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Study on the flow structure in curved open channels with suspended vegetation using multi relaxation time lattice Boltzmann method

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Journal of Hydrodynamics 2024年第2期36卷 300-315页

作者： he-fang Jing Qiao-ling Zhang wei-hong Wang Zong-ning Zhang School of Mathematics and Information Science North Minzu UniversityYinchuan750021China School of Civil Engineering North Minzu UniversityYinchuan750021China Department of Basic Courses Zhengzhou University of Science and TechnologyZhengzhou450064China

Suspended vegetation in rivers,lakes,reservoirs and canals can change flow structure,which will in turn affect the sediment transport and cause the variation of water ecological *** order to study the characteristics of bend flow through suspended vegetation,three-dimensional numerical simulations are carried out by using the multi-relaxation-time lattice Boltzmann method(MRT-LBM).The drag force induced by vegetation is added in the velocity correction in the equilibrium distribution and a hybrid format combined bounce and specular reflection scheme is applied in the solid-fluid *** the validation of this model,six cases are designed to conduct the numerical simulations according to the root depth and the arrangement of *** simulated results show that the suspended vegetation can redistribute the flow structure in curved open *** the arrangement of suspended vegetation,the main flow moves to the side without vegetation,and the distribution of velocity tends to be balanced when vegetation is arranged on the entire cross section,the range of circulating current is reduced from the whole cross section to the local position without vegetation,however,the circulating current can still exist in the curve where the suspended vegetation enters less than half of the water *** addition,it can also be concluded that the suspended vegetation can affect the lateral gradient of flow velocity,and the bed shear stress in the curved channel.

关键词： Multi-relaxation-time lattice Boltzmann method(MRT-LBM) suspended vegetation curved open channel circulating current bed shearstress

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

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Rare Metals 2024年第6期43卷 2832-2841页

作者： Yan Jiang Liang-Liang wei Jian he hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2)O_(3) Superalloy

Ultrasound blood flow characteristics changes in fetal umbilical artery thrombosis:A retrospective analysis

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World Journal of Clinical Cases 2024年第2期12卷 240-248页

作者： Si-Jie hong Li-wei hong Xiao-Qin he Xiao-hong Zhong Department of Ultrasound Women and Children's HospitalSchool of MedicineXiamen UniversityXiamen 361000Fujian ProvinceChina Ministry of Science and Education Women and Children's HospitalSchool of MedicineXiamen UniversityXiamen 361000Fujian ProvinceChina

BACKGROUND Umbilical artery thrombosis(UAT)is extremely uncommon and leads to adverse perinatal *** of blood in pregnant women is suspected to be an important risk for *** is an effective way to detect *** mother can monitor her own fetal health using ultrasound,which enables her to take preventative action in case of *** To investigate ultrasonic blood signal after UAT in the umbilical artery,and evaluate the relationship between hypercoagulability and *** We described a case of a newly formed UAT with markedly altered ultrasonic indices of umbilical artery blood flow,and retrospectively studied it with 18 UAT patients confirmed by histopathology from October 2019 and March 2023 in Xiamen Women and Children's ***’information was collected from medical archives,including maternal clinical data,neonatal outcomes,pathological findings and ultrasonic indices of umbilical artery blood flow,such as systolic-diastolic duration ratio(S/D),resistance index(RI),pulsatility index(PI)and peak systolic velocity(PSV).Ultrasound and coagulation indices were analyzed with matched samples t-test and Wilcoxon rank sum test using the statistical packages in R(version 4.2.1)including car(version 3.1-0)and stats(version 4.2.1),and visualized by ggplot2 package(version 3.3.6).RESULTS A patient with normal findings in second and third-trimester routine ultrasound scan developed UAT with severe changes in ultrasonic indices of umbilical artery blood flow(within 2.5th of reference ranges)in a short period of *** analysis of umbilical artery blood flow ultrasound indices for 19 patients with UAT showed that the decrease in S/D,RI,and PI and increase of PSV during the disease process was greater than that of *** 18 patients delivered in our hospital showed characteristic manifestations of UAT on histological examination after delivery,most of which(16/18)showed umbilical cord abnormalities,with 1

关键词： Umbilical artery thrombosis Obstetric ultrasonography Peak systolic velocity Hypercoagulation Umbilical cord abnormalities Fetus

Low Surface Brightness Galaxies Selected by Different Model Fitting

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Research in Astronomy and Astrophysics 2024年第1期24卷 223-236页

作者： Bing-Qing Zhang hong Wu wei Du Pin-Song Zhao Min he Feng-Jie Lei Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We present a study of low surface brightness galaxies(LSBGs) selected by fitting the images for all the galaxies inα.40 SDSS DR7 sample with two kinds of single-component models and two kinds of two-component models(disk+bulge):single exponential,single sersic,exponential+deVaucular(exp+deV),and exponential+sérsic(exp+ser).Under the criteria of the B band disk central surface brightness μ_(0,disk)(B)≥22.5 mag arcsec^(-2) and the axis ratio b/a> 0.3,we selected four none-edge-on LSBG samples from each of the models which contain 1105,1038,207,and 75 galaxies,*** are 756 galaxies in common between LSBGs selected by exponential and sersic models,corresponding to 68.42% of LSBGs selected by the exponential model and 72.83% of LSBGs selected by the sersic model,the rest of the discrepancy is due to the difference in obtaining μ_(0) between the exponential and sersic *** on the fitting,in the range of 0.5≤n≤1.5,the relation of μ_(0) from two models can be written as μ_(0,sérsic)-μ_(0,exp)=-1.34(n-1).The LSBGs selected by disk+bulge models(LSBG_(2)comps) are more massive than LSBGs selected by single-component models(LSBG_1comp),and also show a larger disk *** the bulges in the majority of our LSBG_(2)comps are not prominent,more than 60% of our LSBG_(2)comps will not be selected if we adopt a single-component model *** also identified 31 giant low surface brightness galaxies(gLSBGs) from LSBG_(2)*** are located at the same region in the color-magnitude diagram as other *** we compared different criteria of gLSBGs selection,we find that for gas-rich LSBGs,M_(*)> 10^(10)M_⊙ is the best to distinguish between gLSBGs and normal LSBGs with bulge.

