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study on a semi-resolved CFD-DEM method for rod-like particles in a gas-solid fluidized bed

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Particuology 2024年第4期87卷 20-36页

作者： Liping He Zhengxian Liu Yongzhi zhao Department of Mechanics School of Mechanical EngineeringTianjin UniversityTianjin300350China Insttute of Process quipment College of Energy EngineeringZhejiang UniversityHangzhou30027China

Based on a semi-resolved CFD-DEM coupling method,this study proposed a method that uses the minimum distance between the fluid grid and the particle boundary as a reference value to determine the degree of influence of the target fluid grid on the particle's drag force.A fluidized bed of rod-like particles was chosen as a typical case to investigate the effect of different fluid grid scales on various fluidized bed characteristic *** calculation performance of the semi-resolved and unre-solved CFD-DEM coupling algorithm on key fluidized bed characteristic parameters such as average pressure drop,particle frequency distribution with bed height,and particle orientation distribution were *** was found that the semi-resolved CFD-DEM coupling algorithm gradually obtained results with higher consistency with decreasing fluid grid scale for key parameters such as particle frequency distribution with bed height,particle orientation distribution,and time-history mixing index,exhibiting a phenomenon similar to grid independence in fluid *** comparing with experimental results,it was verified that the semi-resolved CFD-DEM coupling algorithm can be applied to simulate multi-granular gas-solid systems with fluid grid scales equivalent to particle *** algorithm solves the limitation of fluid grid scale in the unresolved CFD-DEM coupling framework and improves the grid adaptability of the CFD-DEM coupling simulation algorithm.

关键词： CFD-DEM semi-resolved method Fluid-solid flow Non-spherical particle Fluidized bed

Dynamic response of water-rich tunnel subjected to plane P wave considering excavation induced damage zone

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Underground space 2024年第2期15卷 113-130页

作者： Gongliang Xiang Ming Tao Rui zhao Huatao zhao Muhammad Burhan Memon Chengqing Wu school of Resources and safety Engineering Central South UniversityChangsha 410083China school of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China school of Civil and Environmental Engineering University of Technology SydneyNSW 2007Australia

The stability analysis of a deep buried tunnel subjected to dynamic disturbance is an important *** this study,the transient response has been obtained by establishing a water-rich tunnel model considering excavation damage zone(EDZ).Based on Biot’s two-phase dynamic theory and wave function expansion method,the analytical solution of dynamic response around the water-rich tunnel containing EDZ subjected to P wave is ***,Fourier transform and Duhamel’s integral technique is introduced to calculate the transient response,and the equivalent blasting curve is adopted to input excitation *** dimensionless parameters thickness N and shear modulus ratio lare defined to characterize the degree of damage in the surrounding rock,investigating the influencing factors,such as the parameters and the incident source *** results indicate that the dynamic stress concentration factor(DsCF)gradually decreases as the dimensionless parameters ***,it is observed that the DsCF is more sensitive to changes in the thickness parameter ***,the influence of the waveform parameters has been taken into account in the analysis of transient response,and the stress state and transfer process in each time stage of the EDZ are *** study establishes a theoretical foundation for comprehending the mechanical behavior and support design considerations associated with a deep-buried water-rich tunnel containing EDZ.

关键词： Water-rich tunnel Two-phase dynamic theory Wave scattering Transient response Dynamic stress concentration

Optimization of mixing speed and time to disperse the composite conductive agent composed of carbon black and graphene in lithium-ion battery slurry

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Particuology 2024年第9期92卷 1-12页

作者： Zhilong Wang Jialong Tu Xinhao Yu Feixiang Li Zhenzhen zhao Yahui Cui Tong zhao Faculty of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an710048China

