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Chinese Journal of Polymer Science 2024年第6期42卷 826-837页

作者： Feng-Ming Yin Li-Li Wu Shu-Sheng Li xiao-Na Pan xiao-Li Zhu xu-Bao Jiang Xiang zheng Kong College of Chemistry and Chemical Engineering University of JinanJinan250022China Shandong Institute for Product Quality Inspection Jinan250102China College of Chemical Engineering Tianjin UniversityTianjin300072China

Non-aromatic fluorescent and multi-responsive materials,exhibiting inherent fluorescence emission and controlled phase change,have garnered significant attention in recent ***,the underlying interaction between their fluorescent properties and phase transition remains *** this study,we synthesized a series of catalyst-free aza-Michael addition-based polyethyleneimine(RFPEI)materials by reacting polyethyleneimine(PEI)with N-isopropyl acrylamide(NIPAM).The resulting RFPEI was comprehensively characterized,and demonstrated dual-phase transition behavior(LCST and UCST)in water,which could be finely tuned by adjusting its composition or external factors such as ***,upon UV irradiation(365 nm),RFPEI exhibited strong fluorescence *** further investigated the effects of NIPAM grafting percentage to PEI,polymer concentration,and pH on the LCST/UCST and fluorescent properties of RFPEI aqueous ***,we showcased the great potential of RFPEI as a versatile tool for physiological cell imaging,trace detection,and controlled release of *** study presents a novel class of stimuli-responsive fluorescent materials with promising applications in the field of biomedicine.

关键词： Polyethyleneimine Multi-responsiveness Intrinsic fluorescence emission Cell imaging Controlled drug release

Catalytic asymmetric dearomative azo-Diels–Alder reaction of 2-vinlyindoles

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Chinese Chemical Letters 2024年第4期35卷 357-362页

作者： Yu-Hang Miao zheng-xu Zhang xu-Yi Huang Yuan-Zhao Hua Shi-Kun Jia xiao xiao Min-Can Wang Li-Ping xu Guang-Jian Mei Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450052China School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000China Institute of Pharmaceutical Science and Technology Zhejiang University of TechnologyHangzhou 310014China

Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong background reaction and poses a daunting challenge to chemists for developing the catalytic asymmetric version. Reported herein is the first catalytic asymmetric dearomative azo-Diels–Alder reaction between2-vinylindoles and triazoledione. This protocol makes use of the high energy barrier of dearomatization to avert the strong background reaction of azo-Diels–Alder reaction, allowing the implementation of the projected reaction at ambient temperature. Density functional theory calculations have been performed to gain insights into the reaction mechanism and the origins of the enantioselectivity. By using this method,a variety of tetracyclic indole derivatives have been readily prepared in good to excellent yields and with excellent diastereo-and enantio–selectivities(33 examples, up to 97% yield and >99% ee, >20:1 dr).

关键词： Catalytic asymmetric dearomatization Azo-Diels–Alder reaction 2-Vinylindoles Chiral phosphoric acid Tetracyclic indole derivatives

Numerical investigation on dynamic response of the screen mesh in vibrating screening through DEM-FEM co-simulation

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Particuology 2024年第4期87卷 205-217页

作者： Huan Zhang xiao zheng Weimin Jing Key Laboratory of MetallurgicalEquipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081 China Hubei Key Laboratory of Mechanical Transmssion and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan430081China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing400044China

Dynamic response of the screen mesh is of great significance in the optimum vibrating screen *** this paper,based on the DEM-FEM co-simulation method,the effect of screening parameters on the dynamic response of the screen mesh is explored and the mechanism is revealed on the particle ***,a virtual experiment on a linear vibrating screen was carried out to analyze the screening pa-rameters'effect with both impact load and sustained stress inflicted on the screen ***,the time-domain evolution regularity of the screen mesh LVA(Local Vibration Amplitude)under different particle plugging conditions was investigated based on the ***,the influence of screening parameters on LVA and its distribution was *** results show that the screening parameters can greatly affect the screen mesh LVA and its distribution by changing the movement of the granular material and the particle penetration probability,which provides an important basis for the optimal design of the screen mesh and its supporting structure.

