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Numerical study of submerged bending vegetation under unidirectional flow

Water Science and Engineering 2024年第1期17卷 92-100页

作者： pei-pei Zhang Yi-qing Gong Ken Vui Chua Jie Dai Jing-qiao mao College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Institute of Water Science and Technology Hohai UniversityNanjing 210098China School of Engineering Cardiff UniversityCardiff CF243AAUK

Submerged vegetation commonly grows and plays a vital role in aquatic ecosystems,but it is also regarded as a barrier to the passing flow.Numerical simulations of flow through and over submerged vegetation were carried out to investigate the effect of vegetation density on flow field.Numerical simulations were computationally set up to replicate flume experiments,in which vegetation was mimicked with flexible plastic strips.The fluid-structure interaction between flow and flexible vegetation was solved by coupling the two modules of the COMSOL packages.Two cases with different vegetation densities were simulated,and the results were successfully validated against the experimental data.The contours of the simulated time-averaged streamwise velocity and Reynolds stress were extracted to highlight the differences in mean and turbulent flow statistics.The turbulence intensity was found to be more sensitive to vegetation density than the time-averaged velocity.The developing length increased with the spacing between plants.The snapshots of the bending vegetation under instantaneous velocity and vorticity revealed that flexible vegetation responded to the effects of eddies in the shear layer by swaying periodically.The first two rows of vegetation suffered stronger approaching flow and were prone to more streamlined postures.In addition,the origin of tip vortices was investigated via the distribution of vorticity.The results reveal the variation of flow properties with bending submerged vegetation and provide useful reference for optimizationofrestorationprojects.

关键词： Computational fluid dynamics Fluid-structure interaction Turbulence Flexible and submerged vegetation

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Phylogenetic analysis and target gene prediction of miR477 gene family in grape

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BIOCELL 2022年第4期46卷 941-949页

作者： HUI-YING JIN mao-SONG pei DA-LONG GUO College of Horticulture and Plant Protection Henan University of Science and TechnologyLuoyang471023China Henan Engineering Technology Research Center of Quality Regulation of Horticultural Plants Luoyang471023China

To understand the molecular characteristics of the miR477 gene family of grape(Vvi-miR477)and to predict its target genes,the Vvi-miR477 genes were identified from previous small RNA sequencing data,then phylogenetic analysis and prediction of target gene were conducted.The Vvi-miR477 family consists of two precursor sequences and three mature sequences.The miR477 family members were mostly 19-22nt in length.The sequence is relatively conservative.Vvi-MIR477a and Vvi-MIR477b are located on chromosomes 1 and 2,respectively.These precursor sequences can form the typical stable stem-loop structure.Their minimum folding free energy is−39.10 kcal/mol and−50.90 kcal/mol,respectively.The MIR477 family can be divided into three groups.The prediction of target genes showed that Vvi-miR477 targets 26S proteasome,DEAD-box,GRAS family protein,Protein Phosphatase 2C,etc.The GO function of target genes was mainly enriched to six categories.The catabolic process,carboxylic ester hydrolase activity is shown to be high.This study provided a theoretical basis for further exploration of the molecular mechanism of miR477 in grape berry ripening.

关键词： Vitis vinifera miRNA Fruit ripening Phylogenetic characteristics Target genes

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More children nutrition distribution, less labor incentive: Evidence from Chinese collective agriculture

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Journal of Integrative Agriculture 2019年第10期18卷 2422-2433页

作者： HUANG Ying-wei MAO Pei LI Jun Institute of Economics Chinese Academy of Social SciencesBeijing 100836P.R. China College of Economics Central University of Finance and EconomicsBeijing 100081P.R.China College of Economics and Management China Agricultural UniversityBeijing 100094P.R. China

Distribution system will affect the labor incentive that has been heatedly discussed by recent literatures.Using a unique micro dataset, this paper dem on strates that the equalitaria n distributi on system is one of the reas ons for the in sufficie nt labor incentive during the Chinese Collective Agriculture period. Specifically speaking, in the distribution of basic rations, the proportion for children (aged 1-3 and 4-7 years) was often beyond their nutrition demand, resulting the dissatisfaction of other families with more laborers and less children, thus these households will reduce their labor supply gradually. At the same time, the existence of outstanding accounts makes it a failure to use work points to buy distributions, which is the mechanism of the distribution system and insufficient labor incentive. All the results have been accepted by the robustness tests. The study will help to understand the distribution system and labor incentive, as well as the failure of the Chinese collective agriculture.

