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Efficient nonlocal two-step entanglement concentration protocol for three-level atoms in an arbitrary less-entangled W state using cavity input-output process

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Science China(Physics,Mechanics & Astronomy) 2014年第8期57卷 1511-1518页

作者： ZHANG Ru ZHOU SuHua cao cong Department of Communications & Information Engineering Century College Beijing University of Posts and Telecommunications School of Science Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

We present an efficient two-step entanglement concentration protocol(ECP)for three-level atoms trapped in one-sided optical micro-cavities in an arbitrary three-particle less-entangled W state,using the coherent state input-output process in low-Q cavity quantum electrodynamics *** each step of the new proposed protocol,one of the three remote users prepares the auxiliary coherent optical pulses to perform cavity input-output process and then utilizes the standard homodyne measurement to discriminate the final outgoing coherent *** both of the two steps are successful,remote parties can deterministically concentrate the less-entangled W state atoms to a standard maximally entangled W *** with previous ECPs for W state,this protocol has some advantages and can be widely used in current quantum repeater and some quantum information processing tasks.

关键词： entanglement concentration protocol W state cavity input-output process

重庆“四山”生态环境状况时空特征与障碍因子分析

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水土保持研究 2025年第2期32卷 353-365页

作者：谢慧君曹聪范泽英杜清江刘智尹小彤重庆市地质矿产勘查开发局南江水文地质工程地质队重庆401121 重庆市地下水资源利用与环境保护实验室重庆401121 重庆市地质矿产勘查开发局208水文地质工程地质队(重庆市地质灾害防治工程勘查设计院) 重庆400700

[目的]重庆“四山”地区是重庆重点生态功能区,开展重庆“四山”生态环境状况和障碍因子研究,对进一步保护和合理利用四山资源具有重要指导意义。[方法]基于DEM、土地利用类型、植被覆盖率和地下水水位监测站等数据基础,采用AHP-PCA熵... 详细信息

[目的]重庆“四山”地区是重庆重点生态功能区,开展重庆“四山”生态环境状况和障碍因子研究,对进一步保护和合理利用四山资源具有重要指导意义。[方法]基于DEM、土地利用类型、植被覆盖率和地下水水位监测站等数据基础,采用AHP-PCA熵权组合模型、空间自相关分析和障碍度模型等方法,分析了重庆四山地区生态环境质量时空变化特征,探讨了不同聚集模式下的生态环境质量变化趋势,量化了各影响因子对四山生态环境质量影响的障碍度。[结果](1)2014—2021年重庆四山地区生态环境质量状况较好,整体以改善趋势为主(面积占比36.24%);局部出现恶化趋势(面积占比24.20%),主要分布在人类活动频繁的槽谷地带。(2)研究区不同等级生态环境质量发生转移,生态环境质量极差和优的区域具有一定稳定性,分别有59.36%和73.22%的区域未发生变化;生态环境质量差、一般和良的区域流动性相对较大,发生转移的面积占比分别为63.69%,54.09%和43.65%。不同山脉中,明月山生态环境质量稳定性较高,中梁山生态环境质量改善趋势最小,缙云山生态环境质量存在恶化的风险较其他山脉更大。(3)聚类和异常值分析结果显示:四山生态环境质量的高值区域和低值区域具有显著的空间聚集特征(p<0.01),高—低模式下生态环境质量面临进一步恶化的可能,低—高模式下,反映出生态环境可能存在潜在受损状态。(4)重庆四山地区影响生态环境的各因子中地下水水位障碍度最大,其次为植被覆盖率、生物丰度和城镇开发强度;障碍度变化较大的为隧道建设密度、地下水水位和地表水体丰度,其中隧道建设密度障碍度增加,地下水水位和地表水体丰度障碍度降低。[结论]四山地区生态环境状况向好发展,局部生态环境质量较差,隧道建设密度对生态环境的影响增加。

关键词：生态环境质量时空变化人类活动障碍因子 AHP-PCA熵权

Actual wellbore tortuosity evaluation using a new quasi-three-dimensional approach

