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On the Cauchy problem and peakons of a two-component Novikov system

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Science China Mathematics 2020年第10期63卷 1965-1996页

作者： Changzheng qu Ying Fu School of Mathematics and Statistics Ningbo UniversityNingbo 315211China School of Mathematics Northwest UniversityXi’an 710127China

We study a two-component Novikov system,which is integrable and can be viewed as a twocomponent generalization of the Novikov equation with cubic *** primary goal of this paper is to understand how multi-component equations,nonlinear dispersive terms and other nonlinear terms affect the dispersive dynamics and the structure of the peaked *** establish the local well-posedness of the Cauchy problem in Besov spaces B^s/p,r with 1 p,r+∞,s>max{1+1/p,3/2}and Sobolev spaces H^s(R)with s>3/2,and the method is based on the estimates for transport equations and new invariant properties of the ***,the blow-up and wave-breaking phenomena of solutions to the Cauchy problem are studied.A blow-up criterion on solutions of the Cauchy problem is *** addition,we show that this system admits single-peaked solitons and multi-peaked solitons on the whole line,and the single-peaked solitons on the circle,which are the weak solutions in both senses of the usual weak form and the weak Lax-pair form of the system.

关键词： two-component Novikov system Hamiltonian structure Camassa-Holm type equation wellposedness peaked soliton

Distribution Patterns of Calcite Cement in the Turbidite Sandstones of the Shahejie Formation in the Dongying Depression,Eastern China

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Acta Geologica Sinica(English Edition) 2022年第3期96卷 1041-1056页

作者： ZHANG Yongwang qu Zhengyang State Key Laboratory of Petroleum Resources and Prospecting Beijing 102249China College of Geosciences China University of Petroleum-BeijingBeijing 102249China No.4 Oil Production Plant PetroChina Changqing Oilfield CompanyYinchuan 718500China

Calcite cements are volumetrically dominant among the most diagenetic constituents in turbidite sandstones of the Paleogene Shahejie Formation in the Dongying *** results show carbonate cements mainly occur in three phases:Calcite I(pre-compaction),Calcite II(post-compaction)and ankerite in the turbidite *** isotopic composition of Calcite I and Calcite II range from−4.3‰to 4.4‰,−3.5‰to 4.3‰PDB,respectively,suggesting that the calcite cements are mainly derived from the interbedded *** early calcite cement precipitated from the mixing of lacustrine and meteoric waters at 38-69℃.The late-phase calcite precipitated from pore waters modified by water-rock interactions at 64-126℃.Two distribution patterns of calcite cements can be identified,depending on their position within the *** peripheral cementation of the sandstones is near the sand-shale *** development of cement is controlled by sandstone thickness and the properties of the interbedded *** scattered cementation,the distribution of the calcite cement is not controlled by the sand-shale *** cement was preferentially distributed in coarse-grained sandstones,indicating that sandstones with high original permeability are the preferred pathway for the migration of early diagenetic fluids.

关键词： turbidite sandstone calcite cement distribution patterns Dongying Depression

Impedance spectroscopy for quantum dot light-emitting diodes

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Journal of Semiconductors 2023年第9期44卷 26-38页

作者： Xiangwei qu Xiaowei Sun Institute of Nanoscience and Applications and Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen 518055China Key Laboratory of Energy Conversion and Storage Technologies(Southern University of Science and Technology) Ministry of Educationand Shenzhen Key Laboratory for Advanced Quantum Dot Displays and LightingSouthern University of Science and TechnologyShenzhen 518055China

Impedance spectroscopy has been increasingly employed in quantum dot light-emitting diodes(QLEDs)to investigate the charge dynamics and device *** this review,we introduce the mathematical basics of impedance spectroscopy that applied to *** particular,we focus on the Nyquist plot,Mott-Schottky analysis,capacitance-frequency and capacitance-voltage characteristics,and the d C/d V measurement of the *** impedance measurements can provide critical information on electrical parameters such as equivalent circuit models,characteristic time constants,charge injection and recombination points,and trap distribution of the ***,this paper will also discuss the disadvantages and limitations of these ***,this review provides a deeper understanding of the device physics of QLEDs through the application of impedance spectroscopy,offering valuable insights into the analysis of performance loss and degradation mechanisms of QLEDs.

关键词： quantum dot light-emitting diode impedance spectroscopy equivalent circuit model charge dynamics

Advances in tissue state recognition in spinal surgery:a review

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Frontiers of Medicine 2021年第4期15卷 575-584页

作者： Hao qu Yu Zhao Department of Orthopaedics Peking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China

Spinal disease is an important cause of cervical discomfort,low back pain,radiating pain in the limbs,and neurogenic intermittent claudication,and its incidence is increasing *** the etiological viewpoint,these symptoms are directly caused by the compression of the spinal cord,nerve roots,and blood vessels and are most effectively treated with *** surgeries are primarily performed using two different techniques:spinal canal decompression and internal *** the past,tactile sensation was the primary method used by surgeons to understand the state of the tissue within the operating ***,this method has several disadvantages because of its ***,it has become the focus of spinal surgery research so as to strengthen the objectivity of tissue state recognition,improve the accuracy of safe area location,and avoid surgical injury to *** from traditional imaging methods,surgical sensing techniques based on force,bioelectrical impedance,and other methods have been gradually developed and tested in the clinical *** article reviews the progress of different tissue state recognition methods in spinal surgery and summarizes their advantages and disadvantages.

