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Effect of valence and spin state on ethane dehydrogenation in Fe-S-1 catalyst

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Journal of Energy Chemistry 2024年第10期97卷 677-686页

作者： Liusai Huang Yumeng Fo Peng Zhang Shaojia song x.nx.n Zhang xueqiu Wu Saeed Soltanali jian Liu Weiyu song State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) China Petrochemical Research Institute PetroChina Company Limited Catalysis Technologies Development Division Research Institute of Petroleum Industry (RIPI)

Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins *** alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined *** valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,CxHy...Mδ+...H) during the C-H bond cleavage process,which in turn affects the catalytic ***,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical ***（Ⅱ）-S-1 and Fe（Ⅲ）-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C2H6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe（Ⅱ）-S-1,Under the same evaluation co nditio n,Fe（Ⅱ）-S-1 exhibits a higher space time yield of *** functional theory（DFT） results reveal that the more coordinate-unsaturated and electron-enriched Fe（Ⅱ） sites boost the first C-H bond activation by slight deformation and efficient electron donation with C2H5****,the second C-H bond cleavage on Fe（Ⅱ）-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of *** analysis is consistent with the experimental and DFT *** work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.

关键词： DFT Electron-enriched Ethane dehydrogenation Iron Spin crossover

On the Quantum Cohomology of Blow-ups of Four-dimensional Quadrics

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Acta Mathematica Sinica,English Series 2024年第1期40卷 313-328页

作者： jian x.n HU Hua Zhong KE Chang Zheng LI Lei song School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

We propose a conjecture relevant to Galkin’s lower bound conjecture,and verify it for the blow-ups of a four-dimensional quadric at a point or along a projective *** also show that Conjecture O holds in these two cases.

关键词： Quantum cohomology blow-up quadric hypersurface

Catalytic behavior of Mo-Bi-Fe-Co-K-M-O(M=Ce,Gd,CeGd)catalysts for selective oxidation of isobutene

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Journal of Rare Earths 2024年第1期42卷 84-93,I0003页

作者： Qinghui Li Huahua Zhao jian Yang Jun Zhao Liang Yan Huanling song Lingjun Chou State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China

The further improvement of methacrolein(MAL)selectivity from isobutene(IB)oxidation is crucial and *** this study,based on the typical Mo-Bi-Fe-Co-K-O mixed metal oxide,the rare earth element Gd-doped,Ce-doped and CeGd co-doped catalysts were prepared by co-precipitation strategy to increase the selectivity of MAL from 47.9%to 49.8%,64.2% and 68.6%,*** order to elucidate in-depth the promoting effect of Ce and/or Gd,various characterizations were utilized including x-ray diffraction patterns(xRD),Raman,x-ray fluorescence spectrometry(xRF),x-ray photoelectron spectroscopy(xPS),O_(2)-temperature programmed desorption(O_(2)-TPD),H2-temperature programmed reduction(H2-TPR),CO_(2)-temperature programmed desorption(CO_(2)-TPD),IB-temperature programmed desorption(i-C4-TPD)and in-situ IB-Fourier transform infrared spectroscopy(IB-FTIR).Both Ce and Gd finely regulate the bulk and surface structure of the catalyst,thus altering the redox ability,oxygen mobility and storage ability and *** with Ce,Gd addition slightly regulates the variation of Co^(2+)/Co^(3+)redox couples,greatly enhances the interaction among the components on the catalyst,thus only increases the content of surface oxygen species and has little effect on their *** Cecontaining catalyst performs stronger oxygen storage and migration ability,thus leading to the overproduction of surface Odefectspecies,which are proposed to be the active sites for the production of MAL and *** CeGd co-doped catalyst possesses the proper content of surface Odefectspecies,thus exhibits much higher MAL ***,the promoting mechanism of Ce and/or Gd over IB oxidation is ***,this work is helpful for understanding the influence of rare earth elements on the structure of mixed metal oxides and the olefin selective oxidation reaction.

