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Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： yi-Lang qin Ping Zhu Chen-Xi Ouyang Xia dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1,4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

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Enhancing the compatibility of the amyloid-dye hybrid nanostructure for improved photo-biocatalysis

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Journal of Energy Chemistry 2023年第3期78卷 430-437,I0012页

作者： Zhen dong yanying Wang qin yang Dan Li Peng Wu College of Chemistry Sichuan UniversityChengdu 610064SichuanChina Analytical&Testing Centre State Key Laboratory of Hydraulics and Mountain River EngineeringSichuan UniversityChengdu 610064SichuanChina College of Biomass Science and Engineering Sichuan UniversityChengdu 610064SichuanChina School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007HenanChina

Artificial photosynthesis is significant for renewable energy generation,sustainable development,and environmental ***-protein hybrids are promising for developing photosynthesis mimics(e.g.,photo-biocatalysis),but their performances are far lower than the plant photosystems,partially because of the incompatibility between dye and the protein matrix that limits excited state electron transfer of the included ***,using ThT-insulin amyloid assembly as a model system,we proposed that increasing the dye-protein compatibility could lead to the improved photo-biocatalytic performance.A ThT derivative,ThTPD,was designed with the same electron acceptor but extended π-conjugated donor *** integrated into the insulin amyloid,the extended π-conjugated donor structure allowed increased binding affinity and energy with the amyloid matrix,thus better electron transport to the mediator to drive the photocatalytic ***,compared with ThT, ThTPD exhibited improved light absorption and longer excited state *** photo-biocatalytic performance of ThTPD-insulin amyloid was greatly improved as compared with that of ThT in reduced nicotinamide adenine dinucleotide(NADH) *** integrating with NADH-dependent L-glutamate reductase,the efficiency of the ThTPD-insulin amyloid hybrid was 2.8-fold higher than that of ThT in glutamate generation,showing promising feature in biocatalytic solar-to-chemical conversion.

关键词： Photo-biocatalysis Dye-protein assembly Insulin amyloid ThT Compatibility

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Growth regularity and phase diagrams of NaLu_(0.795−x)y_(x)F_(4) upconversion nanocrystals synthesized by automatic nanomaterial synthesizer

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Nano Research 2021年第12期14卷 4760-4767页

作者： Dan Zhang yanhui dong Daguang Li Heng Jia Weiping qin State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun130012China

The growth regularities of nanomaterials are often concealed by the contingency of preparation. Therefore, it is always very difficult to figure out growth regularities of nanomaterials due to the accompanying undulation of products. A series of precise synthesis was performed by using an automatic nanomaterial synthesizer (ANS) in order to explore the growth regularity of complex NaREF4 (RE: rare earth) upconversion nanocrystals (UCNCs). The use of ANS significantly enhances the experimental controllability, repeatability, and success rate. Mass experimental research exhibited that the NaLu_(0.795−x)y_(x)F_(4):yb^(3+)/Tm^(3+) (x = 0−0.795) UCNCs can vary their sizes continuously in a wide range to accurately meet the experimenter’s design merely by controlling the concentration of y^(3+). A notable growth regularity was obtained and intuitively shown in growth phase diagrams. Furthermore, in the case of having excellent monodispersity, pure hexagonal phase, and uniform morphology, the prepared UCNCs still retained superior upconversion luminescent (UCL) properties. The regular changes in UCL properties further confirmed the growth regularity of the UCNCs. After analyzing the experimental data, we found that NaLu_(0.795−x)y_(x)F_(4) combined the advantages of NayF_(4) and NaLuF_(4) hosts with desired sizes. These results provide a guidance for the exploration of growth regularities of other similar nanomaterials and also for the structure design of the required nanomaterials.

