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31.
Sapienza R García PD Bertolotti J Martín MD Blanco A Viña L López C Wiersma DS 《Physical review letters》2007,99(23):233902
In this Letter we demonstrate Mie resonances mediated transport of light in randomly arranged, monodisperse dielectric spheres packed at high filling fractions. By means of both static and dynamic optical experiments we show resonant behavior in the key transport parameters and, in particular, we find that the energy transport velocity, which is lower than the group velocity, also displays a resonant behavior. 相似文献
32.
Kleemans NA Bominaar-Silkens IM Fomin VM Gladilin VN Granados D Taboada AG García JM Offermans P Zeitler U Christianen PC Maan JC Devreese JT Koenraad PM 《Physical review letters》2007,99(14):146808
We report the direct measurement of the persistent current carried by a single electron by means of magnetization experiments on self-assembled InAs/GaAs quantum rings. We measured the first Aharonov-Bohm oscillation at a field of 14 T, in perfect agreement with our model based on the structural properties determined by cross-sectional scanning tunneling microscopy measurements. The observed oscillation magnitude of the magnetic moment per electron is remarkably large for the topology of our nanostructures, which are singly connected and exhibit a pronounced shape asymmetry. 相似文献
33.
Lie symmetries and solitons in nonlinear systems with spatially inhomogeneous nonlinearities 总被引:1,自引:0,他引:1
Belmonte-Beitia J Pérez-García VM Vekslerchik V Torres PJ 《Physical review letters》2007,98(6):064102
Using Lie group theory and canonical transformations, we construct explicit solutions of nonlinear Schr?dinger equations with spatially inhomogeneous nonlinearities. We present the general theory, use it to show that localized nonlinearities can support bound states with an arbitrary number solitons, and discuss other applications of interest to the field of nonlinear matter waves. 相似文献
34.
This paper deals with the photo-induced fluorimetric determination of the herbicide Fluometuron with the aid of a continuous-flow
assembly of the emergent and new methodology known as Multicommutation which was provided with an on-line photoreactor. Maximum
fluorescence intensity was observed at basic pH solutions, 1×10−4 mol l−1 NaOH, after 1.4 min of irradiation and being the maximum at λexc 247.0 nm and λem 325.0 nm.
The influence of different experimental parameters either chemical (pH, surfactants presence, solvent polarity and temperature)
or hydrodynamic (time of photo-degradation, size and number of different segments and flow-rate) was tested.
The linear dynamic range was from 0.01 to 4.0 mg l−1 of Fluometuron; the inter-day reproducibility (as R.S.D.) of the slope was 0.001% and 1.7% from the peaks intra-day reproducibility.
A large series of potential interferents was studied and finally the method was applied to human urine, soil, formulation
and water samples. 相似文献
35.
Cdk1 is sufficient to drive the mammalian cell cycle 总被引:1,自引:0,他引:1
Santamaría D Barrière C Cerqueira A Hunt S Tardy C Newton K Cáceres JF Dubus P Malumbres M Barbacid M 《Nature》2007,448(7155):811-815
36.
Spin-orbit (SO) coupling--the interaction between a quantum particle's spin and its momentum--is ubiquitous in physical systems. In condensed matter systems, SO coupling is crucial for the spin-Hall effect and topological insulators; it contributes to the electronic properties of materials such as GaAs, and is important for spintronic devices. Quantum many-body systems of ultracold atoms can be precisely controlled experimentally, and would therefore seem to provide an ideal platform on which to study SO coupling. Although an atom's intrinsic SO coupling affects its electronic structure, it does not lead to coupling between the spin and the centre-of-mass motion of the atom. Here, we engineer SO coupling (with equal Rashba and Dresselhaus strengths) in a neutral atomic Bose-Einstein condensate by dressing two atomic spin states with a pair of lasers. Such coupling has not been realized previously for ultracold atomic gases, or indeed any bosonic system. Furthermore, in the presence of the laser coupling, the interactions between the two dressed atomic spin states are modified, driving a quantum phase transition from a spatially spin-mixed state (lasers off) to a phase-separated state (above a critical laser intensity). We develop a many-body theory that provides quantitative agreement with the observed location of the transition. The engineered SO coupling--equally applicable for bosons and fermions--sets the stage for the realization of topological insulators in fermionic neutral atom systems. 相似文献
37.
