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Direct constraint on cosmic neutrino mass using observational Hubble parameter data

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Research in Astronomy and Astrophysics 2018年第10期18卷 75-84页

作者： hao-yi wan Shu-Lei Cao Huan-Yu Teng Yu Liu Jian-Chen Zhang Tong-Jie Zhang Department of Astronomy Beijing Normal UniversityBeijing 100875China Dezhou University Dezhou 253023China

In order to explore the properties of cosmic neutrinos, i.e. sum of the neutrino mass （∑mv） and the effective number of neutrino species （Neff）, which affects the Hubble expansion rate H（z） and the power of observational Hubble parameter data （OHD） in constraining cosmological parameters under the ACDM model, we utilize OHD to constrain the properties of cosmic neutrinos and apply an accurate H（z） function with ∑ mv, and Neff. First, we simulate new OHD beyond the existing 43 OHD. According to the predictions of measurements of Ho （the current H（z） value）, baryon acoustic oscillations （BAO） peaks, Sandage-Loeb （SL） test and cosmic microwave background （CMB）, we as-sume observational accuracy up to 2% and redshift 0 〈 z ~〈 5. With simulated H（z） data obtained from the fiducial model, we constrain the parameters including ∑ mv, and Neff. When all parameters are set free, ∑mv 〈 0.196eV （95%） and Neff = 2.984 ± 0.826 （68%） are obtained, and when fixing Neff as the standard baseline 3.046, we attain ∑ mv 〈 0.240 eV （95%）. These constrained results are much tighter than the ones obtained by the current OHD, which makes the prospect of OHD in constraining cosmological parameters more promising as its accuracy and quantity grow.

关键词： cosmological parameters - cosmology miscellaneous - methods data analysis

Performance evaluation of HY-2 series satellites in marine gravity field recovery

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Geodesy and Geodynamics 2024年第4期15卷 397-403页

作者： Ruijie hao Xiaoyun wan Keyan Zhang School of Land Science and Technology China University of Geosciences(Beijing)Beijing100083China School of Geospatial Engineering and Science Sun Yat-Sen UniversityZhuhai519082China

China has successfully launched four Haiyang-2(HY-2)series altimetry ***-2A has attracted significant attention in gravity field recovery,but the performance of other HY-2 series satellites,including HY-2B/C/D,is seldom *** study evaluated the performance of all the HY-2 series satellites in recovering marine gravity ***,the crossover discrepancies in sea surface height of the four satellites,HY-2A,HY-2B,HY-2C,and HY-2D,were analyzed to assess their altimetry *** was found that HY-2B had the best altimetry quality,followed by ***,different combina-tions of altimetry data were used to calculate vertical deflections and gravity anomalies in the South China Sea(112°E-119°E,12°N-20°N).The results showed that combining data from HY-2B,HY-2C,and HY-2D improved the inversion accuracy of gravity anomalies by 0.3 mGal compared to using HY-2A data ***-2C and HY-2D contributed to enhancing the accuracy of the east component of vertical deflections.

关键词： Satellite altimetry HY-2 Sea surfaceheight Marinegravityfield

Palladium single atoms from melting nanoparticles on WO_(3-x) for boosted hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第4期91卷 637-644页

作者： Zhongmiao Gong Zhigang Chen hao Li Guang Yang Min Yuan Zhiyun Li Xueying wan yi Cui School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026AnhuiChina i-lab Vacuum Interconnected Nanotech WorkstationSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina School of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China Key Laboratory of Precision and Intelligent Chemistry School of Chemistry and Materials ScienceHefei National Research Center for Physical Sciences at the MicroscaleNational Synchrotron Radiation LaboratorySchool of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

Surface-supported isolated atoms in single-atom catalysts(SACs)grant maximum utilization of metals in heterogeneous ***,we report a feasible pyrolysis strategy to synthesize Pd single atoms by thermally melting Pd nanoparticles on an oxygen-vacancy-rich tungsten-oxide matrix at reduction *** ambient pressure X-ray photoelectron spectroscopy was used to monitor the formation of zero-valence Pd single atoms and the increased metallic feature of WO_(3-x)***,the as-obtained zero-valence Pd single-atom catalyst exhibits a markedly boosted HER activity with a low overpotential(η_(10)=70 mV)at the current density of 10 mA/cm2and a small Tafel slope(b=68 mV/dec),nearly 150 mV and a 3,0-fold enhancement than those of Pd nanoparticles(η_(10)=220 mV,b=133 mV/dec)under the same *** addition,quasi in situ XPS results suggest the hydrogen spillover effect is more likely to occur on Pd single atoms during the electrochemical *** work may pave an interesting route for the rational design of highly-efficient single-atom catalysts,and the elucidation of corresponding enhanced reaction mechanisms by the utilization of advanced characterization techniques.

关键词： Pd WO_(3-x) Single-atom catalysts NAP-XPS HER

Coarse-fine joint target parameter estimation method based on AN-RSC in OFDM passive radar

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Journal of Systems Engineering and Electronics 2024年第2期35卷 339-349页

作者： wanG Chujun wan Xianrong yi Jianxin CHENG Feng School of Electronic Information Wuhan UniversityWuhan 430072China

In this paper,we study the accuracy of delay-Doppler parameter estimation of targets in a passive radar using orthogonal frequency division multiplexing(OFDM)signal.A coarse-fine joint estimation method is proposed to achieve better estimation accuracy of target parameters without excessive computational ***,the modulation symbol domain(MSD)method is used to roughly estimate the delay and Doppler of ***,to obtain high-precision Doppler estimation,the atomic norm(AN)based on the multiple measurement vectors(MMV)model(MMV-AN)is used to manifest the signal sparsity in the continuous Doppler *** the same time,a reference signal compensation(RSC)method is presented to obtain highprecision delay *** results based on the OFDM signal show that the coarse-fine joint estimation method based on AN-RSC can obtain a more accurate estimation of target parameters compared with other *** addition,the proposed method also possesses computational advantages compared with the joint parameter estimation.

关键词： passive radar orthogonal frequency division multiplexing(OFDM)signal atomic norm(AN) parameter estimation

Synthesis of Diverse Oxetane Amino Acids via Visible-Light-Induced Photocatalytic Decarboxylative Giese-Type Reaction

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Chinese Journal of Chemistry 2024年第12期42卷 1341-1346页

作者： haoliang Shi yi wan Yongqiang Zhang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism Shanghai Key Laboratory of New Drug Designand School of PharmacyEast China University of Science and TechnologyShanghai200237 China

The divergent synthesis of versatile 3,3′-disubstituted oxetane amino acids by utilizing visible-light-induced photocatalytic decarboxylative Giese-type reaction has been demonstrated.3-Methyleneoxetane-derived substrates are readily available in a single-step and highly reactive as radical acceptors,allowing the production of versatile oxetaneγ-andα-amino acids in high yields.A distinct ring strain release-driven radical addition mechanism was preliminarily *** preparative power was further highlighted by the application in the synthesis of oxetane-containing dipeptides and azetidine amino acids,as well as the transformation of the product into novel oxetane-containing spiro-heterocycle pharmacophore.

