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Turbulent Modeling of Wall-Bounded Flow with Memory Effects

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Turbulent Modeling of Wall-Bounded Flow with Memory Effects

Cell replacement with stem cell-derived retinal ganglion cells from different protocols

The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-Hong Kong Forum on Mechanics and Its Application 2012

作者： X.Qiu j.p.luo Y.L.Liu School of Science Shanghai Institute of Technology School of Mechanical Engineering Shanghai Institute of Technology Shanghai Institute of Applied Mathematics and Mechanics Shanghai University

Memory effects have been recognized to be very important in turbulent shear *** turbulent flows of Newtonian fluids have already been compared with non-Newtonian laminar flows. In this paper the analogy between these classes of flows is explored,and a new approach to derive a turbulent model concerning memory effects based on a nonlinear constitutive equation is *** order to reach this aim,opened DNS databases of turbulent channel flows are used and analyzed in the light of the classical parameters of non-Newtonian constitutive *** Reynolds stress tensor is expressed in terms of a set of basis tensors based on a projection of a nonlinear *** coefficients of the model are given as functions of the intensity of the mean strain *** apparent turbulent viscosity,the first and second normal stress difference,are presented in function of the shear rate.A turbulent Weissenberg number,based on a characteristic turbulent time ratio of the first normal stress difference to the apparent viscosity is also *** material functions, exhibiting a shear-thinning behavior,are fitted with the power law(the Carreau-type) *** range of the Reynolds number investigated was 180≤Reτ≤*** of the advantages of the new algebraic nonlinear power law constitutive equation derived in the paper is that its dependence is only on the mean velocity gradient and can be integrated up to the wall.

关键词： Turbulent Modeling of Wall-Bounded Flow with Memory Effects

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Neural Regeneration Research 2024年第4期19卷 807-810页

作者： Ziming luo Kun-Che Chang Spencer Center for Vision Research Byers Eye InstituteStanford University School of Medicine Department of Ophthalmology Louis J.Fox Center for Vision RestorationUniversity of Pittsburgh School of Medicine Department of Neurobiology Center of NeuroscienceUniversity of Pittsburgh School of Medicine

Glaucoma,characterized by a degenerative loss of retinal ganglion cells,is the second leading cause of blindness *** is currently no cure for vision loss in glaucoma because retinal ganglion cells do not regenerate and are not replaced after *** stem cell-derived retinal ganglion cell transplant is a potential therapeutic strategy for retinal ganglion cell degenerative *** this review,we first discuss a 2D protocol for retinal ganglion cell differentiation from human stem cell culture,including a rapid protocol that can generate retinal ganglion cells in less than two weeks and focus on their transplantation ***,we discuss using 3D retinal organoids for retinal ganglion cell transplantation,comparing cell suspensions and *** review provides insight into current knowledge on human stem cell-derived retinal ganglion cell differentiation and transplantation,with an impact on the field of regenerative medicine and especially retinal ganglion cell degenerative diseases such as glaucoma and other optic neuropathies.

关键词： cell clumps cell suspension cell transplantation differentiation direct-induced protocol glaucoma optic neuropathy regenerative medicine retinal ganglion cell retinal organoids stem cells

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

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journal of Mountain Science 2024年第1期21卷 146-159页

作者： HAO Aihua luo Zhengming CHEN Xiaojiang Department of Geography Xinzhou Normal UniversityXinzhou 034000China Department of Biological Sciences Xinzhou Normal UniversityXinzhou 034000China

Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(ppercentage of increasing temperature and decreasing moisture both gradually raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(ppppth of 0–10 cm at three elevational gradients. Warming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(pponses to soil temperature and soil moisture in the warmed treatm

关键词： Warming effect plant diversity pattern Community structure change Elevation gradient Alpine meadow ecosystem Mount Wutai

Experimental study on shock interaction control of double wedge in high-enthalpy hypersonic flow subject to plasma synthetic jet

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Chinese journal of Aeronautics 2024年第4期37卷 151-165页

作者： Xuzhen XIE Qiang LIU Yan ZHOU Zhenbing luo Wei XIE Guanghui BAI Kai luo Qiu WANG jianjun WU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China China Academy of Launch Vehicle Technology Beijing 100076China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The hypersonic shock-shock interaction flow field at double-wedge geometries controlled by plasma synthetic jet actuator is experimentally studied in a Ma = 8 high-enthalpy shock tunnel with the purpose of exploring a novel technique for reducing surface heat flux in a real flight environment. The results demonstrate that increasing the discharge energy is advantageous in eliminating the shock wave, shifting the shock wave interaction point, and shortening the control response time. The oblique shock wave can be completely removed when the actuator's discharge energy grows from 0.4 j to 11.5 j, and the displacement of the shock wave interaction point increases by 124.56%, while the controlled response time is shortened by 30 μs. Besides, the reduction in diameter of the jet exit is firstly proved to have a negative impact on energy deposition in a working environment with incoming flow, which reduces the discharge energy and hence decreases the control effect. The shock wave control response time lengthens when the jet exits away from the second wedge. Along with comparing the change in wall heat flux at the second wedge over time, the control effect of plasma synthetic jet actuator with and without inflation is also analyzed. When plasma synthetic jet works in inflatable mode, both the ability to eliminate shock waves and the shifting effect of the shock wave interaction point are increased significantly, and the wall heat flux is also reduced.

