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Communications in Theoretical Physics 2007年第6期47卷 1143-1144页

作者： chang Da-wei Faculty of Mathematics and Information Science Shaanxi Normal University Xi＇an 710062 China

In this note, we would like to point out that （i） of Corollary 1 given by Zhang et al. （cf Commun. Theor. Phys. 39 （2003） 381） is incorrect in general.

关键词： Hopfield neural networks distributed delays equilibrium point globally exponential stability

Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1133-1139页

作者： YU Jian-chang HU Sheng-wei College of Material Science and Engineering Fuzhou University Fuzhou 350002 China

Study on nanomaterials has attracted great interests in recent years. In this article, zirconia nanocrystallites of different structures have been successfully synthesized via hydrothermal methods with cationic surfactant （CTAB） and anionic surfactant （SDS）, respectively. Differential Scanning Calorimeter （DSC-TG）, X-ray Diffractometer （XRD）, Transmission Electron Microscope （TEM）, Ultraviolet-Visible （UV-vis） and N2 adsorption-desorption analyses are used for their structure characteristics. The results show that the cationic surfactant has a distinctive direction effect on the formation of zirconia nanocrystallites, while the anionic surfactant has a self-assembly synergistic effect on them. The sample synthesized with the cationic surfactant presents good dispersion with the main phase of tetragonal zirconia, and the average nanocrystal size is around 15 nm after calcination at 500 ℃. While the sample synthesized with the anionic surfactant exhibits a worm-like mesoporous structure with pure tetragonal phase after calcination at 500 ℃ and with good thermal stability.

关键词： cationic surfactant anionic surfactant zirconia nanocrystallites,mesoporous zirconia

A gauge theory for two-band model of Chern insulators and induced topological defects

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Communications in Theoretical Physics 2022年第1期74卷 124-133页

作者： Zhi-Wen chang wei-chang Hao Xin Liu Institute of Theoretical Physics Faculty of SciencesBeijing University of TechnologyBeijing 100124China School of Physics Beihang UniversityBeijing 100191China

In this paper a gauge theory is proposed for the two-band model of Chern *** on the so-calle't Hooft monopole model,a U(1)Maxwell electromagnetic sub-field is constructed from an SU(2)gauge field,from which arise two types of topological defects,monopoles and e2 *** focus on the topological number in the Hall conductance σ_(xy)=e^(2)/hC,where C is the Chern *** is discovered that in the monopole case C is indeterminate,while in the meron case C takes different values,due to a varying on-site energy *** a typical example,we apply this method to the square lattice and compute the winding numbers(topological charges)of the defects;the C-evaluations we obtain reproduce the results of the usual ***,based on the gauge theory we propose a new model to obtain the high Chern numbers|C|=2,4.

关键词： Chern insulator Chern number monopole meron

Composition and distribution of NSO compounds in two different shales at the early maturity stage characterized by negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry

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Petroleum Science 2018年第2期15卷 289-296页

作者： chang-wei Ke Yao-Hui Xu Xiang-Chun chang wei-Bin Liu Key Laboratory of Exploration Technologies for Oil and Gas Resources (Yangtze University) Ministry of Education College of Resources and Environment Yangtze University College of Earth Science and Engineering Shandong University of Science and Technology Oil and Gas Survey China Geological Survey

Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based on Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR-MS） and GC/MS analyses, the molecular compositions of NSO compounds in extracts from the Permian Dalong Formation, Sichuan Basin and the Permian Lucaogou Formation, Junggar Basin in China were compared. Analyses of types of heteroatoms present （S~, $2, $3, OS, OS2, 02S, NS, and NOS compounds） suggest that marine shales from the Dalong Formation are mainly composed of carboxylic acids （02 com- pounds） with a high abundance of fatty acids, indicating a marine phytoplankton organic source. However, lacustrine shales from the Lucaogou Formation are dominated by pyrrolic compounds （N1 compounds） with abundant dibenzocar- bazole. It suggests that the organic source materials may be derived from lower aquatic organisms and lacustrine algae. Overall, FT-ICR-MS has potential for applications in analyses and determination of depositional environments and organic sources in petroleum geology.

