排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
The stability and electronic properties of highly packed 1-hexyl-naphthalene (HNap) molecular wire on Si(0 0 1) have been studied with first principles DFT method. HNap assembles into a 1D arrangement on the Si(0 0 1)[2 × 1] surface on which molcules adopt a commensurate structure along a dimer row with an intermolecular distance of 3.8 Å. HNap is attached to the surface through the hexyl chain, and stands normal to the surface. This highly packed structure leads to the formation of delocalized π-orbitals over the entire wire but essentially localized on the naphthalene counterpart, and well separated from the Si surface states. Cohesion energy within the wire arises from a significant attraction between hexyl chains, and to a weaker stabilizing π–π interaction between naphthalenes. 相似文献
2.
Ricardo P. Beausoleil Gulnara Baldoquin Rodolfo A. Montejo 《Annals of Operations Research》2008,157(1):105-133
This paper deals with a multiobjective combinatorial optimization problem called Extended Knapsack Problem. By applying multi-start
search and path relinking we rapidly guide the search toward the most balanced zone of the Pareto-optimal front. The Pareto
relation is applied in order to designate a subset of the best generated solutions to be the current efficient set of solutions.
The max-min criterion with the Hamming distance is used as a measure of dissimilarity in order to find diverse solutions to
be combined. The performance of our approach is compared with several state-of-the-art MOEAs for a suite test problems taken
from the literature. 相似文献
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4.
Abbott B Abbott R Adhikari R Ageev A Allen B Amin R Anderson SB Anderson WG Araya M Armandula H Ashley M Asiri F Aufmuth P Aulbert C Babak S Balasubramanian R Ballmer S Barish BC Barker C Barker D Barnes M Barr B Barton MA Bayer K Beausoleil R Belczynski K Bennett R Berukoff SJ Betzwieser J Bhawal B Bilenko IA Billingsley G Black E Blackburn K Blackburn L Bland B Bochner B Bogue L Bork R Bose S Brady PR Braginsky VB Brau JE Brown DA Bullington A Bunkowski A Buonanno A Burgess R Busby D 《Physical review letters》2005,94(18):181103
We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars. 相似文献
5.
We propose a method for quantum information processing using molecules coupled to an external laser field. This utilizes molecular interactions, control of the external field, and an effective energy shift of the doubly excited state of two coupled molecules. Such a level shift has been seen in the two-photon resonance experiments recently reported by Hettich et al. Here we show that this can be explained in terms of the QED Lamb shift. We quantify the performance of the proposed quantum logic gates in the presence of dissipative mechanisms. The unitary transformations required for performing one- and two-qubit operations can be implemented with present day molecular technology. The proposed techniques can also be applied to coupled quantum dot and biomolecular systems. 相似文献
6.
Raymond G. Beausoleil 《Foundations of Physics》2014,44(8):856-872
In this paper, we will review research done by the Large-Scale Integrated Photonics group at HP Laboratories, and in particular we will discuss applications of optical resonances in dielectric microstructures and nanostructures to future classical and quantum information technologies. Our goal is to scale photonic technologies over the next decade in much the same way as electronics over the past five, thereby establishing a Moore’s Law for optics. 相似文献
7.
Kyle W. Knouse Laura E. Ator Lauren E. Beausoleil Zachary J. Hauseman Rebecca L. Casaubon Gregory R. Ott 《Tetrahedron letters》2017,58(3):202-205
Improved and expanded one-pot, two-component syntheses of bicyclic heterocycles containing a 3-N-acyl-3-amino-1,2-pyrazole motif from N′-hydroxy-carboxyamidines and acylbenzotriazoles have been developed. Importantly, this sequence obviates the need for hydrazine or N-aminating reagents to synthesize the key nitrogen–nitrogen (N–N) bond of these heterocycles, which is formed via Boulton-Katritzky rearrangement. A diverse array of pharmaceutically relevant N–N containing heterocycles has been prepared with this methodology using readily available reagents without the need for special equipment or conditions. 相似文献
8.
The zero-phonon transition rate of a nitrogen-vacancy center is enhanced by a factor of ~70 by coupling to a photonic crystal resonator fabricated in monocrystalline diamond using standard semiconductor fabrication techniques. Photon correlation measurements on the spectrally filtered zero-phonon line show antibunching, a signature that the collected photoluminescence is emitted primarily by a single nitrogen-vacancy center. The linewidth of the coupled nitrogen-vacancy center and the spectral diffusion are characterized using high-resolution photoluminescence and photoluminescence excitation spectroscopy. 相似文献
9.
Lin Zhang Yunchu Li Muping Song Jeng-Yuan Yang Raymond G. Beausoleil Alan E. Willner 《Applied Physics A: Materials Science & Processing》2009,95(4):1089-1100
Electro-optic modulation plays a critical role in implementing space-, power- and spectrally efficient optical interconnection
for high-capacity computing systems. Microring resonators exhibit a great potential to achieve compact, low power-consumption
and high-speed modulators. In this paper, we briefly review our efforts on designing and analyzing the microring modulators.
Three types of single-ring modulators are discussed, from device behavior to possible system impact. We then present two novel
double-ring modulators in which a passive ring resonator is added, enabling higher operation speed and lower power consumption.
We also describe an opportunity of introducing phase modulation data formats into the on-chip communication environment. In
this paper, our emphasis is placed on linking the devices’ physics to their system performance and providing potential technical
solutions to physical-layer challenges of optical interconnection. 相似文献
10.
Spillane SM Pati GS Salit K Hall M Kumar P Beausoleil RG Shahriar MS 《Physical review letters》2008,100(23):233602
We report the observation of low-light level optical interactions in a tapered optical nanofiber (TNF) embedded in a hot rubidium vapor. The small optical mode area plays a significant role in the optical properties of the hot vapor Rb-TNF system, allowing nonlinear optical interactions with nW level powers even in the presence of transit-time dephasing rates much larger than the intrinsic linewidth. We demonstrate nonlinear absorption and V-type electromagnetically induced transparency with cw powers below 10 nW, comparable to the best results in any Rb-optical waveguide system. The good performance and flexibility of the Rb-TNF system makes it a very promising candidate for ultralow power resonant nonlinear optical applications. 相似文献