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Instantaneous frequency and wave mode identification in a magnetosheath using few spatial points

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Chinese Physics B 2013年第8期22卷 496-501页

作者： nathaniel E U Beloff n George n j Department of Physics Akwa Ibom State UniversityNigeria University of Sussex Brighton UK

Observational data such as those obtained from the magnetosheath in the downstream of Earth＇s bow shock have waveforms that differ from those of sinusoidal signals. In practice, they are not even aggregates of sinusoidal signals. Therefore, the frequency decomposition for the data requires technique that will account for the time-varying features of the data that will lead to deduction of physical meaning of the observations. The combination of empirical mode decompo- sition （EMD） and Hilbert transform has been used for extracting the various contributing oscillatory modes （EMDs） and the instantaneous frequency determination （Hilbert transform） of every physically meaningful mode called intrinsic mode func- tion （IMF）. The resulting instantaneous frequencies are used to determine instantaneous wave vectors. The combination of the instantaneous frequencies and wave vectors is useful in the identification of wave modes based on the characteristics of the waves. The results show that EMD-Hilbert can be more reliable than simple Hilbert transform alone.

关键词： EMD-Hilbert transform instantaneous frequency and wave vector

On Integrable Roots in Split Lie Triple Systems

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Acta Mathematica Sinica,English Series 2009年第11期25卷 1759-1774页

作者： A.j.CALDERón MARTín Departamento de Matemáticas Universidad de Cádiz

We focus on the notion of an integrable root in the framework of split Lie triple systems T with a coherent 0-root space. As a main result, it is shown that if T has all its nonzero roots integrable, then its standard embedding is a split Lie algebra having all its nonzero roots integrable. As a consequence, a local finiteness theorem for split Lie triple systems, saying that whenever all nonzero roots of T are integrable then T is locally finite, is stated. Finally, a classification theorem for split simple Lie triple systems having all its nonzero roots integrable is given.

关键词： Lie triple system root split Lie algebra classification theory

ERROR ESTIMATES FOR THE TIME DISCRETIZATIOn FOR nOnLInEAR MAXWELL'S EQUATIOnS

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journal of Computational Mathematics 2008年第5期26卷 677-688页

作者： Mavián Slodika ján Bua jr. Department of Mathematical Analysis Ghent University

This paper is devoted to the study of a nonlinear evolution eddy current model of the type δtB（H）＋ △↓× （ △↓ × H） =0 subject to homogeneous Dirichlet boundary conditions H × v = 0 and a given initial datum. Here, the magnetic properties of a soft ferromagnet are linked by a nonlinear material law described by B（H）. We apply the backward Euler method for the time discretization and we derive the error estimates in suitable function spaces. The results depend on the nonlinearity of B（H）.

关键词： Electromagnetic field nonlinear eddy current problem Time discretization,Error estimate.

Effect of Multipoint Heterogeneity on nonlinear Transformations for Geological Modeling: Porosity-Permeability Relations Revisited

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journal of China University of Geosciences 2008年第1期19卷 85-92页

作者： j A Vargas-Guzmán Saudi Aramco Dhahran 31311 KSA

An analysis of statistical expected values for transformations is performed in this study to quantify the effect of heterogeneity on spatial geological modeling and evaluations. Algebraic transformations are frequently applied to data from logging to allow for the modeling of geological properties. Transformations may be powers, products, and exponential operations which are commonly used in well-known relations （e.g., porosity-permeability transforms）. The results of this study show that correct computations must account for residual transformation terms which arise due to lack of independence among heterogeneous geological properties. In the case of an exponential porosity-permeability transform, the values may be positive. This proves that a simple exponential model back-transformed from linear regression underestimates permeability. In the case of transformations involving two or more properties, residual terms may represent the contribution of heterogeneous components which occur when properties vary together, regardless of a pair-wise linear independence. A consequence of power- and product-transform models is that regression equations within those transformations need corrections via residual cumulants. A generalization of this result is that transformations of multivariate spatial attributes require multiple-point random variable relations. This analysis provides practical solutions leading to a methodology for nonlinear modeling using correct back transformations in geology.

关键词： reservoir static model intrinsic permeability non-Gaussian nonlinear residual moment cumulant unbiased simulation parameter.