关键词： Fourier transform ion cyclotron resonance mass spectrometry Dalong Formation Lucaogou Formation NSO compounds Sedimentary environment

Impacts of the COVID-19 pandemic on vegetable production and countermeasures from an agricultural insurance perspective

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Journal of Integrative Agriculture 2020年第12期19卷 2866-2876页

作者： GU Hai-ying WANG chang-wei Antai College of Economics and Management Shanghai Jiao Tong UniversityShanghai 200030P.R.China Institute of Industry Research Shanghai Jiao Tong UniversityShanghai 200030P.R.China Institute of Finance and Economics Shanghai University of Finance and EconomicsShanghai 200433P.R.China

In the face of the corona virus disease 2019(COVID-19)pandemic,it is essential to stabilize the security of urban“shopping baskets”.Through a survey and interviews with 46 agricultural cooperatives in Shanghai,this paper analyzes the impact of the pandemic on vegetable production and offers suggestions on agricultural *** research results show that:(1)the pandemic has impacted almost all stages of the vegetable supply chain but has had a greater impact on the sales stage;(2)the market risks of vegetable production have increased significantly,and the gap between the field price and the market price has *** sales price difference between traditional channels and e-commerce is notable;(3)farmers’incomes have generally declined due to the COVID-19 pandemic,and traditional small-scale farmers have suffered more losses;and(4)agricultural insurance plays an important role in stabilizing the supply of vegetables to the *** minimize the impact of the pandemic on vegetable production and to stabilize both urban“shopping baskets”and farmers’incomes,it is necessary to further improve agricultural insurance,especially to provide insurance against market risks.

关键词： COVID-19 vegetable supply chain agricultural insurance market risks

A review on the structure-performance relationship of the catalysts during propane dehydrogenation reaction

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Petroleum Science 2022年第2期19卷 819-838页

作者： Bohan Feng Yue-chang wei wei-Yu Song Chun-Ming Xu State Key Laboratory of Heavy Oil Processing College of ScienceChina University of PetroleumBeijing102249People's Republic of China

Dehydrogenation of propane(PDH)technology is one of the most promising on-purpose technologies to solve supply-demand unbalance of *** industrial catalysts for PDH,such as Pt-and Cr-based catalysts,still have their own limitation in expensive price and security ***,a deep understanding into the structure-performance relationship of the catalysts during PDH reaction is necessary to achieve innovation in advanced high-efficient *** this review,we focused on discussion of structure-performance relationship of catalysts in *** on analysis of reaction mechanism and nature of active sites,we detailed interaction mechanism between structure of active sites and catalytic performance in metal catalysts and oxide *** relationship between coke deposition,co-feeding gas,catalytic activity and nanostructure of the catalysts are also *** these discussions on the relationship between structure and performances,we try to provide the insights into microstructure of active sites in PDH and the rational guidance for future design and development of PDH catalysts.

关键词： Dehydrogenation of propane Metal catalysts Oxide catalysts Structure-performance relationship Active site Reaction mechanism

Validity of extracting photoionization time delay from the first moment of streaking spectrogram

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Chinese Physics B 2019年第1期28卷 330-339页

作者： chang-Li wei Xi Zhao School of Physics and Electronics Qiannan Normal College for Nationalities Department of Physics Kansas State University

Photoionization time delays have been studied in many streaking experiments in which an attosecond pulse is used to ionize the atomic or solid state target in the presence of a dressing infrared laser field. Among the methods of extracting the time delay from the streaking spectrogram, the simplest one is to calculate the first moment of the spectrogram and to measure its offset relative to the vector potential of the infrared field. The first moment method has been used in many theoretical simulations and analysis of experimental data, but the meaning of this offset needs to be investigated. We simulate the spectrograms and compare the extracted time delay from the first moment with the input Wigner delay. In this study, we show that the first moment method is valid only when the group delay dispersions corresponding to both the spectral phase of the attosecond pulse and the phase of the single-photon transition dipole matrix element of the target are small. Under such circumstance, the electron wave packet behaves like a classical particle and the extracted time delay can be related to a group delay in the photoionization process. To avoid ambiguity and confusion, we also suggest that the photoionization time delay be replaced by photoionization group delay and the Wigner time delay be replaced by Wigner group delay.

