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A Temperature-Autocompensated Detecting Circuit for the Capacitance Fuze
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作者 邓甲昊 周勇 +2 位作者 程受浩 刘华 施聚生 《Journal of Beijing Institute of Technology》 EI CAS 1993年第1期74-82,共9页
In view of drastic possible changes in fuze environment tempera- ture,a kind of temperature autocompensated detecting circuit for the capaci- tance fuze is proposed.It provides a steady detected output when the envi- ... In view of drastic possible changes in fuze environment tempera- ture,a kind of temperature autocompensated detecting circuit for the capaci- tance fuze is proposed.It provides a steady detected output when the envi- ronment temperature varies from-50℃ to 65℃ and keeps a stable detecting sensitivity.Based on an analysis of the circuit,influence of the major param- eters of the oscillating circuit on the amplitude are explored.A few impor- tant controllable parameters affecting the circuit feature are found out.A parameter-control method is given in order to improve the circuit perfor- mance. 展开更多
关键词 capacitance fuze detecting circuit circuit analysis/parameter analysis
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Density Matrix for Mesoscopic Distributed Parameter Circuits
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作者 JIYing-Hua WANGQi LUOHai-Mei LEIMin-Sheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3期547-550,共4页
Under the Born-von-Karmann periodic boundary condition, we propose a quantization scheme for non-dissipative distributed parameter circuits (i.e. a uniform periodic transmission line). We find the unitary operator for... Under the Born-von-Karmann periodic boundary condition, we propose a quantization scheme for non-dissipative distributed parameter circuits (i.e. a uniform periodic transmission line). We find the unitary operator for diagonalizing the Hamiltonian of the uniform periodic transmission line. The unitary operator is expressed in a coordinate representation that brings convenience to deriving the density matrix rho(q,q',beta). The quantum fluctuations of charge and current at a definite temperature have been studied. It is shown that quantum fluctuations of distributed parameter circuits, which also have distributed properties, are related to both the circuit parameters and the positions and the mode of signals and temperature T. The higher the temperature is, the stronger quantum noise the circuit exhibits. 展开更多
关键词 mesoscopic distributed parameter circuits density matrix quantum fluctuations
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Quantum state measurement in double quantum dots with a radio-frequency quantum point contact
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作者 严蕾 王海霞 +1 位作者 殷雯 王芳卫 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第2期87-92,共6页
We study the dynamics of two electron spins in coupled quantum dots (CQDs) monitored by a quantum point contact (QPC) detector. Their quantum state can be measured by embedding the QPC in an LC circuit. We derive ... We study the dynamics of two electron spins in coupled quantum dots (CQDs) monitored by a quantum point contact (QPC) detector. Their quantum state can be measured by embedding the QPC in an LC circuit. We derive the Bloch-type rate equations of the reduced density matrix for CQDs. Special attention is paid to the numerical results for the weak measurement condintion under a strong Coulomb interaction. It is shown that the evolution of QPC current always follows that of electron occupation in the right dot. In addition, we find that the output voltage of the circuit can reflect the evolution of QPC current when the circuit and QPC are approximately equal in frequency. In particular, the wave shape of the output voltage can be improved by adjusting the circuit resonance frequency and bandwidth. 展开更多
关键词 MEASUREMENT quantum state output voltage circuit parameter
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Analyzing the response of a contactless conductivity detector in capillary electrophoresis by a resonant method
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作者 Qi Kang Qing Zhang +2 位作者 Yao Long Li Dong Dong Li Da Zhong Shen 《Chinese Chemical Letters》 SCIE CAS CSCD 2012年第7期831-834,共4页
We report a resonant method to measure the wall capacitance(C_w) and solution resistance(R_S) in a capacitively coupled contactless conductivity detector(C^4D).Under the typical operating conditions in capillary... We report a resonant method to measure the wall capacitance(C_w) and solution resistance(R_S) in a capacitively coupled contactless conductivity detector(C^4D).Under the typical operating conditions in capillary electrophoresis(I.D.50μm,O.D. 360μm,electrode length of 4 mm,electrode gap of 1 mm,frequency of 200 kHz),the values of C_w measured in 1 and 20 mmol/L NaCl solutions are 2.8 and 32 fF,which are only 1.1%and 12%of prediction by the equation in references,respectively.The value of R_S is less than the prediction in solutions withκ〈0.02 S/m.The response current of C^4D is due to the change in C_w because the total impedance of a C^4D is composed mainly by the impedance from C_w. 展开更多
