22,165 research outputs found

    New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

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    A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    Cancellation of Infrared Divergences in Hadronic Annihilation Decays of Heavy Quarkonia

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    In the framework of a newly developed factorization formalism which is based on NRQCD, explicit cancellations are shown for the infrared divergences that appeared in the previously calculated hadronic annihilation decay rates of P-wave and D-wave heavy quarkonia. We extend them to a more general case that to leading order in v2v^2 and next-to-leading order in αs\alpha_s, the infrared divergences in the annihilation amplitudes of color-singlet QQˉ(2S+1LJ)Q\bar{Q}(^{2S+1}L_J) pair can be removed by including the contributions of color-octet operators QQˉ(2S+1(L1)J)Q\bar{Q}(^{2S+1}(L-1)_{J'}), QQˉ(2S+1(L3)J)Q\bar{Q}(^{2S+1}(L-3)_{J''}), ... in NRQCD. We also give the decay widths of 3DJLH^3D_J\rightarrow LH at leading order in αs\alpha_s.Comment: 8 pages, LaTex(3 figures included), to be publishe

    Mitochondrial Control and Guidance of Cellular Activities of T Cells.

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    Immune cells protect us against infection and cancer cells, as well as functioning during healing processes to support tissue repairing and regeneration. These behaviors require that upon stimulation from immune activation the appropriate subsets of immune cells are generated. In addition to activation-induced signaling cascades, metabolic reprogramming (profound changes in metabolic pathways) also provides a novel form of regulation to control the formation of desirable immune responses. Immune cells encounter various nutrient compositions by circulating in bloodstream and infiltrating into peripheral tissues; therefore, proper engagement of metabolic pathways is critical to fulfill the metabolic demands of immune cells. Metabolic pathways are tightly regulated mainly via mitochondrial dynamics and the activities of the tricarboxylic acid cycle and the electron transport chain. In this review, we will discuss how metabolic reprogramming influences activation, effector functions, and lineage polarization in T cells, with a particular focus on mitochondria-regulated metabolic checkpoints. Additionally, we will further explore how in various diseases deregulation and manipulation of mitochondrial regulation can occur and be exploited. Furthermore, we will discuss how this knowledge can facilitate the design of immunotherapies

    Polarimetric Multispectral Imaging Technology

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    The Jet Propulsion Laboratory is developing a remote sensing technology on which a new generation of compact, lightweight, high-resolution, low-power, reliable, versatile, programmable scientific polarimetric multispectral imaging instruments can be built to meet the challenge of future planetary exploration missions. The instrument is based on the fast programmable acousto-optic tunable filter (AOTF) of tellurium dioxide (TeO2) that operates in the wavelength range of 0.4-5 microns. Basically, the AOTF multispectral imaging instrument measures incoming light intensity as a function of spatial coordinates, wavelength, and polarization. Its operation can be in either sequential, random access, or multiwavelength mode as required. This provides observation flexibility, allowing real-time alternation among desired observations, collecting needed data only, minimizing data transmission, and permitting implementation of new experiments. These will result in optimization of the mission performance with minimal resources. Recently we completed a polarimetric multispectral imaging prototype instrument and performed outdoor field experiments for evaluating application potentials of the technology. We also investigated potential improvements on AOTF performance to strengthen technology readiness for applications. This paper will give a status report on the technology and a prospect toward future planetary exploration

    The meson BcB_c annihilation to leptons and inclusive light hadrons

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    The annihilation of the BcB_c meson to leptons and inclusive light hadrons is analyzed in the framework of nonrelativistic QCD (NRQCD) factorization. We find that the decay mode, which escapes from the helicity suppression, contributes a sizable fraction width. According to the analysis, the branching ratio due to the contribution from the color-singlet component of the meson BcB_c can be of order (10^{-2}). We also estimate the contributions from the color-octet components. With the velocity scaling rule of NRQCD, we find that the color-octet contributions are sizable too, especially, in certain phase space of the annihilation they are greater than (or comparative to) the color-singlet component. A few observables relevant to the spectrum of charged lepton are suggested, that may be used as measurements on the color-octet and color-singlet components in the future BcB_c experiments. A typical long distance contribution in the annihilation is estimated too.Comment: 26 pages, 5 figures (6 eps-files), submitted to Phys. Rev.

    Well-posedness of the Viscous Boussinesq System in Besov Spaces of Negative Order Near Index s=1s=-1

