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Isomorphisms of Cubic Cayley Graphs on Dihedral Groups and Sparse Circulant Matrices

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Acta Mathematica Sinica,English Series 2023年第4期39卷 618-632页

作者： istvan kovAcs UP IAM&FAMnIT University of PrimorskaMuzejski trg 26000 KoperSlovenia

We show that,up to isomorphism,there is a unique non-CI connected cubic Cayley graph on the dihedral group of order 2n for each even number n≥*** answers in the negative the question of Li whether all connected cubic Cayley graphs are CI-graphs(Discrete Math.,256,301-334(2002)).As an application,a formula is derived for the number of isomorphism classes of connected cubic Cayley graphs on dihedral groups,which generalises the earlier formula of Huang et *** with the particular case when n is a prime(Acta ***.,***.,33,996-1011(2017)).As another application,a short proof is also given for a result on sparse circulant matrices obtained by Wiedemann and Zieve(arXiv preprint,(2007)).

关键词： Cayley graph graph isomorphism dihedral group circulant matrix

Water in the upper mantle and deep crust of eastern China: concentration, distribution and implications

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national Science Review 2019年第1期6卷 125-144页

作者： Qun-Ke Xia Jia Liu istván kovács Yan-Tao Hao Pei Li Xiao-Zhi Yang Huan Chen Ying-Ming Sheng School of Earth Sciences Zhejiang University CAS Key Laboratory of Crust-Mantle Materials and Environments University of Science and Technology of China Hungarian Geological and Geophysical Institute 4. School of Earth Sciences and Engineering Nanjing University

Understanding the concentration and distribution of water in the Earth’s mantle plays a substantial role in studying its chemical, physical and dynamic processes. After a decade of research, a comprehensive dataset of water content in upper-mantle samples has been built for eastern China, which is now the only place with water-content data from such diverse types of natural samples, and provides an integrated picture of the water content and its distribution in the upper mantle at a continental scale. The main findings include the following:(i) the temporal heterogeneity of the water content in the lithospheric mantle from early Cretaceous(～120 Ma) to Cenozoic(nnected with the stability of the north China Craton(from its destruction to its consolidation);(ii) the heterogeneous water content in the Cenozoic lithospheric mantle beneath different blocks of eastern China was not only inherited from tectonic settings from which they came, but was also affected later by geological processes they experienced;(iii) the distinct water content between the lowermost crust and lithospheric mantle of eastern China and its induced rheological contrast at the base of the crust indicate that the continental crust–mantle boundary could behave either in a coupled or decoupled manner beneath different areas and/or at different stages;(iv) the alkali basalts of eastern China demonstrate a heterogeneous distribution of water content in the mantle;local and regional comparisons of the water content between the lithospheric mantle and basalts’ source indicate that the Cenozoic alkali basalts in eastern China were not sourced from the lithospheric ***, the inferred high water contents in the mantle sources suggest that the Cenozoic eastern China basalts were likely sourced from the mantle transition zone(MTZ); and(v) both oceanic and continental crusts may carry a certain amount of water back into the deep mantle of eastern China by plate *** re

关键词： water upper mantle and deep crust continental stability basalt genesis eastern China

利用被动源地震实验和接收函数分析确定迪纳拉山脉北部和潘诺尼亚盆地西南部交界处地壳结构

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世界地震译丛 2017年第1期48卷 74-96页

作者： Franjo umanovac Endre Hegedüs Jasna Oreskovi Sasa Kolar Attila C.kovcs Darko Dudjak istvn J.kovcs 王林福建省地震局

通过在迪纳拉山脉和潘诺尼亚盆地西南交界带进行被动源地震实验,确定了地壳结构和波速不连续面。实验目的是确定亚得里亚海微板块与作为欧洲板块一部分的潘诺尼亚地块的关系。大部分流动台站沿着Alp07剖面(主动源ALP 2002项目的一部分)... 详细信息

