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Effects of rotation and magnetic field on the nonlinear peristaltic flow of a second-order fluid in an asymmetric channel through a porous medium

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Chinese Physics B 2013年第7期22卷 303-313页

作者： A. M. Abd-Alla S. M. Abo-Dahab H. D. El-Shahrany Department of Mathematics Faculty of ScienceTaif University Department of Mathematics Faculty of Science Department of Mathematics Faculty of ScienceSouth Valley University

In this paper, the effects of both rotation and magnetic field of the peristaltic transport of a second-order fluid through a porous medium in a channel are studied analytically and computed numerically. The material is represented by the constitutive equations for a second-order fluid. Closed-form solutions under the consideration of long wavelength and low Reynolds number is presented. The analytical expressions for the pressure gradient, pressure rise, friction force, stream function, shear stress, and velocity are obtained in the physical domain. The effects of the non-dimensional wave amplitude, porosity, magnetic field, rotation, and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of rotation, magnetic field, and porosity. The results indicate that the effects of the non-dimensional wave amplitude, porosity, magnetic field, rotation, and the dimensionless time-mean flow are very pronounced in the phenomena.

关键词： peristaltic flow second-order fluid magnetic field porous medium

Perfect spin filtering controlled by an electric field in a bilayer graphene junction:Effect of layer-dependent exchange energy

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Chinese Physics B 2016年第7期25卷 488-496页

作者： Kitakorn Jatiyanon I-Ming Tang Bumned Soodchomshom Department of Physics Faculty of Science Kasetsart University Department of Materials science Faculty of Science Kasetsart University

Magneto transport of carriers with a spin-dependent gap in a ferromagnetic-gated bilayer of graphene is *** focus on the effect of an energy gap induced by the mismatch of the exchange fields in the top and bottom layers of an AB-stacked graphene bilayer. The interplay of the electric and exchange fields causes the electron to acquire a spindependent energy gap. We find that, only in the case of the anti-parallel configuration, the effect of a magnetic-induced gap will give rise to perfect spin filtering controlled by the electric field. The resolution of the spin filter may be enhanced by varying the bias voltage. Perfect switching of the spin polarization from ＋100% to -100% by reversing the direction of electric field is predicted. Giant magnetoresistance is predicted to be easily realized when the applied electric field is smaller than the magnetic energy gap. It should be pointed out that the perfect spin filter is due to the layer-dependent exchange energy. This work points to the potential application of bilayer graphene in spintronics.

关键词： bilayer graphene spin filter magnetoresistance spintronics

Small extrachromosomal circular DNA in amyotrophic lateral sclerosis matter

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Neural Regeneration Research 2025年第5期20卷 1411-1413页

作者： Marcos J.Arauzo-Bravo Daniela Gerovska Matthias Schwab Alexandra Kretz Computational Biology and Systems Biomedicine Biodonostia Health Research InstituteSan SebastianSpain Basque Foundation for science IKERBASQUEBilbaoSpainMax Planck Institute for Molecular BiomedicineComputational Biology and Bioinformatics GroupMünsterNorth Rhine-WestphaliaGermany Department of Cell Biology and Histology Faculty of Medicine and NursingUniversity of Basque Country(UPV/EHU)LeioaSpain Department of Neurology Jena University HospitalJenaThuringiaGermany

Comprehensive studies identify motor neuron spectrum disorders including amyotrophic lateral sclerosis(ALS)as globally rising fatal disorders with the highest prevalence in aging populations,influenced by ethnicity and ancestry(GBD 2016 Motor Neuron Disease Colla borators,2018).While~10% of diagnoses involve a family history(fALS),most cases are considered sporadic(sALS).However,population-based studies suggest that even cases without a common index mutation impart heritability(Ryan et al.,2019),indicating a crucial role of rare and as yet unknown genetic denominators.

