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Disorder effects in NbTiN superconducting resonators

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Chinese Physics B 2024年第2期33卷 482-486页

作者：吕伟涛支强胡洁李婧史生才 Purple Mountain observatory Chinese Academy of SciencesNanjing 210034China GEPI Observatoire de ParisPSL UniversitéCNRSParis 75014France

Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical temperature(T_(c)),and quasiparticle density of states(QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling,can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the △, Tc, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide(CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T_(c)^(P) of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.

关键词： effects of disorder NbTiN superconducting film Usadel equation complex conductivity superconducting resonator

Stochastic Analysis and Modeling of Velocity Observations in Turbulent Flows

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Journal of Environmental & Earth Sciences 2024年第1期6卷 45-56页

作者： Evangelos Rozos Jorge Leandro Demetris Koutsoyiannis Institute for Environmental Research&Sustainable Development National Observatory of AthensAthens15236Greece Research Institute for Water and Environment University of SiegenSiegen57076Germany Department of Water Resources and Environmental Engineering School of Civil Engineering National Technical University of AthensAthens15780Greece

Highly turbulent water flows,often encountered near human constructions like bridge piers,spillways,and weirs,display intricate dynamics characterized by the formation of eddies and *** formations,varying in sizes and lifespans,significantly influence the distribution of fluid velocities within the ***,the rapid velocity fluctuations in highly turbulent flows lead to elevated shear and normal stress *** this reason,to meticulously study these dynamics,more often than not,physical modeling is employed for studying the impact of turbulent flows on the stability and longevity of nearby *** the effectiveness of physical modeling,various monitoring challenges arise,including flow disruption,the necessity for concurrent gauging at multiple locations,and the duration of *** these challenges,image velocimetry emerges as an ideal method in fluid mechanics,particularly for studying turbulent *** account for measurement duration,a probabilistic approach utilizing a probability density function(PDF)is suggested to mitigate uncertainty in estimated average and maximum ***,it becomes evident that deriving the PDF is not straightforward for all turbulence-induced *** response,this study proposes a novel approach by combining image velocimetry with a stochastic model to provide a generic yet accurate description of flow dynamics in such *** integration enables an approach based on the probability of failure,facilitating a more comprehensive analysis of turbulent *** an approach is essential for estimating both short-and long-term stresses on hydraulic constructions under assessment.

关键词： Smart modeling Turbulent flows Data analysis Stochastic analysis Image velocimetry

UWLPIPE:Ultra-wide Bandwidth Low-frequency Pulsar Data Processing Pipeline

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Research in Astronomy and Astrophysics 2024年第7期24卷 145-157页

作者： Ya-Zhou Zhang Hai-Long Zhang Jie Wang Jian Li Xin-Chen Ye Shuang-Qiang Wang Xu Du Han Wu Ting Zhang Shao-Cong Guo Xinjiang Astronomical observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China national Astronomical Data Center Beijing 100101China Southeast University Nanjing 211189China

For real-time processing of ultra-wide bandwidth low-frequency pulsar baseband data,we designed and implemented an ultra-wide bandwidth low-frequency pulsar data processing pipeline(UWLPIPE)based on the shared ringbuffer and GPU parallel *** runs on the GPU cluster and can simultaneously receive multiple 128 MHz dual-polarization VDIF data packets preprocessed by the front-end *** aligning the dual-polarization data,multiple 128M subband data are packaged into PSRDADA baseband data or multi-channel coherent dispersion filterbank data,and multiple subband filterbank data can be spliced into wideband data after time *** used the Nanshan 26 m radio telescope with the L-band receiver at964~1732 MHz to observe multiple ***,we processed the data using DSPSR software,and the results showed that each subband could correctly fold out the pulse profile,and the wideband pulse profile accumulated by multiple subbands could be correctly aligned.

