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Tunable non-Markovian and quantum coherence in the single-qubit dephasing noise channel

Science China(Physics,Mechanics & Astronomy) 2025年第3期Mechanics & Astronomy) .卷 96-105页

作者： Na-Na Zhang Chao-Yi Wu Xu Zhou Qi-Yuan liu Cheng-ge liu Yong-Rui Guo Ren-Pu Li School of Optoelectronic Engineering Chongqing University of Posts and Telecommunications Department of Physics Applied Optics Beijing Area Major Laboratory Beijing Normal University

In this paper, we construct a single-qubit dephasing noise channel based on the nuclear magnetic resonance（NMR） system by employing the bath-engineering technology, and achieve the construction of the tunable non-Markovian environment in the dephasing noise channel. Our findings indicate that for the single-qubit system, the transition of system dynamics from Markovian to non-Markovian can be achieved by adjusting the base frequency of the noise power spectrum. However, the base frequency corresponding to this phase transition point is not fixed, and there is a certain relationship between it and the total evolution time of the single-qubit system. Through our research, we discovered a fundamental relationship: if the single-qubit system dynamics undergoe a transition from Markovian to non-Markovian at ω0within 0-2t ms, shortening the evolution time to 0-t ms results in an increase of the phase transition point to 2ω0. This insight offers crucial guidance for artificially crafting non-Markovian environments across arbitrary time scales in single-qubit systems, and it is not limited by the type of noise. Apart from system dynamics, quantum coherence is also a focal point of our research. We find that when the system dynamics exhibit non-Markovian behavior, the quantum coherence of the single-qubit system experiences revivals. Notably, the timing of these coherence revivals aligns with the instants of the non-Markovianity enhancement. Therefore, our research also serves as a pivotal foundation for the artificial manipulation and realization of quantum coherence revivals within diverse single-qubit systems.

关键词： dephasing noise channel non-Markovian quantum coherence

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基于遥感的1984-2019年查干湖及周边湖泊透明度变化

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湖泊科学 2025年第1期37卷 328-338页

作者：赵方睿王强穆春生刘阁温志丹陶慧宋开山东北师范大学生命科学学院长春130024 中国科学院东北地理与农业生态研究所长春130102

湖泊透明度是衡量水质变化和湖泊水生生态系统健康的重要指标。湖泊透明度一般通过塞氏盘现场观测获得,其变化主要由水体中非藻类颗粒物、藻类和黄色物质(CDOM)浓度共同决定,因此可以通过光学遥感进行反演。本研究基于20042009年8次查... 详细信息

湖泊透明度是衡量水质变化和湖泊水生生态系统健康的重要指标。湖泊透明度一般通过塞氏盘现场观测获得,其变化主要由水体中非藻类颗粒物、藻类和黄色物质(CDOM)浓度共同决定,因此可以通过光学遥感进行反演。本研究基于20042009年8次查干湖实地采样获得的132条透明度数据,通过分析同步Landsat天顶反射率产品数据(TOA)不同波段组合与透明度之间的相关性,发现以红波段和蓝波段比值和红绿蓝波段均值AV(B3,B1)组合建立的透明度反演模型精度最高,误差最小,进而基于此模型反演了19842019年查干湖以及周边湖泊透明度。结果表明:查干湖透明度范围在1.0~63.0 cm之间,年均值为17.6 cm。查干湖透明度年均值变化分为两个阶段:19842001年间透明度波动范围较大,没有明显趋势;20022019年期间呈上升趋势(2.3 cm/10 a)。查干湖透明度与风速、降水量、湖泊面积和归一化植被指数具有一定的相关性。通过长时间尺度上遥感监测查干湖水体透明度的时空格局变化,分析其变化特征与规律,可为查干湖流域生态治理提供科学依据。

关键词：查干湖透明度 Landsat 遥感

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数字经济发展测度及空间分异研究——以京津冀和长三角为例

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科技与经济 2025年第1期38卷 71-75页

作者：刘格王春艳燕山大学理学院河北秦皇岛066004

研究中国区域数字经济发展水平及其空间分异特征,构建数字经济发展水平指标体系,利用熵权法测度2012-2022年京津冀和长三角地区各省市数字经济指数,从而量化数字经济发展水平。通过核密度估计和Dagum基尼系数分解,对两个区域发展水平差... 详细信息

研究中国区域数字经济发展水平及其空间分异特征,构建数字经济发展水平指标体系,利用熵权法测度2012-2022年京津冀和长三角地区各省市数字经济指数,从而量化数字经济发展水平。通过核密度估计和Dagum基尼系数分解,对两个区域发展水平差异、发展不均衡程度以及整体趋势进行实证分析。结果表明,京津冀地区数字经济发展水平低于长三角地区,其中北京和江苏增幅较大,天津和安徽增幅较小;两个区域内部数字经济发展水平均呈现多极化特征;从地区内差异看,京津冀地区内部差异大于长三角地区内部差异,两个地区之间的差异总体上呈缩小趋势。数字经济的整体发展差异主要由区域内的不平衡造成。

