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Unconventional phase transition of phase-change-memory materials for optical data storage

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chinese Physics B 2019年第10期28卷 73-82页

作者： nian-Ke Chen xian-Bin Li State Key Laboratory of Integrated Optoelectronics College of Electronic Science and Engineering Jilin University

Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing. The light-induced phase transition is the key for this technology. Traditional understanding on the role of light is the heating effect. Generally, the RESET operation of phase-change memory is believed to be a melt-quenching-amorphization process. However, some recent experimental and theoretical investigations have revealed that ultrafast laser can manipulate the structures of phase-change materials by non-thermal effects and induces unconventional phase transitions including solid-to-solid amorphization and order-to-order phase transitions. Compared with the conventional thermal amorphization,these transitions have potential superiors such as faster speed, better endurance, and low power consumption. This article summarizes some recent progress of experimental observations and theoretical analyses on these unconventional phase transitions. The discussions mainly focus on the physical mechanism at atomic scale to provide guidance to control the phase transitions for optical storage. Outlook on some possible applications of the non-thermal phase transition is also presented to develop new types of devices.

关键词： light-matter interaction phase-change memory non-thermal phase transition optical data storage

Theoretical Study on the Stable Structures and Aromaticities for Pnictogen Dianionic Sb4^2-, Bi4^2-, and （SbBi）2^2- Clusters

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chinese Journal of Chemical Physics 2009年第1期22卷 75-81页

作者： Xing-bao Wang xian-xing chi School of Physics and Electronic Information Wenzhou University Wenzhou 325027 China

Through the theoretical calculation of structural optimization, vibrational frequencies and atomization energies with one method of density functional theory （B3LYP） and two post- Hartree-Fock approaches （MP2, CCSD（T））, several stable isomers for new three pnictogen dianionic Sb4^2-, Bi4^2-, and （SbBi）2^2- species were determined. For two homoatomic Sb4^2- and Bi4^2- species, there are three stable isomers： square （D4h）, roof-shaped （C2v-1）, and C2v-2 structure with the square isomer being the ground state. For the heteroatomic dian- ionic （SbBi）2^2- species, there are also three stable isomers： rhombus （D2h）, roof-shaped （C1）, and C2v structures with the rhombic isomer being the ground state. The calculated NICS values show that nucleus-independent chemical shifts （NICS） values of roof-shaped isomers for Sb4^2-, Bi4^2-, and （SbBi）2^2- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters. The aromaticity for the two stable roof-shaped and square isomers are preliminarily explained and discussed with MO analysis.

关键词： Pnictogen cluster Ab initio Aromaticity Nucleus-independent chemical shift

Spin Filtering in a Rashba Electron Waveguide Induced by Edge Disorder

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chinese Physics Letters 2012年第8期29卷 209-212页

作者： XIAO xian-Bo LI Fei LIU nian-Hua Institute for Advanced Study Nanchang UniversityNanchang 330031 School of Computer Jiangxi University of Traditional Chinese MedicineNanchang 330004

We theoretically study the spin-dependent electron transport in a Rashba electron waveguide with rough edges,attached to ideal leads without spin-orbit *** influence of the edge disorder on the charge and spin conductances is clarified by using the spin-resolved lattice Green function *** is found that a spin-polarized current can be generated in the output lead and its spin polarization can be manipulated by varying the waveguide *** underlying physics is attributed to the broken longitudinal symmetry and the spin-dependent quantum interference induced by the rough *** results may provide a new method to design a spin filter without using magnetic materials or applying a magnetic field.

关键词： waveguide polarization Waveguide

Recent Progress in Mass Spectrometry-based Metabolomics for Colorectal Cancer

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Chemical Research in chinese Universities 2022年第4期38卷 886-893页

作者： XIAO Chulei chi Quan WANG xian Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission School of Chemistry and Materials ScienceSouth-Central Minzu UniversityWuhan430074P.R.China

Metabolomics,one of the latest omics technologies,is employed to reveal overall metabolic trajectories,identify disease causative mechanisms and provide information for preventive diagnosis and drug *** is a disease known to alter cellular metabolism and so metabolomics can play an important role in the early diagnosis of cancer and in the evaluation of medical interventions and treatments for *** metabolomics studies rely on high-sensitive and high-throughput mass spectrometry *** recent years,various mass spectrometry(MS)methodologies have been developed and enriched the scope of metabolite detection,contributing to disease studies,such as diabetes,cancer,and *** cancer is the third most diagnosed cancer worldwide and its incidence ranked third in *** review focuses on the mass spectrometry technologies in metabolomics and summarizes the progress of metabolomics research in colorectal cancer.