This paper proposed an optimal approach to disperse the composite conductive agent which is composed of carbon black(CB)and graphene(Gr)within lithium-ion battery(LIB)slurry with different mixing speeds and mixing *** internal structures of LIB slurry are characterized by Electrochemical Impedance spectroscopy,scanning Electron Microscopy,and Raman ***,a composite conductive solution is prepared by mixing the composite conductive agent with NMP solvent under the conditions of five different mixing speeds n_(1)(n_(1)=1000,1100,1200,1300,1400 rpm)in the case of mixing time t_(1)=10 ***,LIB slurry is prepared by blending the composite conductive solution,LiCoO_(2)and PVDF-NMP solution under the conditions of five different mixing speeds n_(2)(n_(2)=1000±280,1100±280,1200±280,1300±280,1400±280 rpm)in the case of mixing time t_(2)=6 *** analyzing the internal structure of different LIB slurries,it shows that in the case of n_(1)=n_(2)=1200 rpm,a conductive network structure is well formed within LIB ***,in order to determine the optimal time to prepare the composite conductive solution for LIB slurry,nine different t_(1)(t_(1)=0,10,20,30,40,50,60,70,80 min)are *** analyzing the internal structure of different LIB slurries,a well-formed conductive network structure and a uniformly distributed composite conductive agent are deduced in LIB slurry when t_(1)=50 ***,it can be concluded that the composite conductive agent composed of CB and Gr is able to be uniformly dispersed in LIB slurry by establishing a well-formed conductive network structure under the optimal mixing speed n_(1)=n_(2)=1200 rpm and the optimal mixing time t_(1)=50 min,t_(2)=6 *** kind of the internal structure has the potential to be used to further analyze the dispersion characterizations of LIB slurry under different composite conductive agent and CB/Gr ratios with the aim of improving the final performance of LIB.

关键词： Lithium-ion battery slurry Composite conductive agent Carbon black Graphene

Two Matrix Theorems Arising from Nilpotent Groups

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Algebra Colloquium 2024年第3期31卷 499-504页

作者： Jing zhao Heguo Liu school of Mathematics and statistics Hainan University Haikou 570228China

For a nilpotent group G without π-torsion,and x,y ∈ G,if x^(n)=y^(n) for a T-number n,then x=y;if x^(m)y^(n)=y^(n)x^(m) for n-numbers m,n,then xy=*** is a wellknown result in group *** this paper,we prove two analogous theorems on matrices,which have independence ***,let m be a given positive integer and A a complex square matrix satisfying that(i)all eigenvalues of A are nonnegative,and(i)rank A^(2)=rank A;then A has a unique m-th root X with rank X^(2)=rank X,all eigenvalues of X are nonnegative,and moreover there is a polynomial f(λ)with X=f(A).In addition,let A and B be complex n×n matrices with all eigenvalues nonnegative,and rank A^(2)=rank A,rank B^(2)=rank B;then(i)A=B when A^(r)=B^(r) for some positive integer r,and(i)AB=BA when A^(s)B^(t)=B^(t)A^(s) for two positive integers s and t.

关键词： nilpotent group root matrix Chinese remainder theorem

Monolayer mesoporous nanosheets with surface asymmetry via a dual-emulsion-directed monomicelle assembly

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Amorphous oxide semiconductor for monolithic 3D DRAM: an enabler or passer-by?

结构化学 2024年第2期43卷 1-3页

作者： Yujuan zhao Zaiwang zhao College of Energy Materials and Chemistry College of Chemistry and Chemical EngineeringInner Mongolia UniversityHohhot010070China

Functional mesoporous materials,based on IUPAC,are a type of porous materials with a uniform pore size ranging from 2 to 50 *** the 1980s,the existing zeolites or microporous materials with small pore sizes(less than 1.2 nm)have some limitations in practical applications,especially for large molecule conversion and *** by these motivations,the exploration of mesoporous materials has been widely *** the early 1990s,the mesoporous materials including or-dered M41s[1]mesoporous silicate molecular sieves and large-pore mesoporous silica sBA-15[2]were prepared when templated by the quaternary ammonium cationic surfactant or the amphiphilic triblock copolymer *** high thermal stability of such porous materials and good repeatability of methods have aroused widespread interest in both academic and industrial domains.

