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A CDR System Based on Improved Second Order Digital Filter, Hysteretic Voter and Phase Interpolator

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Chinese Journal of Electronics 2019年第6期28卷 1227-1233页

作者： ZHAO Yuyue JIANG Yingdan YANG Yu SHEN Guangzhen HU kai YAN Hua East technologies Incorporated China Electronics Technology Group Corporation No.58 Research institute

The proposed Clock and data recovery system(CDRS) has three improved parts. The second order digital filter with rounding algorithm implements fractional gain and avoids direct current quantization noise which varies between –q/2 and +q/2 while that of traditional filter varies between 0 and +q(q is quantization step). The hysteresis majority voter can combat high frequency and strong jitter especially in quasi-steady state. The improved Phase interpolator(PI) has much smaller current-switching glitch and phase glitch since the weighting current changes gradually instead of *** optimized CDRS can handle up to ±6000 ppm(parts per million) frequency offset and the phase resolution is ■/LSB(Least significant bit) according to analysis. The simulations of jitter transfer function and jitter tolerance by Matlab, simulations of phase noise by spectre using Verilog+Verilo A model, and measurements of frequency offset and jitter tolerance all show its good performance.

关键词： CDRS Bang-bang phase detector(!!PD) Hysteretic voter Second order digital filter Phase interpolator Jitter transfer Jitter tolerance

Solid rocket propulsion technology for de-orbiting spacecraft

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Chinese Journal of Aeronautics 2022年第3期35卷 128-154页

作者： Adam OKNINSKI Center of Space technologies Lukasiewicz Research Network-Institute of AviationWarsaw 02-256Poland

This paper presents the topic of using solid rocket propulsion for de-orbiting spacecraft,in order to fulfil space debris mitigation *** benefits and disadvantages of using such means are discussed.A dedicated system can be implemented in the satellite design phase and shall be a key subsystem of platforms inserted into ***,semi-controlled and controlled de-orbit can be completed using solid rocket *** impact on the space debris environment is *** requirements for dedicated propellants and systems are *** the majority of presently developed rocket systems worldwide require high burn rates,several applications,including de-orbiting,benefit from solid propellants with decreased regression *** allows limiting spacecraft accelerations and loads during de-orbit ***,the requirement of minimising solid particle generation is *** technology from the Mercury and Gemini human spaceflight programmes,where de-orbit motors were used,is *** Soviet,American and Chinese film-return-capsule solid propellant retrorockets,enabling deorbit,are also presented.A detailed survey of current work worldwide on end-of-life disposal using solid propulsion is *** of developing dedicated systems are ***,an outlook on solid rocket motor utilisation for space debris mitigation is provided.

关键词： De-orbit De-orbiting technology End-of-life disposal Satellite propulsion system development Solid propellant Solid rocket motor Space debris mitigation Space traffic management

High Q-factor reconfigurable microresonators induced in side-coupled optical fibres

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Light(Science & Applications) 2023年第12期12卷 1867-1876页

作者： Victor Vassiliev Michael Sumetsky Aston institute of Photonic technologies Aston UniversityBirmingham B47ETUK

High Q-factor monolithic optical microresonators found numerous applications in classical and quantum optical signal processing,microwave photonics,ultraprecise sensing,as well as fundamental optical and physical ***,due to the solid structure of these microresonators,attaining the free spectral range tunability of most of them,critical for several of these applications,was,so far,*** address this problem,here we experimentally demonstrate that the side-coupling of coplanar bent optical fibres can induce a high Q-factor whispering gallery mode optical *** changing the curvature radius of fibres from the centimetre order to the millimetre order,we demonstrate fully mechanically reconfigurable optical microresonators with dimensions varying from the millimetre order to 100-micron order and free spectral range varying from a picometre to ten picometre *** developed theory describes the formation of the discovered microresonators and their major properties in a reasonable agreement with the experimental *** new microresonators may find applications in cavity QED,microresonator optomechanics,frequency comb generation with tuneable repetition rate,tuneable lasing,and tuneable processing and delay of optical pulses.

