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An Optimized Correction Procedure via Reconstruction Formulation for Broadband Wave Computation

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Communications in Computational Physics 2013年第5期13卷 1265-1291页

作者： Yi Li Z.j.Wang Department of Aerospace Engineering and CFD Center Iowa State UniversityAmesIA 50011USA

Recently,a new differential discontinuous formulation for conservation laws named the Correction Procedure via Reconstruction(CPR)is developed,which is inspired by several other discontinuous methods such as the discontinuous Galerkin(DG),the spectral volume(SV)/spectral difference(SD)*** of them can be unified under the CPR formulation,which is relatively simple to implement due to its finite-difference-like *** this paper,a different discontinuous solution space including both polynomial and Fourier basis functions on each element is employed to compute broad-band ***-parameters introduced in the Fourier bases are optimized to minimize both dispersion and dissipation errors through a wave propagation *** optimization procedure is verified with a mesh resolution *** results are presented to demonstrate the performance of the optimized CPR formulation.

关键词： CPR(correction procedure via reconstruction) hybrid discontinuous space wave propagation analysis unstructured meshes

SYNERGISTIC EFFECT OF MINERAL SURFACE CONSTITUENTS IN DEXTRIN ADSORPTION

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journal of Wuhan University of Technology(Materials Science) 1994年第1期9卷 21-34页

作者：刘奇李晔 j.S.Laskowski WUT Wuhan China

As part of a systematic research on the interaction mechanism between polysaccharides and mineral surfaces, ive extend the studies on dextrin adsorption to real minerals such as oxides and salt-type minerals, based on previous studies of model systems {surface-modified quartz ). The minerals tested include hematite, rutile, fluorite, calcite, apatite, etc. It is observed that dextrin adsorption on these minerals is strongly pH-depen-dent, with adsorption maxima appearing at pH values around the isoelec-tric points of the minerals, indicating interactions zvith surface metal hy-droxide species. X-ray photoelectron spectroscopy (XPS) measurements re-veal electronic binding energy shifts or Auger parameter changes of miner-al surface elements after dextrin adsorption , pointing to a chemical mecha-nism of interaction. Furthermore, it is observed that the reaction of miner-als with moderate amounts of fatty acids prior to dextrin addition results in an increase in dextrin adsorption, whereas excessive fatty acids do the opposite. Combined with our previous studies, it is concluded from the ex-perimental observations that although surface hydrophobic species alone do not have any effect on dextrin adsorption, they synergistically enhance the adsorption when present together with surface metallic sites.

关键词： dextrin adsorption synergistic effect mineral surjace constituents

Using Twitter Bios to Measure Changes in Self-Identity:Are Americans Defining Themselves More Politically Over Time?

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journal of Social Computing 2021年第1期2卷 1-13页

作者： Nick Rogers jason j.jones Department of Sociology Stony Brook UniversityStony BrookNY 11794USA

Are Americans weaving their political views more tightly into the fabric of their self-identity over time?If so,then we might expect partisan disagreements to continue becoming more emotional,tribal,and *** recent scholarship has speculated that this politicization of Americans’identity is occurring,but there has been little compelling attempt to quantify the phenomenon,largely because the concept of identity is notoriously difficult to *** introduce here a methodology,Longitudinal Online Profile Sampling(LOPS),which affords quantifiable insights into the way individuals amend their identity over *** this method,we analyze millions of“bios”on the microblogging site Twitter over a 4-year span,and conclude that the average American user is increasingly integrating politics into their social *** on the site are adding political words to their bios at a higher rate than any other category of words we measured,and are now more likely to describe themselves by their political affiliation than their religious *** data suggest that this is due to both cohort and individual-level effects.

