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Multifractal Detrended Fluctuation Analysis of Interevent Time Series in a Modified OFC Model

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Communications in Theoretical Physics 2013年第1期59卷 1-6页

作者：林敏颜双喜赵钢王刚 Department of Mathematics Ocean University of China College of civil Aviation Nanjing University of Aeronautics and Astronautics Faculty of transportation engineering of Huaiyin Institute of Technology Key Laboratory of Data Analysis and Applications(LDAA) First Institute of OceanographyState Oceanic Administration

We use multifractal detrended fluctuation analysis （MF-DFA） method to investigate the multifractal behavior of the interevent time series in a modified Olami-Feder-Christensen （OFC） earthquake model on assortative scale-free networks. We determine generalized Hurst exponent and singularity spectrum and find that these fluctuations have multifraetal nature. Comparing the MF-DFA results for the original interevent time series with those for shuffled and surrogate series, we conclude that the origin of multifractality is due to both the broadness of probability density function and long-range correlation.

关键词： multifractal detrended fluctuation analysis avalanche correlations

Effect of asphalt thin beams mixed with three nominal maximum aggregate sizes in the bending beam rheometer on the prediction of thermal properties of bituminous material

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Frontiers of Structural and civil engineering 2017年第1期11卷 1-7页

作者： Chun-Hsing HO Maria Francisca Martinez GONZALEZ Cristina Pilar Martin LINARES Department of civil engineering Construction Management and Environmental Engineering Northern Arizona UniversityFlagstaff Arizona 86001 USA

The objective of this research is to evaluate an impact of asphalt mixture beams with varying sizes of aggregate in the Bending Beam Rheometer （BBR） for testing/predicting thermal cracking properties of asphalt pavements. The BBR test has following benefits： the equipment is cheaper, it uses smaller specimens, faster conditioning, easier availability for quality control, easier to manage, etc. However some concerns have been raised： some consider that the size of the aggregate may affect the test＇s results; the other concern is that such small beams cannot represent the whole properties of the asphalt pavement. To address these criticisms, imaging techniques, statistical analysis, and viscoelastic modeling are used. Asphalt thin beams prepared with three different nominal maximum aggregate size （NMAS）（12.5mm, 9.5 mm, and 4.75 mm） were tested at three different temperatures （-18℃, -24℃, and -30℃）. Based on results from statistical analyses and viscoelasticity, the ratio of asphalt binders and voids and stiffness differences among the three NMAS specimens are not significant, meaning that the impact of asphalt thin beams prepared with the three NMAS on the prediction of thermal cracking is minimal and can be neglected.

关键词： bending beam rheometer thin beams thermal cracking

Phase transformation in suspension roasting of oolitic hematite ore

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Journal of Central South University 2015年第12期22卷 4560-4565页

作者：李艳军王儒韩跃新魏新超 School of Resources and civil engineering Northeastern University College of engineering The State University of New York Polytechnic Institute

Suspension roasting followed by magnetic separation is a promising method to upgrade oolitic hematite *** oolitic hematite ore was roasted using suspension roasting technology at different *** phase transformation for iron minerals was investigated by XRD and Mossbauer spectrum,and the characteristics of roasted product were analyzed by VSM and *** indicate that the magnetic concentrate is of 58.73% Fe with iron recovery of 83.96% at 650 °*** hematite is rapidly transformed into magnetite during the roasting with transformation ratio of 92.75% at 650 °*** temperature has a significant influence on the phase transformation of hematite to *** transformation ratio increases with increased *** roasting,the magnetic susceptibility is significantly improved,while iron ore microstructure is not altered significantly.

