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Photo-regulation of 2D supramolecular self-assembly：On-surface photochemistry studied by STM

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Chinese Chemical Letters 2017年第4期28卷 729-737页

作者： Hong-Liang dai Yan-Fang Geng qing-dao Zeng Chen Wang CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology (NCNST) Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

During the past few years,regulation and controlling of the two-dimension（2D） self-assembled supramolecular structure on surface have drawn increasing attention in nanoscience and *** stimuli have been widely used to regulate these 2D *** various external stimuli approaches,photo-regulation as one of the most outstanding means of regulation has been extensively studied because different wave bands can lead to molecular conformation variation and new bonds to gain new *** this review,the photo-regulated self-assembled structure on solid surface as well as the photo-reactions of different molecules substituted with photo-sensitive groups are introduced to give us an insight into on-surface photochemistry,which plays an important role on the nano-devices ***,these photo-sensitive behaviors as well as the formed structures on surface were probed at sub-molecule level by unique scanning tunneling microscopy（STM） technique.

关键词： Scanning tunneling microscopy(STM) Photochemistry Light irradiation 2D self-assembly Molecular template

Construction of two-dimensional(2D) H-bonded supramolecular nanostructures studied by STM

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Chinese Chemical Letters 2013年第3期24卷 177-182页

作者： Jing Xu qing-dao Zeng National Center for Nanoscience and Technology(NCNST)

In this review, a group ot two-dimensional （2D） hydrogen-bonded supramolecular networks developed in our laboratory are discussed. Our attention is mainly focused on：（1） recognition of Fe3＋ through twocomponent molecular networks; （2） site-selective fabrication of 2D fullerene arrays; and （3） fabrication of the nanoporous structure regulated by photoisomerization reaction process. It is envisioned that special supramolecular nanostructures, through H-bonding interactions, can be constructed or reconstructed to be further investigated toward the research of multi-component systems, molecule recognition, single molecular switches, and host-guest supramolecular chemistry.

关键词： Scanning tunneling microscopy (STM)Self-assemblySupramolecular networkHydrogen bonds

Magnetic order driven by orbital ordering in the semiconducting KFe1.5Se2

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Frontiers of physics 2016年第2期11卷 75-81页

作者： qing Jiang dao-Xin Yao State Key Laboratory of Optoelectranic Materials and Technologies School of Physics and Engineering Sun Yat-sen University Guangzhou 5102~5 China

The two-orbital Hubbard model is studied numerically by using the Hartree-Fock approximation in both real space and momentum space, and the ground-state properties of the alkali metal iron selenide semiconducting KFel.5Se2 are investigated. A rhombus-type Fe vacancy order with stripe- type antiferromagnetic （AFM） order is found, as was observed in neutron scattering experiments [J. Zhao, et al., Phys. Rev. Lett. 109, 267003 （2012）]. Hopping parameters are obtained by fitting the experimentally observed stripe AFM phase in real space. These hopping parameters are then used to study the ground-state properties of the semiconductor in momentum space. It is found to be a strongly correlated system with a large on-site Coulomb repulsion U, similar to the AFM Mort insulator -- the parent compound of copper oxide superconductors. We also find that the electronic occupation numbers and magnetizations in the dxz and dyz orbitals become different simultaneously when U 〉 Uc （～3.4 eV）, indicating orbital ordering. These results imply that the rotational symmetry between the two orbitals is broken by orbital ordering and thus drives the strong anisotropy of the magnetic coupling that has been observed by experiments and that the stripe-type AFM order in this compound may be caused by orbital ordering together with the observed large anisotropy.

关键词： iron-based superconductor twoporbital model stripe AFM phase rhombus Fe vacancy order orbital ordering

Adaptive discontinuous finite element quadrature sets over an icosahedron for discrete ordinates method

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Nuclear Science and Techniques 2021年第9期32卷 94-104页

作者： Ni dai Bin Zhang Yi-Xue Chen dao-Gang Lu School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China

The discrete ordinates(S N)method requires numerous angular unknowns to achieve the desired accu-racy for shielding calculations involving strong *** objective is to develop an angular adaptive algorithm in the S N method to automatically optimize the angular distribution and minimize angular discretization errors with lower *** proposed method enables linear dis-continuous finite element quadrature sets over an icosahe-dron to vary their quadrature orders in a one-twentieth sphere so that fine resolutions can be applied to the angular domains that are *** error estimation that operates in conjunction with the spherical harmonics method is developed to determine the locations where more refinement is *** adaptive quadrature sets are applied to three duct problems,including the Kobayashi benchmarks and the IRI-TUB research reactor,which emphasize the ability of this method to resolve neutron streaming through ducts with *** results indicate that the performance of the adaptive method is more effi-cient than that of uniform quadrature sets for duct transport *** adaptive method offers an appropriate placement of angular unknowns to accurately integrate angular fluxes while reducing the computational costs in terms of unknowns and run times.

