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Rare Metals 2007年第S1期26卷 14-19页

作者： ri E H ri Hosen DOROFEEV s V kUHARENkO E B Department of Foundry and Process Metallurgy Metrology and Material Inspection LaboratoryPacific National University

The results of research on influence of an irradiation of a liquid phase by nanosecond electromagnetic impulses(NEMI) on processes of crystallization and structurization,physicomechanical and operational properties of... 详细信息

关键词： generator NEMI nanosecond electromagnetic impulses corrosion resistant heat resistance

Assessing cooling energy reduction potentials by retrofitting traditional cavity walls into passively ventilated cavity walls

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Building simulation 2021年第4期14卷 1295-1309页

作者： ri Na Zhigang shen Department of Civil and Environmental Engineering University of DelawareNewarkDE19716USA The Durham school of Architecture Engineering and Construction University of Nebraska LincolnLincolnNE68588USA

A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy *** low-cost energy retrofit solutions that do not disrupt occupants’daily life during the retrofitting is the key to successful building energy retrofit *** this paper,a novel and low-cost exterior wall retrofitting solution is introduced,and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and *** primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall *** intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate *** quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics(CFD)model,which is validated by benchmarking its prediction against the published experimental case *** outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’summer cooling load in hot climate *** applicability of this solution is not limited to retrofitting existing *** energy-efficient building designs can also adopt this solution in their envelope systems.

关键词： low-cost energy retrofit building envelope cavity wall stack effect space cooling energy reduction CFD

A Remark on Leray's Problem on stationary Navier–stokes Flows with Large Fluxes in Infinite Cylindrical Domains

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Acta Mathematica sinica,English series 2015年第10期31卷 1571-1581页

作者： Myong-Hwan ri Institute of Mathematics State Academy of SciencesPyongyang DPR Korea

We consider Leray＇s problem on stationary Navier stokes flows with arbitrary large fluxes in an unbounded cylinder with several exits to infinity. For a stationary Navier stokes flow with large fluxes in the unbounded cylinder, we prove that, if the difference between the pressure of the main flow and the pressure of the Poiseuille flow with the same flux in a branch of the cylinder remains bounded at ｜x｜→∞, then the flow behaves at infinity of the branch like the Poiseuille flow.

关键词： Leray's problem Navier-stokes equations large flux unbounded cylindrical domains

Regularity for 3D Navier–stokes Equations Based on Energy Distribution at Wavenumber Bands

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Acta Mathematica sinica,English series 2019年第8期35卷 1377-1392页

作者： Myong-Hwan ri Institute of Mathematics State Academy of SciencesDPR Korea

We present some regularity criteria for the Leray–Hopf weak solutions to the Cauchy problem for 3D Navier–stokes equations based on energy distribution at wavenumber bands. We show sufficient conditions for regularity based on the ratios of energy dissipation rates at sufficiently high wavenumber bands and neighboring medium wavenumber bands. Moreover, we give a regularity criterion based on relations between energy at high and low wavenumber bands.

关键词： Navier-stokes equations global regularity energy transfer

First-principles simulation and experimental evidence for improvement of transmittance in ZnO films

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Progress in Natural science:Materials International 2011年第1期21卷 40-45页

作者： ri-ichi MURAkAMI Department of Mechanical Engineering The University of Tokushima2-1 Minamijosanjima-choTokushima 770-8506Japan

ZnO/Ag/glass films were prepared by a DC magnetron sputtering system,which exhibit both excellent properties of high conductivity and high ***,an enhancement of transmission of ZnO films was observed after brought into contact to a silver layer,but the understanding of experimental findings for the enhancement of transmission was ***,the first-principles simulations of electrical and optical properties were utilized using the density functional theory with local-density approximations or generalized-gradient *** crystal structure of ZnO or Ag was imported from the Material studio *** periodic supercell has the same atomic ratio with the experimental structure and was optimized using the CAsTEP package in Material *** to the calculation results,the enhancement in transmission is attributed to the surface plasmon polariton in the asymmetric structure films.