Peça J Feliciano C Ting JT Wang W Wells MF Venkatraman TN Lascola CD Fu Z Feng G 《Nature》2011,472(7344):437-442
Autism spectrum disorders (ASDs) comprise a range of disorders that share a core of neurobehavioural deficits characterized by widespread abnormalities in social interactions, deficits in communication as well as restricted interests and repetitive behaviours. The neurological basis and circuitry mechanisms underlying these abnormal behaviours are poorly understood. SHANK3 is a postsynaptic protein, whose disruption at the genetic level is thought to be responsible for the development of 22q13 deletion syndrome (Phelan-McDermid syndrome) and other non-syndromic ASDs. Here we show that mice with Shank3 gene deletions exhibit self-injurious repetitive grooming and deficits in social interaction. Cellular, electrophysiological and biochemical analyses uncovered defects at striatal synapses and cortico-striatal circuits in Shank3 mutant mice. Our findings demonstrate a critical role for SHANK3 in the normal development of neuronal connectivity and establish causality between a disruption in the Shank3 gene and the genesis of autistic-like behaviours in mice. 相似文献
38.
Antoine Salden Maik Budde Carolina Alejandra Garcia-Soto Omar Biondo Jairo Barauna Marzia Faedda Beatrice Musig Chloé Fromentin Minh Nguyen-Quang Harry Philpott Golshid Hasrack Domenico Aceto Yuxiang Cai Federico Azzolina Jury Annemie Bogaerts Patrick Da Costa Richard Engeln María Elena Gálvez Timo Gans Tomas Garcia Vasco Guerra Carlos Henriques Monika Motak Maria Victoria Navarro Vasile I.Parvulescu Gerard Van Rooij Bogdan Samojeden Ana Sobota Paolo Tosi Xin Tu Olivier Guaitella 《Journal of Energy Chemistry》2023,(11):318-342
This paper brings the comparison of performances of CO2 conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field, organised in an open access online database. This tool is open to all users to carry out their own analyses, but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made, and ultimately to improve the efficiency of CO2 conversion by plasma-catalys... 相似文献
39.
Ensemble averages of the sensitivity to initial conditions xi(t) and the entropy production per unit of time of a new family of one-dimensional dissipative maps, x(t+1)=1-ae(-1/|x(t)|(z))(z>0), and of the known logisticlike maps, x(t+1)=1-a|x(t)|(z)(z>1), are numerically studied, both for strong (Lyapunov exponent lambda(1)>0) and weak (chaos threshold, i.e., lambda(1)=0) chaotic cases. In all cases we verify the following: (i) both [ln((q)x triple bond (x(1-q)-1)/(1-q); ln((1)x=ln(x] and [S(q) triple bond (1- sigma p(q)(i))/(q-1); S(1)=- sigma p(i)ln(p(i)] linearly increase with time for (and only for) a special value of q, q(av)(sen), and (ii) the slope of and that of coincide, thus interestingly extending the well known Pesin theorem. For strong chaos, q(av)(sen)=1, whereas at the edge of chaos q(av)(sen)(z)<1. 相似文献
40.
We present an approximate analytical theory and direct numerical computation of defect modes of a Bose-Einstein condensate loaded in an optical lattice and subject to an additional localized (defect) potential. Some of the modes are found to be remarkably stable and can be driven along the lattice by means of a defect moving following a steplike function defined by the period of Josephson oscillations and the macroscopic stability of the atoms. 相似文献