关键词： ratio of children's nutrition distribution labor incentive outstanding accounts Chinese collective agriculture

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Numerical simulation on recrystallization behavior and microstructure evolution during hot continuous rolling process of 38CrMoAl steel rod

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Journal of Iron and Steel Research(International) 2022年第10期29卷 1633-1645页

作者： Fei Li Li-wen Zhang Chi Zhang Kang-jie Song pei-gang mao School of Materials Science and Engineering Dalian University of TechnologyDalian116024LiaoningChina

The control of microstructure during hot rolling process of steel is of great importance and will affect the properties of the steel products.According to the production line,a three-dimensional multi-field coupled finite element model of 24-pass continuous hot rolling process of 38CrMoAl steel rod is established using the finite element software MSC.Marc.Based on the recrystallization kinetics model and the grain growth model,a subroutine written in Fortran is introduced to calculate the recrystallization behavior and microstructure evolution of 38CrMoAl steel during the entire rolling process.The distribution and evolution of variables such as strain,temperature and recrystallization fractions during the rolling process are analyzed.The temperature variations and grain sizes at both the center and surface of the tested steel are compared with the experimental results.And it is found that the simulation results are in good agreement with the experimental ones,confirming the reliability of the established model.

关键词： 38CrMoAl steel Recrystallization Microstructure evolution Hot rolling process Numerical simulation

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Laser patterning of large-scale perovskite single-crystal-based arrays for single-mode laser displays

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International Journal of Extreme Manufacturing 2023年第4期5卷 462-470页

作者： Wangqi mao Haonan Li Bing Tang Chi Zhang Liang Liu pei Wang Hongxing Dong Long Zhang Department of Optics and Optical Engineering University of Science and Technology of ChinaHefeiAnhui 230026People’s Republic of China Key Laboratory of Materials for High-Power Laser Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800People’s Republic of China Department of Materials Science and Engineering and Centre for Functional Photonics(CFP)City University of Hong KongHong Kong Special Administrative Region of China 999077People’s Republic of China School of Physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouZhejiang 310024People’s Republic of China Key Laboratory for Micro/Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Materials Science and EngineeringHunan UniversityChangsha 410082People’s Republic of China

Lead halide perovskites have attracted considerable attention as potential candidates for high-performance nano/microlasers,owing to their outstanding optical properties.However,the further development of perovskite microlaser arrays(especially based on polycrystalline thin films)produced by the conventional processing techniques is hindered by the chemical instability and surface roughness of the perovskite structures.Herein,we demonstrate a laser patterning of large-scale,highly crystalline perovskite single-crystal films to fabricate reproducible perovskite single-crystal-based microlaser arrays.Perovskite thin films were directly ablated by femtosecond-laser in multiple low-power cycles at a minimum machining line width of approximately 300 nm to realize high-precision,chemically clean,and repeatable fabrication of microdisk arrays.The surface impurities generated during the process can be washed away to avoid external optical loss due to the robustness of the single-crystal film.Moreover,the high-quality,large-sized perovskite single-crystal films can significantly improve the quality of microcavities,thereby realizing a perovskite microdisk laser with narrow linewidth(0.09 nm)and low threshold(5.1µJ/cm2).Benefiting from the novel laser patterning method and the large-sized perovskite single-crystal films,a high power and high color purity laser display with single-mode microlasers as pixels was successfully fabricated.Thus,this study may offer a potential platform for mass-scale and reproducible fabrication of microlaser arrays,and further facilitate the development of highly integrated applications based on perovskite materials.

关键词： perovskite single-crystal film single-mode microlaser femtosecond-laser processing laser display Supplementary material for this article is available online

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Hydrothermal ore deposits in collisional orogens

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Science Bulletin 2019年第3期64卷 205-212页

作者： Yongfei Zheng Jingwen mao Yanjing Chen Weidong Sun pei Ni Xiaoyong Yang Key Laboratory of Crust-Mantle Materials and Environments Chinese Academy of Sciences School of Earth and Space Sciences University of Science and Technology of China Key Laboratory of Metallogeny and Mineral Assessment Ministry of Natural Rescources Institute of Mineral Resources Chinese Academy of Geological Sciences Key Laboratory of Orogen and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Key Laboratory of Marine Geology and Environment Center of Deep-Sea Research Institute of Oceanology Chinese Academy of Sciences State Key Laboratory for Mineral Deposits Research Institute of Geo-Fluids School of Earth Sciences and Engineering Nanjing University

Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.

关键词： Ore deposits Hydrothermal fluid Accretionary orogen Collisional orogen Rifting orogen Tectonic reactivation

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Axial flow structure of solids holdup in an 18-m high-density CFB riser based on pressure measurements

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Particuology 2021年第1期19卷 116-125页

作者： Xin Su Chengxiu Wang Xingying Lan Huajian pei Xiaoyang mao Jinsen Gao State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China

The axial flow structure in a high-density CFB riser having a height of 18 m is investigated on the basis of pressure measurements.Solids circulation rates reach 1400 kg/(m2 s)at superficial gas velocities of 5-9 m/s and the apparent solids holdup exceeds 0.2,indicating high-density operations have been achieved.The apparent solids holdup increases with the solids circulation rate increasing and/or superficial gas velocity decreasing.Axial distributions of the apparent solids holdup have exponential shapes with denser regions at the bottom and more dilute regions in the upper part.The apparent slip velocity increases with the increasing solids holdup and reaches 14 m/s,showing that there are more opportunities of cluster formation in high-density operation.Furthermore,the apparent slip velocity has a power relation with the apparent solids holdup under a wide range of operating conditions.

关键词： Circulating fluidized bed Pressure measurement Flow structure Solids holdup Slip velocity

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Effects of Perinatal Complications on Coagulation Function in Pregnant Women

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Reproductive and Developmental Medicine 2019年第1期3卷 60-62页

作者： Wei-Qin Yu Xiao-Yan Liu pei-Min mao Department of Blood Transfusion Obstetrics and Gynecology Hospital of Fudan UniversityShanghai 200090China

Objectives:To investigate the effects of various complications on the coagulation function of perinatal women.Methods:A total of 210 pregnant women between November 2016 and June 2017 were recruited.The coagulation function indexes,including prothrombin time(PT),activated partial thromboplastin time(APTT),fibrinogen(FIB),and thrombin time(TT),were evaluated in pregnant women with group B Streptococcus(GBS),positive nonstress test(NST),scarred uterus,prenatal fever,macrosomia,gestational hypertension,gestational diabetes,premature rupture of membranes(PROMs),threatened abortion,and oligohydramnios.Results:No significant differences were found in PT,APTT,FIB,and TT in pregnant women with GBS,positive NST,scarred uterus,macrosomia,gestational hypertension,gestational diabetes,PROMs,and oligohydramnios.Moreover,significantly decreased PT and APTT and significantly increased TT were found in pregnant women with prenatal fever compared to normal controls,whereas significantly increased TT was also observed in those with threatened abortion.Conclusions:Among the complications that occur in pregnant women,prenatal fever and threatened abortion have important effects on coagulation function.

关键词： Coagulation Complication Perinatal Period Pregnancy Prenatal Fever Threatened Abortion

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A regeneration system using cotyledons and cotyledonary node explants of Toona ciliata

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Journal of Forestry Research 2021年第3期32卷 967-974页

作者： Huiyun Song Wenmai mao Yuanyuan Shang Wei Zhou pei Li Xiaoyang Chen Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm Guangzhou 510642People’s Republic of China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources Guangzhou 510642People’s Republic of China College of Forestry and Landscape Architecture South China Agricultural UniversityGuangzhou 510642People’s Republic of China

We used the cotyledons and cotyledonary nodes of Toona ciliata(Chinese mahogany)as explants to examine callus and adventitious shoot induction when exposed to different ratios of hormones.We also investigated the effects of seedling age,inoculation method,and genotype on the efficient regeneration of T.ciliata.The results showed that different genotypes exhibited significantly different callus induction efficiency.The cotyledons and cotyledonary nodes of 20-day seedlings inoculated onto MS medium with 0.5 mg/L 6-benzylaminopurine(6-BA),0.5 mg/L kinetin(KT)and 0.05 mg/L 1-naphthylacetic acid(NAA)achieved a greater regeneration rate than did other concentrations of cytokinin and auxin.The numbers of shoots per cotyledon and cotyledonary node explant were 7.33 and 6.67.The optimal inoculation method for cotyledons was that the distal end of the explants was placed in contact with the medium.The optimal adventitious shoot differentiation medium for cotyledon explants was MS medium containing 0.3 mg/L 6-BA and 0.2 mg/L NAA,producing a 3.4 cm height of shoot on average.This study established an efficient regeneration system for T.ciliata with cotyledons and cotyledonary nodes as explants.

关键词： Cotyledons Cotyledonary nodes Regeneration system Toona ciliata

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Cryptanalysis of a lattice based key exchange protocol

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Science China(Information Sciences) 2017年第2期60卷 196-198页

作者： Shaowu mao pei ZHANG Houzhen WANG Huanguo ZHANG Wanqing WU Computer School of Wuhan University The Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education Huawei Technoligies Co. Ltd. School of Computer Science and Technology Hebei University

A lattice is a set of points in n-dimensional space with a periodic structure.Lattice-based cryptosystem holds a great promise for post-quantum cryptography[1],as they enjoy very strong security proofs based on the worst-case hardness,relatively efficient implementations,as well as great simplicity.The first lattice-based cryptosystem was proposed by Ajtai and Dwork[2],whose security is based on the lattice problems in the worstcase.After their seminal work,several latticebased cryptosystems have been proposed till now,

关键词： ISIS Bi Cryptanalysis of a lattice based key exchange protocol

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