Uncertainty-Aware Physical Simulation of Neural Radiance Fields for Fluids

This paper presents a novel framework aimed at quantifying uncertainties associated with the 3D reconstruction of smoke from2Dimages.This approach reconstructs color and density fields from 2D images using Neural Radiance Field(NeRF)and improves image quality using frequency regularization.The NeRF model is obtained via joint training ofmultiple artificial neural networks,whereby the expectation and standard deviation of density fields and RGB values can be evaluated for each pixel.In addition,customized physics-informed neural network(PINN)with residual blocks and two-layer activation functions are utilized to input the density fields of the NeRF into Navier-Stokes equations and convection-diffusion equations to reconstruct the velocity field.The velocity uncertainties are also evaluated through ensemble learning.The effectiveness of the proposed algorithm is demonstrated through numerical examples.The presentmethod is an important step towards downstream tasks such as reliability analysis and robust optimization in engineering design.

A Subdivision-Based Combined Shape and Topology Optimization in Acoustics

We propose a combined shape and topology optimization approach in this research for 3D acoustics by using the isogeometric boundary element method with subdivision surfaces.The existing structural optimization methods mainly contain shape and topology schemes,with the former changing the surface geometric profile of the structure and the latter changing thematerial distribution topology or hole topology of the structure.In the present acoustic performance optimization,the coordinates of the control points in the subdivision surfaces fine mesh are selected as the shape design parameters of the structure,the artificial density of the sound absorbing material covered on the structure surface is set as the topology design parameter,and the combined topology and shape optimization approach is established through the sound field analysis of the subdivision surfaces boundary element method as a bridge.The topology and shape sensitivities of the approach are calculated using the adjoint variable method,which ensures the efficiency of the optimization.The geometric jaggedness and material distribution discontinuities that appear in the optimization process are overcome to a certain degree by the multiresolution method and solid isotropic material with penalization.Numerical examples are given to validate the effectiveness of the presented optimization approach.

The extraction of effective components and an antioxidant activity study of Tulipa edulis

Plant extracts from natural sources are an excellent choice for food additives and natural antioxidants.In this study,the active components of Tulipa edulis were extracted and analysed,and their antioxidant capacity was measured.Then,the crude extract mixture was separated and purified using a Sephadex LH-20 gel,and the antioxidant activity of the purified products was determined.Human umbilical vein endothelial human umbilical vein endothelial cells(HUVEC)cells were treated with 35 mmol/L glucose to construct a model of oxidative stress.Then,the cells were treated with the active component to observe whether the products of T.edulis could have a good protective effect on HUVEC cells induced by glucose.Transcriptome analysis was also performed on HUVEC cells after same treatment to explore the possible mechanism of the component F2 protecting HUVEC cells from oxidative stress induced by high glucose.The results showed that component F2 obtained from T.edulis has strong antioxidant activity.Moreover,F2 can play a strong antioxidant protective role in HUVEC cells.Meanwhile,the gene expression of heme oxygenase 1(HO-1),γ-glutamyl cysteine ligase catalytic subunit(GCLC)and NAD(P)H quinone oxidoreductase-1(NQO1)in HUVEC cells was up-regulated after treated with F2.This study provides reference value for the further development and application of T.edulis and the d evelopment of functional food.

Recent Advances of Deep Learning in Geological Hazard Forecasting

Geological hazard is an adverse geological condition that can cause loss of life and property.Accurate prediction and analysis of geological hazards is an important and challenging task.In the past decade,there has been a great expansion of geohazard detection data and advancement in data-driven simulation techniques.In particular,great efforts have been made in applying deep learning to predict geohazards.To understand the recent progress in this field,this paper provides an overview of the commonly used data sources and deep neural networks in the prediction of a variety of geological hazards.

