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Congruences for finite triple harmonic sums

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 946-948页

作者： FU Xu-dan ZHOU Xia cai tian-xin Department of Mathematics Zhejiang University Hangzhou 310028 China Hangzhou Foreign Language School Hangzhou 310023 China

Zhao （2003a） first established a congruence for any odd prime p〉3, S（1,1,1 ;p）=-2Bp-3 （mod p）, which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S（α,β, γ,ρ）（modp） is considered for all positive integers α,β, γ. We refer to w=α＋β＋ γ as the weight of the sum, and show that if w is even, S（α,β, γ,ρ）=0 （mod p） for p≥w＋3; if w is odd, S（α,β, γ,ρ）=-rBp-w （mod p） for p≥w, here r is an explicit rational number independent ofp. A congruence of Catalan number is obtained as a special case.

关键词： Finite triple harmonic sums Recursive relation Bernoulli numbers Catalan numbers

Quantum state manipulation of single-Cesium-atom qubit in a micro-optical trap

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Frontiers of physics 2014年第5期9卷 634-639页

作者： Zhi-Hui Wang Gang Li Ya-Li tian tian-cai Zhang State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan 030006 China

Based on single Cesium atoims trapped in a 1064 nm microscopic optical trap we have exhibited a single qubit encoded in the Cesium ＂clock states＂. The single qubit initialization, detection and the fast state rotation with high efficiencies are demonstrated and this state manipulation is crucial for quantmn information processing. The ground ~ates Rabi flopping rate of 229.0 ± 0.6 kHz is realized hy a two-photon Raman process. A clock states dephasing time of 3.0 ± 0.7 ms is measured, while all irreversible homogeneous dephasing time of 124 ± 17 ms is achieved by using the spin-echo technique. This well-controlled single atom provides an ideal quantmn qubit and quantmn node for quantum information processing.

关键词： qubit single atom Rabi flopping spin-echo dephasing time

A Durable Catalyst for Vapor Phase Nitration of Benzene with Nitric Acid

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Chinese Chemical Letters 2002年第10期13卷 1013-1016页

作者： Peng ZHOU Xin Ping WANG tian Xi cai State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116012

Experimental results in this work demonstrate that PW12-H2SO4/SiO2 catalyst is a good and durable catalyst for vapor phase nitration of benzene to nitrobenzene (NB) using 65% nitric acid at normal pressure. It retains the advantages of using H2SO4 as catalyst and the addition of phosphotungstic acid holds back the effusion of sulfuric acid. This new catalyst keeps high activity (the conversion of HNO3 is more than 92%), high selectivity of NB (more than 97%) and high space time yield (STY 1.5 kg NB/kg cat.h) even after 150 h on stream, under condition of 423 K, SV=3200 ml/g h.

关键词： Nitration benzene solid acid nitric acid nitrobenzene.

Adaptive Variable Structure Control of MIMO Nonlinear Systems with Time-varying Delays and Unknown Dead-zones

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International Journal of Automation and computing 2009年第2期6卷 124-136页

作者： tian-Ping Zhang cai-Ying Zhou Qing Zhu Department of Automation College of Information Engineering Yangzhou University Yangzhou 225009 PRC

In this paper, adaptive variable structure neural control is presented for a class of uncertain multi-input multi-output （MIMO） nonlinear systems with state time-varying delays and unknown nonlinear dead-zones. The unknown time-varying delay uncer- tainties are compensated for using appropriate Lyapunov-Krasovskii functionals in the design. The approach removes the assumption of linear function outside the deadband without necessarily constructing a dead-zone inverse as an added contribution. By utilizing the integral-type Lyapunov function and introducing an adaptive compensation term for the upper bound of the residual and optimal approximation error as well as the dead-zone disturbance, the closed-loop control system is proved to be semi-globally uniformly ultimately bounded. In addition, a modified adaptive control algorithm is given in order to avoid the high-frequency chattering phenomenon. Simulation results demonstrate the effectiveness of the approach.

关键词： Adaptive control neural networks (NNs) variable structure control dead-zone nonlinear time-varying delay systems.

Effect of Ni Loading on the Catalytic Properties of Molybdenum Oxides for the Isomerization of Heptane

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Chinese Chemical Letters 2002年第2期13卷 177-180页

作者： Ying Jun WANG Xin Ping WANG tian Xi cai State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116012

The catalytic properties of MoOx and incorporation Ni onto the MoOx for the isomerization of heptane have been investigated under atmospheric pressure at different conditions such as different flow rate of H2, different reaction temperature etc.. Compared with MoOx, the Ni addition to the MoOx markedly improved the isomerization activity of heptane by improving the reducibility of MoO3 and activation of H2 in reaction.