关键词： (stars)pulsars general-methods data analysis-techniques miscellaneous

Progress Report on ASO-S: 2022–2024

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空间科学学报 2024年第4期44卷 687-689页

作者： GAN Weiqun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023

The Advanced Space-based solar observatory(ASO-S)marked China's first comprehensive solar mission in *** upon the previous reports covering 2018-2020 and 2020-2022,we present here an update on the ASO-S made from 2022 to *** August 2022,ASO-S completed its Phase D study and was successfully launched on October 9,*** commissioning phase was carried out and concluded within the first nine months following the *** data and associated analysis software have been opened to the community and the research on the early ASO-S data has been well *** anticipate also the achievements in data research pertaining to ASO-S in the near future.

关键词： Space astronomy solar physics Spacecraft

A sphingolipid message promotes neuronal health across generations

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Neural Regeneration Research 2024年第11期19卷 2325-2326页

作者： Wenyue Wang Roger Pocock Development and Stem Cells Program Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental BiologyMonash UniversityMelbourneVICAustralia

Maternal nutrition can affect brain function of offspring in later life(Fitzgerald et al.,2020).Emerging studies have also shown that the maternal environment can modify susceptibility to neurodegenerative disease(Boots et al.,2023).Transmission of environmental information from mother to offspring depends on maternal nutrient *** the nematode Caenorhabditis elegans,maternal yolk,which is synthesized in the intestine and transferred to nourish oocytes and early embryos,can provide extranuclear inheritance factors to mediate phenotypic plasticity across ***,the molecular mechanisms of regulating such intergenerational effects remain largely unknown.

关键词： mother intestine transferred

Evaluation and projection of marine heatwaves in the South China Sea: insights from CMIP6 multi-model ensemble

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Acta Oceanologica Sinica 2024年第7期43卷 15-25页

作者： Kai Liu Kang Xu Tongxin Han Congwen Zhu Nina Li Anboyu Guo Xiaolu Huang national Marine Environmental Forecasting Center Beijing 100081China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China national Meteorological Center China Meteorological AdministrationBeijing 100081China Inner Mongolia Autonomous Region Meteorological observatory Huhhot 010051China

This study evaluates the performance of 16 models sourced from the coupled model intercomparison project phase 6(CMIP6)in simulating marine heatwaves(MHWs)in the South China Sea(SCS)during the historical period(1982−2014),and also investigates future changes in SCS MHWs based on simulations from three shared socioeconomic pathway(SSP)scenarios(SSP126,SSP245,and SSP585)using CMIP6 *** demonstrate that the CMIP6 models perform well in simulating the spatial-temporal distribution and intensity of SCS MHWs,with their multi-model ensemble(MME)results showing the best *** reasonable agreement between the observations and CMIP6 MME reveals that the increasing trends of SCS MHWs are attributed to the warming sea surface temperature *** various SSP scenarios,the year 2040 emerges as pivotal juncture for future shifts in SCS MHWs,marked by distinct variations in changing rate and *** is characterized by an accelerated decrease in MHWs frequency and a notably heightened increase in mean intensity,duration,and total days after ***,the projection results for SCS MHWs suggest that the spatial pattern of MHWs remains consistent across future ***,the intensity shows higher consistency only during the near-term period(2021−2050),while notable inconsistencies are observed during the medium-term(2041−2070)and long-term(2071−2100)periods under the three SSP *** the nearterm period,the SCS MHWs are characterized by moderate and strong events with high frequencies and relatively shorter *** contrast,during the medium-term period,MHWs are also characterized by moderate and strong events,but with longer-lasting and more intense events under the SSP245 and SSP585 ***,in the long-term period,extreme MHWs become the dominant feature under the SSP585 scenario,indicating a substantial intensification of SCS MHWs,effectively establishing a near-permanent state.

关键词： marine heatwaves South China Sea global warming future projections CMIP6

Identifying Three New AGNs among Fermi Unidentified Gigaelectronvolt Sources

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Research in Astronomy and Astrophysics 2024年第7期24卷 257-267页

作者： Shun-Hao Ji Zhong-Xiang Wang Qiang-Meng Huang Ruo-Heng Yang Department of Astronomy School of Physics and AstronomyYunnan UniversityKunming 650091China Shanghai Astronomical observatory Chinese Academy of SciencesShanghai 200030China

