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Engineering Ru（N^N）3-modified covalent organic framework for photocatalytic olefin epoxidation

Science China Chemistry 2024年第11期67卷 3719-3728页

作者： yan-Lin Li sheng-Li huang Guo-Yu yang Key Laboratory of Cluster Science (Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsSchool of Chemistry and Chemical Engineering Beijing Institute of Technology

Photocatalytic olefin oxidation using air as an oxidant is an environmentally friendly method for producing epoxides. Covalent organic frameworks（COFs） have emerged as promising photocatalysts in various organic synthesis reactions. The combination of tri-（2-pyridinal aldehyde）-containing precursor with 4,4’,4’’-（1,3,5-triazine-2,4,6-triyl）trianiline generated（N^N）-I-COF. Via imine-to-quinoline transformation and coordination anchorage of Ru（N^N）3unit, Ru（N^N）3@Q-COF was obtained with improved chemical stability, skeleton conjugation, and novel photochemical characteristics, and demonstrated excellent photocatalytic activity in olefin epoxidation with a wide range of substrates. The presence of H2O played a crucial role in the formation of reactive oxygen species（ROSs）, which in turn influenced the olefin oxidation process. The hydrophilicity of Ru（N^N）3facilitated the approach of H2O and O2to the photogenerated charges, thereby promoting ROSs generation. The lipophilicity of Q-COF allowed for the absorption of olefin substrates, and its nano-channels increased encountering possibility between olefins and ROSs. Consequently, Ru（N^N）3@Q-COF provided an intriguing platform for olefin photooxidation and could be recycled multiple times without any degradation in performance. This report revealed that the conversion of classical ROSs into less potent oxidants with rapid kinetic rates played a crucial role in achieving highly efficient and selective epoxidation of terminal olefins.

关键词： polypyridyl Ru covalent organic framework olefin epoxidation photocatalysis

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Achieving Synergistic Improvement in Dielectric and Energy Storage Properties of All-Organic Poly(Methyl Methacrylate)-Based Copolymers Via Establishing Charge Traps

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Energy & Environmental Materials 2024年第2期7卷 308-319页

作者： Guanghu He huang Luo Chuanfang yan Yuting Wan Dang Wu Hang Luo Yuan Liu sheng Chen Key Laboratory of Polymeric Materials and Application Technology of Hunan Province College of ChemistryXiangtan UniversityXiangtan 411105China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Guangdong University of Petrochemical Technology Maoming 525000China

How to achieve synergistic improvement of permittivity(ε_(r))and breakdown strength(E_(b))is a huge challenge for polymer ***,for the first time,theπ-conjugated comonomer(MHT)can simultaneously promote theε_(r)and E_(b)of linear poly(methyl methacrylate)(PMMA)*** PMMA-based random copolymer films(P(MMA-co-MHT)),block copolymer films(PMMA-b-PMHT),and PMMA-based blend films were prepared to investigate the effects of sequential structure,phase separation structure,and modification method on dielectric and energy storage properties of PMMA-based dielectric *** a result,the random copolymer P(MMA-coMHT)can achieve a maximumε_(r)of 5.8 at 1 kHz owing to the enhanced orientation polarization and electron *** electron injection and charge transfer are limited by the strong electrostatic attraction ofπ-conjugated benzophenanthrene group analyzed by the density functional theory(DFT),the discharge energy density value of P(MMA-co-PMHT)containing 1 mol%MHT units with the efficiency of 80%reaches15.00 J cm^(-3)at 872 MV m^(-1),which is 165%higher than that of pure *** study provides a simple and effective way to fabricate the high performance of polymer dielectrics via copolymerization with the monomer of P-type semi-conductive polymer.

关键词： dielectric capacitor electrical properties energy density polymer dielectric semiconductor polymer

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The Multiple Roles of Autophagy in Neural Function and Diseases

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Neuroscience Bulletin 2024年第3期40卷 363-382页

作者： yan-yan Li Zheng-Hong Qin Rui sheng Department of Pharmacology and Laboratory of Aging and Nervous Diseases Jiangsu Key laboratory of Neuropsychiatric DiseasesCollege of Pharmaceutical Sciences of Soochow UniversitySuzhou 215123China

Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes,where proteins,lipids,and organelles are degraded and *** to the way the cytoplasmic components are engulfed,autophagy can be divided into macroautophagy,microautophagy,and chaperone-mediated ***,many studies have found that autophagy plays an important role in neurological diseases,including Alzheimer's disease,Parkinson's disease,Huntington's disease,neuronal excitotoxicity,and cerebral *** maintains cell homeostasis in the nervous system via degradation of misfolded proteins,elimination of damaged organelles,and regulation of apoptosis and ***-mTOR,Beclin 1,TP53,endoplasmic reticulum stress,and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological ***,we discuss the role,functions,and signal pathways of autophagy in neurological diseases,which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.

