An incompressible flow solver on a GPU/CPU heterogeneous architecture parallel computing platform

A computational fluid dynamics(CFD)solver for a GPU/CPU heterogeneous architecture parallel computing platform is developed to simulate incompressible flows on billion-level grid points.To solve the Poisson equation,the conjugate gradient method is used as a basic solver,and a Chebyshev method in combination with a Jacobi sub-preconditioner is used as a preconditioner.The developed CFD solver shows good performance on parallel efficiency,which exceeds 90%in the weak-scalability test when the number of grid points allocated to each GPU card is greater than 2083.In the acceleration test,it is found that running a simulation with 10403 grid points on 125 GPU cards accelerates by 203.6x over the same number of CPU cores.The developed solver is then tested in the context of a two-dimensional lid-driven cavity flow and three-dimensional Taylor-Green vortex flow.The results are consistent with previous results in the literature.

Tissue Culture Rapid Propagation and Transplantation Techniques of Anoectochilus roxburghii (Wall) Lind.

[Objectives]To screen the tissue culture rapid propagation formula suitable for each tissue culture stage of Anoectochilus roxburghii( Wall) Lind. [Methods] The stem segments of Fujian A. roxburghii were used as explant to study the tissue culture rapid propagation and transplantation techniques. The comparative experiment was carried out to study the effects of different hormone concentrations on the induction of stem segments,proliferation of cluster buds,rooting and seedling hardening of A. roxburghii,and study the effects of transplantation matrix on the transplantation of A. roxburghii. [Results]MS + 0. 5 mg/L NAA + 2 mg/L BA + 20 g/L sucrose + 6 g/L agar was suitable for induction of stem segments of A. roxburghii; MS + 0. 5 mg/L NAA + 2 mg/L BA + 1 mg/L KT + 25 g/L sucrose + 6 g/L agar was most suitable for proliferation of cluster buds of A. roxburghii; MS + 1. 0 mg/L IBA + 1. 0 mg/L NAA + 1 g/L activated carbon + 50 g/L mashed banana + 25 g/L sucrose + 6 g/L agar was most suitable for rooting and seedling hardening of A. roxburghii; using peat soil: fine sand( 3∶ 1) as transplantation matrix,the survival rate was the highest. [Conclusions] The experiment results are expected to provide references for factory production of A. roxburghii.

Error of large-eddy simulation in the wall pressure fluctuation of a turbulent channel flow

We analyze the error of large-eddy simulation(LES)in wall pressure fluctuation of a turbulent channel flow.To separate different sources of the error,we conduct both direct numerical simulations(DNS)and LES,and apply an explicit filter on DNS data to obtain filtered DNS(FDNS)data.The error of LES is consequently decomposed into two parts:The first part is the error of FDNS with respect to DNS,which quantifies the influence of the filter operation.The second part is the difference between LES and FDNS induced by the error of LES in velocity field.By comparing the root-mean-square value and the wavenumber-frequency spectrum of the wall pressure fluctuation,it is found that the inaccuracy of the velocity fluctuations is the dominant source that induces the error of LES in the wall pressure fluctuation.The present study provides a basis on future LES studies of the wall pressure fluctuation.

A new numerical framework for large-eddy simulation of waves generated by objects piercing water surface

A novel numerical framework is developed for large-eddy simulation(LES) of interactions among air, water, and solid bodies. The motions of air and water are solved on a fixed block-structured mesh, with the air–water interface captured using the volume-of-fluid method. A new sub-grid scale stress model based on the vortex identifier is used to improve the robustness and efficiency of the simulation flows with air–water interface. The new framework is tested in the context of bow waves and Kelvin waves generated by a water-surface vehicle. Wave breaking at the bow of the vehicle is captured in LES. The LES results of wave geometry approaches the measurements progressively as the grid resolution is refined. The simulation results indicate that LES is a useful tool for studying wave dynamics of water-surface vehicles.

