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Forecasts of cosmological constraints from HI intensity mapping with FAST,BINGO and SKA-I

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Research in Astronomy and Astrophysics 2019年第12期19卷 343-360页

作者： Elimboto Yohana yi-chao li yin-Zhe Ma Astrophysics and Cosmology Research Unit School of MathematicsStatistics&Computer ScienceUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa Dar Es Salaam University College of Education A Constituent College of the University of Dar Es SalaamP.O.Box 2329 Dar Es SalaamTanzania Astrophysics and Cosmology Research Unit School of Chemistry and PhysicsUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa NAOC-UKZN Computational Astrophysics Centre(NUCAC) University of KwaZulu-NatalDurban4000South Africa

We forecast the cosmological constraints of the neutral hydrogen(HI) intensity mapping(IM)technique with radio telescopes by assuming 1-year of observational time. The current and future radio telescopes that we consider here are Five-hundred-meter Aperture Spherical radio Telescope(FAST), Baryon acoustic oscillations In Neutral Gas Observations(BINGO), and Square Kilometre Array phase Ⅰ(SKA-Ⅰ) single-dish experiments. We also forecast the combined constraints of the three radio telescopes with Planck. We find that the 1σ errors of(w0, wa) for BINGO, FAST and SKA-Ⅰ with respect to the fiducial values are respectively,(0.9293, 3.5792),(0.4083, 1.5878) and(0.3158, 0.4622). This is equivalent to(56.04%, 55.64%) and(66.02%, 87.09%) improvements in constraining(w0, wa) for FAST and SKA-Ⅰ respectively relative to BINGO. Simulations further show that SKA-Ⅰ will put more stringent constraints than both FAST and BINGO when each of the experiments is combined with Planck measurements. The 1σ errors for(w0, wa), BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck covariance matrices are respectively(0.0832, 0.3520),(0.0791, 0.3313) and(0.0678, 0.2679) implying there is an improvement in(w0, wa) constraints of(4.93%, 5.88%) for FAST + Planck relative to BINGO + Planck and an improvement of(18.51%, 23.89%) in constraining(w0, wa) for SKA-Ⅰ + Planck relative to BINGO + Planck. We also compared the performance of Planck data plus each single-dish experiment relative to Planck alone,and find that the reduction in(w0, wa) 1σ errors for each experiment plus Planck, respectively, imply the(w0, wa) constraints improvement of(22.96%, 8.45%),(26.76%, 13.84%) and(37.22%, 30.33%) for BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck relative to Planck alone. For the nine cosmological parameters in consideration, we find that there is a trade-off between SKA-Ⅰ and FAST in constraining cosmological parameters, with each experiment being more superior in constraining a particular set of parameter

关键词： surveys galaxies:statistics cosmology:observations large-scale structure of Universe galaxies:kinematics and dynamics

Cosmological constraint on Brans-Dicke Model

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Research in Astronomy and Astrophysics 2015年第12期15卷 2151-2163页

作者： Ji-Xia li Feng-Quan Wu yi-chao li Yan Gong Xue-Lei Chen National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Center of High Energy Physics Peking University

We combine new Cosmic Microwave Background （CMB） data from Planck with Baryon Acoustic Oscillation （BAO） data to constrain the Brans-Dicke （BD） the- ory, in which the gravitational constant G evolves with time. Observations of type Ia supernovae （SNela） provide another important set of cosmological data, as they may be regarded as standard candles after some empirical corrections. However, in theories that include modified gravity like the BD theory, there is some risk and complication when using the SNIa data because their luminosity may depend on G. In this paper, we assume a power law relation between the SNIa luminosity and G, but treat the power index as a free parameter. We then test whether the differ- ence in distances measured with SNIa data and BAO data can be reduced in such a model. We also constrain the BD theory and cosmological parameters by making a global fit with the CMB, BAO and SNIa data set. For the CMB＋BAO＋SNIa data set, we find 0.08 × 10-2 〈 ζ 〈 0.33 ×10-2 at the 68% confidence level （CL） and -0.01 × 10-2 〈 ζ〈 0.43 × 10-2 at the 95% CL, where ζ is related to the BD parameter w by ζ = In（1 ＋ 1/w）.

关键词： cosmology: supernovae -- Brans-Dicke -- standard-candle -- BAO

Scale-free brain ensemble modulated by phase synchronization

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第10期15卷 821-831页

作者： Dan WU chao-yi li Jie liU Jing LU De-zhong YAO Department of Biomedical Engineering School of Computer and Information TechnologyBeijing Jiaotong University NeuroInformation of Ministry of Education University of Electronic Science and Technology of China

To listen to brain activity as a piece of music, we proposed the scale-free brainwave music(SFBM) technology, which could translate the scalp electroencephalogram(EEG) into music notes according to the power law of both EEG and music. In the current study, this methodology was further extended to a musical ensemble of two channels. First, EEG data from two selected channels are translated into musical instrument digital interface(MIDI) sequences, where the EEG parameters modulate the pitch, duration, and volume of each musical note. The phase synchronization index of the two channels is computed by a Hilbert transform. Then the two MIDI sequences are integrated into a chorus according to the phase synchronization index. The EEG with a high synchronization index is represented by more consonant musical intervals, while the low index is expressed by inconsonant musical intervals. The brain ensemble derived from real EEG segments illustrates differences in harmony and pitch distribution during the eyes-closed and eyes-open states. Furthermore, the scale-free phenomena exist in the brainwave ensemble. Therefore, the scale-free brain ensemble modulated by phase synchronization is a new attempt to express the EEG through an auditory and musical way, and it can be used for EEG monitoring and bio-feedback.

关键词： Brainwave Ensemble Music Scale-free Synchronization

Well-dispersed Sb particles embedded on N-doped carbon nanofibers toward high-performance li-ion battery

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Rare Metals 2024年第7期43卷 2994-3006页

作者： ying li yi-Han Zhao Lu-Lu Zhao Peng-Fei Wang ying Xie Ting-Feng yi School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004China Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China

The alloy-type material Sb is widely used in the anode materials of lithium-ion batteries(liBs)due to its high theoretical specific ***,its serious volume expansion problem during alloying/dealloying of li~+limits its practical *** this work,C-Sb composite was constructed as anode material of liBs by electrospinning route for the first time,Sb was introduced into the polyacrylonitrile-based hard carbon and coal tar pitch-based soft carbon composite amorphous carbon fiber with a diameter of 300-600 nm,which realized high cycling *** C-Sb-2(the mass ratio of polyacrylonitrile to Sb source is 1:2)electrode displayed charge capacities of 1098.5,930.3,841.7,753.5,643.9 and 545.8 mAh·g^(-1)at 0.1,0.2,0.3,0.5,1 and 2 A·g^(-1),*** when the current density returned to 0.1 A·g^(-1),the charge capacity was 939.3 mAh·g^(-1),revealing good stability and *** introduction of Sb into the amorphous carbon improved its conductivity and addressed the volume expansion issue of high specific capacity Sb during charge/***-situ XRD analysis confirmed the high reversibility of the C-Sb-2 during charging and *** functional theory(DFT)calculations revealed the gradual enhancement of the interface interaction between Sb_(x)li_(y) and amorphous carbon(AMC)with increasing lithium content,contributing to the anchoring of alloy nanoparticles on the AMC surface and buffering the volume change of the ***,the gradual lithiation of Sb facilitated the electron transfer from Sb_(x)li_(y) to *** findings hold promise for designing lithium storage materials with exceptional performance,highlighting the potential of C-Sb composites as anode materials for efficient next-generation lithium storage.

关键词： li-ion battery Metallic Sb Carbon Electrospinning Cycling stability

Enhanced Electrochemical Properties and Optimized li+ Transmission Pathways of PEO/LLZTO-Based Composite Electrolytes Modified by Supramolecular Combination

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Energy & Environmental Materials 2024年第1期7卷 242-250页

作者： Zhengyi Lu lin Peng yi Rong Enli Wang Ruhua Shi Hongxun Yang Yadong Xu Ruizhi Yang chao Jin College of Energy Soochow Institute for Energy and Materials InnovationsSoochow University Jiangsu Runchao Energy Storage Technology Co. Ltd

Poly（ethylene oxide）(PEO) and li6.75La3Zr1.75Ta0.25O12（LLZTO）-based composite polymer electrolytes（CPEs） are considered one of the most promising solid electrolyte ***,agglomeration of LLZTO within PEO and lack ... 详细信息

关键词： conductivity interfacial stability LLZTO fillers modification PEO matrix

Sky reconstruction for the Tianlai cylinder array

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Research in Astronomy and Astrophysics 2016年第10期16卷 71-80页

作者： Jiao Zhang Shi-Fan Zuo Reza Ansari Xuelei Chen yi-chao li Feng-Quan Wu Jean-Eric Campagne Christophe Magneville Key Laboratory of Computational Astrophysics National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China Universite Paris-Sud LALUMR 8607F-91898 Orsay CedexFrance&CNRS/IN2P3F-91405 OrsayFrance University of Chinese Academy of Sciences Beijing 100049China Center for High Energy Physics Peking UniversityBeijing 100871China CEA DSM/IRFUCentre d'Etudes de SaclayF-91191 Gif-sur-YvetteFrance

We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylin- der array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer func- tion and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configura- tions.

关键词： cosmology: observation -- HI intensity mapping -- method: transit telescope -- map making

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

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Journal of Integrative Agriculture 2024年第1期23卷 187-194页

作者： Qi Zhang Wenqin Zhan chao li ling Chang yi Dong Jiang Zhang State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhan 430062China Oil Crops Research Institute Chinese Academy of Agricultural SciencesWuhan 430062China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518000China

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect *** green peach aphid,Myzus persicae,feeds on over 400 species of host *** napus(rape)is the second most important oilseed crop *** persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life *** this study,we tested the RNAi effects of transgenic rape plants on *** in vitro feeding *** with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi ***-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of *** next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic *** to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to *** assays revealed that feeding transgenic rape plants to *** significantly decreased MpPar6 expression and survival rate and impaired ***,we showed that the resistance levels to *** are positively correlated with ds Par6 expression levels in transgenic rape *** study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from *** with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

关键词： oilseed rape pest control aphid double-stranded RNA RNA interference

Structural Evolution of Ultra-High Molecular Weight Polyethylene Low-Entangled Films with Reserved Shish Crystals During Hot Stretching

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Chinese Journal of Polymer Science 2024年第8期42卷 1227-1242页

作者： Jia-Wei Gao li Chen Ye-Shun Zhong chao-Wei Xing yi-Guo li Zong-Bao Wang School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China

Shish crystals are crucial to achieving high performance low-dimensional ultra-high molecular weight polyethylene(UHMWPE)***,high stretch and shear flow fields are necessary for the formation of shish *** this study,UHMWPE gel films with reserved shish crystals were prepared by gel molding,the structural evolution and properties of UHMWPE films stretched at temperatu res of 100,110,120and 130℃were investigated by in situ small-angle X-ray scattering(SAXS)/ultra-small-angle X-ray scattering(USAXS)/wide-angle X-ray diffraction(WAXD)measu rements as well as scanning electron microscopy(SEM)and differential scanning calorimetry(DSC)*** findings showed that the reserved shish crystals can facilitate the formation and structural evolution of shish-kebab crystals during the hot ***,the reserved shish crystals promote the structu ral evolution of UHMWPE films to a greater extent when stretched at 120 and 130℃,compared to 100 and 110℃,resulting in higher crystallinity,orientation,thermal properties,breaking strength and Young's *** pared to UHMWPE high-entangled films with reserved shish crystals prepared by compression molding,UHMWPE low-entangled films with reserved shish crystals prepared by gel molding are more effective in inducing the formation and evolution of shish-kebab crystals during the hot stretching,resulting in increased breaking strength and Young's modulus.

关键词： UHMWPE low-entangled films Reserved shish crystals Structural evolution Hot stretching

Physiological and Biochemical Responses of Perennial Ryegrass Mixed Planting with Legumes under Heavy Metal Pollution

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1749-1765页

作者： yi Xi li Zhang Yanhong Xu Wei Cheng chao Chen College of Animal Science Guizhou UniversityGuiyang550025China

In artiﬁcially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg·kg^(-1),respectively)to simulate compound pollution *** results showed that the concentrations of heavy metals,trans-port factors,and bioconcentration factors in mixed planting of ryegrass decreased compared with those in *** of whether heavy metal pollution was introduced,mixed planting increased the aboveground and underground biomasses of *** different mixed planting treatments had no signiﬁcant impact on the chlorophyll concentration of *** mowing time,mixed planting treatment,and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances,and there were some *** mixed planting treatment did not signiﬁcantly affect glutathione concentration,cysteine concentration,or nonprotein *** planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon,nitrogen,and *** results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal ***,it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.

关键词： Perennial ryegrass mixed planting phytoremediation lead zinc and cadmium soil pollution