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Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

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Tungsten 2025年第1期7卷 80-87页

作者： Fang-Qian Wang Yin Zhang Wei-Wei Wang Mei-Qian Fu Hong-bing Mo Wei-dong Yu Chao liu Jun Yan College of Chemistry and Chemical Engineering Central South University Junior Education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.Furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词： Arsenic CO2 conversion Oxazolidinone Polyoxometalates Vanadium

Enhanced subacute ischemic stroke treatment via multistage drug delivery system design for combination therapy

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Science China Chemistry 2025年

作者： Xihan Xu Juan-Juan Li Jiamin Li Hui-Yan Zhang Yilin Qi bing-Sen Shi Tianqi Li Shan-Shan Su Weitao Zhao Chang Chen Zhongying Gong Huiyu liu Ke-Rang Wang dong-sheng Guo Xue Xue State Key Laboratory of Medicinal Chemical Biology College of Pharmacy Nankai University College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Key Laboratory of Functional Polymer Materials (Ministry of Education) Frontiers Science Center for New Organic Matter Collaborative Innovation Center of Chemical Science and EngineeringNankai University College of Chemistry and Materials Science State Key Laboratory of New Pharmaceutical Preparations and Excipients Key Laboratory of Medicinal Chemistry and Molecular Diagnosis (Ministry of Education) Key Laboratory of Chemical Biology of Hebei Province Hebei Research Center of the Basic Discipline of Synthetic Chemistry Hebei University Department of Neurology Tianjin First Central Hospital School of Medicine Nankai University Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic-Inorganic Composites Beijing Laboratory of Biomedical Materials Bionanomaterials & Translational Engineering Laboratory Beijing Key Laboratory of BioprocessBeijing University of Chemical Technology

The management of acute ischemic stroke remains challenging due to its abrupt onset and the narrow treatment window,resulting in high rates of disability and *** therapy for neuroprotection and neurorepair strategies provided new hopes for subacute stroke *** we designed a multistage nanodelivery system that matches the unique microenvironment of the subacute phase of stroke,which utilizes calixarene as a building block to effectively load the neuroprotective drug *** calixarene is designed with glycosidic linkages targeting the glucose transporter 1 (GLUT1)on the blood-brain barrier (BBB) and azo bonds that are responsive to hypoxic ***,the decomposed calixarene molecules themselves possess intrinsic bio-activation to modulate inflammatory responses,achieving a multistage therapeutic approach that transitions from targeting to release and finally to *** approach combines anti-inflammation and neuroprotection,providing a multi-level treatment *** system was validated in a rat model of permanent middle cerebral artery occlusion (pMCAO),demonstrating that intravenous administration of the nanodelivery system repairs brain damage and improves motor function 24 h post-pMCAO *** work offers a precise and integrative strategy for stroke patients missing the acute therapy window to improve functional recovery and enhance the effect of comprehensive treatment.

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Research on conductive-material-filled electrodes for sidewall insulation performance in micro electrochemical machining

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Advances in Manufacturing 2023年第3期11卷 509-522页

作者： Guo-dong liu Yu-Lan Zhu sheng-gui liu Chao-Jiang Li School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081People's Republic of China Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People's Republicof China

In micro electrochemical machining(ECM)processes,stray corrosion causes undesired metal dissolution and the deterioration of shape *** a sidewall-insulated electrode is an effective approach to suppressing stray *** sidewall-insulated electrodes are made of metal substrate and non-metallic thin ***,the thin-film insulating materials attached to a metal substrate are susceptible to damage in an electrolytic *** study presents a novel concept of the conductive-material-filled electrode for better sidewallinsulation *** micro-scale quartz tube serves as the insulating *** available conductive fillers including metal wire,molten metals,and silver powder are filled inside the working cathode of the quartz ***,the metal-wire-filled electrode,moltenmetal-filled electrode,and nano-powder-filled electrode are designed and *** the verification results of electrode toughness,material removal rate,and surface topography,the metal-wire-filled electrode and moltenmetal-filled electrode exhibit the same performance as a traditional metal-based electrode and much better *** contrast,the nano-powder-filled electrode is unable to withstand long-term ECM processes because of the loss of cured powder *** ECM experiments,microstructures with steep sidewalls(taper angle<9.7°)were machined using the metal-wire-filled electrode and molten-metal-filled electrode,which could replace the traditional electrode,achieving a longer service life and superior sidewall-insulation performance.