关键词： identity social identity theory social media ideology political polarization Twitter

Smart Grid Wide-Area Transmission System Visualization

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Engineering 2015年第4期1卷 466-474页

作者： Thomas j.Overbye james Weber University of Illinois at Urbana-Champaign PowerWorld Corporation

The installation of vast quantities of additional new sensing and communication equipment, in conjunction with building the computing infrastructure to store and manage data gathered by this equipment, has been the fi rst step in the creation of what is generically referred to as the "smart grid" for the electric transmission system. With this enormous capital investment in equipment having been made, attention is now focused on developing methods to analyze and visualize this large data set. The most direct use of this large set of new data will be in data visualization. This paper presents a survey of some visualization techniques that have been deployed by the electric power industry for visualizing data over the past several years. These techniques include pie charts, animation, contouring, time-varying graphs, geographic-based displays, image blending, and data aggregation techniques. The paper then emphasizes a newer concept of using word-sized graphics called sparklines as an extremely eff ective method of showing large amounts of timevarying data.

关键词：数据可视化电传动系统电网智能传输广域通信设备计算基础设施

Strong emissions of blue-yellow-red regions of La and Ti modified KNaNbO_(3) ferroelectric ceramics

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journal of Advanced Ceramics 2015年第3期4卷 183-189页

作者： M.D.DURRUTHY-RODRIGUEZ M.HERNANDEZ-GARCIA j.PORTELLES j.FUENTES M.A.HERNANDEZ-LANDAVERDE M.RAMIREZ CARDONA j.M.YANEZ-LIMON Departamento de Fisica Aplicada Instituto de CiberneticaMatematica y FisicaCITMA15#551VedadoLa HabanaCP 10400Cuba Facultad de Fisica Universidad de La HabanaSan Lazaro y LVedadoLa HabanaCP 10400Cuba CINVESTAV-Unidad Queretaro IPNLibramiento Norponiente 2000Fracc.Real de JuriquillaCP 76230QueretaroMexico Centro de Investigaciones en Ciencias de la Tierra y Materiales Universidad Autonoma del Estado de HidalgoMexico

In this work,the results of the study on the optical properties of the perovskite structure ABO3 with La^(3+) substitution for ions K^(+) and Na^(+) in the A site and Ti^(4+) substitution for ion Nb^(5+) in the B site are *** ceramics were sintered at 1100℃ and 1190℃ and formed at 10 MPa and 80 *** ceramics were obtained with 94% of the theoretical *** piezoresponse force microscopy(PFM)showed needle-shaped grains with a size of 30 nm for the samples formed at 10 MPa at both sintering ***,the high temperature and high pressure used in formation reduced the energy of the band gap(Eg)from 3.36 to 3.09 *** emissions to 2.19,1.86,2.5,and 2.31 eV were obtained by exciting the samples at 325,373,457,and 500 nm,respectively;these emissions corresponded to blue-yellow-red regions of the visible spectrum.

关键词： emission spectra condense matter ferroelectric materials band structure X-ray diffraction(XRD)

Comparative study of well soaking timing(pre *** flowback)for water blockage removal from matrix-fracture interface

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Petroleum 2020年第3期6卷 286-292页

作者： Nur Wijaya james j.Sheng Bob L.Herd Department of Petroleum Engineering Texas Tech UniversityTexasUSA

Water blockage after hydraulic fracturing is one of the major challenges in shale oil recovery which affects the optimal production from the *** water blockage represents a higher water saturation near the matrixfracture interface,which decreases the hydrocarbon relative *** removal of water blockage in the field is typically carried out by soaking the well(i.e.,shut-in)after hydraulic fracturing operation is *** soaking period allows water redistribution,which decreases the water saturation near the matrix-fracture ***,previous field reports show that there is not a strong consensus on whether shut-in is beneficial in terms of production rate or ultimate oil *** to the large number of parameters involved in hydraulic fracturing and tight formations,it is challenging to select which parameter plays the dominant role in determining the shut-in ***,literature on field case studies does not frequently report the parameters which are of researchers’*** other words,the challenge of evaluating shut-in performance not only lies on the complexity of parameters and effects involved within the reservoir,but also the limited number of field case studies which report a comprehensive list of fracturing and reservoir *** paper aims to investigate the effect of well soaking timing on shut-in *** idea to investigate the shut-in timing effect is motivated by the fact that in the field,shut-in can take place either immediately after hydraulic fracturing but before the first flowback(i.e.,pre-flowback)or sometime after the first flowback(i.e.,post-flowback).The timing of shut-in is believed to influence the production performance,because it dictates how much water is allowed to imbibe from the fractures to the matrix before the extended production.A numerical model is built and validated by a successful history match with numerous data from core-flood *** previous s