A systematic review of steel bridge deck pavement in China

As an important part of steel bridge deck,the engineering quality and service condition of steel bridge deck pavement(SBDP)directly affects the capacity and operational efficiency of the bridge.This paper reviews the history of the development of SBDP in China over the past 20 years from the exploration stage,rapid development stage and prosperity stage.The development and application of SBDP at different stages are discussed in terms of materials,structure,design,performance evaluation,maintenance and rehabilitation,respectively.The advantages and disadvantages of different pavement materials and structures,and the application of different research methods are summarized.The review shows that the improvement of pavement materials and structures and the development of new materials should be further studied on the multi-scale to enhance the durability of pavement materials,so as to extend the service life of pavements.The design method of SBDP related to the synergistic effect of vehicle,pavement and bridge should be established,and the design concept and method standard of rigid base pavement structure should be improved and formulate a complete design standard.In addition,multi-disease intelligent identification system and equipment should be studied to track the entire course of disease development in real time.And it is necessary to develop appropriate algorithms to select and classify the complex data of disease and maintenance history.

Isogeometric Boundary Element Analysis for 2D Transient Heat Conduction Problem with Radial Integration Method

This paper presents an isogeometric boundary element method(IGABEM)for transient heat conduction analysis.The Non-Uniform Rational B-spline(NURBS)basis functions,which are used to construct the geometry of the structures,are employed to discretize the physical unknowns in the boundary integral formulations of the governing equations.Bezier extraction technique is employed to accelerate the evaluation of NURBS basis functions.We adopt a radial integration method to address the additional domain integrals.The numerical examples demonstrate the advantage of IGABEM in dimension reduction and the seamless connection between CAD and numerical analysis.

The normal cell proliferation and wound healing effect of polysaccharides from Ganoderma amboinense

To study the cell proliferation and wound healing activity of polysaccharides from Ganoderma amboinense(GAMPS),the polysaccharide was extracted by water extraction and alcohol precipitation method,and its monosaccharide composition and molecular weight were analyzed.The effects of different concentrations of GAMPS on the cell proliferation were determined by cell survival rate test,and the wound healing ability of GAMPS to NIH/3T3 cells was detected.The preliminary evaluation of the antioxidant ability of GAMPS was conducted by the oxygen radical absorbance capacity(ORAC).The results showed that the GAMPS was composed of glucose,mannose,and galactose at a molar ratio of 67.62:14.07:7.50,and the weightaverage molecular weights were 5.439×10^(6) and 1.704×10^(5) g/mol by using high-performance gel-permeation chromatography-multiple angle laser scatter(HPGPC-MALS)analysis.GAMPS(0.2μg/μL)showed the strongest proliferation ability to THP-1 cells,with cell survival rate of 178.7%.The wound healing effect of GAMPS(0.1μg/μL)was obvious on NIH/3T3 and 3.75μg/μL of GAMPS showed the strongest total antioxidant ability.All the results indicate that GAMPS promotes cell proliferation,and has cell wound healing effect and strong antioxidant activity.The results provide theoretical foundation for the development and utilization of GAMPS.

Monte Carlo Simulation of Fractures Using Isogeometric Boundary Element Methods Based on POD-RBF

This paper presents a novel framework for stochastic analysis of linear elastic fracture problems.Monte Carlo simulation(MCs)is adopted to address the multi-dimensional uncertainties,whose computation cost is reduced by combination of Proper Orthogonal Decomposition(POD)and the Radial Basis Function(RBF).In order to avoid re-meshing and retain the geometric exactness,isogeometric boundary element method(IGABEM)is employed for simulation,in which the Non-Uniform Rational B-splines(NURBS)are employed for representing the crack surfaces and discretizing dual boundary integral equations.The stress intensity factors(SIFs)are extracted by M integral method.The numerical examples simulate several cracked structures with various uncertain parameters such as load effects,materials,geometric dimensions,and the results are verified by comparison with the analytical solutions.