CD40 stimulation as a molecular adjuvant for cancer vaccines and other immunotherapies

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Cellular & Molecular Immunology 2022年第1期19卷 14-22页

作者： Timothy n.j.Bullock Department of Pathology University of VirginiaCharlottesvilleVAUSA

The substantial advances attained by checkpoint blockade immunotherapies have driven an expansion in the approaches used to promote T cell access to the tumor microenvironment to provide targets for checkpoint *** in any T cell response to a tumor antigen is the capacity of dendritic cells to initiate and support such ***,the rationale and early immunobiology of CD40 as a master regulator of dendritic cell activation is reviewed,with further contextualization and appreciation for the role of CD40 stimulation not only in cancer vaccines but also in other contemporary immune-oncology approaches.

关键词： CD40 vaccine CD40L T cell dendritic cell

Amorphous WO_(3-x)thin films with color characteristics tuned by the oxygen vacancies created during reactive DC sputtering

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journal of Materials Science & Technology 2021年第19期78卷 223-228页

作者： C.Guillén j.Herrero Departamento de Energia(CIEMAT) Avda.Complutense 40.28040 MadridSpain

Tungsten oxides are interesting for a variety of applications due to their versatile optoelectronic characteristics,which can be tuned changing the composition and/or the crystalline *** due to sub-bandgap absorption is often achieved by ion intercalation or doping in WO_(3):M films(with M=H^(+),Li^(+),na^(+),*** extra electrons),but a more direct way is creating charged oxygen vacancies(V_O^(+)and/or V_O~(2+))in sub-stoichiometric WO_(3-x)***,amorphous WO_(3-x)thin films are obtained by reactive DC sputtering of a pure W target,on unheated glass substrates,changing the oxygen to argon pressures *** control of intrinsic defects(oxygen vacancies and tungsten valence states)by the oxygen partial pressure allows tuning the morphology,sub-bandgap absorption and carrier density in these WO_(3-x)films,as it is proven by Raman spectroscopy,atomic force microscopy,optical spectrophotometry and Hall effect measurements.

关键词： Metal oxide Stoichiometry Optical absorption Electrical conductivity

The Mutation Game,Coxeter-Dynkin Graphs,and Generalized Root Systems

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Algebra Colloquium 2020年第1期27卷 55-78页

作者： n.j.Wildberger UnSW Sydney Sydney 2052Australia

We introduce the mutation game on a directed multigraph,which is dual to Mozes5 numbers *** new game allows us to create geometric and combinatorial structure that allows generalization of root systems to more general *** interpret Coxeter-Dynkin diagrams in this multigraph context and exhibit new geometric forms for the associated root systems.

关键词： directed graph Dynkin diagram Coxeter group mutation game root system

Mathematical modeling of nanoscale MOS capacitance in the presence of depletion and energy quantization in a poly-silicon gate

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journal of Semiconductors 2010年第11期31卷 5-8页

作者： Amit Chaudhry j.n.Roy Institute of Engineering and Technology Panjab University Solar Semiconductor Pvt.Ltd.

A model has been developed to study the effect of depletion and energy quantization at the poly-silicon /oxide interface on the behavior of a nanometer scale n-MOSFET.A model of inversion charge density,including the inversion layer quantization using the variation approach in the substrate,has also been *** the exact calculations of the polygate potential under the depletion and quantization conditions,a C-V model has been developed. All the results have been compared with the numerical models reported in existing literature and they show good agreement.

关键词： BSIM inversion layers MOS devices quantization poly-depletion poly-quantization

An enhanced close-in phase noise LC-VCO using parasitic V-nPn transistors in a CMOS process

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journal of Semiconductors 2009年第8期30卷 123-126页

作者：高佩君 Oh n j 闵昊 State Key Laboratory of ASIC & System Fudan University Department of Electronic Engineering Chungju National University

A differential LC voltage controlled oscillator （VCO） employing parasitic vertical-nPn （V-nPn） transistors as a negative gm-cell is presented to improve the close-in phase noise. The V-nPn transistors have lower flicker noise compared to MOS transistors. DC and AC characteristics of the V-nPn transistors are measured to facilitate the VCO design. The proposed VCO is implemented in a 0.18 μm CMOS RF/mixed signal process, and the measurement results show the close-in phase noise is improved by 3.5-9.1 dB from 100 Hz to 10 kHz offset compared to that of a similar CMOS VCO. The proposed VCO consumes only 0.41 mA from a 1.5 V power supply.

关键词： close-in phase noise vertical-nPn flicker noise VCO