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Preparation and thermoelectric transport properties of Ba-, La- and Ag- doped Ca3Co4O9 oxide materials

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Journal of Rare Earths 2013年第8期31卷 778-783页

作者： zhang feipeng LU Qingmei LITingxian zhang Xin zhang Jiuxing SONG Xiaoyan Department of Applied Sciences Henan University of Urban Construction Pingdingshan 467036 China Key Laboratory of Advanced Functional Materi- als Chinese Ministry of Education College of Materials Science and Engineering Beijing University of Technology Beijing 100124 China College of Phys- ics and Electrical Engineering Anyang Normal University Anyang 455002 China

The Ba-, La- and Ag-doped polycrystalline Ca2.9M0.1Co4O9 （M=Ca, Ba, La, Ag） thermoelectric bulk samples were pre- pared via citrate acid sol-gel synthesis method followed by spark plasma sintering technique. The bulk samples were characterized and analyzed with regard to their phase compositions, grain orientations as well as microstructures. The high temperature thermoelec- tric transport properties of the bulk samples were studied in detail. All bulk samples were found to be single-phased with modified body texture. The electrical resistivity was modulated as a result of carrier concentration modification, however the carrier transport process was not influenced; the Seebeck coefficient was deteriorated simultaneously. The total thermal conductivity was remarkably reduced, on account of the decreasing of phonon thermal conductivity. The thermoelectric properties of the Ba-, La-, and Ag-doped bulk samples were optimized, and the Ba-doped Ca2.9Ba0.1Co4O9 system was found to have the highest dimensionless figure of merit ZT0.20 at 973 K, which was remarkably higher than that of the un-doped sample.

关键词： Ca3Co4O9 oxide Ca-site doping thermoelectric transport properties rare earths

Dynamic relationship between volume and volatility in the Chinese stock market:evidence from the MS-VAR model

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Data Science and Management 2024年第1期7卷 17-24页

作者： feipeng zhang Yilin zhang Yixiong Xu Yan Chen School of Economics and Finance Xi’an Jiaotong UniversityXi’an710049China Business School Hunan UniversityChangsha410082China

Since market uncertainty,or volatility,serves as a crucial gauge for assessing the traits of market fluctuations,the link between stock market volume and price continues to be a focal point of interest in *** study examines the dynamic,nonlinear correlations between Chinese stock volatility,trading volume,and return using a hybrid approach that combines the Markov-switching regime with the vector autoregressive model(MS-VAR).The empirical findings are as follows:(1)The Chinese stock market can be divided into three regional systems:steady downward,steady upward,and high *** three states have similar frequencies of occurrence,and their corresponding stable probabilities are not high,indicating that the Chinese stock market is unstable.(2)Asymmetric dynamic relationships exist between market volatility,investment return,and trading *** different regimes,while the effect of trading volume on volatility and return appears to be insignificant,the impacts of volatility and return on trading volume are considerably strong.(3)A regime-dependent,contemporaneous correlation between volatility and return is observed,which also reflects the behavior of the Chinese stock market“chasing up and down”.However,a positive contemporaneous correlation always exists between volatility and trading volumes in different regimes,indicating that uncertainty in the Chinese stock market is closely related to information inflow.

关键词： Volatility Trading volume MS-VAR model Chinese stock market

Seasonal vertical crustal mo-tions in China detected by GPS

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维普期刊数据库

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Chinese Science Bulletin 2002年第21期47卷 1772-1780,1849页

作者： zhang feipeng DONG Danan CHENG Zongyi CHENG Mingkang HUANG Cheng Shanghai Astronomical Observatory National Astronomical ObservatoryUnited Center for Astro-geodynamics ResearchChinese Academy of SciencesShanghai 200030China Jet Propulsion Laboratory California Institute of Technology4800 Oak Grove Dr.Pasadena78759 CaliforniaUSA Center for Space Research University of Texas at Austin91109 AustinUSA

By analyzing daily continuous data of Chinese Global Positioning System (GPS) fiducial network with 25 sites from 1999 to 2001, seasonal altitude variations with amplitude of 3-10 mm are detected. Most part of the variations can be explained by the seasonal vertical crustal movements caused by atmospheric pressure variation and mass loading redistribution of non-tidal ocean loading, snow, and soil moisture. Nevertheless, there exists a systematic discrepancy between GPS deduced result and the counterpart predicted by combining various geophysical sources. Much longer time series of GPS site coordinates and further studies are still needed to give out a reasonable interpretation for this discrepancy.

关键词： crustal movement seasonal altitude variation GPS mass loading redistribution.

