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Prediction of characteristic blast-induced vibration frequency during underground excavation by using wavelet transform

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Frontiers of structural and civil engineering 2022年第8期16卷 1029-1039页

作者： Tae un PAK Guk Rae JO un chol HAN Faculty of Mining engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea school of science and engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea

Blast-induced vibration produces a very complex signal,and it is very important to work out environmental problems induced by *** this study,blasting vibration signals were measured during underground excavation in carbonaceous shale by using vibration pickup cB-30 and FFT analyzer ***,wavelet analysis on the measured results was carried out to identify frequency bands reflecting changes of blasting vibration parameters such as vibration velocity and energy in different frequency *** characteristics are then discussed in view of blast source distance and charge weight per *** analysis of results,it can be found that peak velocity and energy of blasting vibration in frequency band of 62.5–125 Hz were larger than ones in other bands,indicating the similarity to characteristics in the distribution band(31–130 Hz)of main vibration *** frequency bands were affected by blasting source distance,and the frequency band of 0–62.5 Hz reflected the change of charge weight per *** presenting a simplified method to predict main vibration frequency,this research may provide significant reference for future blasting engineering.

关键词： wavelet analysis blast-induced vibration frequency characteristics underground excavation

Wave Radiation by a Floating Body in Water of Finite Depth Using an Exact DtN Boundary condition

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Journal of Ocean university of china 2023年第6期22卷 1497-1504页

作者： RIM un-Ryong Institute of Ocean engineering Kim Chaek University of TechnologyPyongyang 999093Democratic People’s Republic of Korea

The present paper focuses on the wave radiation by an oscillating body with six degrees of freedom by using the DtN artifi-cial boundary *** artificial boundary is usually selected as a circle or spherical surface to solve various types of fields,such as sound waves or electromagnetic waves,provided that the considered domain is infinite or unbounded in all ***,the substantial wave motion is considered in water of finite depth,that is,the fluid domain is bounded vertically but unbounded ***,the DtN boundary condition is given on an artificial cylindrical surface,which divides the water domain into an interior and exterior *** boundary integral equation is adopted to implement the present *** the case of a floating cylinder,the results of hydrodynamic coefficients of a chamfer box are discussed.

关键词： wave radiation boundary element method Dirichlet-to-Neumann map artificial boundary floating body finite-depth water

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

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Neural Regeneration Research 2025年第2期20卷 394-401页

作者： Josep Tomàs Víctor cilleros-Mañé Laia Just-Borràs Marta Balanyà-segura Aleksandra Polishchuk Laura Nadal Marta Tomàs carolina silvera-simón Manel M.santafé Maria A.Lanuza unitat d’Histologia i Neurobiologia(UHNeurob) Facultat de Medicina i Ciències de la SalutUniversitat Rovira i VirgiliReusSpain

During the development of the nervous system,there is an overproduction of neurons and *** competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or *** have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse *** purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this *** particular,we summarize our published results based on transmitter release analysis and axonal c.unts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and c(PKA and PKc)and voltage-gated calcium channels,at different nerve endings in developmental *** dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific *** describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon *** downstream displacement of the PKA/PKc activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary ***,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to red

关键词： acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB

Two-dimensional Dirac plasmon-polaritons in graphene,3D topological insulator and hybrid systems

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Light(science & Applications) 2022年第11期11卷 2602-2616页

作者： chihun In un Jeong Kim Hyunyong choi Department of Physics Freie Universitat BerlinBerlin 14195Germany Department of Physical chemistry Fritz-Haber-lInstitute of the Max-Planck-SocietyBerlin 14195Germany Department of Physics and Astronomy Seoul National UniversitySeoul 08826Republic of Korea Institute of Applied Physics Seoul National UniversitySeoul 08826Republic of Korea Advanced sensor Laboratory Samsung Advanced Institute of TechnologySuwonGyeonggido 16419Republic of Korea

collective oscillations of massless particles in two-dimensional(2D)Dirac materials offer an innovative route toward implementing atomically thin devices based on low-energy quasiparticle *** confinement of nearfield distribution on the 2D surface is es.ential to demonstrate extraordinary optoelectronic functions,providing means to shape the spectral response at the mid-infrared(IR)*** the dynamic polarization from the linear response theory has successfully acc.unted for a range of experimental observations,a unified perspective was stll elusive,connecting the state-of-the-art developments based on the 2D Dirac ***,we review recent works on graphene and three-dimensional(3D)topological insulator(TI)plasmon-polariton,where the mid-IR and terahertz(THz)radiation experiences prominent confinement into a deep-subwavelength scale in a novel optoelectronic *** presenting general light-matter interactions between 2D Dirac plasmon and subwavelength quasiparticle excitations,we introduce various experimental techniques to couple the plasmonpolaritons with electromagnetic *** and optical controls over the plasmonic excitations reveal the hybridized plasmon modes in graphene and 3D Tl,demonstrating an intense near-field interaction of 2D Dirac plasmon within the highly-compressed *** findings can further be applied to invent optoelectronic biomolecular sensors,atomically thin photodetectors,and laser-driven light sources.

