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61.

Background  

Our group previously demonstrated that a DNA plasmid encoding the mycobacterial 65-kDa heat shock protein (DNA-HSP65) displayed prophylactic and therapeutic effect in a mice model for tuberculosis. This protection was attributed to induction of a strong cellular immunity against HSP65. As specific immunity to HSP60 family has been detected in arthritis, multiple sclerosis and diabetes, the vaccination procedure with DNA-HSP65 could induce a cross-reactive immune response that could trigger or worsen these autoimmune diseases.  相似文献   
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Inelastic scattering induces dephasing in mesoscopic systems. An analysis of previous models to simulate inelastic scattering in such systems is presented and a relatively new model based on wave attenuation is introduced. The problem of Aharonov-Bohm (AB) oscillations in conductance of a mesoscopic ring is studied. We show that the conductance is symmetric under flux reversal and the visibility of AB oscillations decays to zero as a function of the incoherence parameter, signaling dephasing. Further the wave attenuation model is applied to a fundamental problem in quantum mechanics, that of the conditional (reflection/transmission) times spent in a given region of space by a quantum particle before scattering off from that region.  相似文献   
64.
通过对激光驱动Cu等离子体实验的分析,认为对于自动线匹配光泵浦类Ne铜,在适当的条件下能够达到粒子数反转;而能否获得可观的增益,取决于两等离子体的耦合方式及驱动泵浦靶的激光功率密度是否接近最佳值。  相似文献   
65.
 用无色散X射线谱仪分别在靶前后测量了飞秒激光辐照铜箔产生的Kα X射线,获得了能量转换效率。入射激光脉冲宽度33 fs,能量在50 mJ~5 J,强度1017~1019 W/cm2。靶后发射的Kα X射线强度随入射激光能量的增加而增加,其单色性较靶前好。采用100 μm厚靶,其能量转换率为2.2×10-5。  相似文献   
66.
In this work, we found that acids (i.e., HCl and NaHSO3) rather than bases could catalyze the cyclization of o‐alkynylphenylphosphonic acid monoesters at slow rates and give phosphaisocoumarins in low to medium yields, whereas the cyclization of (o‐hydroxyphenyl)ethynylphosphinates proceeded very smoothly under basic conditions rather than acidic conditions, and a series of phosphachromones could be prepared in excellent yields at room temperature using K2CO3 as catalyst. This is the first example of the synthesis of phosphorus heterocycles via acid/base‐catalyzed intramolecular cyclization of alkynes. Possible mechanisms were discussed. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:649–652, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20728  相似文献   
67.
本文描述在LF-11激光装置上进行的线状锗等离子体电子温度时间分辨诊断的实验。在实验中利用时间分辨X射线晶体谱仪测量了线状锗等离子体X射线的时间分辨谱,并借助碰撞辐射模型(CR模型),由类Ne锗L线特征线相对强度比确定出锗等离子体的电子温度及其时间演化过程。并与用部分局部热平衡模型(PLTE)得出的结果做了比较。  相似文献   
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We systematically investigated the photoluminescence (PL) and transmittance characteristics of ZnO-SiO2 opals with varied positions of the stop-band and film thicknesses. An improved ultraviolet (UV) luminescence was observed from ZnO-SiO2 composites over pure ZnO nanocrystals under 325 nm He-Cd laser excitation at room temperature. The UV PL of ZnO nanocrystals in SiO2 opals with stop-bands center of 410 nm is sensitive to the thickness of opal films, and the UV PL intensity increases with the film thickness increasing. The PL spectra of ZnO nanocrystals in SiO2 opals with stop-bands center of 570 nm show a suppression of the weak visible band. The experimental results are discussed based on the scattering and/or absorbance in opal crystals.  相似文献   
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Much is known about the connection between the growth and decayof subharmonic functions. The results indicate that there isa general principle: asubharmonic function cannot decay ‘toofast’ relative to its growth.Three theorems are provedwhich, together with work previously published elsewhere, givea fairly complete account of how this principle works out fora subharmonic function having extremal decay along a ray. 1991Mathematics Subject Classification: 30D20, 31A05.  相似文献   
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