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high spectro-temporal compression on a nonlinear CMOS-chip

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Light(Science & Applications) 2021年第7期10卷 1347-1361页

作者： Ju Won Choi Ezgi Sahin Byoung-Uk Sohn George F.R.Chen Doris K.t.Ng Anuradha M.Agarwal Lionel C.Kimerling dawn t.h.tan Photonics Devices and System Group SUTD-MIT International Design CenterSingapore University of Technology and DesignSingapore 487372Singapore Institute of Microelectronics A*STAR(Agency for ScienceTechnology and Research)2 Fusionopolis Way#08-02Innovis TowerSingapore 138634Singapore Microphotonics Center Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA 02139USA Materials Research Laboratory Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA 02139USA Department of Materials Science and Engineering Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA 02139USA

Optical pulses are fundamentally defined by their temporal and spectral *** ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology,high speed optical communications and attosecond ***,we report 11×temporal compression of 5.8 ps pulses to 0.55 ps using a low power of 13.3 *** result is accompanied by a significant increase in the pulse peak power by 9.4×.these results represent the strongest temporal compression demonstrated to date on a complementary metal–oxide–semiconductor(CMOS)*** addition,we report the first demonstration of on-chip spectral compression,3.0×spectral compression of 480 fs pulses,importantly while preserving the pulse *** strong compression achieved at low powers harnesses advanced on-chip device design,and the strong nonlinear properties of backend-CMOS compatible ultra-silicon-rich nitride,which possesses absence of two-photon absorption and 500×larger nonlinear parameter than in stoichiometric silicon nitride *** demonstrated work introduces an important new paradigm for spectro-temporal compression of optical pulses toward turn-key,on-chip integrated systems for all-optical pulse control.

关键词： pulse optical nonlinear

3D printed on-chip microtoroid resonators and nested spiral photonic devices

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Photonics Research 2021年第9期9卷 1803-1810页

作者： hONGWEI GAO GEORGE F.R.ChEN PENG XING JU WON ChOI dawn t.h.tan Photonics Devices and Systems Group Singapore University of Technology and DesignSingapore 487372Singapore Institute of Microelectronics A*STARSingapore 138634Singapore

An integrated polymer microtoroid resonator system fabricated using single-step,two-photon polymerization laser lithography is *** integrated microtoroid-waveguide system includes an integrated coupling waveguide for ease of optical coupling and has a quality factor of 16,*** further demonstrate a nested doublespiral waveguide that allows higher spatial density of data,akin to a macroscopic form of space-division *** characterization reveals good transmission properties in the double-spiral waveguide *** addition,the waveguides are demonstrated to support 30 Gb/s nonreturn-to-zero and 28 Gb/s pulse amplitude modulation 4 high-speed data.

关键词： Gb/s waveguide resonator

thermo-optically tunable spectral broadening in a nonlinear ultra-silicon-rich nitride Bragg grating

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Photonics Research 2021年第4期9卷 596-604页

作者： Yanmei Cao Ezgi Sahin Ju Won Choi Peng Xing George F.R.Chen D.K.t.Ng Benjamin J.Eggleton dawn t.h.tan Photonics Devices and Systems Group Singapore University of Technology and Design8 Somapah RoadSingapore 487372Singapore Current address:Photonic Systems Laboratory(PhOSL) Ecole Polytechnique Fédérale de LausanneSTI-IELStation 11CH-1015 LausanneSwitzerland Institute of Microelectronics A*STAR2 Fusionopolis Way#08-02Innovis TowerSingapore 138634Singapore Institute of Photonics and Optical Science School of PhysicsThe University of SydneySydneyNew South Wales 2006Australia the University of Sydney Nano Institute(Sydney Nano) The University of SydneySydneyNew South Wales 2006Australia

Spectral tunability methods used in optical communications and signal processing leveraging optical,electrical,and acousto-optic effects typically involve spectral truncation that results in energy *** we demonstrate temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel *** operating at frequencies close to the grating band edge,in an apodized Bragg grating,we access strong grating-induced dispersion while maintaining low losses and high *** further exploit the redshift in the Bragg grating stopband due to the thermo-optic effect to achieve tunable dispersion,leading to varying degrees of soliton-effect compression and self-phase-modulation-induced spectral *** observe an increase in the bandwidth of the output pulse spectrum from 69 to 106 nm as temperature decreases from 70℃ to 25℃,in good agreement with simulated results using the generalized nonlinear Schrödinger *** demonstrated approach provides a new avenue to achieve on-chip laser spectral tuning without loss in pulse energy.

