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By using quantum bang-bang control technique, we studied the suppression of amplitude damping, or energy dissipation, in a
three-level atom in various configurations. We have explicitly given the bang-bang control groups in three different configurations,
and the pulse sequences for these bang-bang control operations.
Supported by the National Natural Science Foundation of China (Grant No. 10547003), the Key Project of Chinese Ministry of
Education (Grant No. 306020) and Chifeng College Scientific Research Fund (Grant No. ZRZD200604) 相似文献
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Effects of various solar indices on accuracy of Earth’s thermospheric neutral density models 总被引:1,自引:0,他引:1
Four kinds of solar indices F10.7, E10.7, S10, Mg10 and four thermospheric neutral density models, i.e., CIRA72, DTM94, NRLMSISE00 and JB2006, are discussed. The CHAMP accelerometer data are used to calculate thermospheric total mass density. Based on the comparison of the model densities with CHAMP observations, the effects of various indices on the model accuracy are detected. It is found that under quiet and moderate solar conditions (F10.7<160), all of the models’ errors are reduced about 15% by using E... 相似文献
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Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall. 相似文献
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LI HongBo LI Jing YANG ZhanJun XU Qin & HU XiaoYa College of Chemistry Engineering Yangzhou University Yangzhou China Chemistry Biology Engineering School Yancheng Institute of Technology Yancheng China 《中国科学B辑(英文版)》2011,(1)
A sub-picomole level topotecan hydrochloride determination method was first proposed using sodium dodecyl sulfate (SDS) as a sensitized reagent at a novel disposable electrode (an improved wax-impregnated graphite electrode).The effects of different kinds of surfactants on the electrochemical response to topotecan hydrochloride were examined.The results indicate the electrochemical signal was apparently improved by SDS.At optimal conditions,the oxidative peak current increased linearly with the logarithm of... 相似文献
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提出了在一次性电极(改进的石墨浸蜡电极)上,利用十二烷基磺酸钠增敏电化学法亚皮摩尔级测定拓扑替康盐酸盐的方法.考察了不同种类的表面活性剂对拓扑替康盐酸盐的电化学响应.结果表明,十二烷基磺酸钠能够显著地提高其电化学响应.在优化的实验条件下,氧化峰电流跟拓扑替康盐酸盐浓度的对数在2.0×10-12至1.0×10-11mol/L和8.0×10-11至8.0×10-10mol/L范围内成线性关系,检出限为6.4×10-13mol/L.该方法用于检测尿液中的拓扑替康盐酸盐. 相似文献
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In this paper, we discuss tail asymptoticsproperties for a class of infinite phase type distributions based onprobability generating function or Laplace-Stieltjes transform. The results show that, unlike finite phase cases, the tail asymptotics for the infinite phase type distributions we considered do not decay
geometrically or exponentially. 相似文献
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Coordination polymeric solid, {[Ag 2 (bpp) 2 (H 2 O) 2 ](chd)·9H 2 O} n (1) (bpp = 1,3-bis(4-pyridyl) propane, H 2 chd = 1,4-cyclo-hexanedicarboxylic acid), has been obtained by the solution phase ultrasonic synthesis techniques. The structure established through X-ray structural analysis shows that the compound traps an interesting 1D water tape built by the alternating "three-pointed star" cage-like pentameric and D 2h tetrameric clusters (C2/c, Z = 4; a = 30.37(2) , b = 9.271(5) , and c = 18.89(1) ; β = 128.47°; V = 4164(4) 3 ). The novelty of the present complex is the rarely crystallographic example of the cage-shaped water pentamer, which is usually ascribed to a less-stable species. A first-principle density functional theory (DFT) calculation demonstrates that the interconnectivity between cage-like pentamers and D 2h tetramers is beneficial for contribution to the structural stabilization of these less-stable water cluster species. 相似文献