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981.
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
982.
研究了原位聚合法制备聚酰胺/聚苯胺导电纤维,并对制备的复合纤维进行红外及光学显微镜测试,结果表明聚苯胺与纤维成功复合。对制备的复合纤维进行电导率测试,采用控制单一变量法探讨了苯胺单体在不同的条件下聚合对纤维电导率的影响,并讨论了反应温度对聚合过程和电导率的影响,得出最佳的工艺条件为:纤维经30%的甲酸溶液预处理20min,苯胺单体浓度为0.8M,氧化剂过硫酸铵浓度为1M,掺杂酸为盐酸,浓度为0.8M,冰水浴条件,反应时间为4h,得到的聚酰胺/聚苯胺导电纤维的电导率为3.7S/m。 相似文献
983.
Based on molecular dynamics simulations, the plastic deformation of silver nanowires under uniaxial tension has been studied systematically. In this paper, the mechanical properties of [111]-oriented twin nanowires with different hole sizes have been studied. The existence of holes has no effect on the elastic deformation stage. The hole on the twin boundary has two main roles in the plastic deformation stage. During the initial stages of plastic deformation, the main function of the hole is to produce new dislocations as dislocation sources at small hole sizes.Upon increasing the hole size, the main effect changes to stop dislocation slip. During the late stages of plastic deformation, the two functions of the hole complement each other, upon increasing the hole size, the function of the hole as dislocation sources becomes obvious, leading to weakening of the plasticity of the nanowires. 相似文献
984.
基于经典命题逻辑的真度理论,讨论了经典命题逻辑系统当中公式集的约简问题。提出了真度约简及α-真度约简的概念,为公式集的约简提供了一种可行的操作方法。 相似文献
985.
以鸡蛋的卵清蛋白作为蛋白质药物模板、生物可降解材料聚己内酯(PCL)为药物载体模板,采用同轴电喷法制备PCL-蛋清体系的复合微球.研究了电导率、黏度对于电喷微球成型的影响.核壳溶液推进速率比、电压、溶液质量分数和接收距离等对于所得微球表面形态和结构的影响.利用扫描电子显微镜(SEM)研究了微球的表面形态,用荧光显微镜表征了微球的包覆模式.结果表明:同轴电喷法可以制备PCL-蛋清体系的复合结构微胶囊,其中推进速率比对微球形貌、粒径及其分布的影响比较明显,当PCL与蛋清溶液推进速率比大于10时,将出现具有包覆结构的微球. 相似文献
986.
Gallium Nitride (GaN) room temperature α particle detectors are fabricated and characterized, whose device structure is Schottky diode. The current-voltage (I- V) measurements reveal that the reverse breakdown voltage of the detectors is more than 200 V owing to the consummate fabrication processes, and that the Schottky barrier and ideal factor of the detectors are 0.64 eV and 1.02, respectively, calculated from the thermionic transmission model. ^241Am α particles pulse height spectra from the GaN detectors biased at -8 V is obviously one Gauss peak located at channel 44 with the full width at half maximum (FWHM) of 15.87 in channel. One of the main reasons for the relatively wider FWHM is that the air between the detectors and isotope could widen the spectrum. 相似文献
987.
详细地介绍了辉光放电质谱分析中的质谱干扰如同量异位素、多原子离子和多电荷离子干扰。从同位素选择、高分辨率仪器、碰撞诱导解离、离子源冷却、数学方法校正、放电气体更换和放电气体纯度提高等方面对辉光放电质谱的质谱干扰校正方法的现状进行了评述(引用文献共68篇)。 相似文献
988.
Broadband Convergence of 40 GHz-ROF and 10-Gb/s WDM-PON Systems in the Duplex Access Network 下载免费PDF全文
A broadly converged 40G-ROF and 10-Gb/s WDM-PON multi-service access system is proposed and exper- imentally demonstrated. This scheme consists of an integrated system of 40G-ROF and 10-Gb/s WDM-PON simultaneously transmitting independent 2.5-Gb/s wireless and 10-Gb/s wire signal. At the base station, it employs a remodulation scheme, which is achieved by remodulating the upstream OOK signal on the DPSK downstream signal, to reduce the cost of the base station. The transmission experiment is carried out over a 25-km-long single mode fiber (SMF-28). The results show that the sensitivities of downstream PON and ROF signal are -14.5 dBm and -21.5 dBm, respectively, and the sensitivity of upstream signal is -25.3 dBm. 相似文献
989.
YU Tao 《中国科学 数学(英文版)》2011,(9)
In this paper we first prove that a dual Hankel operator R φ on the orthogonal complement of the Dirichlet space is compact for φ∈ W 1,∞(D),and then that a semicommutator of two Toeplitz operators on the Dirichlet space or two dual Toeplitz operators on the orthogonal complement of the Dirichlet space in Sobolev space is compact.We also prove that a dual Hankel operator R φ with φ∈ W 1,∞(D) is of finite rank if and only if B φ is orthogonal to the Dirichlet space for some finite Blaschke product B,and give ... 相似文献
990.
Solid lipid nanoparticles loaded with bovine serum albumin(BSA) were prepared by a double emulsion method. As the mass fraction of the model drug BSA increased from 0 to 15%, the particle size gradually increased. The physical stability of the nanoparticles was investigated by zeta potential measurement and they were shown to be quite stable. Fluorescence spectroscopy confirmed that the loaded position of BSA was on the interface between the inner aqueous phase and the solid lipid phase. Both Fourier-transf... 相似文献