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Natural products inspired[3+2]cycloaddition enables efficient construction of hydroxylated tetrahydrofuran acetals and concise syntheses of lignans

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Science China Chemistry 2024年第7期67卷 2306-2313页

作者： dong-yue Cai Weiming Shi Zhao-Hui Jin Zhi-Xiang Yu Jin-Xin Zhao Jian-Min yue State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China Beijing National Laboratory for Molecular Sciences(BNLMS) Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of ChemistryPeking UniversityBeijing 100871China

Mimicking biosynthetic pathways of hongkonoids led to the development of a new Cu(Ⅰ)-catalyzed[3+2]cycloaddition ofα-hydroxyketone andβ-keto enol ethers,affording tetrahydrofuran acetals in a highly diastereoselective manner and 100%atom *** studies on the mechanism disclosed a concerted but asynchronous Michael addition/aldol *** the same importance,this methodology provides a practical biomimetic approach for one-step construction of the dibenzylbutyrolactol lignan backbone starting from two phenyl propane derivatives,opening up a powerful new approach for lignan synthesis,which is showcased by succinct total syntheses of two biologically important aryltetralin-type lignans,β-apopicropodophyllin and *** the mild and operationally simple conditions,the developed chemistry might have a promising prospect in potential industrial applications.

关键词： [3+2]cycloaddition transition-metal catalysis tetrahydrofuran lignans natural products

Regulating the oxidation state of Pd to enhance the selective hydrogenation for 5-hydroxymethylfurfural

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Chinese Journal of Chemical Engineering 2024年第8期72卷 60-68页

作者： Xin Li yue Ma Xuning Wang Jianguo Wu dong Cao Daojian Cheng State Key Laboratory of Organic-Inorganic Composites and College of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China

The highly selective hydrogenation of 5-hydroxymethylfurfural to 2,5-dihydroxymethylfuran is an important reaction in the field of biomass hydrogenation,because it is a bridge between biomass resources and chemical ***,we precisely constructed carbon nitride supported Pd-based catalysts by a simple impregnation-reduction *** changing the reduction temperature,catalysts with different oxidation state could be precisely ***,the important correlation between the ratio of Pd^(0)/Pd^(2+)and catalytic activity is revealed during the selective hydrogenation of *** Pd/g—C_(3)N_(4)—300 catalyst with a Pd^(0)/Pd^(2+)ratio of 3/2 showed the highest catalytic activity,which could get 96.9%5-hydroxymethylfurfural conversion and 90.3%2,5-dihydroxymethylfuran *** density functional theory calculation revealed that the synergistic effect between Pd0and Pd2+in Pd/g—C_(3)N_(4)—300 system could boost the adsorption of the substrate and the dissociation of *** this work,we highlight the important correlation between metal oxidation state and catalytic activity,which provides valuable insights for the rational design of precious metal catalysts for hydrogenation reactions.

关键词： Pd/g-C_(3)N_(4) Selective hydrogenation 5-hydroxymethylfurfural 2,5-dihydroxymethylfuran Oxidation state

Relative difficulty distillation for semantic segmentation

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Science China(Information Sciences) 2024年第09期67卷 126-145页

作者： dong LIANG yue SUN Yun DU Songcan CHEN Sheng-Jun HUANG MIIT Key Laboratory of Pattern Analysis and Machine Intelligence College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics Shenzhen Research Institute Nanjing University of Aeronautics and Astronautics

Current knowledge distillation(KD) methods primarily focus on transferring various structured knowledge and designing corresponding optimization goals to encourage the student network to imitate the output of the teacher network. However, introducing too many additional optimization objectives may lead to unstable training, such as gradient conflicts. Moreover, these methods ignored the guidelines of relative learning difficulty between the teacher and student networks. Inspired by human cognitive science, in this paper, we redefine knowledge from a new perspective — the student and teacher networks' relative difficulty of samples, and propose a pixel-level KD paradigm for semantic segmentation named relative difficulty distillation(RDD). We propose a two-stage RDD framework: teacher-full evaluated RDD(TFE-RDD) and teacher-student evaluated RDD(TSE-RDD). RDD allows the teacher network to provide effective guidance on learning focus without additional optimization goals, thus avoiding adjusting learning weights for multiple losses. Extensive experimental evaluations using a general distillation loss function on popular datasets such as Cityscapes, Cam Vid, Pascal VOC, and ADE20k demonstrate the effectiveness of RDD against state-ofthe-art KD methods. Additionally, our research showcases that RDD can integrate with existing KD methods to improve their upper performance bound. Codes are available at https://***/sunyueue/***.