关键词： Shielding calculation Discrete ordinates method Angular adaptivity Discontinuous finite element

Modeling Morning Commute with Different Kinds of Activities Based on Bottleneck Model

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Journal of Systems Science and Systems Engineering 2023年第4期32卷 444-461页

作者： qing dai Jiajia Zhang Zhengkui Lin School of Management Science and Engineering Dongbei University of Finance and EconomicsDalian116025China School of Maritime Economics and Management Dalian Maritime UniversityDalian116026China

Morning commute problem has always been concerned by researchers in transportation research *** the bottleneck existing in the road network between home and school,this paper studies the household travel with different kinds of activities,i.e.,home-school-home trip and home-school-workplace *** just send their children to school and then go home,which is named school *** need to send their children to school firstly and then go to work,which is named household ***,according to the proportions of two types of travelers and school-work start time difference,the possible equilibrium cases are solved and the conditions for the occurrence of each case are *** from the traditional bottleneck model with a unique equilibrium traffic pattern,the mixed travel case has six possible equilibrium traffic ***,the cost of traveler is analyzed for all possible equilibrium traffic *** shows that equilibrium trip costs of two types of travelers are more sensitive to the number of travelers in that class than the number in another class in all possible equilibrium ***,the influence of school-work start time difference on the total travel cost is *** shows that the total system travel cost can be reduced by appropriately adjusting the difference of school-work start time.

关键词： Morning commute bottleneck model household travel school travel

ARCHITECTURE OF LADDER,TUBULAR AND SIEVE-PLATE POLYMERS PREPARED BY STEPWISE COUPLING POLYMERIZATION

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Chinese Journal of Polymer Science 2000年第3期18卷 195-206页

作者： Rong-ben Zhang Ping Xie dao-rong dai Chun-qing Liu Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 中科院化学所北京

'Stepwise-coupling polymerization' (SCP) is a very useful approach for preparing microstructure-controllable ordered network polymers, including soluble one-dimensional ladderlike polymers (LP) and tubular polymers (TP), and two-dimensional sieve-plate polymers. The novel reactive LPs are important precursors of micro-structure controllable polymers such as 'fishbone-' or 'rowboat-' like mesomorphic polymers and their metal complexes as well as tubular polymers (TPs). They are full of great potential for use as advanced materials.

关键词： stepwise coupling polymerization ladder polysiloxane tubular polymers

Formation of heterocaryotic and homonuclear bridged–dimeric complexes on surface

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Chinese Chemical Letters 2016年第4期27卷 602-606页

作者： Yan-Fang Geng Shi-Li Wu Jing Xu Hong-Liang dai Xiao-Kang Li Ke Deng qing-dao Zeng CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscienceand Technology (NCNST) Beijing 100190 China Key Laboratory of Organo-pharmaceutical Chemistry. Gannan Normal University Ganzhou 341000 China

The formation of coordinated dimeric complexes bridged by axial ligands on surface is observed with the help of a 1,3,5-tris（10-carboxydecyloxy）benzene（TCDB） template through scanning tunneling microscopy（STM）. STM images of molecular adlayers of zinc tetraphenylporphyrin（Zn TPP）, zinc phthalocyanine（Zn Pc）, and their mixture are reported. Zn TPP and Zn Pc can spontaneously form highly an ordered structure with a 1：1 molar ratio, which is different from that of individual Zn Pc. The coordinated bimolecular complexes bridged with axial ligands, simply as Zn Pc–DPP–Zn TPP and Zn Pc–DPE–Zn Pc, are presented and the corresponding surface structures are compared. Zn Pc and Zn TPP can be connected by an axial ligand DPP and formed assembled structures out of surface. Two types of arrays with entirely new structure are obtained for the Zn Pc–DPE–Zn Pc complex. These bridged hybrid complexes provide an example of design of self-organized crystals on the basis of coordination through non-covalent interactions.

