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Geodesy and Geodynamics 2020年第1期11卷 56-63页

作者： n.V.Silacheva u.K.Kulbayeva n.A.Kravchenko Institute of Seismology AlmatyKazakhstan

Seismic microzonation for Almaty city for the first time use probabilistic approach and hazard is expressed in terms of not only macroseismic intensity,but also Peak Ground Acceleration(PGA).To account for the effects of local soil conditions,the continual approach proposed by ***[1,2]was used,in which soil coefficients are a function of the continuously changing seismic *** coefficients were calculated using the new data of geological and geophysical surveys and findings of previous geotechnical *** used approach made it possible to avoid using soil categories and a jump change in characteristics of soil conditions and seismic *** developed seismic microzonation maps are prepared for further introduction into the normative documents of the Republic of Kazakhstan.

关键词： Seismic microzonation maps Peak ground acceleration Soil conditions Seismic rigidity Continual theory

Q-Switched Raman Fiber Laser with Molybdenum Disulfide-Based Passive Saturable Absorber

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Chinese Physics Letters 2016年第7期33卷 98-101页

作者： n.Hisamuddin.u.n.Zakaria M.Z.Zulkifli A.A.Latiff H.Ahmad S.W.Harun Photonics Research Center University of Malaya Department of Electrical Engineering Faculty of EngineeringUniversity of Malaya Aston Institute of Photonics Technologies Aston University

We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide （MoS2） as a saturable absorber （SA）. The SA is assembled by depositing a mechanically exfoliated MoS2 onto a fiber ferrule facet before it is matched with another clean ferrule via a connector. It is inserted in a Raman fiber laser cavity with a total cavity length of about 8kin to generate a Q-switching pulse train operating at 1560.2nm. A 7.7-kin-long dispersion compensating fiber with 584 ***-i km-1 of dispersion is used as a nonlinear gain medium. As the pump power is increased from 395 m W to 422 m W, the repetition rate of the Q-switching pulses can be increased from 132.7 to 137.4 kHz while the pulse width is con.u.rently decreased from 3.35μs to 3.03μs. The maximum pulse energy of 54.3 nJ is obtained at the maximum pump power of 422 roW. These results show that the mechanically exfoliated MoS2 SA has a great potential to be used for pulse generation in Raman fiber laser systems.

关键词： of with SA Q-Switched Raman Fiber Laser with Molybdenum Disulfide-Based Passive Saturable Absorber is in for been that

Synthesis of crystalline perovskite-structured SrTiO_3 nanoparticles using an alkali hydrothermal process

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International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 109-115页

作者： u.K.n.Din T.H.T.Aziz M.M.Salleh A.A.umar Institute of Microengineering and nanoelectronics (IMEn) Universiti Kebangsaan Malaysia

We report an experimental route for synthesizing perovskite-structured strontium titanate （SrTiO3） nanocubes using an alkali hydrothermal process at low temperatures without further heating. Furthermore, we studied the influence of heating time （at 180℃） on the crystallinity, morphology, and perovskite phase formation of SrTiO3. The SrTiO3 powder, which is formed via nanocube agglomeration, transforms into cubic particles with a particle size of 120--150 nm after 6 h of hydrothermal sintering. The crystallinity and percentage of the perovskite phase in the product increased with heating time. The cubic particles contained 31.24at% anatase TiO2 that originated fi＇om the precursor. By varying the weight ratio of anatase TiO2 used to react with the strontium salt precursor, we reduced the anatase-TiO2 content to 18.8at%. However, the average particle size increased when the anatase-TiO2 content decreased.

关键词： strontium titanate nanoparticles anatase hydrothermal synthesis

Trace-Rare-Gas Optical Emission Spectroscopy of nitrogen Plasma Generated at a Frequency of 13.56 MHz

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Plasma Science and Technology 2011年第2期13卷 208-212页

作者： n.u.REHMAn F.u.KHAn S.nASEER G.MuRTAZA S.S.HuSSAIn I.AHMAD M.ZAKAuLLAH Department of Physics COMSATS Institute of Information Technology Department of Physics Gomal University Department of Physics Peshawar University Department of Physics Quaid-i-Azam University

Optical emission spectroscopic measurement of trace rare gas is carried out to determine the density of nitrogen （n） atom, in a nitrogen plasma, as a function of filling pressure and RF power applied. 2% of argon, used as an actinometer, is mixed with nitrogen. In order to normalize the changes in the excitation cross section and electron energy distribution function at different operational conditions, the Ar-I emission line at 419.83 nm is used, which is of nearly the same excitation efficiency coefficient as that of the nitrogen emission line at 493.51 nm. It is observed that the emission intensity of the selected argon and atomic nitrogen lines increases with both pressure and RF power, as does the nitrogen atomic density.