关键词： Mixed metal oxide catalyst Rare earth element Isobutene Selective oxidation Methacrolein

Highly dispersed MgInCe-mixed metal oxides catalyzed direct carbonylation of glycerol and CO_(2)into glycerol carbonate

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Chinese Journal of Chemical Engineering 2024年第8期72卷 153-163页

作者： xufang Chen x.n Shu Yanru Zhu jian Zhang Zhigang Chai Hongyan song Zhe An Jing He State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou 324000China

Glycerol carbonate,an important glycerol value-added product,has been widely used as an active intermediate and inert solvent in the synthesis of cosmetics,detergents,chemical intermediates,polymers,and so *** direct carbonylation from glycerol with CO_(2)is considered a promising route,but still tough work due to the thermodynamic stability and the kinetic inertness of CO_(2).In this work,highlyselective direct carbonylation of glycerol and CO_(2)into glycerol carbonate has been achieved over highly dispersed MgInCe-mixed metal oxides(MgInCe-MMO),which were prepared through the topological transformation derived from the MgInCe-layered double hydroxides(MgInCe-LDHs).By precisely modulating the surface basic-acidic properties and the oxygen vacancies,an efficient carbonylation of glycerol with CO_(2)has been achieved with a selectivity of up to>99%to glycerol *** investigation into the synergistic catalysis of base-acid sites and oxygen vacancies has been clarified.

关键词： Catalytic reaction engineering Glycerol carbonate Direct carbonylation from glycerol Carbon dioxide Mixed metal oxides Synergistic catalysis

Ten-Minute Synthesis of a new Redox-Active Aqueous Binder for Flame-Retardant Li-S Batteries

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Energy & Environmental Materials 2024年第2期7卷 48-57页

作者： Tianpeng Zhang Borui Li Zihui song Wanyuan jiang Siyang Liu Runyue Mao xigao jian Fangyuan Hu School of Materials Science and Engineering State Key Laboratory of Fine ChemicalsFrontiers Science Center for Smart Materials Oriented Chemical Engineering Technology Innovation Center of High Performance Resin Materials(Liaoning Province)Key Laboratory of Energy Materials and Devices(Liaoning Province)Dalian University of TechnologyDalian 116024China State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical EngineeringSchool of Chemical Engineering Technology Innovation Center of High Performance Resin Materials(Liaoning Province)Key Laboratory of Energy Materials and Devices(Liaoning Province)Dalian University of TechnologyDalian 116024China

As a critical role in battery systems,polymer binders have been shown to efficiently suppress the lithium polysulfide shuttling and accommodate volume changes in recent ***,preparation processes and safety,as the key criterions for Li-S batteries'practical applications,still attract less ***,an aqueous multifunction binder(named PEI-TIC)is prepared via an easy and fast epoxy-amine ring-opening reaction(10 min),which can not only give the sulfur cathode a stable mechanical property,a strong chemical adsorption and catalytic conversion ability,but also a fire safety *** Li-S batteries based on the PEI-TIC binder display a high discharge capacity(1297.8 mAh g^(-1)),superior rate performance(823.0 mAh g^(-1)at 2 C),and an ultralow capacity decay rate of 0.035%over more than 800 *** under 7.1 mg cm^(-2)S-loaded,the PEI-TIC electrode can also achieve a high areal capacity of 7.2 mA h g^(-1)and excellent cycling stability,confirming its application ***,it is also noted that TG-FTIR test is performed for the first time to explore the flame-retardant mechanism of polymer *** work provides an economically and environmentally friendly binder for the practical application and inspires the exploration of the flame-retardant mechanism of all electrode components.

关键词： 3D cross-linked network environmentally friendly flame retardant Li-S batteries multifunction binder

Theoretical and experimental investigations on an x-shaped vibration isolator with active controlled variable stiffness

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1371-1386页

作者： Zeyu CHAI J.T.HAn xuyuan song jian ZAnG Yewei ZHAnG Zhen ZHAnG College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China Jacobs School of Engineering University of California San DiegoSan Diego CA 92122U.S.A. Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of EducationNortheastern UniversityShenyang 110819China

A novel x-shaped variable stiffness vibration isolator(x-VSVI)is *** Runge-Kutta method,harmonic balance method,and wavelet transform spectra are introduced to evaluate the performance of the x-VSVI under various *** layer number,the installation angle of the x-shaped structure,the stiffness,and the active control parameters are systematically *** addition,a prototype of the x-VSVI is manufactured,and vibration tests are carried *** results show that the proposed x-VSVI has a superior adaptability to that of a traditional x-shaped mechanism,and shows excellent vibration isolation performance in response to different amplitudes and forms of ***,the vibration isolation efficiency of the device can be improved by appropriate adjustment of parameters.

