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An Interpolation Method for Karhunen-Loève Expansion of Random Field Discretization

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Computer Modeling in Engineering & Sciences 2024年第1期138卷 245-272页

作者： zi Han Zhentian huang Department of Engineering Mechanics Hohai UniversityNanjing211100China College of Civil and Transportation Engineering Shenzhen UniversityGuangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and UtilizationInstitute of Deep Earth Sciences and Green EnergyShenzhenChina

In the context of global mean square error concerning the number of random variables in the representation,the Karhunen–Loève(KL)expansion is the optimal series expansion method for random field *** computational efficiency and accuracy of the KL expansion are contingent upon the accurate resolution of the Fredholm integral eigenvalue problem(IEVP).The paper proposes an interpolation method based on different interpolation basis functions such as moving least squares(MLS),least squares(LS),and finite element method(FEM)to solve the *** with the Galerkin method based on finite element or Legendre polynomials,the main advantage of the interpolation method is that,in the calculation of eigenvalues and eigenfunctions in one-dimensional random fields,the integral matrix containing covariance function only requires a single integral,which is less than a two-folded integral by the Galerkin *** effectiveness and computational efficiency of the proposed interpolation method are verified through various one-dimensional ***,based on theKL expansion and polynomial chaos expansion,the stochastic analysis of two-dimensional regular and irregular domains is conducted,and the basis function of the extended finite element method(XFEM)is introduced as the interpolation basis function in two-dimensional irregular domains to solve the IEVP.

关键词： Random field discretization KL expansion IEVP MLS FEM stochastic analysis

β-Phase Crystallization of Poly(vinylidene fluoride) in Poly(vinylidene fluoride)/Poly(ethyl methacrylate) Blends

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Chinese Journal of Polymer Science 2019年第1期37卷 94-100,4-7页

作者： zi-Jie huang Jing Jiang Gi Xue Dong-Shan Zhou Department of Polymer Science and Engineering School of Chemistry and Chemical Engineering Key Laboratory of High Performance Polymer Materials and Technology and The State Key Laboratory of Coordination Chemistry Nanjing University School of Physical Science and Technology Xinjiang Key Laboratory and Phase Transitions and Microstructures in Condensed Matters Yili Normal University

The nature of the crystalline phase of poly(vinylidene fluoride)(PVDF) in compatible blends with poly(ethyl methacrylate)(PEMA) was investigated by using X-ray diffraction(XRD), infrared microscopy(IR) and differential scanning calorimetry(DSC). The βphase of PVDF was observed after quenching from the melt and further annealing above the glass transition temperature over a composition range. The PVDF/PEMA blend with weight ratio of 3:2 has formed higher content of PVDF β crystals than others. By taking advantage of fast cooling rate of ultrafast differential scanning calorimeter(UFDSC), the quenching process of blends was modeled and tested simultaneously, and the melting behavior of β crystals in all blends was investigated. Three types of crystallization behavior of βphase PVDF in blends were found after quenching-annealing at different temperatures.

关键词： β-Crystal of PVDF Mesophase PVDF/PEMA blend Ultra-fast scanning calorimetry

Water Storage of Water-Based Enhanced Geothermal System Based on a 3D Thermal-Hydrologic-Mechanical Model

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Journal of Thermal Science 2022年第3期31卷 946-957页

作者： WANG Changlong huang Xinjie TANG gang ZHONG Dan School of Civil Engineering and Architecture Anhui University of TechnologyMa’anshan243002China Zhuhai Da Hengqin Science and Technology Development Co. LtdZhuhai519000China School of Safety Engineering China University of Mining and TechnologyXuzhou221116China

The thermal-hydrologic-mechanical(THM)coupled processes in water-based enhanced geothermal system(EGS)greatly influence the heat extraction performance of *** THM models have been proposed,however,there is a lack of detailed analysis of water storage,which is caused by the increments of reservoir porosity and water density,and the influence of water storage on the heat extraction performance needs to be *** this paper,a 3D THM model is established to simulate the water storage amount and heat extraction rate for a water-based *** 3D THM model is verified against an analytical ***,the influences of water storage are investigated,and comparisons between the THM and thermal-hydrologic(TH)processes are made for different initial reservoir *** results show that the increment of reservoir porosity has a larger influence on water storage than that of water *** ignoring water storage,the injection flow rate would be underestimated,while the production flow rate and heat extraction rate would be overestimated,and the reservoir would be cooled a little *** with the TH processes,the THM processes show larger cumulative water storage amount,higher steady-state heat extraction rate and higher cooling rate of reservoir,indicating that mechanical process has important influences on EGS *** higher initial reservoir porosity,the cumulative water storage amount is *** can be inferred that the water storage amount is related to the cooling rate of *** results of this paper show that water storage has a certain influence on the heat extraction rate,and that the mechanical process and initial reservoir porosity have important effects on the water storage amount,which should be simulated based on a THM model.

