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Experimental demonstration of concatenated composite pulses robustness to non-static errors

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Science China(Physics,Mechanics & Astronomy) 2016年第9期59卷 46-51页

作者： Xing-long Zhen Tao Xin Fei-Hao Zhang Gui-Lu long State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua University Beijing 100084 China Innovation Centre of Quantum Matter Beijing 100084 China Tsinghua National Laboratory For Information Science and Technology Tsinghua University Beijing 100084 China

We examine the robustness of composite pulses to non-static classic noise in the NMR facility. Though these pulses are proposed to eliminate static, systematic errors, they are shown to be robust to time-varying noise with high-cut frequency up to near 10% of the Rabi frequency in a recent theoretical work. The CP pulses that are only robust to one kind of error have been implemented in various experiment platforms. In this paper we have compared the performance of reduced CinSK rc pulse, which is designed to cancel both the pulse length error and the off resonance error, to that of the primitive n pulse in a hybrid error environment. In order to achieve this target we have simultaneously injected noise to the RF output wave. The filter function formalism is employed to predict the evolution fidelity decay, which shows great consistency with the experiment data. Our work not only validates the superiority of reduced CinSK pulse but also indicates its sensitivity to the initial states, providing practical guidance in the noise suppression domain.

关键词： composite pulse filter function quantum control NMR

Numerical Investiga.ion on the Influence of Nozzle Lip Thickness on the Flow Field and Performance of an Annular Jet Pump

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Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 59-67页

作者： long-Zhou Xiao Xin-Ping long Xue-long Yang School of Power and Mechanical Engineering Wuhan University Key Lab of Jet Theory and New Technology of Hubei Province

The performance of an annular jet pump( AJP) is determined by its area ratio A( ratio of cross sectional area of throat and annular nozzle) and flow rate ratio q( ratio of primary and secondary flow rate,Qs/Qj),while the nozzle lip thickness is neglected in the present studies. This paper presents a study on the effect of the thickness on the flow field and performance of an AJP with A = 1. 75. With the increasing flow rate ratio and nozzle lip thickness,a small vortex forms at the nozzle lip and keeps on growing. However,as the flow rate ratio or nozzle lip thickness is extremely low,the vortex at the lip vanishes thoroughly. Moreover,the recirculation width varies conversely with the nozzle lip thickness when the flow rate ratio q ≤ 0. 13. While the deviation of the recirculation width with different nozzle lip thickness is negligible with q ≥ 0. 13. Additionally the existence of nozzle lip hinders the momentum exchange between the primary and secondary flow and leads to a mutation of velocity gradient near the nozzle exit,which shift the recirculation downstream. Finally,based on the numerical results of the streamwise and spanwise vortex distributions in the suction chamber, the characteristics of the mixing process and the main factors accounting for the AJP performance are clarified.

关键词： annular jet pump nozzle lip recirculation streamwise vortex spanwise vortex

Effect of the inclined weak interlayers on the rainfall response of a bedded rock slope

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Journal of Mountain Science 2016年第9期13卷 1663-1674页

作者： LI long-qi State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Environment and Civil Engineering Chengdu University of TechnologyChengdu 610059China

Engineering experience shows that outward dipping bedded rock slopes, especially including weak interlayers, are prone to slide under rainfall conditions. To investiga.e the effect of inclined weak interlayers at various levels of depth below the surface on the variation of displacements and stresses in bedded rock slopes, four geo- mechanical model tests with artificial rainfall have been conducted. Displacements, water content as well as earth pressure in the model were monitored by means of various FBG （Fiber Bragg Grating） sensors. The results showed that the amount of displacement of a slope with a weak interlayer is 2.8 to 6.2 times larger than that of a slope without a weak interlayer during one rainfall event. Furthermore, the position of the weak interlayer in terms of depth below the surface has a significant effect on the zone of deformation in the model. In the slope with a high position weak interlayer, the recorded deformation was larger in the superficial layer of the model and smaller in the frontal portion than in the slope with a low position weak interlayer. The slope with two weak interlayers has the largest deformation at all locations of all test slopes. The slope without a weak interlayer was only saturated in its superficial layer, while the displacement decreased with depth. That was different from all slopes with a weak interlayer in which the largest displacement shifted from the superficial layer to the weak interlayer when rainfall persisted. Plastic deformation of the weak interlayer promoted the formation of cracks which caused more water to flow into the slope, thus causing larger deformation in the slope with weak interlayers. In addition, the slide thrust pressure showed a vibration phenomenon o.5 to 1 hour ahead of an abrupt increase of the deformation, which was interpreted as a predictor for rainfall-induced failure of bedded rock slopes.

关键词： Bedded rock slope Inclined weakinterlayer Rainfall Model test

Hitting Probabilities and Fractal Dimensions of Multiparameter Multifractional Brownian Motion

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Acta Mathematica Sinica,English Series 2013年第9期29卷 1723-1742页

作者： Zhen long CHEN School of Statistics and Mathematics Zhejiang Gongshang University

The main goal of this paper is to study the sample path properties for the harmonisable-type N-parameter multifractional Brownian motion, whose local regularities change as time evolves. We provide the upper and lower bounds on the hitting probabilities of an （N, d）-multifractional Brownian motion. Moreover, we determine the Hausdorff dimension of its inverse images, and the Hausdorff and packing dimensions of its level sets.

