingyi gao Yili Jin Yiran Wang Chenxiao Wang Jinhai Huang Eye Hospital and School of Ophthalmology and Optometry Wenzhou Medical UniversityWenzhouZhejiangChina Eye Institute and Department of Ophthalmology Eye and ENT HospitalFudan UniversityShanghaiChina Group of Optics and Visual Perception Department of OpticsPharmacology and AnatomyUniversity of AlicanteAlicanteSpain NHC Key Laboratory of Myopia(Fudan University) Key Laboratory of MyopiaChinese Academy of Medical SciencesShanghaiChina Shanghai Research Center of Ophthalmology and Optometry ShanghaiChina

Background:To evaluate the precision of corneal higher-order aberrations measurements after small incision lenticule extraction(SMILE)using the Sirius Scheimpfug-Placido topographer(CSO,Italy).Methods:Seventy-fve eyes from 75 postoperative subjects were included in this prospective *** consecutive corneal aberrometric measurements were obtained with the Scheimpfug-Placido topographer by two experienced operators to assess intra-and inter-observer *** within-subject standard deviation(Sw),test-retest repeatability(TRT)and the intraclass correlation coefcient(ICC)were ***:For intraobserver repeatability of anterior and total corneal aberrations,all ICCs were more than 0.922,except for trefoil(0.722 to 0.768).The ICCs of total root mean square(RMS),coma Z(3,±1),and spherical aberration Z(4,0)were over 0.810 while higher-order RMS,trefoil Z(3,±3),and astigmatism II Z(4,±2)were below 0.634 for posterior corneal surface *** Sw values for all types of aberrations were equal to or below 0.07μ*** interobserver reproducibility,all TRT values were no more than 0.12μm,0.05μm,and 0.11μm for anterior,posterior,and total corneal aberrations,*** ICC values ranged from 0.875 to 0.989,from 0.686 to 0.976 and over 0.834 for anterior,posterior,and total corneal aberrations,***:The repeatability of measurements of anterior and total corneal aberrations with the Sirius system in corneas after SMILE surgery was high,except for *** was some variability in posterior corneal aberrometric *** reproducibility of corneal aberrometric measurements was observed between measurements of both examiners,except for trefoil,with poor to moderate reproducibility.

关键词： Sirius Higher-order aberrations Repeatability Reproducibility Small incision lenticule extraction

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Application of immune checkpoint inhibitors and microsatellite instability in gastric cancer

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World Journal of Gastroenterology 2024年第21期30卷 2734-2739页

作者： Shi-Yan Yan Jian-gao Fan Department of Gastroenterology Xinhua HospitalShanghai Jiaotong University School of MedicineShanghai 200092China

In this editorial we comment on the article by Li published in the recent issue of the World Journal of *** focus specifically on the application of immune checkpoint inhibitors(ICIs)and microsatellite instability(MSI)in gastric cancer(GC).The four pillars of GC management have long been considered,including surgery,chemotherapy,radiotherapy and targeted ***,immunotherapy has recently emerged as a“fifth pillar”,and its use is rapidly *** are four principal strategies for tumor immunotherapy:ICIs,tumor vaccines,adoptive immunotherapy and nonspecific *** them,ICIs are the most advanced and widespread type of cancer immunotherapy for *** breakthrough results for ICIs have paved the way to a new era of cancer *** particular,inhibition of the PD-1/PD-L1 axis with ICIs,including nivolumab and pembrolizumab,has emerged as a novel treatment strategy for advanced ***,these therapies are sometimes associated with often subtle,potentially fatal immune-related adverse events(irAEs),including dermatitis,diarrhea,colitis,endocrinopathy,hepatotoxicity,neuropathy and *** must be aware of these irAEs and improve the detection of these processes to prevent inappropriate discharges,emergency department revisits,and downstream *** studies have revealed that MSI-high or mismatch-repair-deficient tumors,regardless of their primary site,have a promising response to ***,it is important to detect MSI before applying ICIs for treatment of GC.

关键词： Gastric cancer Immune checkpoint inhibitors Microsatellite instability Immunotherapy Immune-related adverse events

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High-sensitivity photonic crystal fiber sensor based on surface plasmon resonance

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Optoelectronics Letters 2024年第7期20卷 393-399页

作者： FENG Huanting gao Jiachen MING Xianbing School of Physical Science and Technology Tiangong UniversityTianjin 300387China1

In this paper,we propose a photonic crystal fiber(PCF)sensor based on the surface plasmonic resonance(SPR)effect for simultaneous temperature and refractive index(RI)*** coupling characteristics and sensing performance of the sensor are analyzed using the full vector finite element method(FEM).The sensor provides two channels for independent measurement of RI and *** operating independently,channel I supports y-polarized light with a sensitivity of up to 7000 nm/RIU for detecting RI,while channel II supports x-polarized light with a sensitivity of up to 16 nm/℃for detecting ***,we investigate the influence of gold layer thickness on the sensing performance to optimize the sensor.

