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The black pottery coating of longshan times from Taosi Site

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Science China(Technological Sciences) 2011年第7期54卷 1708-1714页

作者： LU XiaoKe LI WeiDong LUo HongJie HE nu LI XinWei Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China Institute of Archaeology Chinese Academy of Social Sciences Beijing 100710 China

Taosi is an archaeological site in Xiangfen county, Shanxi province. It is considered as a capital city site with the rudiment of an early country in Longshan Times. In this work, the black pottery coating was found on the surface of black and grey pottery of Longshan times and confirmed by scientific studies for the first time. It filled in the blank of pottery coating study in this time period at the Yellow River Valley, as well as supplied a new study method of "black skin pottery" besides the carburization craft. In addition, according to the archaeological materials, we inferred that the wares with this pottery coating might be only used by the nobility at that time.

关键词： Taosi site pottery coating chemical composition microstructure

Adaptive contourlet-wavelet iterative shrinkage/thresholding for remote sensing image restoration

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第8期15卷 664-674页

作者： nu WEN Shi-zhi YANG Cheng-jie ZHU Sheng-cheng CUI Anhui Institute of optics and Fine mechanics Chinese Academy of Sciences Key Laboratory of optical Calibration and Characterization Chinese Academy of Sciences University of Chinese Academy of Sciences

In this paper, we present an adaptive two-step contourlet-wavelet iterative shrinkage/thresholding （TcwlST） algorithm for remote sensing image restoration. This algorithm can be used to deal with various linear inverse problems （LIPs）, including image deconvolution and reconstruction. This algorithm is a new version of the famous two-step iterative shrinkage/thresholding （TWIST） algorithm. First, we use the split Bregrnan Rudin-osher-Fatemi （RoF） model, based on a sparse dictionary, to decompose the image into cartoon and texture parts, which are represented by wavelet and contourlet, respectively. Second, we use an adaptive method to estimate the regularization parameter and the shrinkage threshold. Finally, we use a linear search method to find a step length and a fast method to accelerate convergence. Results show that our method can achieve a signal-to-noise ratio improvement （ISNR） for image restoration and high convergence speed.

关键词： Image restoration Adaptive Cartoon-texture decomposition Linear search lterative shrinkage/thresholding

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.mUHAmmAD m.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. one plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si o2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(mHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in mATHEmATICA. numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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microstructure and properties of as-cast Zr-2.5Nb-1X(X=Ru,mo,Ta and Si) alloys for biomedical application

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Rare metals 2023年第10期42卷 3497-3509页

作者： Xi-nu Tan Fei-Tao Li Yu-Shun Liu Ri-Sheng Qiu Qing Liu Electron microscopy Center College of Materials Science and EngineeringChongqing UniversityChongqing400044China International Joint Laboratory for Light Alloys(moE) College of Materials Science and EngineeringChongqing UniversityChongqing400044China TU Ilmenau Chair Materials for Electrical Engineering and ElectronicsInstitute of Materials Science and Engineering and Institute of Micro-and Nanotechnologies MacroNanoIlmenau98693Germany Department of mechanical Engineering University of ManitobaWinnipegMBR3T 5V6Canada Key Laboratory for Light-Weight materials Nanjing Tech UniversityNanjing210009China

The micro structure and properties of as-cast Zr-2.5Nb-1X(X=Ru,mo,Ta and Si) alloy are screened to explore novel biomedical zirconium alloys for magnetic resonance *** micro structure and phase transformation were characterized using X-ray diffraction(XRD),scanning electron microscope(SEm)and transmission electron microscope(TEm).Hardness test,magnetic detection and electrochemical corrosion measurements are taken to present *** results show that all alloys consist of α-Zr,β-Zr and ω-Zr.α-Zr and β-Zr mainly exist in the form of parallel and intersecting plates,and nanoscale ω-Zr is dispersed in β-Zr ***,blocky ω-Zr with needle-like α-Zr is only found in plate-free blocks of Zr-2.5Nb-1mo/Ru *** orientation relationship(oR) between α-Zr and ω-Zr follows [1120]_α//[1101]_ω and(0001)_α//([1011]_ω 011)_ω.Combining this oR with the oR between β-Zr and ω-Zr,the transformation relationship between β-Zr/ω-Zr and α-Zr is also ***-2.5Nb-1Ru alloy with high corrosion potential(-0.500 V),low corrosion rate(0.949 μm·year^(-1)) and low magnetic susceptibility(92×10^(-6)) shows great potential to be a novel biomedical implant with magnetic resonance imaging *** on the experimental results,the possible relationship among alloying elements,micro structure and properties has been established in these Zr-2.5Nb-1X alloys.

关键词： Zirconium alloy microstructure Phase transformation Electrochemical corrosion magnetic susceptibility

Search for microglia-specific peptides:advances in the discovery toolbox

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Neural Regeneration Research 2025年第2期20卷 471-472页

作者： Ivan Sarabia Kyle m.Koss Department of Surgery University of ArizonaTucsonAZUSA

Uncontrolled and chronic inflammatory states in the central nervous system(CNS)are the hallmark of neurodegenerative pathology and every injury or stroke-related *** key mediators of these neuroinflammatory states are glial cells known as microglia,the resident immune cell at the core of the inflammatory event,and astroglia,which encapsulate inflammatory insults in proteoglycan-rich scar *** gliotic scar blocks significant portions of healthy axonal networking,preventing *** most neuroinflammation is exclusively based on the responses of said microglia,their phenotypes are suggested to follow those of macrophages;m1 and m2 are opposites of pro-and ***,microglial phenotypes have been identified to be on an inflammatory spectrum encompassing developmental,homeostatic,and reparative behaviors as opposed to their ability to affect devastating cell death cascades and scar tissue formation.