关键词： oolitic hematite ore suspension roasting Mossbauer spectrum magnetic property phase transformation

Formation of the Tibetan Plateau during the India-Eurasia Convergence:Insight from 3-D Multi-Terrane Thermomechanical Modeling

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Journal of Earth Science 2024年第1期35卷 112-130页

作者： Jile Chen Peimin Zhu Yuefeng Yuan Guifan Chen School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China Geothermal engineering Research Center Three Gorges Geotechnical Consultants Co.Ltd.Wuhan 430074China

Various models exist to explain the formation of the Tibetan Plateau,including“tectonic escape”,“pure shear thickening”,“convective removal of the lithospheric mantle”,and“lower crustal flow”*** first two models are primarily constructed on pure mechanical models but are unable to reasonably explain the tension and shear phenomena inside the *** latter two are rheological dynamic models based on deep geophysical ***,the spatial range of the lower crustal flow and its role in the plateau formation/uplift remain *** multi-terrane viscoplastic thermomechanical models were constructed to simulate the uplift and lithospheric structure change of the Tibetan Plateau during the post-collision stage(since 35 Ma)under the convergence of the Indian *** show that the plateau's formation begins with crustal thickening,blocked by strong terranes at the northern plateau,and expanded laterally to the *** lithosphere thickens gradually and experiences delamination at its base,elevating temperature within the crust and forming partial melting layers in the central *** convergence persists on the southern side,the northern plateau's lithosphere bends downward and undergoes delamination,further heating the crust and promoting the northward and eastward flow of partial melting layers,leading to secondary uplift around the plateau.

关键词： 3-D thermomechanical modeling Tibetan Plateau plateau uplift crustal flow

Traffic dynamics considering packet loss in finite buffer networks

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Chinese Physics B 2019年第4期28卷 433-438页

作者： Jie Chen Jin-Yong Chen Ming Li Mao-Bin Hu School of engineering Science University of Science and Technology of China civil Architectural and Environmental engineering University of Texas at Austin

In real complex systems, the limited storage capacity of physical devices often results in the loss of data. We study the effect of buffer size on packet loss threshold in scale-free networks. A new order parameter is proposed to characterize the packet loss threshold. Our results show that the packet loss threshold can be optimized with a relative small buffer size. Meanwhile, a large buffer size will increase the travel time. Furthermore, we propose a Buffered-Shortest-Path-First(BSPF) queuing strategy. Compared to the traditional First-In-First-Out(FIFO) strategy, BSPF can not only increase the packet loss threshold but can also significantly decrease the travel length and travel time in both identical and heterogeneous node capacity cases. Our study will help to improve the traffic performance in finite buffer networks.

关键词： finite buffer networks loss threshold queuing strategy

Ferrofluid measurements of bottom velocities and shear stresses

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Journal of Hydrodynamics 2015年第1期27卷 150-158页

作者： MUSUMECI Rosaria E. MARLETTA Vincenzo ANDò Bruno BAGLIO Salvatore FOTI Enrico Department of civil engineering and Architecture University of Catania Department of Electric Electronic and Computer Science Engineering University of Catania

A novel direct measurement strategy of bottom velocities and shear stresses based on the use of ferrofluids is presented. Such a strategy overcomes some of the limits of state-of-the-art instruments. A preliminary experimental campaign has been carried out in the presence of currents in steady flow conditions in order to test the effects of ferrofluid quantity and of the controlling permanent magnetic force. An alternating current （AC） circuit and a direct current （DC） conditioning circuit have been tested. For velocities larger than 0.05 m/s, the near-bottom velocity-output voltage calibration curve has a monotone parabolic shape. The sensitivity of the instrument is increased by a factor of 30 when the DC circuit is used.

关键词： magnetofluids Rosensweig effect flow resistances bed shear stresses bottom velocities

Influence of Structure Plane Size on Seismic Response of Soil-Structure Interaction

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Transactions of Tianjin University 2013年第5期19卷 345-350页

作者：姜忻良张亚楠 School of civil engineering Tianjin University Key Laboratory of Coastal civil engineering Structure and Safety (Tianjin University) Ministry of Education

The influence of the change of structure plane size on seismic response was studied for a soil-structure interaction *** on the finite element method,a soil-structure interaction calculation model was established to analyze the seismic response by changing the structure plane size and choosing different earthquake waves for different soil *** results show that when the natural periods of vibration for different structure plane sizes are close,under the same earthquake wave,the total displacement on the top layer of the structure and the foundation rotation displacement decrease with the increase of structure plane size,and the proportion of superstructure elastic selfdeformation displacement to the total displacement increases with the increase of structure plane *** for different types of sites and seismic waves,under the horizontal and vertical seismic waves,the seismic responses of different plane sizes have a similar change rule.