关键词： knowledge distillation semantic segmentation relative difficulty sample weighting prediction discrepancy

Synthesis of NaY zeolite from a submolten depolymerized perlite:Alkalinity effect and crystallization kinetics

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Chinese Journal of Chemical Engineering 2024年第6期70卷 130-138页

作者： Yanli Qu Peng dong Li Yang Yuanyuan yue Haoliang Wang Jingcai Cheng Chao Yang CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Petroleum Molecular&Process EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100190China Qingyuan Innovation Laboratory Quanzhou 362801China National Engineering Research Center of Chemical Fertilizer Catalyst College of Chemical EngineeringFuzhou UniversityFuzhou 350108China

NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred *** of alkalinity ranging from 0.38 to 0.55(n(Na_(2)O)/n(SiO_(2)))on the relative crystallinity,textural properties and crystallization kinetics were *** results show that alkalinity exerts a nonmonotonic influence on the relative crystallinity and textural properties,which exhibit a maximum at the alkalinity of *** nucleation kinetics are studied by fitting the experimental data of relative crystallinity with the Gualtieri *** is shown that the nucleation rate constant increases with increasing alkalinity,while the duration period of nucleation decreases with increasing *** n(Na_(2)O)/n(SiO_(2))ratios ranging from 0.38 to 0.55,the as-synthesized NaY zeolites exhibit narrower crystal size distributions with the increase in *** growth rates determined from the variations of average crystal size with time are 51.09,157.50,46.17 and 24.75 nm·h^(-1),*** is found that the larger average crystal sizes at the alkalinity of 0.38 and 0.43 are attributed to the dominant role of crystal growth over ***,the combined action of prominent crystal growth and the longer duration periods of nucleation at the alkalinity of 0.38 and 0.43 results in broader crystal size *** findings demonstrate that control of the properties of NaY zeolite and the crystallization kinetics can be achieved by conducting the crystallization process in an appropriate range of alkalinity of the reaction mixture.

关键词： NaY zeolite Submolten salt depolymerized perlite Alkalinity Crystallization kinetics

Spatial Analysis of the Aging Population and Socio-economic Factors of China:Global and Local Perspectives

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Journal of Geodesy and Geoinformation Science 2024年第2期7卷 37-51页

作者： LU Binbin dong Zheyi yue Peng QIN Kun School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430072China

Population aging has become an inevitable trend and exerted profound influences on socio-economic development in *** this study,we utilized data from national population census and statistical yearbooks in 2010 and 2020 to explore spatio-temporal patterns of aging population and its coupling correlations with socio-economic factors from both global and local *** results from Local Indicators of Spatial Association(LISA)uncover notable spatial disparities in aging population rates,with higher rates concentrated in the eastern regions and lower rates in the western areas of the Chinese *** results from the global correlation analysis with the changes in aging population rates show significant positive correlations with government interventions and industrial structures,but negatively correlated with economic development,social consumption,and medical *** a local perspective,a Geographically Weighted(GW)correlation analysis is employed to uncover local correlations between aging trends and socio-economic *** insights gained from this technique not only underscore the complexity and diversity of economic implications stemming from population aging,but also provide invaluable guidance for crafting region-specific economic policies tailored to various stages of population aging.

关键词： spatial heterogeneity local technique GWmodelS GW correlation analysis,spatial autocorrelation

Lath-like phases formed at an extremely high temperature in a Mg-RE(RE=rare earth)-Al alloy

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Rare Metals 2024年第8期43卷 3937-3945页

作者： Bo Deng Shu-Hui Lv Qiang Yang dong-yue Zhao Jun-Yuan Fan Xin Qiu School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Chongqing Research Institute Changchun University of Science and TechnologyChongqing 401135China

Thermal stable intermetallic particles are important for the heat resistance of magnesium(Mg)*** this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at 873 ***-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM) characterizations indicate that most of them are Mg-containing Al_(2)(Gd,Sm),with the atomic ratio of Mg:Al:(Gd,Sm) being ~1:1:1;a small part of them with relatively wider thickness are long-period stacking ordered(LPSO) phases simultaneously containing both 14H and 18R *** followed common orientation relationships with Mg matrix as those reported in previous *** addition,many Mg laths were observed in the primary blocky Al_(2)(Gd,Sm) phase at grain boundaries,where the atomic ratio of Al:(Gd,Sm) in the Al_(2)(Gd,Sm) matrix was 2:***,density functional theory(DFT) calculations illustrated the detail structure of the re-constructed Mg/Al_(2)RE interface and simultaneously deduced the underlying reason for the re-dissolution of the newly formed Mg-containing Al_(2)(Gd,Sm) plates in α-Mg matrix.