关键词： temperature measurement fiber

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Jet Characteristics and Optimization of a Cavitation Nozzle for Hydraulic Fracturing Applications

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Fluid Dynamics & Materials Processing 2024年第1期20卷 179-192页

作者： Yu gao Zhenqiang Xu Kaixiang Shen Shenzhen South China Sea Oil Economic Development Co. Ltd.Shenzhen518000China Guangzhou Marine Geological Survey China Geological SurveyGuangzhou511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou511458China

Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation *** this study,the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ωturbulence *** results show that the nozzle structure can significantly influence the jet performance and related cavitation *** orthogonal experiments,the nozzle geometric parameters are optimized,and the following configuration is found accordingly:contraction angle 20°,contraction segment length 6 mm,cylindrical segment diameter 6 mm,cylindrical segment length 12 mm,spread segment length 10 mm,and spread angle 55°.

关键词： Cavitation jet angle nozzle hydraulic characteristics nozzle parameters

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Determination of the Pile Drivability Using Random Forest Optimized by Particle Swarm Optimization and Bayesian Optimizer

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 871-892页

作者： Shengdong Cheng Juncheng gao Hongning Qi State Key Laboratory of Eco-Hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an710048China School of Resources and Safety Engineering Central South UniversityChangsha410083China

Driven piles are used in many geological environments as a practical and convenient structural ***,the determination of the drivability of piles is actually of great importance in complex geotechnical *** methods of predicting pile drivability often rely on simplified physicalmodels or empirical formulas,whichmay lack accuracy or applicability in complex geological ***,this study presents a practical machine learning approach,namely a Random Forest(RF)optimized by Bayesian Optimization(BO)and Particle Swarm Optimization(PSO),which not only enhances prediction accuracy but also better adapts to varying geological environments to predict the drivability parameters of piles(i.e.,maximumcompressive stress,maximum tensile stress,and blow per foot).In addition,support vector regression,extreme gradient boosting,k nearest neighbor,and decision tree are also used and applied for comparison *** order to train and test these models,among the 4072 datasets collected with 17model inputs,3258 datasets were randomly selected for training,and the remaining 814 datasets were used for model ***,the results of these models were compared and evaluated using two performance indices,i.e.,the root mean square error(RMSE)and the coefficient of determination(R2).The results indicate that the optimized RF model achieved lower RMSE than other prediction models in predicting the three parameters,specifically 0.044,0.438,and 0.146;and higher R^(2) values than other implemented techniques,specifically 0.966,0.884,and *** addition,the sensitivity and uncertainty of the optimized RF model were analyzed using Sobol sensitivity analysis and Monte Carlo(MC)*** can be concluded that the optimized RF model could be used to predict the performance of the pile,and it may provide a useful reference for solving some problems under similar engineering conditions.

关键词： Random forest regression model pile drivability Bayesian optimization particle swarm optimization

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Influence of sintering time on microstructure and properties of hot oscillatory pressing sintered W–Cu refractory alloys

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Tungsten 2024年第2期6卷 323-332页

作者： Zi-Qian Wu Wei Zhao Ka gao Shi-Hao Du Qing-Quan Kong De-Jian Sun Yang gao School of Materials Science and Engineering Zhengzhou University of AeronauticsZhengzhou 450015China School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China Department of General Medicine Changhai HospitalShanghai 200000China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan 430081China Sichuan Province Engineering Technology Research Center of Powder Metallurgy Chengdu UniversityChengdu 610106China

W–Cu refractory alloys are widely used in aerospace,aviation,electronics,power,and other fi ***,because of its large melting point diff erence between alloy elements,the conventional powder metallurgy method required a long time of high temperature sintering is very likely to cause low density and abnormal grain size ***,90W-10Cu refractory alloys were successfully prepared by hot oscillatory pressing(HOP)under diff erent sintering time in this *** the infl uence of sintering time on the microstructure,grain size,density,Vickers hardness,room-tensile property,and electrical conductivity of the W–Cu refractory alloy was systematically *** results showed that during the short sintering time(30–90 min),the density,Vickers hardness,tensile strength,and electrical conductivity of the W–Cu refractory alloy increased signifi cantly to 98.7%,163.29 HV 30,507.3 MPa,and 14.2%International Annealed Copper Standard with the sintering time increasing,respectively,while its grain size showed no obvious *** the sintering time further increased to 120 min,the density was basically consistent with the sintering time of 90 ***,the prolonged high temperature sintering resulted in the grain growth of the samples,which caused the deterioration of the Vickers hardness,room-tensile strength,and conductivity properties of the W–Cu refractory *** the same sintering time,the density,Vickers hardness,and electrical conductivity of the HOP sintered W–Cu refractory alloy were signifi cantly higher than those of the HP sintered *** was indicated that high density,fi ne-grain,and excellent properties W–Cu refractory alloys could be prepared by hot oscillatory pressing under appropriate sintering time.

