真正的经典复刻Musical Fidelity A1纯A类合并式功放重现江湖

毫无疑问,英国是这个星球上音响文化底蕴最深厚的国家之一,这里孕育了众多著名的音响品牌,其中音响爱好者所熟知的Musical Fidelity便是夜夜者之一。Musical Fidelity创立于1982年,至今已有超过40年的历史,其创始人为Antony Michaelson先生。Musical Fidelity的中文名为“音乐传真”,这个名字不仅悦耳动听,还蕴含着深刻的意义。

A Quantum Tanimoto Coefficient Fidelity for Entanglement Measurement

Fidelity plays an important role in quantum information processing,which provides a basic scale for comparing two quantum states.At present,one of the most commonly used fidelities is Uhlmann-Jozsa(U-J)fidelity.However,U-J fidelity needs to calculate the square root of the matrix,which is not trivial in the case of large or infinite density matrices.Moreover,U-J fidelity is a measure of overlap,which has limitations in some cases and cannot reflect the similarity between quantum states well.Therefore,a novel quantum fidelity measure called quantum Tanimoto coefficient(QTC)fidelity is proposed in this paper.Unlike other existing fidelities,QTC fidelity not only considers the overlap between quantum states,but also takes into account the separation between quantum states for the first time,which leads to a better performance of measure.Specifically,we discuss the properties of the proposed QTC fidelity.QTC fidelity is compared with some existing fidelities through specific examples,which reflects the effectiveness and advantages of QTC fidelity.In addition,based on the QTC fidelity,three discrimination coefficients d_(1)^(QTC),d_(2)^(QTC),and d_^(3)^(QTC)are defined to measure the difference between quantum states.It is proved that the discrimination coefficient d_(3)^(QTC)is a true metric.Finally,we apply the proposed QTC fidelity-based discrimination coefficients to measure the entanglement of quantum states to show their practicability.

High-fidelity topological quantum state transfers in a cavity-magnon system

We propose a scheme for realizing high-fidelity topological state transfer via the topological edge states in a onedimensional cavity-magnon system.It is found that the cavity-magnon system can be mapped analytically into the generalized Su-Schrieffer-Heeger model with tunable cavity-magnon coupling.It is shown that the edge state can be served as a quantum channel to realize the photonic and magnonic state transfers by adjusting the coupling strength between adjacent cavity modes.Further,our scheme can realize the quantum state transfer between photonic state and magnonic state by changing the cavity-magnon coupling strength.With the numerical simulation,we quantitatively show that the photonic,magnonic and magnon-to-photon state transfers can be achieved with high fidelity in the cavity-magnon system.Spectacularly,three different types of quantum state transfer schemes can be even transformed into each other in a controllable fashion.The Su-Schrieffer-Heeger model based on the cavity-magnon system provides us a tunable platform to engineer the transport of photon and magnon,which may have potential applications in topological quantum processing.

Quantum Codes Do Not Increase Fidelity against Isotropic Errors

In this article, we study the ability of error-correcting quantum codes to increase the fidelity of quantum states throughout a quantum computation. We analyze arbitrary quantum codes that encode all qubits involved in the computation, and we study the evolution of n-qubit fidelity from the end of one application of the correcting circuit to the end of the next application. We assume that the correcting circuit does not introduce new errors, that it does not increase the execution time (i.e. its application takes zero seconds) and that quantum errors are isotropic. We show that the quantum code increases the fidelity of the states perturbed by quantum errors but that this improvement is not enough to justify the use of quantum codes. Namely, we prove that, taking into account that the time interval between the application of the two corrections is multiplied (at least) by the number of qubits n (due to the coding), the best option is not to use quantum codes, since the fidelity of the uncoded state over a time interval n times smaller is greater than that of the state resulting from the quantum code correction.

基于Wireless Fidelity的智能开关机的设计

本课题源于对生活中各种生活电器智能开关机的实际需求而设计开发的,基于人与现代技术的融合理念,主要以单片机为所有器件的控制中心,设计中使用各类传感器来收集相关信息,如用温度传感器收集温度信息,用光敏传感器收集家居环境中的光亮程度等。该设计设置了手动和自动两个模式,可用于普通家庭、单位办公室和各类教室等各种场所来控制各种常用电器,如风扇、灯具、空调等。

Near-perfect fidelity polarization-encoded multilayer optical data storage based on aligned gold nanorods

Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.

Fidelity of the APHRODITE Dataset in Representing Extreme Precipitation over Central Asia

Using rain-gauge-observation daily precipitation data from the Global Historical Climatology Network(V3.25)and the Chinese Surface Daily Climate Dataset(V3.0),this study investigates the fidelity of the AHPRODITE dataset in representing extreme precipitation,in terms of the extreme precipitation threshold value,occurrence number,probability of detection,and extremal dependence index during the cool(October to April)and warm(May to September)seasons in Central Asia during 1961–90.The distribution of extreme precipitation is characterized by large extreme precipitation threshold values and high occurrence numbers over the mountainous areas.The APHRODITE dataset is highly correlated with the gauge-observation precipitation data and can reproduce the spatial distributions of the extreme precipitation threshold value and total occurrence number.However,APHRODITE generally underestimates the extreme precipitation threshold values,while it overestimates the total numbers of extreme precipitation events,particularly over the mountainous areas.These biases can be attributed to the overestimation of light rainfall and the underestimation of heavy rainfall induced by the rainfall distribution–based interpolation.Such deficits are more evident for the warm season than the cool season,and thus the biases are more pronounced in the warm season than in the cool season.The probability of detection and extremal dependence index reveal that APHRODITE has a good capability of detecting extreme precipitation,particularly in the cool season.