关键词： spinal surgery tissue state recognition image force sensing bioelectrical impedance

Recent advancement of chemical imaging in pharmaceutical quality control:From final product testing to industrial utilization

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Journal of Innovative Optical Health Sciences 2020年第1期3卷 19-34页

作者： Luming Liu Haibin qu College of Pharmaceutical Sciences Zhejiang University HangzhouZhejiang 310058P.R.China

Chemical imaging(CI)possesses a strong ability of pharmaceutical *** great strength relies on the integration of traditional spectroscopy(one dimension)and imaging technique(two dimensions)to generate three-dimensional data *** pre-processing or processing methods are proposed to analyze vast data matrixes and thereby realizing different research *** this review paper,various pharmaceutical applications of quality control over the past few years are summed up in two groups of final product test and industrial *** scope of"quality control"here includes traditional analytical use,process understanding and manufactural ***,two major challenges about undesirable sample geometry and lengthy acquisition time are discussed for prospective commercial or industrial application.

关键词： Hyperspectral imaging pharmaceutical application multivariate data analysis quality control

Invariant hypersurface flows in centro-affine geometry

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Science China Mathematics 2021年第8期64卷 1715-1734页

作者： Yun Yang Changzheng qu Department of Mathematics Northeastern UniversityShenyang 110819China School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

In this paper,the invariant geometric flows for hypersurfaces in centro-affine geometry are *** first present evolution equations of the centro-affine invariants corresponding to the geometric *** on these fundamental evolution equations,we show that the centro-affine heat flow for hypersurfaces is equivalent to a system of ordinary differential equations,which can be solved ***,the centro-affine invariant normal flows for hypersurfaces are investigated,and two specific flows are provided to illustrate the behaviour of the flows.

关键词： invariant geometric flow centro-affine geometry heat flow normal flow centro-affine invariant

Analysis of Seasonal Differences of Chlorophyll,Dimethylsulfide,and Ice Between the Greenland Sea and the Barents Sea

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Journal of Ocean University of China 2023年第6期22卷 1592-1604页

作者： ZHONG Guangsheng qu Bo School of Science Nantong University226019China

Arctic Ocean(AO)climate is closely related to sea ice concentration(ICE)and chlorophyll_a(CHL)*** 2003–2014,the spatial average concentrations of CHL,ICE,sea surface temperature(SST),wind speed(WIND)in the Greenland Sea region(GS)(20˚W–10˚E,70˚–80˚N)and the Barents Sea region(BS)(30˚–50˚E,70˚–80˚N)are analysed and *** CHL was observed in BS,about 60%higher than that in *** with the northern regions of BS and GS(BSN and GSN),CHL in the southern region of BS and GS(BSS and GSS)increased by 77%and 42%*** ice melting in BSN is the main reason for phytoplankton *** 2010,there was an unusual peak of CHL concentration in *** sea-sonal peaks of CHL appeared two weeks earlier in BS than in *** earlier and more extensive ice melting and the persistent nega-tive North Atlantic Oscillation(NAO)index may be the reasons for higher CHL blooms in *** spatial average ICE concentra-tion of BS in BSN and BSS is 27%and 1.2%*** NAO in the previous winter may lead to an increase in ICE in *** has a great influence on CHL and ICE in *** melting is positively correlated with CHL,especially in GS in recent decades,CHL has a significant positive correlation with surface mass concentration of dimethylsulfide(DMS),especially in *** an indicator of Arctic warming,BS needs more attention from Arctic researchers.

关键词： dimethylsulfide chlorophyll ice North Atlantic Oscillation Arctic

Vertical Chlorophyll and Dimethylsulfide Profile Simulations in Southern Greenland Sea

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Journal of Ocean University of China 2022年第6期21卷 1565-1574页

作者： qu Bo SUN Wenjing School of Science Nantong UniversityNantong 226007China YK Pao School Middle School CampusShanghai 200336China

Biogenetic sulfide dimethylsulfide(DMS)plays a major role on the global climate,especially in Arctic *** simulate DMS concentration is an important *** we introduced both biogeochemical depth-averaged model G93 and its extension model-one dimensional DMS *** surface concentrations,vertical profiles of chlorophyll(CHL)and DMS are simulated using the two models within southern Greenland Sea(0°E–10°E,70°N–75°N)during year *** the input data for the models simulations,the spatial monthly mean of methodology forcings including sea surface temperature(SST),wind speed(WIND),cloud cover(CLD),sea ice concentration(ICE)and mixed layer depth(MLD)are *** 8-day time series of chlorophyll-a(CHL)are used as observation data for CHL related parameter ***ó’s imperial formula is used as the monthly DMS observation *** Genetic Algorithm technique is used for the parameter *** simulation results show that the most DMS related surface concentrations exhibit the normal distributions with peak during ***,DMS and DMSP(dimethylsulphoniopropionate)vertical profiles are obtained for July,August and September in year *** had the higher variation of subsurface concentration maximum(SCM)in July with the lower surface concentration *** had surface higher and subsurface lower profile for the all three *** also had subsurface high in *** SCM CHL diurnal variation in the subsurface also can be resulted from diurnal changes in MLD and vertical mixing variations,plus photolysis and wind-driven ventilations.

关键词： dimethylsulfide vertical profile chlorophyll biogeochemical modeling Greenland Sea

Finite p-groups whose nonnormal subgroups are metacyclic

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Science China Mathematics 2020年第7期63卷 1271-1284页

作者： Qiangwei Song Haipeng qu Department of Mathematics Shanxi Normal UniversityLinfen 041004China

For an odd prime p,we give a criterion for finite p-groups whose nonnormal subgroups are metacyclic,and based on the criterion,the p-groups whose nonnormal subgroups are metacyclic are classified up to *** solves a pr... 详细信息

关键词： metacyclic groups minimal nonabelian groups minimal nonmetacyclic groups p-groups of maximal class the rank of a p-group