关键词： Metabolomics Mass spectrometry Colorectal cancer Biomarker

An empirical approach for predicting burden velocities in rock blasting

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第4期13卷 767-773页

作者： Zong-xian Zhang Li-Yuan chi Changping Yi Oulu Mining School University of OuluOuluFI-90014Finland State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina Division of Mining and Geotechnical Engineering Lulea University of TechnologyLuleaSweden

An analytical relation between burden velocity and ratio of burden to blasthole diameter is developed in this *** relation is found to be consistent with the measured burden velocities of all 37 full-scale blasts found from published *** blasts include single-hole blasts,multi-hole blasts,and simultaneously-initiated blasts with various borehole diameters such as 64 mm,76 mm,92 mm,115 mm,142 mm and 310 *** boreholes were fully *** agreement between measured and calculated burden velocities demonstrates that this relation can be used to predict the burden velocity of a wide range of full-scale blast with fully-coupled explosive charge and help to determine a correct delay time between adjacent holes or rows in various full-scale blasts involved in tunnelling(or drifting),surface and underground mining production blasts and underground opening slot *** addition,this theoretical relation is found to agree with the measured burden velocities of 9 laboratory small-scale blasts to a certain *** predict the burden velocity of a small-scale blast,a further study or modification to the relation is necessary by using more small-scale blasts in the future.

关键词： Burden velocity Rock blasting Kinetic energy Delay time Tunnelling Minin

Separation and enrichment mechanism of C54–TiSi_(2) from hypoeutectic Ti–65 wt.%Si alloy during directional solidification via alternating electromagnetic fields

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Journal of Iron and Steel Research International 2021年第1期28卷 29-37页

作者： Kui‑song Zhu Jing‑fei Hu Wen‑hui Ma Kui‑xian Wei Yong‑nian Dai The National Engineering Laboratory for Vacuum Metallurgy State Key Laboratory of Complex Nonferrous Metal Resources Clean UtilizationKunming University of Science and TechnologyKunming 650093YunnanChina College of Vanadium and Titanium Panzhihua UniversityPanzhihua 617000SichuanChina Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province Engineering Research Center for Silicon Metallurgy and Silicon Materials of Yunnan Provincial UniversitiesKunming University of Science and TechnologyKunming 650093YunnanChina

The effects of directional solidification parameters and the coupling of directional solidification parameters and alternating electromagnetic fields on separation and enrichment of the C54–TiSi2 phase were investigated in a directionally solidified hypoeutectic Ti–65 wt.%Si *** results indicated that by increasing the pull-down velocity at a given position within the ingot,the cooling rate,growth rate,and temperature gradient of ingot could be *** a pull-down velocity near 5μm/s,the temperature gradient,cooling rate,and growth rate decreased with increasing the thickness of the C54–TiSi2-rich *** fields enhanced mass transfer at pull-down velocities of 5,10,15,and 20μm/s,with resulting enriched layer thicknesses of 15,10,10,and 5 mm,*** increasing the percentage of Ti in the Ti–Si alloy from 25 to 35 wt.%,the thickness of the C54–TiSi2-rich layer was increased from 2.5 to 3.3 ***,the maximum C54–TiSi2 content obtained experimentally in this layer decreased from 92.06 to 79.49 mass%.