关键词： W–Cu refractory alloy Hot oscillatory pressing Sintering time Microstructure Property

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一种改良微创人工晶状体固定术的临床观察

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国际眼科杂志 2024年第6期24卷 980-984页

作者：赵瑞苓王兵唐蕾蕾高峰中国山东省滕州市中心人民医院眼科 277599

目的:观察隐形锚钩式巩膜层间人工晶状体固定术的临床效果。方法:前瞻性非对照性病例研究。选取2019-01/2020-12我院收治的无晶状体、人工晶状体脱位或晶状体脱位患者19例19眼,所有患者均接受锚钩式人工晶状体巩膜层间固定植入手术。观... 详细信息

目的:观察隐形锚钩式巩膜层间人工晶状体固定术的临床效果。方法:前瞻性非对照性病例研究。选取2019-01/2020-12我院收治的无晶状体、人工晶状体脱位或晶状体脱位患者19例19眼,所有患者均接受锚钩式人工晶状体巩膜层间固定植入手术。观察手术前后最佳矫正视力(BCVA)、裸眼视力(UCVA)、角膜内皮细胞密度、术后人工晶状体位置有无倾斜和并发症。结果:术前和术后1 mo,UCVA(LogMAR)为1.06±0.63和0.40±0.26(P<0.01),BCVA(LogMAR)为0.27±0.51和0.06±0.15(P=0.09),角膜内皮细胞密度为2406±625和2004±759 cells/mm~2(P=0.13)。术后1d房水闪辉2级或以上3眼,角膜后弹力层皱褶2眼,一过性眼压升高2眼。随访24 mo均未发生人工晶状体脱位。结论:锚钩式人工晶状体巩膜层间固定技术,组织间线头顺行进入-逆向固定,类似锚钩原理,达到了良好的人工晶状体稳定性和视觉效果。

关键词：巩膜层间人工晶状体固定锚钩缝线脱位

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Banxia Xiexin Decoction Alleviated Cerebral Glucose Metabolism Disorder by Regulating Intestinal Microbiota in APP/PS1 Mice

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Chinese Journal of Integrative Medicine 2024年第8期30卷 701-712页

作者： gao Chen-yan QIN gao-feng ZHENG Ming-cui TIAN Mei-jing HE Yan-nan WANG Peng-wen Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing Dongzhimen HospitalBeijing University of Chinese MedicineBeijing100700China Neurology Department Binzhou Medical University HospitalBinzhouShandong Province256603China

Objective To identify whether Banxia Xiexin Decoction(BXD)alleviates cerebral glucose metabolism disorder by intestinal microbiota regulation in APP/PS1 *** Forty-five 3-month-old male APP/PS1 mice were divided into 3 groups using a random number table(n=15 per group),including a model group(MG),a liraglutide group(LG)and a BXD group(BG).Fifteen 3-month-old male C57BL/6J wild-type mice were used as the control group(CG).Mice in the BG were administered BXD granules by gavage at a dose of 6 g/(kg·d)for 3 months,while mice in the LG were injected intraperitoneally once daily with Liraglutide Injection(25 nmol/kg)for 3 ***,liquid chromatography with tandem-mass spectrometry was used to analyze the active components of BXD granules and the medicated serum of ***,the cognitive deficits,Aβpathological change and synaptic plasticity markers,including synaptophysin(SYP)and postsynaptic density protein 95(PSD95),were measured in APP/PS1 *** glucose uptake was detected by micropositron emission *** microbial constituents were detected by 16S rRNA *** levels of intestinal glucagon-like peptide 1(GLP-1)and cerebral GLP-1 receptor(GLP-1R),as well as the phosphoinositide-3-kinase/protein kinase B/glycogen synthase kinase-3β(PI3K/Akt/GSK3β)insulin signaling pathway were determined by immunohistochemical(IHC)staining and Western blot analysis,*** BXD ameliorated cognitive deficits and Aβpathological features(P<0.01).The expressions of SYP and PSD95 in the BG were higher than those in the MG(P<0.01).Brain glucose uptake in the BG was higher than that in the MG(P<0.01).The intestinal microbial composition in the BG was partially *** levels of intestinal GLP-1 in the BG were higher than those in the MG(P<0.01).Compared with the MG,the expression levels of hippocampal GLP-1R,Akt,PI3K and p-PI3K in the BG were significantly increased(P<0.01),while the levels of GSK3βwere reduced(P<0.01).Conclusion BXD

关键词： Banxia Xiexin Decoction Alzheimer's disease intestinal microbiota glucagon-like peptide 1 cerebral insulin resistance phosphoinositide-3-kinase/proteinkinase B/glycogen synthase kinase-3β Chinese medicine

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