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Selective C-C bonds formation,N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite

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Chinese Chemical Letters 2022年第1期33卷 266-270页

作者： Guanxin Zhu zheng-chao duan Haiyan Zhu Dongdong Ye Dawei Wang The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China School of Chemical and Environmental Engineering Hubei Minzu UniversityEnshi 445000China

Earth abundant metals are much less expensive,promising,valuable metals and could be served as catalysts for the borrowing hydrogen reaction,dehydrogenation and heterocycles synthesis,instead of noble *** uniformly dispersed zinc composites were designed,synthesized and carefully characterized by means of XPS,EDS,TEM and *** resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines,ketones with alcohols in water under base-free conditions,while unsaturated carbonyl compounds could also be synthesized by tuning the reaction ***,it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green ***,this zinc catalyst could be easily recovered and reused for at least five times.

关键词： Unsymmetrical Zinc Borrowing hydrogen Recyclability Selective

Facile synthesis of novel fluorinated thieno[2,3-d]pyrimidine derivatives containing 1,3,4-thiadiazole

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Chinese Chemical Letters 2012年第5期23卷 549-552页

作者： Xin Jian Song zheng chao duan Yu Shao Xing Gao Dong Key Laboratory of Biological Resources Protection and Utilization of Hubei Province Hubei University for NationalitiesEnshi 445000China Medical School Hubei University for NationalitiesEnshi 445000China

A series of novel fluorinated thieno[2,3-d]pyrimidine derivatives incorporating 1,3,4-thiadiazole were synthesized by a facile microwave-assisted procedure,including the cyclization of 2-aminothiophene-3-carbonitrile with trifluoroacetic acid,chlorination and nucleophilic substitution *** protocol offered such advantages as mild reaction conditions,short reaction time, simple puritication and good *** structures of the products were characterized by ~1H NMR,MS,elemental analysis and Xray diffraction.

关键词： Thieno[2.3-d]pyrimidine 1 3 4-Thiadiazole Trifluoromethyl Microwave-assisted synthesis

Joint Sample Position Based Noise Filtering and Mean Shift Clustering for Imbalanced Classification Learning

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Tsinghua Science and Technology 2024年第1期29卷 216-231页

作者： Lilong duan Wei Xue Jun Huang Xiao zheng School of Computer Science and Technology Anhui University of TechnologyMaanshan 243032China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China

The problem of imbalanced data classification learning has received much *** classification algorithms are susceptible to data skew to favor majority samples and ignore minority *** weighted minority oversampling technique(MWMOTE)is an effective approach to solve this problem,however,it may suffer from the shortcomings of inadequate noise filtering and synthesizing the same samples as the original minority *** this end,we propose an improved MWMOTE method named joint sample position based noise filtering and mean shift clustering(SPMSC)to solve these ***,in order to effectively eliminate the effect of noisy samples,SPMsC uses a new noise filtering mechanism to determine whether a minority sample is noisy or not based on its position and distribution relative to the majority *** that MWMOTE may generate duplicate samples,we then employ the mean shift algorithm to cluster minority samples to reduce synthetic replicate ***,data cleaning is performed on the processed data to further eliminate class *** on extensive benchmark datasets demonstrate the effectiveness of SPMsC compared with other sampling methods.

关键词： imbalanced data classification oversampling noise filtering clustering

UAV swarm air combat maneuver decision-making method based on multi-agent reinforcement learning and transferring

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Science China(Information Sciences) 2024年第8期67卷 49-66页

作者： Zhiqiang zheng Chen WEI Haibin duan State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical Engineering Beihang University

During short-range air combat involving unmanned aircraft vehicle(UAV) swarms, UAVs must make accurate maneuver decisions based on information from both enemy and friendly UAVs. This dual requirement of competition and cooperation presents a significant challenge in the field of unmanned air combat. In this paper, a method based on multi-agent reinforcement learning(MARL) is proposed to address this issue. An actor network containing three subnetworks that can handle different types of situational information is designed. Hence, the results from simpler one-on-one scenarios are leveraged to enhance the complex swarm air combat training process. Separate state spaces for local and global information are designed for the actor and critic networks. A detailed reward function is proposed to encourage *** prevent lazy participants in air combat, a reward assignment operation is applied to distribute these dense rewards. Simulation testing and ablation experiments demonstrate that both the transfer operation and reward assignment operation can effectively deal with the swarm air combat scenario, and reflect the effectiveness of the proposed method.