关键词： Photoredox catalysis Decarboxylative Giese-type reaction Oxetane amino acids Amino acids Synthesis Radical reactions

Strong Interaction Between Redox Mediators and Defect-Rich Carbons Enabling Simultaneously Boosted Voltage Windows and Capacitance for Aqueous Supercapacitors

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Energy & Environmental Materials 2024年第4期7卷 269-276页

作者： Lu Guan yifan Zhu yi wan Mengdi Zhang Qiang Li Xiaoling Teng Yunlong Zhang hao Yang Yan Zhang Han Hu Mingbo Wu State Key Laboratory of Heavy Oil Processing College of Chemical Engineering China University of Petroleum (East China) College of Physics University-Industry Joint Center for Ocean Observation and Broadband Communication Qingdao University

Energy density,the Achilles'heel of aqueous supercapacitors,is simultaneously determined by the voltage window and specific capacitance of the carbon materials,but the strategy of synchronously boosting them has rarel... 详细信息

关键词： defect-rich carbons redox mediators strong interaction supercapacitors voltage windows

Selective oxidation using in-situ generated hydrogen peroxide over titanosilicates

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结构化学 2024年第6期43卷 12-14页

作者： Zhipeng wan hao Xu Peng Wu State Key Laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal UniversityShanghai200062China State Key Laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal UniversityShanghai200062China Institute of Eco-Chongming Shanghai202162China

Titanosilicates are a class of heteroatom-containing zeolitic materials with tetrahedrally coordinated Ti4+ions incorporated into crystalline zeolite frameworks,with TS-1,Ti-MWW and Ti-MOR as representative and attractive selective oxidation *** liquid-phase oxidations of a variety of substrates such as olefins and ketones with the green oxidant of H2O2 over titanosilicates under mild conditions have attracted considerable research interests in the clean production of fine and bulk chemicals,among which propylene epoxidation and cyclohexanone ammoximation have been industrialized[1].

关键词： PHASE EPOXIDATION PROPYLENE H-2

Preparation and properties of ZrO_(2)-strengthened porous mullite insulation materials using Y_(2)O_(3) additive

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Journal of Iron and Steel Research International 2024年第6期31卷 1514-1521页

作者： wang-zhi Yu yi-hong Shi Ping Liu Yong-wan Wu Cheng-hao Song Xian-gong Deng Xiang Ding Song-lin Ran yi Zhang Hai-jun Zhang Hai-liang Deng Advanced Ceramics Research Center School of Materials Science and EngineeringAnhui University of TechnologyMa'anshan 243002AnhuiChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

ZrO_(2)-strengthened porous mullite insulation materials were prepared by foaming technology utilizing ZrSiO_(4) and Al_(2)O_(3) as primary materials and Y_(2)O_(3) as an *** effects of Y_(2)O_(3) contents on the phase composition,microstructure,mechanical properties,and heat conductivity of the porous mullite insulation materials were investigated.A suitable Y_(2)O_(3) content could promote phase transition of monoclinic ZrO_(2)(m-ZrO_(2))to tetragonal ZrO_(2)(t-ZrO_(2)),reduce pore size,and improve the strengths of as-prepared *** cold crushing strength and bending strength of as-prepared specimens with a 119µm spherical pore size using 6 wt.%Y_(2)O_(3) were 35.2 and 13.0 MPa,respectively,with a heat conductivity being only 0.248 W/(m K).

关键词： Porous mullite insulation material Zirconium oxide Y_(2)O_(3) Mechanical property Heat conductivity

Acyclic Edge Coloring of 1-planar Graphs without 4-cycles

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 35-44页

作者： Wei-fan wang yi-qiao wang wan-shun Yang Department of Mathematics Zhejiang Normal UniversityJinhua321004China School of Management Beijing University of Chinese MedicineBeijing100029China School of Mathematics and Information Science Weifang UniversityWeifang261061China

An acyclic edge coloring of a graph G is a proper edge coloring such that there are no bichromatic cycles in *** acyclic chromatic index χ'α(G) of G is the smallest k such that G has an acyclic edge coloring using k *** was conjectured that every simple graph G with maximum degree Δ has χ'_α(G) ≤Δ+2.A1-planar graph is a graph that can be drawn in the plane so that each edge is crossed by at most one other *** this paper,we show that every 1-planar graph G without 4-cycles has χ'_α(G)≤Δ+22.

关键词： 1-planar graph acyclic edge coloring acyclic chromatic index