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991.
ZHOU Xin FANG JianShu LIAO XiangPing ZHU QianQuan LIU ZhiMin TANG Bin 《中国科学:物理学 力学 天文学(英文版)》2013,(9):1664-1669
The effects of different defects on optical properties and plasmon resonances properties of Au nanoshell arrays were investigated by using the finite-difference time-domain(FDTD) theory.It is found that the optical properties of the nanoshell arrays are strongly influenced by different defects.We show that when the hollow Au nanoshell arrays are placed in air,there is a wide photonic band gap(PBG) in the infrared region,but the band gap becomes narrower as we introduced different defects.Based on the distributions of electric field component E z and the total energy distribution of the electric and the magnetic field,we show that there exhibit dipoles field distributions for the plasmon mode at the long-wavelength edge of the band gap,but composite higher order modes are excited at the short-wavelength edge of the band gap.The plasmon resonant modes also can be controlled by introducing defects. 相似文献
992.
LI HaoJun TANG GuiFeng HE Feng WU Bin HU XiaoGong CHEN YanLing 《中国科学:物理学 力学 天文学(英文版)》2013,(8):1591-1597
A new strategy to realize precise absolute positioning for a single-frequency user is presented. In the presented strategy, the receiver clock and ambiguities are removed using the satelliteand epoch-differenced (SDED) algorithm. As a further development of the SDED algorithm, a regional augmentation network is used to generate the SDED atmospheric delays at the user. The weakened mathematic property due to the epoch-differenced operation is improved by adding the generated atmospheric delays and applying the robust estimation. To test the new approach, the 24-h data at 5 Continuous Operation Reference Station (CORS) stations in Shanghai is processed. The results show a more than 96% success rate, defined as the case where three directions achieve the desired positioning accuracy of 10 cm, when the observation is longer than 20 min. The 20-min static results show that the new method can reach an accuracy of 3.42, 4.76 and 9.26 cm in the North, East and Up directions, respectively. An experiment was carried out to assess the kinematic positioning. The results show that the kinematic positioning accuracy is 4.11, 5.31 and 4.05 cm in the north-south, east-west and height directions,respectively. 相似文献
993.
在高温钼丝炉内向16Mn钢中加入不同含量的铈进行脱氧,分析了钢中夹杂物和组织的变化,并探讨了含铈夹杂物诱发晶内铁素体形核的机制.结果表明:随钢中铈含量的增加,夹杂物依次转变为CeAlO3,Ce2O2S和Ce2S3.经铈处理后,钢液在1873 K时保温300 s,夹杂物最为细小弥散.钢中晶内铁素体随铈含量的增加而增加,但最佳的铈含量约为0.032%(质量分数).钢中Ce2O2S和Ce2S3夹杂与α-Fe相之间的错配度分别只有1.2%和0.5%,均可作为IGF非常有效的形核核心,促进其形成. 相似文献
994.
靛蓝胭脂红-高碘酸钾-草酸钠催化光度法测定钢中微量钒 总被引:5,自引:0,他引:5
研究了在1 mol/L磷酸介质中,钒(V)对KIO4氧化靛蓝胭脂红褪色反应的催化作用及草酸钠的活化作用,建立了一种测定钒的方法。无草酸钠时该体系为准零级反应,表观活化能为76.7 kJ/mol,在22℃时钒量在0~5mg/L范围内与?A呈线性,检出限为0.1 mg/L。在草酸钠存在下则为准一级反应,表观活化能为60.1 kJ/mol,钒量在0~mg/L范围内与1g(A0/A)呈线性,检出限为0.02mg/L。提高介质酸度,可显著降低反应温度。在NaF及尿素存在下,大多数常见离子无干扰。本法简便快速,选择性和灵敏度较高,用于钢中微量钒的直接测定,结果满意。 相似文献
995.
In this paper, a unified algorithm is proposed for solving a class of convex separable nonlinear knapsack problems, which are characterized by positive marginal cost (PMC) and increasing marginal loss–cost ratio (IMLCR). By taking advantage of these two characteristics, the proposed algorithm is applicable to the problem with equality or inequality constraints. In contrast to the methods based on Karush–Kuhn–Tucker (KKT) conditions, our approach has linear computation complexity. Numerical results are reported to demonstrate the efficacy of the proposed algorithm for different problems. 相似文献
996.
997.
Guangfeng Wang Aixia Gu Wen Wang Yan Wei Jingjing Wu Guozhong Wang Xiaojun Zhang Bin Fang 《Electrochemistry communications》2009,11(3):631-634
This communication reports on a novel amperometric hydrazine sensor of CuO nanoarray based on a Cu substrate. Copper oxide nanoarray was directly grown on Cu substrates using a one-step facile hydrothermal method and was characterized using scanning electron microscopy and X-ray powder diffraction. The electrochemical study has shown that the CuO nanoarray exhibits higher catalytic effect on the hydrazine than the normal CuO nanoparticles. This may be attributed to the special structure of the nanomaterials esp. the substrate of the electric Cu. And the amperometric response showed that the CuO nanoarray modified glassy carbon electrode has a low detection and a high sensitivity for hydrazine. 相似文献
998.
JuPing Yang QiDi Zhao Bin Zhou HuaGang Ni XinPing Wang ZhiQuan Shen 《中国科学B辑(英文版)》2009,52(12):2295-2306
Most research on copolymers with fluorinated monomers has focused on the relationship between fluorinated monomer content
and the corresponding surface structure. However, the influence of the non-fluorinated block on the surface structure of the
copolymer film is unknown. Various molecular weight poly(butyl methacrylates) (PBMA) end-capped with 2-perfluorooctylethyl
methacrylate (FMA) units (PBMA-ec-FMA) have been synthesized by atom transfer radical polymerization (ATRP). The effect of the PBMA block length on the surface
structure and properties of the polymers both in the solid state and in solution was investigated using various techniques.
X-ray photoelectron spectroscopy (XPS), sum frequency generation (SFG) vibrational spectroscopy and X-ray diffraction (XRD)
analyses indicated that longer PBMA blocks enhanced both the enrichment of the fluorinated moieties and the order of the packing
orientation of the perfluoroalkyl side chains on the surface. This enhancement was attributed mainly to the molecular aggregate
structure of the end-capped polymers with long PBMA blocks in the solution and to the interfacial structure at the air/liquid
interface, which favors the -(CF2)7CF3 moieties self-assembling on the polymer surface during film formation. This observation suggests that the polyacrylate block
structure in fluorinated diblock copolymers, in addition to the fluorinated monomer content, plays an important role in structure
formation on the solid surface. 相似文献
999.
本文研究了带有Radon-Nikodym导数的算子值自由Fisher信息量.利用模框架理论,得到了一个半圆元和一个子代数之间的合并自由关系,推广了D.Voiculescu等人的工作. 相似文献
1000.
The uniqueness of meromoRphic functions that share four values are investigated, some results are obtained to show that if two nonconstant entire functions share three finite values IM, then the functions necessarily share all three values CM. 相似文献