关键词： optical actinometry n atomic density EEDF RF plasma

Structural and photoluminescence studies on europium-doped lithium tetraborate(Eu:Li2B4O7)single crystal grown by microtube Czochralski(μT-Cz)technique

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Chinese Physics B 2016年第5期25卷 429-433页

作者： A Kumaresh R Arun Kumar n Ravikumar u Madhusoodanan B S Panigrahi K Marimuthu M Anuradha GRD Centre for Materials Research PSG College of TechnologyCoimbatoreIndia Department of Physics PSG College of TechnologyCoimbatoreIndia Radiation Safety Division Indira Gandhi Centre for Atomic ResearchKalpakkamIndia Department of Physics Gandhigram Rural UniversityDindigulIndia PSG Institute of Advanced Studies CoimbatoreIndia

Rare earth europium（Eu（3＋））-doped lithium tetraborate（Eu：Li_2B_4O_7） crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique（μT-Cz） for the first time. The grown crystals are subjected to powder x-ray diffraction（PXRD） analysis which reveals the tetragonal crystal structure of the crystals. uV–vis–nIR spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of BO_3 and BO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared（FTIR） spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate（LTB） single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission *** chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931（Commission International d＇Eclairage） color chromaticity diagram.

关键词： crystal growth optical material growth from melt photoluminescence study

Indentation Size Effect and Microhardness Study of β-Sn Single Crystals

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Chinese Physics Letters 2005年第12期22卷 3137-3140页

作者： O. SAHIn O. uZun.u. KOLEMEn B. DuZGun n. uCAR Department of Physics Art and Science Faculty Suleyman Demirel University Isparta Turkey Department of Physics Art and Science Faculty Gaziosmanpasa University Tokat Turkey Department of Physics K. K. Education Faculty Ataturk-University Erzurum Turkey

The load dependence of apparent microhardness of β-Sn single crystals having different growth directions is investigated. The measurements are performed on （110） planes of these crystals in the load range from 10 to 50 mn. It is found that the degree of the microhardness anisotropy decreases for higher indentation test loads. The examined materials exhibit the behaviour of indentation size effect （ISE）, i.e., the apparent hardness increases with decreasing indentation load. neither Meyer＇s law nor the proportional specimen resistance （PSR） model can fully explain the nonlinear variation of microhardness with load. Instead, preference is given to modified the PSR model based on the consideration of the effect of machining-in.u.ed residually stressed surface on the hardness measurement.

关键词： COBALT-BASED ALLOYS SILICOn-nITRIDE STRuCTuRAL-PROPERTIES KnOOPMICROHARDnESS BASAL-PLAnE HARDnESS CERAMICS AnISOTROPY PRESSuRE SOLIDS

Bistability in Coupled Oscillators Exhibiting Synchronized Dynamics

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Communications in Theoretical Physics 2010年第5期53卷 815-824页

作者： O.I.Olusola u.E.Vincent A.n.njah J.A.Olowofela Department of Physics University of Agriculture Department of Physics Lancaster University Institut fur Theoretische Physik Technische Universitt Clausthal Department of Physics Olabisi Onabanjo University

We report some new results associated with the synchronization behavior of two coupled double-well Duffing oscillators （DDOs）. Some sufficient algebraic criteria for global chaos synchronization of the drive and response DDOs via linear state error feedback control are obtained by means of Lyapunov stability theory. The synchronization is achieved through a bistable state in which a periodic attractor co-exists with a chaotic attractor. using the linear perturbation analysis, the prevalence of attractors in parameter space and the associated bifurcations are examined. Subcritical and supercritical Hopf bifurcations and abundance of Arnold ton.u.s -- a signature of mode locking phenomenon are found.

