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国际医学放射学杂志 2024年第3期 378-379页

作者： Y.Lu R.Cao s.jiao L.Li C.Liu H.Hu 孔令红

摘要目的评价黑血CT(BBCT)在颈动脉壁成像中的应用及其显示颈动脉狭窄率和斑块负荷的准确性。方法共有110例病人接受了2期CT增强扫描，采用对比强化增益

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前期工艺对冷轧退火Mo-Nb微合金TRIP钢的影响

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现代冶金（内蒙古） 2005年第1期 57-62页

作者： s.jiao 王荣刘畅加拿大不详

本文对Mo-Nb微合金TRIP钢进行几种热处理以产生不同的微观组织。再将不同微观组织试样进行冷轧和退火，然后进行拉伸试验和残余奥氏体特性测定。试验结果表明，预备热处理对冷轧和退火后钢的性能有显著影响。通常，随着冷轧和退火前钢... 详细信息

本文对Mo-Nb微合金TRIP钢进行几种热处理以产生不同的微观组织。再将不同微观组织试样进行冷轧和退火，然后进行拉伸试验和残余奥氏体特性测定。试验结果表明，预备热处理对冷轧和退火后钢的性能有显著影响。通常，随着冷轧和退火前钢中先共析铁索体数量的增加，钢的拉伸性能提高。这是由于加工硬化率增高，进而导致残余奥氏体中碳富集增大。我们可以利用这些结果对热轧工艺进行优化，以利于随后生产冷轧Mo-Nb微合金TRIP钢。

关键词：冷轧微合金残余奥氏体 TRIP钢退火微观组织热处理致残前期预备

structural build-up model for three-dimensional concrete printing based on kinetics theory

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Frontiers of structural and Civil Engineering 2024年第7期18卷 998-1014页

作者： Prabhat Ranjan PREM P.s.AMBILY shankar KUMAR Greeshma GIRIDHAR Dengwu jiao Advanced Materials Laboratory CSIR-Structural Engineering Research CentreChennai 600113India Department of Architecture and Civil Engineering City University of Hong KongHong Kong 999077China

The thixotropic structural build-up is crucial in extrusion-based three-dimensional(3D)concrete *** paper uses a theoretical model to predict the evolution of static and dynamic yield stress for printed *** model employs a structural kinetics framework to create a time-independent constitutive link between shear stress and shear *** model considers flocculation,deflocculation,and chemical hydration to anticipate structural *** reversible and irreversible contributions that occur throughout the build-up,breakdown,and hydration are defined based on the proposed structural ***,detailed parametric studies are conducted to evaluate the impact of model *** is revealed that the proposed model is in good agreement with the experimental results,and it effectively characterizes the structural build-up of 3D printable concrete.

关键词： structural build-up rheology thixotropy 3D printable concrete kinetics theory ultra high performance concrete

A Possible γ-Ray Pulsation from PsR J1740-5340B in the Globular Cluster NGC 6397

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Research in Astronomy and Astrophysics 2024年第1期24卷 285-291页

作者： jiao Zheng Pengfei Zhang Li Zhang Department of Astronomy School of Physics and AstronomyKey Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China

Recently, a new radio millisecond pulsar(MsP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray space Telescope and detect PsR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PsR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PsR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MsP J1740-5340A in the GC is *** that the previous four cases of MsPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MsP J1740-5340B, especially starving for a precise ephemeris.

关键词： gamma-rays:galaxies (stars:)pulsars:individual(PsR J1740-5340B) (Galaxy:)globular clusters:individual(NGC 6397)

An axisymmetric characteristic model for enhancing prediction of centrifugal compressor characteristics

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Chinese Journal of Aeronautics 2024年第4期37卷 203-215页

作者： Peng REN Xiangjun FANG Zeyu jiao Ying HAN school of Energy and Power Engineering Beihang UniversityBeijing 100191China Guangdong Key Laboratory of Modern Control Technology Institute of Intelligent ManufacturingGuangdong Academy of SciencesGuangzhou 510070China

Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combinations of loss models, varies significantly depending on the compressor's geometry and operational range. This variance necessitates substantial experimental or Computational Fluid Dynamics(CFD) data for coefficient calibration. To address this challenge, this study presents an axisymmetric characteristic model for compressor performance assessment. This model incorporates the factors of blade angle, meridional passage area, and the radial deflection angle of meridional streamlines of the compressor. These factors are derived from fundamental aerodynamic equations encompassing mass, momentum, and energy conservation of the compressor. In contrast to conventional one-dimensional approaches, the proposed method reduces the number of loss coefficients and more effectively accounts for the impact of geometric alterations on centrifugal compressor properties. Furthermore, the model reduces dependence on experimental and CFD data. Efficacy of the model is validated using experimental data from four distinct types of centrifugal compressors. Correlation analysis reveals that the model's coefficients can be expressed as functions of the ratio of the Reynolds number to the impeller tip speed. This ratio serves as a characteristic parameter for the design and optimization of centrifugal compressors. Consequently, the proposed method offers an efficient and accurate means for the quick computation of centrifugal compressor characteristics. This is of great significance for improving the efficiency of centrifugal compressors and reducing energy consumption.

关键词： Centrifugal compressor Positive problem Characteristic prediction Aerodynamic characteristic Axisymmetric model

Detection of Increasingγ-Ray Emissions from 4FGL J1718.5+4237 with Fermi-LAT

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Research in Astronomy and Astrophysics 2024年第8期24卷 169-174页

作者： jiao Zheng Pengfei Zhang Li Zhang Department of Astronomy School of Physics and AstronomyKey Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China school of Physics and Engineering Technology Xingyi Normal University for NationalitiesXingyi 562400China

We report a gradual brighteningγ-ray source,4FGL J1718.5+4237,in 0.1-500.0 GeV,which may be associated with a blazar NVss J171822+423948 with a redshift of~*** analyzed 15.25 yr ofγ-ray data recorded by the Large Area Telescope on board the Fermi Gamma-ray space Telescope and detected significantγ-ray emissions in the direction of the blazar with a test statistic(Ts)of~*** on timing analysis using a 1 yr time bin,we have observed a gradual brightening inγ-ray emissions from the *** our analysis,we categorize them into two states:Quiet(Ts~0)and Loud(Ts~226)states,with the distinction occurring in 2016 August(MJD57602.69).From the Quiet state to the brightest period(the last data point),theγ-ray flux in 0.1-500.0 GeV increased by more than 12-fold froms cm^(-1)s^(-1)to 2.6×10^(-8)photons cm^(-1)s^(-1).Additionally,we studied the spectral properties in detail for the Loud state and the overall *** no significant variation was detected,both exhibited a spectral indexΓof~*** origin of the brighteningγ-ray emissions from the target is not yet *** long-term multi-wavelength observations and studies will provide insight into the astrophysical mechanisms of the target.

关键词： galaxies active-blazars individual(4FGL J1718.5+4237)

Parametric formation control of multiple nanosatellites for cooperative observation of China space station

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Astrodynamics 2024年第1期8卷 77-95页

作者： Hao Zhou Bohan jiao Zhaohui Dang Jianping Yuan school of Astronautics Northwestern Polytechnical UniversityXi’an710072China National Key Laboratory of Aerospace Flight Dynamics Northwestern Polytechnical UniversityXi’an710072China

This study proposes a parametric formation control method for the cooperative observation of the China space station(Css)using multiple ***,a simplified geometrical model of the Css is constructed using fundamental solids,such as the capsule body and ***,the spacecraft formation configuration for the observation mission is characterized by a three-dimensional(3D)Lissajous curve using related design parameters under the full-coverage observation requirements of specific parts,such as the Css connecting section and collision avoidance ***,a double-layer control law is designed for each nanosatellite,in which the upper layer is a distributed observer for recognizing the target formation configuration parameters,and the lower layer is a trajectory-tracking controller to make the nanosatellite converge to its temporary target position calculated from the upper layer’s *** closed-loop control stability is proven under the condition that the communication network topology of the nanosatellite cluster contains a directed spanning ***,the control method is verified by numerical simulation,where the Css connecting section is selected as the observation target,and ten small nanosatellites are assumed to perform the cooperative observation *** simulation results demonstrate that the double-layer control law is robust to single-point communication failures and suitable for the accompanying missions of large space objects with multiple nanosatellites.

