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Optical spectroscopy study of charge density wave order in Sr3Rh4Sn13 and(Sr0.5ca0.5)3Rh4Sn13

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Science china(Physics,Mechanics & Astronomy) 2017年第4期60卷 51-56页

作者： W.J.Ban H.E Wang c.W.Tseng c.n.Kuo c.S.Lue n.L.Wang Institute of Physics Chinese Academy of SciencesBeijing 100190China Department of Physics Cheng Kung UniversityTainan 70101China International center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China collaborative Innovation center of Quantum Matter Beijing 100871China

We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5ca0.5）3Rh4Sn13. Formation of cDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions. The existence of residual Drude components in σ1（ω） below Tcow indicates that the Fermi surface is only partially gapped in the cDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5ca0.5）3Rh4Sn13 compounds, which is considerably larger than the mean-field value based on the weak-coupling BcS theory. The measurements provide optical evidence for the strong coupling characteristics of the cDW phase transition.

关键词： charge density wave optical spectroscopy intermetallic compounds

A novel Big Data Storage Reduction Model for Drill Down Search

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computer Systems Science & Engineering 2022年第4期41卷 373-387页

作者： n.Ragavan c.Yesubai Rubavathi Department of computer Science and Engineering Francis Xavier Engineering CollegeAnna UniversityTamil NaduIndia

Multi-level searching is called Drill down *** now,no drill down search feature is available in the existing search engines like Google,Yahoo,Bing and *** down search is very much useful for the end user toﬁnd the exact search results among the huge paginated search *** level of drill down search with category based search feature leads to get the most accurate search results but it increases the number and size of theﬁle *** purpose of this manuscript is to implement a big data storage reduction binaryﬁle system model for category based drill down search engine that offers fast multi-levelﬁltering *** basic methodology of the proposed model stores the search engine data in the binaryﬁle system *** verify the effectiveness of the proposedﬁle system model,5 million unique keyword data are stored into a binaryﬁle,thereby analysing the proposedﬁle system with efﬁ*** experimental results are also provided based on real data that show our storage model speed and *** demonstrated that ourﬁle system expansion ratio is constant and it reduces the disk storage space up to 30%with conventional database/ﬁle system and it also increases the search performance for any levels of *** discuss deeply,the paper starts with the short introduction of drill down search followed by the discussion of important technologies used to implement big data storage reduction system in detail.

关键词： Big data drill down search storage reduction model binaryﬁle system

Simulation of old open clusters for UVIT on ASTROSAT

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Research in Astronomy and Astrophysics 2015年第10期15卷 1647-1670页

作者： Sindhu n Annapurni Subramaniam Anu Radha c School of Advanced Sciences VIT University Indian Institute of Astrophysics

The Ultra Violet Imaging Telescope （UVIT） is one of the payloads on the first Indian multiwavelength satellite ASTROSAT, which is expected to be launched by the Indian Space Research Organisation （ISRO） in the year 2015. We have per- formed simulations of UV studies of old open clusters for the UVIT. The colour mag- nitude diagrams （cMDs） and spatial appearances have been created using 10 filters associated with the FUV channel （130-180 nm） and nUV channel （200-300 nm） that are available for observations on the UVIT, for the three old open clusters M67, nGc 188 and nGc 6791. The cMDs are simulated for different filter combinations, and they are used to identify the loci of various evolutionary sequences, white dwarfs, blue stragglers, red giants, subgiants, turn off stars and the main sequence of the clus- ters. The present work helps in identifying a potential area of study in the case of these three old open clusters by considering the availability of filters and the detection limits of the instrument. We also recommend filter combinations, which can be used to detect and study the above mentioned evolutionary stages. The simulations and the results presented here are essential for the optimal use of the UVIT for studies of old open clusters.

