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Polarization or Diffusion?Spatio-temporal Evolution of Urban Technological Innovation Capacity in China's Five Urban Agglomerations

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Chinese Geographical Science 2022年第6期32卷 946-962页

作者： CAO Jinxian LI Shengning yang qingyuan School of International Relations and Public Affairs Fudan UniversityShanghai 200433China School of New Media Peking UniversityBeijing 100091China Hanhong College Southwest UniversityChongqing 400715China School of Geographical Sciences Southwest UniversityChongqing 400715China Key Laboratory of Monitoring Evaluation and Early Warning of Territorial Spatial Planning ImplementationMinistry of Natural ResourcesChongqing 401147China China Urban Agglomeration Research Base Alliance Chongqing 400715China West Asia Geographical Research Center of Chinese Geographical Society Chongqing 400715China

Under the background of collaborative innovation,innovation spillovers at urban agglomeration(UA)level is an important issue but rarely *** balanced panel data of innovation activities in China’s five UAs from 2003 to 2016,this paper shows spatio-temporal evolution process of their technological innovation capacity with discussing polarization-diffusion patterns,and simultaneously examines driving factors of that evolution *** report three main findings:1)there is a high degree of concentration in technological innovation capacity distribution within all China’s five UAs,linked by economic and innovation collaboration.2)Innovation capacity increase of China’s five UAs is driven by government’s investment in science and technology(S&T)to a large extent,followed by influences of infrastructure facilities construction,human capital for S&T,as well as transformation of industrial structure,with great disparities emerged between UAs in our sample period.3)While the intra-region innovation gaps are reducing in yangtze River Delta Urban Agglomeration(YRD)with obvious innovation diffusion,urban agglomeration in middle reaches of the yangtze River(MYR)is still dominated by innovation polarized *** in polarization-diffusion patterns between these two UAs may be explained by opposite returns of industrial structure and internet *** findings contribute to more effective policy making in promoting innovation development when reducing regional inequality through innovation diffusion.

关键词： urban agglomerations urban innovation spatial effects polarization and diffusion

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Prediction of methane storage in covalent organic frameworks using big-data-mining approach

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Chinese Journal of Chemical Engineering 2021年第11期34卷 286-296页

作者： Huan Zhang Peisong yang Duli Yu Kunfeng Wang qingyuan yang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China

A combination of computational materials screening and machine learning(ML)technique is being adopted as a popular approach to study various materials toward application of *** this work,we began with high-throughput molecular simulations to calculate the methane storage(6.5 MPa)and deliverable(6.5-0.58 MPa)capacities of 404,460 covalent organic frameworks(COFs)at 298 ***,the full data sets with 23 features were randomly split into training and test sets in a ratio of 20:80,which were applied to evaluate the prediction abilities of several ML algorithms,including gradient boosting decision tree(GBDT),neural network(NN),support vector machine(SVM),random forest(RF)and decision tree(DT).The results indicate that the RF model has the highest prediction accuracy,which was further employed to reduce the dimension of features space and quantitatively analyze the relative importance of each feature *** binary classification predictors built using the features with the highest influence weight can give a successful identification of top-performing candidates from the test set containing 323,168 COFs with an accuracy exceeding 96%.The deliverable capacities of the identified COFs were found to outperform those reported so far for various *** findings may provide a useful guidance for the design and synthesis of new high-performance materials for methane storage application.

关键词： Covalent organic framework Monte Carlo simulation Methane Machine learning Model

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Large-scale computational screening of metal–organic frameworks for D_(2)/H_(2) separation

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Chinese Journal of Chemical Engineering 2023年第2期54卷 323-330页

作者： Fei Wang Zhiyuan Bi Lifeng Ding qingyuan yang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China Department of Chemistry Xi'an Jiaotong-Liverpool UniversitySuzhou 215123China

