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61.
This paper expounds the escape time algorithm of constructing general Mandelbrot sets from the complex mapping z←zα+c(α<0). A series of interesting and rich families of fractal images are generated by changing a single parameter α. The fractal images consist of planetary structures with a central planet surrounded by satellite structures. The positions and sizes of the planet and satellite structures are analytically estimated. The embryonic satellite structure arising for non-integer values of α are also analysed. In the end, a few conclusions are reached.  相似文献   
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The behavior of ion-beam-induced crystallization of a buried amorphous layer created by means of MeV Si+ irradiation at 300℃ in Si(100) was studied by Rutherford backscattering and channeling technique. Sohd phase epitaxial crystallizations occurred from both the front and the back amorphous-crystalline(a/c) interfaces with the growth thickness being increased linearly with increasing dose of the annealing ion beam, Nuclear energy deposition was proved to play a dominant role in the process of ion-beam-induced crystallization. The high density of electronic excitation, which could enhance defect production near or at the a/c interface, may thus enhance the nuclearly normalized growth rate of ion-beam-induced crystallization at the front a/c interface.  相似文献   
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本文结合Pyragas的延迟反旬控制思想,提出了镇定混沌吸引子中嵌入的不稳定周期轨道的自适应延迟控制法。避免了常规自适应控制方法需要设计参圪模型或确定目标状态的麻烦,字种自适应延迟控制方法,控制器简单,实时性好,数值仿真结果验证了这种方法的有效性。  相似文献   
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A new oxide ion conductor,La_3GaMo_2O_(12),with a bulk conductivity of 2.7×10~(-2)S·cm~(-1) at 800 ℃ in air at-mosphere was prepared by the traditional solid-state reaction.The room temperature X-ray diffraction data could beindexed on a monoclinic cell with lattice parameters of a=0.5602(2) nm,b=0.3224(1) nm,c=1.5741(1) nm,β=102.555(0)°,V= 0.2775(2) nm~3 and space group Pc(7).Ac impedance measurements in various atmospheres furthersupport that it is an oxide ion conductor.This material was stable in various atmospheres with oxygen partial pres-sure p(O_2)ranging from 1.0×10~5 to 1.0×10~(-7) Pa at 800 ℃.A reversible polymorphic phase transition occurred atelevated temperatures as confirmed by the differential thermal analysis and dilatometric measurement.  相似文献   
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以纳米氧化镁为载体,采用浸渍法制备一系列过渡金属负载型催化剂.测试其对染料的降解性能后筛选出了效果最优的催化剂Ag/MgO,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、扩展X射线吸收精细结构谱(EXAFS)以及X射线吸收近边结构(XANES)等表征方法对该催化材料的结构特征、微观形...  相似文献   
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黄卓寅  李国龙  李衎  甄红宇  沈伟东  刘向东  刘旭 《物理学报》2012,61(4):48801-048801
本文介绍了一种确定聚合物太阳能电池功能层光学常数和厚度的方法. 该方法借助于特定的色散模型拟合透射率测试曲线以获得功能层光学常数和厚度值. 文中比较了Forouhi-Bloomer和Lorentz-Oscillator模型在体异质结薄膜的透射率拟合计算中的适用性, 计算了poly(3-hexylthiophene)(P3HT)/[6,6]-phenylC61-butyric acid methyl ester (PCBM)和 poly[2-methoxy-5-5(2'-ethyl-hexyloxy)-1,4-phenylenevinylene](MEH-PPV)/PCBM体异质结薄膜的光学常数和厚度. 拟合得到的曲线与实验曲线符合良好, 厚度计算的结果与台阶仪测量结果保持一致, 误差小于4%. 进一步分析得到的热退火和加入高沸点溶剂添加剂后P3HT/PCBM薄膜的光学常数和光学禁带值与相应器件伏安特性相符. 该方法适用于所有体异质结的功能层, 可用于聚合物太阳能电池的膜系优化和在线检测.  相似文献   
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We theoretically show that H atoms can be chemically adsorbed onto the surface of the Si-C heterofullerene- based nanotubes. The adsorbing energy of the H atom on Si-C heterofullerene-based nanotubes is in the range of 4.28-5.66 eV without any barrier for the H atom to approach to the Si-C heterofullerene-based nanotubes. The band-gap of Si-C heterofullerene-based nanotubes can be dramatically modified by introducing dopant states, i.e., there is a transition from semiconductor to conductor of the Si-C heterofullerene-based nanotubes induced by the adsorption of the H atom. These results actually open a way to tune electronic properties of heterofullerene-based nanotubes and thus may propose an efficient pathway for band structure engineering.  相似文献   
70.
We perform ab initio calculations on the self-assembled base-functionalized single-walled carbon nanotubes (SWNTs) which exhibit the quasi-1D ‘ladder' structure. The optimized configuration in the ab initio calculation is very similar to that obtained from molecular dynamics simulation. We also calculate the electronic structures of the self-assembled base-functionalized SWNTs that exhibit distinct difference from the single-branch base-functionalized SWNT with a localized state lying just below the Fermi level, which may result from the coupling interaction between the bases accompanied by the self-assembly behaviour.  相似文献   
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