关键词： NaLu_(0.795−x)y_(x)F_(4) upconversion nanocrystal growth regularity phase diagram automatic nanomaterial synthesizer

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Surface Characterization and Tribology Behavior of PMMA Processed by Excimer Laser

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Chinese Journal of Mechanical Engineering 2023年第5期36卷 45-61页

作者： dong qin Juan Guo Ming Liang Ling Chen Weimin He Department of Ophthalmology West China HospitalSichuan UniversityChengdu 610000China Ophthalmology Department The Third People’s Hospital of ChengduChengdu 610031China

Polyoxymethylene methacrylate (PMMA) is widely used in ophthalmic biomaterials. Misuse of PMMA in extreme environments is likely to damage the ocular surface and intraocular structures. The surface characterization and tribological behavior of PMMA processed using an excimer laser were investigated in this study by contrasting diferent lubrication conditions and friction cycles. The results show that the roughness of the material surface increases with laser processing, which changes its physical structure. Under lubrication, the laser-treated PMMA exhibits better hydrophilicity, especially during the use of eye drops. No obvious relationship exists between the laser-processing time and friction behavior. However, the laser treatment may contribute to the formation of friction and wear mechanisms of PMMA materials. Laser-treated PMMA in saline solution exhibits better abrasive resistance by showing a lower wear rate than that in eye drops, although it has a higher friction coefcient. In this study, the diferent friction stages in laser-treated PMMA were clarifed under two lubrication conditions. The wear rates of the laser-treated PMMA were found to decrease with the number of cycles, and the friction coefcient has a similar variation tendency. The wear behavior of the laser-treated PMMA is dominated by the main abrasive wear and secondary transferred flm formation. This study provides a theoretical basis for the development and application of ophthalmic biomaterials in complex environments by examining the material surface interface behavior and wear mechanism after laser processing using PMMA as the research matrix.

关键词： Biocompatible materials Poly(methyl methacrylate) Surface characterization Tribology behavior

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Efficient and High-quality Recommendations via Momentum-incorporated Parallel Stochastic Gradient Descent-Based Learning

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IEEE/CAA Journal of Automatica Sinica 2021年第2期8卷 402-411页

作者： Xin Luo Wen qin Ani dong Khaled Sedraoui MengChu Zhou the School of Computer Science and Technology Dongguan University of TechnologyDongguan 523808 Hengrui(Chongqing)Artificial Intelligence Research Center Department of Big Data Analyses TechniquesCloudwalkChongqing 401331China the School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing 400065 Chongqing Engineering Research Center of Big Data Application for Smart Cities Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China the Department of Computer and Information Science City College of Dongguan University of TechnologyDongguan 523419China the Department of Electrical and Computer Engineering Faculty of Engineeringand Center of Research Excellence in Renewable Energy and Power SystemsKing Abdulaziz UniversityJeddah 21481Saudi Arabia the Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewarkNJ 07102 USA the Center of Research Excellence in Renewable Energy and Power Systems King Abdulaziz UniversityJeddah 21481Saudi Arabia

A recommender system(RS)relying on latent factor analysis usually adopts stochastic gradient descent(SGD)as its learning ***,owing to its serial mechanism,an SGD algorithm suffers from low efficiency and scalability when handling large-scale industrial *** at addressing this issue,this study proposes a momentum-incorporated parallel stochastic gradient descent(MPSGD)algorithm,whose main idea is two-fold:a)implementing parallelization via a novel datasplitting strategy,and b)accelerating convergence rate by integrating momentum effects into its training *** it,an MPSGD-based latent factor(MLF)model is achieved,which is capable of performing efficient and high-quality *** results on four high-dimensional and sparse matrices generated by industrial RS indicate that owing to an MPSGD algorithm,an MLF model outperforms the existing state-of-the-art ones in both computational efficiency and scalability.

关键词： Big data industrial application industrial data latent factor analysis machine learning parallel algorithm recommender system(RS) stochastic gradient descent(SGD)

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The Nanoscale Density Gradient as a Structural Stabilizer for Glass Formation

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Engineering 2023年第10期29卷 120-129页

作者： Shaoxiong Zhou Bangshao dong yanguo Wang Jingyu qin Weihua Wang China Iron and Steel Research Institute Group Beijing 100081China Institute of Advanced Materials North China Electric Power UniversityBeijing 102206China Jiangsu JITRI Advanced Energy and Materials Research Institute Changzhou 213032China Beijing National Laboratory of Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China