关键词： amyotrophic sclerosis

Daily variation of radon gas and its short-lived progeny concentration near ground level and estimation of aerosol residence time

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Chinese Physics B 2016年第5期25卷 111-118页

作者： M Mohery A M Abdallah A Ali S S Baz Physics Department Faculty of Science University of Jeddah Physics Department Faculty of Science Sohag University Astronomy Department Faculty of Science King Abdulaziz University Astronomy Department Faculty of Science Cairo University Physics Department Girls Faculty of Science King Abdulaziz University

Atmospheric concentrations of radon（^（222）Rn） gas and its short-lived progenies^（218）Po,^（214）Pb, and^（214）Po were continuously monitored every four hours at the ground level in Jeddah city, Kingdom of Saudi Arabia. The measurements were performed three times every week, starting from November 2014 to October 2015. A method of electrostatic precipitation of positively charged^（218）Po and ^（214）Po by a positive voltage was applied for determining^（222）Rn gas concentration. The short-lived^（222）Rn progeny concentration was determined by using a filter holder connected with the alpha-spectrometric technique. The meteorological parameters（relative air humidity, air temperature, and wind speed） were determined during the measurements of^（222）Rn and its progeny concentrations.^（222）Rn gas as well as its short-lived progeny concentration display a daily and seasonal variation with high values in the night and early morning hours as compared to low values at noon and in the afternoon. The observed monthly atmospheric concentrations showed a seasonal trend with the highest values in the autumn/winter season and the lowest values in the spring/summer season. Moreover, and in parallel with alphaspectrometric measurements, a single filter-holder was used to collect air samples. The deposited activities of^（214）Pb and the long-lived^（222）Rn daughter ^（210）Pb on the filter were measured with the gamma spectrometric technique. The measured activity concentrations of^（214）Pb by both techniques were found to be relatively equal largely. The highest mean seasonally activity concentrations of ^（210）Pb were observed in the autumn/winter season while the lowest mean were observed in the spring/summer season. The mean residence time（MRT） of aerosol particles in the atmospheric air could be estimated from the activity ratios of ^（210）Pb/^（214）Pb.

关键词： daily variation radon progeny concentration meteorological variables

Photocatalytic activity of La-doped ZnO nanostructure materials synthesized by sonochemical method

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Rare Metals 2016年第5期35卷 390-395页

作者： Anukorn Phuruangrat Phattranit Dumrongrojthanath Oranuch Yayapao Jirapong Arin Somchai Thongtem Titipun Thongtem Department of Materials science and Technology Faculty of Science Prince of Songkla University Department of Chemistry Faculty of Science Chiang Mai University Department of Physics and Materials science Faculty of Science Chiang Mai University faculty of science Materials Science Research Center Chiang Mai University

ZnO nanostructure materials doped with different La contents were synthesized by sonochemical method. The products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）,transmission electron microscopy（TEM）, Raman spectroscopy, and Fourier transform infrared spectroscopy（FTIR）. In this research, XRD patterns of pure ZnO and La-doped ZnO are specified as hexagonal wurtzite ZnO structure with no detection of La2O3 phase. SEM and TEM characterization revealed the flower shape of pure ZnO built-up from petals of hexagonal prisms with hexagonal pyramid tips. Upon doping with La, the flower-shaped ZnO is broken into individual 1D prism-like nanorods. Photocatalytic activities of the as-synthesized products were determined by measuring the degradation of methylene blue（MB） under ultraviolet–visible（UV） light *** them, the 2.0 mol% La-doped ZnO shows better photocatalytic properties than any other products.

关键词： Nanostructure materials Sonochemical method Photocatalysis

Photoluminescence and photonic absorbance of Ce_2(MoO_4)_3 nanocrystal synthesized by microwave-hydrothermal/solvothermal method

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Rare Metals 2018年第10期37卷 868-874页

作者： Wachiraporn Maisang Anukorn Phuruangrat Somchai Thongtem Titipun Thongtem Department of Physics and Materials science Faculty of Science Chiang Mai University Department of Materials science and Technology Faculty of Science Prince of Songkla University Department of Chemistry Faculty of Science Chiang Mai University Materials science Research Center Faculty of Science Chiang Mai University

In this research, cerium （III） nitrate hexahydrate （Ce（NO3）3·6H2O） and ammonium molybdate tetrahydrate （（NH4）6Mo7O24·4H2O） with Ce3＋-to-Mo6＋ molar ratio of 2：3 were dissolved in 40 ml different solvents of deionized （DI） water, polyethylene glycol （PEG） and ethylene glycol （EG） to form different solutions which were followed by adjusting pH from the traditional values to 7.0 and 10.0 with 1 mol.L-1 sodium hydroxide （NaOH）. Subsequently, the solutions were processed by 270-W microwave-hydrother- mal/solvothermal method. Phase, morphology, vibrational modes and photonic properties were fully characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FTIR）, Raman spectrophotometry, ultraviolet-visible （UV-Vis） absorption and photoluminescence （PL） spectroscopy. The as-synthe-sized products were pure cerium molybdenum oxide （Ce2（MoO4）3） of nanoparticles clustered together as nano- plates in DI water and PEG solvents, and of spindle-like nanoparticles in EG solvent, including the presence of Ce-O-H mode and MoO4 units. The results show that direct energy gaps of the first two have the same value of 2.30 eV, and that of the last is 2.80 eV, including their blue emission at the same wavelength of 488 nm.