关键词： Coordinated dimeric complexes Zinc tetraphenylporphyrin(ZnTPP) Zinc phthalocyanine(ZnPc) Scanning tunneling microscopy(STM) Axial ligands

Low-temperature(NO + O_(2)) adsorption performance of alkaline earth metal-doped C-FDU-15

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Journal of Environmental Sciences 2021年第5期33卷 172-184页

作者： Runping Wu qing Ye Kai Wu Hongxing dai Key Laboratory of Beijing on Regional Air Pollution Control Department of Environmental ScienceCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution ControlKey Laboratory of Advanced Functional MaterialsEducation Ministry of Chinaand Laboratory of Catalysis Chemistry and NanoscienceDepartment of Chemistry and Chemical EngineeringCollege of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China

To improve the removal capacity of NO + O_(2) effectively, the alkaline earth metal-doped order mesoporous carbon(A-C-FDU-15(0.001)(A = Mg, Ca, Sr and Ba)) and Mg-C-FDU-15( x)( x = 0.001-0.003) samples were prepared, and their physicochemical and NO + O_(2) adsorption properties were determined by means of various techniques. The results show that the sequence in(NO + O_(2)) adsorption performance was as follows: Mg-C-FDU-15(0.001)(93.2 mg/g) > Ca-C-FDU-15(0.001)(82.2 mg/g) > Sr-C-FDU-15(0.001)(76.1 mg/g) > Ba-C-FDU-15(0.001)(72.9 mg/g) > C-FDU-15(67.1 mg/g). Among all of the A-C-FDU-15(0.001) samples, Mg-C-FDU-15(0.001) possessed the highest(NO + O_(2)) adsorption capacity(106.2 mg/g). The species of alkaline earth metals and basic sites were important factors determining the adsorption of NO + O_(2) on the A-C-FDU-15( x) samples, and(NO + O_(2)) adsorption on the samples was mainly chemical adsorption. Combined with the results of(NO + O_(2))-temperatureprogrammed desorption((NO + O_(2))-TPD) and in situ diffused reflectance infrared Fourier transform spectroscopy(DRIFTS) characterization, we deduced that there were two main pathways of(NO + O_(2)) adsorption: one was first the conversion of NO and O_(2) to NO_(2) and then part of NO_(2) was converted to NO_(2)^(-) and NO_(3)^(-);and the other was the direct oxidation of NO to NO-2 and NO_(3)^(-).

关键词： C-FDU-15 Alkaline earth metal NO+O_(2)adsorption Adsorption mechanism Adsorption kinetics

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A New Sequential Systems of Linear Equations Algorithm of Feasible Descent for Inequality Constrained Optimization

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Acta Mathematica Sinica,English Series 2010年第12期26卷 2399-2420页

作者： Jin Bao JIAN dao Lan HAN qing Juan XU College of Mathematics and Infornation Science Guangxi University Nanning 530004 P. R. China College of Mathematics and Computer Science Guangxi University for NationalitiesNanning 530006 P. R. China College of Electrical Engineering Guangxi University Nanning 530004 P. R. China Department of Mathematics Shanghai University Shanghai 200444 P. R. China College of Mathematical Science Guangxi Teachers Education University Nanning 530001 P. R. China

Based on a new efficient identification technique of active constraints introduced in this paper, a new sequential systems of linear equations （SSLE） algorithm generating feasible iterates is proposed for solving nonlinear optimization problems with inequality constraints. In this paper, we introduce a new technique for constructing the system of linear equations, which recurs to a perturbation for the gradients of the constraint functions. At each iteration of the new algorithm, a feasible descent direction is obtained by solving only one system of linear equations without doing convex combination. To ensure the global convergence and avoid the Maratos effect, the algorithm needs to solve two additional reduced systems of linear equations with the same coefficient matrix after finite iterations. The proposed algorithm is proved to be globally and superlinearly convergent under some mild conditions. What distinguishes this algorithm from the previous feasible SSLE algorithms is that an improving direction is obtained easily and the computation cost of generating a new iterate is reduced. Finally, a preliminary implementation has been tested.

关键词： Inequality constraints nonlinear optimization systems of linear equations global conver-gence superlinear convergence