The rapid cooling of a metallic liquid(ML)results in short-range order(SRO)among the atomic arrangements and a disordered structure in the resulting metallic glass(MG).These phenomena cause various possible features in the microscopic structure of the MG,presenting a puzzle about the nature of the MGs’microscopic structure beyond *** this study,the nanoscale density gradient(NDG)originating from a sequential arrangement of clusters with different atomic packing densities(APDs),representing the medium-range structural heterogeneity in Zr_(60)Cu_(30)Al_(10)MG,was characterized using electron tomography(ET)combined with image simulations based on structure *** coarse polyhedrons with distinct facets identified in the three-dimensional images coincide with icosahedron-like clusters and represent the spatial positions of clusters with high *** of the different clusters according to descending APD order in the glass-forming process are responsible for the NDG that stabilizes both the supercooled ML and the amorphous states and acts as a hidden rule in the transition from ML to MG.

关键词： Rapid cooling Amorphous solid Density gradient Electron tomography Atomic clusters

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Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO_(2)Molecules Enhances CO_(2)Photoreduction

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Research 2024年第2期2023卷 763-771页

作者： qin Ren ye He Hong Wang yanjuan Sun Fan dong Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China

Photocatalytic reduction of CO_(2)into fuels provides a prospective tactic for regulating the global carbon balance utilizing renewable solar ***,CO_(2)molecules are difficult to activate and reduce due to the thermodynamic stability and chemical *** this work,we develop a novel strategy to promote the adsorption and activation of CO_(2)molecules via the rapid energy exchange between the photoinduced Br vacancies and CO_(2)*** in situ continuous wave-electron paramagnetic resonance(cw-EPR)and pulsed EPR technologies,we observe that the spin-spin relaxation time(T_(2))of BiOBr is decreased by 198 ns during the CO_(2)photoreduction reaction,which is further confirmed by the broadened EPR *** result reveals that there is an energy exchange interaction between in situ formed Br vacancies and CO_(2)molecules,which promotes the formation of high-energy CO_(2)molecules to facilitate the subsequent reduction *** addition,theoretical calculations indicate that the bended CO_(2)adsorption configuration on the surface of BiOBr with Br vacancies caused the decrease of the lowest unoccupied molecular orbital of the CO_(2)molecule,which makes it easier for CO_(2)molecules to acquire electrons and get *** situ diffuse reflectance infrared Fourier transform spectroscopy further shows that the activated CO_(2)molecules are favorably converted to key intermediates of COOH*,resulting in a CO generation rate of 9.1μmol g^(-1)h^(-1)and a selectivity of 100%.This study elucidates the underlying mechanism of CO_(2)activation at active sites and deepens the understanding of CO_(2)photoreduction reaction.

关键词： reaction. adsorption activation

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A Cluster-Based Method for Marine Sensitive Object Extraction and Representation

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Journal of Ocean University of China 2015年第4期14卷 612-620页

作者： XUE Cunjin dong qing qin Lijuan Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences

Within the context of global change, marine sensitive factors or Marine Essential Climate Variables have been defined by many projects, and their sensitive spatial regions and time phases play significant roles in regional sea-air interactions and better understanding of their dynamic process. In this paper, we propose a cluster-based method for marine sensitive region extraction and representation. This method includes a kernel expansion algorithm for extracting marine sensitive regions, and a field-object triple form, integration of object-oriented and field-based model, for representing marine sensitive objects. Firstly, this method recognizes ENSO-related spatial patterns using empirical orthogonal decomposition of long term marine sensitive factors and correlation analysis with multiple ENSO index. The cluster kernel, defined by statistics of spatial patterns, is initialized to carry out spatial expansion and cluster mergence with spatial neighborhoods recursively, then all the related lattices with similar behavior are merged into marine sensitive regions. After this, the Field-object triple form of is used to represent the marine sensitive objects, both with the discrete object with a precise extend and boundary, and the continuous field with variations dependent on spatial locations. Finally, the marine sensitive objects about sea surface temperature are extracted, represented and analyzed as a case of study, which proves the effectiveness and the efficiency of the proposed method.