关键词： Molybdenum oxides nickel isomerization heptane.

Thermal–hydraulic analysis of space nuclear reactor TOPAZ-Ⅱ with modified RELAP5

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Nuclear Science and Techniques 2019年第1期30卷 121-131页

作者： Cheng-Long Wang tian-cai Liu Si-Miao Tang Wen-Xi tian Sui-Zheng Qiu Guang-Hui Su Department of Nuclear Science and Technology Xi'an Jiaotong University China Institute of Atomic Energy

With the advantages of high reliability, power density, and long life, nuclear power reactors have become a promising option for space power. In this study, the Reactor Excursion and Leak Analysis Program 5(RELAP5), with the implementation of sodium–potassium eutectic alloy(NaK-78) properties and heat transfer correlations, is adopted to analyze the thermal–hydraulic characteristics of the space nuclear reactor TOPAZ-Ⅱ.A RELAP5 model including thermionic fuel elements(TFEs), reactor core, radiator, coolant loop, and volume accumulator is established. The temperature reactivity feedback effects of the fuel, TFE emitter, TFE collector,moderator, and reactivity insertion effects of the control drums and safety drums are considered. To benchmark the integrated TOPAZ-Ⅱ system model, an electrical ground test of the fully integrated TOPAZ-Ⅱ system, the V-71 unit,is simulated and analyzed. The calculated coolant temperature and system pressure are in acceptable agreement with the experimental data for the maximum relative errors of 8 and 10%, respectively. The detailed thermal–hydraulic characteristics of TOPAZ-Ⅱ are then simulated and analyzed at the steady state. The calculation results agree well with the design values. The current work provides a solid foundation for space reactor design and transient analysis in the future.

关键词： Space nuclear reactor TOPAZ-Ⅱ Thermal–hydraulic analysis RELAP5 modification

Single-photon source with sub-MHz linewidth for cesium-based quantum information processing

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Frontiers of physics 2023年第6期18卷 275-281页

作者： Hai He Peng-Fei Yang Peng-Fei Zhang Gang Li tian-cai Zhang State Key Laboratory of Quantum Optics and Quantum Optics Devices Collaborative Innovation Center of Extreme OpticsInstitute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China

A single-photon source with narrow bandwidth,high purity,and large brightness can efficiently interact with material qubits strongly coupled to an optical microcavity for quantum information ***,we experimentally demonstrate a degenerate doubly resonant single-photon source at 852 nm by the cavity-enhanced spontaneous parametric downconversion process with a 100%duty cycle of *** single photon source possesses both high purity with a second-order correlation g^((2))_(h)(0)=0.021 and narrow linewidth with△_(V_(sp))=(800±13)*** single-photon s Single-photon source with sub-MHz linewidth for cesium-based quantum information processingource is compatible with the cesium atom D2 line and can be used for cesium-based quantum information processing Single-photon source with sub-MHz linewidth for cesium-based quantum information processing0.021.

关键词： single-photon source sub-MHz linewidth few longitudinal modes quantum information processing

Influence of pump intensity on atomic spin relaxation in a vapor cell

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Chinese Physics B 2019年第11期28卷 339-343页

作者： Chen Yang Guan-Hua Zuo Zhuang-Zhuang tian Yu-Chi Zhang tian-cai Zhang State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China College of Physics and Electronics Engineering Shanxi UniversityTaiyuan 030006China

Atomic spin relaxation in a vapor cell, which can be characterized by the magnetic resonance linewidth(MRL),is an important parameter that eventually determines the sensitivity of an atomic magnetometer. In this paper, we have extensively studied how the pump intensity affects the spin relaxation. The experiment is performed with a cesium vapor cell, and the influence of the pump intensity on MRL is measured at room temperature at zero-field resonance. A simple model with five atomic levels of a Λ-like configuration is discussed theoretically, which can be used to represent the experimental process approximately, and the experimental results can be explained to some extent. Both the experimental and the theoretical results show a nonlinear broadening of the MRL when the pump intensity is increasing. The work helps to understand the mechanism of pump induced atomic spin relaxation in the atomic magnetometers.

关键词： atomic magnetometer atomic spin relaxation optical pumping

Direct Oxidation of Ethene to Acetic Acid

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Chinese Chemical Letters 2001年第2期12卷 125-126页

作者： Ke Gong FANG Xin Ping WANG Jian Lu ZHANG tian Xi cai State Key Laboratory of Dye and Surfactant Fine Chemicals Dalian University of Technology Dalian 116012

Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained w... 详细信息

关键词： Pd-SiW12/SiO2 catalyst acetic acid production ethene oxidation.