关键词：区域发展数字经济熵权法核密度估计 Dagum基尼系数分解区域差异

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A 220 GHz Orthogonal Modulator Based on Subharmonic Mixers Using Anti-Paralleled Schottky Diodes

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Chinese Journal of Electronics 2022年第3期31卷 562-568页

作者： HE Yue liu ge liu Juan LIN Changxing SU Wei Microsystem and Terahertz Research Center China Academy of Engineering Physics Institute of Electronic Engineering China Academy of Engineering Physics

In this paper, A 220 GHz orthogonal modulator based on two symmetrical subharmonic mixers is designed, analyzed and measured, where the mixers are implemented basde on antiparallel Schottky *** orthogonal modulator consists of a 90° phase shifted220 GHz 3 d B coupler, two sub-harmonically pumped mixers and an in-phase 110 GHz 3 d B power divider. The IF output signals are in-phase(I) branch and quadrature(Q) branch operating from DC±3.5 GHz. In the back to back experimentaltests, it is shown that the conversion loss of the two 220 GHz I/Q mixers is less than 30 d B when the IF operating frequency is DC-3.5 GHz, IF input power is-10 d Bm and the LO power is around 6 m W. Based on floating-point simulation, the amplitude and phase imbalance of the I/Q mixer are less than 0.2 d B and 2 degree respectively. When the 220 GHz modulator and demodulator are set in a back to back configuration, a signal-to-noise ratio of 21 d B can be obtained using the 16 QAM modulation type.

关键词： subharmonic mixers amplitude imbalance I-Q mixer floating-point simulation power dividers millimetre wave mixers millimetre wave diodes waveguide couplers quadrature amplitude modulation Schottky diode mixers radio-over-fibre phase imbalance orthogonal modulator power divider 16 QAM modulation subharmonically pumped mixers quadrature branch in-phase branch antiparalleled Schottky diodes waveguide coupler

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Marine bacterial surfactin CS30-2 induced necrosis-like cell death in Huh7.5 liver cancer cells

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Journal of Oceanology and Limnology 2020年第3期38卷 826-833页

作者： ZHOU Shengnan liu ge WU Shimei College of Life Sciences Qingdao UniversityQingdao 266071China Key Laboratory of Experimental Marine Biology Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

Marine bacterial strain Bacillus ***30 exhibited high anticancer activity against Huh7.5 human liver *** purified the corresponding anticancer agent by sequential acidic precipitation,methanol extraction,Sephadex LH-20 chromatography,and reversed phase high-performance liquid chromatography(RP-HPLC),then analyzed it in mass *** on the results of purification and mass spectrometry,we deduced that the anticancer agent was the same component as our previously purified antifungal agent surfactin ***,to the best of our knowledge,this is the first report on the surfactin possessing both antifungal and anticancer *** CS30-2 was demonstrated to exhibit high anticancer activity in a dose-dependent manner against Huh7.5 liver cancer *** investigation showed that surfactin CS30-2 induced the increased generation of reactive oxygen species(ROS)and severe disruption of cell membrane,thus leading to cell ***,unlike previously reported surfactins,surfactin CS30-2 caused cancer cell death via necrosis instead of apoptosis.

关键词： Bacillus surfactin anticancer activity reactive oxygen species(ROS)

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Synthesis of LiFePO_4 /C as cathode material by a novel optimized hydrothermal method

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Rare Metals 2011年第5期30卷 433-438页

作者： GAO ge liu Aifang HU Zhonghua XU Yuanyuan liu Yafei Department of Chemistry Tongii University Shanghai 200092 China

Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step （350℃ and 700℃） calcinated under high-purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and electrochemical tests, which include charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li：Fe：P molar ratio at 3：1：1 and the reaction temperature at 180℃ for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g-1 at 0.1C, exhibits a stable and narrow-gapped charge-discharge platform and small capacity losses after cycles.

关键词： lithium ion batteries cathode materials phosphates olivine carbon deposition hydrothermal synthesis

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Construction of optimal supersaturated designs by the packing method

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Science China Mathematics 2004年第1期47卷 128-143页

作者： FANG Kaitai ge gennian liu Minqian Department of Mathematics Hong Kong Baptist University Hong Kong China Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Statistics Nankai University Tianjin 300071 China

A supersaturated design is essentially a factorial design with the equal occurrence of levels property and no fully aliased factors in which the number of main effects is greater than the number of runs. It has received much recent interest because of its potential in factor screening experiments. A packing design is an important object in combinatorial design theory. In this paper, a strong link between the two apparently unrelated kinds of designs is shown. Several criteria for comparing supersaturated designs are proposed, their properties and connections with other existing criteria are discussed. A combinatorial approach, called the packing method, for constructing optimal supersaturated designs is presented, and properties of the resulting designs are also investigated. Comparisons between the new designs and other existing designs are given, which show that our construction method and the newly constructed designs have good properties.