关键词： marine sensitive object kernel-based expansion Field-object model remote sensing images global change

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The Development of Khorgas Port in Xinjiang, China and Its Effect on Surrounding Towns

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Chinese Geographical Science 2023年第3期33卷 458-473页

作者： dong Junxi LIU Hanchu ZHAO yannan CHEN dong QIAO qin FAN Jie School of Economics and Management University of Chinese Academy of SciencesBeijing 100190China Institute of Science and Development Chinese Academy of SciencesBeijing 100190China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Chinese Research Academy of Environmental Sciences Institute of EcologyBeijing 100049China

The sustainable development of border port-cities is of considerable significance to the stabilization and consolidation of border areas,unlike coastal-ports cities that consist of coastal ports and *** ports should continue to drive the development of their surrounding towns to provide high-quality living conditions,employment,and housing for inhabitants of such towns and enhance the population agglomeration capacity of border *** study aimed to analyze the structure of employment and settlement in the cities surrounding the Khorgas Port at the different stages of its development—employing semi-structured interviews with individuals to analyze the spatial orientation characteristics of the daily needs of different groups of people and reveal the ways in which border ports drive the development of their surrounding towns—and recommend ways in which this can be *** study finds that as the Khorgas Port’s mutual trade market,industrial base,comprehensive management,and other functions continue to grow,the port is becoming increasingly *** more people work and settl in the surrounding towns,their living needs also ***,a considerable number of employed people do not live nearby,and many living needs are not being addressed in the towns surrounding the *** study also reveals the living services demands of government management personnel who work at the port on weekdays and return to yining City on weekends,employees of industrial enterprises who work at the port and return home for the New year’s celebration,and government management personnel and individual business personnel who work at the port and live *** the future,the focus should be on improving the living conditions of the inhabitants of the towns surrounding Khorgas Port,including public services and the settlement ability of employees of industrial enterprises to better realize the radiation drive of the port on the surrounding towns.

关键词： return services coastal

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WENO Interpolation-Based and Upwind-Biased Free-Stream Preserving Nonlinear Schemes

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Advances in Applied Mathematics and Mechanics 2021年第6期13卷 1441-1484页

作者： qin Li dong Sun Fengyuan Xu State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyangSichuan 621000China Key Laboratory of Aerodynamics Noise Control China Aerodynamics Research and Development CenterMianyangSichuan 621000China School of Aerospace Engineering Xiamen UniversityXiamenFujian 361102China

For flow simulations with complex geometries and structured grids,it is preferred for high-order difference schemes to achieve high *** order to achieve this goal,the satisfaction of free-stream preservation is necessary to reduce the numerical error in the numerical evaluation of grid *** the linear upwind schemes with flux splitting the free-stream preserving property has been achieved in the early study[*** et al.,***.,22(2017),pp.64–94].In the current paper,new series of nonlinear upwind-biased schemes through WENO interpolation will be *** the new nonlinear schemes,the shock-capturing capability on distorted grids is achieved,which is unavailable for the aforementioned linear upwind *** the inclusion of fluxes on the midpoints,the nonlinearity in the scheme is obtained through WENO interpolations,and the upwind-biased construction is acquired by choosing relevant grid *** third-and fifth-order nonlinear schemes are developed and *** are made among proposed schemes,alternative formulations of WENO and hybrid WCNS,in which a general formulation of center scheme with midpoint and nodes employed is obtained as a *** the numerical tests,the proposed schemes can achieve the designed orders of accuracy and free-stream preservation *** 1-D Sod and Shu-Osher problems,the results are consistent with the theoretical *** 2-D cases,the vortex preservation,supersonic inviscid flow around cylinder at M¥=4,Riemann problem,and shock-vortex interaction problems have been *** specifically,two types of grids are employed,i.e.,the uniform/smooth grids and the randomized/locally-randomized *** schemes can get satisfactory results in uniform/smooth *** the randomized grids,most schemes have accomplished computations with reasonable accuracy,except the failure of one third-order scheme in Riemann problem and shock-vortex ***,the proposed nonlinear

关键词： High-order difference scheme upwind-biased scheme WENO interpolation freestream preservation hybrid WCNS

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