关键词 Contactless conductivity detector Equivalent circuit parameter Quartz crystal resonator Resonant method
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Variational quantum semi-supervised classifier based on label propagation
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作者 侯艳艳 李剑 +1 位作者 陈秀波 叶崇强 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期279-289,共11页
Label propagation is an essential semi-supervised learning method based on graphs,which has a broad spectrum of applications in pattern recognition and data mining.This paper proposes a quantum semi-supervised classif... Label propagation is an essential semi-supervised learning method based on graphs,which has a broad spectrum of applications in pattern recognition and data mining.This paper proposes a quantum semi-supervised classifier based on label propagation.Considering the difficulty of graph construction,we develop a variational quantum label propagation(VQLP)method.In this method,a locally parameterized quantum circuit is created to reduce the parameters required in the optimization.Furthermore,we design a quantum semi-supervised binary classifier based on hybrid Bell and Z bases measurement,which has a shallower circuit depth and is more suitable for implementation on near-term quantum devices.We demonstrate the performance of the quantum semi-supervised classifier on the Iris data set,and the simulation results show that the quantum semi-supervised classifier has higher classification accuracy than the swap test classifier.This work opens a new path to quantum machine learning based on graphs. 展开更多
关键词 semi-supervised learning variational quantum algorithm parameterized quantum circuit
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Towards an efficient variational quantum algorithm for solving linear equations
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作者 WenShan Xu Ri-Gui Zhou +1 位作者 YaoChong Li XiaoXue Zhang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2024年第11期54-65,共12页
Variational quantum algorithms are promising methods with the greatest potential to achieve quantum advantage,widely employed in the era of noisy intermediate-scale quantum computing.This study presents an advanced va... Variational quantum algorithms are promising methods with the greatest potential to achieve quantum advantage,widely employed in the era of noisy intermediate-scale quantum computing.This study presents an advanced variational hybrid algorithm(EVQLSE)that leverages both quantum and classical computing paradigms to address the solution of linear equation systems.Initially,an innovative loss function is proposed,drawing inspiration from the similarity measure between two quantum states.This function exhibits a substantial improvement in computational complexity when benchmarked against the variational quantum linear solver.Subsequently,a specialized parameterized quantum circuit structure is presented for small-scale linear systems,which exhibits powerful expressive capabilities.Through rigorous numerical analysis,the expressiveness of this circuit structure is quantitatively assessed using a variational quantum regression algorithm,and it obtained the best score compared to the others.Moreover,the expansion in system size is accompanied by an increase in the number of parameters,placing considerable strain on the training process for the algorithm.To address this challenge,an optimization strategy known as quantum parameter sharing is introduced,which proficiently minimizes parameter volume while adhering to exacting precision standards.Finally,EVQLSE is successfully implemented on a quantum computing platform provided by IBM for the resolution of large-scale problems characterized by a dimensionality of 220. 展开更多
关键词 quantum computing variational quantum algorithm systems of linear equations parameterized quantum circuit
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Analysis of learnability of a novel hybrid quantum-classical convolutional neural network in image classification
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作者 程涛 赵润盛 +2 位作者 王爽 王睿 马鸿洋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期275-283,共9页
We design a new hybrid quantum-classical convolutional neural network(HQCCNN)model based on parameter quantum circuits.In this model,we use parameterized quantum circuits(PQCs)to redesign the convolutional layer in cl... We design a new hybrid quantum-classical convolutional neural network(HQCCNN)model based on parameter quantum circuits.In this model,we use parameterized quantum circuits(PQCs)to redesign the convolutional layer in classical convolutional neural networks,forming a new quantum convolutional layer to achieve unitary transformation of quantum states,enabling the model to more accurately extract hidden information from images.At the same time,we combine the classical fully connected layer with PQCs to form a new hybrid quantum-classical fully connected layer to further improve the accuracy of classification.Finally,we use the MNIST dataset to test the potential of the HQCCNN.The results indicate that the HQCCNN has good performance in solving classification problems.In binary classification tasks,the classification accuracy of numbers 5 and 7 is as high as 99.71%.In multivariate classification,the accuracy rate also reaches 98.51%.Finally,we compare the performance of the HQCCNN with other models and find that the HQCCNN has better classification performance and convergence speed. 展开更多