关键词： Kirkman triple systems, orthogonality, packing design, resolvability, supersaturated design.

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East Asian-North Indian Ocean thermal contrast and variation in the East Asian summer monsoon for the past 2650 years

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Science China Earth Sciences 2011年第5期54卷 773-779页

作者： liu ge ZHAO Ping ZHOU XiuJi Chinese Academy of Meteorological Sciences Beijing 100081 China National Meteorological Information Centre Beijing 100081 China

Using observational data, the East Asian-North Indian Ocean index （]EANI）, which reflects a tropospheric thermal contrast, is found to correlate well with the East Asian summer monsoon （EASM） and associated rainfall over eastern China. Corresponding to a higher （lower） IEANI, the EASM at mid-latitudes is stronger （weaker）, and there is more （less） rainfall in North China and less （more） rainfall near the Yangtze River valley. To investigate long-term variation in the EASM, we reconstructed the BC 665AD 1985 IEANI based on reconstructed temperatures in Beijing and Tasmania, Australia. Over the past 2000 years, the reconstructed/EANI generally represents centennial-scale variations in the EASM and rainfall over eastem China. The correlation pattern between the reconstructed IEANI and rainfall over eastern China is similar to modem observations, implying that the correlation feature at centennial scales also occurred over the past 2000 years. With respect to longer-scale （several hundreds to one thousand years） IEANI variations and their correlations with rainfall, further verifications should be performed using various paleoclimatic proxy data.

关键词： East Asian summer monsoon thermal contrast reconstruction rainfall

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Deformation behavior and processing maps during isothermal compression of TC21 alloy

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Rare Metals 2017年第2期36卷 86-94页

作者： Jun Gao Miao-Quan Li ge-Jun liu Shao-Fei liu School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an 710072China

In this study,isothermal compression tests were conducted at a Gleeble-1500 simulator at deformation temperatures ranging from 1073 to 1283 K,strain rates ranging from 0.01 to 5.00 s^（-1）,and height reductions ranging from 20%to 60%.The flow stress and apparent activation energy for deformation and constitutive equation were used to characterize the deformation behavior of TC21 alloy during the isothermal *** processing maps combined microstructure observations were established based on dynamic material model（DMM） over a range of strain rates and *** results show that an initial yield drop is observed above 1203 K or at higher strain rates ranging from 1.00 to 5.00 s^-1,and oscillatory flow curves are presented particularly at a strain rate of 5.00 s^-*** has some influence on the apparent activation energy for deformation during the isothermal compression of TC21 *** Q-values and microstructure observation confirm that dynamic recrystallization（DRX） occurs in the β single-phase *** constitutive equation during the isothermal compression of TC21 alloy is developed using the Zener-Hollomon parameter in the exponent-type *** maximum and minimum relative errors between the calculated and the experimental flow stress are 14.1%and 0.3%,*** peak efficiency of power dissipation at a strain of 0.7 is about 0.51 occurring at a deformation temperature of 1073 K and strain rate of 0.01 s^-1,corresponding to an optimal deformation condition of TC21 alloy.

关键词： TC21 alloy Flow stress Apparent activation energy for deformation Constitutive equation Processing Maps

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POLY(MALEIC ANHYDRIDE-CO-ACRYLIC ACID)/POLY(ETHYLENE GLYCOL)HYDROgeLS WITH pH- AND IONIC-STRENGTH-RESPONSES

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Chinese Journal of Polymer Science 2010年第6期28卷 951-959页

作者： Meng Yang Bo-tian liu ge Gao Xiao-li liu Feng-qi liu College of Chemistry and Macdiarmid Laboratory Jilin University Changchun 130012 China

Poly（maleic anhydride-coacrylic acid）,P（MA-AA）,was synthesized by the free-radical copolymerization of maleic anhydride with acrylic acid,and fast responsive pH-sensitive poly（maleic anhydride-co-acrylic acid）/polyethylene glycol,P（MA-AA）/PEG,hydrogels were prepared using PEG as macromolecular cross-linking ***-IR and ~1H-NMR spectrometry were applied to characterize the structure of P（MA-AA）.The influences of pH and ionic strength on the swelling behavior of P（MA-AA）/PEG hydrogels and the swelling-deswelling changes along with the repeated changes between acid and alkali conditions were *** results showed that there was a hundredfold difference in the swelling ratios between the conditions of acid and alkali,and the swelling capability could not be weakened after multiple swelling-deswelling *** results of swelling kinetics demonstrated that the response rate of P（MA-AA）/PEG hydrogels was very fast,because the swelling transition points always occurred at 10 *** pH-responsive hydrogels reported here might be a smart material for potentially applications in many areas,including biosensors,drug-delivery devices and tissue engineering.

关键词： pH-response P(MA-AA) Macromolecular cross-linking agent External cross-linking

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