检索结果-南通市图书馆

Host-guest interaction tailored cucurbit[6]uril-based supramolecular organic frameworks(SOFs) for drug delivery

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第3期33卷 1529-1532页

作者： Chun Liu Yu Xia Zhu Tao Xin-Long Ni Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province Guizhou UniversityGuiyang 550025China College of Chemistry and Chemical Engineering Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceHunan Normal UniversityChangsha 410081China

An approach for the construction of crystalline porous supramolecular organic frameworks (SOFs) via outer-surface interactions of cucurbit[6]uril (Q[6]) with high yield is presented. This approach enables the noncovalent integration of guest molecules into ordered topologies and creates new host-guest-complex-based SOFs;i.e., the topology can be predesigned and constructed by using [ZnCl_(4)]^(2-) anions to induce the formation of solid Q[6]-SOFs, and the pore wall surface can be easily modified by the Q[6]-encapsulated guest molecules. In addition, one of prepared solid Q[6]-SOFs showed a high drug-loading capacity and smart potential release control for drug-delivery applications.

关键词： Cucurbituril SOFs Porous materials Host-guest interaction Drug delievery

Adaptive Optimal Discrete-Time Output-Feedback Using an Internal Model Principle and Adaptive Dynamic Programming

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 131-140页

作者： Zhongyang Wang Youqing Wang Zdzisław Kowalczuk the College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China IEEE the Department of Robotics and Decision Systems Faculty of ElectronicsTelecommunications and InformaticsGdańsk University of TechnologyGdansk 80-233Poland

In order to address the output feedback issue for linear discrete-time systems, this work suggests a brand-new adaptive dynamic programming(ADP) technique based on the internal model principle(IMP). The proposed method, termed as IMP-ADP, does not require complete state feedback-merely the measurement of input and output data. More specifically, based on the IMP, the output control problem can first be converted into a stabilization problem. We then design an observer to reproduce the full state of the system by measuring the inputs and outputs. Moreover, this technique includes both a policy iteration algorithm and a value iteration algorithm to determine the optimal feedback gain without using a dynamic system model. It is important that with this concept one does not need to solve the regulator equation. Finally, this control method was tested on an inverter system of grid-connected LCLs to demonstrate that the proposed method provides the desired performance in terms of both tracking and disturbance rejection.

关键词： Adaptive dynamic programming(ADP) internal model principle(IMP) output feedback problem policy iteration(PI) value iteration(VI)

Regulating Anderson localization with structural defect disorder

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第10期33卷 102-107页

作者： Mouyang Cheng Haoxiang Chen Ji Chen School of Physics Peking UniversityBeijing 100871China Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials Peking UniversityBeijing 100871China Frontiers Science Center for Nano-Optoelectronics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

Localization due to disorder has been one of the most intriguing theoretical concepts that evolved in condensed matter ***,we expand the theory of localization by considering two types of disorders at the same time,namely,the original Anderson’s disorder and the structural defect disorder,which has been suggested to be a key component in recently discovered two-dimensional amorphous *** increasing the degree of both disorders could induce localization of wavefunction in real space,we find that a small degree of structural defect disorder can significantly enhance the *** the degree of structural defect disorder increases,localized states quickly appear within the extended phase to enter a broad crossover region with mixed *** establish two-dimensional diagrams for the wavefunction localization and conductivity to highlight the interplay between the two types of *** theoretical model provides a comprehensive understanding of localization in two-dimensional amorphous materials and highlights the promising tunability of their transport properties.

关键词： Anderson localization structural defect disorder electronic transport properties

Giant excitonic upconverted emission from two-dimensional semiconductor in doubly resonant plasmonic nanocavity

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第7期11卷 1523-1534页

作者： Pengfei Qi Yuchen Dai Yang Luo Guangyi Tao Liheng Zheng Donglin Liu Tianhao Zhang Jiadong Zhou Bo Shen Feng Lin Zheng Liu Zheyu Fang School of Physics State Key Laboratory for Mesoscopic PhysicsAcademy for Advanced Interdisciplinary StudiesCollaborative Innovation Center of Quantum MatterNano-optoelectronics Frontier Center of Ministry of EducationPeking UniversityBeijing 100871China Institute of Modern Optics Nankai UniversityTianjin Key Laboratory of Micro-scale Optical Information Science and TechnologyTianjin 300350China Photonics Research Center School of PhysicsMOE Key Lab of Weak-Light Nonlinear Photonicsand Tianjin Key Lab of Photonics Materials and Technology for Information ScienceNankai UniversityTianjin 300071China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

Phonon-assisted upconverted emission is the heart of energy harvesting,bioimaging,optical cryptography,and optical *** has been demonstrated that emerging two-dimensional(2D)semiconductors can provide an excellent platform for efficient phonon-assisted upconversion due to the enhanced optical transition strength and phonon-exciton interaction of 2D ***,there is little research on the further enhancement of excitonic upconverted emission in 2D ***,we report the enhanced multiphoton upconverted emission of 2D excitons in doubly resonant plasmonic *** to the enhanced light collection,enhanced excitation rate,and quantum efficiency enhancement arising from the Purcell effect,an upconverted emission amplification of>1000-fold and a decrease of 2~3 orders of magnitude in the saturated excitation power are *** findings pave the way for the development of excitonic upconversion lasing,nanoscopic thermometry,and sensing,revealing the possibility of optical refrigeration in future 2D electronic or excitonic devices.

