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A modified-Liutex-based vortex-core-line extractor and its application

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Journal of Hydrodynamics 2023年第4期35卷 811-824页

作者： Jin-yan Cai Dong Li Zi-ming Xu ze-yu zhang Jiao-lin Cui School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China High Speed Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang621000China

Vortices,which appear as swirling behaviour of a flow field,are an important phenomenon in fluid dynamics,and the extraction of vortex cores is necessary for the research of vortex evolution in many areas of fluid *** Liutex method is a milestone in vortex identification and provides a reasonable mathematical definition for a vortex *** on this definition,a novel integration-based method is presented,which can reduce the numerical error in the integration process through location *** typical test cases,the wake vortices of an A320 in the near-ground stage and a helicopter rotor,are examined to show that the proposed method can extract continuous vortex core lines with accuracy and efficiency for vortex parameter study.

关键词： Vortex definition flow visualization Liutex vortex core lines optimization

Estimation for nearly unit root processes with GARCH errors

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Applied Mathematics(A Journal of Chinese Universities) 2010年第3期25卷 297-306页

作者： yuAN yu-ze zhang Rong-mao Department of Mathematics, Zhejiang University, Hangzhou 310027, China Department of Mathematics Zhejiang University Hangzhou China

In this paper the limiting distribution of the least square estimate for the autoregressive coefficient of a nearly unit root model with GARCH errors is derived. Since the limiting distribution depends on the unknown variance of the errors, an empirical likelihood ratio statistic is proposed from which confidence intervals can be constructed for the nearly unit root model without knowing the variance. To gain an intuitive sense for the empirical likelihood ratio, a small simulation for the asymptotic distribution is given.

关键词： Nearly unit root GARCH error least square estimation Ornstein-Uhlenbeck process empirical likelihood.

Assessment of functional prognosis of anterior cruciate ligament reconstruction in athletes based on a body shape index

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World Journal of Clinical Cases 2023年第19期11卷 4567-4578页

作者： yun-Jun Wang Jun-Chang zhang yu-ze zhang Ying-Hai Liu Institutes of Biomedical Sciences Shanxi UniversityTaiyuan 030006Shanxi ProvinceChina Department of Orthopedics First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina

BACKGROUND A healthy body shape is essential to maintain athletes’sports *** present,little is known about the effect of athletes’body shape on anterior cruciate ligament reconstruction(ACLR).Moreover,the relationship between body shape and variables such as knee joint function after operation and return to the field has not been well *** To verify the relationship between a body shape index(ABSI)and the functional prognosis of the knee after ACLR in athletes with ACL *** We reviewed 76 athletes with unilateral ACL ruptures who underwent ACLR surgery in the First Hospital of Shanxi Medical University between 2017 and 2020,with a follow-up period of more than 24 ***,all populations were divided into a High-ABSI group(ABSI>0.835,n=38)and a Low-ABSI group(ABSIzed using multifactorial logistic *** The preoperative knee function scores of the two groups were *** surgery and postoperative rehabilitation exercises,range of motion(ROM)compliance rate,Lysholm score,and Knee Injury and Osteoarthritis Outcome Score of the two groups gradually increased,whereas the quadriceps atrophy index gradually *** knee function scores were higher in the Low-ABSI group than in the High-ABSI group at the 24-mo postoperative follow-up(P<0.05).In multifactorial logistic regression,ABSI was a risk factor of low knee joint function score after surgery,specifically low ROM scores(odds ratio[OR]=1.31,95%confidence interval[CI][1.10-1.44];P<0.001),low quadriceps atrophy index(OR=1.11,95%CI[0.97-1.29];P<0.05),low Lysholm scores(OR=2.34,95%CI[1.78-2.94];P<0.001),low symptoms(OR=1.14,95%CI[1.02-1.34];P<0.05),low activity of daily

关键词： A body shape index Anterior cruciate ligament reconstruction Athletes Multifactorial logistic regression Obesity

Polycystic liver disease: Classification, diagnosis, treatment process, and clinical management

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World Journal of Hepatology 2020年第3期12卷 72-83页

作者： ze-yu zhang Zhi-Ming Wang yun Huang Department of Hepatobiliary Surgery Xiangya HospitalCentral South UniversityChangsha 410000Hunan ProvinceChina

Polycystic liver disease(PLD)is a rare hereditary disease that independently exists in isolated PLD,or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease with complicated *** currently lacks a unified diagnostic *** diagnosis of PLD is usually made when the number of hepatic cysts is more than *** classification and Schnelldorfer classification are now commonly used to define severity in *** PLD patients have no clinical symptoms,and minority with severe complications need *** analogues,mammalian target of rapamycin inhibitor,ursodeoxycholic acid and vasopressin-2 receptor antagonist are the potentially effective medical therapies,while cyst aspiration and sclerosis,transcatheter arterial embolization,fenestration,hepatic resection and liver transplantation are the options of invasion ***,the effectiveness of these therapies except liver transplantation are still ***,there is no unified strategy to treat PLD between medical centers at *** order to better understand recent study progresses on PLD for clinical practice and obtain potential directions for future researches,this review mainly focuses on the recent progress in PLD classification,clinical manifestation,diagnosis and *** information,we also provided medical treatment processes of PLD in our medical center.