关键词： soil-structure interaction finite element analysis structure plane size seismic response time historyanalysis

Process mineralogy and characteristic associations of iron and phosphorus-based minerals on oolitic hematite

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Journal of Central South University 2017年第9期24卷 1959-1967页

作者：罗立群张汉泉 School of Resources and Environmental engineering Wuhan University of Technology School of Resources and civil engineering Wuhan Institute of Technology

The chemical compositions,mineralogical characteristics,as well as dissemination of iron-and phosphorus-based minerals were studied for the E’xi oolitic hematite from western Hubei Province in China by using chemical analysis,optical microscope,electron probe micro-analyzer(EPMA)and energy dispersive spectroscopy(EDS).It is found that this kind of oolitic hematite ore contains 47.71%TFe,10.96%SiO_2,as well as 0.874%P,with hematite as the dominant Fe-bearing minerals,and quartz,chamosite,illite and cellophane as main gangue *** microscope examination showed that the ore has an oolitic structure,with some ooids principally formed by a series of concentric layers of hematite collophanite around nucleus that is hematite in the association with *** on the EPMA and EDS analysis,it can be known that some ooids are primarily composed of hematite and *** separation can be achieved through fine grinding for those collophanite laminae with a higher P ***,the dissemination of two minerals at the interface will result in the difficulty in effective ***,some ooids are made of chamosite with some nucleus formed of quartz,which is principally finely disseminated with *** view of the close association and dissemination of iron-and phosphorus-based minerals in the ooids,it is found that the process of stage-grindings and stage-separations can be adopted to effectively increase the iron recovery and decrease the P content in the concentrate to some extent.

关键词： oolitic hematite process mineralogy dissemination of iron- and phosphorus-based minerals electron probe micro-analyzer(EPMA) energy dispersive spectroscopy (EDS)

Experimental investigations of granular shape effects on the generation of electrostatic charge

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Particuology 2014年第4期12卷 82-89页

作者： Jun Yao Jiejie Wu Yanlin Zhao Eldin Wee Chuan Lim Peigen Cao Fang Zhou Chi-Hwa Wang Ning Li School of Energy Research Xiamen University College of Mechanical & transportation engineering China University of Petroleum Department of Chemical and Biomolecular engineering National University of Singapore4 Engineering Drive 4Singapore 117576Singapore

In solid processing systems, electrostatic problems are commonly observed for granules of various shapes. However, a complete understanding of the basic dependence of electrostatic charge generation on particle shape has yet to be established. This observation motivated the present study on examining the effect of granular shape on electrostatics. In this study, polyvinyl chloride （PVC） granules （diameter 1.1-4.1 ram, in the shape of a triangle or trapezium） were first discharged to remove any residual charges and sub- sequently their electrostatic charging characteristics were studied by allowing a granule to slide along a pipe wall. Several factors such as granular front-facing angle, length-ratio, sliding area, sliding orienta- tion, sliding times, and relative humidity were considered when studying their effects on the electrostatic charging of granules. It was found that triangular granules with smaller front-facing angles tended to generate more electrostatic charge. The amount of electrostatic charge increased with granular length- ratio and sliding area but decreased with humidity. In addition, granular sliding in the orientation of the front-facing angle （for triangular granules） or the short side （for trapezoidal granules） generated more electrostatic charge than that in the orientation of the long side. For both granule shapes, the elec- trostatic charge increased with granular sliding times and reached a saturated state after around 8-9 sliding movements. The saturated electrostatic charge increased with either granular length ratio or sliding area.

关键词： Granule Electrostatic charge Shape Triangle Trapezium