关键词： catalogs galaxies:spiral galaxies:bulges methods:data analysis methods:statistical

High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： wei-Zhi Luo Mu he Liang Xia Qi-Chang he State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et Simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

Nutrient transport following water transfer through the world's largest water diversion channel

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Journal of Environmental Sciences 2024年第1期135卷 703-714页

作者： Yuanhui Cheng hong Zhang wei Yin State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085 China Changjiang Water Resources Protection Institute Wuhan 430051China University of Chinese Academy of Sciences Beijing 100049China

Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin ***,the distribution and transport of nutrients along the channel were poorly *** on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this *** results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main *** temperature difference was the major factor in the large fluctuations of water quality indicators over *** nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving *** deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,*** 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main *** increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main *** study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.

关键词： Nutrient transport Spatiotemporal patterns The Middle Route The South-to-North Diversion Project Hydro-ecological effects Water-receiving cities

Hydrodynamic characteristics and particle tracking of 90° lateral intakes at an inclined river slope

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Water Science and Engineering 2024年第2期17卷 197-208页

作者： wei he Si-yuan Feng Jian Zhang hong-wu Tang Yang Xiao Sheng Chen Chun-sheng Liu College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Collaborative Innovation Center on Water Safety and Water Science Hohai UniversityNanjing 210098China

Lateral intakes are common in *** pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division *** hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be ***,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be ***,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side *** flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel *** study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this *** average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank *** a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical *** inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope *** results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.

关键词： Lateral withdrawal Hydrodynamic characteristics Particle tracking Inclined river slope Bottom elevation of intake OpenFOAM

Microstructural evolution,mechanical properties and degradation mechanism of PS-PVD quasi-columnar thermal barrier coatings exposed to glassy CMAS deposits

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Rare Metals 2024年第7期43卷 3329-3340页

作者： Zi-Yue Yu Liang-Liang wei Xing-Ye Guo Bao-Peng Zhang Qing he hong-Bo Guo School of Materials Science and Engineering Beihang University Key Laboratory of High-Temperature Structure Materials and Protective Coatings (Ministry of Industry and Information Technology) Beihang University Surface Engineering Research Institute Chinese Academy of Agricultural Mechanization Sciences

Thermal barrier coatings（TBCs） applied in aeroengines tend to be attacked by molten calcia-magnesiaalumino-silicate（CMAS） at high operating ***-stabilized zirconia（YSZ） coatings with quasicolumnar microstructure were fabricated by plasma spray physical vapor deposition（PS-PVD） *** chemic al changes,micros tructural transform ation,mechanical properties and degradation mechanisms of the CM AS-interacted TBCs in the thermal cycling tests were *** YSZ grains were dissolved in the CMAS melts,and then the ZrO2grains were reprecipitated with spherical shape,accompanying with phase transformation from tetragonal（t） to monoclinic（m）.The thermal cycling tests reveal that the YSZ coating fails at the early stage due to the attack of *** fractures in intracolumns lead to partial spallation of the *** failure of the coating occurs at the interfaces between thermally grown oxides（TGO） layer and YSZ topcoat;especially,the hardness and Young's modulus of the YSZ coatings increase intensively,as the coatings were infiltrated by the CMAS for a long time.

关键词： CMAS Thermal barrier coatings Young’s modulus Thermal cycling behavior PS-PVD

Malvidin Mitigates Sepsis-induced Cardiac Injury by Modulating the TLR4-iNOS-COX-2 Inflammatory Pathway and the Bax/Bcl-2/Cyto-C Mitochondrial Apoptosis Pathway in a p38 MAPK-dependent Manner

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Biomedical and Environmental Sciences 2024年第2期37卷 221-227页

作者： ZHANG wei YUAN Si Long QIANG Jing Chao HUANG he LI Da SUN Ying ZHANG hong Gang Department of Vascular Surgery The First People’s Hospital of LianyungangLianyungang 222005JiangsuChina Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening College of PharmacyJiangsu Ocean UniversityLianyungang 222005JiangsuChina Jinzhou Medical University postgraduate training base(Lianyungang First People’s Hospital) Lianyungang 222005JiangsuChina

In critical care medicine,sepsis is a dangerous systemic condition that is highly prevalent and is associated with high morbidity and mortality rates^([1]).The high mortality rate associated with sepsis is closely related to multi-organ dysfunction,with heart injury being particularly critical and considered the starting point of multi-organ injury^([2]).

关键词： mortality Apoptosis TLR4