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Petroleum 2022年第1期8卷 118-127页

作者： Jun Jing Wenyong Ye cong cao Xiaomin Ran School of Mechatronic Engineering Southwest Petroleum UniversityChengduChina CNPC Chuanqing Drilling Engineering Company Limited Xi’anChina National Engineering Laboratory for Low-permeability Oil&Gasfield Exploration and Development Xi’anChina CNPC BOHAI Drilling Engineering Company Limited TianjinChina Sichuan Vocational College of International Technology GuangyuanChina

The irregular wellbore trajectory caused by the wellbore deviation and fluctuation makes a significant effect on the torque and drag in extending and direction drilling,especially for wellbore trajectory with obvious deviation in the drilling *** a consequence,a new quasi-three-dimensional wellbore tortuosity evaluation method is *** new method incorporates the effect of fluctuation frequency and amplitude of oscillating wellbore trajectory;a weight coefficient index that quantifies the effect of tortuosity of one segment trajectory to the entire trajectory;a‘Peak-Valley’principle that can decompose the irregular wellbore trajectory in various scale *** studies show that the deflection angle between the segments of tortuous wellbore increases the torque and drag by strengthening the contact behaviors between the drillstring and ***,the deflection angle is introduced to quantify the effect of deviation in the drilling direction on wellbore *** evaluation results of two field cases demonstrate the new method which is adapted to the wellbore trajectory fluctuating with various characteristics and can reflect the actual state of wellbore tortuosity with severe oscillation more effectively and accurately.

关键词： Wellbore trajectory Deflection angle Peak-valley principle Evaluation method

Synthesis of NaYF_4:Nd@NaLuF_4@SiO_2@PS colloids for fluorescence imaging in the second biological window

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Journal of Rare Earths 2018年第2期36卷 113-118页

作者： Dongpeng Yang cong cao Wei Feng Chunhui Huang Fuyou Li Department of Chemistry State Key Laboratory of Molecular Engineering of PolymersInstitutes of Biomedical Sciences & Collaborative Innovation Center of Chemistry for Energy Materials Fudan University

Nd doped nanoparticles is commonly used as bioimaging agents but presents poor stability. Here, a polymer coating is applied to NaYF4：Nd nanoparticles using a versatile step-by-step coating strategy. The as-synthesized NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids show good stability in various polar solvent and are very stable in water at least for 6 months. These NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids can exhibit strong down converting photoluminescence when excited by 808 nm lasers. Moreover, these NaYF_4：Nd@NaLuF_4@SiO_2@PS colloids accumulate in liver of mice when used as bio-imaging agents. which exhibit strong fluorescence luminescence in NIR Ⅱ window.

关键词： Neodymium Polystyrene Stability Bioimaging Rare earths

Evaluating therapeutic outcome in epileptic patients using the changes of interval and duration

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Neural Regeneration Research 2007年第11期2卷 655-659页

作者： Xinhui cao cong Feng Zhumadian Psychiatric Hospital Zhumadian 463000 He＇nan Province China

BACKGROUND： Seizure frequency is in abnormal distribution, and it is not enough to express the trend of concentration using means, and its median loses a lot of information, thus it lacks of a standard for evaluating the therapeutic effects based on seizure frequency. OBJECTIVE： To establish a method for evaluating the therapeutic effects on anti-epileptic drugs using changes of interval and duration of seizure. DESIGN： A prospective cohort study. SETTING： Zhumadian Psychiatric Hospital. PARTICIPANTS： Outpatients and inpatients suffering from epilepsy attending firstly visited Zhumadian Psychiatric Hospital from June 2001 to June 2002 were enrolled. They were diagnosed as epileptic according to the International Classification of Epileptic Seizure by International League Against Epilepsy （1981） based on the clinical history, physical examination, and investigations. The interval time was no more than 6 months. Informed consent was obtained from all the subjects, and the study was approved by the hospital ethical committee. METHODS： ① For the first visit and each follow-up, the following data were recorded, including general demographic information, seizure type, the date and time of ictus, the duration of ictus, and inducement or situation related, according to which the following indexes could be calculated, including seizure styles, interval, duration, cluster frequency and cluster duration. The information from the first review was noted as annals A. The second interview was taken at the end of the evaluating period; the information from the second review was noted as annals B. The third interview was taken within two weeks after the second one; the information from the third review was noted as annals C. The annals B or the annals C were respectively compared with the annals A in the light of the same types or the same styles of the same patient. Summation of the scores of interval change and duration change of the same type or the same style and 5 of