关键词： reconfigurable resonator repetition

Microfracture Characterization in Sandstone Reservoirs:A Case Study from the Upper Triassic of Syria's Euphrates Graben

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Journal of Earth Science 2022年第4期33卷 901-915页

作者： Ibrahem Yousef Vladimir Morozov Vladislav Sudakov Ilyas Idrisov institute of Geology and Petroleum technologies Kazan Federal UniversityKazan 420111Russia

The Euphrates Graben is located in eastern *** Upper Triassic Mulussa F Formation sandstones serve as the primary reservoir intervals in the majority of the graben *** study’s findings were based on core studies:petrographic examination of thin sections,scanning electron microscope(SEM),imaging of backscatter scanning electron microscope(BSE),X-ray microprobe examinations,and carbon-oxygen stable isotope analysis of microfracture-filling *** of the most common types of microfracture found in the investigated sandstones are intragranular or intracrystalline microfractures,grain boundary or grain-edge microfractures,and transgranular(crossing grains)*** microfractures that are open and free of secondary mineralization improve sandstone storage and ***,microfractures that are cemented and filled with secondary mineralization reduce storage and *** siderite and pyrite cements were identified within the microfractures and the nearby sandstone *** anhedral or euhedral siderites are thought to form during shallow burial diagenesis,whereas poikilotopic siderites are thought to form during deep burial *** pyrite is believed to be a diagenetic cement,which is attributed to the reduction of iron oxides present in the sediments in the presence of *** reflect tectonic,overpressure,and diagenetic *** of tectonic origin are associated with folding and thrust activities over the Euphrates Graben area,and they were formed at the beginning of the Upper Triassic with siderite and pyrite cement equilibration temperatures of approximately 100–105℃,and they continued forming from the middle to the end of the Upper Triassic with cement equilibration temperatures of approximately 90–100℃in conjunction with the first phase of the Euphrates *** related to diagenetic and overpressure processes are tension microfractures and wer

关键词： microfracture sandstone Upper Triassic Mulussa F Euphrates Graben Syria

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Raman spectroscopy in crop quality assessment: focusing on sensing secondary metabolites: a review

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Horticulture Research 2023年第5期10卷 282-296页

作者： Miri Park Annette Somborn Dennis Schlehuber Volkmar Keuter Görge Deerberg Fraunhofer institute for Environmental Safety and Energy Technologies UMSICHT46047OberhausenGermany

As a crop quality sensor,Raman spectroscopy has been consistently proposed as one of the most promising and non-destructive methods for qualitative and quantitative analysis of plant substances,because it can measure molecular structures in a short time without requiring pretreatment along with simple *** sensitivity of the Raman spectrum to target chemicals depends largely on the wavelength,intensity of the laser power,and exposure *** for plant samples,it is very likely that the peak of the target material is covered by strong fluorescence ***,methods using lasers with low energy causing less fluorescence,such as 785 nm or near-infrared,are vigorously ***,advanced techniques for obtaining more sensitive and clear spectra,like surface-enhanced Raman spectroscopy,time-gated Raman spectroscopy or combination with thin-layer chromatography,are being *** interpretations of plant quality can be represented not only by the measurement conditions but also by the spectral analysis *** to date,there have been attempted to optimize and generalize analysis *** review summarizes the state of the art of micro-Raman spectroscopy in crop quality assessment focusing on secondary metabolites,from in vitro to in vivo and even in situ,and suggests future research to achieve universal application.

关键词： spectroscopy qualitative likely

Zero-Point Motions in Trans-Polyacetylene

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Chinese Physics Letters 1998年第9期15卷 674-676页

作者： FU Rong-tang RAO Xue-song SUN Xin Y.Kawazoe Department of Physics Fudan UniversityShanghai 2004331 institute for Materials Research Tohoku UniversitySendai 980-77Japan

In order to substantiate the applicability of the Takayama-Lin-Liu-Maki model to conducting polymer,the Su-Schrieffer-Heeger model is generalized to include the effects of lattice zero-point motions on electronic *** the treatment of the white-noise approximation,some significant electronic properties of Peierls-Fröhlich states are *** finding shows that the correlation of lattice motions suppresses the effects of zero-point motions on the electronic properties more seriously.