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National science Review 2024年第3期11卷 19-20页

作者： shujuan Mao Guilei Wang Chao zhao Beijing superstring Academy of Memory Technology

since dynamic random-access memory(DRAM) was invented in 1968 and put to market in the 1970s, 1 transistor plus 1 capacitor(1T1C)(Fig. 1a) cells have been used to take advantage of their structural simplicity and ease...

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EPR-Net: constructing a non-equilibrium potential landscape via a variational force projection formulation

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National science Review 2024年第7期11卷 135-147页

作者： Yue zhao Wei Zhang Tiejun Li Center for Data science Peking University Zuse Institute Berlin Department of Mathematics and Computer science Freie Universit?t Berlin Laboratory of Mathematics and Applied Mathematics(LMAM)and school of Mathematical sciences Peking University Center for Machine Learning Research Peking University

We present EPR-Net, a novel and effective deep learning approach that tackles a crucial challenge in biophysics: constructing potential landscapes for high-dimensional non-equilibrium steady-state ***-Net leverages a nice mathematical fact that the desired negative potential gradient is simply the orthogonal projection of the driving force of the underlying dynamics in a weighted inner-product ***, our loss function has an intimate connection with the steady entropy production rate(EPR),enabling simultaneous landscape construction and EPR estimation. We introduce an enhanced learning strategy for systems with small noise, and extend our framework to include dimensionality reduction and the state-dependent diffusion coefficient case in a unified fashion. Comparative evaluations on benchmark problems demonstrate the superior accuracy, effectiveness and robustness of EPR-Net compared to existing methods. We apply our approach to challenging biophysical problems, such as an eight-dimensional(8D)limit cycle and a 52D multi-stability problem, which provide accurate solutions and interesting insights on constructed landscapes. With its versatility and power, EPR-Net offers a promising solution for diverse landscape construction problems in biophysics.

关键词： high-dimensional potential landscape non-equilibrium system entropy production rate dimensionality reduction deep learning

A rigorous real-time acoustic positioning method for ocean bottom seismic exploration

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satellite Navigation 2024年第1期5卷 168-190页

作者： Jinye Ma shouchuan Fang Jianhu zhao school of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Institute of Marine science and Technology Wuhan UniversityWuhan430079China surveying service Center BGP Inc.CNPCZhuozhou072751HebeiChina

The conventional technique for positioning seafloor geophones in ocean bottom seismic exploration encounters several challenges,including the significant impact of outliers on positioning results,underutilization of high-precision observations,and low efficiency in real-time data *** issues inevitably affect the quality of seismic exploration *** address these challenges and enhance the accuracy of geophone positioning,this paper proposes a rigorous real-time acoustic positioning method for geophones based on sequential adjustment and Baarda's outlier detection *** proposed method comprises three key steps:grouping the original acoustic observations,constructing the intra-group acoustic positioning model,and synthesizing the positioning results across the different *** validity and practicality of this approach are confirmed through a simulation experiment as well as the field experiment conducted in the Bohai sea,*** results demonstrate that the proposed method effectively eliminates outliers in the original observations and maximizes the utilization of high-quality *** to traditional acoustic positioning methods,it significantly reduces positioning errors from meters to decimeters,and in some cases can achieve centimeter-level *** the sound velocity profile in the operating sea area is measured,the method can attain the posterior standard deviation at the millimeter level and positioning errors within 10 *** the sound velocity profile is unknown,the method can achieve the posterior standard deviation at centimeter-level and positioning errors of approximately 20 cm.

关键词： Ocean bottom seismic exploration Geophone positioning Acoustic positioning method sequential adjustment Outlier detection

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肥厚性心肌病发生替代性纤维化的模式

国际医学放射学杂志 2022年第2期 233-233页

作者： J.Liu s.zhao s.Yu G.Wu D.Wang L.Liu 朱珍

摘要心肌替代性纤维化是肥厚性心肌病（HCM）的主要组织学特征之一，但其特征尚未明确。目的阐明HCM替代性纤维化的特征，并评估局部纤维化程度的预后价值。资料

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