Preserving entanglement and the fidelity of three-qubit quantum states undergoing decoherence using weak measurement

We demonstrate a method to preserve entanglement and improve fidelity of three-qubit quantum states undergoing amplitude-damping decoherence using weak measurement and quantum measurement reversal. It is shown that we are able to enhance entanglement to the greatest extent, and to circumvent entanglement sudden death by increasing the weak measurement strength both for the GHZ state and the W state. The weak measurement technique can also enhance the fidelity to the quantum region and even close to 1 for the whole range of the decoherence parameter in both of the two cases. In addition, the W state can maintain more fidelity than the GHZ state in the protection protocol. However, the GHZ state has a higher success probability than the W state.

Fidelity of quantum information for V-type three-level atom interacting with a number state light field in Kerr medium

In this paper the evolution characteristics of the fidelity of quantum information for the V-type three-level atom interacting with number state light field in Kerr meddium are investigated. It shows that the periodicity of the evolutions of fidelity of quantum information is influenced by the Kerr coefficient, the photon number of the initial field and intensity of light. The evolutions of the fidelity of quantum information are modulated by the initial number state field. The Rabi oscillation frequency and the modulation frequency of fidelity for the field and the system vary with the value of the Kerr coefficient. The evolutions of fidelity of quantum information obviously show the quantum collapse and revival behaviours in the system of atom interacting with light field.

Novel image restoration model coupling gradient fidelity term based on adaptive total variation

A novel image restoration model coupling with a gradient fidelity term based on adaptive total variation is proposed in this paper. In order to choose proper parameters, the selection criteria were analyzed theoretically, and a simple scheme to demonstrate its validity was adopted experimentally. To make fair comparisons of performances of three models, the same numerical algorithm was used to solve partial differential equations. Both the international standard test image on Lena and HR image of CBERS-02B of Dalian city were used to verify the performance of the model. Experimental results illustrate that the new model not only preserved the edge and important details but also alleviated the staircase effect effectively.

Entanglement fidelity of channel adaptive quantum codes

We study the performances of quantum channel adaptive [4,1] code transmitting in a joint amplitude damping and dephasing channel, the [6,2] code transmitting in an amplitude damping channel by combining the encoding, noise process, and decoding as one effective channel. We explicitly obtain the entanglement fidelities. The recovery operators of the [6,2] code are given. The performance is nearly optimal compared with that of the optimal method of semidefinite programming.

<i>In Vitro</i>Propagation of Ocimum Gratissimum L. (Lamiaceae) and Its Evaluation of Genetic Fidelity Using RAPD Marker

An efficient plant propagation system through nodal explants was established in Ocimum gratissimum L, a medicinally important herbaceous perennial herb belonging to the family Lamiaceae. Axillary shoot bud proliferation was initiated from nodal explants cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of N6-benzyladenine (BA) (0.5 - 3.0 mg/l), Kinetin (KN) (0.5 - 3.0 mg/l) and 2-isoPentenyladenine (2-iP) (0.5 - 3.0 mg/l). Maximum numbers of shoots (5.17 ± 0.04) with average length (2.50 ± 0.07) were induced on medium containing 1.0 mg/l BA. Shoot multiplication was maintained by repeated subculturing the original nodal explants on shoot multiplication medium after each harvest of newly formed shoots. Histological study shows that the organogenesis occurs directly, without callus formation on epidermal and sub epidermal layer of the explants. Rooting of shoots was achieved on half strength MS medium supplemented with 1.5 mg/1 Indole-3-butyric acid (IBA) and 2% sucrose. Well-developed complete plantlets were transferred to plastic pots containing a mixture of (1:1) soil and vermiculite showed 82.5 % survival rate. Genetic fidelity was assessed by chromosome analysis and DNA fingerprinting using random amplified polymorphic DNA (RAPD) of in vitro and in vivo plants. Nine arbitrary decamers displayed same banding profile showed no genomic alterations, indicating homogeneity among the tissue culture regenerates and genetic uniformity with that of donor plants. The present study provides high fidelity micro-propagated system for efficient and rapid micro-propagation protocol of this important medicinal plant and great use in conserving without risk of genetic instability.

