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Synthesis of Two Coumarins Isolated from Aster praealtus

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Chinese Journal of Chemistry 2015年第7期33卷 723-728页

作者： bo Wang huijun Chen Yikang Wu bo Liu State Key Laboratory of Bioorganic and Natural Products Chemistry Collaborative Innovation Center of Chemistry for Life Sciences Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China Key Laboratory of Green Chemical Technology of College of heilongjiang Province School of Chemical and Environmental Engineering Harbin University of Science and Technology Harbin 150040 China

Two coumarins isolated from Aster praealtus were synthesized via a direct coupling of the corresponding cyclohexyl carbinol with a coumarin-derived aryl bromide or iodide, a very difficult etherification due to the excess steric congestion around the carbinol and the low reactivity of the aryl halide that frustrated many seemingly feasible protocols. Unequivocal ^1h and ^13C NMR data for these compounds were thus made available for the first time. Uncertainty and errors in ^1h and ^13C NMR data in previous reports are also eliminated and revealed, respectively.

关键词： alcohols condensation natural products stereochemistry ethers

Mesoporous silica anchored on reduced graphene oxide nanocomposite as anode for superior lithium-ion capacitor

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Rare Metals 2022年第2期41卷 368-377页

作者： Sherif A.El-Khodary Gokila Subburam bo-bo Zou Juan Wang Jing-Xia Qiu Xian-hu Liu Dickon h.L.Ng Shuang Wang Jia-Biao Lian School of Energy and Power Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013China Building Physics and Environment Institute Housing and Building National Research Center(HBRC)Dokki 12311CairoEgypt School of Energy and Power Engineering Institute for Energy ResearchSchool of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013China Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationZhengzhou UniversityZhengzhou 450002China Department of Physics The Chinese University of Hong KongShatinHong Kong 999077China School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China

Mesoporous silica(mSiO_(2))has attracted great interest as anode for lithium-ion ***,the low intrinsic conductivity is a major challenge for its *** this study,a low-cost sol–gel method is employed to synthesize mesoporous silica anchored on graphene nanosheets(rGO)for lithium *** results exhibit that the nanocomposite(mSiO_(2)@rGO)with high surface area(616.45 m^(2)·g^(–1))has chemical coupling bonds(Si–O–C)between SiO2 and rGO species,which would be favorable for lithium storage upon synergistic ***,the mSiO_(2)@rGO exhibits a high specific capacity of 1119.6 mAh·g^(–1)at 0.1 A·g^(–1)with outstanding cycling stability(92.5%retention over 1400 cycles at 1.0 A·g^(–1)).

关键词： lithium cycling synergistic

Theoretical Prediction of Differential Cross Sections for Reaction pp → pK^＋A in a Resonance Model

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Communications in Theoretical Physics 2006年第3X期46卷 501-506页

作者： LIU bo-Chao Institute of high Energy Physics the Chinese Academy of Sciences P.O. Box 918 (4) Beijing 100049 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 China Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

The reaction of pp → pK^＋A is a very good channel to study N^＊ resonances through their KA decay mode, because there is no mixing of isospin I = 1/2 and I = 3/2 due to isospin conservation. In this work, we extend a resonance model, which can reproduce the total cross section very well, to offer differential cross section information about this reaction. It can serve as a reference to build the scheduled hadron detector at Lanzhou Cooler Storage Ring （CSR）. Experiment measurement of these differential cross sections in the future will supply us more constraints on the model and help us understanding the strangeness production dynamics better.

关键词： resonance model pp collision

A Novel hydrogen-bonded Three-dimensional Network Complex Containing Nickel

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Chemical Research in Chinese Universities 2004年第2期20卷 127-130页

作者： WANGLi LIJuan WANGEn-bo InstituteofPolyoxometalateChemistry EacultyofChemistryNortheastNormalUniversityChangchun130024P.R.China

A novel complex, (h 3O) 2[Ni(2,6-pydc) 2]·2h 2O was synthesized in an aqueous solution and characterized by means of single-crystal X-ray diffraction, elemental analyses and IR spectra. The X-ray structural analysis revealed that the novel compound forms three-dimensional(3D) networks by both π-π stacking and hydrogen-bonding interactions. The crystal data for the complex are a=13.853(3) nm, b=9.6892(19) nm, c=13.732(3) nm, α=90.00°, β=115.52(3)°, γ=90.00°, Z=3, R 1=0.0786, wR 2=0.1522.

关键词： Stacking hydrogen-bonding interaction Three-dimensional(3D) network 2,6-Pyridinedicarboxylic acid

Dirichlet problem for Schrodinger equation with the boundary value in the BMO space

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Science China Mathematics 2022年第7期65卷 1431-1468页

作者： Renjin Jiang bo Li Center for Applied Mathematics Tianjin UniversityTianjin 300072China College of Data Science Jiaxing UniversityJiaxing 314001China

Let(X,d,μ)be a metric measure space satisfying a Q-doubling condition(Q>1)and an L^(2)-Poincaré*** L=L+V be a Schrödinger operator on X,where L is a non-negative operator generalized by a Dirichlet form,and V is a non-negative Muckenhoupt weight that satisfies a reverse hölder condition Rh_(q) for some q≥(Q+1)/*** show that a solution to(L−∂_(t)^(2))u=0 on X×R_(+) satisfies the Carleson condition,sup_(B(xB,rB))1/μ(B(xB,rB))∫_(0)^(rB)∫_(B(xB,rB))|t∇u(x,t)|^(2)dμdt/the Poisson integral of the Schrodinger operator L with the tracein the BMO(bounded mean oscillation)space associated with L.