关键词： Hypersonic flow High-enthalpy flow plasma synthetic jet Shock wave Flow control

Discrete Boltzmann model with split collision for nonequilibrium reactive flows

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Communications in Theoretical physics 2024年第8期76卷 166-188页

作者： Chuandong Lin Kai H luo Huilin Lai Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen University Key Laboratory for Thermal Science and power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Department of Mechanical Engineering National University of Singapore Department of Mechanical Engineering University College London School of Mathematics and Statistics Key Laboratory of Analytical Mathematics and Applications (Ministry of Education) Fujian Key Laboratory of Analytical Mathematics and Applications (FJKLAMA) Center for Applied Mathematics of Fujian Province (FJNU) Fujian Normal University

A multi-relaxation-time discrete Boltzmann model(DBM) with split collision is proposed for both subsonic and supersonic compressible reacting flows, where chemical reactions take place among various components. The physical model is based on a unified set of discrete Boltzmann equations that describes the evolution of each chemical species with adjustable acceleration, specific heat ratio, and prandtl number. On the right-hand side of discrete Boltzmann equations, the collision,force, and reaction terms denote the change rates of distribution functions due to self-and crosscollisions, external forces, and chemical reactions, respectively. The source terms can be calculated in three ways, among which the matrix inversion method possesses the highest physical accuracy and computational efficiency. Through Chapman–Enskog analysis, it is proved that the DBM is consistent with the reactive Navier–Stokes equations, Fick's law and the Stefan–Maxwell diffusion equation in the hydrodynamic limit. Compared with the one-step-relaxation model, the split collision model offers a detailed and precise description of hydrodynamic, thermodynamic, and chemical nonequilibrium effects. Finally, the model is validated by six benchmarks, including multicomponent diffusion, mixture in the force field, Kelvin–Helmholtz instability, flame at constant pressure, opposing chemical reaction, and steady detonation.

关键词： detonation discrete Boltzmann method nonequilibrium effect reactive flow

Excellent energy storage performance in Bi_(0.5)Na_(0.5)TiO_(3)-based lead-free high-entropy relaxor ferroelectrics via B-site modification

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journal of Advanced Ceramics 2024年第3期13卷 345-353页

作者： Kaihua Yang Gengguang luo Li Ma Ruoxuan Che Zhiyi Che Qin Feng Zhenyong Cen Xiyong Chen jiajun Zhou Nengneng luo State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures School of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China School of Optical and Electronic Information Key Lab of Functional Materials for Electronic Information(B)of Ministry of EducationHuazhong University of Science and TechnologyWuhan 430074China

Next-generation advanced high/pulsed power capacitors urgently require dielectric materials with outstanding energy storage ***_(0.5)Na_(0.5)TiO_(3)-based lead-free materials exhibit high polarization,but the high remanent polarization and large polarization hysteresis limit their applications in dielectric ***,high-entropy perovskite relaxor ferroelectrics(Na_(0.2)Bi_(0.2)Ba_(0.2)Sr_(0.2)Ca_(0.2))(Ti1-x%Zrx%)O_(3)are designed by adding multiple ions in the A-site and replacing the B-site Ti^(4+)with a certain amount of Zr^(4+).The newly designed system showed high relaxor feature and slim polarization-electric(p-E)***,improved relaxor feature and obviously delayed polarization saturation were found with the increasing of Zr^(4+).Of particular importance is that both high recoverable energy storage density of 6.6 j/cm^(3) and energy efficiency of 93.5%were achieved under 550 kV/cm for the ceramics of x=6,accompanying with excellent frequency stability,appreciable thermal stability,and prosperous discharge *** work not only provides potential dielectric materials for energy storage applications,but also offers an effective strategy to obtain dielectric ceramics with ultrahigh comprehensive energy storage performance to meet the demanding requirements of advanced energy storage applications.