Machine Learning Enhanced Boundary Element Method:Prediction of Gaussian Quadrature Points

This paper applies a machine learning technique to find a general and efficient numerical integration scheme for boundary element methods.A model based on the neural network multi-classification algorithmis constructed to find the minimum number of Gaussian quadrature points satisfying the given accuracy.The constructed model is trained by using a large amount of data calculated in the traditional boundary element method and the optimal network architecture is selected.The two-dimensional potential problem of a circular structure is tested and analyzed based on the determined model,and the accuracy of the model is about 90%.Finally,by incorporating the predicted Gaussian quadrature points into the boundary element analysis,we find that the numerical solution and the analytical solution are in good agreement,which verifies the robustness of the proposed method.

Noise Pollution Reduction through a Novel Optimization Procedure in Passive Control Methods

This paper proposes a novel optimization framework in passive control techniques to reduce noise pollution.The geometries of the structures are represented by Catmull-Clark subdivision surfaces,which are able to build gap-free Computer-Aided Design models and meanwhile tackle the extraordinary points that are commonly encountered in geometricmodelling.The acoustic fields are simulated using the isogeometric boundary elementmethod,and a density-based topology optimization is conducted to optimize distribution of sound-absorbing materials adhered to structural surfaces.The approach enables one to perform acoustic optimization from Computer-Aided Design models directly without needingmeshing and volume parameterization,thereby avoiding the geometric errors and time-consuming preprocessing steps in conventional simulation and optimization methods.The effectiveness of the present method is demonstrated by three dimensional numerical examples.

Resolving Domain Integral Issues in Isogeometric Boundary Element Methods via Radial Integration:A Study of Thermoelastic Analysis

The paper applied the isogeometric boundary element method(IGABEM)to thermoelastic problems.The Non-Uniform Rational B-splines(NURBS)used to construct geometric models are employed to discretize the boundary integral formulation of the governing equation.Due to the existence of thermal stress,the domain integral term appears in the boundary integral equation.We resolve this problem by incorporating radial integration method into IGABEM which converts the domain integral to the boundary integral.In this way,IGABEM can maintain its advantages in dimensionality reduction and more importantly,seamless integration of CAD and numerical analysis based on boundary representation.The algorithm is verified by numerical examples.

Overview of Distribution Network Fault Location

According to the existing research, the fault section location and fault location of passive distribution network and active distribution network are reviewed. Among them, fault location of passive distribution network mainly introduces fault segment location based on transient state and steady state quantity and fault location based on transient quantity. The active distribution network mainly introduces the fault segment location based on the current amount and the switching capacity based on the distribution network topology. On this basis, the difficulties of fault location in the distribution network at present are analyzed, and the future development is prospected.

A simple practical balloon anchoring technique within the guide catheter for chronic total occlusion (CTO) of the coronary artery

Dear Editor： Chronic total occlusions （CTOs） of the coronary artery are commonly encountered complex lesionst11. Percutaneous coronary intervention （PCI） for CTO is technically challenging due to low procedural success ratesTM. Microcatheter is one of the important devices for treatment of CTOTM. It has been widely used attributed to the excellent crossability whenever angula- tion and tortuousity of the coronary artery is encoun- tered. In the process, the microcatheter has to be withdrawn from the guide wire after the wire is proved to locate in the true lumen.

The new insights of hyperbaric oxygen therapy:focus on inflammatory bowel disease

Inflammatory bowel diseases(IBD),with an increasing incidence,pose a significant health burden.Although there have been significant advances in the treatment of IBD,more progress is still needed.Hyperbaric oxygen therapy(HBOT)has been shown to treat a host of conditions such as carbon monoxide poisoning,decompression sickness,and gas gangrene.In the last few years,there has been an increase in research into the use of HBOT as an adjunct to conventional treatment for IBD.Related research has shown that HBOT may exert its therapeutic effects by decreasing oxidative stress,inhibiting mucosal inflammation,promoting ulcer healing,influencing gut microbes,and reducing the incidence of IBD complications.This paper aims to provide a comprehensive review of experimental and clinical trials exploring HBOT as a supplement to IBD treatment strategies.