关键词： enhanced geothermal system thermal-hydrologic-mechanical model heat extraction water storage

Grain-size effect on dislocation source-limited hardening and ductilization in bulk pure Ni

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Journal of Materials Science & Technology 2023年第23期154卷 9-21页

作者： Kai Hu Jun Yi Bo huang gang Wang Institute of Materials School of Materials Science and Engineering Shanghai University Shanghai 200444 China

Dislocation source-limited hardening and ductilization is an effective strategy to obtain superior strength-ductility synergy in some engineering structural metals. Recent works demonstrated that the synergy could be enhanced by grain-size reduction. However, the mechanism of grain-size dependence is still a mystery. In this work, bulk pure Ni produced by electrodeposition and subsequent annealing, with grain sizes ranging from ∼20 nm to ∼20 µm, were methodically investigated to unravel the mechanism of the grain-size effect on dislocation source-limited hardening and ductilization. The high-density nano-twinning in the as-electrodeposited nanograined specimens exhibited better thermodynamic stability than the peers with random high-angle grain boundaries, leading to fine recrystallized grains with low-density dislocations. The low dislocation density enabled extra hardening beyond grain boundary strengthening via yield-point behavior with grain sizes ranging from ∼110 nm to ∼10 µm and extra ductilization over ∼500 nm. This work demonstrated that the prerequisite for dislocation source-limited hardening was that the dislocation density of the specimen should be lower than the size-dependent critical value of ((1.1 × 107 /d ) m^(–2), d is the grain size in unit of the meter) where a transition from forest-dominated hardening to dislocation source-limited hardening could occur. On the other hand, dislocation source-limited ductilization only worked when the grain size was comparable to/larger than the theoretical dislocation mean slip distance. Dislocation source-limited ductilization resulted from more room in grains for accumulation of dislocations and deformation nano-stacking faults enabling the higher work hardening rate. This work offered an altogether new avenue to obtain stronger and more ductile metallic materials through utilizing grain-size dependent dislocation source-limited hardening and ductilization.

关键词： Dislocation source-limited hardening Dislocation source-limited ductilization Grain size Yield point Hall-Petch slope

Method for triangular fuzzy multiple attribute decision making based on two-dimensional density operator method

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Journal of Systems Engineering and Electronics 2024年第1期35卷 178-185页

作者： LIN Youliang LI Wu LIU gang huang Dong School of Economics and Management Hunan Institute of Science and TechnologyYueyang 414000China Hunan Vocational College for Nationalities Yueyang 414000China School of Information Science and Engineering Hunan Institute of Science and TechnologyYueyang 414000China

Aiming at the triangular fuzzy(TF)multi-attribute decision making(MADM)problem with a preference for the distribution density of attribute(DDA),a decision making method with TF number two-dimensional density(TFTD)operator is proposed based on the density operator theory for the decision maker(DM).Firstly,a simple TF vector clustering method is proposed,which considers the feature of TF number and the geometric distance of ***,the least deviation sum of squares method is used in the program model to obtain the density weight ***,two TFTD operators are defined,and the MADM method based on the TFTD operator is ***,a numerical example is given to illustrate the superiority of this method,which can not only solve the TF MADM problem with a preference for the DDA but also help the DM make an overall comparison.

关键词： fuzzy decision making clustering density operator multi-attribute decision making(MADM)

Estimation of the unfrozen water content of saturated sandstones by ultrasonic velocity

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International Journal of Mining Science and Technology 2023年第6期33卷 733-746页

作者： Shibing huang Fei Liu gang Liu Shilin Yu School of Resources and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources Wuhan 430081China

The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing *** study addresses a new method to estimate the UWC of saturated sandstones at low temperature by using the ultrasonic *** velocity variations can be divided into the normal temperature stage(20 to 0℃),quick phase transition stage(0 to-5℃)and slow phase transition stage(-5 to-25℃).Most increment of ultrasonic velocity is completed in the quick phase transition stage and then turns to be almost a constant in the slow phase transition *** addition,the UWC is also measured by using nuclear magnetic resonance(NMR)*** is validated that the ultrasonic velocity and UWC have a similar change law against freezing and thawing *** WE(weighted equation)model is appropriate to estimate the UWC of saturated sandstones,in which the parameters have been accurately determined rather than by data *** addition,a linear relationship between UWC and ultrasonic velocity is built based on pore ice crystallization *** is evidenced that this linear function can be adopted to estimate the UWC at any freezing temperature by using P-wave velocity,which is simple,practical,and accurate enough compared with the WE model.