关键词： Autophagy Neurodegenerative diseases Cerebral ischemia AMPK mTOR Beclin 1 TP53 Endoplasmic reticulum stress

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Evaluation and application of kinetic models for Cu-catalyzed acetylene hydrochlorination

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Chinese Journal of Chemical Engineering 2024年第8期72卷 209-219页

作者： Tianxiao huang Binhang yan Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

The development of environmentally friendly catalysts has become a top priority for acetylene ***,difficulties remain in systematic studies on the applicability of kinetic models for the industrialization of Cu-based ***,a strategy involving reactor modeling,parameter estimation,and model testing is developed to evaluate the predictive ability of kinetic *** order to search for reliable and widely applicable reaction kinetic models for Cu-based catalysts,a case study is *** possible kinetic models derived from the power law,adsorption mechanism,and reaction path are sifted through collecting and testing activity data from tens of Cu-based *** optimum applicable ranges of these kinetic models are *** to the comparative analysis on their applications in various industrial scenarios,this research suggests that kinetic models derived from reaction path exhibits the best extrapolation ability and has the greatest potential for application in the scale-up design of reactors.

关键词： Acetylene hydrochlorination Cu-based catalysts Reaction kinetics Model Reactors

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A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

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Journal of Materials Science & Technology 2024年第5期172卷 202-212页

作者： Fei huang Jiyong Hu Xiong yan Shanghai Frontier Science Research Center for Modern Textiles Donghua UniversityShanghai 201620China

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide ***,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body ***,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain *** proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite *** strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the ***,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural *** final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,*** sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

关键词： Double-threaded yarn Strain redistribution Hysteresis Human motion monitoring

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Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： Jian-sheng HAO yan WANG Lan-Hai LI Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of Xinjiang Xinyuan 835800China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(p<0.01)during the snow season,along with more extreme snowfall *** snow-cover duration was observed to have been shortened by 4.77 d per decade(p<0.01)from 1967 to 2021,which is characterised by later snow-cover onset and earlier ***,average and maximum snow depths increased along with an increase in peak snow water equivalent,thus indicating a higher frequency of extremely scarce or abundant snow *** low snowpack temperature gradient and earlier snowmelt dates in spring lead to earlier occurrences of snowmelt floods and wet *** the risks of these events increase,they pose greater threats to farmlands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

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A Deep Model for Partial Multi-label Image Classification with Curriculum-based Disambiguation

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Machine Intelligence Research 2024年第4期21卷 801-814页

作者： Feng Sun Ming-Kun Xie sheng-Jun huang MIIT Key Laboratory of Pattern Analysis and Machine Intelligence College of Computer Science and TechnologyNanjing University of AeronauticsandAstronauticsNanjing211106China

In this paper,we study the partial multi-label(PML)image classification problem,where each image is annotated with a candidate label set consisting of multiple relevant labels and other noisy *** PML methods typically design a disambiguation strategy to filter out noisy labels by utilizing prior knowledge with extra assumptions,which unfortunately is unavailable in many real ***,because the objective function for disambiguation is usually elaborately designed on the whole training set,it can hardly be optimized in a deep model with stochastic gradient descent(SGD)on *** this paper,for the first time,we propose a deep model for PML to enhance the representation and discrimination *** the one hand,we propose a novel curriculum-based disambiguation strategy to progressively identify ground-truth labels by incorporating the varied difficulties of different *** the other hand,consistency regularization is introduced for model training to balance fitting identified easy labels and exploiting potential relevant *** experimental results on the commonly used benchmark datasets show that the proposed method significantlyoutperforms the SOTA methods.

关键词： Partial multi-label image classification curriculum-based disambiguation consistency regularization label difficulty candidatelabel set.

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Flexible MXene/sodium alginate composite fabric with high structural stability and oxidation resistance for electromagnetic interference shielding

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Nano Research 2024年第6期17卷 5326-5335页

作者： Hao-Wen Zhang Lu-Yao yang Meng-Lin huang Ming-Hua Cheng Zhe-sheng Feng Fanbin Meng Zifeng Lin yan Wang School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China College of Materials Science and Engineering Sichuan UniversityChengdu 610065China

Wearable electromagnetic interference(EMI)shielding fabrics with excellent electromagnetic shielding performance,oxidation resistance,and structural stability are highly demanded for the rapid development of electronic devices and wireless *** are metallic conductive materials with exceptional EMI shielding properties,but they are prone to oxidation in air and have poor structural stability and durability on fabric ***,we present a one-step assembly method to fabricate fabrics coated with MXenes and polymeric sodium alginate(SA)composite(MXene-SA).SA protects MXenes from oxidation and forms a stable interlayer structure by bonding to *** MXene-SA coated fabrics are breathable and flexible,and have a low sheet resistance of 2.12±0.08Ω/sq and a high EMI shielding performance of 37.05 dB at X-band,which is comparable to the best 42.31 ***,the MXene-SA coated fabrics exhibit high structural stability and oxidation resistance under various conditions of sonication disintegration,mechanical abuse,chemical corrosion,and humidity,compared to pure MXenes coated *** believe that the wearable and high-performance MXene-SA fabrics have great potential for the next generation of ultra-portable and wearable EMI shielding products.

