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991.
Z.-W.?He W.-X.?Sun X.-Q.?Liu D.-Y.?Xu J.?Gou Y.-Y.?WangEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,48(4):463-468
Nanoporous SiO2 thin films with ultra-low
dielectric constants were synthesized using a molecular template method.
Uniform films with pore size between 10 and 20 nm were obtained as observed
by N2 adsorption/desorption isotherms and transmission electron
microscopy. Fourier transform infrared spectroscopy (FTIR) and differential
thermal analysis were carried out to investigate the effect of n-hexane
washing on structural properties before and after the surface modification
process. The results showed that –OH bonds were substituted with –CH3 bonds in the films as a result of modification of trimethylchlorosilane
(TMCS)/n-hexane solution. Four kinds of model were used to analyze the
relationship between porosity and dielectric constant of the films, where
the dielectric constant was determined from capacitance-voltage
measurements. The investigation indicated that the corresponding
relationship was in accord with that estimated by the Rayleigh model. 相似文献
992.
研究了在硫酸铵存在下,碘化物-4-氨基安替吡啉体系萃取镉的行为以及丙醇水溶液的分相条件。实验表明,丙醇作为萃取溶剂能萃取中性离子缔合物。调节溶液pH=2.0—3.0,该体系能使Cd2 从常见过渡元素Fe~(2 )、Co~(2 )、Mn~(2 )、Ni~(2 )、Zn~(2 )的混合液中分离出来。 相似文献
993.
ZHOU Yun ZHU Shi-Qun WU Liang 《理论物理通讯》2005,44(12)
In a coupled laser system, the dynamics of the receiving laser is investigated when two separate transmitting lasers are injected into the receiving laser with different coupling strengths. It is shown that the phenomenon of preference of chaotic synchronization appears under appropriate coupling conditions. The receiving laser will entrain the pulses of either one or both transmitting lasers when the coupling is strong while it keeps its own dynamics when the coupling is weak. 相似文献
994.
In this work, the nitrogen molecular dissociation and ionization levels in Ar/N2 flue plasma are evaluated as functions of plasma parameters such as Ar mixture quantity and N2 flux in order to obtain the best condition for various applications such as thin film deposition and material surface modification. This plasma is operated at 10 kV and the nitrogen dissociation rate is determined by analyzing the optical emission of the nitrogen band. For different operating conditions, the dissociation rate [N] of N2 molecules was enhanced, as the mixture quantity of Ar increased from 0.06 m3/h to 0.9 m3/h and the max of enhancement factor is 4.3. This factor becomes bigger when the N2 flux becomes bigger. Moreover, the molecular nitrogen ionization density is calculated from the current intensity of the plasma. The ionization density was also enhanced, as the mixture quantity of Ar increased from 0.1 m3/h to 1.5 m3/h, under three different voltages. The max of enhancement factor of 1.96 is much smaller than the factor of the dissociation rate. These results are discussed in terms of the kinetics of the electrons, nitrogen ions, atoms and molecules. 相似文献
995.
Hameed Ullah Huafei Sun Abdul Majeed Siddiqui Tahira Haroon 《Journal of Applied Analysis & Computation》2019,9(1):140-158
This paper provides the analysis of the steady, creeping flow of a special class of slightly viscoelastic, incompressible fluid through a slit having porous walls with uniform porosity. The governing two dimensional flow equations along with non-homogeneous boundary conditions are non-dimensionalized. Recursive approach is used to solve the resulting equations. Expressions for stream function, velocity components, volumetric flow rate, pressure distribution, shear and normal stresses in general and on the walls of the slit, fractional absorption and leakage flux are derived. Points of maximum velocity components are also identified. A graphical study is carried out to show the effect of porosity and non-Newtonian parameter on above mentioned resulting expressions. It is observed that axial velocity of the fluid decreases with the increase in porosity and non-Newtonian parameter. The outcome of this theoretical study has significant importance both in industry and biosciences. 相似文献
996.
Zhenkun Lei Hai Yun Yanru Zhao Yongming Xing Xuemin Pan 《Optics and Lasers in Engineering》2009,47(6):701-707
An improved six-step phase-shifting method is proposed for calculating full-field shear stress based on a four-step color phase-shifting method in digital photoelasticity. The method was verified using a disk under diametral compression and then applied to an aluminum alloy/epoxy joint for studying the shear transfer behavior. Experimental results revealed that the isochromatic fringe order and shear stress at the bonding interface are distributed continuously and increased with compression. In particular, an antisymmetric thermal residual shear stress appears at the bonding interface, because of the difference in the thermal expansion coefficients of Al and the resin. This indicates that the thermal residual shear stress at the bonding interface is self-balanced and reaches a peak at the edges of the bonding interface. The load transfer is realized by the shear band from the bonding interface to the bottom support. Basically, the bonding interfacial shear stress is balanced with the load. 相似文献
997.
Multilayered BaTiO3(BTO)/Bi0.5K0.5TiO3 (BKT) thin films have been fabricated on Pt/Ti/SiO2/Si substrates using a metalloorganic decomposition process. XRD investigation of the resultant BTO/BKT multilayered thin films shows that they retain a perovskite-related structure type. They also exhibit a well-defined, polarization–electric field hysteresis loop with a measured remnant polarization (2Pr) of 5 µC/cm2 at an applied electric field of 250 kV/cm. The measured dielectric constant and dielectric loss at 10 kHz is 470 and 0.07 respectively. These multilayer BTO/BKT films maintain an excellent fatigue-free character even after 109 switching cycles. The mechanism associated with the enhancement of the electrical properties of the synthesized BTO/BKT films is also discussed. 相似文献
998.
Ling Zhou Bing-hua Sun Zhong-ying Jiang Jian-guo Zhang Hai-ying Gu 《Physica A》2009,388(15-16):3093-3099
We construct a functional for amphiphile–polymer mixtures and investigate the demixing transition by using a proposed version of density functional theory. It is found that increase of the amphiphilic size ratio and polymer length can effectively promote phase separation of the systems. Phase diagrams are plotted to clarify these influences. The results provide an effective way of controlling the stability of the fluid–fluid phase equilibrium of the mixtures. 相似文献
999.
提出一种能精确考虑固体结合能的通用状态方程,并且在高压和膨胀区域都具有正确的行为,不会出现物理上不正确的振荡现象.将新方程与文献中的典型方程应用于15种碱金属卤化物和一种碱土金属氧化物,结果表明新方程在给出正确结合能数据的同时,能够很好地拟合实验压缩数据.由Vinet方程和Morse方程定出的参数随数据范围变化很明显,新方程定出的参数随数据范围变化不明显.新方程的通用性优于Vinet方程和Morse方程.
关键词:
固体
通用状态方程
结合能
碱金属卤化物 相似文献
1000.
Direct transition of potential of water droplets to electric energy using aligned single-walled carbon nanotubes 下载免费PDF全文
In this paper, we report that an electromotive force (EMF)
can be induced in a rope of aligned single-walled carbon nanotubes
(SWNTs) when water droplets fall on this rope. The magnitude of this
EMF depends sensitively on the slant angle of the SWNTs. Most
interestingly, both the magnitude and the direction of the induced
EFM can be modulated by applying a current to the SWNTs. The
concepts of electrical slip and no-slip are proposed and can be
quantitatively described by ``electrical slip resistance'. This
kind of generator does not need any magnet, rotor, {etc} and shows
quite a different operating mechanism and design compared with a
conventional large scale hydroelectric power generator. 相似文献