Late Mesozoic tectonostratigraphic division and correlation of the Bohai Bay basin: Implications for the Yanshanian Orogeny

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Science China Earth Sciences 2019年第11期62卷 1783-1804页

作者： Jichang ZHU Youliang FENG Qing-Ren MENG Fengcheng WU Hao LI Haitao LIU feipeng zhang Tianyu WANG Guoli WU Caineng ZOU Rixiang ZHU Institute of Geology and Geophysics CASBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Innovation Academy for Earth Science CASBeijing 100029China PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Institute of Sinopec Exploration and Development Research Beijing 100083China School of Geosciences China University of PetroleumQingdao 266580China

We present the results of Mesozoic sequences of the Bohai Bay basin in North China, based mainly on geochronology and interpretations of seismic profiles and logging data. Five tectono-stratigraphic sequences are defined: Lower-Middle Triassic, Lower-Middle Jurassic, Upper Jurassic, Lower Cretaceous and Upper Cretaceous. Based on an analysis of detrital zircons, the clastic rocks recorded two intervals of Jurassic magmatic activity, during 180–175 and 160–152 Ma, which can be correlated to the Nandaling and Tiaojishan Formations in the Yanshan area, respectively. However, since Jurassic volcanic rocks have not yet been found in the Bohai Bay basin, we speculate that these two stages of activity were mainly concentrated around the periphery of the North China Craton(NCC) rather than within. Based on an analysis of zircons from volcanic rocks and pyroclastics, the early Cretaceous magmatism in the Bohai Bay basin can be divided into two stages, 125–120 and 110–100 Ma,which can be correlated to magmatism in the eastern part of the NCC. The zircon ages indicate an absence of volcanic activity during the late Tuchengzi and zhangjiakou periods which may correlate to the uplift of the Bohai Bay basin in the late Late Jurassic. Comparison of the development of Mesozoic basins and sedimentary strata in the central-eastern part of Yanshan tectonic belt and the the Bohai Bay basin indicates that the two areas are generally comparable, but with substantial *** central-eastern part of the Yanshan structural belt lacks Early-Middle Triassic strata, and the Bohai Bay basin lacks late Jurassic-early Cretaceous strata. Based on research results from late Mesozoic sedimentary structures in the central and eastern parts of the Yanshan tectonic belt, we infer that episode A of the Yanshanian Orogeny was weak in the Bohai Bay basin and its periphery, while episode B of the Yanshanian Orogeny had a strong influence on the Bohai Bay basin and its periphery. The available data

关键词： Yanshanian Orogeny Late Mesozoic Central-eastern part of Yanshan tectonic belt The Bohai Bay basin Tectonostratigraphic division

Effects of praseodymium doping on thermoelectric transport properties of CaMnO_3 compound system

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Journal of Rare Earths 2013年第9期31卷 885-890页

作者：张飞鹏牛保成张坤书张忻路清梅张久兴 Institute of Physics Henan University of Urban Construction Key Laboratory of Advanced Functional Materials Chinese Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Technology

The rare earth Pr doped Ca1-xPrxMnO3 （x=0, 0.06, 0.08, 0.1, 0.12, and 0.14） compound bulk samples were prepared to study the effect of Pr doping on thermoelectric transport properties of CaMnO3 compound system. The doped samples exhibited sin-gle phase composition within the experimental doping range, with condensed bulk microstructure and small porosities. The electrical resistivity was remarkably reduced for doped samples, on account of the enhanced carrier concentration;the absolute value of See-beck coefficient was deteriorated mainly due to enhanced electron carrier concentration. The electrical performances of the doped samples reflected by resistivity and Seebeck coefficient fluctuations were optimistically tuned, with an optimized power factor value of 0.342 mW/（m·K2） at 873 K for x=0.08 sample, which was very much higher comparing with that of the un-doped sample. The lattice thermal conduction was really confined, leading to distinctly repressed total thermal conductivity. The thermoelectric per-formance was noticeably improved by Pr doping and the dimensionless figure of merit ZT for the Ca0.92Pr0.08MnO3 compound was favorably optimized with the maximum value 0.16 at 873 K.

关键词： CaMnO3 compound Pr doping thermoelectric properties rare earths

柠檬酸用量对制备纳米晶CaMnO_3粉末的影响

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强激光与粒子束 2009年第8期21卷 1235-1238页

作者：张飞鹏张久兴路清梅张冰心北京工业大学材料学院新型功能材料教育部重点实验室北京100124

柠檬酸的用量将影响CaMnO3粉末性能。以金属硝酸盐为原料，去离子水和乙二醇为溶剂，在不同柠檬酸络合剂用量的情况下，采用溶胶凝胶法制备了CaMnO3溶胶。通过煅烧干凝胶前驱物制得了钙钛矿型CaMnO3多晶粉末。利用X射线衍射仪、扫描电... 详细信息

柠檬酸的用量将影响CaMnO3粉末性能。以金属硝酸盐为原料，去离子水和乙二醇为溶剂，在不同柠檬酸络合剂用量的情况下，采用溶胶凝胶法制备了CaMnO3溶胶。通过煅烧干凝胶前驱物制得了钙钛矿型CaMnO3多晶粉末。利用X射线衍射仪、扫描电子显微镜、激光粒度分析仪等手段分析了所得粉末。结果表明：所得钙钛矿型CaMnO3晶粒度在20-50nm之间，粉末为300500nm多边形颗粒，粒度随柠檬酸用量增加而增大，晶粒尺寸也逐渐增大，增幅均较小。