关键词： structure Dirac topological

Microstructure and texture optimization by static recrystallization originating from {10-12} extension twins in a Mg-Gd-Y alloy

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Journal of Materials science & Technology 2020年第24期59卷 44-60页

作者： s.H.Lu D.Wu R.s.chen en-hou Han The Group of Magnesium Alloys and Their Applications Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of Materials science and engineering University of Science and Technology of ChinaShenyang 110016China

During the deformation of Mg alloys,{10-12}extension twin often contributes to the formation of basal texture but rarely assists the nucleation of recrystallization,i.e.,effective grain refinement,therefore it seems to make against the improvement of formability and mechanical *** this work,{10-12}extension twin has been creatively utilized as a preference nucleation site for static recrystallization(sRX),achieving grain refinement and orientation randomization in a Mg-Gd-Y alloy using multi-directional impact forging(MDIF)and subsequent annealing *** of{10-12}extension twin on sRX behavior has been investigated by annealing treatment at 450℃using quasi-in-situ optical microscopy(OM)and quasi-in-situ electron back-scattering diffraction(EBsD).The microstructural evolution during annealing shows that several sRX gains can nucleate from the grain boundary of untwinned grains,but they only have few influences on the final microstructure due to their limited volume faction and sluggish *** contrast,a large number of sRX gains can initiate from{10-12}extension twin and grow up without the confine of twin ***,they consume their parent grains and make the main contribution to grain *** should be attributed to those pinned{10-12}twin boundary,by interacting with various dislocation slips during the MDIF process,which can operate like grain boundary,store enough strain energy,and promote the nucleation of sRX during *** the other hand,sRX grains usually keep initial random orientation and further randomize the forging texture during annealing treatment.

关键词： Mg-Gd-Y alloy Multi-directional impact forging(MDIF) {10-12}extension twin Quasi-in-situ electron back-scattering diffraction(EBsD) static recrystallization(sRX)

On the Proper Holomorphic Mappings between Equidimensional Hartogs Domains over Hermitian symmetric Manifolds

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Acta Mathematica sinica,english series 2024年第5期40卷 1215-1228页

作者： en chao BI school of Mathematics and statistics Qingdao UniversityQingdao 266071P.R.China

In this paper,we study a family of Hartogs domains fibred over Hermitian symmetric manifolds being a unit ball in c^(m).The aim of the present study is to establish the rigidity results about proper holomorphic mappings between two equidimensional Hartogs domains over Hermitian symmetric *** particular,we can fully determine its biholomorphic equivalence and automorphism group.

关键词： Proper holomorphic mapping Hartogs domains Hermitian symmetric manifolds

universal enzymatic numerical P systems with small number of enzymatic variables

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science china(Information sciences) 2018年第9期61卷 38-49页

作者： Zhiqiang ZHANG Tingfang WU ANDrei P■un Linqiang PAN Key Laboratory of Image Information Processing and Intelligent control of Education Ministry of china School of Automation Huazhong University of Science and Technology school of Electric and Information engineering Zhengzhou University of Light Industry Bioinformatics Department National Institute of Research and Development for Biological Sciences Department of computer science Faculty of Mathematics and Computer ScienceUniversity of Bucharest

Numerical P systems(for short, NP systems) are distributed and parallel computing models inspired from the structure of living cells and economics. enzymatic numerical P systems(for short, enP systems) are a variant of NP systems, which have been successfully applied in designing and implementing controllers for mobile robots. since enP systems were proved to be Turing universal, there has been much work to simplify the universal systems, where the complexity parameters considered are the number of membranes, the degrees of polynomial production functions or the number of variables used in the *** the number of enzymatic variables, which is es.ential for enP systems to reach universality, has not been investigated. Here we consider the problem of searching for the smallest number of enzymatic variables needed for universal enP systems. We prove that for enP systems as number acceptors working in the all-parallel or one-parallel mode, one enzymatic variable is sufficient to reach universality; while for the one-parallel enP systems as number generators, two enzymatic variables are sufficient to reach *** results improve the best known results that the numbers of enzymatic variables are 13 and 52 for the all-parallel and one-parallel systems, respectively.

关键词： bio-inspired computing numerical P system mobile robot membrane controller universality

computing along the axon

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Progress in Natural science:Materials International 2007年第4期17卷 417-423页

作者： Tseren-Onolt Ishdor Gheorghe Pǎun Research Group on Natural computing Department of CS and AIUniversity of SevillaAvda Reina Mercedes s/n41012 SevillaSpain Institute of Mathematics of the Romanian Academy PO Box 1-764014700 BucharestRomania

A special form of spiking neural P systems, called axon P systems, corresponding to the activity of Ranvier nodes of neuron axon, is considered and a class of sN-like P systems where the computation is done along the ... 详细信息

关键词： membrane computing spiking neural P systems chomsky hierarchy.

Advances in Vehicular Ad-hoc Networks(VANETs):challenges and Road-map for Future Development

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International Journal of Automation and computing 2016年第1期13卷 1-18页

作者： Elias c.Eze si-Jing Zhang en-Jie Liu Joy c.Eze centre for Wireless Research Institute for Research in Applicable Computing (IRAC) Department of Computer Science and TechnologyUniversity of Bedfordshire

Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks （VANETs） over the past few years. A vehicular network consists of vehicle-to-vehicle （V2V） and vehicle-to-infrastructure （V2I） communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system （ITs）. Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITs.

关键词： Vehicle-to-vehicle communication (V2V) vehicle-to-infrastructure (V2I) intelligent transport systems (ITs) IEEE802.11p wireless access in vehicular environment (WAVE) IEEE 1609.