关键词： Magnesium alloy HAADF-STEM Microstructures Intermetallic particles Orientation relationships Interfaces

A coating strategy on titanium implants with enhanced photodynamic therapy and CO-based gas therapy for bacterial killing and inflammation regulation

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Chinese Chemical Letters 2024年第2期35卷 386-395页

作者： Liang Cheng Bingshuai Zhou Manlin Qi Xiaolin Sun Shujun dong yue Sun Biao dong Lin Wang Yingwei Yang Department of Oral Implantology Jilin Provincial Key Laboratory of Sciences and Technology for Stomatology Nanoengineering School and Hospital of StomatologyJilin UniversityChangchun 130021China State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130021China College of Chemistry Jilin UniversityChangchun 130012China

Antimicrobial photodynamic therapy(aPDT)has been considered a noninvasive and effective modality against the bacterial infection of peri‑implantitis,especially the aPDT triggered by near-infrared(NIR)light due to the large penetration depth in ***,the complexity of hypoxia microenvironments and the distance of aPDT sterilization still pose challenges before realizing the aPDT clinical *** to the long lifespan and transmission distance of therapeutic gas molecules,we design a multi-functional gas generator that combines aPDT as well as O_(2) and CO gas release function,which can solve the problem of hypoxia(O_(2))in PDT and the problem of inflammation regulation(CO)in the distal part of peri‑implant inflammation under near-infrared(NIR)*** the composite nanoplatform that spin-coated on the surface of titanium implants,up-conversion nanoparticles(UCNPs)were involved in converting the NIR to visible,which further excites the partially oxidized stannic sulfide(SnS_(2)),realizing the therapeutic gas *** green(ICG)was further integrated to enhance the aPDT performance(Ti-U@SnS_(2)/I).Therefore,reactive oxygen species(ROS),CO,and O_(2) can be controllably administered via a composite nano-platform mediated by a single NIR light(808 nm).This implant surface modification strategy could achieve great self-enhancement antibacterial effectiveness and regulate the lingering questions,such as relieving the anoxic microenvironment and reaching deep infection sites,providing a viable antibiotic-free technique to combat peri‑implantitis.

关键词： Photodynamic therapy Biomaterials Dental implant Reactive oxygen species Carbon monoxide Hybrid nanoplatform

Microseismic source location using deep learning:A coal mine case study in China

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3407-3418页

作者： yue Song Enyuan Wang Hengze Yang Chengfei Liu Baolin Li dong Chen School of Safety Engineering China University of Mining and TechnologyXuzhou221116China State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou221116China School of Environment and Safety Engineering North University of ChinaTaiyuan030051China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining TechnologyXuzhou221116China

Microseismic source location is crucial for the early warning of rockburst ***,the conventional methods face challenges in terms of the microseismic wave velocity and arrival time *** techniques,such as the full convolutional neural network(FCNN),can capture spatial information but struggle with complex microseismic *** the FCNN with the long shortterm memory(LSTM)network enables better time-series signal classification by integrating multiscale information and is therefore suitable for waveform *** LSTM-FCNN model does not require extensive data preprocessing and it simplifies the microseismic source location through feature *** this study,we utilized the LSTM-FCNN as a regression learning model to locate the seismic ***,the method of short-time-average/long-time-average(STA/LTA)arrival time picking was employed to augment spatiotemporal ***,oversampling the on-site data was performed to address the issue of data imbalance,and finally,the performance of LSTM-FCNN was ***,we compared the LSTM-FCNN model with previous deep-learning *** results demonstrated remarkable location capabilities with a mean absolute error(MAE)of only 7.16 *** model can realize swift training and high accuracy,thereby significantly improving risk warning of rockbursts.

关键词： Microseismic source location Rockburst Deep learning Intelligent early warning

OSDA-free synthesis of FeZSM-22 zeolite from natural minerals for n-octane hydroisomerization

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Chinese Journal of Chemical Engineering 2024年第2期66卷 51-59页

作者： Tiesen Li Ting Chen Yinghui Ye Peng dong TinghaiWang Qingyan Cui Chan Wang Yuanyuan yue National Engineering Research Center of Chemical Fertilizer Catalyst College of Chemical EngineeringFuzhou UniversityFuzhou 350002China Qingyuan Innovation Laboratory Quanzhou 362801China

A seed-directed approach to synthesizing Fe ZSM-22 zeolite without organic structure directing agent(OSDA)was developed by using Fe-rich diatomite as all aluminum and iron *** Fe ZSM-22zeolite with optimal crystallinity and purity can be obtained by systematically adjusting feed composition and synthesis *** show that Fe ZSM-22 zeolite synthesized with OSDA-free owns high crystallinity,obvious thin needle-shaped morphology and high Bronsted/Lewis acid ***,when used for n-octane hydroisomerization reaction,its derived catalyst exhibits the best catalytic performance reflected by the highest selectivity to C_(8)isomers compared to the two reference catalysts prepared based on a Fe-containing and a Fe-free ZSM-22 synthesized through an OSDA-directed route from natural diatomite and conventional chemicals,*** work provides an alternative route to sustainably synthesizing heteroatomic zeolites with high performance.

关键词： FeZSM-22 zeolite OSDA-free synthesis Natural minerals n-octane hydroisomerization