通过在迪纳拉山脉和潘诺尼亚盆地西南交界带进行被动源地震实验,确定了地壳结构和波速不连续面。实验目的是确定亚得里亚海微板块与作为欧洲板块一部分的潘诺尼亚地块的关系。大部分流动台站沿着Alp07剖面(主动源ALP 2002项目的一部分)布设在克罗地亚。该剖面从伊斯特拉半岛到德拉瓦河沿线呈西西南-东东南向延伸约300km。利用P波接收函数方法分析测线上13个临时地震台站的远震记录。Alp07剖面得到了两种特征接收函数(RF),分属于迪纳拉和潘诺尼亚地壳,交界带则包含两种类型。迪纳拉型地壳主要包含三组地壳不连续面:沉积基底、壳内不连续面和莫霍不连续面,而潘诺尼亚类型地壳仅包含两组不连续界面。在潘诺尼亚型地壳中并未观测到壳内不连续面,因此认为潘诺尼亚盆地为单层地壳结构。应用接收函数正演模拟和H-κ叠加两种分析方法开展了地壳结构研究,并将该结果与Alp07剖面主动源折射地震结果进行了比较。接收函数模拟得到了可靠的莫霍面深度结果,与Alp07剖面的地震折射结果相一致,即潘诺尼亚区域地壳特征为简单地壳结构,波速较低(VP在5.9~6.2km/s)。迪纳拉及其周缘,由于地壳结构更为复杂,接收函数模拟得到莫霍面深度较Alp07剖面更大,高达15%。受短周期台站数据频带限制,利用H-κ叠加方法计算得到的莫霍面深度在较大范围内(±13km)变化。通过与先前所有结果进行对比,排除了差异较大的5个台站的结果,而与Alp07剖面附近的莫霍不连续面相比,其他7个台站莫霍面深度差异在15%内变化。

关键词：大陆地壳组成地震活动性和地质构造体波地壳结构欧洲

Metasomatism-induced wehrlite formation in the upper mantle beneath the nógrád-G?m?r Volcanic Field(northern Pannonian Basin):Evidence from xenoliths

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Geoscience Frontiers 2020年第3期11卷 943-964页

作者： Levente Patko nora Liptai Laszlo Elod Aradi Rita Klebesz Eszter Sendula Robert J.Bodnar istvan Janos kovacs Karoly Hidas Bernardo Cesare Attila novak Balazs Trasy csaba Szabo Lithosphere Fluid Research Lab Institute of Geography and Earth SciencesEotvos Lor and UniversityBudapestHungary Isotope Climatology and Environmental Research Centre Institute for Nuclear ResearchHungarian Academy of SciencesDebrecenHungary CCFS-GEMOC Department of Earth and Planetary SciencesMacquarie UniversitySydneyAustralia Geodetic and Geophysical Institute Research Centre for Astronomy and Earth SciencesHungarian Academy of SciencesSopronHungary Fluids Research Laboratory Department of GeosciencesVirginia TechBlacksburgVAUnited States MTA csFK Lendület Pannon LitH2Oscope Research Group Geodetic and Geophysical InstituteResearch Centre for Astronomy and Earth SciencesHungarian Academy of SciencesSopronHungary Instituto Andaluz de Ciencias de La Tierra CSIC&UGRArmillaGranadaSpain Department of Geosciences University of PaduaPaduaItaly Department of Geology Eotvos Lorand UniversityBudapestHungary

Clinopyroxene-enriched upper mantle xenoliths classified as wehrlites are common(~20% of all xenoliths) in the central part of the nograd-G(o| ")m(o|")r Volcanic Field(nGVF),situated in the northern margin of the Pannonian Basin in northern Hungary and southern *** this study,we thoroughly investigated 12 wehrlite xenoliths,two from each wehrlite-bearing occurrence,to determine the conditions of their *** textural features,including clinopyroxene-rich patches in an olivine-rich lithology,orthopyroxene remnants in the cores of newlyformed clinopyroxenes and vermicular spinel forms all suggest that wehrlites were formed as a result of intensive interaction between a metasomatic agent and the peridotite wall *** on the major and trace element geochemistry of the rock-forming minerals,significant enrichment in basaltic(Fe,Mn,Ti) and high field strength elements(nb,Ta,Hf,Zr) was observed,compared to compositions of common lherzolite *** presence of orthopyroxene remnants and geochemical trends in rock-forming minerals suggest that the metasomatic process ceased before complete wehrlitization was *** composition of the metasomatic agent is interpreted to be a mafic silicate melt,which was further confirmed by numerical modelling of trace elements using the plate *** model results also show that the melt/rock ratio played a key role in the degree of petrographic and geochemical *** lack of equilibrium and the conclusions drawn by using variable lherzolitic precursors in the model both suggest that wehrlitization was the last event that occurred shortly before xenolith entrainment in the host mafic *** suggest that the wehrlitization and the Plio-Pleistocene basaltic volcanism are related to the same magmatic event.