关键词： Ti–Si alloy Directional solidification Electromagnetic field Separation C54–TiSi2

Characterization of the new scintillator Cs2LiYCl6:Ce3+

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Nuclear Science and Techniques 2018年第1期29卷 39-44页

作者： Kui-nian Li xian-Peng Zhang Qiang Gui Peng Jin Geng Tian Northwest Institute of Nuclear Technology Xi’an 710024China School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an 710049 China Beijing Glass Research Institute Beijing 101111 China

The first domestic inorganic scintillator, Cs_2LiYCl_6:Ce^(3+)(CLYC), was grown at Beijing Glass Research Institute using the vertical Bridgman method. In this work, we evaluated the performance of this new CLYC crystal in terms of its gamma-ray energy resolution and pulse shape discrimination(PSD) capability between neutrons and gamma rays. The decay times associated with different scintillation mechanisms were obtained by fitting decay functions to the neutron and gamma-ray waveform structures. We found an energy resolution of * 4.5% for 662-ke V gamma rays and efficient neutron/gamma PSD with a figure of merit of * 2.6. Under gamma-ray excitation, there is an ultrafast scintillation mechanism in CLYC with a decay time of approximately 2 ns, whereas there is no evidence of ultrafast decay under thermal neutron excitation. This work contributes to the promotion of domestic development of CLYC.

关键词： Cs2LiYCl6:Ce3+ Energy resolution Pulse shape discrimination Decay time Thermal neutrons

Ar-Ar Dating of Baimazhai Nickel-Copper-(PGE) Sulphide Deposit and Its Significance, Southeast Yunnan Province, china

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Journal of china University of Mining and Technology 2006年第2期16卷 200-205页

作者： ZHANG Xue-shu QIN De-xian Franco Pirajno nian Hong Department of Geological Science Kunming University of Science and Technology Kunming Yunnan 650093 China Yunnan Non-ferrous Metals Geological Bureau Kunming Yunnan 650051 China Geological Survey of Western Australia 100 Plain Street WA 6004 Australia

The Baimazhai Ni-Cu- (PGE) sulphide deposit in southeast Yunnan Province is hosted in mafic-ultramafic intrusions associated with the Permian Emeishan large igneous province. The deposit, one of several in the province, exhibits field and petrographic features suggestive of post-magmatic modification. The mafic-ultramafic intrusions that host the Baimazhai sulphide ores show near-pervasive to pervasive hydrothermal alteration, with the sulphides be- ing spatially associated with hydrothermal minerals such as biotite, amphibole and chlorite. This intimate association suggests that the sulphide ores were subjected to deformational and hydrothermal redistribution and textural changes resulting in disseminated and brecciated ores. Geochemically the Baimazhai sulphide ores are enriched in Cu, Pd and Au which, according to published studies, reflects the action of hydrothermal fluids. Interestingly, Ar-Ar age data yielded plateau ages of about 160-170 Ma, which also supports the modification features of the sulfide ores.

关键词： mafic-ultramafic intrusions Ni-Cu-(PGE) mineralization Ar-Ar dating sulphide remobilization Baimazhai

Multi-microgrid Energy Management Systems: Architecture, Communication, and Scheduling Strategies

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Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 463-476页

作者： Bin Zhou Jianting Zou chi Yung Chung Huaizhi Wang nian Liu Nikolai Voropai Daosen Xu the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China the Department of Electrical and Computer Engineering University of SaskatchewanSaskatoonSK S7N5A9Canada the College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China the Melentiev Energy Systems Institute of Siberian Branch of the Russian Academy of Sciences Irkutsk 664033Russia

The increasing penetration of various distributed and renewable energy resources at the consumption premises,along with the advanced metering,control and communication technologies,promotes a transition on the structure of traditional distribution systems towards cyber-physical multi-microgrids(MMGs).The networked MMG system is an interconnected cluster of distributed generators,energy storage as well as controllable loads in a distribution *** its operation complexity can be decomposed to decrease the burdens of communi-cation and control with a decentralized ***,the multi-microgrid energy management system(MIVIGEIV1S)plays a significant role in improving energy efficiency,power quality and reliability of distribution systems,especially in enhancing system resiliency during contingencies.A comprehensive overview on typical functionalities and architectures of MMGEMS is ***,the emerging communication technologies for information monitoring and interaction among MMG clusters are ***,various energy scheduling and control strategies of MMGs for interactive energy trading,multi-energy management,and resilient operations are thoroughly analyzed and ***,some challenges with great importance in the future research are presented.

关键词： Energy management system(EMS) microgrid communication renewable energy multi-energy system