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Science China Earth Sciences 2017年第2期60卷 315-327页

作者： yue jian MENG ZhiYong Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beij'ing 100871 China

This study explores for the first time the impact of assimilating radial velocity(Vr)observations from a single or multiple Taiwan's coastal radars on tropical cyclone(TC)forecasting after landfall in the Chinese mainland by using a Weather Research and Forecasting model(WRF)-based ensemble Kalman filter(EnKF)data assimilation *** Morakot(2009),which caused widespread damage in the southeastern coastal regions of the mainland after devastating Taiwan,was chosen as a case *** results showed that assimilating Taiwan's radar Vr data improved environmental field and steering flow and produced a more realistic TC position and structure in the final EnKF cycling ***,the subsequent TC track and rainfall forecasts in southeastern China were *** addition,better observations of the TC inner core by Taiwan's radar was a primary factor in improving TC rainfall forecast in the Chinese mainland.

关键词： Radial velocity EnKF TC track forecast Rainfall forecast Chinese mainland

Natural products are the treasure pool for antimalarial agents

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National Science Review 2022年第11期9卷 11-13页

作者： Bin Zhou jian-Min yue State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences

The history of mankind is a constant struggle against diseases, and humans have learned to use natural sources as the remedies to alleviate and/or treat diseases since prehistoric times.e structural diversity and complexity of molecules originated from natural sources are far beyond the scope of human creativity and imagination.

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Attractive natural products with strained cyclopropane and/or cyclobutane ring systems

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Science China Chemistry 2016年第9期59卷 1126-1141页

作者： Yao-yue Fan Xin-Hua Gao jian-Min yue Shanghai Institute of Materia Medica Chinese Academy of Sciences

The strained cyclopropane and/or cyclobutane subunits occurred in many complex natural products including terpenoids, steroids and alkaloids. Natural products with cyclopropane and/or cyclobutane motifs not only furnished fascinating structures, but also exhibited versatile biological activities, such as cytotoxic, anti-HIM antimicrobial, antiviral, and immunosuppressive effects. This review covered a large array of structurally unique natural products with strained cyclopropane and/or cyclobutane motifs and summarized their structural features, distributions, biological activities, as well as biogenetic considerations.

关键词： natural products cyclopropane-containing cyclobutane-containing biological activity biosynthetic pathway

The Maximum Lagrangian of 5-uniform Hypergraphs without Containing Two Edges Intersecting at a Vertex

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Acta Mathematica Sinica,English Series 2022年第5期38卷 877-889页

作者： Biao WU yue jian PENG MOE-LCSM School of Mathematics and StatisticsHu’nan Normal UniversityChangsha 410081P.R.China School of Mathematics Hu’nan UniversityChangsha 410082P.R.China

Obtaining Turán densities of hypergraph through determining Lagrangian densities have been studied *** showed that the Lagrangian density of an r-uniform hypergraph equals the Turán density of the extension of this ***,Lagrangian density and Turán density are the same for a large class of hypergraphs such as hypergraphs covering *** Pr,sbe the r-uniform hypergraph with two edges intersecting at s *** determined the Lagrangian densities of Pr,sfor r=3 and s=1 or 2,or r=4 and s=2 or *** and Keevash determined for r=3 and s=0,and Bene Watts,Norin and Yepremyan determined for r≥4 and s=*** cases r=5 and s=4 or r=6 and s=5 were determined by Norin and *** showed for r=5,6 or 7,and s=3,4 or 5 *** cases r=4 and s=1 or r=5 and s=2 were determined by jiang,Peng and Wu,and Hu,Peng and Wu *** r=5,the only remaining case is s=*** this paper,we determine for this case.

关键词： Hypergraph Lagrangian Turán number

Multicolored Bipartite Ramsey Numbers of Large Cycles

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 347-357页

作者： Shao-qiang LIU yue-jian PENG College of Mathematics and Statistics Hanshan Normal UniversityChaozhou 521041China School of Mathematics Hunan UniversityChangsha 410082China

For an integer r≥2 and bipartite graphs Hi,where 1≤i≤r,the bipartite Ramsey number br(H1,H2,…,Hr)is the minimum integer N such that any r-edge coloring of the complete bipartite graph KN;N contains a monochromatic subgraph isomorphic to Hi in color i for some 1≤i≤*** show that if r≥3;α1,α2>0,αj+2≥[(j+2)!-1]Σi=1^(j+1)α1 for j=1,2…r-2,then br(C2[α1n],C2[α2n],…,C2[αrn]=(Σ=j=1^(r)a j+o(1))n.

