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971.
奇异非线性$p-$调和方程的一类正整体解 总被引:2,自引:0,他引:2
设p>1,β≥0是常数, n是自然数, 是一个连续函数.本文研究形如的奇异非线性p-调和方程的正整体解,给出了该类方程具有无穷多个其渐近阶刚好为|x|(2n-2)(当|x|→∞时)的径向对称的正整体解的若干充分条件. 相似文献
972.
用场方法研究了相对论速调管振荡器中两个调制腔的耦合,解析地得到了两腔耦合系数与腔和波导的尺寸、间隙及两腔之间的距离等参数之间的关系。耦合系数的数值与由耦合与否腔的频率测量确定的实验结果在数量级上符合得较好。 相似文献
973.
974.
控制光和信号光频差对太赫兹光非对称解复用器性能的影响 总被引:1,自引:0,他引:1
讨论了半导体光放大器中的带间效应,及载流子热效应、谱烧孔效应、双光子吸收以及超快非线性折射等带内效应对半导体光放大器的动态特性的影响,讨论了两种情况:1)保持控制光波长不变而改变信号光频率,2)保持控制光和信号光频率相同而同时改变它们的频率下半导体光放大器的增益、相位动态特性以及太赫兹光非对称解复用器的开关窗口特性。数值结果表明,为了得到较为平坦而窄的开关窗口,控制光波长应与信号光波长相同,且其与半导体光放大器增益谱中心波长的差值应该大一些。 相似文献
975.
TiO2 electrodes are coated with NiO by DC magnetron sputtering, and their structural, optical and electrochemical performance has been investigated. X-ray diffractometry (XRD), UV-vis spectrophotometry, scanning electron microscopy (SEM), AC impedance, and linear sweep voltammetry (LSV) are used to characterize the TiO2/NiO electrodes. Their performance is evaluated with a computer controlled electrochemical workstation in combination with three conventional electrodes. The experimental results indicate that the surface modification of TiO2 electrodes with sputtered NiO reduces trap sites on TiO2 and improves the electrochemical performance of dye-sensitized solar cells (DSSCs). Sputtering NiO for 7 min, which is about 21 nm thick, on 6.5 μm thick TiO2 greatly improves the DSSC parameters, and the conversion efficiency increases from 3.21 to 4.16%. Mechanisms of the influence of the NiO coating on electrochemical performance are discussed. 相似文献
976.
Well-crystallized and stoichiometric Pb(Zr, Ti)O3 (PZT) films, typically ∼5 μm thick, with pure perovskite-type rhombohedral structures have been successfully prepared via an electrospray assisted vapour deposition (ESAVD) method. Control of the deposition temperature within a narrow range of 300-400 °C resulted in films with the most desirable phases. PZT films with close stoichiometric match with the expected composition ratio and uniform element distribution were obtained by adding the appropriate levels of excess Pb in the precursor solutions. The annealed films were uniform, dense, compact and adherent to the substrates. The dielectric constant, ?r, and loss tangent, tan δ, of the fabricated PZT films measured at 10 kHz were 442 and 0.09, respectively. The ESAVD deposited PZT films showed a remanent polarization, Pr, of 15.3 μC/cm2 and coercive field, Ec, of 86.7 kV/cm. These results demonstrate the clear potential of the ESAVD method as a promising technique for the fabrication of thick PZT films. 相似文献
977.
Weiwei Ling Huaiwu Zhang Ying He Yang Wu Kai Yang Yuanxun Li Sheng Li 《Journal of magnetism and magnetic materials》2010,322(7):819-823
The Ni-Cu-Zn ferrites with different contents of Bi4Ti3O12 ceramics (1-8 wt%) as sintering additives were prepared by the usual ceramic technology and sintered at 900 °C to adapt to the low temperature co-fired ceramic (LTCC) technology. The magnetic and dielectric properties of the ferrite can be effectively improved with the effect of an appropriate amount of Bi4Ti3O12. For all samples, the ferrite sintered with 2 wt% Bi4Ti3O12 has relatively high density (98.8%) and permeability, while the ferrite with 8 wt% Bi4Ti3O12 has relatively good dielectric properties in a wide frequency range. The influences of Bi4Ti3O12 addition on microstructure, magnetic and dielectric properties of the ferrite have been discussed. 相似文献
978.
Honglin Wu 《Linear and Multilinear Algebra》2013,61(6):609-623
For a symmetric 0–1 matrix A, we give the number of ones in A 2 when rank(A) = 1, 2, and give the maximal number of ones in A 2 when rank(A) = k (3 ≤ k ≤ n). The sufficient and necessary condition under which the maximal number is achieved is also obtained. For generic 0–1 matrices, we only study the cases of rank 1 and rank 2. 相似文献
979.
The BixSb1-x film is an important phase change material. The ultrafast dynamics of BixSb1-x film is studied by the femtosecond pump-probe technique with an 80 fs pulsed laser. Experimental results show that the reflectivity change increases with the fluence of the pump laser. The fast increase of the reflectivity occurs between 100 and 800 fs. Subsequently, the slower recovery of the reflectivity on a time scale of 1.24-18.3 ps is detected. We also found that the reflectivity change can be greatly affected by the ratio between Bi and Sb composition in BixSb1-x materials with x = 0.2 and 0.88. These experimental results should be helpful for developing new devices with ultrafast dynamics of BixSb1-x film and ultrafast optical switching. 相似文献
980.
Shi-Liang Wu Hai-Qin Zhao San-Yang Liu 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,62(3):377-397
This paper is concerned with the traveling waves for a class of delayed reaction-diffusion equations with crossing-monostability. In the previous papers, we established the existence and uniqueness of traveling waves which may not be monotone. However, the stability of such traveling waves remains open. In this paper, by means of the (technical) weighted energy method, we prove that the traveling wave is exponentially stable, when the initial perturbation around the wave is relatively small in a weighted norm. As applications, we consider the delayed diffusive Nicholson??s blowflies equation in population dynamics and Mackey?CGlass model in physiology. 相似文献