关键词： first-principles transparent conductive oxide ZnO transmittance surface plasmon polaritons

Cosmological constraints on the background dynamics of a two-field nonsingular bounce model

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Chinese Physics C 2024年第11期48卷 149-155页

作者： kang song ri sin Chol Hwang Hyon Chol ri Department of Physics Kim Il Sung UniversityRyongnam DongTaesong District PyongyangDemocratic People's Republic of Korea

In this study,we consider a nonsingular two-field bounce scenario with non-minimal kinetic coupling between two scalar *** derive constraints on the model parameters from the finiteness of the physical quantities at the classical level and from the relation between the late-time accelerated expansion and particle production up to the bounce *** then determine the allowed parameter space for the model.

关键词： bounce universe parameter space

A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-ri Zhang Yong-Hua shi Bionic Robot Research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China guangdong Provincial Engineering Research Center for special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry gradient analysis Real-time detection

Influence of indoor airflow on airborne disease transmission in a classroom

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Building simulation 2024年第3期17卷 355-370页

作者： Mojtaba Zabihi ri Li Joshua Brinkerhoff school of Engineering Faculty of Applied ScienceUniversity of British ColumbiaKelownaCanada

It has been widely accepted that the most effective way to mitigate airborne disease transmission in an indoor space is to increase the ventilation airflow,measured in air change per hour(ACH).However,increasing ACH did not effectively prevent the spread of *** better understand the role of ACH and airflow large-scale patterns,a comprehensive fully transient computational fluid dynamics(CFD)simulation of two-phase flows based on a discrete phase model(DPM)was performed in a university classroom setting with people *** investigations encompass various particle sizes,ventilation layouts,and flow *** findings demonstrated that the particle size threshold at which particles are deemed airborne is highly influenced by the background flow strength and large-scale flow pattern,ranging from 5µm to 10µm in the cases *** effects of occupants are significant and must be precisely accounted for in respiratory particle transport *** enhanced ventilation design(UFAD-CDR)for university classrooms is introduced that places a premium on mitigating airborne disease *** to the baseline design at the same ACH,this design successfully reduced the maximum number density of respiratory particles by up to 85%.A novel airflow-related parameter,Horizontality,is introduced to quantify and connect the large-scale airflow pattern with indoor aerosol *** underscores that ACH alone cannot ensure or regulate air *** addition to the necessary ACH for air exchange,minimizing horizontal bulk motion is essential for reducing aerosol transmissibility within the room.

关键词： aerosol transmission airflow pattern horizontality COVID-19 simulation classroom ventilation

Boundedness of θ-type Calderon-Zygmund operators on non-homogeneous metric measure space

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Frontiers of Mathematics in China 2016年第1期11卷 141-153页

作者： Chol ri Zhenqiu ZHANg Department of Mathematics Kim Hyong Jik Normal University PyongYang DPR Korea school of Mathematical sciences and LPMC Nankai University Tianjin 300071 China

Let （X,d,μ） be a metric measure space satisfying both the upper doubling and the geometrically doubling conditions in the sense of Hytsnen. Under this assumption, we prove that θ-type Calderon-Zygmund operators which are bounded on L2（μ） are also bounded from L∞（μ） into RBMO（μ） and from H1,∞at（μ） into L1（μ）.

关键词： Non-homogeneous spaces θ-type Calderon-Zygmund operators,RBMO(μ) space H1,∞at(μ) space

Boundedness of Commutators of θ-Type Calderón-Zygmund Operators on Non-homogeneous Metric Measure spaces

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Chinese Annals of Mathematics,series B 2019年第4期40卷 585-598页

作者： Chol ri Zhenqiu ZHANg Department of Mathematics Kim Hyong Jik Normal UniversityPyongYangD.P.R of Korea school of Mathematical sciences and the key Laboratory of Pure Mathematics and Combinatorics Nankai UniversityTianjin 300071China

Let(X, d, μ) be a metric measure space satisfying both the upper doubling and the geometrically doubling conditions in the sense of Hyt?nen. In this paper, the authors obtain the boundedness of the commutators of θ-type Calderón-Zygmund operators with RBMO functions from L∞(μ) into RBMO(μ) and from Hat1,∞(μ) into L1(μ), *** a consequence of these results, they establish the Lp(μ) boundedness of the commutators on the non-homogeneous metric spaces.

关键词： Non-homogeneous space θ-Type Calderón-Zygmund operator Commutator RBMO(μ) space Hat1,∞(μ) space