关键词 parameterized quantum circuits quantum machine learning hybrid quantum-classical convolutional neural network
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An Efficient Approach for the Numerical Identification of R and L Parameters of High Frequency Multi-winding Transformers
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作者 Z. De Greve O. Deblecker J. Lobry 《Journal of Energy and Power Engineering》 2011年第7期641-650,共10页
In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element (FE) computations. Lumped parameter models are first presented, based on previously published w... In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element (FE) computations. Lumped parameter models are first presented, based on previously published work. All parameters of these circuits can be interpreted as the results of open and short-circuit tests on the transformer. Based on this consideration, numerical procedures are then proposed to derive frequency-dependent lumped parameters from FE simulations. By using an adequate formulation, parameters are directly obtained from the FE model degrees of freedom, without performing any volume integration in post-processing, which can be source of numerical errors. In this contribution, attention is paid on the modeling of magnetic coupling using inductances, and dissipative effects (winding and core losses) using resistances. The impact of conductor eddy currents on the circuit parameters is moreover studied in details. Instead of an analysis of the impact conductor eddy currents may have on the circuit parameters is moreover carried through. 展开更多
关键词 Multi-winding transformer finite elements lumped parameter circuits.
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Quantum classifier with parameterized quantum circuit based on the isolated quantum system
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作者 Shi Jinjing Wang Wenxuan +2 位作者 Xiao Zimeng Mu Shuai Li Qin 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2022年第4期21-31,共11页
It is a critical challenge for quantum machine learning to classify the datasets accurately.This article develops a quantum classifier based on the isolated quantum system(QC-IQS)to classify nonlinear and multidimensi... It is a critical challenge for quantum machine learning to classify the datasets accurately.This article develops a quantum classifier based on the isolated quantum system(QC-IQS)to classify nonlinear and multidimensional datasets.First,a model of QC-IQS is presented by creating parameterized quantum circuits(PQCs)based on the decomposing of unitary operators with the Hamiltonian in the isolated quantum system.Then,a parameterized quantum classification algorithm(QCA)is designed to calculate the classification results by updating the loss function until it converges.Finally,the experiments on nonlinear random number datasets and Iris datasets are designed to demonstrate that the QC-IQS model can handle and generate accurate classification results on different kinds of datasets.The experimental results reveal that the QC-IQS is adaptive and learnable to handle different types of data.Moreover,QC-IQS compensates the issue that the accuracy of previous quantum classifiers declines when dealing with diverse datasets.It promotes the process of novel data processing with quantum machine learning and has the potential for more comprehensive applications in the future. 展开更多
关键词 quantum classifier quantum classification isolated quantum system parameterized quantum circuit HAMILTONIAN
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Equivalent Source Method Approachto Compositely Postsina Rectangular Waveguide
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作者 Cao Wei AND Long Bing(Department of Radio Engineering ,Nanjing University ofPosts and Telecommunications , Nanjing 210003 , P. R. China ) 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 1994年第2期23-29,共7页
The campontely structured inductive waveguide elements are analyzed by making use ofthe equivalent source method in this paper The number and cross section of the inductive posts are arbi-trary, and they are of rither... The campontely structured inductive waveguide elements are analyzed by making use ofthe equivalent source method in this paper The number and cross section of the inductive posts are arbi-trary, and they are of rither pure metallic or pure dielectric lype , or composed of both metallic and di-electric ones. A number of inductive waveguide elements are numerically analyzed and a good agree-ment is achieved in comiparison with the measured data or results available in published literalures. 展开更多
关键词 waveguide element inductive post equivalent source method equivalent circuit parame-ter scattering parameter.
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