关键词： energy storage density (Bi_(0.5)Na_(0.5))TiO_(3) high-entropy perovskite ceramics polarization saturation relaxor ferroelectrics(RFEs)

proteins as nanomagnets and magnetoreceptors

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Zoological Research 2024年第4期45卷 831-832页

作者： p.j.Hore Department of Chemistry University of OxfordUK

It is an appealing notion that a protein molecule could act as a nanomagnet.A genetically encodable biomolecule with a permanent magnetic moment at room temperature could have a range of applications:a magnetogenetic actuator,a magnetic tag for purifying and immobilizing enzymes,a contrast agent for magnetic resonance imaging,and a basis for a biomimetic magnetic sensing device,to name just a few.A magnetic protein could perhaps also function as the sensor in the magnetic compass that enables small songbirds to navigate the huge distances between their breeding and wintering *** though such possibilities may be,how realistic are they?

关键词： magnetic magnets enable

A Novel Tensor Decomposition-Based Efficient Detector for Low-Altitude Aerial Objects With Knowledge Distillation Scheme

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IEEE/CAA journal of Automatica Sinica 2024年第2期11卷 487-501页

作者： Nianyin Zeng Xinyu Li peishu Wu Han Li Xin luo Department of Instrumental and Electrical Engineering Xiamen UniversityXiamen 361005China IEEE College of Computer and Information Science Southwest UniversityChongqing 400715China

Unmanned aerial vehicles(UAVs) have gained significant attention in practical applications, especially the low-altitude aerial(LAA) object detection imposes stringent requirements on recognition accuracy and computational resources. In this paper, the LAA images-oriented tensor decomposition and knowledge distillation-based network(TDKD-Net) is proposed,where the TT-format TD(tensor decomposition) and equalweighted response-based KD(knowledge distillation) methods are designed to minimize redundant parameters while ensuring comparable performance. Moreover, some robust network structures are developed, including the small object detection head and the dual-domain attention mechanism, which enable the model to leverage the learned knowledge from small-scale targets and selectively focus on salient features. Considering the imbalance of bounding box regression samples and the inaccuracy of regression geometric factors, the focal and efficient IoU(intersection of union) loss with optimal transport assignment(F-EIoU-OTA)mechanism is proposed to improve the detection accuracy. The proposed TDKD-Net is comprehensively evaluated through extensive experiments, and the results have demonstrated the effectiveness and superiority of the developed methods in comparison to other advanced detection algorithms, which also present high generalization and strong robustness. As a resource-efficient precise network, the complex detection of small and occluded LAA objects is also well addressed by TDKD-Net, which provides useful insights on handling imbalanced issues and realizing domain adaptation.

关键词： Attention mechanism knowledge distillation(KD) object detection tensor decomposition(TD) unmanned aerial vehicles(UAVs)

Full-spectrum Bi@SrTiO_(3) for bi-directional promotion effects on photocatalytic redox reaction:Insight into intermediates and mechanism

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journal of Rare Earths 2024年第5期42卷 917-929,I0004页

作者： Bin Liu Nanhao Zhou jun Liu Xinglei Wang peter K.j.Robertson Xiaoyuan Chen Chao Chen jianmin luo Chuanyi Wang School of Chemistry and Civil Engineering Shaoguan UniversityShaoguan512005China Chengdu Customs Technology Center Chengdu610041China Key Laboratory of pollutant Chemistry and Environmental Treatment College of Chemistry and Environmental ScienceYili Normal UniversityYining835000China School of Chemistry and Chemical Engineering Queen's University BelfastStranmillis RoadBelfastBT95AGUnited Kingdom Guangzhou Institute of Industrial Intelligence(GIII) Guangzhou511400China

The development of full-spectrum photocatalysts active in the near-infrared(NIR)region has gained increasing attention for deleterious pollutant *** integration of plasmonic metals with semico nductors is an effective way to widen the light re sponse range of photocatalysts due to the strong light absorption and fast plasmonic energy transfer of the localized surface plasmon resonance(LSpR).In this work,the full-spectrum responsive Bi@SrTiO_(3) was prepared via facile solvothermal chemical *** optimal Bi@SrTiO_(3) achieves exceptional photocatalytic Cr(VI)reduction efficiency and tetracycline degradation,realizing bi-directional promotion effects on redox *** to density functional theory(DFT)simulations,the extraordinary photocatalytic performance is attributed to the tunable builtin electric field(IEF)of the Ohmic *** favorable adaptability in real water and high stability of BSTO-25 were proved by experime ntal *** the po ssible photocatalytic mechanism was proposed based on theoretical calculation and experimental ***,the non-toxicity of the BSTO-25 was evaluated by *** cultivation,which further proves the feasibility of treating wastewater with *** work provides a new perspective on constructing full-spectrum-driven photocatalysts for applications dealing with environmental remediation.

关键词： Full-spectrum photocatalysts Localized surface plasmon resonance Ohmic contact Cr(Ⅵ)reduction Antibiotic degradation Rare earths