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Rheological properties of a multiscale granular system during mixing of cemented paste backfill:A review

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1444-1454页

作者： Cuiping Li Xue Li Zhu’en ruan Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing100083China Shunde Innovation School of University of Science and Technology Beijing Foshan528399China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China

The technology of cemented paste backfill(CPB)is an effective method for green *** CPB,mixing is a vital process aiming to prepare a paste that meets the non-stratification,non-segregation,and non-bleeding *** a multiscale granular system,homogenization is one of the challenges in the paste-mixing *** to the high shearing,high concentration,and multiscale characteristics,paste exhibits complex rheological properties in the mixing *** overview of the mesomechanics and structural evolution is presented in this *** effects of various influencing factors on the paste's rheological properties were investigated,and the rheological models of the paste were outlined from the macroscopic and mesoscopic *** results show that the mechanical effects and structural evolution are the fundamental factors affecting the rheological properties of the *** problems and future development trends are presented to change the practice where the CPB process comes first and the theory lags.

关键词： cemented paste backfill rheology mixing process mesomechanics structural evolution

Global Behavior of a Class of Three-Dimensional Competitive Systems

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Acta Mathematica Sinica,English Series 1995年第3期11卷 316-323页

作者： ruan Jiancheng Department of Mathematical Sciences Ji'nan University Guangzhou

In this paper the global behavior of a class of three-dimensional competitive systems is investigated. The existence of semi-stable periodic orbits is proved. A generalization of the results of [1-4] is obtained.

关键词： Isomorphism Isometry ω~*-compact ω~*-converge

Platform and receptacle： Musings of modernity arising from Utzon＇s own houses

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Frontiers of Architectural Research 2016年第3期5卷 332-340页

作者： Xing ruan UNSW Australia Sydney NSW 2052 Australia

Utzon throughout his life time designed and built three houses for himself and his family. A study of these houses shows the slow development of a doubt, albeit understated, on his early architectural belief that was much celebrated in his public buildings, such as the Sydney Opera House. But Utzon is not unique in this instance. Some other modern architects too had experienced a similar change, gradual or sudden, in their attitudes towards life and the world, hence the transformation of their architecture as a consequence. This change, on the surface and as represented in architecture, is from a building that boldly embraces outside vista to that of a more internalized receptacle. But unlike Corbusier, Utzon, instead of a complete transformation, showed an inner conflict arising from this doubt, which is between the modern urge to conquer the capacious space out there and a yearning for an interior life.

关键词： Platform Vista Courtyard Receptacle Interior lire

Quantitative Characterizations of Bounded Compact Approximation Property by Semi-Fredholm Operators

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Acta Mathematica Sinica,English Series 2023年第6期39卷 1115-1128页

作者： Dong Yang CHEN Ying Bin ruan School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China School of Mathematics and Statistics Fujian Normal UniversityFuzhou 350007P.R.China

Based on a characterization of upper semi-Fredholm operators due to *** and ***,we introduce and investigate a new quantity characterizing upper semi-Fredholm *** quantity and several well-known quantities are used to characterize bounded compact approximation ***,a new quantity characterizing lower semi-Fredholm operators is introduced,investigated and used to characterize the bounded compact approximation property for dual spaces.

关键词： Bounded compact approximation property compact operators upper semi-Fredholm operators lower semi-Fredholm operators

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A microphysical investigation of different convective cells during the precipitation event with sustained high-resolution observations

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Frontiers of Earth Science 2024年第2期18卷 279-295页

作者： Ziheng HUANG Zheng ruan Debin SU State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China Key Laboratory of Atmospheric Sounding China Meteorological AdministrationChengdu 610225China

The growth and breakup processes of raindrops within a cloud influence the rain intensity and the sizes of raindrops on the *** Doppler velocity spectrum acquired by a vertically pointing radar(VPR)contains information on atmospheric turbulence and the size classification of falling *** this study,the four types of Convective Cells(CC)during precipitation events with more than 700 mm of precipitation in southern China are *** characteristics of four types of CCs correspond to the isolated convection,the early stage,the mature stage,and the decline stage of organizational convection,in that *** analysis using retrieval of vertical air motion(Vair)and raindrop evolution in clouds from Doppler velocity spectra collected by C-band VPR revealed the growth and breakup of falling raindrops with dynamic *** raindrops appear in the early stages and are accompanied by ice particles,which are impacted by the falling path᾽s *** aggregation,which is primarily related to the alternation of updraft and downdraft,accounts for the mature stage᾽s high efficiency of surface *** CCs in the decline stage originate from the shallow uplift in the weak and broad downdraft under conditions of enough water *** updraft dominates the stage of isolated *** of convective cells could be more accurately represented in model evaluations.