关键词： Electrochemical machining(ECM) Conductive-material-flled electrode Stray corrosion Sidewall insulation Quartz substrate

Modeling urban scale human mobility through big data analysis and machinelearning

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Building Simulation 2024年第1期17卷 3-21页

作者： Yapan liu bing dong Department of Mechanical&Aerospace Engineering Syracuse University263 Link HallSyracuseNY 13244USA

In the United States,the buildings sector consumes about 76%of electricity use and 40% of all primary energy use and associated greenhouse gas *** behavior has drawn increasing research interests due to its impacts on the building energy ***,occupant behavior study at urban scale remains a challenge,and very limited studies have been *** an effort to couple big data analysis with human mobility modeling,this study has explored urban scale human mobility utilizing three months Global Positioning System(GPS)data of 93,o00 users at Phoenix Metropolitan *** research extracted stay points from raw data,and identified users'home,work,and other locations by Density-Based Spatial Clustering ***,daily mobility patterns were constructed using different types of *** propose a novel approach to predict urban scale daily human mobility patterns with 12-hour prediction horizon,using Long Short-Term Memory(LSTM)neural network *** shows the developed models achieved around 85%average accuracy and about 86%mean *** developed models can be further applied to analyze urban scale occupant behavior,building energy demand and flexibility,and contributed to urban planning.

关键词： urban human mobility big data analysis urban scale occupant behavior recurrent neural networks

Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

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Petroleum Science 2024年第2期21卷 791-805页

作者： Xu Zeng Tao Yang Jian-Wei Feng Cong-sheng Bian Ming Guan Wei liu bing-cheng Guo Jin dong Research Institute of Petroleum Exploration and Development China National Petroleum CorporationBeijing100083China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China School of Earth Sciences China University of PetroleumQingdao266400ShandongChina

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in th

关键词： Fractures Development characteristics Controlling factors Shale oil Sweet spot

Theoretical Study on the Dark Oxidation Reaction Mechanism of Ethers

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1402-1408页

作者： WANG gui-Xiu ZHU Rong-Xiu ZHANG dong-Ju liu cheng-Bu School of Chemistry and Chemical Engineering Shandong University Jinan 250100 China

The dark oxidation reactions of ethers including aether, isopropyl ether, phenyl isopropyl ether, and benzyl isopropyl ether have been studied by using density functional theory calculations. The structures of initial Contact charge transfer complexes （CCTCs）, transition states and caged radical intermediates have been located at the B3LYP/6-31G （d） level, The bonding nature of ethers with triplet 02 in CCTCs has been analyzed, and the detailed mechanism of dark oxidation reactions of ether is presented clearly.

关键词： ethers dark oxidation contact charge transfer complex reaction mechanism DFT

Uniform Hypergraphs under Certain Intersection Constraints between Hyperedges

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Acta Mathematica Sinica,English Series 2023年第6期39卷 1153-1170页

作者： Yan dong BAI Bin Long LI Jiu Qiang liu sheng gui ZHANG School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710072P.R.China School of Mathematical Sciences Xi'an University of Finance and EconomicsXi'an 710100P.R.China Department of Mathematics Eastern Michigan UniversityYpsilantiMI 48197USA

A hypergraph H is an(n,m)-hypergraph if it contains n vertices and m hyperedges,where n≥1 and m≥0 are two *** k be a positive integer and let L be a set of nonnegative integers.A hyper graph H is k-uniform if all its hyperedges have the same size k,and H is L-intersecting if the number of common vertices of every two hyperedges belongs to *** this paper,we propose and investigate the problem of estimating the maximum k among all k-uniform L-intersecting(n,m)-hypergraphs for fixed n,m and *** will provide some tight upper and lower bounds on k in terms of n,m and L.

关键词： Uniform hypergraph Erdos-Ko-Rado theorem extremal set theory

The Microwave Characteristics of an In_(0.4)Ga_(0.6)As Metal-Oxide-Semiconductor Field-Effect Transistor with an In_(0.49)Ga_(0.51)P Interfacial Layer

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Chinese Physics Letters 2013年第8期30卷 160-163页

作者： liu gui-Ming CHANG Hu-dong SUN bing liu Hong-Gang Microwave Device and IC Department Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029

A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-length In_(0.4)Ga_(0.6)As MOSFET with a 5-nm Al_(2)O_(3) dielectric layer provides a current gain cutoff frequency of 16.7 GHz and a maximum oscillation frequency of 52 GHz.A semi-empirical small-signal-parameter extraction technique accounting for the low frequency anomaly of this MOSFET device is described,which is based on on-wafer S-parameter *** agreement between measured and simulated scattering parameters as well as the physically realistic circuit elements demonstrates the validity of this approach.

关键词： scattering transistor parameter

ALTERNATELY LINEARIZED IMPLICIT ITERATION METHODS FOR SOLVING QUADRATIC MATRIX EQUATIONS

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Journal of Computational Mathematics 2014年第3期32卷 306-311页

作者： bing gui Hao liu Minli Yan School of Science Nanjing Forestry University Nanjing 210037 China College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

A numerical solution of the quadratic matrix equations associated with a nonsingular M-matrix by using the alternately linearized implicit iteration method is considered. An iteration method for computing a nonsingular M-matrix solution of the quadratic matrix equations is developed, and its corresponding theory is given. Some numerical examples are provided to show the efficiency of the new method.

关键词： Quadratic matrix equation Alternately iteration M-matrix Matrix transformation.