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101.
102.
本文提出一种利用正、赝再现像,将物体的正、反两面信息复合在一起的全息术.在一张全息干板片上,可以同时看到物体的两面,增强立体效果和艺术感.文中介绍了原理、方法和结果. 相似文献
103.
Lian-Hua Fu Yan-Yan Dong Ming-Guo Ma Shu-Ming Li Run-Cang Sun 《Ultrasonics sonochemistry》2013,20(3):839-845
The purposes of this article were to investigate the influences of synthesis strategy on the CaCO3 crystals on the cellulose substrate. In this study, CaCO3 crystals were synthesized using cellulose as matrix by the microwave-assisted method and ultrasound agitation method, respectively. The CaCO3 crystals on the cellulose substrate were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Experimental results demonstrated that the synthesis strategy had a dramatically influences on the phase, microstructure, morphology, thermal stability, and biological activity of the CaCO3 crystals. The pure phase of vaterite spheres with the diameter of about 320–600 nm were obtained by ultrasound agitation method, meanwhile, the mixed phases of calcite and vaterite with the diameter of about 0.82–1.24 μm were observed by microwave-assisted method. In view of experimental results, one can conclude that the ultrasound agitation method do more favors to the synthesis of CaCO3 crystals with uniform morphology and size, compared with microwave-assisted method. Furthermore, cytotoxicity experiments indicated that the CaCO3 crystals on the cellulose substrate had good biocompatibility and could be a candidate for the biomedical applications. 相似文献
104.
采用密度泛函(DFT)中的B3LYP方法,选择CEP-31g基组,优化并得到了MgnLa(n=2- 6)小团簇的基态平衡结构,计算出了掺杂团簇的基态结构的平均键长、对称性、费米能级、能级间隙、束缚能、总能的二阶差分.结果表明,随着团簇原子数的增加,La原子更容易趋于团簇表面位置. 与未掺杂Mg团簇相比,La原子多采用取代其稳定基态结构的一个Mg原子形成掺杂团簇的稳定结构. 从有限的结果看,其中 Mg3La和 Mg6La的结构更为稳定. 相似文献
105.
Fu Xianlong Zhou Lei Cao Yueju 《Annals of Differential Equations》2005,21(3):275-278
In this paper, we establish a criterion of unformly asymptotic stability for finite delay difference systems in terms of two measures by employing Lyapunov functionals method. 相似文献
106.
107.
We propose a line search exact penalty method with bi-object strategy for nonlinear semidefinite programming. At each iteration, we solve a linear semidefinite programming to test whether the linearized constraints are consistent or not. The search direction is generated by a piecewise quadratic-linear model of the exact penalty function. The penalty parameter is only related to the information of the current iterate point. The line search strategy is a penalty-free one. Global and local converg... 相似文献
108.
A gold nanoparticles/monolithic mesoporous silica assembly was synthesized by ultrasonic irradiation of monolithic porous silica presoaked with precursor solution. Subsequent exposure to ambient air (ageing) and then drying at 120°C induce a new optical absorption peak around 470?nm (falling into the range from 460 to 475?nm) which is stable at room temperature, in addition to the normal surface plasmon resonance (SPR) of Au nanoparticles. Further drying results in the decline and disappearance of this peak, accompanied by increase of the normal SPR. If the sample, in which the new peak has disappeared due to long drying at 120°C, is exposed to the ambience once more, this peak will appear again after subsequent drying at 120°C, showing reversibility. Further experiments indicate that ambient ageing for a certain time plays a crucial role in the appearance of the new peak after subsequent drying at 120°C. Increased ageing time increases this peak. In addition, the ambient relative humidity and temperature during exposure are also important to the appearance of this peak. This peak may be associated with Au clusters with a size less than 1.5?nm. Based on the porous structure of the assembly and hydrophilicity of its pore wall, a nanodroplet formation and evaporation model is presented which can well explain all evolution behaviours of this peak. The model predicts the existence of the peak at 470?nm in the Au/silica assembly prepared by methods other than ultrasonic irradiation, which has also been confirmed by further experiments. 相似文献
109.
Fu Y.H. Smeets R.P.P. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1989,17(5):727-729
The authors present the results of DC vacuum arc lifetime and voltage measurements for contacts with different surface microstructures. This was realized by treating the contact surface with emery paper of varying roughness. The contact surface microstructure was found to have a large effect on the DC arc lifetime (several tens of times difference at the most) and arc voltage (30% difference at the most). The mechanism of the surface microstructure effect on DC arc stability was analyzed and is explained preliminarily. The rougher the contact surface is, the longer the arc lifetime and the more stable. The arc itself has a tendency to condition the surface in a way that is unfavorable for a sustained arc lifetime. The crater size for a rough surface is smaller than for a smooth one. The rougher the contact is, the lower the arc voltage (both DC and HF components). The arc erosion has a tendency to increase the arc voltage. It is probable that type I cathode spots (fast motion, small crater size) correspond not only to the surface contamination, but also to the surface roughness 相似文献
110.
基于CH柱形靶压缩实验的时间分幅诊断需求,研制了4.75 keV能点四通道Kirkpatrick-Baez(KB)显微镜。进行了四通道KB系统的光学设计、像质模拟和分析。采用支撑锥芯的方式解决了四通道KB物镜的集成装配问题,并通过4.75 keV+8 keV双能点多层膜完成了实验室内的KB系统装调。该套系统在神光Ⅱ装置成功进行了像质考核实验,获得了高分辨的四象限网格图像,成像间距符合设计要求,具备了开展时间分幅惯性约束聚变物理实验的条件。 相似文献