关键词： (stars:) blue stragglers -- (stars:) Hertzsprung-Russell and c-M diagrams-- (stars:) white dwarfs -- (Galaxy:) open clusters and associations: individual (M67,nGc 188 nGc 6791) -- ultraviolet: stars

Long-term patterns in Iberian hare population dynamics in a protected area(Doñana national Park)in the southwestern Iberian Peninsula:Effects of weather conditions and plant cover

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Integrative Zoology 2017年第1期12卷 49-60页

作者： Francisco cARRO Ramón c.SORIGUER Doñana Biological Station(cSIc) the Monitoring Team on Natural Resources and Processes of the Doñana Biological Station Ethology and Biodiversity conservation SevillaSpain

The Iberian hare(Lepus granatensis)is a widely distributed endemic species in the Iberian *** improve our knowledge of its population dynamics,the relative abundance and population trends of the Iberian hare were studied in the autumns of 1995-2012 in a protected area(Doñana national Park)by spotlighting in 2 different habitats:marshland and *** average relative abundance was 0.38 hare/km(SD=0.63)in the marshland and 3.6 hares/km(SD=4.09)in *** Iberian hare population exhibited local interannual fluctuations and a negative population trend during the study period(1995-2012).The results suggest that its populations are in *** flooding of parts of the marshland in June,July and October favor hare abundance in the *** abundance in the marshland increases as the flooded surface area increases in *** effects are more pronounced if the rains are early(October)and partially flood the *** contrast,when marsh grasses and graminoids are very high and thick(as measured using the aerial herbaceous biomass[biomass marshland]as a proxy),the abundance of hares decreases dramatically as does the area of the marsh that is flooded(in november).

关键词： Doñana Iberian Peninsula Lepus granatensis population dynamics trends

Topology optimization of piezoelectric bi-material actuators with velocity feedback control

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Frontiers of Mechanical Engineering 2019年第2期14卷 190-200页

作者： Mariana MORETTI Emilio c.n.SILVA School of Engineering University of Sao PauloSao PauloSP 05508-030Brazil

In recent years,the new technologies and discoveries on manufacturing materials have encouraged researchers to investigate the appearance of material properties that are not naturally *** featuring a specific stiffness,or structures that combine non-structural and stmctural functions are applied in the aerospace,electronics and medical industry ***,structures designed for dynamic actuation with reduced vibration response are the focus of this *** bi-material and multifunctional concepts are considered for the design of a controlled piezoelectric actuator with vibration suppression by means of the topology optimization method(TOM).The bi-material piezoelectric actuator(BPEA)has its metallic host layer designed by the TOM,which defines the structural function,and the electric function is given by two piezo-ceramic layers that act as a sensor and an actuator coupled with a constant gain active velocity feedback control(AVFc).The AVFc,provided by the piezoelectric layers,affects the structural damping of the system through the velocity state variables readings in time *** dynamic equation analyzed throughout the optimization procedure is fully elaborated and *** dynamic response for the rectangular fbur-noded finite element analysis is obtained by the newmark's time-integration method,which is applied to the physical and the adjoint systems,given that the adjoint formulation is needed for the sensitivity analysis.A gradient-based optimization method is applied to minimize the displacement energy output measured at a predefined degree-of-freedom of the BPEA when a transient mechanical load is *** are obtained for different control gain values to evaluate their influence on the final topology.

关键词： topology optimization method bi-material piezoactuator active velocity feedback control timedomain transient analysis host structure design vibration suppression

THE STRESS-EnERGY TEnSOR AnD POHOZAEV'S IDEnTITY FOR SYSTEMS

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Acta Mathematica Scientia 2012年第1期32卷 433-439页

作者： n.D.Alikakos A.c.Faliagas Department of Mathematics University of Athens

Utilizing stress-energy tensors which allow for a divergence-free formulation, we establish Pohozaev＇s identity for certain classes of quasilinear systems with variational structure.

关键词： calculus of variations stress-energy tensor p-Lapacian minimal surface

characteristics of a Gan-based Gunn diode for THz signal generation

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Journal of Semiconductors 2012年第8期33卷 37-43页

作者： R K Parida n c Agrawala G n Dash A K Panda ITER Siksha‘O'Anusandhan University Rengali college Sambalpur University national Institute of Science&Technology

A generalized large-signal computer simulation program for a Gunn oscillator has been developed. The properties of a Gunn diode oscillator based on the widely explored Gan, are investigated using the developed program. The results show some interesting properties in Gan Gunn diodes which are not seen in GaAs and InP diodes. An output power of 1400 kW/cm^2 is achieved from the Gan Gunn diode, as compared to 4.9 kW/cm^2 from a GaAs diode.

