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Relativistic motion on Gaussian quantum steering for two-mode localized Gaussian states

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Chinese Physics B 2022年第5期31卷 189-196页

作者： Xiao-Long Gong Shuo Cao Yue Fang Tong-Hua Liu School of Physics and Optoelectronic Yangtze UniversityJingzhou 434023China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal University at ZhuhaiZhuhai 519087China

Realistic quantum systems always exhibit gravitational and relativistic *** this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic *** find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of ***,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite *** finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum ***,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.

关键词： relativistic quantum information quantum nonlocality Unruh effect

Comprehensive analysis of the chemical constituents in sulfur-fumigated Lonicerae Japonicae Flos using UHPLC-LTQ-Orbitrap mass spectrometry

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Chinese Journal of Natural Medicines 2020年第2期18卷 148-160页

作者： LIU Zi-Han WANG Yu-Qi MEI Xiao-Dan WANG Fei YANG Xian-Zhao LI Xiao-Dong JIANG Feng ZHANG Jia-Yu School of Chinese Pharmacy Beijing University of Chinese MedicineBeijing 102488China BUCM Institute of Liver Diseases Dongzhimen Hospital affiliated to Beijing University of Chinese MedicineBeijing 100700China Department of Hepatology Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430061China School of Pharmacy Binzhou Medical UniversityYantai 264003China

Lonicerae Japonicae Flos(LJF),a kind of traditional Chinese medicines(TCMs),has functions of detoxifying and evacuating *** the study,a method based on ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry(UHPLC-LTQ-Orbitrap MS)was developed for the chemical constituent analysis of organic acids,flavonoids,iridoids and new-generated compounds in sulfur-fumigated LJF(SF-LJF).Based on the accurate mass measurement(<±5 ppm),chromatographic behavior and diagnostic product ions(DPIs),113 constituents were unambiguously or tentatively characterized from SFLJF extract,including 46 chlorogenic acids,19 flavonoids,29 iridoid glycosides and 19 newly-generated compounds(including 17 sulfur-containing derivatives).In addition,5-CQA(5-caffeoylquinic acid,chlorogenic acid)was chosen to be sulfur-fumigated for the result *** was found that the most significant change of LJF after sulfur fumigation was the occurrence of sulfate or sulfite esterification reactions,which resulted in the emergence of many new sulfur-containing *** results demonstrated that the established method was a useful and efficient analytical tool to comprehensively characterize the material basis of SF-LJF,and also an excellent guidance of quality control about LJF.

关键词： Sulfur fumigation Lonicerae Japonicae Flos Chemical components analysis UHPLC-LTQ-Orbitrap MS

Detection of the urban heat island in beijing using HJ-1B satellite imagery

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Science China Earth Sciences 2010年第S1期53卷 67-73页

作者： YANG Jun1,GONG Peng2,ZHOU JinXing3,HUANG HuaBing2 & WANG Lei2 1 Key Laboratory of Silviculture and Conservation,Ministry of Education,beijing Forestry university,beijing 100083,China 2 State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute of Remote Sensing Applications,Chinese Academy of Sciences and beijing normal university,beijing 100101,China 3 Institute of Desertification Studies,Chinese Academy of Forestry,beijing 100091 China 1. Key Laboratory of Silviculture and Conservation Ministry of Education Beijing Forestry University Beijing 100083 China2. State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China3. Institute of Desertification Studies Chinese Academy of Forestry Beijing 100091 China

Satellite images are used extensively in studying the urban heat island(UHI) *** evaluated the suitability of thermal infrared(TIR) data from the HJ-1B satellite for detecting UHI using a case study in *** modified algorithms for retrieving the land surface temperature(LST) from HJ-1B data were *** results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST *** spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS *** the two algorithms,the mono-window algorithm performed better but further tests are *** more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in China and neighboring countries.

关键词： surface temperature NDVI mono-window algorithm single-channel algorithm

A generalized π2-diffeomorphism finiteness theorem

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Frontiers of Mathematics in China 2020年第2期15卷 399-418页

作者： Xiaochun RONG Xuchao YAO Department of Mathematics Rutgers UniversityNew BrunswickNJ 08903 USA School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

Theπ2-diffeomorphism finiteness result of *** and ***(independently)asserts that the diffeomorphic types of compact n-manifolds M with vanishing first and second homotopy groups can be bounded above in terms of n,and upper bounds on the absolute value of sectional curvature and diameter of *** this paper,we will generalize thisπ2-diffeomorphism finiteness by removing the condition thatπ1(M)-0 and asserting the diffeomorphism finiteness on the Riemannian universal cover of M.

关键词： Collapsing with bounded sectional curvature diffeomorphism finiteness vanishing second homotopy group

A comparison of the transport properties of bilayer graphene,monolayer graphene,and two-dimensional electron gas

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Chinese Physics B 2013年第7期22卷 435-439页

作者：孙立风董利民吴志芳房超 Institute of Nuclear and New Energy Technology Tsinghua University beijing Key Laboratory of Fine Ceramics Institute of Nuclear and New Energy TechnologyTsinghua University

We studied and compared the transport properties of charge carriers in bilayer graphene, monolayer graphene, and the conventional semiconductors （the two-dimensional electron gas （2DEG））. It is elucidated that the normal incidence transmission in the bilayer graphene is identical to that in the 2DEG but totally different from that in the monolayer graphene. However, resonant peaks appear in the non-normal incidence transmission profile for a high barrier in the bilayer graphene, which do not occur in the 2DEG. Furthermore, there are tunneling and forbidden regions in the transmission spectrum for each material, and the division of the two regions has been given in the work. The tunneling region covers a wide range of the incident energy for the two graphene systems, but only exists under specific conditions for the 2DEG. The counterparts of the transmission in the conductance profile are also given for the three materials, which may be used as high-performance devices based on the bilayer graphene.