关键词： Multifractional Brownian motion hitting probability inverse image level set Hausdorff dimension packing dimension

The Security of Using Large Language Models:A Survey With Emphasis on ChatGPT

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IEEE/CAA Journal of Automatica Sinica 2025年第1期 1-26页

作者： Wei Zhou Xiaoga.g Zhu Qing-long Han Lin Li Xiao Chen Sheng Wen Yang Xiang the School of Science Computing and Engineering Technologies Swinburne University of Technology IEEE the School of Computer and Mathematical Sciences the University of Adelaide Adelaide the Faculty of Science and Engineering Southern Cross University the School of Information and Physical Sciences the University of Newcastle

ChatGPT is a powerful artificial intelligence(AI)language model that has demonstrated significant improvements in various natural language processing(NLP) tasks. However, like any technology, it presents potential security risks that need to be carefully evaluated and addressed. In this survey, we provide an overview of the current state of research on security of using ChatGPT, with aspects of bias, disinformation, ethics, misuse,attacks and privacy. We review and discuss the literature on these topics and highlight open research questions and future *** this survey, we aim to contribute to the academic discourse on AI security, enriching the understanding of potential risks and mitiga.ions. We anticipate that this survey will be valuable for various stakeholders involved in AI development and usage, including AI researchers, developers, policy makers, and end-users.

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Experimental quantum deletion in an NMR quantum information processor

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Science China(Physics,Mechanics & Astronomy) 2014年第7期57卷 1256-1261页

作者： long Yu FENG GuanRu PEARSON Jasong long GuiLu State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics Tsinghua University Collaborative Innovation Center of Quantum Matter Tsinghua National Laboratory for Information Science and Technology Tsinghua University

We report an NMR experimental realization of a rapid quantum deletion algorithm that deletes marked states in an unsorted *** classical deletion,where search and deletion are equivalent,quantum deletion can be implemented with only a single query,which achieves exponential speed-up compared to the optimal classical *** the experimental realization,the GRAPE algorithm was used to obtain an optimized NMR pulse sequence,and the efficient method of maximum-likelihood has been used to reconstruct the experimental output state.

关键词： quantum deletion algorithm quantum computing nuclear magnetic resonance quantum search algorithm

An Improved Differential Fault Analysis on Block Cipher KLEIN-64

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Computers, Materials & Continua 2020年第11期65卷 1425-1436页

作者： Min long Man Kong Sai long Xiang Zhang Changsha University of Science and Technology Changsha410014China School of Computing National University of SingaporeSingapore

KLEIN-64 is a lightweight block cipher designed for resource-constrained environment,and it has advantages in software performance and hardware *** investiga.ion shows that KLEIN-64 is vulnerable to differential fault attack(DFA).In this paper,an improved DFA is performed to *** is found that the differential propaga.ion path and the distribution of the S-box can be fully utilized to distinguish the correct and wrong keys when a half-byte fault is injected in the 10th *** analyzing the difference matrix before the last round of S-box,the location of fault injection can be limited to a small ***,this improved analysis can greatly improve the attack *** the best case,the scale of brute-force attack is only *** for the worst case,the scale of brute-force attack is far less than 232 with another half byte fault injection,and the probability for this case is 1/***,the measures for KLEIN-64 in resisting the improved DFA are proposed.

关键词： Block cipher KLEIN-64 differential fault analysis half-byte fault injection

REGIONAL TOURISM COOPERATION IN TRIANGLE ZONE OF LIAONING PROVINCE

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Chinese Geographical Science 2005年第4期15卷 361-367页

作者： long Jiang-zhi School of Tourism and Hotel Management Dongbei University of Finance ＆ Economics Dalian 116025 P. R. China

Strengthening the regional tourism cooperation is the requirement of both tourism development and tourist competition drive. On the one hand, resources, products, market and infrastructure in tourism are characteristics of half-public goods, which are the externalities. On the other hand, tourism competition has evolved from individual scenic spot, or finn competition to regional competition, which also requires urgent regional tourism cooperation. In recent years, the regional economic cooperation has been becoming popular in the world. The triangle tourism zone of Liaoning Province, constituted by Shenyang, Dalian and Dandong, is the core region of Liaoning tourism system. This regional tourism cooperation has been raised for a long time, but has not made substantial progress as yet. In recent years, the strategic cooperation among them has been becoming urgent, along with the change of tourism competition models, as well as the desire for building a Northeast Asia tourist economy circle. Based on literature, this paper establishes a conceptual frame of regional tourism cooperation and applies it in the analysis of the strategic tourism cooperation of Liaoning Province＇s golden triangle zone. This paper firstly examines both qualifications and motives concerning with cooperation among the three cities, and believes that the biggest difficulties involve traditional ideas, administrative institutions, communications, economic performances, time constraints, and more overlap among their tourist markets. Then this paper continues to construct a cooperating mechanism, including participant arrangements, construction of operating mechanism and construction of assisting mechanism. At last, this paper proposes approaches to the strategic cooperation such as introducing Xiuyan County, strategic integration and developing differentiated and complemented tourism products.

关键词： regional tourism cooperation triangle tourism zone of Liaoning

A bright integrated photon pair source

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 1-2页

作者： Gui-Lu long Department of Physics Tsinghua University

The generation and detection of single photons and photon pairs are crucial to quantum information processing[1-7].Of the various techniques,integrated photonics plays an important *** has the advantages of mature complementary metal-oxide-semiconductor(CMOS)mass-fabrication,miniaturization,scalability,stability and reconfigurability,thus becoming a natural choice for integrated quantum information ***,due to the lack of second-order nonlinearity,the silicon chip usually adopts the relatively weak third-order nonlinear interaction,namely the spontaneous four-wave mixing,to generate photon *** improve the photon pair generation rate,silicon micro-ring resonators are considered candidates capable of enhancing the intense intracavity field for the pump,signal and idler photons.

关键词： pump photon quantum