关键词： Schrodinger equation BMO Carleson measure metric measure space

Nonexistence of the NNSC-cobordism of Bartnik data

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Science China Mathematics 2021年第7期64卷 1357-1372页

作者： bo Leyang Shi Yuguang Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China

In this paper,we consider the problem of the nonnegative scalar curvature(NNSC)-cobordism of Bartnik data(∑_(1)^(n-1),γ_(1),h_(1))and(∑_(2)^(n-1),γ_(2),h_(2)).We prove that given two metricsγ_(1)andγ_(2)on S^(n-1)(3≤n≤7)with h_(1)fixed,then(S^(n-1),γ_(1),h_(1))and(S^(n-1),γ_(2),h_(2))admit no NNSC-cobordism provided the prescribed mean curvature h2 is large enough(see Theorem 1.3).Moreover,we show that for n=3,a much weaker condition that the total mean curvature∫_(s^(2))h_(2)dpγ_(2)is large enough rules out NNSC-cobordisms(see Theorem 1.2);if we require the Gaussian curvature ofγ_(2)to be positive,we get a criterion for nonexistence of the trivial NNSCcobordism by using the hawking mass and the Brown-York mass(see Theorem 1.1).For the general topology case,we prove that(∑_(1)^(n-1),γ_(1),0)and(∑_(2)^(n-1),γ_(2),h_(2))admit no NNSC-cobordism provided the prescribed mean curvature h_(2)is large enough(see Theorem 1.5).

关键词： cobordism scalar curvature mean curvature

Some Physiological Responses of Chinese Iris to Salt Stress

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Pedosphere 2008年第4期18卷 454-463页

作者： BAI Wen-bo LI Pin-Fang LI Bao-Guo h. FUJIYAMA FAN Fen-Cheng College of Resources and Environmental Sciences China Agricultural University Key Laboratory of Plant-Soil Interactions Ministry of Education Beijing 100094 （China） Faculty of Agriculture Tottori University Tottori 680-8553 （Japan） Beijing Oasis Technology Development Co. Ltd. Beijing 100094 （China）

Chinese iris （Iris lactea Pall. var. chinensis （Fisch） Koidz.）, a robust iridaceous plant, is widespread in arid and semiarid regions with high salinity. however, the mechanism of its salt tolerance is not well understood. In this study, plant growth, water status, content and distribution of inorganic ions, cell membrane permeability, and proline content of I. laetea under salt stress were investigated using nutrient solutions with six NaCl concentrations ranging from 0 to 350 mmol L^-1. The results indicated that the biomass, height, fresh weight, K^＋ content, and K^＋/Na^＋ and Ca^2＋/Na^＋ ratios decreased with increasing NaCl stress, whereas plant water deficit and contents of Na^＋ and Cl- increased with increasing NaCl stress. In all salt treatments, water deficit of shoots was found to be higher than that of roots and had a positive correlation with salt concentration. When the NaCl concentration was less than 280 mmol L^-1, the ion absorption selectivity ratio and the transportation selectivity ratio sharply increased with increasing NaCl stress. Under medium salt stress, I. lactea exhibited a strong K^＋ selective absorption and the transportation of K^＋ from roots to shoots increased, whereas Na^＋ was not transported and was mostly retained in roots. The plants were able to maintain osmotic adjustment through the accumulation of Na^＋, Cl-, and proline. On the basis of its biomass production under salt stress, I. lactea could be considered as a facultative halophyte.

关键词： inorganic ion Iris lactea Pall. var. chinensis (Fisch) Koidz. NaCl stress osmotic adjustment

Interpretable machine learning analysis and automated modeling to simulate fluid-particle flows

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Particuology 2023年第9期80卷 42-52页

作者： bo Ouyang Litao Zhu Zhenghong Luo Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao TongUniversityShanghai200240China

The present study extracts human-understandable insights from machine learning(ML)-based mesoscale closure in fluid-particle flows via several novel data-driven analysis approaches,i.e.,maximal information coefficient(MIC),interpretable ML,and automated *** is previously shown that the solidvolume fraction has the greatest effect on the drag *** present study aims to quantitativelyinvestigate the influence of flow properties on mesoscale drag correction(h_(d)).The MIC results showstrong correlations between the features(i.e.,slip velocity(u^(*)_(sy))and particle volume fraction(εs))and thelabel h_(d).The interpretable ML analysis confirms this conclusion,and quantifies the contribution of u^(*)_(sy),εs and gas pressure gradient to the model as 71.9%,27.2%and 0.9%,*** ML without theneed to select the model structure and hyperparameters is used for modeling,improving the predictionaccuracy over our previous model(Zhu et al.,2020;Ouyang,Zhu,Su,&Luo,2021).

关键词： Filtered two-fluid model Fluid-particle flow Mesoscale closure Interpretable machine learning Automated machine learning Maximal information coefficient

Access to high-Molecular-Weight Polyethylenes through high Temperature Ethylene Polymerization Catalysed by Ethylene-Bridged ansa-(3-R-Cyclopentadienyl)(Fluorenyl) Zirconocene Complexes

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Chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： bo Li haiyan Ma Jiling huang Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of C1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(MAO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization high temperature