We report our identification of three gigaelectronvoltγ-ray sources,4FGL J0502.6+0036,4FGL J1055.9+6507,and 4FGL J1708.2+5519,as Active Galactic Nuclei(AGNs).They are listed in the latest Fermi-Large Area Telescope source catalog as unidentified *** find that the sources all showedγ-ray flux variations in recent *** different survey catalogs,we are able to find a radio source within the error circle of each source's *** analysis of optical sources in the fields allows us to determine the optical counterparts,which showed similar variation patterns to those seen inγ-*** optical counterparts have reported redshifts of 0.6,1.5,and 2.3,respectively,estimated from photometric *** addition,we also obtain an X-ray spectrum of 4FGL J0502.6+0036 and a flux upper limit on the X-ray emission of 4FGL J1055.9+6507 by analyzing the archival *** broadband spectral energy distributions of the three sources from radio toγ-rays are *** mainly theγ-ray properties of the three sources with those of different sub-classes of AGNs,we tentatively identify them as *** optical spectroscopy is highly warranted for obtaining their spectral features and thus verifying the identification.

关键词： gamma-rays galaxies-(galaxies)BL Lacertae objects general-(galaxies)quasars general

Electrochemical Dearomative Spirocyclization of N-Acyl Sulfonamides in a Continuous-Flow Cell

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Chinese Journal of Chemistry 2024年第9期42卷 980-984页

作者： Ting Liu Zhaojiang Shi Yaofeng Yuan Yuqi Lin Ke-Yin Ye Key Laboratory of Molecule Synthesis and Function discovery(Fujian Province University) College of ChemistryFuzhou University FuzhouFujian350108China

The development of efficient and sustainable methods to obtain spirocyclic compounds is of significance as these structures are widely found in pharmaceuticals and ***,we disclose an electrochemical dearomative spirocyclization of N-acyl sulfonamides in a continuous-flow *** reaction is simple and efficient without external catalysts or supporting electrolytes and could be applied in a decagram-scale synthesis.

关键词： Electrochemistry Continuous-flow Dearomatization Spirocyclization Sulfonamides Cyclization Methodology and reactions

3D near-surface P-wave velocity structure imaging with Distributed Acoustic Sensing and electric hammer source

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Earthquake Research Advances 2024年第3期4卷 27-33页

作者： Heting Hong Fu Yin Yuhang Lei Yulan Li Baoshan Wang Deep Space Exploration Laboratory University of Science and Technology of ChinaHefei230026China School of Earth and Space Sciences University of Science and Technology of ChinaHefei230026China Mengcheng national Geophysical observatory University of Science and Technology of ChinaHefei230026China

Distributed Acoustic Sensing(DAS) is an emerging technique for ultra-dense seismic observation, which provides a new method for high-resolution sub-surface seismic imaging. Recently a large number of linear DAS arrays have been used for two-dimensional S-wave near-surface imaging in urban areas. In order to explore the feasibility of three-dimensional(3D) structure imaging using a DAS array, we carried out an active source experiment at the Beijing national Earth observatory. We deployed a 1 km optical cable in a rectangular shape, and the optical cable was recast into 250 sensors with a channel spacing of 4 m. The DAS array clearly recorded the P, S and surface waves generated by a hammer source. The first-arrival P wave travel times were first picked with a ShortTerm Average/Long-Term Average(STA/LTA) method and further manually checked. The P-wave signals recorded by the DAS are consistent with those recorded by the horizontal components of short-period seismometers. At shorter source-receiver distances, the picked P-wave arrivals from the DAS recording are consistent with vertical component recordings of seismometers, but they clearly lag behind the latter at greater *** is likely due to a combination of the signal-to-noise ratio and the polarization of the incoming wave. Then,we used the Tomo DD software to invert the 3D P-wave velocity structure for the uppermost 50 m with a resolution of 10 m. The inverted P-wave velocity structures agree well with the S-wave velocity structure previously obtained through ambient noise tomography. Our study indicates the feasibility of 3D near-surface imaging with the active source and DAS array. However, the inverted absolute velocity values at large depths may be biased due to potential time shifts between the DAS recording and seismometer at large source-receiver distances.

关键词： Distributed Acoustic Sensing(DAS) Near-surface structure First-arrival travel time tomography Body wave Active source