关键词： Wehrlite xenoliths Upper mantle metasomatism Mafic silicate melt Trace element modelling

Mucosal healing effect of mesalazine granules in naproxen-induced small bowel enteropathy

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World Journal of Gastroenterology 2013年第6期19卷 889-896页

作者： istván Rácz Milán Szalai Valéria kovács Henriett Regczi Gyngyi Kiss Zoltán Horváth Department of Gastroenterology Petz Aladár County and Teaching Hospital Department of Mathematics and Computational Sciences Széchenyi István University

AIM:To investigate the effect of mesalazine granules on small intestinal injury induced by naproxen using capsule endoscopy (CE).METHODS:This was a single center,non-randomized,open-label,uncontrolled pilot study,using the PillCam SB CE system with RAPID 5 *** Lewis Index Score (LIS) for small bowel injury was investigated to evaluate the severity of mucosal *** patients with at least one month history of daily naproxen use of 1000 mg and proton pump inhibitor co-therapy were *** with a minimum LIS of 135 were eligible to enter the 4-wk treatment phase of the *** this treatment period,3 × 1000 mg/d mesalazine granules were added to ongoing therapies of 1000 mg/d naproxen and 20 mg/d *** the end of the 4-wk combined treatment period,a second small bowel CE was performed to re-evaluate the enteropathy according to the LIS *** primary objective of this study was to assess the mucosal changes after 4 wk of mesalazine ***:A total of 18 patients (16 females),ranging in age from 46 to 78 years (mean age 60.3 years) were screened,all had been taking 1000 mg/d naproxen for at least one *** patients were excluded from the mesalazine therapeutic phase of the study for the following reasons:the screening CE showed normal small bowel mucosa or only insignificant damages (LIS n five patients,the screening esophagogastroduodenoscopy revealed gastric ulcer in one patient,capsule technical failure and incomplete CE due to poor small bowel cleanliness in two *** patients (9 female,mean age 56.2 years) whose initial LIS reached mild and moderate-to-severe enteropathy grades (between 135 and 790 and ≥ 790) entered the 4-wk therapeutic phase and a repeat CE was *** comparing the change in LIS from baseline to end of treatment in all patients,a marked decrease was seen (mean LIS:1236.4 ± 821.9 vs 925.2 ± 543.4,P=0.271).Moreover,a significant difference between pre-and post-t

关键词： nonsteroidal anti-inflammatory drug Small bowel enteropathy Mesalazine granules Mucosal healing Capsule endoscopy

Harmonics in the Squirrel Cage Induction Motor Analytic Calculation Part III: Influence on the Torque-speed Characteristic

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 86-102页

作者： G.kovács the Ganz Electric Works BudapestHungary

The harmonics that appear in the squirrel cage asynchronous machine have been discussed in great detail in the literature for a long time. However, the systematization of the phenomenon is still pending, so we made an attempt to fill this gap in the previous parts of our study by elaborating formulas for calculation of parasitic torques. It was a general demand among those who work in this field towards the author to verify his formulas with measurements. In the literature, it seems,only one detailed, purposeful series of measurements has been published so far, the purpose of which was to investigate the effect of the number of rotor slots on the torque-speed characteristic curve of the machine. The main goal of this study is to verify the correctness of the formulas by comparing them with the referred series of measurements. Relying on this, the expected synchronous parasitic torques were developed for the frequently used rotor slot numbers-as a design guide for the ***, together with our complete table for radial magnetic pull published in our previous work, the designer has all the principles, data and formulas available for the right number of rotor slots for his given machine and for the drive system. This brings this series of papers to an end.