Variable Fidelity Surrogate Assisted Optimization Using A Suite of Low Fidelity Solvers

Variable-fidelity optimization (VFO) has emerged as an attractive method of performing, both, high-speed and high-fidelity optimization. VFO uses computationally inexpensive low-fidelity models, complemented by a surrogate to account for the difference between the high-and low-fidelity models, to obtain the optimum of the function efficiently and accurately. To be effective, however, it is of prime importance that the low fidelity model be selected prudently. This paper outlines the requirements for selecting the low fidelity model and shows pitfalls in case the wrong model is chosen. It then presents an efficient VFO framework and demonstrates it by performing transonic airfoil drag optimization at constant lift, subject to thickness constraints, using several low fidelity solvers. The method is found to be efficient and capable of finding the optimum that closely agrees with the results of high-fidelity optimization alone.

基于Light Fidelity技术在智慧城市的应用

本文以LightFidelity展趋势和概念为基础,通过研究LightFidelity技术在智慧城市的应用,以推动智慧城市建设。LightFidelity是一种以白光LED为基础的新型无线通信技术,主流的可见光通信系统采用光正交频分复用(O-OFDM)技术来实现,该技术可以使受到干扰的信号仍然能被可靠地接收,信号的频带利用率也大幅提高,非对称限幅光正交频分复用(ACO-OFDM)调制使得O-OFDM技术完全适用于可见光通信。本文讨论滤波器组多载波(FBMC)与O-OFDM在Light Fidelity通信过程中的性能对比,通过理论分析结合仿真说明具体分析,探讨FBMC及O-OFDM在通信过程中的指标比对,由此证明采用O-OFDM在Light Fidelity通信中的优越性。

Fidelity of Interference Between Two Bose-Einstein Condensates with Collision and Dissipation

Interference between the two Bose-Einstein condensates with collision and dissipation is investigated. Itis found that when the two condensates are initially in the coherent state, the interference intensity is affected by thecollision and dissipation, but for the initial Fock state, it is only related to the dissipation. Whether the initial stateis in the coherent state or in a Fock state, the fidelity time has nothing to do with collision. For the initial coherentstate, the fidelity loss rate is zero, but for the initial Fock state, it is determined by the initial particle number of thetwo condensates and dissipation.

Average fidelity estimation of twirled noisy quantum channel using unitary 2t-design

We propose a method to estimate the average fidelity using the unitary 2t-design of a twirled noisy channel, which is suitable for large-scale quantum circuits. Compared with the unitary 2-design in randomized benchmarking, the unitary2t-design for the twirling of noisy channels is more flexible in construction and can provide more information. In addition,we prove that the proposed method provides an efficient and reliable estimation of the average fidelity in benchmarking multistage quantum gates and estimating the weakly gate-and time-dependent noise. For time-dependent noise, we provide a scheme of moment superoperator to analyze the noise in different experiments. In particular, we give a lower bound on the average fidelity of a channel with imperfect implementation of benchmarking and state preparation and measurement errors(SPAM).

Alternative non-Gaussianity measures for quantum states based on quantum fidelity

We propose three alternative measures for non-Gaussianity of quantum states: sine distance, Bures angle, and Bures distance, which are based on quantum fidelity introduced by Wang [Phys. Lett. A 373 58(2008)]. Using them, we evaluate the non-Gaussianity of some relevant single-mode and two-mode non-Gaussian states and find a good consistency of the three examined measures. In addition, we show that such metrics can exactly quantify the degree of Gaussianity of even Schrödinger-cat-like states of small amplitudes that can not be measured by other known non-Gaussianity measures such as the Hilbert–Schmidt metric and the relative entropy metric. We make a comparative study between all existing nonGaussianity measures according to the metric axioms and point out that the sine distance is the best candidate among them.

Fidelity of an electron in one-dimensional determined potentials

We numerically study the fidelity of an electron in the one-dimensional Harper model and in the one-dimensional slowly varying potential model. Our results show that many properties of the two models can be well reflected by the fidelity： （i） the mobility edge and metal-insulator transition can be characterized by the static fidelity; （ii） the extended state and localized state can be identified by the dynamic fidelity. Therefore, it may broaden the applied areas of the fidelity.

Fidelity between Gaussian mixed states with quantum state quadrature variances

In this paper, from the original definition of fidelity in a pure state, we first give a well-defined expansion fidelity between two Gaussian mixed states. It is related to the variances of output and input states in quantum information pro- cessing. It is convenient to quantify the quantum teleportation （quantum clone） experiment since the variances of the input （output） state are measurable. Furthermore, we also give a conclusion that the fidelity of a pure input state is smaller than the fidelity of a mixed input state in the same quantum information processing.

Sudden birth and sudden death of thermal fidelity in a two-qubit system

We study the energy level crossing and the thermal fidelity in a two-qubit system with the presence of a transverse inhomogeneous magnetic field.With the help of contour plots,we clearly identify the ground states of the system in different regions of parameter space,and discuss the corresponding energy level crossing.The fidelity between the ground state of the system and the state of the system at temperature T is calculated.The result shows that the fidelity is very sensitive to the magnetic field anisotropic factor,indicating that this factor may be used as a controller of the fidelity.The influence of the Yangian transition operators on the fidelity of the system is discussed.We find that the Yangian operators can change the fidelity dramatically and give rise to sudden birth and sudden death phenomena of the thermal fidelity.This makes the corresponding Yangian operators possible candidates for switchers to turn the fidelity on and off.