关键词： converted resonant doubly

Theoretical Measurements of Quantitative Effects Caused by Spectator Ligands on Palladium-catalyzed C−H Activation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2022年第3期41卷 19-29,I0007页

作者： MA Xiao-Si ZHOU Yong-Zhu ZHANG Leia Department of Chemistry School of ScienceTianjin Chengjian UniversityTianjin 300384China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China

Ligands can definitely influence C−H activation at the metal center.A ligand not directly participating in the reaction is called a spectator *** attempt to quantitatively characterize the effects of diverse spectator ligands on C−H activation at *** designed a model palladium catalyst and selected an array of spectator ligands,such as methoxyl,amide,methyl,phenyl,cyanide,fluorine,chlorine,and several neutral ligands,and performed density functional theory calculations on the mechanism and energetics of C−H activation reactions of benzene with different *** ligands have substantially larger effects than neutral ligands,and stronglyσ-donating ligands(e.g.,methyl and phenyl)severely hinder the C−H activation in progress.A ligand trans to the reaction site influences C−H activation more than that cis to the reaction site,indicating electronic effects to be at *** example,the existence of a methyl ligand raises the barrier height of C−H activation by 6.4 or 14.4 kcal/mol when it is placed at the position cis or trans to the C−H activation *** effects of poorlyσ-donating ligands are not significant and similar to those of theκ1-acetate ***σ-donating andπ-accepting ligands,such as cyanide and isonitrile,hinder the C−H activation trans to them but appear to facilitate the C−H activation cis to *** the basis of molecular orbital analyses,a chemical model is proposed to understand the observed ligand ***,the conclusions are applied to explain the plausible mechanism of the dehydrogenative Heck coupling.

关键词： C−H activation ligand effect palladium catalyst reaction mechanism DFT calculation

Versatile photonic molecule switch in multimode microresonators

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 498-509页

作者： Zihan Tao Bitao Shen Wencan Li Luwen Xing Haoyu Wang Yichen Wu Yuansheng Tao Yan Zhou Yandong He Chao Peng Haowen Shu Xingjun Wang State Key Laboratory of Advanced Optical Communications System and Networks School of ElectronicsPeking UniversityBeijing 100871China College of Engineering Peking UniversityBeijing 100871China School of Integrated Circuits Peking University100871 BejingChina peking university Yangtze Delta Institute of Optoelectronics Nantong 226010China Frontiers Science Center for Nano-optoelectronics Peking UniversityBeijing 100871China Peng Cheng Laboratory Shenzhen 518055China

Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic ***,the distinct energy levels and interactions in such two-level systems were provided by coupled *** reconfigurability is limited,as they often require delicate external field stimuli or mechanically altering the geometric *** highly specific approaches also limit potential ***,we propose a versatile on-chip photonic molecule in a multimode microring,utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial *** transition between single/multi-mode states enables the“switched-off/on”functionality of the photonic molecule,supporting wider generalized applications *** particular,“switched-on”state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference,equivalent to the *** *** effect.“Switched-off”state allows for perfect low-loss single-mode transition(Qi~10 million)under an ultra-compact bend size(FSR~115 GHz)in a foundry-based silicon *** breaks the stereotyped image of the FSR-Q factor trade-off,enabling ultra-wideband and high-resolution millimeter-wave photonic *** demonstration provides a flexible and portable solution for the integrated photonic molecule system,extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.

关键词： switched multimode millimeter

Assembling high-Temperature Single-Molecule Magnets with Low-Coordinate Bis(amido)Dysprosium Unit[DyN_(2)]^(+)via Cl-K-Cl Linkage

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CCS Chemistry 2020年第5期2卷 362-368页

作者： Chen Wang Rong Sun Yaofeng Chen Bing-Wu Wang Zhe-Ming Wang Song Gao Beijing National Laboratory of Molecular Science Beijing Key Laboratory for Magnetoeletric Materials and DevicesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871(China) State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032(China) School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640(China)

Symmetryandaxialityarethought tobeguides toward the pursuit of high energy barrier and blocking temperature for thedysprosium(Ⅲ)(Dy^(Ⅲ))single-molecule magnets(SMMs).The Dy^(Ⅲ)complexeswith low coordination numbers are intended to satisfy axial ***,we report four four-coordinate Dy^(Ⅲ)SMMs based on bis(arylamido)dysprosium building block{Dy(N^(RR’))2(μ-Cl)_(2)K}(N^(RR’)={N(SiMe_(3))(C_(6)H_(3)iPr_(2)-2,6)}^(−)),with two strong Dy–N and twoweak Dy–Cl *** fine-tuning of axial anisotropy,the SMM with the largest N–Dy–N angle of 139.24(15)°displayed magnetic hysteresis with a coercive field(H_(c))of 18.6 kOe at 2 K,which kept opening up to 35 *** current susceptibility measurement showed that the relaxation energy barrier reached as high as 1578 K,which is among the highest reported Dy^(Ⅲ)*** initio calculations revealed strong anisotropy and crystal-field axiality of the compound,despite the low symmetry,and provided a synthetically workable approach to construct high-performance SMMs useful in applications such as digital processing,transport electronics,quantumcomputing,and ultra-high-density data storage.

关键词： low-coordinate strategy low symmetry bulky amido ligand magnetic anisotropy single-molecule magnets

Three-Phase Heterojunction NiMo-Based Nano-Needle for Water Splitting at Industrial Alkaline Condition

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第1期14卷 325-339页

作者： Guangfu Qian Jinli Chen Tianqi Yu Jiacheng Liu Lin Luo Shibin Yin College of Chemistry and Chemical Engineering State Key Laboratory of Processing for Non-Ferrous Metal and Featured MaterialsGuangxi University100 Daxue RoadNanning 530004People’s Republic of China

Constructing heterojunction is an effective strategy to develop high-performance non-preciousmetal-based catalysts for electrochemical water splitting(WS).Herein,we design and prepare an N-doped-carbon-encapsulated Ni/MoO_(2) nano-needle with three-phase heterojunction(Ni/MoO_(2)@CN)for accelerating the WS under industrial alkaline *** functional theory calculations reveal that the electrons are redistributed at the three-phase heterojunction interface,which optimizes the adsorption energy of H-and O-containing intermediates to obtain the best ΔG_(H*) for hydrogen evolution reaction(HER)and decrease the ΔG value of ratedetermining step for oxygen evolution reaction(OER),thus enhancing the HER/OER catalytic *** results confirm that Ni/MoO_(2)@CN exhibits good activity for HER(ƞ_(-10)=33 mV,ƞ_(-1000)=267 mV)and OER(ƞ_(10)=250 mV,ƞ_(1000)=420 mV).It shows a low potential of 1.86 V at 1000 mA cm^(−2) for WS in 6.0 M KOH solution at 60℃ and can steadily operate for 330 *** good HER/OER performance can be attributed to the three-phase heterojunction with high intrinsic activity and the self-supporting nano-needle with more active sites,faster mass diffusion,and bubbles *** work provides a unique idea for designing high efficiency catalytic materials for WS.

关键词： Three-phase heterojunction Interfacial electronic redistribution Catalyst Large current density Water splitting

Towards quantitative determination of atomic structures of amorphous materials in three dimensions

在线全文

学校读者我要写书评

暂无评论

National Science Open 2023年第3期2卷 1-26页

作者： Zhiheng Xie Yao Zhang Siwei Huang Zezhou Li Qi Cheng Jihan Zhou Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Amorphous materials such as glass,polymer and amorphous alloy have broad applications ranging from daily life to extreme conditions due to their unique properties in elasticity,strength and electrical resistivity.A better understanding of atomic structure of amorphous materials will provide invaluable information for their further engineering and ***,experimentally determining the three-dimensional(3D)atomic structure of amorphous materials has been a long-standing *** to the disordered atomic arrangement,amorphous materials do not have any translational and rotational symmetry at long-range *** characterization methods,such as the scattering and the microscopy imaging,can only provide the statistic structural information which is averaged over the macroscopic *** knowledge of the 3D atomic structure of amorphous materials is *** atomic resolution electron tomography(AET)has proven an increasingly powerful tool for atomic scale structural characterization without any crystalline assumptions,which opens a door to determine the 3D structure of various amorphous *** this review,we summarize the state-of-art characterization methods for the exploration of atomic structures of amorphous materials in the past few decades,including X-ray/neutron diffraction,nano-beam and angstrom-beam electron diffraction,fluctuation electron microscopy,high-resolution scanning/transmission electron microscopy,and atom probe *** experimental data and theoretical descriptions,3D structures of various amorphous materials have been built ***,we introduce the principles and recent progress of AET,and highlight the most recent groundbreaking feat accomplished by AET,i.e.,the first experimental determination of all 3D atomic positions in a multi-component glass-forming alloy and the 3D atomic packing in amorphous *** also discuss the new opportunities and challenges for characterizing the chemical

关键词： amorphous solid atomic structure 3D reconstruction atomic resolution electron tomography short-range order medium-range order