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A New Criterion on k-Normal Elements over Finite Fields

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Chinese Annals of Mathematics,Series B 2020年第5期41卷 665-678页

作者： Aixian zhang Keqin FENG Department of Mathematical Sciences Xi’an University of TechnologyXi’an 710054China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The notion of normal elements for finite fields extension was generalized as k-normal elements by Huczynska et al.(2013).Several methods to construct k-normal elements were presented by Alizadah et al.(2016)and Huczynska et al.(2013),and the criteria on k-normal elements were given by Alizadah et al.(2016)and Antonio et al.(2018).In the paper by Huczynska,S.,Mullen,G.,Panario,*** Thomson,D.(2013),the number of k-normal elements for a fixed finite field extension was calculated and *** this paper the authors present a new criterion on k-normal elements by using idempotents and show some *** criterion was given for usual normal elements before by zhang et al.(2015).

关键词： Normal basis Finite field Idempotent Linearized polynomial Gauss

Special issue on electrochemical energy storage and conversion

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Frontiers in Energy 2024年第2期18卷 125-127页

作者： Yun ZHENG Gaixia zhang Sixu DENG Jiujun zhang Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China Department of Electrical Engineering École de Technologie Supérieure(ÉTS)Universitédu QuébecMontréalH3C 1K3Canada Department of Chemical and Materials Engineering Concordia UniversityMontrealQC H3G 1M8Canada

The escalating global consumption of fossil fuels has significantly elevated the levels of CO_(2)in the atmosphere,leading to an undesirable global energy crisis and environmental *** deployment of renewable energy resources is crucial to mitigate these *** recent years,there has been noteworthy progress in electrochemical energy storage and conversion techniques and devices,including hydrogen energy and fuel cells,advanced energy storage and power batteries,and CO_(2)electrochemical conversion and utilization.

关键词： electrochemical energy elevated

Effects of florfenicol exposure on growth,development and antioxidant capacity of flounder Paralichthys olivaceus larvae at different developmental stages

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Journal of Oceanology and Limnology 2020年第2期38卷 550-559页

作者： GUO Rui zhang Yingqi zhang Xianyu zhang Qian CHENG Rui MD MOSTAFIZUR Rahman LIU Ying College of Marine Science and Environment Dalian Ocean UniversityDalian 116023China Liaoning Aquacultural Engineering R&D Center Dalian 116023China

Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic ***(FLO)is one of the most commonly used antibiotics in aquaculture,and extensively used to substitute chloramphenicol with its strong sterilization and low adverse ef *** this study,flounder Paralichthys olivaceus,an important economic fish species in seawater was used as an experimental *** exposure concentrations of FLO(including environmentrelated concentrations)were set at 0,0.01,0.1,1,and 10 mg/*** fects of FLO exposure for 168 h on growth and development,motor behavior,antioxidant enzyme activity,malondialdehyde(MDA)content,and thyroid hormone level of *** larvae were studied in pre-larvae(1 dpf)and post-larvae(20 dpf).The results show that the short-term FLO exposure could promote the larvae growth to some degrees,but inhibit them as the exposure time *** pre-larvae,FLO at 0.01 mg/L could stimulate the motor nerve system and increase the swimming ability,but inhibited it at 1 mg/*** the increasing dosage of FLO,the superoxide dismutase(SOD)and MDA contents were elevated,reaching the maximum in the 1 mg/L FLO *** pre-larvae were more sensitive than the post-larvae to FLO in the environment,and the growth and immune resistance could be damaged with long ***-larvae were more tolerant to external pollutants,FLO at 1 mg/L could promote the motor behavior and reduce SOD and MDA ***,FLO can be used as an antibiotic at a proper concentration but as a drug to prevent disease in a long-term way.

关键词： florfenicol Paralichthys olivaceus larvae growth and development motor behavior antioxidant capacity

Thermal Stability of Fe_2O_3 Nanowires

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Journal of Materials Science & Technology 2008年第4期24卷 594-596页

作者： Xiongdian zhang Qin HAN Zhao DONG Yingying XU Han zhang State Key Laboratory for Mesoscopic Physics Department of Physics Peking University. Beijing 100871 China

The thermal stability of α-Fe203 and γ-Fe2O3 nanowires was studied by post annealing the samples at different temperatures. Before and after annealing, the samples were characterized by X-ray diffraction and scanning electron microscopy. The α-Fe2O3 nanowires are stable at the temperatures up to 600℃, and the crystalline structure becomes more perfect after annealing. This behavior supplies a way to improve the quality of the α-Fe2O3 nanowires. The γ-Fe2O3 nanowires become unstable when annealed at 350℃. Raman spectra of both nanowires have been measured, which also indicate that the γ-Fe203 nanowires are transformed into α-Fe2O3 under the strong laser beam.