关键词： cloud microphysics convective systems convective cell vertically pointing radar observations Doppler velocity spectrum

Quantum K-theory and q-difference Equations

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Acta Mathematica Sinica,English Series 2022年第10期38卷 1677-1704页

作者： Yong Bin ruan Yao Xiong WEN Institute of Advanced Study for Mathematics Zhejiang UniversityHangzhou 310058P.R.China Korea Institute for Advanced Study 85 HoegiroDongdaemun-guSeoul02455Republic of Korea

This is a set of lecture notes for the first author’s lectures on the difference equations in2019 at the Institute of Advanced Study for Mathematics at Zhejiang *** focus on explicit computations and *** convergence ... 详细信息

关键词： Quantum K-theory q-difference equation

Positive divisors in symplectic geometry

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Science China Mathematics 2013年第6期56卷 1129-1144页

作者： HU JianXun ruan YongBin Department of Mathematics Sun Yat-sen University Department of Mathematics University of MichiganAnn Arbor MI 48109-1109 USA

In this paper, we first prove a vanishing theorem of relative Gromov-Witten invariant of Pl-bundle. Based on this vanishing theorem and degeneration formula, we obtain a comparison theorem between absolute and relativ... 详细信息

关键词： Gromov-Witten invariant degeneration formula blow-up

Output Waveform Analysis of an Electro-hydraulic Vibrator Controlled by the Multiple Valves

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 186-197页

作者： REN Yan ruan Jian JIA Wen'ang College of Mechanical & Electrical Engineering Wenzhou University Key Laboratory of Special Purpose Equipment and Advanced Machining Technology Ministry of Education & Zhejiang Province Zhejiang University of Technology

The existing research of the electro-hydraulic vibrator mainly focuses on system stability, working frequency width and output waveform distortion. However, this high frequency performance of the electro-hydraulic vibrator is difficult to be improved greatly due to fast insufficiently frequency response of the servo valve itself and limited compensation capability of the control structure in the vibrator system. In this paper, to realize high frequency vibration, an improved two-dimensional valve （here within defined as a 2D valve） as a main control component is adopted to the parallel connection with a servo valve to control the electro-hydraulic vibrator, Because the output waveforms of this electro-hydraulic vibrator are incapable to be verified through timely feedback as in the conventional electro-hydraulic servo system, the analysis to the output waveform becomes crucial to the design and control of the electro-hydraulic vibrator. The mathematical models of hydraulic actuation mechanism and the orifice area of the parallel valves connection are established first. And then the vibration process is divided into two sections in terms of the direction of the flow, the analytical expression of the excited waveform is solved. Based on relationships exist between working states and the control parameters the analytical results, the vibration boundary positions and the are derived. Finally an experimental system was built to validate the theoretical analysis. It is verified that this electro-hydraulic vibration system could achieve high working frequency, up to 2 000 Hz. The excited waveform is similar to the sinnsoidal waveform. And the ascent and decent slopes of the waveforms are somewhat asymmetrical. This asymmetry is not only caused by the change of the direction of the elastic force but also dependent on the bias position of the vibration. Consequentky the distortion of effective working waveform is less tha~ 10%. This electro-hydraulic vibrator controlled by t

关键词： 2D valves hydraulic multiple-valve system electro-hydraulic vibrator excited waveform

Effect of Stress-Dependent Thermal Conductivity on Thermo-Mechanical Coupling Behavior in GaN-Based Nanofilm Under Pulse Heat Source

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Acta Mechanica Solida Sinica 2021年第1期34卷 27-39页

作者： Qicong Li Xiaoya Tang Linli Zhu Haihui ruan Department of Engineering Mechanics and Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou310027China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina

The thermal properties of a nanostructured semiconductor are affected by multi-physical fields,such as stress and electromagnetic fields,causing changes in temperature and strain *** this work,the influence of stress-dependent thermal conductivity on the heat transfer behavior of a GaN-based nanofilm is *** finite element method is adopted to simulate the temperature distribution in a prestressed nanofilm under heat *** results demonstrate the effect of stress field on the thermal conductivity of GaN-based nanofilm,namely,the prestress and the thermal stress lead to a change in the heat transfer behavior in the *** the same heat source,the peak temperature of the film with stress-dependent thermal conductivity is significantly lower than that of the film with a constant thermal conductivity and the maximum temperature difference can reach 8.2 *** results could be useful for designing GaN-based semiconductor devices with higher reliability under multi-physical fields.

关键词： Multi-physical effect Stress-dependent thermal conductivity Prestress fields Heat transfer behavior GaN-based nanofilm Finite element method