关键词： Asynchronous parasitic torques Induction motor Squirrel cage rotor Space harmonics Synchronous parasitic torques

Harmonics in the Squirrel Cage Induction Motor Analytic Calculation-Part Ⅰ: Differential Leakage, Attenuation, Asynchronous Parasitic Torques

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CES Transactions on Electrical Machines and Systems 2023年第4期7卷 320-329页

作者： G.kovács Ganz Electric Works 1095 BudapestHungary

The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the related differential leakage, attenuation, asynchronous parasitic torques have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time-in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. An existing, commonly used, but still impractical basic figure has been modified to more clearly demonstrate the response of the rotor for the harmonics of the stator. The need to treat differential leakage, asynchronous parasitic torques and attenuation together will be demonstrated: new formula for asynchronous parasitic torque is derived;the long-used characteristic curves for differential leakage and attenuation used separately so far was merged into one, correct curve in order to provide a correct design guide for the engineers.

关键词： Asynchronous parasitic torque Attenuation Differential leakage Squirrel cage induction motor Winding harmonics

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Technological Aspects of Refuse Fats, Pretreatment and Retrofitting

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Journal of Environmental Science and Engineering(B) 2021年第2期10卷 41-54页

作者： kovács JAndrás Hodován istván Ferrari Ben KUKK K+F Ltd. Budapest 1083Hungary ATEV Zrt Budapest 1097Hungary QS Biodiesel Ltd. London W1J 8DJUK

Scope of the article is to discuss pretreatment of refuse,nonedible animal fats into biodiesel feedstock to improve yields of standard quality biofuel at low operational *** are equally viable for 2nd generation biodiesel processing technologies and to extend catalysts *** fats are vulnerability to storage conditions having significant influence on loss of market *** concerns expressed in terms of high levels of FFA(Free Fatty Acid),moisture,impurities have been *** constituents are present in these feedstocks in complicated,stubborn colloid chemical structures with direct impacts on *** edible grade oil techniques have been revisited but failed to produce high market-value biodiesel feedstock at acceptable levels of yield and *** refinery techniques,selective solvent refining and vacuum distillation have also not met *** and direct esterification conversion techniques were efficient in reduction of FFA and impurities to acceptably low level at reasonable *** catalyzed direct esterification proved to be lower cost technique to produce good quality biodiesel feedstock that can be processed in first generation alkali-based transesterification and hydrotreatment techniques ***-Sol apolar solvent born technology has been shown to be the best performing option in *** esterification was demonstrated in a truly continuous,counter current,solvent born mode with substantial energy and resource efficiency gains.

关键词： Waste to fuel renewable energy biodiesel resource efficiency

Efficiency of local minima and GLM techniques in sinkhole extraction from a LiDAR-based terrain model

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International Journal of Digital Earth 2019年第9期12卷 1067-1082页

作者： Péter Enyedi Melinda Pap Zoltán kovács László Takács-Szilágyi Szilárd Szabó a Department of Physical Geography and Geoinformatics University of DebrecenDebrecenHungary Internet of Things Research Institute Eszterházy Károly University of Applied SciencesEgerHungary

The aim of this paper was to study reliable automated delineationpossibilities of karst sinkholes using a LiDAR-based digital terrain model(DTM) with pixel-based classifications. We applied two approaches toextract sinkholes: (1) general linear modeling (GLM) with morphometricindices derived from DTM;(2) and a local minima-based delineationusing only LiDAR DTM as the input layer. The outcome of the localminima was significantly different from the reference ones but found allthe sinkholes without previous knowledge of the area. The GLM-basedoutcome did not differ statistically from the reference. Results showedthat these approaches were efficient in detecting sinkholes based onLIDAR derivatives, and can be used for risk assessment and hazardpreparedness in karst areas: GLM had an overall accuracy of 89.5% andlocal minima had an accuracy of 92.3%;both methods identifiedsinkholes but also had commission errors, identifying depressions assinkholes.

关键词： Karst mapping sinkhole identification general linear model statistical evaluation sink fill