关键词： Ultrasonic velocity Freeze-thaw cycles Unfrozen water content Prediction function Hysteresis effect

Measurement of the free concentrations of alkyl phenols and bisphenol A to determine their biodegradation kinetics by activated sludge

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Chinese Science Bulletin 2007年第20期52卷 2766-2770页

作者： SHEN gang huang Jun YU gang Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

A negligible depletion-solid phase microextraction (nd-SPME) method is developed to measure free concentrations of two alkyl phenols (4-t-octylphenol, nonylphenol) and bisphenol A in activated sludge, with which aerobic biodegradation kinetics of three pollutants was determined. For the degradation of octylphenol, nonylphenol and bisphenol A, the apparent rate constant based on total concentration is 0.02, 0.01 and 0.03 h-1, respectively; with the half life being 34.9, 54.3 and 22.3 h correspondingly. Meanwhile, real rate constants based on free concentration are 0.74, 0.60 and 1.03 h-1, respectively; with the half life being 0.9, 1.2 and 0.7 h accordingly. Differences between two constants revealed that desorption of targeted pollutants from activated sludge should be the rate-limiting step. Compared to the rapid biodegradation of alkyl phenols and bisphenol A in free state, the desorption of pollutants from the sludge is relatively slow, which made the apparent biodegradation rate constants much lower.

关键词：烷基酚 2,2-双对羟苯基丙烷生物降解化学分析

Quantum simulation of lattice gauge theories on superconducting circuits:Quantum phase transition and quench dynamics

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Chinese Physics B 2022年第2期31卷 217-222页

作者： zi-Yong Ge Rui-Zhen huang zi-Yang Meng Heng Fan Beijing Nntional Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Kuvli Institute for Theoretical Sciences University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China Department of Physics and HKU-UCAS Joint Institute of Theoretical and Computational Physics The University of Hong Kong.Hong Kong SARChina CAS Center for Excellence in Topological Quantum Computation.University of Chinese Academy of Sciences.Beijing 100190 China

Recently,quantum simulation of low-dimensional lattice gauge theories(LGTs)has attracted many interests,which may improve our understanding of strongly correlated quantum many-body ***,we propose an implementation to approximate Z;LGT on superconducting quantum circuits,where the effective theory is a mixture of a LGT and a gauge-broken *** using matrix product state based methods,both the ground state properties and quench dynamics are systematically *** an increase of the transverse(electric)field,the system displays a quantum phase transition from a disordered phase to a translational symmetry breaking *** the ordered phase,an approximate Gauss law of the Z;LGT emerges in the ground ***,to shed light on the experiments,we also study the quench dynamics,where there is a dynamical signature of the spontaneous translational symmetry *** spreading of the single particle of matter degree is diffusive under the weak transverse field,while it is ballistic with small velocity for the strong ***,due to the emergent Gauss law under the strong transverse field,the matter degree can also exhibit confinement dynamics which leads to a strong suppression of the nearest-neighbor *** results pave the way for simulating the LGT on superconducting circuits,including the quantum phase transition and quench dynamics.

关键词： quantum simulation superconducting circuits lattice gauge theories

Solution of Wheeler-De Witt Equation, Potential Well and Tunnel Effect

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Communications in Theoretical Physics 2005年第4X期44卷 757-761页

作者： huang Yong-Chang WENG gang Institute of Applied Mathematics and Physics Beijing University of Technology Beijing 100022 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China

This paper uses the relation of the cosmic scale factor and scalar field to solve Wheeler-De Witt equation,gives the tunnel effect of the cosmic scale factor a and quantum potential well of scalar field, and makes it fit with the physics of cosmic quantum birth. By solving Wheeler-De Witt equation we achieve a general probability distribution of the cosmic birth, and give the analysis of cosmic quantum birth.

关键词： Wheeler-De Witt equation cosmology potential well tunnel effect