关键词： Vibrating screen Dynamic response DEM-FEM Screening parameters Local vibration amplitude

Multifunctional Film Assembled from N‑Doped Carbon Nanofiber with Co–N_(4)–O Single Atoms for Highly Efficient Electromagnetic Energy Attenuation

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Nano-Micro Letters 2024年第11期16卷 359-376页

作者： Jia xu Bei Li zheng Ma xiao Zhang Chunling Zhu Feng Yan Piaoping Yang Yujin Chen College of Materials Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001People’s Republic of China Key Laboratory of In‑Fiber Integrated Optics College of Physics and Optoelectronic EngineeringHarbin Engineering UniversityHarbin 150001People’s Republic of China

Single-atom materials have demonstrated attractive physicochemical ***,understanding the relationships between the coordination environment of single atoms and their properties at the atomic level remains a considerable ***,a facile waterassisted carbonization approach is developed to fabricate well-defined asymmetrically coordinated Co–N_(4)–O sites on biomass-derived carbon nanofiber(Co–N_(4)–O/NCF)for electromagnetic wave(EMW)*** such nanofiber,one atomically dispersed Co site is coordinated with four N atoms in the graphene basal plane and one oxygen atom in the axial ***-depth experimental and theoretical studies reveal that the axial Co–O coordination breaks the charge distribution symmetry in the planar porphyrin-like Co–N_(4) structure,leading to significantly enhanced dielectric polarization loss relevant to the planar Co–N_(4) ***,the film based on Co–N_(4)–O/NCF exhibits light weight,flexibility,excellent mechanical properties,great thermal insulating feature,and excellent EMW absorption with a reflection loss of−45.82 dB along with an effective absorption bandwidth of 4.8 *** findings of this work offer insight into the relationships between the single-atom coordination environment and the dielectric performance,and the proposed strategy can be extended toward the engineering of asymmetrically coordinated single atoms for various applications.

关键词： Co single atoms Asymmetric coordination structure Axial oxygen coordination Electromagnetic wave absorption Multifunctional film

A Trust Evaluation Mechanism Based on Autoencoder Clustering Algorithm for Edge Device Access of IoT

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Computers, Materials & Continua 2024年第2期78卷 1881-1895页

作者： xiao Feng zheng Yuan Cyber Security Academy Beijing University of Posts and TelecommunicationsBeijing100876China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China State Grid Info-Telecom Great Power Science and Technology Co. Ltd.Beijing102211China

First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction *** weight the time attenuation factor to each historical interaction record for updating and got the new historical record *** refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical *** we propose an autoencoder-based trust clustering *** perform feature extraction based on *** leibler(KL)divergence is used to calculate the reconstruction *** constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the *** sparse penalty term in the loss function measures the difference through the KL *** clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering *** the clustering process,edge nodes have a variety of trustworthy attribute *** assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of ***,we introduced adaptive weights to calculate comprehensive trust *** experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.

关键词： Cross-domain authentication trust evaluation autoencoder

A Single-Cell Landscape of Human Liver Transplantation Reveals a Pathogenic Immune Niche Associated with Early Allograft Dysfunction

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Engineering 2024年第5期36卷 193-208页

作者： Xin Shao zheng Wang Kai Wang xiaoyan Lu Ping Zhang Rongfang Guo Jie Liao Penghui Yang Shusen zheng xiao xu xiaohui Fan Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China National Key Laboratory of Chinese Medicine Modernization Innovation Center of Yangtze River DeltaZhejiang UniversityJiaxing 314103China Zhejiang University School of Medicine Hangzhou 310058China NHC Key Laboratory of Combined Multi-organ Transplantation Hangzhou 310003China Department of Hepatobiliary and Pancreatic Surgery Shulan(Hangzhou)Hospital Affiliated to Shulan International Medical CollegeZhejiang Shuren UniversityHangzhou 310000China Engineering Research Center of Innovative Anticancer Drugs Ministry of EducationHarbin 150023China

Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver *** notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of ***,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to ***,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion *** of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))***,we verified this immune niche and its association with EAD occurrence in two independent *** findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset.