关键词： multi-agent reinforcement learning reward assignment short-range air combat transfer UAV swarm

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Synergistic effects and kinetics analysis for co-pyrolysis of vacuum residue and plastics

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 71-81页

作者： chao Wang Xiaogang Shi Aijun duan Xingying Lan Jinsen Gao Qingang Xiong State Key Laboratory of Heavy Oil Processing China University of Petroleum-BeijingBeijing 102249China State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China

This study utilizedathermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue(VR)and low-density polyethylene(LDPE)*** kinetic parameters were calculated using the Friedman *** demonstrate the interactive effects between LDPE and VR during the co-pyrolysis process,the disparity in mass loss and mass loss rate between the experimental and calculated values was *** co-pyrolysis curves obtained through estimation and experimentation exhibited significantdeviations,whichwerei influencedby temperature and mixing ratio.A negative synergistic interaction was observed between LDPE and VR,although this inhibitory effect could be mitigated or eliminated by reducing the LDPE ratio in the mixture and increasing the ***-pyrolysisprocess resulted in a reduction in carbon residue,which could be attributed to the interaction between LDPE and the heavy fractions,particularly resin and asphaltene,present in *** findings align with the pyrolysis behaviors exhibited by the four VR ***,it was observed that the co-pyrolysis process exhibited lower activation energy as the VR ratio increased,indicating a continuous enhancement in the reactivity of the mixed samples during co-pyrolysis.

关键词： co-pyrolysis heavy residual oil polyethylene thermogravimetric analysis synergistic effects

Insights into the history and tendency of glycosylation and digestive system tumor:A bibliometric-based visual analysis

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 1059-1075页

作者： Jie Jiang Zai Luo Ren-chao Zhang Yue-Ling Wang Jun Zhang Ming-Yu duan zheng-Jun Qiu Chen Huang Department of Gastrointestinal Surgery Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200080China Jiangnan University Wuxi School of Medicine Wuxi 214122Jiangsu ProvinceChina Department of Education Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200080China

BACKGROUND Glycosylation,a commonly occurring post-translational modification,is highly expressed in several tumors,specifically in those of the digestive system,and plays a role in various cellular pathophysiological *** the importance and detection methods of glycosylation in digestive system tumors have garnered increasing attention in recent years,bibliometric analysis of this field remains *** present study aims to identify the developmental trends and research hotspots of glycosylation in digestive system *** To find and identify the developmental trends and research hotspots of glycosylation in digestive system *** We obtained relevant literature from the Web of Science Core Collection and employed VOSviewer 1.6.19 and CiteSpace(version 6.1.R6)to perform bibliometric *** A total of 2042 documents spanning from 1978 to the present were analyzed,with the research process divided into three phases:the period of obscurity(1978-1990),continuous development period(1991-2006),and the rapid outbreak period(2007-2023).These documents were authored by researchers from 66 countries or regions,with the United States and China leading in terms of publication *** Celso A had the highest number of publications,while Pinho SS was the most cited ***-occurrence analysis revealed the most popular keywords in this field are glycosylation,expression,cancer,colorectal cancer,and pancreatic ***,the Journal of Proteome Research was the most prolific journal in terms of publications,while the Journal of Biological Chemistry had the most *** The bibliometric analysis shows current research focus is primarily on basic research in this ***,future research should aim to utilize glycosylation as a target for treating tumor patients.