关键词： epilepsy seizure severity scale seizure frequency seizure severity therapeutic effects

An efficient approach to representing and mining knowledge from Qing court medical records

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Frontiers of Computer Science 2011年第4期5卷 395-404页

作者： Weimin WANG Jingchun ZHANG cong cao Tao HOU Yue LIU Keji CHEN Graduate School Chinese Academy of Sciences Beijing 100190 China Cardiovascular Department of Xiyuan Hospital China Academy of Chinese Medical Sciences Beijing 100091 China School of Computer Science ＆ Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China

Research on Qing Court Medical Records （RQCMR） is a large-volume book which was edited and annotated by the sixth co-author Keji, Chen and his colleagues, and consists of all the medical records of imperial families and aristocrats of the Qing dynasty. To reveal and utilize their high value both in traditional Chinese medicine research and modem clinical practice, we have developed a method of transforming the Qing Court Medical Records （QCMR） into a computer-read- able, structured representation, so that statistical analysis and data mining can be accurately performed. The method consists of a frame ontology based medical language, called MedL, for representing QCMR, a parser for compiling MedL frames into a database, and an explorative pattem mining technique. With this method the entire RQCMR volume is transformed into a database and medical patterns may be mined from the database.

关键词： Traditional Chinese medicine Qing court medical records frame ontology explorative pattern mining

Concentrating partially entangledW-class states on nonlocal atoms using low-Q optical cavity and linear optical elements

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Science China(Physics,Mechanics & Astronomy) 2016年第10期59卷 42-48页

作者： cong cao Xi Chen YuWen Duan Ling Fan Ru Zhang TieJunWang Chuan Wang State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Ethnic Minority Education Beijing University of Posts and Telecommunications School of Science Beijing University of Posts and Telecommunications

Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol(ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low-Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics(QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low-Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.

关键词： entanglement concentration W-class states cavity QED linear optical elements

Multi-particle Entanglement Generation Using Quantum-Dot Spin and Optical Microcavity System

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Chinese Physics Letters 2012年第7期29卷 18-20页

作者： ZHANG Chuan-Lin WANG Chuan cao cong ZHANG Ru School of Science Beijing University of Posts and TelecommunicationsBeijing 100876 State Key Laboratory of Information Photonics and Optical Communications Beijing 100876

We propose an efficient multi-particle entanglement generation protocol using a quantum dot and optical microcavity coupled ***-electron spins may become entangled by the interaction between the electrons and the single *** entanglement success probability relies on the coupling strength and the cavity leakage,which is also discussed.

关键词： particle quantum coupling

Phase-controlled photon blockade in optomechanical systems

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Fundamental Research 2023年第1期3卷 30-36页

作者： Yong-Pan Gao cong cao Peng-Fei Lu Chuan Wang School of Electronic Engineering and the State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China School of Artificial Intelligence Beijing Normal UniversityBeijing 100875China

The manipulation of photons is a key technology for obtaining optical quantum *** this study,we present a phase-modulated optomechanical system comprising two coupled cavity resonators and illustrate the phase-controlled photon blockade in the *** coupling phase of the cavities reveals the interference of photons and introduces an unconventional photon-blockade *** also study the influence of the energy level fineness on the photon blockade and resonant frequency of the mechanical *** simulations demonstrate that photon blockade can occur over a wide range of system *** results have several implications for understanding the role of the state phase in quantum cavity optomechanics and provide a promising method for the realization of optomechanical quantum devices using photon blockade.

关键词： Photon blockade Optomechanics State phase Correlation function Broad frequency range