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51.
The concept of the residence time of an atom in a kink position was introduced to predict the structure of electrochemically deposited surface coatings. The residence time is obtained from the reciprocal value of the rate constant for separation from the kink position. Residence times and deposition rates determine the density of kink positions [ksp] on the growing metal film. For equilibrium conditions (Nernst potential), the density of kink positions [ksp]0 depends on the exchange current density i0 and on the residence time by the equation:
, where NL is Loschmidts or Avogadros number, F is Faradays constant and z is the charge of the metal ions in the electrolyte. Calculated values of residence times are presented for pure metals as well as for silver–lead and nickel–aluminium alloys.Contribution to the 3rd Baltic Conference on Electrochemistry, Gdansk-Sobieszewo, Poland, 23–26 April 2003Dedicated to the memory of Harry B. Mark, Jr. (28 February 1934–3 March 2003) 相似文献
52.
通过数值求解非波恩-奥本海默近似下的一维含时薛定谔方程,研究了蝴蝶结型纳米结构基元中氢分子离子高次谐波的产生.研究表明,在蝴蝶结型纳米结构基元内部产生的非均匀场的空间位置对高次谐波的发射有较大影响.当非均匀场的空间位置从30 a.u.平移到-30 a.u.时,高次谐波的截止位置被延展且形成光滑的超连续的谐波谱,并应用时频分析方法、经典三步模型以及电离概率等解释了高次谐波发射的物理机理.研究了高次谐波谱对非均匀场空间位置的依赖性与载波包络值的关系,发现随着载波包络值的变化,非均匀场在不同空间位置处的高次谐波谱变化趋势相同. 相似文献
53.
We chose a series of isoindigo-based conjugated polymer(ⅡDDT,ⅡDDT-C3 and ⅡDDT-C4) with different length of side chains and bifurcation positions to investigate the relationship between the degree of alignment and the length of side chains and bifurcation positions.We found that the dichroic ratio was increased from 2.37 to 5.23 when the side chain was longer and the bifurcation position was away from the backbone.The π-π stacking distance was decreased from 3.67 A to 3.61 A when the bifurcation position was away from the backbone because of its smaller hindrance and the d-spacing of the(100)was increased from 20.06 A to 25.21 A when the side chain was longer.All the polymers were adopted an edge-on orientation with the backbone paralleled with the long axis of fibers.The weak interaction of side-chain in ⅡDDT-C4 was beneficial for the molecules being rearranged in parallel during the contact line receding and the strong n-n interaction could accelerate the interchain assembly of the parallel molecules through π-π interaction to form aligned fibers. 相似文献
54.
S.A. Tashkun V.I. Perevalov J.-L. Teffo M. Lecoutre T.R. Huet A. Campargue D. Bailly M.P. Esplin 《Journal of Molecular Spectroscopy》2000,200(2)
The effective operator approach is applied to the calculation of both line positions and line intensities of the 13C16O2 molecule. About 11 000 observed line positions of 13C16O2 selected from the literature have been used to derive 84 parameters of a reduced effective Hamiltonian globally describing all known vibrational–rotational energy levels in the ground electronic state. The standard deviation of the fit is 0.0015 cm−1. The eigenfunctions of this effective Hamiltonian have then been used in fittings of parameters of an effective dipole-moment operator to more than 600 observed line intensities of the cold and hot bands covering the ν2 and 3ν2 regions. The standard deviations of the fits are 3.2 and 12.0% for these regions, respectively. The quality of the fittings and the extrapolation properties of the fitted parameters are discussed. A comparison of calculated line parameters with those provided by the HITRAN database is given. Finally, the first observations of the 2ν1 + 5ν3 and ν1 + 2ν2 + 5ν3 absorption bands by means of photoacoustic spectroscopy (PAS) is presented. The deviations of predicted line positions from observed ones is found to be less than 0.1 cm−1, and most of them lie within the experimental accuracy (0.007 cm−1) once the observed line positions are included in the global fit. 相似文献
55.