关键词： bionic vibration isolation x-shaped structure variable stiffness structure nonlinear dynamics prototype experiment

How variable progenitor clones construct a largely invariant neocortex

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national Science Review 2024年第1期11卷 129-144页

作者： Zhongfu Shen Jiajun Yang Qiangqiang Zhang Kuiyu Wang xiaohui Lv xiaolin Hu jian Ma song-Hai Shi new Cornerstone Science Laboratory IDG/McG overn Institute for Brain Research Tsinghua-Peking Center for Life Sciences Beijing Frontier Research Center for Biological Structure School of Life Sciences Tsinghua University Department of Computer Sciences Tsinghua University College of Life Sciences Nankai University Chinese Institute for Brain Research

The neocortex contains a vast collection of diverse neurons organized into distinct layers. While nearly all neocortical neurons are generated by radial glial progenitors(RGPs), it remains largely unclear how a complex yet organized neocortex is constructed reliably and robustly. Here, we show that the division behavior and neuronal output of RGPs are highly constrained with patterned variabilities to support the reliable and robust construction of the mouse neocortex. The neurogenic process of RGPs can be well-approximated by a consistent Poisson-like process unfolding over time, producing deep to superficial layer neurons progressively. The exact neuronal outputs regarding layer occupation are variable; yet, this variability is constrained systematically to support all layer formation, largely reflecting the variable intermediate progenitor generation and RGP neurogenic entry and exit timing differences. Together, these results define the fundamental features of neocortical neurogenesis with a balanced reliability and variability for the construction of the complex.neocortex.

关键词： neocortex radial glial progenitor intermediate progenitor neurogenesis clonal variability layer formation

Annulation Cascades of Cyclosulfonium Salts and Alkenes towards Sulfur-Containing n-Heterocycles by Visible Light/Copper Catalysis

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Chinese Journal of Chemistry 2024年第14期42卷 1637-1643页

作者： Jie Ma xufeng Li Yuqing Chen Yongjia Shi xiuyan song jian Lv Daoshan Yang Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science MOECollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdaoShandong266042 China Zhejiang Wansheng Co. Ltd.LinhaiZhejiang317000 China national Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass Nanjing Forestry UniversityNanjingJiangsu210037 China

Although,great achievements have been made in the synthesis of heterocycles using radical addition/cyclization strategy,developing versatile alkyl radical precursors,especially the non-stabilized long chain alkyl radicals for this strategy still remains a huge ***,we report an efficient annulation cascade reaction between cyclosulfonium salts and alkenes for the synthesis of sulfur-containing n-heterocycles by visible light/copper catalysis under mild *** C—S bond cleavage/radical cascade reaction delivers a variety of corresponding n-heterocycles containing aryl alkyl thioether motifs with good functional group ***,the current system could be used for the late-stage functionalization of complex bioactive molecules.

关键词： Visible light Radical reactions C-C coupling Sulfur heterocycles Photoredox catalysis

Improving mathematical model of burden distribution and correcting chute angle to cope with fluctuation of stock line

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Journal of Iron and Steel Research International 2024年第2期31卷 342-356页

作者： jian-sheng Chen Wen-guo Liu Hao Guo Wang Ding Qing-guo xue Jing-song Wang Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China MCC Capital Engineering&Research Incorporation Limited Beijing100176China Hunan Valin xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina

Accurate evaluations of the burden distribution are of critical importance to stabilize the operation of blast *** mathematical model and discrete element method(DEM)are two attractive methods for predicting burden *** on DEM,the initial velocities of the pellet,sinter,and coke were calculated,and the velocity attenuations of the above three particles between the burden and the chute were *** initial velocity and velocity attenuation were applied to a mathematical model for improving the ***,based on the improved model,a scheme for rectifying the chute angles was proposed to address the fluctuation of the stock line and maintain a stable burden *** validity of the scheme was confirmed via a stable burden distribution under different stock *** mathematical model has been successfully applied to evaluate the online burden distribution and cope with the fluctuation of the stock line.

关键词： Burden distribution Mathematical model Discrete element method Velocity attenuation Stock line fluctuation