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透水丁坝对不同曲率弯道内三维水流结构影响数值模拟研究

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中国农村水利水电 2024年第5期 31-40页

作者：谢鹏李春光吕岁菊景何仿张凤逐宁夏大学土木与水利工程学院宁夏银川750021 北方民族大学数学与信息科学学院宁夏银川750021 北方民族大学土木工程学院宁夏银川750021

透水丁坝相较于传统丁坝,具有更加卓越的稳定性,安全性,可靠性,因此在绿色航道推广中得到重视,研究的目的在于对比不同曲率河道内三维水流结构变化,进而为不同曲率河道治理提供依据。研究采用数值模拟与实测相结合的方式,对3种湍流模型... 详细信息

透水丁坝相较于传统丁坝,具有更加卓越的稳定性,安全性,可靠性,因此在绿色航道推广中得到重视,研究的目的在于对比不同曲率河道内三维水流结构变化,进而为不同曲率河道治理提供依据。研究采用数值模拟与实测相结合的方式,对3种湍流模型进行比选和验证,Standard k-ε,RNG k-ε,Realizable k-ε三种湍流模型内岸模拟流速和实测流速相关性系数均低于外岸,RNG k-ε湍流模型实测流速和模拟流速相关性系数最高,最终采用RNG k-ε模型对90°和180°弯道模拟,并对三维流线,流速,床面剪切,水面线分析。结果显示丁坝下游回流区涡轴线受垂向和径向速度梯度影响出现不同程度倾斜,水流撞击2号丁坝在丁坝之间产生两个相反方向的涡,这将对透水丁坝群结构稳定形成威胁但同时也会防止大量泥沙在透水丁坝之间淤积,保证透水丁坝在使用过程中不至于丧失透水性。河道曲率增大导致强剪切层向内岸迁移,180°弯道内出现两个强剪切层,这将导致河床向阶梯型演化,对于曲率大而且狭窄的山区河道在布置透水丁坝后要对内岸侵蚀效果评估,防止强剪切层迁移对内岸构成威胁。水面线呈现内低外高的现象,且在x/L=0.48~0.5的范围里内外岸水面线差值最小,水面出现凹陷。

关键词：数值模拟河道曲率透水丁坝三维流线床面剪切水面线

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Flow characteristics in curved open channel with partial suspended vegetation

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Journal of Mountain Science 2022年第9期19卷 2715-2728页

作者： ZHANG Qiao-ling jing he-fang LI Chun-guang WANG Wei-hong ZHANG Wen-sheng School of Mathematics and Information Science North Minzu UniversityYinchuan 750021China School of Civil Engineering North Minzu UniversityYinchuan 750021China

Suspended vegetation in open channels such as natural river,lake,reservoir usually affect the flow structure,causing the change of the water environment,sediment transport,bed *** order to study the water flow behavior in curved open channels under the influence of suspended vegetation,experiments were conducted in a Ushaped flume with 180°bend where the suspended vegetation substituted by cylindrical glass rods were partially *** particle image velocimeter(PIV)system was employed to measure the flow velocities of various cases with different vegetation arrangements and roots *** and analysis were conducted for measured data,such as water level,velocity,head loss,Reynolds stress,and turbulence kinetic energy(TKE)to obtain certain general rules of water flow in open curved channels with suspended *** can be found from the measured data that the water level and the head loss in the vegetation area are closely related to the arrangements of the suspended ***,the drag force of the vegetation can not only lead to smaller increments of longitudinal TKE above the vegetation tail than that below it,but also lead to the flow velocities in vegetation area much smaller than areas without *** addition,suspended vegetation weakens the vortex strength near the water surface and increases the vortex strength below the vegetation tail,and the flow velocity in the vegetation area has a close relationship with the suspended vegetation length in the ***,it can be concluded that the reasonable arrangements of suspended vegetation group in curved open channel can protect the concave bank from being scoured,and protect the convex bank from being deposited.

关键词： Curved open channel PIV Suspended vegetation Vegetation arrangements Turbulence kinetic energy

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

Low-thermal-budget synthesis of monolayer MoS2

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Science China Materials 2024年第1期67卷 372-374页

作者： Zongmeng Yang Shibo fang jing Lu State Key Laboratory for Mesoscopic Physics and School of Physics Peking University Collaborative Innovation Center of Quantum Matter Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKL-MEMD) Peking University Peking University Yangtze Delta Institute of Optoelectronics Key Laboratory for the Physics and Chemistry of Nanodevices Peking University Beijing Key Laboratory of Quantum Devices Peking University

Two-dimensional (2D) materials, such as MoS2, have been considered as a competitive coordinate for future electronics due to their excellent electrostatics and high mobility [1–3]. Moreover, the potential integration of 2D materials with silicon circuits can present increased density and multifunction in future heterogeneously integrated circuits [4,5]. However, the high thermal-budget during Mo S2 synthesis exceeds the temperature requirement of direct integration with Si in the back-end-of-line (BEOL) fabrication process [6–8].

关键词： FILMS

Regulation of insect behavior by non-coding RNAs

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Science China(Life Sciences) 2024年第6期67卷 1106-1118页

作者： jing he Le Kang State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China Beijing Institutes of Life Sciences Chinese Academy of SciencesBeijing 100101China College of Life Science Hebei UniversityBaoding 071002China

The adaptation of insects to environments relies on a sophisticated set of behaviors controlled by molecular and physiological *** the past several decades,accumulating studies have unveiled the roles of non-coding RNAs(nc RNAs)in regulating insect *** RNAs assume particularly pivotal roles in the behavioral plasticity of insects by rapidly responding to environmental *** RNAs also contribute to the maintenance of homeostasis of insects by fine-tuning the expression of target ***,a comprehensive review of nc RNAs'roles in regulating insect behaviors has yet to be ***,we present the recent progress in our understanding of how nc RNAs regulate various insect behaviors,including flight and movement,social behavior,reproduction,learning and memory,and *** refine the intricate mechanisms by which nc RNAs modulate the function of neural,motor,reproductive,and other physiological systems,as well as gene expression in insects like fruit flies,social insects,locusts,and ***,we discuss potential avenues for future studies in nc RNA-mediated insect behaviors.

关键词： ncRNAs insect behavior plasticity fine-tuning environmental adaptation

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Repressing iron overload ameliorates central poststroke pain via the Hdac2-Kv1.2 axis in a rat model of hemorrhagic stroke

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Neural Regeneration Research 2024年第12期19卷 2708-2722页

作者： he fang Mengjie Li jingchen Yang Shunping Ma Li Zhang Hongqi Yang Qiongyan Tang jing Cao Weimin Yang Department of Neurology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan ProvinceChina Department of Molecular Neuropathology Beijing Neurosurgical InstituteCapital Medical UniversityBeijingChina Department of Nutrition The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan ProvinceChina Department of Neurology Henan Provincial People’s HospitalZhengzhouHenan ProvinceChina Department of Human Anatomy School of Basic Medical SciencesZhengzhou UniversityZhengzhouHenan ProvinceChina Neuroscience Research Institute Zhengzhou University Academy of Medical SciencesZhengzhouHenan ProvinceChina

Thalamic hemorrhage can lead to the development of central post-stroke *** in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic ***,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea ***,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus *** this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central ***,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain ***,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain *** results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.

关键词： central post-stroke pain hemorrhagic stroke histone deacetylase iron overload voltage-gated potassium ion channel 1.2

Lorentz violation induces isospectrality breaking in Einstein-bumblebee gravity theory

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 87-96页

作者： Wentao Liu Xiongjun fang Jiliang jing Jieci Wang Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

In this study,we investigate the quasinormal modes(QNMs)of a Lorentz-violating spacetime,factoring in a cosmological constant,within the framework of Einstein-bumblebee *** findings reveal that the interaction of spacetime with an anisotropic bumblebee field imparts distinct contributions to the axial and polar sectors of the vector *** subsequently breaks the isospectrality typically observed in vector *** evidence strongly indicates isospectral breaking in the vector modes of Einstein-bumblebee black holes:a pronounced breakage in the real part of the frequencies,while the imaginary component seems less *** isospectral breaking indicates the existence of two different waveforms in the Ringdown phase of the black hole,which provides a potential signal of quantum gravity observable in current experiments.

关键词： Lorentz-violating isospectral breaking quasinormal modes

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pH Induced Self-assembly of AIE Fluorescent Probe for Tumor Imaging

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Chinese Journal of Polymer Science 2024年第1期42卷 7-13,I0005页

作者： jing-Yuan Xiang Wen-Long Zhang he-Ting Li Ya-Ning he Department of Chemical Engineering Key Laboratory of Advanced Materials(MOE)Tsinghua UniversityBejing 100084China

This work reported an AIE fluorescent probe for tumor imaging based on the p H induced self-assembly strategy. The fluorescent probe was composed of an acid-responsive soluble copolymer PEG-b-PAMA-DMMA with a maleic acid amide group and an anionic soluble aggregation-induced emission fluorogen(AIEgen) TPE-2SO_(3)^(-). The polymer could be transformed into a protonated amine-containing polymer after the hydrolysis of maleic acid amide in acidic tumor microenvironment, which would be further self-assembled with TPE-2SO_(3)^(-)to form aggregated nanoparticles. The transition of TPE-2SO_(3)^(-)from dispersed state to aggregated state led to an obvious increase in fluorescence intensity due to its AIE characteristics.

关键词： p H-responsive Self-assembly Fluorescent probe AIE Tumor imaging

From common biomass materials to high-performance tissue engineering scaffold: Biomimetic preparation, properties characterization, in vitro and in vivo evaluations

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Journal of Bioresources and Bioproducts 2024年第2期9卷 185-196页

作者： Zongpu Xu fang he jing Yu Zhangze Yang Yu Zhu Rong Liao Ruyin Lyu Mei Yang Liangjun Zhu Mingying Yang Institute of Applied Bioresources College of Animal SciencesZhejiang UniversityHangzhou 310058China Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province Zhejiang UniversityHangzhou 310058China Department of Neurosurgery the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Converting common biomass materials to high-performance biomedical products could not only reduce the environmental pressure associated with the large-scale use of synthetic materials,but also increase the economic *** as a very promising candidate has drawn considerable attention owing to its abundant sources and remarkable ***,pure chitosan materials usually exhibit insufficient mechanical properties and excessive swelling ratio,which seriously affected their in vivo stability and integrity when applied as tissue engineering ***,simultaneously improving the mechanical strength and biological compatibility of pure chitosan(CS)scaffolds becomes very ***,inspired by the fiber-reinforced con-struction of natural extracellular matrix and the porous structure of cancellous bone,we built silk microfibers/chitosan composite scaffolds via ice-templating *** biomimetic strategy achieved 500%of mechanical improvement to pure chitosan,and meanwhile still maintaining high porosity(>87%).In addition,the increased roughness of chitosan pore walls by embedded silk microfibers significantly promoted cell adhesion and *** importantly,after subcutaneous implantation in mice for four weeks,the composite scaffold showed greater struc-tural integrity,as well as better collagenation,angiogenesis,and osteogenesis abilities,suggesting its great potential in biomedicine.

关键词： Chitosan Biomimetic strategy Fiber-reinforced composite Mechanical property Biocompatibility