Deuterium(D_(2)) is one of the important fuel sources that power nuclear fusion reactors. The existing D_(2)/H_(2) separation technologies that obtain high-purity D_(2) are cost-intensive. Recent research has shown that metal-organic frameworks(MOFs) are of good potential for D_(2)/H_(2) separation application. In this work, a high-throughput computational screening of 12020 computation-ready experimental MOFs is carried out to determine the best MOFs for hydrogen isotope separation application. Meanwhile, the detailed structure-performance correlation is systematically investigated with the aid of machine learning. The results indicate that the ideal D_(2)/H_(2) adsorption selectivity calculated based on Henry coefficient is strongly correlated with the 1/ΔAD feature descriptor;that is, inverse of the adsorbility difference of the two adsorbates. Meanwhile, the machine learning(ML) results show that the prediction accuracy of all the four ML methods is significantly improved after the addition of this feature descriptor. In addition, the ML results based on extreme gradient boosting model also revealed that the 1/ΔAD descriptor has the highest relative importance compared to other commonly-used descriptors. To further explore the effect of hydrogen isotope separation in binary mixture, 1548 MOFs with ideal adsorption selectivity greater than 1.5 are simulated at equimolar conditions. The structure-performance relationship shows that high adsorption selectivity MOFs generally have smaller pore size(0.3-0.5 nm) and lower surface area. Among the top 200 performers, the materials mainly have the sql, pcu, cds, hxl, and ins ***, three MOFs with high D_(2)/H_(2) selectivity and good D_(2) uptake are identified as the best candidates,of all which had one-dimensional channel pore. The findings obtained in this work may be helpful for the identification of potentially promising candidates for hydrogen isotope separation.

关键词： Metal–organic frameworks Computational screening Hydrogen isotope separation

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Screening and design of COF-based mixed-matrix membrane for CH_(4)/N_(2) separation

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Chinese Journal of Chemical Engineering 2022年第2期35卷 170-177页

作者： Tongan Yan Dahuan Liu qingyuan yang Chongli Zhong State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Separation Membranes and Membrane Processes Tiangong UniversityTianjin 300387China

Membrane separation is a high-efficiency,energy-saving,and environment-friendly separation *** organic framework(COF)-based mixed-matrix membranes(MMMs)have broad application prospects in gas separation and are expected to provide new solutions for coal-bed methane ***,a high-throughput screening method is used to calculate and evaluate COF-based MMMs for CH_(4)/N_(2) *** design rules are proposed from thermodynamic and kinetic points of view using the computation-ready,experimental *** our database containing 471,671 generated COFs,5 COF membrane materials were screened with excellent membrane selectivities,which were then used as the filler of MMMs for separation performance *** them,BAR-NAP-Benzene_CF_(3) combined with polydimethylsiloxane and styrene-b-butadiene-b-styrene show high CH_(4) permeability of 4.43×10^(-13) mol·m·s^(-1)·Pa^(-1)·m^(-2) and high CH_(4)/N_(2) selectivity of 9.54,*** obtained results may provide reasonable information for the design of COF-based membranes for the efficient separation of CH_(4)/N_(2).

关键词： Covalent organic frameworks Methane Molecular simulations Mixed-matrix membrane Nitrogen Separation

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Analyzing acetylene adsorption of metal-organic frameworks based on machine learning

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Green Energy & Environment 2022年第5期7卷 1062-1070页

作者： Peisong yang Gang Lu qingyuan yang Lei Liu Xin Lai Duli Yu College of Information Science and Technology Beijing University of Chemical TechnologyBeijing100029China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China