关键词： Human liver transplantation Early allograft dysfunction Pathogenic immune niche Single-cell analysis Cell-cell communication

Metamorphic P-T conditions and ages of garnet-biotite schists in the Dahongshan Group from the southwestern Yangtze Block

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Acta Geochimica 2024年第4期43卷 707-718页

作者： Jun-xiao Ma Guang-shu Yang Yong-feng Yan xiao-Fei xu Yun-hua Ren Hui Zhao xiao-jun zheng Yuan Qin Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Geological Team 306 of Yunnan Non-Ferrous Metals Geological Bureau Kunming 650217China Yunnan Provincial Bureau of Non-Ferrous Geology Kunming 650051China

The Dahongshan Group,situated at the southwestern margin of the Yangtze Block,represents a geological unit characterized by relatively high-grade metamorphism in the *** paper investigates the garnet-biotite schist from the Laochanghe Formation of the Dahongshan Group,employing an integrated approach that includes petrological analysis,phase equilibrium modeling,and zircon U-Pb *** schist is mainly composed of garnet,biotite,plagioclase,quartz,rutile,and *** equilibrium modeling revealed the peak metamorphic conditions of 8-9 kbar and 635-675°*** further integrating the prograde metamorphic profile of garnet and geothermobarometric results,a clockwise P-T metamorphic evolution path is constructed,which includes an increase in temperature and pressure during the prograde ***-ICP-MS zircon U-Pb dating and zircon Ti thermometry constrains the post-peak metamorphic age of 831.2±7.2 *** with previously reported results,it is revealed that the southwestern margin of the Yangtze Block experienced a large-scale regional metamorphism during the Neoproterozoic(890-750 Ma),which is related to the collisional orogenic *** may be associated with the late-stage assembly of the Rodinia supercontinent or with local compression and subduction processes during the breakup of the Rodinia supercontinent.

关键词： Southwestern Yangtze Block Dahongshan Group Phase equilibrium modeling Zircon U-Pb dating Neoproterozoic metamorphism

Stretchable fiber strain sensors for wearable biomonitoring

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National Science Review 2024年第7期11卷 70-71页

作者： Shumao xu xiao xiao Jun Chen Department of Bioengineering University of California

Wearable bioelectronics have gained significant attention since they may play a role in transforming current healthcare from a reactive and disease-centric model to a personalized one with a focus on disease preventio...

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A survey on facial image deblurring

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Computational Visual Media 2024年第1期10卷 3-25页

作者： Bingnan Wang Fanjiang xu Quan zheng Institute of Software Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

When a facial image is blurred,it significantly affects high-level vision tasks such as face *** purpose of facial image deblurring is to recover a clear image from a blurry input image,which can improve the recognition accuracy,***,general deblurring methods do not perform well on facial ***,some face deblurring methods have been proposed to improve performance by adding semantic or structural information as specific priors according to the characteristics of the facial *** this paper,we survey and summarize recently published methods for facial image deblurring,most of which are based on deep ***,we provide a brief introduction to the modeling of image ***,we summarize face deblurring methods into two categories:model-based methods and deep learning-based ***,we summarize the datasets,loss functions,and performance evaluation metrics commonly used in the neural network training *** show the performance of classical methods on these datasets and metrics and provide a brief discussion on the differences between model-based and learning-based ***,we discuss the current challenges and possible future research directions.

关键词： facial image deblurring model-based deep learning-based semantic or structural prior

Challenges and opportunities in Quaternary palynology

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Science China Earth Sciences 2024年第7期67卷 2148-2161页

作者： Qinghai xu Houyuan LU Zhuo zheng College of Geographical Sciences Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth Sciences and Engineering Sun Yat-sen UniversityZhuhai 519082China

Quaternary palynology plays a pivotal role in investigating global climate change and various other research fields,serving as an essential tool for the quantitative analysis of paleoenvironment ***,due to the vast diversity of terrestrial ecosystems and intricate interactions between vegetation,climate,and human activities,further advancements are required in the following aspects within this discipline.(1)The accuracy of classification in pollen morphology and fossil pollen identification needs improvement,particularly at the species *** represents a significant challenge in present Quaternary ***-aided intelligent recognition holds promise as a solution for species identification based on more detail pollen morphology.(2)Most pollen-based vegetation and climate reconstructions overlook the significance of bare *** bare ground can lead to substantial inaccuracies when quantitatively reconstructing past vegetation and climate.(3)While pollen records provide reliable information on paleoclimate changes,current quantitative climate reconstruction models heavily rely on modern pollen datasets derived from present-day vegetation disturbed more or less by human *** introduces bias and uncertainties into paleoclimate reconstruction.(4)Although pollen can serve as an indicator of human activities,accurately quantifying the intensity of human influence remains *** accurate identification of crop pollen,reconstructing reliable land cover/use data,and integrating multidisciplinary data may enhance the identification and quantification of signals related to human activity in pollen records.

关键词： Quaternary palynology Paleoclimate Paleovegetation Human activity