关键词： inflammation pathology death

The Integrated Control-mechanism in ATm-Based Networks

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The Journal of China Universities of Posts and Telecommunications 2000年第1期7卷 20-25页

作者： GUoJun-neng CHENJi-nu Scientific Institute of Chongqing University of Posts and Telecommunications Chongqing400065P.R.China Scienti

Survivability is one of the important issues in ATm-based networks since even a single network element failure may cause a serious data loss. This paper introduces a new restoration mechanism based on multi-layer ATm survivable network management architecture. This mechanism integrates the general control and restoration control by establishing the Working VPs logical network, Backup VPs logical network and spare logical network in order to optimally utilize the network resources while maintaining the restoration requirements.

关键词： survivability ATm restoration multi-layer working-VPs backup-VPs

Analysis of multiple Annular Pressure in Gas Storage Well and High-Pressure Gas Well

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Energy Engineering 2023年第1期120卷 35-48页

作者： Lihu Cao Jinsheng Sun Bo Zhang nu Lu Yuqiang Xu School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580China Tarim oilfield Company PetroChinaKorla841000China CNPC Research Institute of Safety and Environment Technology Beijing102206China Research Institute of Petroleum Exploration&Development PetroChinaBeijing100083China

In gas storage or high-pressure gas wells,annular pressure is an unavoidable threat to safe,long-term resource *** more complex situation,however,is multiple annular pressure,which means annular pressure happens in not only one annulus but two or *** a situation brings serious challenges to the identification of well ***,few researches analyze the phenomenon of multiple annular ***,this paper studies the mechanism of multi-annular pressure to provide a foundation for its prevention and ***,the multi-annular pressure is classified according to the mechanism and field *** the failure mechanism and function of the wellbore safety barriers in the process of passage formation are ***,some suggestions are put forward for identifying and controlling multi-annular *** results show that gas storage wells and high-pressure gas wells have the conditions to generate pressure channels,which leads to the expansion of annular pressure from a single annulus to multiple *** pressure channel is composed of the tubing string,casing string,and a cement mantle,and the failures among the three have causal and hierarchical *** to the channel direction,it can be divided into two types:tubing-casing annulus to casing annulus and casing annulus to the tubing-casing annulus,of which the former is more *** measures can be considered to prevent pressure channeling,including improvement of cementing quality,revision of maximum allowable annular pressure,and suitable frequency of pressure relief.

关键词： multiple-annular pressure pressure channel generation mechanism identification and control

SPECTRA oF ComPoSITIoN GRoUPS oN THE WEIGHTED DIRICHLET SPACE oF THE UPPER HALF-PLANE

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Acta mathematica Scientia 2020年第6期40卷 1739-1752页

作者： m.o.AGWANG J.o.BoNYo Department of Pure and Applied mathematics Maseno UniversityP.O.BOX 333-40105MasenoKenya

We prove that the group of weighted composition operators induced by continuous automorphism groups of the upper half plane U is strongly continuous on the weighted Dirichlet space of U,Dα(U).Further,we investigate when they are isometries on Dα(U).In each case,we determine the semigroup properties while in the case that the induced composition group is an isometry,we apply similarity theory to determine the spectral properties of the group.

关键词： one-parameter semigroup composition operator semigroups strong continuity infinitesimal generator spectra

Simulation study on cavity growth in ductile metal materials under dynamic loading

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Frontiers of physics 2013年第4期8卷 394-404页

作者： Ai-Guo nu Guang-Cai Zhang Yang-Jun Ying Xi-Jun Yu National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009-26 Beijing 100088 China

Cavity growth in ductile metal materials under dynamic loading is investigated via the material point method. Two typical cavity effects in the region subjected to rarefaction wave are identified：（i） part of material particles flow away from the cavity in comparison to the initial loading velocity, （ii） local regions show weaker negative or even positive pressures. Neighboring cavities interact via coalescence of isobaric contours. The growth of cavity under tension shows staged behaviors. After the initial slow stage, the volume and the dimensions in both the tensile and transverse directions show linear growth rate with time until the global tensile wave arrives at the upper free surface. It is interesting that the growth rate in the transverse direction is faster than that in the tensile direction. The volume growth rate linearly increases with the initial tensile velocity. After the global tensile wave passed the cavity, both the maximum particle velocity in the tensile direction and the maximum particle velocity in the opposite direction increase logarithmically with the initial tensile speed. The shock wave reflected back from the cavity and compression wave from the free surface induce the initial behavior of interracial instabilities such as the Richtmyer-meshkov instability, which is mainly responsible for the irregularity in the morphology of deformed cavity. The local temperatures and distribution of hot spots are determined by the plastic work. Compared with the dynamical process, the heat conduction is much slower.

关键词： material point method cavity growth dynamic loading interracial instability