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51.
本文利用常微分方程定性理论的方法证明了Burgers-K-dV混合型方程 ut+uux-γuxx+βuxxx=0,存在有界非平凡的行波解.当条件(3.3)成立时,该解性质类同于Burgers方程的冲击波解;当条件(3.10)式成立时,行波解具有由大到小顺次排列的一串无穷多个波峰与波谷;特别当γ→0时,最大波峰附近的行波曲线趋于K-dV方程的单孤立子解.这一事实表明此方程的解确有波粒二重性,并为用耗散与色散相互作用的观点解释湍流等物理现象提供了一定的数学依据. 相似文献
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葛渭高 《应用数学和力学(英文版)》1985,6(10):1007-1016
In this paper we prove some theorems on the existence of harmonic solutions of somesecond-order nonlinear equations under a periodic force.These theorems extend relevantresults in refs.[1]-[8]. 相似文献
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Dandan?Lian Bing?Shi Rongrong?Dai Xiaohua?JiaEmail author Xiangyang?WuEmail author 《Journal of nanoparticle research》2017,19(12):401
A kind of novel ZnSnO3/SnO2 hollow urchin nanostructure was synthesized by a facile, eco-friendly two-step liquid-phase process. The structure, morphology, and composition of samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption techniques. The results revealed that many tiny needle-like SnO2 nanowires with the average diameter of 5 nm uniformly grew on the surface of the ZnSnO3 hollow microspheres and the ZnSnO3/SnO2 hollow urchin nanostructures with different SnO2 content also were successfully prepared. In order to comprehend the evolution process of the ZnSnO3/SnO2 hollow urchin nanostructures, the possible growth mechanism of samples was illustrated via several experiments in different reaction conditions. Moreover, the gas-sensing performance of as-prepared samples was investigated. The results showed that ZnSnO3/SnO2 hollow urchin nanostructures with high response to various concentration levels of acetone enhanced selectivity, satisfying repeatability, and good long-term stability for acetone detection. Specially, the 10 wt% ZnSnO3/SnO2 hollow urchin nanostructure exhibited the best gas sensitivity (17.03 for 50 ppm acetone) may be a reliable biomarker for the diabetes patients, which could be ascribed to its large specific surface area, complete pore permeability, and increase of chemisorbed oxygen due to the doping of SnO2. 相似文献
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自适应光学系统可以实时测量并校正波前信息,但是系统中大量的噪声严重影响了系统的探测精度.自适应光学系统中一般为加性噪声,本文提出一种全新的变分处理模型去除加性噪声,该模型采用自适应非凸正则项.非凸正则项在保持图像细节上较凸正则项具有更好的效果,能更好地保持点源目标的完整性.另外,根据不同区域的噪声水平自适应地构建正则化参数,使不同区域的像素点受到不同程度的噪声抑制,可以更好地保持目标的边缘细节.在算法实现上,为了解决非凸正则项收敛性较差的缺陷,采用分裂Bregman算法及增广拉格朗日对偶算法进行计算.实验及数值仿真结果都表明,该方法能够较好地去除系统中的加性噪声,且光斑信号保存得较为完整,处理后的质心探测精度及信噪比较高. 相似文献
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Concurrent Detection of Protein Adsorption on Mixed Nanoparticles by Differential Centrifugal Sedimentation 下载免费PDF全文
Ruimin Wang Lan Chen Dexing Li Renxiao Liu Guanglu Ge 《Particle & Particle Systems Characterization》2017,34(12)
In mixtures of nanoparticles of various sizes or compositions, monitoring protein partitioning on their surfaces provides important information about particle–protein interactions during competitive adsorption. Utilizing the size‐resolving capability of differential centrifugal sedimentation, the adsorption of bovine serum albumin on multisize gold nanoparticles with diameters ranging from 20 to 100 nm or gold, silver, and silica nanoparticles with similar diameter can be concurrently observed. This method can be used to gain insight into nanoparticle–protein interactions based on analyses of curvature and relative abundance. 相似文献
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Xuefang Zhou Chaoqun Ge Yizhen Wei Guowei Yang Meihua Bi Miao Hu 《Optical and Quantum Electronics》2017,49(4):166
We have experimentally demonstrated a tunable multi-wavelength Brillouin–erbium fiber laser with over 40 GHz spacing utilizing two cascaded double Brillouin-frequency-spacing cavities. In this laser configuration, two segments of 25 km-long single-mode fibers are used as Brillouin gain medium in each ring cavity, and a segment of 8 m-long erbium-doped fiber with 980 nm pump is employed to amplify Brillouin pump (BP). At BP wavelength of 1550 nm, BP power of 8.3 dBm (6.8 mW) and the maximum 980 nm pump power of 27.78 dBm (600 mW), seven output channels with fourfold Brillouin-frequency spacing, and the tuning range of 15 nm from 1545 to 1560 nm are achieved. The proposed multi-wavelength Brillouin–erbium fiber laser has wide applications, such as in microwave signal generation and optical communications. 相似文献
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