Metal-organic frameworks(MOFs) containing open metal sites are important materials for acetylene(C_(2)H_(2)) ***,it is inefficient or even impossible to search suitable MOFs by molecular simulation method in nearly infinite MOFs ***,machine learning(ML) methods are adopted in the material screening and prediction of high-performance *** this paper,architecture,chemical and structural features are used to analyze the C_(2)H_(2) adsorption performance of the *** ML algorithms are applied to perform classification and regression analysis to the factors affecting material *** decision tree(DT) algorithm,it is found that only PV,GSA,and Cu-OMS are sufficient to determine the high adsorption of the ***,the influence of topology on the performance of MOFs is *** Boosting Decision Tree(GBDT),Support Vector Machine(SVM),and Back Propagation Neural Network(BPNN),are introduced to analyze the quantitative structure-property relationship(QSPR) between C_(2)H_(2) adsorption and the features of *** prediction of the GBDT model is found to have the highest accuracy,with R~2 as 0.93 and RMSE as *** addition,the GBDT model is used for feature analysis,and the contribution of each feature to the performance is obtained,which is of great significance for the design and analysis of *** successful application of ML to MOFs screening greatly reduce the calculation time and provides important reference for the design and synthesis of new MOFs.

关键词： adsorption acetylene infinite

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High-throughput computational screening of Cu-MOFs with open metal sites for efficient C_2H_2/C_2H_4 separation

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Green Energy & Environment 2020年第3期5卷 333-340页

作者： Lei Liu Lei Wang Dahuan Liu qingyuan yang Chongli Zhong State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Separation Membranes and Membrane Processes TianGong UniversityTianjin 300387China

Cost effective separation of acetylene(C_2H_2)and ethylene(C_2H_4)is of key importance to obtain essential chemical raw materials for polymer *** to the low compression limit of C_2H_2,there is an urgent demand to develop suitable materials for efficiently separating the two gases under ambient *** this paper,we provided a high-throughput screening strategy to study porous metal-organic frameworks(MOFs)containing open metal sites(OMS)for C_2H_2/C_2H_4 separation,followed by a rational design of novel MOFs in-silico.A set of accurate force fields was established from ab initio calculations to describe the critical role of OMS towards guest *** a large-scale computational screening of 916 experimental Cu-paddlewheel-based MOFs,three materials were identified with excellent separation *** structure-performance relationships revealed that the optimal materials should have the largest cavity diameter around 5-10?and pore volume in-between 0.3-1.0 cm^3 g^(-1).Based on the systematic screening study result,three novel MOFs were further designed with the incorporation of fluorine functional *** results showed that Cu-OMS and the-F group on the aromatic rings close to Cu sites could generate a synergistic effect on the preferential adsorption of C_2H_2 over C_2H_4,leading to a remarkable improvement of C_2H_2 separation performance of the *** findings could provide insight for future experimental design and synthesis of high-performance nanostructured materials for C_2H_2/C_2H_4 separation.

关键词： Acetylene and ethylene Metal-organic frameworks Open metal sites Large-scale computation Materials design

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Inferring trophic variation for Antarctic krill(Euphausia superba) in the Antarctic Peninsula from the austral fall to early winter using stable isotope analysis

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Acta Oceanologica Sinica 2018年第6期37卷 90-95页

作者： ZHU Guoping ZHANG Haiting SONG Qi yang yang WANG Shaoqin yang qingyuan College of Marine Sciences Shanghai Ocean University Shanghai 201306 China National Engineering Research Center for Oceanic Fisheries Shanghai 201306 China Polar Marine Ecosystem Group Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources Shanghai Ocean University Ministry of Education Shanghai 201306 China

The Antarctic krill（Euphausia superba） is a key species in the Southern Ocean ecosystem and an important link in the food web of the Antarctic ecosystem. The trophic information for this species during the transition from the austral fall to the winter is important to understand its poorly known overwintering mechanisms. However, the few studies on the topic differ in their results, in terms of both spatial and temporal variables. We investigated the size dependence and monthly and regional variation in δ^（13） C and δ^（15） N values of adult krill in the Antarctic Peninsula, in the austral fall（April to May） and the early winter（June）. We aimed to examine the trophic variations of krill occurred during this period, and the relationship between krill and their feeding environment in the Antarctic marine ecosystem. The following results were obtained：（1） no significant relationship was observed between size and the δ13 C value of krill, but the δ15 N value of krill presented a remarkable association with size;（2）the δ13 C values of krill increased during the austral fall, but no remarkable variation existed at the onset of winter,and the δ15 N values were not significant different during this period;（3） mean δ15 N values of krill differed significantly between the Bransfield Strait and the South Shetland Islands. Our data imply that adult krill present size-, season-, and region-dependent trophic variation during the transition from austral fall to early winter in the Antarctic Peninsula.