关键词： tunable tuning nonlinear

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI h.GhANDVAR E.JUMAEV S.KhAtIR t.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. the strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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Numerical simulation of triaxial compression test for brittle rock sample using a modified constitutive law considering degradation and dilation behavior

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Journal of Central South University 2015年第8期22卷 3097-3107页

作者：谭鑫 KONIEtZKY h FRühWIRt t College of Civil Engineering Hunan University Geotechnical Institute TU Bergakademie Freiberg

the understanding of the rock deformation and failure process and the development of appropriate constitutive models are the basis for solving problems in rock engineering. In order to investigate progressive failure behavior in brittle rocks, a modified constitutive model was developed which follows the principles of the continuum damage mechanics method. It incorporates non-linear hoek-Brown failure criterion, confining pressure-dependent strength degradation and volume dilation laws, and is able to represent the nonlinear degradation and dilation behaviors of brittle rocks in the post-failure region. A series of triaxial compression tests were carried out on Eibenstock(Germany) granite samples. Based on a lab data fitting procedure, a consistent parameter set for the modified constitutive model was deduced and implemented into the numerical code FLAC3 D. the good agreement between numerical and laboratory results indicates that the modified constitutive law is well suited to represent the nonlinear mechanical behavior of brittle rock especially in the post-failure region.

关键词： progress failure strength degradation dilation hoek-Brown criterion numerical simulation brittle rock

Leveraging ROtI map derived from Indonesian GNSS receiver network for advancing study of Equatorial Plasma Bubble in Southeast/East Asia

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Earth and Planetary Physics 2025年第1期9卷 101-116页

作者： Prayitno Abadi Ihsan N.Muafiry teguh N.Pratama Angga Y.Putra Suraina Gatot h.Pramono Sidik t.Wibowo Febrylian F.Chabibi Umar A.Ahmad Wildan P.tresna Asnawi Research Center for Climate and Atmosphere Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia School of Electrical Engineering Telkom UniversityBandungIndonesia Directorate of Laboratory Management Facilities and Science and technology Park Indonesian National Research and Innovation Agency(BRIN)PontianakIndonesia Geophysics Laboratory Master Program in PhysicsUniversitas Gadjah Mada(UGM)YogyakartaIndonesia Research Center for Space Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia Indonesian Geospatial Information Agency(BIG) JakartaIndonesia Research Center for Photonics Indonesian National Research and Innovation Agency(BRIN)Tangerang SelatanIndonesia Department of Earth and Planetary Sciences Hokkaido UniversitySapporoJapan

this paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning *** by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude ***-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast *** provide a practical tool for EPB research,by sharing two-dimensional rate of total Electron Content(tEC)change index(ROtI)derived from this *** generate ROtI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific *** preliminary findings from the ROtI maps of Ina-CORS are ***,the Ina-CORS ROtI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther ***,we demonstrate that combined ROtI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East *** have demonstrated the combined ROtI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,*** observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities *** sharing ROtI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionosphe

关键词： Equatorial Plasma Bubble(EPB) GNSS receivers’network Indonesia Continuously Operating Reference Station(Ina-CORS) ionospheric map Rate of tEC change index(ROtI)map

Phase transition and dynamics of iron under ramp wave compression

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Acta Mechanica Sinica 2018年第5期34卷 902-909页

作者： t.Chong Z.P.tang F.L.tan G.J.Wang J.h.Zhao Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621999China

the ramp wave compression experiments of iron with different thicknesses were performed on the magnetically driven ramp loading device *** simulations of this process were done with hayes multi-phase equation of state (h-MEOS) and dynamic equations of phase *** calculated results of h-MEOS are in good agreement with those of shock phase transition,but are different from those under ramp wave *** reason for this is that the bulk modulus of the material in the hayes model and the wave velocity are considered *** compression is a jump from the initial state to the final state,and the sound speed is related to the slope of the Rayleigh ***,ramp compression is a continuous process,and the bulk modulus is no longer a constant but a function of pressure and *** on Mumaghan equation of state,the first-order correction of the bulk modulus on pressure in the hayes model was carried *** numerical results of the corrected h-MEOS agree well with those of pure iron in both ramp and shock compression phase transition *** calculated results show that the relaxation time of iron is about 30 ns and the phase transition pressure is about 13 *** are obvious differences between the isentropic and adiabatic process in terms of pressure-specific volume and *** fluctuation of the sound speed after 13 GPa is caused by the phase transition.