Fourier transform spectra of ethylene (C2H4) have been recorded in the 1800–2350?cm?1 (4.3–5.6?µm) spectral region using a Bruker IFS125HR spectrometer at a resolution of 0.004?cm?1 leading to the observation of six vibrational bands, ν 7?+?ν 8, ν 4?+?ν 8, ν 6?+?ν 10, ν 6?+?ν 7, ν 4?+?ν 6 and ν 3?+?ν 10. The corresponding upper state ro-vibrational levels were fit using a Hamiltonian matrix accounting for numerous interactions. A satisfactory fit could be obtained using a polyad of nine interacting states {81101,?7181,?4181,?81121,?61101,?6171,?4161,?31101,?3171} of which three (81101, 81121 and 3171) are unobserved dark states. As a result a much more accurate and extended set of Hamiltonian constants were obtained than previously derived. The following band centers were determined: ν 0(ν 7?+?ν 8)?=?1888.9783(20)?cm?1, ν 0(ν 4?+?ν 8)?=?1958.2850(20)?cm?1, ν 0(ν 6?+?ν 10)?=?2047.7589(20)?cm?1, ν 0(ν 6?+?ν 7)?=?2178.011(60)?cm?1, ν 0(ν 4?+?ν 6)?=?2252.8026(24)?cm?1 and ν 0(ν 3?+?ν 10)?=?2171.2397(20)?cm?1. Finally, a synthetic spectrum that could be useful for ethylene detection in planetary atmospheres was generated. 相似文献
56.
M.A. Suriadi C.S. TanQ.D. Zhang T.H. YipK. Sundaravadivelu 《Journal of magnetism and magnetic materials》2006
The increasing application of the hard disk drive in consumer electronic devices has pushed the usage of the small form factor hard drives. At the same time, the data storage industry continues to enhance the capacity and performance of computer hard disk drive. The concerns of track mis-registration caused by various runout still remain with the form factor change. The objective of the current study is to numerically investigate the airflow characteristic inside a 1 in hard disk drive. 相似文献
57.
58.
The Fourier transform spectrum of CH3OH in the 10 μm region has been re-examined at higher pressure and path length than heretofore, as part of a program to provide comprehensive CH3OH spectral data for astrophysical and atmospheric applications. With the increase in spectral sensitivity, it has been possible to assign new torsionally excited ν12=1 and ν12=2 subbands plus further high-K, ν12=0 subbands of the ν8 CO-stretching band. Upper-state term values have been determined, and have been fitted to J(J+1) power-series expansions in order to obtain the excited ν8 substate origins. A variety of weaker subbands from other modes has also been identified in the 10 μm spectrum including ν12=0, ν12=1, and ν12=0←1 torsional subbands of the ν7 in-plane CH3 rock, ν12=0←1 and ν12=0←2 torsional combination subbands of the ν6 OH bend, and ν12=0←2 subbands of the ν5 symmetric CH3 bend. Line intensities have been retrieved line-by-line from the spectra. A large set of “unperturbed” ν8 transitions has been modeled using the same type of multi-parameter effective Hamiltonian employed successfully for the ground state, with inclusion of the intensities of a subset of the stronger ν8 spectral lines in the fitting in order to obtain appropriate transition dipole terms. Together, a 10 μm methanol database in HITRAN format has been generated. 相似文献
59.
The introduction of fluorophores into RNA for both in vitro and in cellulo studies of RNA function and cellular distribution is a subject of great current interest. Here I briefly review methods, some well-established and others newly developed, which have been successfully exploited to site-specifically fluorescently label interior positions of RNAs, as a guide to investigators seeking to apply this approach to their studies. Most of these methods can be applied directly to intact RNAs, including (1) the exploitation of natural posttranslational modifications, (2) the repurposing of enzymatic transferase reactions, and (3) the nucleic acid-assisted labeling of intact RNAs. In addition, several methods are described in which specifically labeled RNAs are prepared de novo. 相似文献
60.
H. Zessin 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2008,43(1):59-65
The aim of this note is to introduce for point processes in ? d the notions general position and reinforced general position, and to characterize these processes. As a consequence we show that Poisson processes P ρ with an infinite intensity measures ρ are in general position iff ρ is diffuse in the sense that any affine subspace of dimension d ? 1 is a ρ-nullset. Moreover, P ρ is in reinforced general position iff in addition any (d ? 1)-sphere is a ρ-nullset. 相似文献