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Improved Clustering and Resource Allocation for Ultra-Dense networks

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china Communications 2020年第2期17卷 220-231页

作者： Xinji tian Wenjie Jia School of Physics and Electronic Information Engineering Henan Polytechnic University

To reduce the interference among small cells of Ultra-Dense networks(UDn),an improved Clustering-Assisted Resource Allocation(CARA)scheme is proposed in this *** proposed scheme is divided into three ***,an Interference-Limited Clustering Algorithm(ILCA)based on interference graph corresponding to the interference relationship between Femtocell Base Stations(FBSs),is proposed to group FBSs into disjoint clusters,in which a pre-threshold is set to constrain the sum of interference in each cluster,and a Cluster Head(ch)is selected for each ***,ch performs a twostage sub-channel allocation within its associated cluster,where the first stage assigns one sub-channel to each user of the cluster and the second stage assigns a second sub-channel to some ***,a power allocation method is designed to maximize throughput for a given clustering and sub-channel *** results indicate that the proposed scheme distributes FBSs into each cluster more evenly,and significantly improves the system throughput compared with the existing schemes in the same scenario.

关键词： ultra-dense networks clustering resource allocation system throughput interference cancellation

Ab initio Study of the Potential Energy Surface and Product Branching Ratios for Reaction of O（^1D） with C2H5CI

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chinese Journal of chemical Physics 2009年第1期22卷 87-96页

作者： chong-fu Song Zhi-mei tian Quan-xin Li tian-jing He Department of chemistry Fuyang Teacher's College Fuyang 236041 China Department of chemical Physics University of Science and Technology of China Hefei 230026 China

The potential energy surface of O（^1D）＋C2H5Cl reaction was studied using QCISD（T）/6- 311＋＋G（d,p）//MP2/6-31G（d,p） method. The calculations reveal an insertion-elimination mechanism. The insertion reaction of O（^1D） and C2H5Cl produces two energy-rich intermediates, IM1 and IM2, which subsequently decompose into various products. The calculations of the branching ratios of various products formed through the two intermediates were carried out using RRKM （Rice-Ramsperger-Kassel-Marcus） theory at the collision energies of 0, 20.9, 41.8, 62.7, 83.6, 104.5, and 125.4 kJ/mol. HCl is the main decomposition product for IM1; ch2OH is the main decomposition product for IM2. Since IM1 is more stable than IM2, HCl is probably the main product of the O（^1D）＋C2H5Cl reaction.

关键词： C2H5Cl Branching ratio Rate constant

Ternary non-noble metal zinc-nickel-cobalt carbonate hydroxide cocatalysts toward highly efficient photoelectrochemical water splitting

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Journal of Materials Science & Technology 2018年第6期34卷 899-904页

作者： Fengren Cao Wei tian Liang Li College of Physics Optoelectronics and Energy Center for Energy Conversion Materials & Physics (CECMP) Jiangsu Key Laboratory of Thin Films Soochow University

TiO2 photoanodes have aroused intensive research interest in photoelectrochemical （PEC） water splitting. However, they still suffer from poor electron-hole separation and sluggish oxygen evolution dynamics, leading to the low photoconversion efficiency and limiting commercial application. Here, we designed and fabricated novel ternary non-noble metal carbonate hydroxide （ZnC-ch） nanosheet cocatalysts and integrated them with TiO2 nanorod arrays as highly efficient photoanodes of PEC cells. Compared with the pristine TiO2, the photocurrent of photoanode with the optimal amount of ZnC-ch represents 3.2 times enhancement, and the onset potential is shifted toward the negative potential direction of 62 mV, The remarkable enhancement is attributed to the suppressed carrier recombination and enhanced charge transfer efficiency at the interface of TiO2, ZnC-ch and electrolyte, which is closely related to the zinc elements modulated intrinsic activity of catalysts. Our results demonstrate that the introduction of multimetallic ZnC-ch cocatalysts onto photoanodes is a promising strategy to improve the PEC efficiency.

关键词： Photoelectrochemical cells TiO2 Cocatalysts Carbonate hydroxides Photoanodes

Theoretical Study of Haloacetonitrile Anions： ch2XCn^- （X=F, Cl）

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chinese Journal of chemical Physics 2008年第3期21卷 255-262页

作者： Xin-wen Zhang Mei Li Shan-xi tian Hefei national Laboratory for Physical Sciences at Microscale University of Science and Technologyof China Hefei 230025 China Department of chemical Physics University of Science and Technology of China Hefei 230026China

Haloacetonitrile anions ch2XCn- （X=F, Cl） were studied by HF-SCF, Becke3-LYP, and MP2 methods together with the Dunning＇s basis set aug-cc-PVTZ. The vertical electron attachments to the neutral are endothermic. The geometrically optimized ch2FCn^- is mainly a valence-bounded anion and ch2FCn→ch2Cn＋F^- is a nonadiabatic dissociation. This theoretical study in good agreement with the experimental results shows that the Becke3-LYP method is reasonable in describing the electronic structures of anions and dissociative attachment dynamics, while significant differences between MP2 and Becke3-LYP results are shown for the dissociation potential curves of ch2ClCn→ch2Cn＋Cl^-.