关键词： Polycystic liver disease Autosomal dominant polycystic kidney disease Autosomal recessive polycystic kidney disease Isolated polycystic liver disease Diagnosis Treatment

Micro defects formation and dynamic response analysis of steel plate of quasi-cracking area subjected to explosive load

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Defence Technology（防务技术） 2024年第1期31卷 580-593页

作者： Zheng-qing Zhou ze-chen Du Xiao Wang Hui-ling Jiang Qiang Zhou yu-long zhang yu-zhe Liu Pei-ze zhang Research Institute of Macro-Safety Science University of Science and TechnologyBeijing100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China School of Mechanical Engineering Nantong UniversityNantong226019China China North Industry Advanced Technology Generalization Institute Beijing100089China China Academy of Ordnance Science China

As the protective component,steel plate had attracted extensive attention because of frequently threats of explosive *** this paper,the evolution of microstructure and the mechanism of damage in the quasi-cracking area of steel plate subjected to explosive load were discussed and the relationships between micro defects and dynamic mechanical response were *** the explosion experiment,five observation points were selected equidistant from the quasi-cracking area of the section of the steel plate along the thickness direction,and the characteristics of micro defects at the observation points were analyzed by optical microscope(OM),scanning electron microscope(SEM) and electron backscattered diffraction(EBSD).The observation result shows that many slip bands(SBs) appeared,and the grain orientation changed obviously in the steel plate,the two were the main damage types of micro *** addition,cracks,peeling pits,grooves and other lager micro defects were appeared in the lower area of the *** stress parameters of the observation points were obtained through an effective numerical *** mechanism of damage generation and crack propagation in the quasicracking area were clarified by comparing the specific impulse of each observation point with the corresponding micro *** result shows that the generation and expansion of micro defects are related to the stress area(*** upper compression area,the neutral plane area,and the lower tension area).The micro defects gather and expand at the grain boundary,and will become macroscopic damage under the continuous action of tensile ***,the micro defects at the midpoint of the section of the steel plate in the direction away from the explosion center(*** horizontal direction) were also *** was found that the specific impulse at these positions were much smaller than that in the thickness direction,the micro defects were only SBs and a few micro cracks,and the those decrea

关键词： Explosive load Quasi-cracking area Micro defects Steel plate Dynamic response Numerical simulation

Sign reversal and manipulation of anomalous Hall resistivity in facing-target sputtered Pt/Mn_(4)N bilayers

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Rare Metals 2023年第2期42卷 591-601页

作者： ze-yu zhang Jia-Wei Jiang Xiao-Hui Shi Xiang Liu Xia Chen Zhi-Peng Hou Wen-Bo Mi Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology School of ScienceTianjin UniversityTianjin300354China School of Physics and Electronic Engineering Linyi UniversityLinyi276000China College of Science Civil Aviation University of ChinaTianjin300300China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology&Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China

The magnetic and electronic transport properties manipulated by spin-orbit torque have been devoted much attention as they show a great promise for future spintronic ***,the spin dependent transport properties of the facing-target sputtered Pt/Mn_(4)N bilayers on MgO(001)substrates have been investigated *** Hall resistivity of Pt/Mn_(4)N bilayers is strongly dependent on temperature,applied current intensity,Mn_(4)N and Pt layer *** temperature-dependent sign reversal of anomalous Hall resistivity appears in Pt/Mn_(4)N bilayers,which is dominated by the competition between the magnetic proximity and spin Hall ***,the magnitude of anomalous Hall resistivity can be manipulated by applied current *** critical and saturation currents are related to Mn_(4)N and Pt layer ***,a Dzyaloshinskii-Moriya interaction coefficient(D)of 5.63 mJ·m^(-2)is calculated in Pt/Mn_(4)N/MgO *** details of the anomalous Hall effects in Pt/Mn_(4)N bilayers are helpful to understand the interfacial effects between heavy metals and ferrimagnets.