毛黏液星形细胞瘤的临床病理观察(英文)

Objective:The aim of this study was to study the clinicopathological and immunohistochemical features of pilomyxoid astrocytoma(PMA).Methods:The clinical and pathologic features in six cases of PMA were analyzed.Immunohistochemical staining for glial fibrillary acidic protein(GFAP),synaptophysin(Syn),Chromogranin A(CgA),cytokeratin(AE1/AE3),epithelial membrane antigen(EMA)and Ki67 was performed on paraffin-embedded sections.Results:Among the six cases,five occurred in female patients,one was male,the age at diagnosis ranged from 2 to 15 years.Four cases were located in the hypothalamic area and optic pathway,one case in the third ventricle,and one case in left parietal lobe.On imaging,PMAs often appears as well-circumscribed mass.Microscopically,the tumor was composed of monomorphous bipolar(piloid)cells setting in a prominent myxoid background with an angiocentric radiating growth pattern in some areas.PMA lacked biphasic pattern,Rosenthal fibers and eosinophilic granular bodies which were usually typical in a classic pilocytic astrocytoma(PA).Immunohistochemcal study showed that the tumor cells were diffusely positive for GFAP.Syn positive staining was observed in one case.The Ki67 labeling index measured less than 5%.Conclusion:PMA is a distinct aggressive variant of pilocytic astrocytoma with special histological and immunohistochemical features.It is typically a rare tumor of early childhood.Immunohistochemical staining for GFAP and Syn is helpful in differential diagnosis.

On Monotone Eigenvectors of a Max-<i>T </i>Fuzzy Matrix

The eigenvectors of a fuzzy matrix correspond to steady states of a complex discrete-events system, characterized by the given transition matrix and fuzzy state vectors. The descriptions of the eigenspace for matrices in the max-Lukasiewicz algebra, max-min algebra, max-nilpotent-min algebra, max-product algebra and max-drast algebra have been presented in previous papers. In this paper, we investigate the monotone eigenvectors in a max-T algebra, list some particular properties of the monotone eigenvectors in max-Lukasiewicz algebra, max-min algebra, max-nilpotent-min algebra, max-product algebra and max-drast algebra, respectively, and illustrate the relations among eigenspaces in these algebras by some examples.

Literature Review:Inclusive Education in Early Childhood

This literature review provides an overview of existing research and compares,and contrasts aims and definitions of Inclusive Education(IE)policies in China and Australia.It begins with the development of IE in each country;then it describes definition and concept of IE.The last section summarizes research in early childhood education in both countries.

Recombinant adeno-associated virus 8 vector in gene therapy:Opportunities and challenges

In recent years,significant breakthroughs have been made in the field of gene ther-apy.Adeno-associated virus(AAV)is one of the most promising gene therapy vectors and a powerful tool for delivering the gene of interest.Among the AAV vectors,AAV serotype 8(AAv8)has attracted much attention for its efficient and stable gene transfection into specific tissues.Currently,recombinant AAv8 has been widely used in gene therapy research on a va-riety of diseases,including genetic diseases,cancers,autoimmune diseases,and viral diseases.

乡村教师何以“留得住、教得好、有发展”?人力资源双重关注模型的跨层次效应研究

教育振兴是乡村振兴的基石,而乡村教师的发展则是教育振兴的关键。因此,如何打造“留得住、教得好、有发展”的高素质乡村教师队伍已经成为了目前的核心管理议题。然而,少有实证研究从组织层面探究人力资源管理系统对乡村教师工作结果和职业生涯的影响。基于资源保存理论,本文探讨了人力资源双重关注模型对乡村教师离职意向、工作绩效和职业成长的影响以及工作繁荣的中介作用。通过对51所学校和690位乡村教师的匹配数据进行跨层结构方程模型分析,研究发现:维持导向人力资源实践对乡村教师的离职意向有显著负向影响、对工作绩效有显著正向影响,对职业成长的影响不显著;绩效导向人力资源实践对乡村教师离职意向有显著负向影响、对工作绩效和职业成长均有显著正向影响;工作繁荣在人力资源双重关注模型与离职意向和工作绩效之间发挥着中介作用,工作繁荣在人力资源双重关注模型与职业成长之间没有发挥中介作用。本研究结果有助于优化乡村教师队伍的管理路径,激发乡村教师专业发展的内源性动力,完善乡村学校的人才培养模式。

Regulation of P450 TleB catalytic flow for the synthesis of sulfur-containing indole alkaloids by substrate structure-directed strategy and protein engineering

Indole alkaloids have attracted considerable attention from synthetic chemists and biochemists for their structural diversity and important biological activities.Compared with traditional organic synthesis methods,the strategy of using cytochrome P450s'extraordinary abilities to selectively activate carbon-hydrogen bonds to assist in the synthesis of various indole alkaloids has the characteristics of short synthetic route,mild conditions and high atomic economy.Here,we utilized P450 monooxygenases HinD and TleB to synthesize a novel 6/5/8 tricyclic product from(S)-N-((S)-1-(4-fluoro-1H-indol-3-yl)-3-hydroxypropan-2-yl)-2-mercapto-3-methylbutanamide through the substrate structure-directed strategy.TleB was more effective in catalyzing C–S coupling,and was used to synthesize a series of 6/5/8 tricyclic indololactam derivatives to provide drug candidates.Interestingly,the S–S coupling product was observed in HinD catalysis,which was a minor product in the wild-type TleB catalysis.With the help of protein engineering,we accurately regulated the catalytic flow and reversed the selectivity of TleB to obtain the S–S coupling product.At the same time,the reaction mechanism was reasonably speculated by means of site blocking and protein-substrate complex analysis.