关键词： Haloacetonitrile Electron attachment Dissociation dynamics Electron correlation effect

A Multifunctional Cobalt (Ⅱ) Metal-Organic Framework with nanoporous channels for Gas and Dye Absorption, and Magnetic Performance

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chemical Research in chinese Universities 2023年第6期39卷 915-920页

作者： CAO Weiwei MA Zhilong tian Li tianjin Key Laboratory of Structure and Performance for Functional Molecules College of ChemistryTianjin Normal UniversityTianjin 300387P.R.China

Coordination polymer{[Co(BTIA)(H_(2)O)0.5]·1.5ch_(3)OH}n(Co-1)was synthesized from Co(nO_(3))_(2)·6H_(2)O and multidentate ligand 4,6-bis-(4H-1,2,4-triazol-1-yl)-isophthalic acid(H_(2)BTIA)under solvothermal *** analysis found that Co-1 was a(4^(4)·6^(2))_(2)(4^(16)·6^(12))3D framework with one dimensional channels,which gives it good adsorption performance for greenhouse gas CO_(2) and anionic dyes CR^(2-) and TY^(-).In particular for the large-size CR^(2-),it behaves a very fast removal *** addition,magnetic analysis discloses that antiferromagnetic(AF)coupling exists in binuclear cobalt unit.

关键词： Co(Ⅱ)ion Metal-organic framework(MOF) Gas adsorption Dye adsorption Congo red

Investigation of the Laminar Premixed n-Propylamine Flame

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Journal of Thermal Science 2022年第3期31卷 854-866页

作者： LI Wang chEn Jintao YAnG Jiuzhong tian Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of chinese Academy of Sciences Beijing100049China national Synchrotron Radiation Laboratory University of Science and TechnologyHefei230029China

The laminar premixed n-propylamine(nPA)flame with equivalence ratio of 1.70 has been investigated at 4666.28 Pa using tunable synchrotron photoionization and molecular-beam mass spectrometry *** structures and mole fractions of 40 species were ***,allylamine,butadiyne,vinylacetylene,1,3-butadiene,1-butene,2-butene,n-butyl radical,1,3-cyclopentadiene,cyclopentene,2-pentene,benzene,toluene,ethylbenzene,2-propen-1-imine,cyclopropanimine,pyrrole,2-butenenitrile and n-butylamine were newly identified in the amine *** fraction profiles of some species including reactants,intermediates and products in the nPA flame were *** and n_(2)were observed as the primary n-containing products in the nPA flame,which was different from the result that nO was the major n-containing products in previous studies of nitrogen *** bond energies of nPA were calculated through quantum chemistry calculations on the basis of density functional theory at the CBS-QB3 *** showed that the ch_(3)ch_(2)-ch_(2)nH_(2)bond was the weakest and nPA mainly decomposed to ch_(2)nH_(2)and C_(2)H_(5)*** H-abstractions at C_(α)by OH/O(nPA+OH=ch_(3)ch_(2)chnH_(2)+H_(2)O and nPA+O=ch_(3)ch_(2)chnH_(2)+OH)had significant promoting effects on nPA *** n conversion chain of nPA under flame conditions was proposed and detailed analysis with respect to intermediates especially the nitrogen-containing species were *** results will enrich the understanding of nPA flame and are essential to further establish the kinetic mechanism.

关键词： n-propylamine low-pressure laminar premixed flame intermediates mole fraction quantum chemistry calculation molecular beam mass spectrometry

Anilido-imine Zinc Complexes： Efficient Catalysts for Ring-opening Polymerization ofL-Lactide

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chemical Research in chinese Universities 2013年第1期29卷 48-50页

作者： YAO Wei CUI ning XUE Ying-zhao LIU tian-tian WAnG Yan School of Resources and Environment University of Jinan Jinan 250022 P. R. China

A series of anilido-imine zinc complexes ortho-C6H4（ch：nAr）（nAr）ZnEt[Ar=2,6-Me2C6H3（2a）; Ar=2,6-Et2C6H3（2b）] was synthesized, characterized and used as catalysts for the ring-opening polymerization of L-lactide in the presence of benzyl alcohol. The effects of the structures of catalysts and reaction conditions on the reactivity were investigated. The polymerization of L-lactide initiated by each of these complexes was found to take place with a controlled manner.

关键词： Anilido-imine ligand Zinc complex Ring-opening polymerization Lactide

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

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nano Research 2024年第1期17卷 5-17页

作者： tian Wang Yating Wang Yuhang Li chunzhong Li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(ch_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of ch_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-ch_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

Preparation of mesoporous silica microspheres with multi-hollow cores and their application in sustained drug release

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Particuology 2010年第5期8卷 447-452页

作者： chen Zhang tian Hou Jianfeng chen Lixiong Wen Key Lab for nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Research Center of the Ministry of Education for High Gravity Engineering & Technology Beijing University of Chemical Technology Beijing 100029 China

Mesoporous silica microspheres with multi-hollow cores （MSMMCs） were prepared by an O1/W/O2 double emulsion technique. When tetraethyl orthosilicate （TEOS） was hydrolyzed in the O1/W/O2 double emulsion with P123 （a triblock copolymer with a formula of HO（ch2ch20）20（ch2ch（ch3）O）70（ch2ch2O）20H） dissolved in the aqueous phase, the internal oil droplets would serve as templates for the empty hollow cores, P123 function as templates for the mesopores in the shell, and the aqueous phase act as space-limiting micro-reactors for the hydrolysis process, thus forming MSMMCs with controllable size and hollow cores. After further modification by a high-temperature aging process, the prepared MSMMCs had a diameter of 2-10 μm, with macromulti-hollow cores with a size of 100-1000 nm, mesopores in the shell with a size of 3.8-4.4 nm, and a surface area of 383-735 m2/g. In addition, MSMMCs were used as carriers to load avermectin through an immersing and evaporating process, and the loaded avermectin showed a well sustained release behavior from the MSMMCs matrix. This study demonstrated a promising and simple method for preparing silica micro-particles with porous multi-hollow core structure for sustained release applications.

关键词： SilicaPreparationHollow structureSustained release