关键词： Pt/Mn_(4)N bilayer Hall resistivity Magnetic proximity effect Spin Hall effect(SHE) DzyaloshinskiiMoriya interaction(DMI)

Multiscale spatiotemporal meteorological drought prediction:A deep learning approach

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Advances in Climate Change Research 2024年第2期15卷 211-221页

作者： Jia-Li zhang Xiao-Meng HUANG yu-ze SUN Department of Earth System Science Ministry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China

Reliable monitoring and thorough spatiotemporal prediction of meteorological drought are crucial for early warning and decision-making regarding drought-related *** utilisation of multiscale methods is effective for a comprehensive evaluation of drought occurrence and progression,given the complex nature of meteorological ***,the nonlinear spatiotemporal features of meteorological droughts,influenced by various climatological,physical and environmental factors,pose significant challenges to integrated prediction that considers multiple indicators and time *** address these constraints,we introduce an innovative deep learning framework based on the shifted window transformer,designed for executing spatiotemporal prediction of meteorological drought across multiple *** formulate four prediction indicators using the standardized precipitation index and the standard precipitation evaporation index as core methods for drought definition using the ERA5 reanalysis *** indicators span time scales of approximately 30 d and one ***-term indicators capture more anomalous variations,whereas long-term indicators attain comparatively higher accuracy in predicting future *** focus on the East Asian region,notable for its diverse climate conditions and intricate terrains,to validate the model's efficacy in addressing the complexities of nonlinear spatiotemporal *** model's performance is evaluated from diverse spatiotemporal viewpoints,and practical application values are analysed by representative drought *** results substantiate the effectiveness of our proposed model in providing accurate multiscale predictions and capturing the spatiotemporal evolution characteristics of *** of the four drought indicators accurately delineates specific facets of the meteorological drought ***,three representative drought events,namely flash drought,sustained drought and severe drought,

关键词： Meteorological drought Spatiotemporal prediction Multiscale Swim transformer Deep learning

Centroid Hom-associative Algebras and Centroid Hom-Lie Algebras

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Acta Mathematica Sinica,English Series 2024年第4期40卷 935-961页

作者： yu Xiu BAI Leonid A.BOKUT yu Qun CHEN ze Rui zhang Department of Mathematics Teaching Guangzhou Civil Aviation CollegeGuangzhou 510403P.R.China Sobolev Institute of Mathematics Novosibirsk 630090Russia Novosibirsk State University Novosibirsk 630090Russia School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this article,we construct free centroid hom-associative algebras and free centroid hom-Lie *** also construct some other relatively free centroid hom-associative algebras by applying the Gr?bner-Shirshov basis theory for(unital)centroid hom-associative ***,we prove that the"Poincaré-Birkhoff-Witt theorem"holds for certain type of centroid hom-Lie algebras over a field of characteristic 0,namely,every centroid hom-Lie algebra such that the eigenvectors of the mapβlinearly generates the whole algebra can be embedded into its universal enveloping centroid hom-associative algebra,and the linear basis of the universal enveloping algebra does not depend on the multiplication table of the centroid hom-Lie algebra under consideration.

关键词： Centroid hom-Lie algebra centroid hom-associative algebra Gr?bner-Shirshov basis

Solar evaporation for simultaneous oil-water separation and electricity generation with Janus wood-based absorbers

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 13-23页

作者： yue Yang ze Fu Qi zhang Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science&TechnologyNanjing 210094China Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresCollege of Engineering and Applied SciencesKey Laboratory of Intelligent Optical Sensing and Manipulation(Ministry of Education)Jiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210093China

Oily wastewater from ocean oil spills endangers marine ecosystems and human health. Therefore, developing an effective and sustainable solution for separating oil-water mixtures is urgent. Interfacial solar photothermal evaporation is a promising approach for the complete separation of two-phase mixtures using only solar energy. Herein, we report a carbonized wood-based absorber with Janus structure of comprising a hydrophobic top-layer and an oleophobic bottom-layer for simultaneous solar-driven oil-water separation and electricity generation. Under sunlight irradiation, the rapid evaporation of seawater will induce a separation of oil-water mixtures, and cause a high salt concentration region underlying the interface, while the bottom “bulk water” maintains in a low salt concentration, thus forming a salinity gradient. Electricity can be generated by salinity gradient power. Therefore, oil-water separation efficiency of > 99% and derived extra electricity power of ~0.1 W/m2 is achieved under solar radiation, demonstrating the feasibility of oil-water separation and electricity production synchronously directly using solar energy. This work provides a green and cost-effective path for the separation of oil-water mixtures.

关键词： Oily wastewater Carbonized wood Salinity gradient Electricity generation Solar irradiation