关键词： Ce2(MoO4)3 Microwave-hydrothermal/solvothermal method X-ray diffraction Photoluminescence Energy gap

Effect of inertia mass on the stochastic resonance driven by a multiplicative dichotomous noise

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Chinese Physics B 2012年第5期21卷 82-87页

作者：李鹏聂林如黄奇瑞孙兴修 faculty of science Kunming University of Science and Technology

A stochastic system driven by dichotomous noise and periodic signal is investigated in the under-damped *** exact expressions of output signal amplitude and signal-to-noise ratio（SNR） of the system are *** results indicate that the inertial mass greatly affects the output signal amplitude and the *** of whether the noise is symmetric or asymmetric,the inertial mass can influence the phenomenon of stochastic resonance（SR） of the system,leading to two types of resonance phenomenon：one is coherence-resonance-like of the SNR with inertial mass,the other is the SR of the SNR with noise intensity.

关键词： dichotomous noise inertial mass output signal amplitude signal-to-noise ratio

Effect of inertial mass on a linear system driven by dichotomous noise and a periodic signal

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Chinese Physics B 2011年第10期20卷 123-131页

作者：李鹏聂林如吕秀敏张启波 faculty of science Kunming University of Science and Technology

A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio （SNR） of the system are derived. By means of numerical calculation, the results indicate that （i） at some fixed noise intensities, the output signal amplitude with inertial mass exhibits the structure of a single peak and single valley, or even two peaks if the dichotomous noise is asymmetric; （ii） in the case of asymmetric dichotomous noise, the inertial mass can cause non-monotonic behaviour of the output signal amplitude with respect to noise intensity; （iii） the curve of SNR versus inertial mass displays a maximum in the case of asymmetric dichotomous noise, i.e., a resonance-like phenomenon, while it decreases monotonically in the case of symmetric dichotomous noise; （iv） if the noise is symmetric, the inertial mass can induce stochastic resonance in the system.

关键词： underdamped linear system dichotomous noise inertial mass output signal amplitude,signal-to-noise ratio

高离子电导率和均匀锂离子传输的磺酸基聚醚凝胶聚合物电解质用于高性能锂金属电池（英文）

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science China Materials 2025年

作者：胡振原刘子莹刘凯秦金鹏郭文凡凡威震张运丰 Hydrogen Energy Technology Innovation Center for Hubei Province Faculty of Material Science and Chemistry China University of Geosciences (Wuhan) School of Environmental Studies China University of Geosciences (Wuhan)

凝胶聚合物电解质基锂金属电池由于高比容量和低成本的优势,对于发展高能量密度储存设备具有重要意义.然而,传统型凝胶电解质因其锂离子传输效率较低、易产生极化现象,从而导致不可控的锂枝晶生长,最终阻碍了其大规模实际应用.本文设计...

凝胶聚合物电解质基锂金属电池由于高比容量和低成本的优势,对于发展高能量密度储存设备具有重要意义.然而,传统型凝胶电解质因其锂离子传输效率较低、易产生极化现象,从而导致不可控的锂枝晶生长,最终阻碍了其大规模实际应用.本文设计并合成出具有丰富离子传输位点的聚醚型锂单离子传导聚合物（DEBS-Li）,随后将其与聚偏氟乙烯-六氟丙烯P（VDF-HFP）基质相复合,采用静电纺丝技术制备出高传导性复合纳米纤维膜.实验发现,具有丰富磺酸基团的DEBS-Li可通过静电作用促进锂盐解离,从而加快离子迁移,赋予凝胶电解质在25℃时具有高离子电导率(～1.58×10-3S cm-1)和锂离子迁移数（0.62）.离子传输动力学的优化可大大延迟锂枝晶的成核时间,并显著抑制锂枝晶的形成.因此,采用该电解质组装成的锂对称电池在1.5 mA cm-2稳定运行250小时未发生短路,金属锂二次电池在10 C的高倍率下稳定循环500圈,容量保持率约为90%.本工作开发的新型聚醚凝胶聚合物电解质在高性能锂电池的实际应用中具有极大潜力.

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