High-temperature wear mechanisms of TiNbWN films:Role of nanocrystalline oxides formation

Réfractory high/medium entropy nitrides(HENs/MENs)exhibit comprehensive application prospects as protective films on mechanical parts,particularly those subjected to sliding contacts at elevated temperatures.In this study,a new MEN system TiNbWN,forming a single fc solution,is designed and its wear performance at temperatures ranging from 25 to 750℃is explored.The wear mechanisms can be rationalized by examining the subsurface microstructural evolutions using the transmission electron microscopy as well as calculating the phase diagrams and interfacial adhesion behavior employing calculation of phase diagram(CALPHAD)and density functional theory(DFT).To be specific,increased wear losses occur in a temperature range of 25-600℃,being predominantly caused by the thermally-induced hardness degradation;whereas at the ultimate temperature(750℃),the wear loss is refrained due to the formation of nanocrystalline oxides(WnO_(3n-2r)TiO_(2),and TiOx),as synergistically revealed by microscopy and CALPHAD,which not only enhance the mechanical properties of the pristine nitride film,but also act as solid lubricants,reducing the interfacial adhesion.Thus,our work delineates the role of the in situ formed nanocrystalline oxides in the wear mechanism transition of TiNbWN thin films,which could shed light on the high-temperature wear behavior of refractory HEN/MENfilms.

先进嵌段共聚物光刻胶设计

嵌段共聚物光刻胶引导自组装是先进制程半导体制造的候选方案之一。第一代嵌段共聚物光刻胶的典型代表是聚苯乙烯-聚甲基丙烯酸甲酯二嵌段共聚物,受限于自身较低的相互作用参数(χ),最小半周期(0.5L0)为11 nm。第二代嵌段共聚物光刻胶的特征是具有高相互作用参数(实现10 nm以下图案化),但是由于两个嵌段的表面能(γ)差异较大,需要引入额外的溶剂退火或者涂层工艺。为了解决上述问题,国内外学者发展了第三代嵌段共聚物光刻胶,不仅具有较高的相互作用参数,还具有接近的表面能(高χ近γ),适用于工业友好的热退火工艺引导自组装。最近,基于材料基因组计划概念,将多种共变特性赋予单一材料的第四代嵌段共聚物光刻胶问世,可以实现高通量合成建立嵌段共聚物库,通过调控χ和χN满足不同的应用场景(0.5L0=4~10 nm),还可以免除热退火工艺中涂覆中性层步骤,简化了工艺流程。本文总结了第三代和第四代先进嵌段共聚物光刻胶的设计,并且对相关领域存在的挑战与机遇进行了探讨和展望。

Cancer metabolism and tumor microenvironment:fostering each other?

The changes associated with malignancy are not only in cancer cells but also in environment in which cancer cells live.Metabolic reprogramming supports tumor cells’high demand of biogenesis for their rapid proliferation,and helps tumor cells to survive under certain genetic or environmental stresses.Emerging evidence suggests that metabolic alteration is ultimately and tightly associated with genetic changes,in particular the dysregulation of key oncogenic and tumor suppressive signaling pathways.Cancer cells activate HIF signaling even in the presence of oxygen and in the absence of growth factor stimulation.This cancer metabolic phenotype,described firstly by German physiologist Otto Warburg,ensures enhanced glycolytic metabolism for the biosynthesis of macromolecules.The conception of metabolite signaling,i.e.,metabolites are regulators of cell signaling,provides novel insights into how reactive oxygen species(ROS)and other metabolites deregulation may regulate redox homeostasis,epigenetics,and proliferation of cancer cells.Moreover,the unveiling of noncanonical functions of metabolic enzymes,such as the moonlighting functions of phosphoglycerate kinase 1(PGK1),reassures the importance of metabolism in cancer development.The metabolic,microRNAs,and ncRNAs alterations in cancer cells can be sorted and delivered either to intercellular matrix or to cancer adjacent cells to shape cancer microenvironment via media such as exosome.Among them,cancer microenvironmental cells are immune cells which exert profound effects on cancer cells.Understanding of all these processes is a prerequisite for the development of a more effective strategy to contain cancers.

Graphitizing N-doped mesoporous carbon nanospheres via facile single atom iron growth for highly efficient oxygen reduction reaction

Single atom catalyst is of great importance for the oxygen reduction reaction(ORR).However,facile preparation of single atom catalyst without using well-designed precursors or labor-intensive acid leaching remains an urgent challenge.Herein,a simple pyrolysis of Fe3+-loaded mesoporous phenolic resin(mPF)-melamine precursor is used to prepare the single atom iron-anchored N-doped mesoporous graphitic carbon nanospheres(Fe/N-MGN).Investigation of the synthesis reveals the appropriate Fe-assisted catalysis effect and mPF template effect,which not only spurs the highly graphitic porous framework of Fe/N-MGN with plentiful pyridinic N/graphitic N,but also assures the dispersed single atom Fe anchoring without elaborated procedures.As a result,the as-synthesized Fe/N-MGN demonstrates high catalytic activity,good durability and excellent methanol tolerance for ORR.This work promises a facile method to regulate the graphitic carbon growth and single atom Fe loading for the highly efficient electrocatalysis.

Facile growth of ultra-small Pd nanoparticles on zeolite-templated mesocellular graphene foam for enhanced alcohol electrooxidation

Labor-saving preparation of highly active electrocatalysts for alcohols oxidation, especially for the ethylene glycol and glycerol electrooxidation is of great importance for the development of fuel cells. Herein, mesocellular graphene foam (MGF) constructed by ultrathin nanosheets were prepared using lamellar MCM-22 zeolite as template and then ultra-small Pd NPs were facile grew on it via the stabilizer-free synthesis. Detailed characterizations showed that the obtained Pd/MGF had large surface area, hierarchical porous architecture, semi-graphitic framework and dispersed Pd NPs an chori ng. Electrochemical measurements dem on strated that Pd/MGF possessed the higher catalytic activity (1.7-2.9 fold higher) and stability for the different alcohols electrooxidation, especially for the ethylene glycol and glycerol electrooxidation in the alkaline solution, than the commercial Pd/C (10 wt.%) catalyst. Reaction kinetics analysis revealed the expanded diffusion-controlled process of Pd/MGF as compared to Pd/C. These findings promised a potential electrocatalyst for direct alcohol fuel cells (DAFC), especially for the direct ethylene glycol or glycerol fuel cells with high energy density.

Ultra-small MoS_(2)nanodots-incorporated mesoporous silica nanospheres for pH-sensitive drug delivery and CT imaging

Functionalization of mesoporous silica spheres with well-dispersed and ultra-small nanodots to exert their synergistic effects for biomedical applications has been considered to be an urgent challenge.Herein,homogeneously incorporation of ultra-small and monodispersed MoS_(2) nanodots in the mesoporous silica nanospheres(MSN)was achieved by a facile one-step solvothermal reaction.The as-synthesized UsMSND@MSN possessed uniform size(~115 nm)and favorable biocompatibility inherited from MSN.The dispersed UsMSND within MSN could act as anchoring sites for aromatic anti-cancer drug DOX loading,and consequently achieved pH-responsive release based on the specialπ-π/electrostatic interactions with the DOX molecules.More importantly,the well-dispersed UsMSND in MSN could function as the non-toxic contrast agent for the sensitive in vivo CT imaging in various tumors including breast cancer and glioma with different sections.This work promises a good strategy for dispersed incorporation of UsMSND into MSN as an excellent pH-responsive platform for simultaneous cancer imaging and therapy.