关键词： China space station(Css) cooperative observation parametric formation 3D Lissajous curve double-layer system

Preweaning period is a critical window for rumen microbial regulation of average daily gain in Holstein heifer calves

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Journal of Animal science and Biotechnology 2024年第1期15卷 396-411页

作者： shengyang Xu Chong jiao Qiyu Diao Yan Tu Beijing Key Laboratory for Dairy Cow Nutrition Institute of Feed ResearchChinese Academy of Agricultural SciencesBeijing 100081People’s Republic of China

Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and *** study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different *** calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host *** During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,Pse bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted Psequently raised serum glucose concentrations(adjusted Pst,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this ***,no significant differences were observed in rumen fermentation parameters and serum indices between the two *** The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves.

关键词： Average daily gain Calves Preweaning period Rumen microbiota

Integrated stratigraphy and Mineralogy of the Doushantuo Formation in Weng’an,south China,and Implications for Ediacaran Phosphogenesis

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Journal of Earth science 2024年第2期35卷 476-503页

作者： Liangxuan jiao Zhenbing she Dominic Papineau Yaguan Zhang Matthew s.Dodd Kenan Cao Qun Chen Guoyong Chen state Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430078China school of Earth sciences China University of GeosciencesWuhan430047China London Centre for Nanotechnology University College London17-19 Gordon StreetLondonWC1E 6BTUK Department of Earth sciences University College LondonLondonWC1E 6BTUK Centre for Planetary science University College London and Birkbeck CollegeLondonWC1E 7HXUK Innovation Center of Ore Resources Exploration Technology in the Region of Bedrock Ministry of Natural Resources of People’s Republic of China’Guiyang550000China Guizhou Bureau of Geology and Mineral Exploration and Development Guiyang550000China

The Ediacaran–Cambrian Phosphogenic Episode is the Earth’s first true phosphogenic event and resulted in worldwide phosphate deposits,which occurred during the processes of the Neoproterozoic Oxygenation *** Ediacaran Doushantuo Formation(ca.635–551 Ma)of Weng’an area in central Guizhou,south China,contains two economic phosphorite beds(the Lower and Upper Phosphorite Beds).This paper presents a detailed stratigraphic,sedimentological and mineralogical study of multiple outcrop and drill core sections of the Doushantuo Formation across the Weng’an area,and identified 11 lithofacies and 4 types of phosphatic *** differences in lithofacies and grain types between the upper and lower phosphate deposits are observed,indicating that the two sets of phosphate deposits are the products of two distinct phosphogenic *** Lower Phosphorite Bed mainly consists of banded and laminated phosphorites,contains micro-oncoids formed by microbially-mediated precipitation and peloids formed by in-situ chemically oscillating reactions,indicating a biochemical and chemical enrichment of phosphorus to sediments during the Early Ediacaran *** Upper Phosphorite Bed is mainly composed of carbonaceous,massive,and stromatolitic phosphorites,contains bioclasts(phosphatized spheroidal fossils),and intraclasts formed by hydrodynamic agitation,suggesting that the major accesses of phosphorus to sediments were the remineralization of organic *** of the two economic phosphorite beds was controlled by two sea-level *** differences have also been documented in contemporaneous phosphate-bearing successions in Brazil and Mangolia,indicating a significant shift in global phosphogenic mechanism during the early and middle Ediacaran,which may be due to the changes in redox conditions in seawater,associated with the Neoproterozoic Oxygenation *** regional active P-cycle processes could produce more free oxygen,which may have contributed to the up

关键词： phosphorite lithofacies phosphatic grains phosphogenic paragenesis phosphorus cycle mineralogy

Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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science China(Information sciences) 2024年第6期67卷 342-358页

作者： Jun CAO Jian jiao Hao LIU Rongxing LU Qinyu ZHANG Guangdong Provincial Key Laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer science (FCs) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. specifically, we utilize the sun-Mars and sun-saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection