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Chinese Chemical Letters 2012年第3期23卷 347-350页

作者： Fei Shao Xu Feng ni Zhi quan Shen MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

A novel graft copolymer consisting of polyisoprene backbone and hydrophilic side chain with carbamic acid ester functional group was prepared via thiol-ene＂click＂reaction and alcohol-isocyanate *** was synthesized by anionic polymerization using n-butyl lithium as initiator,and the pendant hydroxyl groups were introduced by the thiol-ene reaction of mercaptoethanol with the double bond of 1,2-addition units of PI backbone in the presence of radical initiator azobisisobutyronitrile. Isocyanate end group capped poly（ethylene glycol）（mPEG-NCO） was grafted onto the PI backbone through alcoholisocyanate reaction between the pendant hydroxyl groups and isocyanate group of *** structure of the graft copolymer were characterized and confirmed by means of size-exclusion chromatography,~1H NMR and FTIR spectroscopy.

关键词： Graft-copolymer Thiol-ene addition Isocyanate Click reaction

Polymerization of Methyl Methacrylate with Samarocene Complex Supported on Mesoporous Silica

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Chinese Chemical Letters 2001年第9期12卷 821-822页

作者： Xu Feng ni Zhi quan SHEN Hajime YASUDA Institute of Polymer Science Zhejiang UniversityHangzhou 310027 Department of Applied Chemistry Faculty of EngineeringHiroshima UniversityHigashi-Hiroshima 724Japan

Samarocene complex was supported on a series of mesoporous silica with various pore sizes. Polymerization of methyl methacrylate (MMA) by these catalysts provide highly syndiotactic PMMAs with higher molecular weights... 详细信息

关键词： Mesoporous silica supported catalyst samarocene complex

Self-assembled semiconductor quantum dots decorating the facets of GaAs nanowire for single-photon emission

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National Science Review 2017年第2期4卷 196-209页

作者： Ying Yu guo-Wei Zha Xiang-Jun Shang Shuang Yang Ban-quan Sun Hai-Qiao ni Zhi-Chuan niu State Key laboratory for Superlattice and Microstructures Institute of SemiconductorsChinese Academy of Sciences State Key Laboratory of Optoelectronic Materials and Technologies School of electronics and information technologySun Yat-sen University College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences Synergetic Innovation Center of quantum Information& quantum Physics University of Science and Technology of China

In this chapter, we discuss the epitaxial growth of self-assembled quantum dots(QDs) in GaAs nanowires(NWs) and the characteristics of their single-photon emissions. We demonstrate Ga droplet-induced gold-free vapor-liquid-solid growth of hexagonal GaAs/Al GaAs core–shell NWs, branched GaAs NWs and tailored nanostructured morphologies on the NW facets. Particularly, we show two new types of QD-in-NW systems: one is a single InAs QD formed at the corner of a branched GaAs NW, and the other is a single GaAs QD formed on the NW facet. Sharp excitonic emission spectral lines are observed with vanishing two-photon emission probability. Furthermore, a single GaAs QD is achieved at the site of a single Al GaAs quantum ring(QR) on the NW facet. In addition, these NW-based single QDs are in-situ probed and integrated with single-mode optical ibers to achieve all-iber-output single-photon sources for potential application in quantum integrated networks.

关键词： self-assembled nanowires quantum dots single photon emitters molecular beam epitaxy

Mechanism of Janus Polymerization: A DFT StudyFig. S3 Energy profiles of anionic polymerization in Stage I under B3LYP/6-31G(d,p)(blue) and B3LYP/aug-cc-p VTZ//B3LYP/6-31G(d,p)(red). Scheme S1. Propagation process of CL/THF on cationic side in Stage I of J

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Chinese Journal of Polymer Science 2019年第10期37卷 990-994,I0004页

作者： Tian-Wen Bai Xu-Feng ni Jun Ling Zhi-quan Shen Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Janus polymerization is featured as a combination of cationic and anionic growing ends in one living polymer chain. In the copolymerization of THF and CL catalyzed by lutetium triflates and initiated by propylene oxide, three stages are identified by kinetic study including(1) fast cationic polymerization with slow anionic one,(2) fast anionic polymerization with dormant cationic one, and(3)reactivation of cationic polymerization with coupling of anionic and cationic chain ends. In this work, density functional theory(DFT)calculation is employed to investigate the reaction details of ionic polymerization and dormancy. A “tripedal crow” configuration is proposed to illustrate the unique high-coordinated ligand exchange configuration in anionic polymerization in different stages. The trigger of dormancy is determined as chain structures rather than concentration of triflate anion according to both calculation and experimental results.

关键词： Rare earth metal catalysts Ring-opening polymerization Ionic polymerization Reaction mechanism quantum chemicalcomputation

A perspective on the electrocatalytic conversion of carbon dioxide to methanol with metallomacrocyclic catalysts

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Journal of Energy Chemistry 2022年第1期31卷 263-275,I0008页

作者： Xinyan Liu Bo-quan Li Bing ni Lei Wang Hong-Jie Peng Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Physical Chemistry Department of ChemistryUniversity of KonstanzUniversitatsstrasse 10D-78457 KonstanzGermany Department of Chemical and Biomolecular Engineering National University of Singapore.Singapore 117585Singapore

Electrocatalytic carb on dioxide reducti on(CO_(2)R)presents a promising route to establish zero-e mission carb on cycle and store in termittent ren ewable energy into chemical fuels for steady energy *** is an ideal energy carrier as alternative fuels and one of the most important commodity ***,methanol is currently mainly produced from fossil-based syngas,the production of which yields tremendous carb on emission *** CO_(2)R towards metha nol poses great potential to shift the paradigm of methanol *** this perspective,we focus our discussions on producing methanol from electrochemical CO_(2)R,using metallomacrocyclic molecules as the model *** discuss the motivation of having methanol as the sole CO_(2)R product,the documented application of metallomacrocyclic catalysts for CO_(2)R,and recent advance in catalyzing CO_(2) to methanol with cobalt phthalocyanine-based *** attempt to understand the key factors in determining the activity,selectivity,and stability of electrocatalytic CO_(2)-to-methanol conversion,and to draw mechanistic insights from existing ***,we identify the challenges hindering methanol electrosynthesis directly from CO_(2) and some intriguing directions worthy of further investigation and exploration.

关键词： Carbon dioxide reduction Methanol Electrocatalysis Molecular catalysts Single atom catalysts Heterogenization

Markov Jump Processes in Estimating Sharing of Identity by Descent

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Acta Mathematicae Applicatae Sinica 2021年第1期37卷 183-191页

作者： Xian CHEN Wei guo Xu-min ni School of Mathematical Sciences Xiamen UniversityXiamen 361005China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044China

Identity by descent(IBD)sharing is a very important genomic feature in population genetics which can be used to reconstruct recent demographic *** this paper we provide a framework to estimate IBD sharing for a demographic model called two-population model with *** adopt the structured coalescent theory and use a continuous-time Markov jump process{X(t),t≥0}to describe the genealogical process in such *** we apply Kolmogorov backward equation to calculate the distribution of coalescence time and develop a formula for estimating the IBD *** simulation studies show that our method to estimate IBD sharing for this demographic model is robust and accurate.

关键词： IBD sharing structured coalescent theory Markov jump process Kolmogorov backward equation

Nonreciprocal metasurface with space-time phase modulation

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Light(Science & Applications) 2019年第1期8卷 30-38页

作者： Xuexue guo Yimin Ding Yao Duan Xingjie ni Department of Electrical Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA

Creating materials with time-variant properties is critical for breaking reciprocity that imposes fundamental limitations on wave ***,it is challenging to realize efficient and ultrafast temporal modulation in a photonic ***,leveraging both spatial and temporal phase manipulation offered by an ultrathin nonlinear metasurface,we experimentally demonstrated nonreciprocal light reflection at wavelengths around 860 *** metasurface,with travelling-wave modulation upon nonlinear Kerr building blocks,creates spatial phase gradient and multi-terahertz temporal phase wobbling,which leads to unidirectional photonic transitions in both the momentum and energy *** observed completely asymmetric reflections in forward and backward light propagations over a large bandwidth around 5.77 THz within a sub-wavelength interaction length of 150 *** approach highlights a potential means for creating miniaturized and integratable nonreciprocal optical components.

关键词： reciprocal phase nonlinear

Preparation of CuInSe_2 thin films by paste coating

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Rare Metals 2008年第6期27卷 591-597页

作者： niE Hongbo WANG Yanlai ni Peiran guo Shiju School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China WuxiASICMicro Electronics Co. Ltd Wuxi 214028 China

Precursor pastes were obtained by milling Cu-In alloys and Se powders. CulnSe2 thin films were successfully prepared by precursor layers, which were coated using these pastes, and were annealed in a H2 atmosphere. The pastes were tested by laser particle diameter analyzer, simultaneous thermogravimetric and differential thermal analysis instruments （TG-DTA）, and X-ray diffractometry （XRD）. Selenized films were characterized by XRD, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises. All the CuInSe2 thin films, which were annealed at various temperatures, exhibit the preferred orientation along the （112） plane. The compression of precursor layers before selenization step is one of the most essential factors for the preparation of perfect CuInSe2 thin films.

关键词： inorganic non-metal material CulnSe2 thin films selenization coating Cu-In alloys

The first excited single-proton resonance in 15F by complex-scaled Green's function method

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Chinese Physics C 2020年第5期44卷 63-70页

作者： Xin-Xing Shi quan Liu Dong-Dong ni Jian-You guo Zhong-Zhou Ren School of Physics Nanjing UniversityNanjing 210093China School of physics and materials science Anhui UniversityHefei 230601China Space Science Institute Macao University of Science and TechnologyMacaoChina School of Physics Science and Engineering Tongji UniversityShanghai 200092China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

The complex-scaled Green's function(CGF)method is employed to explore the single-proton resonance in *** attention is paid to the first excited resonant state 5/2+,which has been widely studied in both theory and ***,past studies generally overestimated the width of the 5/2+*** predicted energy and width of the first excited resonant state 5/2+by the CGF method are both in good agreement with the experimental value and close to Fortune's new ***,the influence of the potential parameters and quadruple deformation effects on the resonant states are investigated in detail,which is helpful to the study of the shell structure evolution.

关键词： single-proton resonance complex-scaled Green's function method narrower width

Grain size distribution and topology in 3D grain growth simulation with large-scale Monte Carlo method

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International Journal of Minerals,Metallurgy and Materials 2009年第1期16卷 37-42页

作者： Hao Wang guo-quan Liu Xiang-ge Qin School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Jiamusi University Jiamusi 154007 China

Three-dimensional normal grain growth was appropriately simulated using a Potts model Monte Carlo algorithm. The quasi-stationary grain size distribution obtained from simulation agreed well with the experimental result of pure iron. The Weibull function with a parameter β=2.77 and the Yu-Liu function with a parameter v =2.71 fit the quasi-stationary grain size distribution well. The grain volume distribution is a function that decreased exponentially with increasing grain volume. The distribution of boundary area of grains has a peak at S/〈S〉=0.5, where S is the boundary area of a grain and 〈S〉 is the mean boundary area of all grains in the system. The lognormal function fits the face number distribution well and the peak of the face number distribution is f=10. The mean radius off-faced grains is not proportional to the face number, but appears to be related by a curve convex upward. In the 2D cross-section, both the perimeter law and the Aboav-Weaire law are observed to hold.

关键词： three-dimensional grain growth Monte Carlo simulation grain size distribution topology