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Weak Signal Frequency Detection Based on a Fractional-Order Bistable System

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Chinese Physics Letters 2012年第6期29卷 13-16页

作者： he gui-Tian LUO Mao-Kang Department of Mathematics Sichuan UniversityChengdu 610064

We apply spectral power amplification to quantifying and investigating the phenomenon of stochastic resonance in fractional-order ***,the frequency of the weak mixed signal is detected by a stochastic resonance mechanism together with a power *** corresponding numerical results demonstrate the effectiveness of the proposed methods.

关键词： spectrum methods stochastic

Characteristics of the main polluting trace elements in the water environment of mining subsidence pools

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Journal of China University of Mining and Technology 2008年第3期18卷 362-367页

作者： YAO En-qin gui he-rong Department of Resources and Engineering Anhui University of Science and TechnologyHuainan Anhui 232001 China Suzhou College Suzhou Anhui 234000 China

Mining subsidence pools are water bodies formed by soil subsidence near mines. We studied the impact the surrounding coal production activities and power plants have on these waters by measuring the concentrations of harmful trace elements in these waters. The concentration of the four elements F, Hg, Se and As increased by 0.92%, 0.78%, 0.70% and 0.81%, respectively, in the Datong mining subsidence pool from November 2004 to November 2006. The four elements increased by 1.58%, 1.23%, 1.08% and 0.92%, respectively, in the Xie’er mining subsidence pool and 1.16%, 1.06%, 1.02% and 1.01%, respectively, in the Pansan mining subsidence pool over the same time period. The absolute levels of F, Hg, Se and As in the pool are related to the background levels of the elements. A close relationship between nearby coal mines and power plants and increasing levels of the measured elements is noted.

关键词： mining subsidence pool trace elements coal mine water environment

The measurement of time spent outdoors in child myopia research： a systematic review

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International Journal of Ophthalmology(English edition) 2018年第6期11卷 1045-1052页

作者： Jing Wang Xian-gui he Xun Xu Department of Ophthalmology Shanghai General Hospital Shanghai Jiao Tong University Shanghai 200080 China Shanghai Key Laboratory of Ocular Fundus Diseases Shanghai General Hospital Shanghai Jiao Tong University Shanghai 200080 China Shanghai Engineering Center for Visual Science and Photomedicine Shanghai 200080 China Department of Eye Disease Prevention and Treatment Shanghai Eye Disease Prevention and Treatment Center Shanghai Eye Hospital Shanghai 200040 China Department of Matemal and Child health School of Public Health Key Laboratory of Public Health Safety Ministry of Education Fudan University Shanghai 200032 China

The purpose of this article is to summarize the methods most commonly used to measure time spent outdoors and provide a comprehensive review of time and activity recording methods with the aim of encouraging the development of new methods. PubMed, Embase and the Cochrane Library were searched from Jan. 1st, 1990 to Aug. 31th, 2017. Studies including the following specific terms： “outdoor”, “outside”, “outdoor activity”, “outside activity”, “outdoor time”, “outside time”, and “outdoor AND measurement of time spent outdoors” were considered for this review. In total, three kinds of outdoor time measurements were discussed. Questionnaires have the longest history and are the most thoroughly revised instruments for assessing time spent outdoors, but recall bias is their most substantial drawback. Global positioning system （GPS） tracking can distinguish between indoor and outdoor locations, but its utility is limited due to several factors such as subject compatibility. Light exposure measurement devices are newly emerging, but all of these devices require good subject cooperation. Further efforts and exploration are needed to develop better methods and new tools to record exposure to the outdoors in real time. Moreover, inventing a new device by combining two or more types of devices mentioned above and using the latest technology of en ergy supplementation and autoswitching may make the best use of the advantages and bypass the disadvantages of each tool.

关键词： myopia outdoor (activity) time questionnaire global positioning system light exposure

Multi-indicator assessment of water environment in government environmental auditing

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Journal of Environmental Sciences 2007年第4期19卷 494-501页

作者： he gui-zhen LU Yong-long MA Hua WANG Xiao-long Research Centre for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. Graduate University of the Chinese Academy of Sciences Beijing 100039 China

This study focused on a multi-indicator assessment methodology for governmental environmental auditing of water protection programs. The environmental status of Wuli Lake in China was assessed using the global indicators （driver-status-response） developed by the Commission on Sustainable Development, and four additional indicators proposed by the author： water quality, pollution load, aquatic ecosystem status, and lake sediment deposition. Various hydrological, chemical, biological and environmental parameters were used to estimate the values of the indicators for assessment of environmental status of the lake based on time series data sets for twenty years. The indicators proposed can be customized to meeting the needs for particular assessment of water protection programs. This method can be used to evaluate the performance of national environmental protection programs and provide technical support for environmental auditors.

关键词： environmental auditing environmental indicators pollution load lake ecosystem state assessment

Photoelectron Imaging Spectroscopy of ZrO-Diatomic Anion

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Chinese Journal of Chemical Physics 2015年第4期28卷 -页

作者： Qing-yu Liu Lian-rui Hu Hui Chen Sheng-gui he Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190China Beijing National Laboratory for Molecular Sciences Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

The diatomic ZrO? anion has been prepared by laser ablation and studied by photoelectron imaging spectroscopy combined with quantum chemistry calculations. The observed photoelectron spectra can be well assigned on the basis of reported optical spectroscopy and high-level ab initio calculations. The ground state of ZrO? is a 2Δ state with spin-orbit splitting of 578±12 cm?1. The electron affinity of ZrO is 1.249±0.005 eV. For the first time, the c3∑? state of ZrO has been experimentally observed at 13316±24 cm?1 with respect to the X1∑+ground state. A comparison between ZrO and the isoelectronic molecule NbN has been made.