关键词： CaMnO3粉末溶胶凝胶柠檬酸表征

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基于参数编程的弧面五角星加工探索与实践

现代制造工程 2017年第4期 73-75,127页

作者：张飞鹏陕西工业职业技术学院咸阳712000

提出一种以C型补偿原理、参数编程及高级缩放功能综合应用实现空间三维曲面加工的手工编程方法,并以弧面五角星为载体,在分析其结构特点及加工难点的基础上,依据该方法制定工艺及加工流程。针对不同类型刀具的加工原理,分析确定关键参数... 详细信息

提出一种以C型补偿原理、参数编程及高级缩放功能综合应用实现空间三维曲面加工的手工编程方法,并以弧面五角星为载体,在分析其结构特点及加工难点的基础上,依据该方法制定工艺及加工流程。针对不同类型刀具的加工原理,分析确定关键参数,编写加工程序,并在机床上进行验证,最终实现了加工目标。该方法成功解决了刀具干涉导致的星型不能收尖问题。

关键词：手工编程空间曲面缩放功能 C型补偿原理

(Ca_(0.96)D_(0.04))MnO_3(D=Ca,Sr,Rb,Sm)氧化物的制备和热电性能

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稀有金属材料与工程 2019年第2期48卷 644-649页

作者：张静文张飞鹏杨新宇王盼杨之张久兴合肥工业大学先进功能材料与器件安徽省重点实验室安徽合肥230009 河南城建学院建筑光伏一体化河南省工程实验室河南平顶山467036 北京工业大学新型功能材料教育部重点实验室北京100124

利用溶胶凝胶法制备出(Ca_(0.96)D_(0.04))MnO_3(D=Ca,Sr,Rb,Sm)氧化物粉末后,先分别采用氩气气氛的放电等离子烧结和空气气氛的常压烧结制备出CaMnO_3(CMO)块体,并对其进行相组成分析,选择出更为优异的CaMnO3块体制备方法。再进一步制... 详细信息

利用溶胶凝胶法制备出(Ca_(0.96)D_(0.04))MnO_3(D=Ca,Sr,Rb,Sm)氧化物粉末后,先分别采用氩气气氛的放电等离子烧结和空气气氛的常压烧结制备出CaMnO_3(CMO)块体,并对其进行相组成分析,选择出更为优异的CaMnO3块体制备方法。再进一步制备出(Ca_(0.96)D_(0.04))MnO_3(D=Sr, Rb, Sm)氧化物块体,最后对(Ca_(0.96)D_(0.04))MnO_3(D=Ca, Sr, Rb, Sm)块体的物相组成、显微组织和热电性能进行测试分析。实验结果表明:氩气气氛放电等离子烧结制备的CaMnO_3块体发生物相分解,原因是放电等离子烧结的烧结环境贫氧;空气气氛的常压烧结可以得到物相较纯净的(Ca_(0.96)D_(0.04))MnO_3(D=Ca, Sr,Rb, Sm)块体;在整个测试温度范围内,(Ca_(0.96)D_(0.04))MnO_3(D=Sr, Rb, Sm)的ZT值在873 K时达到最大,分别为0.11、0.08和0.07,相比于未掺杂试样提高了1.3～2.2倍。

关键词： CaMnO3 放电等离子烧结掺杂热电性能

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面向大规模复杂网络测量和性能瓶颈分析方法

计算机科学与探索 2017年第2期11卷 262-270页

作者：张飞朋陈琳张京京国防科学技术大学计算机学院长沙410073

针对当前数据中心网络规模巨大,流量行为复杂等特点,研究大规模数据中心网络测量方法,定位当前网络性能瓶颈变得日益重要。分析了当前网络测量研究现状,提出了一种基于分布式自动化测量的性能瓶颈分析方法(automatic measurement-distri... 详细信息

针对当前数据中心网络规模巨大,流量行为复杂等特点,研究大规模数据中心网络测量方法,定位当前网络性能瓶颈变得日益重要。分析了当前网络测量研究现状,提出了一种基于分布式自动化测量的性能瓶颈分析方法(automatic measurement-distributed automatic measurement and performance bottleneck analysis method,AM-DMPA)。该方法能自动生成测量任务集合,下发测量任务,并能根据测量结果不断收敛待测网络规模,快速定位网络中的性能瓶颈链路。在典型的大规模数据中心天河2中,选取6种不同规模的网络环境,使用AM-DMPA方法和传统的网络测量方法进行对比,AM-DMPA方法能够更快速地发现和定位网络中性能瓶颈链路。

关键词：数据中心分布式自动化测量性能瓶颈链路