关键词： Fe2O3 nanowire Thermal stability Structural transformation

Dielectric breakdown properties of Al-air mixtures

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Plasma Science and Technology 2021年第5期23卷 59-65页

作者： Xiyuan CAI Xiao zhang Junyong LU Sai TAN Yongsheng zhang Guanxiang zhang National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhan 430033People's Republic of China

In order to investigate the influence of aluminum vapor on the breakdown performance of air,this paper makes a study of the dielectric breakdown characteristics of Al-air mixture in the temperature range of 300-5000 K at atmospheric pressure.A Boltzmann analysis method is used to deal with the electron energy distribution function(EEDF),the reduced ionization coefficients(α/N),the reduced attachment coefficients(η/N)and the critical reduced breakdown strength((E/N)cr)so as to explore the influence of temperature and mixing ratio on the dielectric breakdown *** the temperature range of 300-2000 K,the property of the mixture is mainly determined by the mixing proportion of aluminum vapor because the composition of particles remains *** the temperature range of 2000-2500 K,the decomposition of Al2O_(2)leads to the increase of aluminum oxides and NO,and a rise in the percentage of highenergy electrons as well as the increment ofα/***,the joint action of O_(2)and NO makesη/N increase first and then decrease,and(E/N)crgoes down to a smaller temperature *** increase in the proportion of aluminum vapor causes(E/N)crto decrease in the low-temperature region and to increase in the high-temperature region,which will reduce the transition between these two temperature regions.

关键词： aluminum vapor arc discharges Boltzmann analysis dielectric properties electromagnetic rail launch muzzle arc

tructure and Composition of Crystalline Carbon Nitride Films Synthesized by Microwave Plasma Chemical Vapor Deposition

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 282-285页

作者： Yongping zhang Yousong Gu Xiangrong Chang Zhongzhuo Tian Xiufang zhang Material Science and Engineering School University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Vacuum Physics Institute of physicsChinese

Crystalline carbon nitride thin films were prepared on Si (100) substrates by a microwave plasma chemical vapor deposition method, using CH4/N2 as precursor gases. The surface morphologies of the carbon nitride films deposited on Si substrate at 830℃ are consisted of hexagonal crystalline rods. The effect of substrate temperature on the formation of carbon nitrides was investigated. X-ray photoelectron spectroscopy analysis indicated that the maximum value of N/C in atomic ratio in the films deposited at a substrate temperature of 830℃ is 1 .20, which is close to the stoichiometric value of C3N4. The X-ray diffraction pattern of the films deposited at 830℃ indicates no amorphous phase in the films, which are composed of β- and α-C3N4 phase containing an unidentified C-N phase. Fourier transform infrared spectroscopy supports the existence of C-N covalent bond.

关键词： Crystalline materials

Sawtooth-like oscillations and steady states caused by the m/n=2/1 double tearing mode

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Plasma Science and Technology 2022年第3期24卷 89-97页

作者： Wei zhang Zhiwei MA Haowei zhang Xin WANG Institute for Fusion Theory and Simulation Department of PhysicsZhejiang UniversityHangzhou 310027People's Republic of China

The sawtooth-like oscillations resulting from the m/n=2/1 double tearing mode(DTM)are numerically investigated through the three-dimensional,toroidal,nonlinear resistive-MHD code(CLT).We find that the nonlinear evolution of the m/n=2/1 DTM can lead to sawtooth-like oscillations,which are similar to those driven by the kink *** perpendicular thermal conductivity and the external heating rate can significantly alter the behaviors of the DTM driven sawtooth-like *** a high perpendicular thermal conductivity,the system quickly evolves into a steady state with m/n=2/1 magnetic islands and helical ***,with a low perpendicular thermal conductivity,the system tends to exhibit sawtooth-like *** a sufficiently high or low heating rate,the system exhibits sawtooth-like oscillations,while with an intermediate heating rate,the system quickly evolves into a steady *** the steady state,there exist the non-axisymmetric magnetic field and strong radial flow,and both are with helicity of m/n=2/*** the steady state with m/n=1/1 radial flow,which is beneficial for preventing the helium ash accumulation in the core,the steady state with m/n=2/1 radial flow might also be a good candidate for the advanced steady state operations in future fusion *** also find that the behaviors of the sawtooth-like oscillations are almost independent of tokamak geometry,which implies that the steady state with saturated m/n=2/1 islands might exist in different tokamaks.

关键词： DTM reversed magnetic shear pressure crash sawteeth sawtooth double tearing mode steady state advanced scenario

A quantitative polymerase chain reaction assay for the enumeration of brown tide algae Aureococcus anophagefferens in coastal waters of Qinhuangdao

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Acta Oceanologica Sinica 2015年第2期34卷 132-136页

作者： GUO Hao LIU Yongjian zhang Qi YUAN Xiutang zhang Weiwei zhang Zhifeng Dalian Maritime University Key Laboratory of Coastal Ecology and Environment of State Oceanic Administration National Marine Environmental Monitoring Center College of Fisheries and Life Science Dalian Ocean University

Aureococcus anophagefferens, a small pelagophyte algae, has caused brown tide blooms in coastal waters of Qinhuangdao in recent years, presenting significant negative impacts on the shellfish mariculture industry. Under standard light microscopy, it is visually indistinguishable from other small algae in field samples due to its extremely small size. In this study, quantitative polymerase chain reaction（q PCR） based on 18 S r DNA sequences was developed and used to detect and enumerate A. anophagefferens. A linear regression（R2 = 0.91） was generated based on cycle thresholds value（Ct） versus known concentrations of A. anophagefferens. Twenty-two field samples collected in coastal waters of Qinhuangdao were subjected to DNA extraction and then analyzed using q PCR. Results showed that A. anophagefferens had a wide distribution in coastal waters along Qinhuangdao. Elevated A. anophagefferens abundance, category 3 brown tide blooms（〉200 000 cells/m L） occurred at Dongshan Beach and Tiger-stone Beach in August in 2013. In shellfish mariculture areas along coastal waters of Qinhuangdao, 4 stations had category 3 blooms, and 6 stations had category 2 blooms（35 000–200 000 cells/m L） in August and all stations had category 1 blooms（〉0 to ≤35 000 cells/m L） in October. Quantitative PCR allows for detection of A. anophagefferens cells at low levels in filed samples, which is essential to effective management and prediction of brown tide blooms.

关键词： Aureococcus anophagefferens quantitative polymerase chain reaction(q PCR) field samples

Performance Analysis of an Organic Rankine Cycle with a Preheated Ejector

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Fluid Dynamics & Materials Processing 2022年第4期18卷 1183-1193页

作者： Kaiyong Hu Yumeng zhang Tianrun zhang Dequan zhang Zhaoxian Yang Tianjin Key Lab of Refrigeration Technology Tianjin University of CommerceTianjin300134China Institute of Food Science and Technology Chinese Academy of Agricultural SciencesNational Risk Assessment Laboratory of Agro-Products Processing Quality and SafetyMinistry of Agriculture and Rural AffairsBeijing100193China Tianjin Tengsheng Technology Co. Ltd.Tianjin300380China

The so-called organic Rankine cycle(ORC)is an effective technology allowing heat recovery from lower temperature *** the present study,to improve its thermal efficiency,a preheated ejector using exhaust steam coming from the expander is integrated in the cycle(EPORC).Considering net power output,pump power,and thermal efficiency,the proposed system is compared with the basic *** influence of the ejector ratio(ER)of the preheated ejector on the system performances is also *** show that the net power output of the EPORC is higher than that of the basic ORC due to the decreasing pump *** given working conditions,the average thermal efficiency of EPORC is 29%higher than that of *** ER has a great impact on the performance of EPORC by adjusting the working fluid fed to the pump,leading to significant variations of the pump work Moreover,the ER has a remarkable effect on the working fluid temperature lift(TL)at the evaporator inlet,thus reducing the evaporator heat *** to the results,the thermal efficiency of EPORC increases by 30%,when the ER increases from 0.05 to 0.4.

关键词： Ejector preheat organic Rankine cycle(EPORC) heat recovery ejector power output