关键词： Diatomic molecules Electronic structure Spin-orbit splitting Photoelectron imaging spectroscopy ab initio calculations

Influence of impurity hydrogen on the structure and properties of bulk Li and pressure effects

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Science China(Physics,Mechanics & Astronomy) 2006年第6期49卷 740-747页

作者： LIU Zhiming MA Yanming he Zhi gui Tian he Wenjiong LIU Bingbing ZOU Guangtian National Laboratory of Superhard Material Jilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China National Laboratory of Superhard MaterialJilin UniversityChangchun130012China

The structure and properties of a 16-atom body-centered cubic lithium cell with an interstitial hydrogen atom are studied using a pseudopotential-plane-wave method within the density functional theory at 0 K and high pressures. The host lattice is dra-matically distorted by the introduction of H. Although the hydrogen atom is stable at the tetragonal site in perfect bcc host lattice,it favors the octahedral site formed by six non-equivalent Li atoms after full relaxation of the cell,showing P4/mmm symmetry within the pressures ranging from 0 to 6 GPa. The lattice ratio (a/c) changes irregularly with external pressure at about 3 GPa. The hydrogen band lies in the bottom of the valence band,separated by a gap from the metallic bands,illustrating the electronegativity of hydrogen. High reflectivity in the low frequency area induced by the impurity hydrogen is observed when only interband transitions are taken account of. A dip in reflectivity due to parallel band transitions is observed at ～0.4 eV. Another dip at ～4.3 eV appears when external pressure increases over 4 GPa.

关键词： first principles,lithium,impurity and pressure effect,dielectric response.

Quality Competence: a Source of Sustained Competitive Advantage

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The Journal of China Universities of Posts and Telecommunications 2006年第1期13卷 104-108页

作者： WANG Zhi-yu QIU Yan-lin gui Shi-he Management Department The First Aeronautical College of Air Force Xinyang 464000 P.R. China Economics and Management School Wuhan University Wuhan 430072 P. R China

This paper reviews the development of quality management and competitive advantage, and explores the notion of strategic status of quality as a source of sustained competitive advantage. In addition, the paper presents a number of suggestions to the Chinese telecommunications industry on the development of quality competence in order to sustain an advantage over foreign competitors.

关键词： quality competence resource-based view competitive advantage

Experimental and Theoretical Study of Reactions between Manganese Oxide Cluster Cations and Hydrogen Sulfide

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Chinese Journal of Chemical Physics 2013年第6期26卷 679-686,I0003,I0004页

作者： Mei-ye Jia Sheng-gui he Mao-fa Ge Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

Manganese oxide cluster cations Mnm180n＋ were prepared by laser ablation and reacted with hydrogen sulfide （H2S） in a fast flow reactor under thermal collision conditions. A time-of-flight mass spectrometer was used to detect the cluster distributions before and after the interactions with H2S. The experiments suggest that oxygen-for-sulfur （O/S） ex- change reaction to release water took place in the reactor for most of the manganese oxide cluster cations： MnmlSOn＋＋H2S→Mnm18On-1S＋＋H218O. Density functional theory cal- culations were performed for reaction mechanisms of Mn202＋＋H2S, Mn203＋＋H2S, and Mn204＋＋H2S. The computational results indicate these O/S exchange reactions are both thermodynamically and kinetically favorable, thus in good agreement with the experimental observations. The O/S exchange reactions identified in this gas-phase cluster study parallel similar behavior of related condensed phase reaction systems.

关键词： Cluster Oxygen-for-sulfur exchange Reaction mechanism Mass spectrometry Density functional theory

First-principles theory on electronic structure and floatability of spodumene

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Rare Metals 2014年第6期33卷 742-748页

作者： gui-Chun he Hua-Mei Xiang Wei Jiang Qian Kang Jian-Hua Chen Faculty of Resource and Environmental Engineering Jiangxi University of Science and Technology College of Resources and Metallurgy Guangxi University

The band structure, density of states, Mulliken populations, and frontier orbital of spodumene crystal were calculated using the first-principles method based on the density functional theory（DFT） and further analyzed in detail. The calculation results reveal that the O in spodumene is the most active and easily links with H＋in the water, but the active Li is very low, so it is better to add activator to increase the concentrate grade and recovery rate of spodumene in the flotation process. Si–O bonds in spodumene crystal are mainly covalent, since the covalency of Al–O bonds is stronger than that of Li–O bonds,and minerals dissociate along the weakest Li–O bonds. In addition, the study of the frontier orbital indicates that both O and Si atoms have large contribution to the frontier orbital in the spodumene crystal. Oleate and dodecylamine are used as the collectors of spodumene. The results contribute to the understanding of crystal structures of spodumene, and can be used in guiding related practical applications.

关键词： Spodumene Electronic structure Floatability First-principles method Frontier orbital