Structures,microstructures, physical and chemical properties of different rice grains

Herein, we demonstrated a well-rounded exploration of the universal structures, microstructures and physical properties of different rice grains. We show that these rice grains are nanocrystalline in nature, have the standard pattern of type A rice crystalline, and can be attributed to the hexagonal crystal structure with space group of P6. These rice grains have uneven surfaces, clusters of the granules, or schistose structure. Carbon, nitrogen and oxygen elements are presented in the rice grains. No significant difference is observed in FTIR spectra in these rice grains, indicating the fundamental chemical structures of these rice grains are analogical. Their microstructural and physical properties were investigated in detail. Moreover, chemical properties (e.g. thermal stability) of the rice grains were explored. This research provides an in-depth understanding on the physical and structural properties on the atomic and molecular level, as well as guidance for food and industry applications.     

Insulator, semiclassical oscillations and quantum Hall liquids at low magnetic fields

Magneto-transport measurements are performed on two-dimensional GaAs electron systems to probe the quantum Hall (QH) effect at low magnetic fields. Oscillations following the Shubnikov-de Haas (SdH) formula are observed in the transition from the insulator to QH liquid when the observed almost temperature-independent Hall slope indicates insignificant interaction correction. Our study shows that the existence of SdH oscillations in such a transition can be understood based on the non-interacting model.     

Electrochemical properties of rutile TiO2 nanorods as anode material for lithium-ion batteries

In this paper, we synthesized rutile TiO₂ nanorods by hydrolysis of TiCl₄ ethanolic solution in water at 50?°C. Scanning electron microscopy and transmission electron microscopy images show that the as-prepared sample was consisted of nanoflowers of about 500?nm in sizes, and each petal of nanoflowers was assembled by several nanorods. We tested the electrochemical properties of the rutile TiO₂ nanorods as an anode material for lithium-ion batteries. The rutile TiO₂ nanorods exhibited a large initial discharge capacity of 223?mA?h?g^?1, and the stabilized capacity was as high as 170?mA?h?g^?1 after 100 cycles. These improved electrochemical performances may be attributed to the shorter diffusion length for both the electron and Li⁺, and the large electrode?Celectrolyte contact area offered by the nanorods with a large specific surface area, which facilitated the lithium ions insertion and extraction.     

A novel 1 × 2 optical power splitter with PBG structures on SOI substrate

A novel 1 × 2 optical power splitter in size of 8.0 μm × 4.2 μm is presented in this paper, by using photonic bandgap (PBG) structures on silicon-on-insulator (SOI) substrate. The splitting ratio can be adjusted by changing the air hole position to get wide tuning range. The design is examined by the commercial finite-difference-time-domain (FDTD) software for various splitting ratios. Some approximated formulas are obtained through curve-fitting to facilitate design process.     

Second-harmonic generation in graded metallic films

We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly and further numerically demonstrate that graded metallic films can serve as a novel optical material for producing a broad structure in both the linear and the SHG response and an enhancement in the SHG signal.     

不同线宽结构杂散光Kirk模型分析

采用Kirk测量法的杂散光模型研究了杂散光在不同线宽结构上杂散光的光强变化,通过图像对比度分析了杂散光对不同线宽结构的影响。基于Matlab软件仿真分析表明:线宽一定时,线条越稀疏,图像对比度越低,杂散光对成像图形分辨力的影响越大;线条线间比一定时,线宽尺寸越小,图像对比度越低,杂散光对成像图形分辨力的影响也越大。所以杂散光对线宽较小并且线条稀疏空间结构所成的图形造成的影响较大。光刻; Kirk测量法; 杂散光; 点扩散函数; 图像对比度     

改革物理实验教学,培养学生创新能力

改革传统的物理实验教学内容,增加综合性、设计性、障碍性实验,开放实验室,培养学生的创新能力。     

THERMAL CREEP FLOW IN THE RAREFIED GAS

The usual heat flow moves along the direction from high temperature place to the low one, as often observed in the daily life. However, when the gas is very rarefied, the gas may move along a different way, that is, the so-called thermal creep flow moves along the direction from the low temperature place to the high one. In this note, we will survey our recent mathematical works on this topic, mainly based on [27] and [25].     

Influence of interface roughness on reflectivity of tungsten/boron-carbide multilayers with variable hi-layer number by X-ray reflection and diffuse scattering

from layer to layer during multilayer growing. The variation of the reflectivity and interface roughness with bi-layer number is accurately explained by the presented real-structure model.     

Facile fabrication of novel cyclomatrix-type polyphosphazene nanotubes with active hydroxyl groups via an in situ template approach

Novel polyphosphazene nanotubes with active hydroxyl groups were fabricated via an in situ template approach under ultrasonic irradiation. SEM and TEM results indicated that the nanotubes were uniform with length of several micrometers, inner diameter of ca. 20 nm and outer diameter of 60-80 nm. FTIR spectra revealed that the content of the hydroxyl groups on the nanotube surface was dependent on the feed ratio of hexachlorocyclotriphosphazene (HCCP) to 4,4′-sulfonyldiphenol. The successful esterification of polymer nanotubes with benzoxy chloride demonstrated the high reactivity of the hydroxyl groups. The method employed here might provide a simple and effective way to prepare functional nanotubes used for biological applications.