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351.
Johnston MB Whittaker DM Dowd A Davies AG Linfield EH Li X Ritchie DA 《Optics letters》2002,27(21):1935-1937
A compact, high-power emitter of half-cycle terahertz (THz) radiation is demonstrated. The device consists of an epitaxial InAs emitter upon a GaAs prism and produces THz pulses that are 20 times more powerful than those from conventional planar InAs emitters. This improvement is a direct result of reorienting the transient THz dipole such that its axis is not perpendicular to the emitting surface. 相似文献
352.
A. Bodek R. Breedon R.N. Coleman W. Marsh S. Olsen J.L. Ritchie B.C. Barish R.L. Messner M.H. Shaevitz E.J. Siskind F.S. Merritt H.E. Fisk Y. Fukushima P.A. Rapidis G. Donaldson S.G. Wojcicki 《Physics letters. [Part B]》1982,113(1):82-86
The rates for same-sign and opposite-sign dimuon events with missing energy (indicative of final-state neutrinos) have been measured in 278 GeV π?-Fe and 350 GeV proton-Fe collisions. The main source of opposite-sign events is two semi-leptonic decays of hadronically produced charm states. The same-sign events are consistent with background from pion and kaon decays. We obtain a limit of 0.044 (90% CL) on the fraction of D0 semileptonic decays that result in the wrong-sign muon and conclude that less than 9% (90% CL) of same-sign dimuon events produced in neutrino interactions can be attributed to D0-0 mixing. The data imply δm < 6.5 × 10?4 eV and for the difference in mass and inverse lifetime of the CP eigenstates of the D0. Limits on diffractive bottom production cross sections in proton and pion collisions are also presented. 相似文献
353.
D. B. Ingham J. A. Ritchie C. M. Taylor 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1992,43(1):191-206
The motion of a two-dimensional bubble which is moving between two parallel plates under the influence of a constant pressure has been investigated using the Boundary Element Method. A free surface location algorithm has been developed so that the profile of the bubble may be predicted over a large range of values of the surface tension. The numerically predicted results are compared with existing experimental data and the results are encouraging. 相似文献
354.
It is shown that the classical image potential acting between a point classical charge and a metal surface may be regarded as originating in the shifted zero point energy of the surface plasmon field. The retardation correction to the image potential is studied using the electron gas model. 相似文献
355.
Frlez E Pocanić D Baranov VA Bertl W Bychkov M Khomutov NV Korenchenko AS Korenchenko SM Kozlowski T Kravchuk NP Kuchinsky NA Li W Minehart RC Mzhavia D Ritchie BG Ritt S Rozhdestvensky AM Sidorkin VV Smith LC Supek I Tsamalaidze Z VanDevender BA Velicheva EP Wang Y Wirtz HP Ziock KO 《Physical review letters》2004,93(18):181804
We have studied radiative pion decays pi(+)-->e(+)nugamma in three broad kinematic regions using the PIBETA detector and a stopped pion beam. Based on Dalitz distributions of 41 601 events we have evaluated absolute pi-->enugamma branching ratios in the three regions. Minimum chi(2) fits to the integral and differential (E(e(+)),E(gamma)) distributions result in the axial-to-vector weak form factor ratio of gamma identical with F(A)/F(V)=0.443(15), or F(A)=0.0115(4) with F(V)=0.0259. However, deviations from standard model predictions in the high-E(gamma)-low-E(e(+)) kinematic region indicate the need for further theoretical and experimental work. 相似文献
356.
A?Pires M?Nelson AL?Pozniak M?Fisher B?Gazzard F?Gotch N?ImamiEmail author 《Journal of immune based therapies and vaccines》2005,3(1):7
Background
With the advent of antiretroviral therapy (ART) cases of immune reconstitution inflammatory syndrome (IRIS) have increasingly been reported. IRIS usually occurs in individuals with a rapidly rising CD4 T-cell count or percentage upon initiation of ART, who develop a deregulated immune response to infection with or without reactivation of opportunistic organisms. Here, we evaluated rises in absolute CD4 T-cells, and specific CD4 T-cell responses in 4 HIV-1+ individuals presenting with mycobacterial associated IRIS who received in conjunction with ART, IL-2 plus GM-CSF immunotherapy. 相似文献357.
358.
Graham AC Thomas KJ Pepper M Cooper NR Simmons MY Ritchie DA 《Physical review letters》2003,91(13):136404
We report conductance measurements of ballistic one-dimensional (1D) wires defined in GaAs/AlGaAs heterostructures in an in-plane magnetic field, B. When the Zeeman energy is equal to the 1D subband energy spacing, the spin-split subband N upward arrow intersects (N+1) downward arrow, where N is the index of the spin-degenerate 1D subband. At the crossing of N=1 upward arrow and N=2 downward arrow subbands, there is a spontaneous splitting giving rise to an additional conductance structure evolving from the 1.5(2e(2)/h) plateau. With further increase in B, the structure develops into a plateau and lowers to 2e(2)/h. With increasing temperature and magnetic field the structure shows characteristics of the 0.7 structure. Our results suggest that at low densities a spontaneous spin splitting occurs whenever two 1D subbands of opposite spins cross. 相似文献
359.
Colin Thunhurst Charles Ritchie John Friend Pauline Booker 《The Journal of the Operational Research Society》1992,43(2):81-94
In this paper we describe the work of the Community Operational Research Unit with the Thurnscoe Tenants Housing Co-operative. We discuss the various stages through which this work has progressed, from the initial contacts with the Co-operative, through a period of acting as external consultants, to a continuing process of working as, essentially, internal consultants. A variety of the projects with which the Unit has been involved are outlined. These demonstrate the breadth and eclecticism of community operational research. No attempt is made to evaluate the involvement and contribution of the Community Operational Research Unit in a systematic way in this paper. This will be the subject of a subsequent paper. 相似文献
360.