关键词： Glycosylation Cancer Digestive system Bibliometric analysis CiteSpace VOS viewer

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

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National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing Ma Linlin duan Yuzhu Ma Wei Zhang Changlin zheng Dongliang chao Fei Wang Yongyao Xia Wei Li Department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University State Key Laboratory of Surface Physics and Department of Physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable ***,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as *** key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon *** mesoporous Li2TiSiO5anode achieves a superior rate capability(148 mAh g-1at5.0 A g-1) and outstanding long-term cycling stability(138 mAh g-1after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-10 nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion *** method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

Upconverting and downshifting circularly polarized luminescence in a superstructural helix

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Science China Chemistry 2024年第8期67卷 2571-2577页

作者： Honghan Ji Bin Wu Enquan Tian chao Ren Xue Jin Liangliang Zhu Pengfei duan CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology(NCNST)Beijing 100190China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China University of Chinese Academy of Sciences Beijing 101408China

The modulation of circularly polarized luminescence(CPL) has become an increasingly prominent area of research. In this study,we propose a unique “one-excitation-to-three-emissions” CPL system through the co-assembly of an upconversion system,incorporating one sensitizer(Pt(II) mesotetraphenyl tetrabenzoporphyrine, Pt TPBP) and two annihilators(R/S-DPA and R/SBDP) within liquid crystals. The chiral nature of the annihilators induces a transformation of the nematic liquid crystal into chiral nematic liquid crystals(N*LC), establishing an excellent chiral matrix. Upon the incorporation of the sensitizer Pt TPBP and subsequent excitation at 635 nm, the system demonstrates two independent triplet–triplet annihilation photon upconversion(TTA-UC) with the emission in blue and yellow, aided by thermally activated triplet–triplet energy transfer(TTET). This is accompanied by the simultaneous generation of upconverting circularly polarized luminescence(UC-CPL) and downshifting near-infrared circularly polarized luminescence(DS-CPL) originating from the residual luminescence of Pt TPBP. Remarkably,fine-tuning the ratio between the two annihilators allows the TTA-UC system to exhibit multicolor CPL emission with an amplified luminescence dissymmetry factor(glum, reaching up to 0.6). Our study unveils a previously unreported “one-excitation-to-three-emissions” system and provides a versatile strategy for modulating CPL emissions, surpassing conventional methodologies.

关键词： circularly polarized luminescence triplet–triplet annihilation upconversion near-infrared emission chiral nematic liquid crystal luminescence dissymmetry factor

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Porous nanocomposites with enhanced intrinsic piezoresistive sensitivity for bioinspired multimodal tactile sensors

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Microsystems & Nanoengineering 2024年第1期10卷 243-256页

作者： Jianpeng Zhang Song Wei Caichao Liu chao Shang Zhaoqiang He Yu duan zhengchun Peng State Key Laboratory of Radio Frequency Heterogeneous Integration(Shenzhen University) School of Physics and Optoelectronic EngineeringShenzhen University518060 ShenzhenGuangdong ProvinceP.R.China Linksense Technology Ltd. 518060 ShenzhenGuangdong ProvinceP.R.China

In this work,we propose porous fluororubber/thermoplastic urethane nanocomposites(PFTNs)and explore their intrinsic piezoresistive sensitivity to *** experiments reveal that the intrinsic sensitivity of the PFTN-based sensor to pressure up to 10 kPa increases up to 900%compared to the porous thermoplastic urethane nanocomposite(PTN)counterpart and up to 275%compared to the porous fluororubber nanocomposite(PFN)*** pressures exceeding 10 kPa,the resistance-pressure relationship of PFTN follows a logarithmic function,and the sensitivity is 221%and 125%higher than that of PTN and PFN,*** the excellent intrinsic sensitivity of the thick PFTN film,a single sensing unit with integrated electrode design can imitate human skin for touch detection,pressure perception and traction *** sensing range of our multimodal tactile sensor reaches~150 Pa,and it exhibits a linear fit over 97%for both normal pressure and shear *** also demonstrate that an electronic skin,made of an array of sensing units,is capable of accurately recognizing complex tactile interactions including pinch,spread,and tweak motions.

关键词： sensation intrinsic modal