关键词： ramsey number bipartite ramsey number regularity lemma

Connection Between Continuous Optimization and Turán Densities of Non-uniform Hypergraphs

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Acta Mathematicae Applicatae Sinica 2021年第4期37卷 858-866页

作者： Xiao-bing GUO yue-jian PENG School of Mathematics Hunan UniversityChangsha410082China

A classical result of Motzkin and Straus established the connection between the Lagrangian of a graph and its maximum *** it,they gave a new proof of Turán’s *** aroused the interests in studying the connection between continuous optimization and extremal problems in *** 2009,*** Bulòand *** extended the result of Motzkin-Straus to r-uniform ***,Johnston and Lu initiated the study of the Turán density of a non-uniform *** optimization problems related to several types of non-uniform hypergraphs and its applications on Turán densities have also been *** this paper,we obtain a Motzkin-Straus type of results for all non-uniform *** it,we give an upper bound of the Turán density of a complete non-uniform hypergraph.

关键词： hypergrapli maximum clique polynomial optimization

Frontier studies on natural products:moving toward paradigm shifts

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Science China Chemistry 2023年第4期66卷 928-942页

作者： Jin-Xin Zhao jian-Min yue State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China Shandong Laboratory of Yantai Drug Discovery Bohai Rim Advanced Research Institute for Drug DiscoveryYantai 264117China

1 Introduction Natural products(NPs)historically serve as a valuable and productive source of bioactive compounds for drug *** discovery of a range of alkaloids in the early1800s,including strychnine,morphine,etc.,her... 详细信息

关键词： alkaloids moving compounds

Maximum Cliques of Hypergraphs and Polynomial Optimization

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Acta Mathematicae Applicatae Sinica 2018年第4期34卷 842-855页

作者： Yan-ming CHANG yue-jian PENG College of Mathematics Hunan University Changsha 410082 China Institute of Mathematics Hunan University Changsha 410082 China

A remarkable connection between the clique number and the Lagrangian of a graph was established by Motzkin and Straus. Later, Rota Bul′o and Pelillo extended the theorem of Motzkin-Straus to r-uniform hypergraphs by studying the relation of local（global） minimizers of a homogeneous polynomial function of degree r and the maximal（maximum） cliques of an r-uniform hypergraph. In this paper, we study polynomial optimization problems for non-uniform hypergraphs with four different types of edges and apply it to get an upper bound of Tur′an densities of complete non-uniform hypergraphs.

关键词： hypergraph maximum clique polynomial optimization

Synthesis, Characterization, and Fluorescence Sensor Property of Polyurethane/Ag2S Nanostrips

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Chinese Journal of Chemical Physics 2015年第6期28卷 -页

作者： Shan Wang Yi Huang jian-she yue School of Chemistry and Chemical Engineering of Xianyang Normal University Xianyang 712000 China

A polyurethane/silver sulfide nanocomposite film was synthesized by a biomineralization simulated method. The effect of the Ag2S nanoparticles on the physical properties of the composite was studied by Fourier transform infrared, differential scanning calorimetry (DSC), scanning electron microscopy. The thermal stability of the composite was measured by DSC. The fluorescence emission of the nanocomposite films was found to be very sensitive to Ni(II) ions, with a small amount of Ni(II) ions making the emissions increase dramatically. The films are predicted to have the potential to be developed into excellent sensing films of Ni(II) ions in the water.

关键词： Polyurethane Ag2S nanostrip Fluorescence sensor Ni(Ⅱ) ion sensor

A 2-step GPS carrier tracking loop for urban vehicle applications

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Journal of Systems Engineering and Electronics 2017年第5期28卷 817-826页

作者： Hongyang Zhang Luping Xu yue jian Xiaochen Ma School of Aerospace Science and Technology Xidian University Xi'an Flight Automatic Control Research Institute Aviation Industry Corporation of China Xi'an Aeronautics Computing Technique Research Institute Aviation Industry Corporation of China

Global positioning system (GPS) for vehicle applications in the urban area is challenged by low signal intensity. The carrier loop based on fast Fourier transform (FFT) can obtain a high signal to noise ratio (SNR) gain by increasing the observation time. However, this leads to a major problem that the acceleration cannot be ignored. The performance of the FFT-based loop will decline with the acceleration increasing. This paper discusses the effect of the dynamic on FFT first. Then a high performance carrier tracking loop for weak GPS L5 signals is proposed. It combines discrete chirp-Fourier transform (DCFT) and the phase fitting method to estimate Doppler frequency and Doppler rate simultaneously. First, a sequence of integration results is used to perform DCFT to estimate coarse Doppler frequency and Doppler rate. Second, the phase of the sequence is calculated and used to perform linear fitting. By the phase fitting method, the fine Doppler frequency and Doppler rate can be estimated. The computation cost is small because the integration results are used and the phase fitting method needs only coarse estimates of Doppler frequency and Doppler rate. Compared with FFT and DCFT, the precision of the phase fitting method is not limited by the resolution. Thus the proposed loop can get high precision and low carrier to noise ratio (C/N-0) tracking threshold. Simulation results show this loop has a great improvement than conventional loops for urban weak-signal applications.

关键词： satellite navigation receiver signal processing frequency lock loop