Testing local-realism and macro-realism under generalized dichotomic measurements

Generalized quantum measurements with two outcomes are fully characterized by two real parameters, dubbed as sharpness parameter and biasedness parameter and they can be linked with different aspects of the experimental setup. It is known that sharpness parameter characterizes precision of the measurements and decreasing sharpness parameter of the measurements reduces the possibility of probing quantum features like quantum mechanical (QM) violation of local-realism (LR) or macro-realism (MR). Here we investigate the effect of biasedness together with that of sharpness of measurements and find a trade-off between those two parameters in the context of probing QM violations of LR and MR. Interestingly, we also find that the above mentioned trade-off is more robust in the latter case.     

A semi-automatic method for measuring interferometry fringes: prototype design and first results

A device for automatically obtaining the information contained in holographic interferometry fringes is proposed. The method may be applied to any kind of interferometric fringes. Accuracy has been demonstrated by contrasting the results obtained with our prototype system and those with the single-beam speckle interferometry technique for the measurement of displacements in a plane. The results show good correlation between the two series of measurements.     

Phase Distribution Measurement of Light Wave by Adaptive Control of Pupil Function with Local Algorithm

In developing a new method to measure the phase distribution of a light wave utilizing the adaptive control of the pupil function with a liquid crystal panel, the optimization procedure for the adaptive control is shown to improve when a local algorithm is adopted. The feasibility of the proposed system is confirmed by computer simulation as well as by some basic experiments.     

使用CCD测量玻璃管内液体界面位置的灵巧测量头

本文介绍一种使用线阵ＣＣＤ进行玻璃管内液位测量的光电测量头。与其他ＣＣＤ尺寸测量的光学系统不同，本文依据不同的液体具有不同的折射率，提出利用柱形容器中液体的聚光特性，得到两种不同液体的分界面在线阵ＣＣＤ上清晰的像。     

单幅同轴全息图两步迭代收缩重建

利用压缩传感理论中的两步迭代收缩重建算法,开展单幅同轴全息图重建实验研究,实现单幅同轴全息图共轭重建像的消除并克服数字全息技术在轴向聚焦平面识别能力的不足。以数字图像和标准分辨率板为记录物体,比较分析了基于两步迭代收缩算法和菲涅尔近似衍射重建算法的重建质量;以两根裸光纤为实验样本,分析了两步迭代收缩重建算法对记录物体轴向不同焦平面的识别能力。实验结果表明两步迭代收缩重建算法可得到清晰度高于68.73%的重建信息,同时对直径为125 m的两根光纤在9 mm的轴向间距条件下,显示出了比全息菲涅尔近似算法更好的聚焦平面识别能力。这一轴向聚焦识别能力有助于数字全息技术应用于功能材料梯度参数或功能涂层光学器件涂层厚度检测。     

基于MCPT解法器库的专用辐射探测模拟软件研发与应用北大核心CSCD

甲状腺内^(131)I放射性活度与辐射探测结果的比例关系与甲状腺几何尺寸、探测距离等因素相关,是估算甲状腺内^(131)I含量与其可能造成的辐照损伤的关键参数。基于MCPT辐射输运数值模拟算法器库开发了用于开展NaI探测器伽马辐射测量模拟的应用程序,进而建立了多组具有不同容积的甲状腺型容器和不同探测距离的物理模型,最终通过蒙特卡罗数值计算得到了不同测量状态下探测器的探测效率。在甲状腺型容器与探测器距离较远时,数值模拟给出的结果与理论计算结果一致,证明此应用程序可用于定量分析NaI的探测效率。数值模拟结果表明,小距离模型的结果受甲状腺样容器的大小和距离的显著影响,模拟给出的探测效率表为开展深入细致的实验研究奠定了基础。     

Measurement of Solid-gas Two-phase Flow using Optical Fiber Sensor

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Splitting an Arbitrary Three-Qubit State via a Five-Qubit Cluster State and a Bell State

Quantum information splitting (QIS) provides an idea for transmitting the quantum state through a classical channel and a preshared quantum entanglement resource. This paper presents a new scheme for QIS based on a five-qubit cluster state and a Bell state. In this scheme, the sender transmits the unknown three-qubit secret state to two agents by the quantum channel with the Bell basis measurement three times and broadcasts the measurement results to the agents through the classical channel. The agent who restores the secret state can successfully recover the initial information to be transmitted through the appropriate unitary operation with the help of the other party. Firstly, our scheme’s process can be accurately realized by performing the applicable Bell basis measurement, single-qubit measurement, and local unitary operation instead of a multiparticle joint measurement. The splitting process of quantum information is realized through a convenient operation. Secondly, compared with some previous schemes, the efficiency of the total scheme has been improved in principle, and the qubit consumption is reduced. Finally, the security of the quantum information splitting scheme is analyzed from the perspectives of external attacks and participant attacks. It is proved that our scheme can effectively resist internal participant attacks and external eavesdropper attacks.     

Theorie und Optimierung der radiometrischen Absorptionsmethode zur Analyse von Binärsystemen

Die Arbeit behandelt theoretisch das Auflösungsvermögen der Absorptionsmethode zur Analyse von Binārsystemen bei Anwendung von monoenergetischer Gamma- und Rötgenstrahlung. Es wird eine analytische Beziehung für die Funktion Δp abgeleitet, die die kleinstmöglichen Veränderung in der Zusammensetzung des Systems chgarakterisiert und die wir noch mittelts dieser Methode in Abhängigkeit von allen zu berückischtigenden Faktoren bestimmen könne. Aus den Extremwerten der Funktion Δp werden dann die optimalen Werte der Energine, der Schichtdicke, der Strahlungshäufigkeit und die Optimalwerte der restlichen Parameter so bestimmt, daβ das Auflösungsvermögen der Methode maximal ist. Die Theorie wird auf eine Ag-Cu-Legierung angewendet.     

Velocity measurement for moving surfaces using spatial filtering method based on area image sensor

The idea of using spatial filtering method to measure velocity of vehicles for an inertial navigation system is put forward. Corresponding optical system, including a 532 nm solid-state laser as active illumination, is established. A 17.92 mm × 14.34 mm area charge coupled device (CCD) is employed both as detector and as spatial filter. The spatial filtering characteristics are theoretically analyzed using a power spectral density function. The spatial filtering operation of CCD is performed fully by software. Therefore, the parameters of the spatial filter, such as the size and the number of spatial period, are changeable. In addition, the CCD is arranged as two differential spatial filters without any other additional elements. Experiments are carried out to examine the feasibility of CCD as two differential spatial filters and the influence of the number of spatial period on the signal frequency. The results indicate that the more number of spatial period the more accurate measurements can be obtained, and show that the relation between signal frequency and velocity has good linearity. So this velocimeter is suitable to provide velocity information for a vehicle self-contained inertial navigation system.