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21.
We report a novel application of an ultrathin-polymer-film-based, resonance-enhanced x-ray waveguide as a real-time nanoprobe for elucidating dilute, yet disordered, gold nanoparticles embedded in the polymer matrix. This nanoprobe promises a sensitivity enhancement of several orders of magnitude, hence revealing in real time the lateral nanoparticle distribution with subnanometer spatial resolution. We observed that the motion of the nanoparticles is strongly anisotropic, with in-plane coalescence taking place more rapidly than out-of-plane diffusion, which can ultimately facilitate the formation of two-dimensional structures. 相似文献
22.
Stopping and time reversing a light pulse using dynamic loss tuning of coupled-resonator delay lines 总被引:1,自引:0,他引:1
We introduce a light-stopping process that uses dynamic loss tuning in coupled-resonator delay lines. We demonstrate via numerical simulations that increasing the loss of selected resonators traps light in a zero group velocity mode concentrated in the low-loss portions of the delay line. The large dynamic range achievable for loss modulation should increase the light-stopping bandwidth relative to previous approaches based on refractive index tuning. 相似文献
23.
The European Physical Journal E - The buckling and twisting of slender, elastic fibers is a deep and well-studied field. A slender elastic rod that is twisted with respect to a fixed end will... 相似文献
24.
The scattering theory for the Klein Gordon equation, with time-dependent potential and in a non-static space-time, is considered.
Using the Klein Gordon equation formulated in the Hubert spaceL
2(R
3) and the Einstein’s relativistic equation in the spaceL
2(R
3, dx) and establishing the equivalence of the vacuum states of their linearized forms in the Hubert spaceL
2(R
3) with the help of unique symmetric symplectic operator, the time evolution unitary operatorU(t) has been fixed for the Klein Gordon equation, incorporating either the positive or negative frequencies, in the infinite
dimensional Hubert spaceL
2(R
3). 相似文献
25.
In this paper we have designed a Split-radix type FFT unit without using multipliers. All the complex multiplications required for this type of FFT are implemented using Distributed Arithmetic (DA) technique. A method is incorporated to overcome the result overflow problem introduced by DA method. Proposed FFT architecture is implemented in 180 nm CMOS technology at a supply voltage of 1.8 V. 相似文献
26.
The non quantized nature of user rate wastes the code capacity in Orthogonal Variable Spreading Factor Codes (OVSF) based
Code Division Multiple Access (CDMA) systems. The code sharing scheme in multi code CDMA is proposed to minimize the code
rate wastage. The scheme combines the unused (wastage) capacity of already occupied codes to reduce the code blocking problem.
Simulation results are presented to show the superiority of the proposed code assignment scheme as compared to existing schemes.
相似文献
Sunil V. BhooshanEmail: |
27.
Hu X Jiao X Narayanan S Jiang Z K Sinha S Lurio LB Lal J 《The European physical journal. E, Soft matter》2005,17(3):353-359
We have used measurements of the absolute intensity of diffuse X-ray scattering to extract the interfacial tension of a buried polymer/polymer interface. Diffuse scattering was excited by an X-ray standing wave whose phase was adjusted to have a high intensity at the polymer/polymer interface and simultaneously a node at the polymer/air interface. This method permits the capillary-wave-induced roughness of the interface, and hence the interfacial tension, to be measured independently of the polymer/polymer interdiffusion. 相似文献
28.
Animesh K. Ojha Sunil K. Srivastava B. P. Asthana Ranjan K. Singh 《Journal of Raman spectroscopy : JRS》2007,38(2):159-165
The isotropic and anisotropic parts of the Raman spectra of NH2 bending and ν(CO) stretching modes of HCONH2 in a hydrogen‐bonding solvent, methanol, at different concentrations have been analyzed carefully in order to study the noncoincidence effect (NCE). In neat HCONH2, the experimentally measured values of noncoincidence Δνnc are ∼11 and ∼18 cm−1 for the NH2 bending and ν(CO) stretching modes, which reduce to 0.45 and 1.14 cm−1, respectively at the concentration of HCONH2 in mole fraction, χm = 0.1. The experimental results have been explained on the basis of two models, namely, the microscopic prediction of Logan and the macroscopic model of Mirone and Fini. The relative success of the two models in explaining the experimental data for both the modes have been discussed. It has been observed that in case of the ν(CO) stretching vibrational mode the Logan model can reproduce the experimental data rather precisely, whereas in the case of the NH2 bending mode, Mirone and Fini model yields more accurate results. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
29.
Present work explored a room temperature, simple and low cost chemical route for the preparation of hydrophilic cobalt oxide films from alkaline cobalt chloride (CoCl2:6H2O) and double distilled water precursor solutions. As-deposited cobalt oxide films showed amorphous nature, which is one of the prime requirements for supercapacitor, as confirmed from X-ray diffraction studies. Changes in direct band gap energy and electrical resistivity of as-deposited cobalt oxide films were confirmed after annealing. Spherical grains of about 40-50 nm diameters were uniformly distributed over the substrate surface. Surface wettability studied in contact with liquid interface, showed hydrophilic nature as water contact angle was <90°. Finally, presence of cobalt-oxygen covalent bond was observed from Raman shift experiment. 相似文献
30.
New substituted thieno[3,2-c]pyridine derivatives 5 were synthesized by the reaction of 3-bromo-4-chlorothieno[3,2-c]pyridine 1 with cyclic amine 2, which further on Suzuki reaction with boronic acids 4 converted to corresponding 3-arylthieno[3,2-c]pyridine 5. Substituent R3 has predominant effect on fluorescence properties of thienopyridines. However, the electron donor amine at C4 has no effect on fluorescence properties of thienopyridines. 相似文献