关键词： Ramp wave compression Polymorphic phase transition Multiphase equation of state Sound speed

Evaluation of antiviral activities of houttuynia cordata ***,quercetin,quercetrin and cinanserin on murine coronavirus and dengue virus infection

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Asian Pacific Journal of tropical Medicine 2016年第1期9卷 1-7页

作者： K.h.Chiow M.C.Phoon thomas Putti Benny K.h.tan Vincent t.Chow Department of Microbiology Department of Pathologyand Department of PharmacologyYong Loo Lin School of MedicineNational University Health SystemNational University of Singapore

Objective:to evaluate the in vitro activities of the ethyl acetate(EA) fraction of houttuynia cordata(***) thunb.(Saururaceae) and three of its constituent flavonoids(*** and rutin) against murine coronavirus and dengue virus(DENV).Methods:the antiviral activities of various concentrations of the EA fraction of *** and flavonoids were assessed using virus neutralization tests against mouse hepatitis virus(MhV) and DENV type 2(DENV-2).Cinanserin hydrochloride was also tested against *** EA fraction of *** was tested for acute oral toxicity in C57BL/6 ***:the EA fraction of *** inhibited viral infectivity up to 6 *** hydrochloride was able to inhibit MhV for only 2 *** 50%inhibitory concentrations(IC_(50)) of the EA fraction of *** added before the viral adsorption stage were 0.98 μg/mL for MhV and 7.50 μg/mL for DENV-2with absence of *** mice fed with the EA fraction up to 2 000 mg/kg did not induce any signs of acute toxicity,with normal histological features of major *** flavonoids exhibited comparatively weaker antiviral activity,notably quercetin which could inhibit both MhV and *** was followed by quercitrin which could inhibit DENV-2but not MhV,whereas rutin did not exert any inhibitory effect on either *** quercetin was combined with quercitrin,enhancement of anti-DENV-2 activity and reduced cytotoxicity were ***,the synergistic efficacy of the flavonoid combination was still less than that of the EA ***:the compounds in *** contribute to the superior antiviral efficacy of the EA fraction which lacked cytotoxicity in vitro and acute toxicity in *** has much potential for the development of antiviral agents against coronavirus and dengue infections.

关键词： houttuynia cordata Murine coronavirus Dengue virus Quercetin Quercetrin Cinanserin

OXIDAtION BEhAVIOR OF Ni_3Al AND NiAl ALLOYS CONtAINING Fe ADDItIONS

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 641-645页

作者： J.t.Guo S.h. Wang h. Li W.h. Lai and M.h.tan(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, ) Inst of Metal Research Chinese Acad of Sciences Shenyang China

the isothermal oxidation behavior of Ni_3Al containtng 15 at.% Fe and NiAl containing 30 at.% Fe was studied for 100 h at 850, 950, 1050 and 1150℃, respectively. the results show that the oxidation kinetics of the two alloys obey a parabolic law at various temperatures and every parabolic curve possesses two oxidation rate constants. the morphology, microstructure and the chemical composition of the oxide scales were examined using optical metallography, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. the oxide scale of Ni_3Al containing 15 at.% Fe consists mainly of NiO, NiFe_2O_4, and FeAl_2O_4, and that of NiAl containing 30 at.% Fe consists of Fe_2O_3 and (Fe,Ni)Fe_2O_4, contrasting sharply to the oxide scales of pure Ni_3Al and NiAl which consist of Al_2O_3. the oxide scales on the surfaces of Ni_3Al and NiAl containing Fe are not too dense and not too cohesive to the matrix,so their oxidation resistance is not too good.

关键词： oxidation kinetics Ni_3Al-Fe,NiAl-Fe