关键词： properties lattice electronic

Frequency Switches at Transition Temperature in Voltage-Gated Ion Channel Dynamics of Neural Oscillators

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Chinese Physics Letters 2018年第5期35卷 152-155页

作者： Yasuomi D.Sato Department of System Information Sciences Graduate School of Information Sciences Tohoku University institute of Industrial Science University of Tokyo

Understanding of the mechanisms of neural phase transitions is crucial for clarifying cognitive processes in the brain. We investigate a neural oscillator that undergoes different bifurcation transitions from the big saddle homoclinic orbit type to the saddle node on an invariant circle type, and the saddle node on an invariant circle type to the small saddle homoclinic orbit type. The bifurcation transitions are accompanied by an increase in thermodynamic temperature that affects the voltage-gated ion channel in the neural oscillator. We show that nonlinear and thermodynamical mechanisms are responsible for different switches of the frequency in the neural oscillator. We report a dynamical role of the phase response curve in switches of the frequency, in terms of slopes of frequency-temperature curve at each bifurcation transition. Adopting the transition state theory of voltagegated ion channel dynamics, we confirm that switches of the frequency occur in the first-order phase transition temperature states and exhibit different features of their potential energy derivatives in the ion channel. Each bifurcation transition also creates a discontinuity in the Arrhenius plot used to compute the time constant of the ion channel.

关键词： Frequency Switches at Transition Temperature in Voltage-Gated Ion Channel Dynamics of Neural Oscillators

Surface Texturing of TiO_2 Film by Mist Deposition of TiO_2 Nanoparticles

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Nano-Micro Letters 2013年第2期5卷 129-134页

作者： Gang Qin Akira Watanabe institute of Multidisciplinary Research for Advanced Materials Tohoku University School of Materials Science and Engineering Henan Polytechnic University

Unique and various microstructures of titanium oxide(TiO_2 ) film including macroporous structure, chromatic veins and rings, have been easily fabricated by mist deposition method on silicon substrate with mild preparation conditions. Rutile phase TiO_2 nanoparticles were directly used as starting material to prepare film and led to a simple preparation process. It was found that several different microstructures existed in the sample and changed with the varied positions from the center to the edge of the film when the concentration of the TiO_2 suspension is 0.06 mol/l, the deposition time is 30 min, the flow rate is 1 l/min and the temperature is150. The surface texturing shows apparent distinction as the concentration of the TiO_2 suspension decreased to 0.03 mol/l and 0.01 mol/l.

关键词： Mist deposition TiO2 film TiO2 nanoparticle Surface texturing Microstructure

Bi-based superconductors fabricated in high magnetic fields

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中国有色金属学会会刊：英文版 2006年第B01期16卷 11-19页

作者： LU XY A. NAGATA K. SUGAWARA K. WATANABE T. NOJIMA Faculty of Engineering and Resource Science Akita University Akita 010-8502 Japan institute for Materials Research Tohoku University Sendai 980-8577 Japan Center for Low Temperature Science Tohoku University Sendai 980-8577 Japan

The microstructure and superconducting properties of Bi-2223 superconductor fabricated in high magnetic fields were investigated. The results shows that the Bi-2212 grains with their c-axis parallel to the magnetic field were formed after the partial-melting and solidification in 8 T magnetic field, and transformed into the Bi-2223 grains with c-axis alignment during the further sintering process at 840 ℃ without magnetic field. The conversion of Bi-2212 grains to Bi-2223 grains has the heredity in grain alignment. The mixed structures of the Bi-2223 and the Bi-2212 grains with their c-axis parallel to the magnetic field are formed in samples sintered at 850?855 ℃ in 10 T magnetic field. When sintered in 10 T below 845 ℃, a high proportion of Bi-2223 phase is obtained, however no preferred orientation is observed. The Bi-2223 grains with their c-axis parallel to the axial direction of the vertical tube furnace are formed not only on the surface, but also in the center of the sample sintered at 850 ℃ for 120 h in a 15 ℃/cm temperature gradient without magnetic field. Moreover, the samples sintered in the temperature gradient and in a 10 T magnetic field have a stronger c-axis alignment of Bi-2223 phase.

关键词：铋基超导体制造铋-2223 磁场显微结构