浓差极化的介电模型——复合膜/溶液体系的数值模拟

提出了具有电导率和介电常数线性分布的介质的介电模型, 并导出了其内部电的和结构性质的参数与宏观测量的电容和电导之间定量关系的理论表达式, 以模拟复合膜中的多孔层部分的介电弛豫行为. 大量的模拟计算描述并解释了多孔层介电谱随介电常数分布、厚度等性质而变化的规律. 进一步对具有层状构造的复合膜以及复合膜和溶液相组成的多层体系的弛豫行为进行了数值模拟, 比较了三个体系(多孔层、复合膜、复合膜/液相层状体系)的介电谱, 结果揭示了介电谱对各层性质的依赖关系. 所提出的电导率和介电常数线性分布的多孔层的介电模型, 也可用于具有其他电导率、介电常数分布规律的体系.     

Hysteresis of the Magnetic Particle in a Dipolar Ising Model

Zero-temperature Monte Carlo simulations are used to investigate the hysteresis of a magnetic particle in a dipolar Ising model.The magnetic particle is described in a systemm of permanent dipoles,and the dipoles are located in a cubic lattice site.The effects of the shape and the size of the particle on the hysteresis loop at zero temperature are obtained.For strong exchange interactions,the shapes of magnetic hysteresis loops approach rectangle.For weak exchange interactions,the effects of the size and the shape of the particle on the loops are more remarkable than those of strong exchange interactions case.The slope of the hysteresis loop decreases with the increase of the ratio of the semi major axis to the semi minor axis of the ellipsoidal magnetic particle,and there is an increase of the slope of the hysteresis with the decrease of the size of the magnetic particle.The effects of the shape and size of the particle on the coercive force at zero temperature are also investigated.     

SbPS4: A novel anode for high-performance sodium-ion batteries

With the in-depth research of sodium-ion batteries（SIBs）, the development of novel sodium-ion anode material has become a top priority. In this work, tube cluster-shaped SbPS₄ was synthesized by a high-temperature solid phase reaction. Then the typical short tubular ternary thiophosphate SbPS₄ compounded with graphene oxide（SbPS₄/GO） was successfully synthesized after ultrasonication and freeze-drying. SbPS₄ shows a high theoretical specific capacity（1...     

Distinct electronic and transport properties between 1T-HfSe2 and 1T-PtSe2

In this study, we employed the first-principles calculation to investigate the structural, electronic and transport properties of 1T-HfSe₂ and 1T-PtSe₂ transition metal dichalcogenides, and further explain why they share the same 1T (octahedral) layered structure but exhibit very different electronic and transport properties. There are two underlying concepts: the degree of interlayer bond ionicity and the number of 5d valence electrons of transition metal. The high degree of Hf-Se bond ionicity not only gives rise to the indirect energy gap of HfSe₂ bulk and thin films, but also results in the weak Se-Se vdW interlayer coupling to further restrict the electron transport only within a HfSe₂ layer. On the other hand, the modulation of metallic/semiconducting property of PtSe₂ bulk and thin films can be understood by the significant vdW interlayer coupling, which induces charge redistribution of Se atom and allows electrons to transport within a PtSe₂ layer as well as cross neighboring layers. Finally, our transport calculation for 1T-HfSe₂/1T-PtSe₂ bulks and monolayers suggests the great electron transport within Hf-Se/Pt-Se layer but suppresses/allows electron from neighboring layers. The robust two-dimensional characteristic of 1T-HfSe₂ and the metal-to-semiconductor transition of 1T-PtSe₂ may provide more knowledge for future application in nanoelectronic and optoelectronic devices.     

Sequential assembly of PEDOT/BiVO4/FeOOH onto cotton fabrics for photocatalytic degradation of reactive dyes

Cellulose - This paper demonstrates that a multilayered absorbent developed using Poly(3,4-ethylenedioxythiophene) (PEDOT) modified cotton fabrics provides excellent photocatalytic degradation and...     

细粒径石蜡微胶囊相变材料的制备与性能

采用阳离子和非离子复配乳化剂,通过原位聚合制备以丙烯酸酯为壁材,石蜡为芯材的细粒径微胶囊相变材料.采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、差示扫描量热(DSC)、热重(TG)及激光粒度仪分析表征了微胶囊相变材料的化学结构、表面形貌和热性能.结果表明,乳化剂的种类和壁材单体的配比对微胶囊性能有重要的影响.当采用阳离子和非离子复配乳化剂,壁材中单体甲基丙烯酸甲酯(MMA)与丙烯酸(AA)的质量比为9∶1时,微胶囊相变材料呈球形且表面光滑紧凑,尺寸仅为0.2~0.35μm,具有良好的储热能力,相变潜热高达169 J/g;微胶囊中壁材对石蜡芯材的分解具有明显热阻滞作用,分解温度比纯石蜡提高了150℃.     

Comment on the piezopolaron bound states in semiconductors

Following the perturbation theory of Bajaj et al. the ground state energy of a bound piezopolaron is computed for ZnS, ZnSe, ZnTe and CdTe. Extending this theory to the excited states, the L.A. phonon contributions to the Lamb-shifts in these piezoelectric semiconductors are obtained. It is found that these contributions are smaller by seven to eight orders when compared to the L.O. phonon contributions.     

Study of Depolarization Field Influence on Ferroelectric Films Within Transverse Ising Model

An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-field theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg-Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.     

Near infrared fourier transform Raman spectroscopy of human artery

We report the first near IR FT-Raman spectroscopy of normal diseased human artery. In normal human aorta, two bands at 1669 cm⁻¹ and 1452 cm⁻¹ dominate the spectrum and can be assigned to protein amide I and C-H in-plane bending vibrations, respectively. Weaker bands are also observed between 1250 and 1350 cm⁻¹. Non-calcified atherosclerotic lesions with a large amount of necrotic debris below the tissue surface show a relative increase in the intensity of the 1452 cm⁻¹ band. In atherosclerotic aortas which contain calcified deposits several hundred microns below the tissue surface, a strong 961 cm⁻¹ band is observed due to the symmetric stretch of phosphate groups in the calcified salts. The results show that this method provides the capability to probe biological substituents several hundred microns below the tissue surface.