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This paper explores the potential of controlling quantum systems by
introducing ancillary systems and then performing unitary operation
on the resulting composite systems. It generalizes the concept of
pure state controllability for quantum systems and establishes the
link between the operator controllability of the composite system and
the generalized pure state controllability of its subsystem. It is
constructively demonstrated that if a composite quantum system can be
transferred between any pair of orthonormal pure vectors, then its
subsystem is generalized pure-state controllable. Furthermore, the
unitary operation and the coherent control can be concretely given to
transfer the system from an initial state to the target state.
Therefore, these properties may be potentially applied in quantum
information, such as manipulating multiple quantum bits and creating
entangled pure states. A concrete example has been given to
illustrate that a maximally entangled pure state of a quantum system
can be generated by introducing an ancillary system and performing
open-loop coherent control on the resulting composite system. 相似文献
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聚苯胺及聚邻甲基苯胺的直接裂解质谱研究 总被引:1,自引:0,他引:1
本文用直接裂解质谱和裂解色谱/质谱研究了不同氧化程度聚苯胺(PAn)和聚邻甲基苯胺(POT)的裂解过程及链结构,并用碰撞诱导解离(CID)和联合扫描(B/E)等技术探讨了链的断裂机理。结果表明,聚苯胺及其衍生物在650℃下裂解时产生5个单元的线状齐聚物,PAn及POT中苯二胺和醌亚胺两种结构单元共存。并提出了PAn和POT的自由基过渡态热解机理。 相似文献
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研究了成像板辐射图像测量的基本原理及其物理机制,并将其应用于伽马图像测量。建立了MS,SR和TR三种类型成像板数值模拟模型,分别使用MCNPX程序和基于Geant4开发的NPE程序计算了三种成像板对不同能量伽马射线的能量沉积,计算结果表明:SR和MS成像板比TR成像板能量沉积在低能部分大3~5倍,高能部分大7~9倍。实验测量了MS成像板灵敏度随铜膜厚度的变化关系,测量结果与理论计算结果有较好的一致性。理论与实验结果表明:成像板伽马图像测量的空间分辨力优于50 m。 相似文献
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报道了基于脉冲宽度为16ns、波长为266nm、总能量为30mJ、时间分辨为1.6ns的紫外激光四分幅阴影成像系统,用于研究Z-pinch产生等离子体与在丝阵负载中心放置塑料泡沫材料相互作用输运规律,研究动态黑腔形成过程的主要物理因素。使用高能高密度激光束透射等离子体,依据等离子体对激光束吸收衰减特性诊断激光束通过等离子体后的空间强度分布,通过理论计算获得等离子体空间密度分布,获得等离子体产生的早期稳定性、箍缩速度等规律。实验研究表明,在X射线峰值前约-25ns等离子体开始压缩塑料泡沫,在峰值前-5ns压缩到最小,之后泡沫开始膨胀。在X射线峰值时刻泡沫直径由3mm压缩到直径约为1mm,对泡沫的最大压缩比约为9倍。实验测量压缩速度约为3.3×10~6 cm/s,并给出了不同时刻的磁流体不稳定结构分布。 相似文献
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质谱新技术在高聚物分析中的应用 总被引:1,自引:0,他引:1
本文综述了高聚物质谱分析的基本类型和基本原理及其在高分子结构分析中的应用。 相似文献
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Experimental studies on the basic characteristics of IPs applied inγ-ray imaging are carried out by utilizing isotopic y-ray sources.The 1.25 MeV y-ray sensitivity of the BAS-MS and BAS-TR imaging plates and their enhanced sensitivity by covering appropriate Compton conversion foils are measured based on the studies of the image intensity linear calibration,time attenuation laws and the influence of scanning parameter settings.The energy-dependent y-ray sensitivity of the IPs is also obtained by the studies of the measured sensitivity and the Monte Carlo simulated energy deposition in the IPs'sensitive layer.Furthermore,a method of a sandwich detection structure as well as its primary experimental validations are presented in order to increase the gamma-to-neutron ratio in a y/n mixed radiation field. 相似文献
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为减小散射中子等较低能量的中子对快中子图像的贡献,提出了在成像板前依次紧贴金属卡阈片和富氢元素薄片的能量卡阈式快中子成像方法.该方法通过改变卡阈片材料、厚度等参数,可有效降低成像结构对某一能段中子的相对灵敏度.以14 MeV中子照相为例设计的能量卡阈式成像结构为TR成像板依次覆盖约150μm Pb膜和500μm聚乙烯膜,计算表明该结构对8 MeV以下快中子灵敏度小于其对14 MeV中子灵敏度的30%.利用K400加速器DT中子源开展了验证实验,结果表明能量卡阈式快中子成像结构能够有效消除样品散射中子引起的边界增强效应. 相似文献
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