关键词： Water blockage Formation damage Flowback Shut-in Desiccation

Computational and theoretical modeling of intermediate filament networks:Structure,mechanics and disease

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Acta Mechanica Sinica 2012年第4期28卷 941-950页

作者： Zhao Qin Markus j. Buehler Laboratory for Atomistic and Molecular Mechanics (LAMM) Department of Civil and Environmental Engineering 77 Massachusetts Ave. Massachusetts Institute of Technology Room 1-235 A&B Cambridge 02139 MA USA Center for Computational Engineering Massachusetts Institute of Technology 77 Massachusetts Ave. Cambridge MA 02139 USA Center for Materials Science and Engineering Massachusetts Institute of Technology77 Massachusetts Ave. Cambridge MA 02139 USA

Intermediate filaments, in addition to microtubules and actin microfilaments, are one of the three major components of the cytoskeleton in eukaryotic cells. It was discovered during the recent decades that in most cells, intermediate filament proteins play key roles to reinforce cells subjected to large-deformation, and that they participate in signal transduction, and it was proposed that their nanome- chanical properties are critical to perform those functions. However, it is still poorly understood how the nanoscopic structure, as well as the combination of chemical composition, molecular structure and interfacial properties of these protein molecules contribute to the biomechanical properties of filaments and filament networks. Here we review recent progress in computational and theoretical studies of the intermediate filaments network at various levels in the protein＇s structure. A multiple scale method is discussed, used to couple molecular modeling with atomistic detail to larger-scale material properties of the networked material. It is shown that a finer-trains-coarser method- ology as discussed here provides a useful tool in understanding the biomechanical property and disease mechanism of intermediate filaments, coupling experiment and simulation. It further allows us to improve the understanding of associated disease mechanisms and lays the foundation for engineering the mechanical properties of biomaterials.

关键词： Intermediate filament network - Multiple scale method Nanoscopic structure Mechanics Disease mechanism Molecular mechanics

Synthesis of ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base

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Chinese journal of Chemistry 1997年第4期15卷 379-384页

作者： Ding, Y Zhang, j Chen, YQ ost.queensu.ca

New ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base have been synthesized via condensation of the central intermediate 1 with various acids, esters, amides, and anhydrides in a... 详细信息

关键词： ribonucleoside analogues thio-substituted 1,3,4-triazoles heterocyclic base

Q Inversion and Comparison of Influential Factors among Three Methods: CFS, SR, and AA

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Communications in Computational Physics 2020年第6期28卷 356-371页

作者： Yinting Wu j.T.Wu School of Geological and Surveying&Mapping Engineering Chang’an UniversityXi’an 710064P.R.China School of CML Engineering&Architecture Ningbo Institute of TechnologyZhejiang UniversityNingbo 315100P.R.China

The goals of this study were to examine factors influencing Q inversion and to provide references for practical *** different methods for inverting Q values with VSP data were explored,including centroid frequency shift(CFS),spectral ratio(SR),and amplitude attenuation(AA).Comparison between the CFS and the other two methods was conducted on frequency band widths and low attenuation,wavefield components,interface interference,and thin *** from several sets of VSP modeling data indicated that the CFS method is more stable and accurate for dealing with thin and high Q *** band width,especially the presence of high frequencies,influences the inversion effect of all three *** wider the band,the better the results.Q inversion from downgoing wavefield was very similar to that of the upgoing *** CFS method had fewer outliers or skip values from the full wavefield than the other two ***,the applications to Q inversion for the set of field VSP data demonstrated that the Q curves from the CFS method coincided with the geological interpretations better than the Q curves of the other ***,inverse Q filtering shifted the frequency component from 25 Hz to 35 *** results demonstrated that the Q curve is more sensitive to geological horizons than velocity.

关键词： Q inversion centroid frequency shift amplitude attenuation spectral ratio zero-offset VSP data