关键词： chaos synchronization Duffing oscillator bistability Lyapunov stability theory

Superstatistics of Modified Rosen-Morse Potential with Dirac Delta and uniform Distributions

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Communications in Theoretical Physics 2019年第10期71卷 1246-1252页

作者： u.S.Okorie A.n.Ikot G.J.Rampho R.Sever Department of Physics AkwaIbom State UniversityIkotAkpadenUyo.Nigeria Department of Physics University of Port HarcourtChobaNigeria Department of Physics University of South AfricaFlorida Park1710South Africa Department of Physics Middle East Technical University06800AnkaraTurkey

We discuss the thermodynamic properties of a modified Rosen-Morse potential using the q-deformed superstatistics approaches. We obtain the partition function with the help of the generalized Boltzmann factor from the modified Dirac delta distribution and uniform distribution. Other thermodynamic function is obtained for the superstatistics of the two distributions considered. We also discuss our results graphically and obtain the ordinary statistical quantities when the deformation parameter tends to zero.

关键词： superstatistics partition function thermodynamic function

Meshless Method with Domain Decomposition for Submerged Porous Breakwaters in Waves

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Journal of Ocean.u.iversity of China 2021年第6期20卷 1325-1340页

作者： CHIOuKH nadji YÜKSEL Yalçın Department of Hydraulics University of Sidi Bel-AbbesSidi Bel-Abbes 22000Algeria Laboratory of Civil Engineering and Environment University of Sidi Bel-AbbesSidi Bel-Abbes 22000Algeria Laboratory of Hydraulics and Coastal Engineering Yildiz Technical UniversityEsenler-Istanbul 34220Turkey

Based on the improved version of the meshless sin.u.ar boundary method(ISBM)in multi domain(MD),a numerical method is proposed in this paper to study the interaction of submerged permeable breakwaters and regular waves at normal *** account for fluid flow inside the porous breakwaters,the conventional model of Sollitt and Cross for porous media is *** single and dual trapezoidal breakwaters are *** physical problem is formulated in the context of the linear potential wave *** domain decomposition method(DDM)is employed,in which the full computational domain is decomposed into separate domains,that is,the fluid domain and the domains of the ***,appropriate mixed type boundary and continuity conditions are applied for each subdomain and at the interfaces between *** solution is approximated in each subdomain by the *** discretized algebraic equations are combined,resulting in an overdetermined full system that is solved using a least-square solution *** numerical results are presented in terms of the hydrodynamic quantities of reflection,transmission,and wave-energy *** relevance of the results of the present numerical procedure is first validated against data of previous studies,and then selected computations are discussed for various structural *** proposed method is demonstrated to be highly accurate and computationally efficient.

关键词： meshless method domain decomposition regular waves breakwaters porosity reflection transmission dissipation coastal environment

Probabilistic seismic hazard assessment of Kazakhstan and Almaty city in peak ground accelerations

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Geodesy and Geodynamics 2018年第2期9卷 131-141页

作者： n.V.Silacheva u.K.Kulbayeva n.A.Kravchenko Institute of Seismology National Center for Seismological Observations and Research

As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment) procedure to the large amount of available geological, geophysical and tectonic Kazakh data and to meet standard requirements for the Eurocode 8. The new procedure has been.u.ed within national projects to develop the Probabilistic GSZ(General Seismic Zoning) maps of the Kazakhstan territory and the SMZ(Probabilistic Seismic Microzoning) maps of Almaty city. They agree with the seismic design principles of Eurocode 8 and are expressed in terms of not only seismic intensity,but also engineering parameters(peak ground acceleration PGA). The whole packet of maps has been developed by the Institute of Seismology, together with other Kazakhstan Institutions. Our group was responsible for making analysis in PGA. The GSZ maps and hazard assessment maps for SMZ in terms of PGA for return periods 475 and 2475 years are considered in the article.

关键词： Probabilistic seismic hazard assessment Seismic zoning map Peak ground acceleration Seismic sources Seismotectonic setting Seismic regime Ground motion prediction equations