关键词： Gunn devices semiconductor diodes semiconductor materials power Gan

3D tomographic analysis of equatorial plasma bubble using GnSS-TEc data from Indonesian GnSS network

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Earth and Planetary Physics 2025年第1期9卷 127-136页

作者： Ihsan naufal Muafiry Prayitno Abadi Teguh n.Pratama Dyah R.Martiningrum Sri Ekawati Yuandhika GWismaya Febrylian Fchabibi Gatot HPramono Research center for climate and Atmosphere Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia Indonesian Geospatial Information Agency(BIG) JakartaIndonesia Dept.of Physics Faculty of ScienceUniversiti Teknologi MalaysiaJohor BahruMalaysia Dept.Earth Planet Sci. Hokkaido UniversitySapporoJapan School of Electrical Engineering Telkom UniversityBandungIndonesia

Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic *** most commonly occur after sunset during the equinox months,although they can also be observed during other *** phenomenon significantly disrupts radio wave signals essential to communication and navigation *** national network of Global navigation Satellite System(GnSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB *** explore this,we conducted preliminary 3D tomography of total electron content(TEc)data captured by GnSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian *** and extracted TEc depletion with a 120-minute running average were then used as inputs for a 3D tomography *** 2D spatial distribution consistently captured the four EPB clusters over *** tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)*** of the results demonstrates the capability of the Indonesian GnSS network to measure peak ionospheric *** findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GnSS networks,with extensive longitudinal coverage.

关键词： EPB Indonesian GnSS network 3D tomography

Detection of Low Sugar concentration Solution Using Frequency Selective Surface (FSS)

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computers, Materials & continua 2022年第5期71卷 2869-2882页

作者： n.S.Ishak F.c.Seman n.Zainal n.A.Awang Faculty of Electrical and Electronics Engineering Universiti Tun Hussein Onn MalaysiaParit RajaBatu Pahat86400Malaysia Research center for Applied Electromagnetics(EMcenter) The Institute of Integrated EngineeringUniversiti Tun Hussein Onn MalaysiaParit RajaBatu Pahat86400Malaysia Microelectronic and nanotechnology-Shamsuddin Research centre(MinT-SRc) The Institute of Integrated EngineeringUniversiti Tun Hussein OnnParit RajaBatu Pahat86400Malaysia Photonics Devices and Sensor Research(PDSR) Faculty of Applied Science and Technology(FAST)Universiti Tun Hussein Onn Malaysia(Pagoh Campus)JorakBukit Pasir84500Malaysia

Sugar is important in daily food intake since it is used as food preservative and ***,is important to analyze the influence of sugar on the spectroscopic properties of the *** spectroscopy is proven to be useful and an efficient method for sugar detection as well as for future food quality ***,the lack of detection sensitivity in Terahertz Spectroscopy has prevented it from being used in a widespread spectroscopic analysis *** this paper,Frequency Selective Surface(FSS)using the Terahertz Spectroscopy Time Domain Spectrum(THz-TDS)which operates at terahertz frequency range has been demonstrated for application of sugar *** FSS is designed with a circle slot structure and has been optimized in line with the molecular resonance of glucose and fructose at different level concentration at 1.98 THz and 1.80 THz,*** magnitude of glucose and sucrose is inversely proportional with the level of sugar *** realization of the FSS structure is using electron beam lithography and wet etching *** show that the FSS performance for glucose and sucrose reveal fair shifts in measured transmission magnitude from its original in cST by approximately 30%.The use of fabricated FSS with circle structure indicates that the concentration can be improved averagely at 25%for glucose and 13%for ***,it shows that the FSS circle structure combined with THz-TDS has the potential to become an alternative method for food sensing technology in the future.

关键词： THz sensing FSS circle structure sugar concentration