关键词： Euphausia superba stable isotope trophic variation Antarctic Peninsula feeding habit

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Large-scale simulations of CO_(2) diffusion in metal-organic frameworks with open Cu sites

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Chinese Journal of Chemical Engineering 2022年第2期35卷 1-9页

作者： Tongan Yan Minman Tong qingyuan yang Dahuan Liu Yandong Guo Chongli Zhong State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou 221116China College of Mathematics Science Bohai UniversityJinzhou 121013China State Key Laboratory of Separation Membranes and Membrane Processes Tiangong UniversityTianjin 300387China

Understanding CO_(2) diffusion behavior in functional nanoporous materials is beneficial for improving the CO_(2) adsorption,separation,and conversion ***,it is a great challenge for studying the diffusion process in ***,CO_(2) diffusion in 962 metal–organic frameworks(MOFs)with open Cu sites was systematically investigated by theoretical methods in the combination of molecular dynamic simulations and density functional theory(DFT)calculations.A specific force field was derived from DFT-D2 method combined with Grimme’s dispersion-corrected(D2)density functional to well describe the interaction energies between Cu and CO_(2).It is observed that the suitable topology is conductive to CO_(2) diffusion,and 2D-MOFs are more flexible in tuning and balancing the CO_(2) adsorption and diffusion behaviors than *** addition,analysis of diffusive trajectories and the residence times on different positions indicate that CO_(2) diffusion is mainly along with the frameworks in these MOFs,jumping from one strong adsorption site to *** is also influenced by the electrostatic interaction of the ***,the obtained information may provide useful guidance for the rational design and synthesis of MOFs with enhanced CO_(2) diffusion performance for specific applications.

关键词： Metal-organic frameworks Open Cusites Molecular simulations Carbon dioxide Diffusion

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High-throughput computational screening and design of nanoporous materials for methane storage and carbon dioxide capture

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Green Energy & Environment 2018年第2期3卷 107-119页

作者： Minman Tong Youshi Lan qingyuan yang Chongli Zhong School of Chemistry and Materials Science Jiangsu Normal University Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology

The globally increasing concentrations of greenhouse gases in atmosphere after combustion of coal-or petroleum-based fuels give rise to tremendous interest in searching for porous materials to efficiently capture carbon dioxide(CO_2) and store methane(CH4), where the latter is a kind of clean energy source with abundant reserves and lower CO_2 emission. Hundreds of thousands of porous materials can be enrolled on the candidate list, but how to quickly identify the really promising ones, or even evolve materials(namely, rational design high-performing candidates) based on the large database of present porous materials? In this context, high-throughput computational techniques, which have emerged in the past few years as powerful tools, make the targets of fast evaluation of adsorbents and evolving materials for CO_2 capture and CH_4 storage feasible. This review provides an overview of the recent computational efforts on such related topics and discusses the further development in this field.

关键词： High-throughput computation Screening and design Nanoporous materials CO2 capture CH4 storage

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Use of additive and pretreatment to control odors in municipal kitchen waste during aerobic composting

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Journal of Environmental Sciences 2015年第11期27卷 83-90页

作者： Jing Yuan qingyuan yang Zhiye Zhang Guoxue Li Wenhai Luo Difang Zhang College of Resources and Environmental Science China Agricultural University School of Civil Mining and Environmental Engineering University of Wollongong

The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used20-L reactors and each test lasted 28 days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15%（wet weight） bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride（FeC l3）. Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2 S to be emitted, but had little impact on the amount of NH3 emitted. The FeC l3 was found to act as an effective chemical flocculant,and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeC l3 emitted 42% less NH3 and 76% less H2 S during composting than did pure kitchen waste.

关键词： Aerobic composting Kitchen waste Pretreatment Ammonia Hydrogen sulfide

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