关键词： photoionization time delay strong laser field attosecond science first moment

Anatomizing the Ocean's Role in Maintaining the Pacific Decadal Variability

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Advances in Atmospheric Sciences 2014年第3期31卷 611-623页

作者： Jia-Yuh YU Cheng-wei chang Department of Atmospheric Sciences Chinese Culture University Graduate Institute of Earth Science Chinese Culture University

ABSTRACT The role of ocean dynamics in maintaining the Pacific Decadal Variability （PDV） was investigated based on simulation results from the Parallel Ocean Program （POP） ocean general circulation model developed at the Los Alamos National Laboratory （LANL）. A long-term control simulation of the LANL-POP model forced by a reconstructed coupled wind stress field over the period 1949-2001 showed that the ocean model not only simulates a reasonable climatology, but also produces a climate variability pattem very similar to observed PDV. In the Equatorial Pacific （EP） region, the decadal warming is confined in the thin surface layer. Beneath the surface, a strong compensating cooling, accompanied by a basin-wide-scale overturning circulation in opposition to the mean flow, occurs in the thermocline layer. In the North Pacific （NP） region, the decadal variability nonetheless exhibits a relatively monotonous pattern, characterized by the dominance of anomalous cooling and eastward flows. A term balance analysis of the perturbation heat budget equation was conducted to highlight the ocean＇s role in main- taining the PDV-like variability over the EP and NP regions. The analyses showed that strong oceanic adjustment must occur in the equatorial thermocline in association with the anomalous overturning circulation in order to maintain the PDV-like variability, including a flattening of the equatorial thermocline slpoe and an enhancement of the upper ocean＇s stratification （stability）, as the climate shifts from a colder regime toward a warmer one. On the other hand, the oceanic response in the extratropical region seems to be confined to the surface layer, without much participation from the subsurface oceanic dynamics.

关键词： Pacific decadal variability term balance analysis perturbation heat budget equation

A power-aware code-compression design for RISC/VLIW architecture

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第8期12卷 629-637页

作者： Che-wei LIN chang Hong LIN wei Jhih WANG Department of Electronic Engineering National Taiwan University of Science and Technology Taiwan 106 Taipei

We studied the architecture of embedded computing systems from the viewpoint of power consumption in memory systems and used a selective-code-compression (SCC) approach to realize our *** on the LZW (Lempel-Ziv-Welch) compression algorithm,we propose a novel cost effective compression and decompression *** goal of our study was to develop a new SCC approach with an extended decision policy based on the prediction of power *** decompression method had to be easily implemented in hardware and to collaborate with the embedded *** hardware implementation of our decompression engine uses the TSMC 0.18μm-2p6m model and its cell-based *** calculate power consumption more accurately,we used a static analysis method to estimate the power overhead of the decompression *** also used variable sized branch blocks and considered several features of very long instruction word (VLIW) processors for our compression,including the instruction level parallelism (ILP) technique and the scheduling of *** code-compression methods are not limited to VLIW machines,and can be applied to other kinds of reduced instruction set computer (RISC) architecture.

关键词： LZW compression Cell-based libraries Instruction level parallelism (ILP) VLIW processors

Prevention of self-harm through early detection of depression among the elderly with permanent pacemaker:a case report

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Journal of Geriatric Cardiology 2021年第4期18卷 312-315页

作者： Yu-wei chang Ju-Yi CHEN Division of Cardiology Department of Internal MedicineNational Cheng Kung University HospitalCollege of MedicineNational Cheng Kung UniversityTaiwanChina

There is consensus regarding the efficacy and safety of permanent pacemakers(PPM) and other cardiac implantable electronic devices. These devices improve the quality of life by reliving symptoms of bradycardia including dizziness, fatigue and exercise intolerance. The decision to implant a PPM is often made at the time of the initial encounter with the patient, such as when symptomatic bradyarrhythmia is first diagnosed.

关键词： permanent cardiac implant