Quantum Implementation of Numerical Methods for Convection-Diffusion Equations:Toward Computational Fluid Dynamics

We present quantum numerical methods for the typical initial boundary value problems(IBVPs)of convection-diffusion equations in fluid dynamics.The IBVP is discretized into a series of linear systems via finite difference methods and explicit time marching schemes.To solve these discrete systems in quantum computers,we design a series of quantum circuits,including four stages of encoding,amplification,adding source terms,and incorporating boundary conditions.In the encoding stage,the initial condition is encoded in the amplitudes of quantum registers as a state vector to take advantage of quantum algorithms in space complexity.In the following three stages,the discrete differential operators in classical computing are converted into unitary evolutions to satisfy the postulate in quantum systems.The related arithmetic calculations in quantum amplitudes are also realized to sum up the increments from these stages.The proposed quantum algorithm is implemented within the open-source quantum computing framework Qiskit[2].By simulating one-dimensional transient problems,including the Helmholtz equation,the Burgers’equation,and Navier-Stokes equations,we demonstrate the capability of quantum computers in fluid dynamics.

Impact of serum uric acid on left ventricular diastolic function in patients with autoimmune diseases

To the Editor:Left ventricular diastolic dysfunction(LVDD)is an unrecognized subclinical presentation of autoimmune diseases(AD)andcarries a worse prognosis.Elevated serum uric acid(SUA),as a_proinflammatory factor,is associatedwithchanges in cardiacfunction in the general population as,well as in those with cardiac diseases.

Numerical implementation and evaluation of resolvent-based estimation for space-time energy spectra in turbulent channel flows

Resolvent operator has been increasingly used to investigate turbulent flows and develop control strategies.Recently,Towne et al.(J Fluid Mech 883:A17,2020)proposed a resolvent-based estimation(RBE)method for predicting turbulent statistics in a channel flow.In this paper,we utilize the RBE method to predict the root-mean-square(RMS)and space-time energy spectra of streamwise velocity fluctuation,where the input is the space-time energy spectra at a reference horizontal plane located in the logarithmic layer and the output is the space-time energy spectra in the buffer layer.The explicit formulas for the RBE method are given in detail for numerical implementation.The results show the capability of the RBE method in the prediction of the convection velocity and bandwidth of the space-time energy spectra.Furthermore,we make a systematic evaluation of the performance of the RBE method by varying the input configurations,including the wall-normal location of the reference plane,the inclusion or exclusion of the pressure as an input variable,the implementation approach of the pressure boundary condition,and the choice of the window function.It is found that the results of both RMS velocity and space-time energy spectra obtained from the RBE method are sensitive to the location of the reference plane.However,the pressure boundary conditions and inclusion of pressure as an input do not cause significant change in the RMS velocity and space-time energy spectra.Although it does not influence the prediction of the RMS velocity,a window function is found crucial in the RBE method for the prediction of the space-time energy spectra.

A High-Contrast Autolysosome Probe for Detecting Interaction between Autophagosomes and Autolysosomes in Mitophagy

Comprehensive Summary,Autophagy is a multi-step cell metabolism process in which cells remove damaged and unwanted materials.During autophagy,autophagosomes fuse with lysosomes to form autophagosomes.Autophagosomal membrane components are recycled from autolysosomes through the autophagosomal components recycling(ACR),while lysosomal components circulate on the autolysosomal surface through the autophagic lysosome reformation(ALR)process.Autolysosomes contain components from autophagosomes and lysosomes.However,whether there is a fusion between autolysosome and autophagosome or lysosome at the organelle level remains unknown.In this study,a pH and viscosity dual-controlled mitochondria-targeting fluorescent probe Mito-Q was designed based on an asymmetric norcyanine to achieve the high-contrast imaging of mitochondria-containing autolysosomes.Mito-Q not only effectively detected mitochondrial viscosity changes and mitophagy with high sensitivity,but more importantly,the fusion of mitochondria-containing autolysosomes and autophagosomes(FMAA)was observed during autophagy by the real-time confocal imaging of HeLa cells.