关键词： bilayer graphene monolayer graphene two-dimensional electron gas (2DEG) transport properties

A novel coated-particle design and fluidized-bed chemical vapor deposition preparation method for fuel-element identification in a nuclear reactor

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Particuology 2017年第2期15卷 35-41页

作者： Rongzheng Liu Malin Liu Youlin Shao Xiaotong Chen Jingtao Ma Bing Liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Tsinghua University Beijing100084 China

Particle coating is an important method that can be used to expand particle-technology applications. Coated-particle design and preparation for nuclear fuel-element trajectory tracing were focused on in this paper. Particles that contain elemental cobalt were selected because of the characteristic gamma ray spectra of 60Co. A novel particle-structure design was proposed by coating particles that contain elemental cobalt with a high-density silicon-carbide （SiC） layer. During the coating process with the high-density SiC layer, cobalt metal was formed and diffused towards the coating, so an inner SiC–CoxSi layer was designed and obtained by fluidized-bed chemical vapor deposition coupled with in-situ chemical reaction. The coating layers were studied by X-ray diffractometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy techniques. The chemical composition was also determined by inductively coupled plasma optical emission spectrometry. The novel particle design can reduce the formation of metallic cobalt and prevent cobalt diffusion in the coating process, which can maintain safety in a nuclear reactor for an extended period. The experimental results also validated that coated particles maintain their structural integrity at extremely high temperatures （～1950 °C）, which meets the requirements of next-generation nuclear reactors.

关键词： Particle coating Particle design Cobalt Pluidized-bed chemical vapor deposition Nuclear fuel

Does the Entrepreneurship of the Parents Affect the Opportunities of their Offspring＇s Entrepreneurship？ Empirical Analysis Based on the CGSS 2010-2013 Data

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2018年第2期13卷 196-222页

作者： Yongmei Hu Yun Xing Faculty of Education Beijing Normal University Beijing 100875 China College of Education Northwest Normal University Lanzhou 730070 China

The whole society is paying close attention to ＂entrepreneurship,＂ which urges researchers to find an explanatory perspective relatively independent and with causality on the intergenerational transfer of entrepreneurship. Based on the data of the Chinese General Social Survey （short for CGSS） during the years 2010-2013, this paper analyzes how parents＇ entrepreneurship affects the probability of their offspring＇s entrepreneurship, and the results show that compared with the offspring of parents who did not start their own business, those whose parents did are more likely to choose to start their own business. In view of historical facts such as the ＂lay-off wave＂ during China＇s transformation into a market economy, we use ＂the annual number of unemployed back to work,＂ a provincial-level indicator, in the 1990s as an instrumental variable to correct possible endogenous problems. We find that parents＇ entrepreneurship has significant positive effects on the probability of their offspring＇s entrepreneurship, which may result from the informal transfer of human capital and wealth from parents to their offspring.

关键词： entrepreneurial opportunities instrumental variable regression lay-offs intergenerational transfer

Design of electron wave filters in monolayer graphene with velocity modulations

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Chinese Physics B 2013年第4期22卷 410-414页

作者：孙立风董利民房超 Institute of Nuclear and New Energy Technology Tsinghua University beijing Key Laboratory of Fine Ceramics Institute of Nuclear and New Energy Technology

We compare the transport properties of electrons in monolayer graphene by modulating the Fermi velocity inside the barrier. A critical transmission angle is found only when the Fermi velocity in the barriers is larger than the one outside the barriers. It is shown that the transmission exhibits periodicity with the incident angle below the critical transmission angle, and attenuates exponentially in the opposite situation. For both situations, peak splitting occurs in the transmission as the number of the velocity barriers increases, and the characteristics of the transmission suggest an interesting application of an excellent band-pass filter. The dependence of the conductance on the Fermi energy through an identical velocity- modulation structure differs wildly with different Fermi velocities of the barrier. The counterpart of the peak splitting is the sharp oscillations in the conductance profile. Furthermore, some oscillations for the multiple barriers are so sharp that the structure may be used as an excellent sensor.

关键词： velocity modulation periodicity peak splitting sharp oscillations

Adsorption and Electronic Structure of Sr and Ag Atoms on Graphite Surfaces: aFirst-Principles Study

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Chinese Physics Letters 2013年第6期30卷 169-173页

作者： LUO Xiao-Feng FANG Chao LI Xin LAI Wen-Sheng SUN Li-Feng LIANG Tong-Xiang Advanced Material Laboratory School of Materials Science and EngineeringTsinghua UniversityBeijing 100084 beijing Key Laboratory of Fine Ceramics Institute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084

The adsorption behaviors of radioactive strontium and silver nuclides on the graphite surface in a high-temperature gas-cooled reactor are studied by first-principles theory using generalized gradient approximation(GGA)and local density approximation(LDA)*** turns out that Sr prefers to be absorbed at the hollow of the carbon hexagonal cell by 0.54 eV(GGA),while Ag likes to sit right above the carbon atom with an adsorption energy of almost zero(GGA)and 0.45 eV(LDA).Electronic structure analysis reveals that Sr donates its partial electrons of the 4𝑝and 5𝑠states to the graphite substrate,while Ag on graphite is a physical adsorption without any electron transfer.

关键词： adsorption approximation Adsorption