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    This paper is concerned with well-posedness of the Boussinesq system. We prove that the nn (n2n\ge2) dimensional Boussinesq system is well-psoed for small initial data (u0,θ0)(\vec{u}_0,\theta_0) (u0=0\nabla\cdot\vec{u}_0=0) either in (B,11B,1,1)×Bp,r1({B}^{-1}_{\infty,1}\cap{B^{-1,1}_{\infty,\infty}})\times{B}^{-1}_{p,r} or in B,1,1×Bp,1,ϵ{B^{-1,1}_{\infty,\infty}}\times{B}^{-1,\epsilon}_{p,\infty} if r[1,]r\in[1,\infty], ϵ>0\epsilon>0 and p(n2,)p\in(\frac{n}{2},\infty), where Bp,qs,ϵB^{s,\epsilon}_{p,q} (sRs\in\mathbb{R}, 1p,q1\leq p,q\leq\infty, ϵ>0\epsilon>0) is the logarithmically modified Besov space to the standard Besov space Bp,qsB^{s}_{p,q}. We also prove that this system is well-posed for small initial data in (B,11B,1,1)×(Bn2,11Bn2,1,1)({B}^{-1}_{\infty,1}\cap{B^{-1,1}_{\infty,\infty}})\times({B}^{-1}_{\frac{n}{2},1}\cap{B^{-1,1}_{\frac{n}{2},\infty}}).Comment: 18 page

    Pseuduscalar Heavy Quarkonium Decays With Both Relativistic and QCD Radiative Corrections

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    We estimate the decay rates of ηc2γ\eta_c\rightarrow 2\gamma, ηc2γ\eta_c'\rightarrow 2\gamma, and J/ψe+eJ/\psi\rightarrow e^+ e^-, ψe+e\psi^\prime\rightarrow e^+e^-, by taking into account both relativistic and QCD radiative corrections. The decay amplitudes are derived in the Bethe-Salpeter formalism. The Bethe-Salpeter equation with a QCD-inspired interquark potential are used to calculate the wave functions and decay widths for these ccˉc\bar{c} states. We find that the relativistic correction to the ratio RΓ(ηc2γ)/Γ(J/ψe+e)R\equiv \Gamma (\eta_c \rightarrow 2\gamma)/ \Gamma (J/ \psi \rightarrow e^+ e^-) is negative and tends to compensate the positive contribution from the QCD radiative correction. Our estimate gives Γ(ηc2γ)=(67) keV\Gamma(\eta_c \rightarrow 2\gamma)=(6-7) ~keV and Γ(ηc2γ)=2 keV\Gamma(\eta_c^\prime \rightarrow 2\gamma)=2 ~keV, which are smaller than their nonrelativistic values. The hadronic widths Γ(ηc2g)=(1723) MeV\Gamma(\eta_c \rightarrow 2g)=(17-23) ~MeV and Γ(ηc2g)=(57) MeV\Gamma(\eta_c^\prime \rightarrow 2g)=(5-7)~MeV are then indicated accordingly to the first order QCD radiative correction, if αs(mc)=0.260.29\alpha_s(m_c)=0.26-0.29. The decay widths for bbˉb\bar b states are also estimated. We show that when making the assmption that the quarks are on their mass shells our expressions for the decay widths will become identical with that in the NRQCD theory to the next to leading order of v2v^2 and αs\alpha_s.Comment: 14 pages LaTex (2 figures included

    Soliton with a Pion Field in the Global Color Symmetry Model

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    We calculate the property of the global color symmetry model soliton with the pion field being included explicitly. The calculated results indicate that the pion field provides a strong attraction so that the eigen-energy of a quark and the mass of a soliton reduce drastically, in contrast to those with only the sigma field.Comment: 15 pages, 2 figure

    Decays of J/ψJ/\psi and ψ\psi^\prime into vector and pseudoscalar meson and the pseudoscalar glueball-qqˉq\bar{q} mixing

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    We introduce a parametrization scheme for J/ψ(ψ)VPJ/\psi(\psi^\prime)\to VP where the effects of SU(3) flavor symmetry breaking and doubly OZI-rule violation (DOZI) can be parametrized by certain parameters with explicit physical interpretations. This scheme can be used to clarify the glueball-qqˉq\bar{q} mixing within the pseudoscalar mesons. We also include the contributions from the electromagnetic (EM) decays of J/ψJ/\psi and ψ\psi^\prime via J/ψ(ψ)γVPJ/\psi(\psi^\prime)\to \gamma^*\to VP. Via study of the isospin violated channels, such as J/ψ(ψ)ρηJ/\psi(\psi^\prime)\to \rho\eta, ρη\rho\eta^\prime, ωπ0\omega\pi^0 and ϕπ0\phi\pi^0, reasonable constraints on the EM decay contributions are obtained. With the up-to-date experimental data for J/ψ(ψ)VPJ/\psi(\psi^\prime)\to VP, J/ψ(ψ)γPJ/\psi(\psi^\prime)\to \gamma P and PγγP\to \gamma\gamma, etc, we arrive at a consistent description of the mentioned processes with a minimal set of parameters. As a consequence, we find that there exists an overall suppression of the ψ3g\psi^\prime\to 3g form factors, which sheds some light on the long-standing "ρπ\rho\pi puzzle". By determining the glueball components inside the pseudoscalar η\eta and η\eta^\prime in three different glueball-qqˉq\bar{q} mixing schemes, we deduce that the lowest pseudoscalar glueball, if exists, has rather small qqˉq\bar{q} component, and it makes the η(1405)\eta(1405) a preferable candidate for 0+0^{-+} glueball.Comment: Revised version to appear on J. Phys. G; An error in the code was corrected. There's slight change to the numerical results, while the conclusion is intac
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