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231.
We report a model for the fractal dimension D8 of rough surfaces based on the fractal distribution of roughness elements on surfaces and the fractal character of surface profiles. The proposed model for the fractal dimension Ds is expressed as a function of the fractaJ dimensions D for conic roughness diameter/height and Dp for surface profile, maximum roughness base diameter λmax, the ratio β of conic roughness height to its base radius as well as the ratio λmin/λmasx of the minimum to the maximal base diameter. 相似文献
232.
Acylthiourea derivatives are well known for a wide range of biological activities likebactericidal, fungicidal, herbicidal, insecticidal action and regulating activity for plantgroWth"'. In recent years, substituted phenoxyacetic acid derivatives have beenreported as highly efficient herbicides4. In this paper. a series of substitutedphenoxyacetyl thiourea containing substituted pyrimidine ring sa~so were synthesizedand tested for their biological activities. All of them are new compounds and… 相似文献
233.
We propose a simple scheme to generate two-mode entangled coherent state in two separated cavities and realize the entanglement
reciprocation between the superconducting charge qubits and continuous-variable system. By measuring the state of charge qubits,
we find that the entanglement of two charge qubits, which are initially prepared in the maximally entangled state, can be
transferred to the two-cavity field, and at this time the two-cavity field is in the entangled coherent state. We also find
that the entanglement can be retrieved back to the two charge qubits after measuring the state of the two-cavity field.
相似文献
234.
用硫代巴比妥酸反应分析了博莱霉素 A5 ( B L M A5 )对 D N A 的断裂作用在 Fe2+ 和 O2存在下, B L M A5能导致 D N A 链断裂研究了一些因素对 B L M A5 催化 D N A 断链反应的影响,设计并建立了 B L M A5 切割 D N A 反应的定量测定方法,并测得 Km 约为153 μm ol· L- 1, Vm ax 约为0046 A532nm Unit·s- 1 相似文献
235.
用电沉积方法得到了不同浓度硫酸锌电解液的分形凝聚图像;进行图像处理,得到了其分形维数与浓度的关系曲线;用粒子扩散限制凝聚模型解释了此关系 相似文献
236.
在200 keV重离子加速器上,用120—360 keV的H,N,Ar和Mo离子注入C60薄膜.对注入后薄膜的拉曼谱进行了分析.结果表明,不同离子注入C60薄膜后,C60的1469 cm-1特征峰随注入剂量的增加均呈指数式下降,同时在1300—1700 cm-1范围出现非晶碳峰,并逐渐增强,最终完全非晶化.而且1469 cm-1拉曼峰的强度及C60薄膜完全非晶化所对应的剂量与注入离子的种类和能量有关.进一步的分析表明,C60分子的损伤主要是由注入离子的核能量转移所造成,与电子能量转移无关.H离子注入C60薄膜后,1469 cm-1处特征拉曼峰向短波方向非对称展宽,这可能是注入的H离子通过电子能量转移使C60分子发生聚合的结果.
关键词: 相似文献
237.
238.
Nanocrystalline porous TiO2 films were prepared on conducting glass supports (ITO) by processed commercial TiO2 nanometre powder (P25). Three methods of physical dispersing for TiO2 powder, i.e. grinding, magnetic stirring, sonicleaning, were used to disperse TiO2 nanometre powder. Surface morphologies of TiO2 films were observed by optic-microscope and SEM. It is found that the surface morphologies of TiO2 films are determined not only by the dispersing methods but also by the percentage of TiO2 powder in the dispersing system. Different film morphologies can be obtained under the same preparation condition but with different dispersing methods. A lot of cracks exist on the film surface for which the TiO2 slurry is dispersed by grinding. Magnetic stirring leads to some white points and micro-holes on the film surface. Only a few of micro-holes can be observed on the film surface, in which the TiO2 slurry is dispersed by sonicleaning. Different surface morphologies can also be found with different thicknesses of TiO2 films. Different film thicknesses are due to different percentages of TiO2 powder in the slurry. The related mechanism leading to different features of the surface morphologies for the TiO2 films is discussed. 相似文献
239.
We use a diamond anvil cell for the first time to investigate the Raman spectra of an aqueous micellar solution of hexadecyltrimethylammonium bromide (CTAB) at pressures up to 3.85 GPa. The pressure-induced phase transition between the micellar and coagel phases is found to occur at 0.64 GPa and 60℃. This phase transition has a pressure hysteresis, and thus exhibits the first-order phase transition properties. Further experimental results show that although the structure of the coagel phase is similar to that of the CTAB crystal, the interchain distance is slightly larger in the coagel phase than that in the CTAB crystal. 相似文献
240.
在原单脉冲直线感应加速器(LIA)组元的基础上,利用电缆延时和电缆反射两种方式获得了间隔500~1 000 ns的猝发双脉冲输出。在感应加速腔上进行了双脉冲实验,获得了幅度大于200 kV、前沿小于35 ns、平顶大于60 ns的双脉冲加速电压波形。两种方式中第一个脉冲的前沿和幅度都达到了原单脉冲组元的水平,表明加速腔负载的变化对波形没有明显影响,但由于电缆对波形的损耗,第二个脉冲的幅度和前沿比第一个脉冲略差。可以利用水介质传输线来代替长电缆,减小传输线的长度及其对波形的损耗。两个脉冲间的幅度差异可以通过改变长电缆的阻抗来调节。实验表明,通过这两种猝发双脉冲的产生方式并结合加速腔磁芯的改进,可简单高效地完成原单脉冲LIA的双脉冲改造。 相似文献