关键词： MXenes electromagnetic interference shielding fabric one-step assembly

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Cholic acid mitigates osteoarthritis by inhibiting the NF-κB/PERK/ SIRT1 signaling pathway

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BIOCELL 2024年第7期48卷 1095-1104页

作者： JIAOE sheng ZUMIN YI SANSHAN HE QINGCHAO WU XIA huang GUOQING yan YUFANG DAI LINCHONG SU The Minda Hospital of Hubei Minzu University Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic DiseaseEnshi445000China The Obstetrics and Gynecology of Jianshi County Hospital of Traditional Chinese Medicine Enshi445300China

Introduction:Cholic acid(CA)is a natural steroid useful in treating chronic bronchitis and *** the other hand,its potential impact on osteoarthritis(OA)is ***:Using an in vitro and in vivo osteoarthritis model,we sought to assess the chondroprotective properties of ***:We employed the Cell Counting Kit-8 to measure the impact of CA on chondrocyte activity to assess the toxicity of the *** molecular biology experimental techniques were used to investigate potential signaling pathways that CA may use to prevent inﬂammation and give chondrocytes ***,how CA affects the OA model in Sprague-Dawley(SD)rats was ***:CA signiﬁcantly suppressed the up-regulation of the interleukin-1β(IL-1β),cyclooxygenase-2(COX-2),and matrix metalloproteinase 13(MMP-13)and the downregulation of aggrecan and type II collagen A1(COL2A)in chondrocytes treated tumor necrosis factor-alpha(TNF-α).Differentially expressed genes(DEG)enrichment revealed IL-17,TNF,chemokine,cytokine-cytokine receptor,toll-like receptor,and nucleotide oligomerization domain-like receptor were the primary signaling *** enriched DEGs included CXCL6,CCL20,MMP3,CXCL3,CXCL11,CCL5,CXCL10,MMP9,MMP13,and CXCL2;these DEGs are involved in inﬂammatory responses and their expression induced by TNF-αwas reversed by CA *** inhibits p65 nuclear translocation and inhibitory subunit kappa B alpha(IκBα)phosphorylation induced by TNF-α.Furthermore,CA attenuated protein expression of protein kinase RNA-like endoplasmic reticulum kinase(PERK),inositol-requiring transmembrane kinase/endoribonuclease 1α(IRE1α),glucose regulatory protein 78(GRP78),and sirtuin 1(SIRT1),and down-regulation of phosphorylation of AMP-activated protein kinase-α(p-AMPKα)in TNF-α-treated ***:CA signiﬁcantly ameliorated cartilage degradation in the OA rat *** alleviated the inﬂammatory response through the nuclear factor kappa B/PERK/SIRT1 axis and

关键词： Cholic acid Cartilage Inﬂammation RNA sequencing Differentially expressed genes

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Radical involved reactive wetting and retarding mechanism of alumina refractory ceramic by molten slags under weak static magnetic field

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Journal of Iron and Steel Research International 2024年第6期31卷 1355-1366页

作者： sheng-hao Li Ao huang Fan-bo Zeng Hui Peng Hao-ran Wei Xue-chun huang sheng-qiang Song Hua-zhi Gu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

High alumina slag will cause severe corrosion at the interface of alumina refractory,and the wetting behavior of slag is a key factor influencing the corrosion resistance of refractory *** static magnetic field is a promising solution for improvement in the slag resistance of *** wetting of alumina refractory ceramics with different basicities of high alumina slags under a weak static magnetic field was analyzed,given that a weak static magnetic field can affect the corrosion behavior of refractory *** slag S_(3) as an example,when there was an external static magnetic field of 1.0 mT at 1600 ℃,the thickness of calcium aluminate reaction layer at the interface decreased by 36.7%,the denting depth of interface decreased by 35.6%,and the apparent wetting angle increased by 20%.The living radicals and their formation path in oxide melts were verified by first-principles calculation combined with electron paramagnetic resonance spectroscopy *** influence of the flux density of a weak static magnetic field on the wetting behavior of slags was also *** contact angle of the slags increased owing to the inhibitory effect of magnetic field on the radicalinvolved reaction at the interface of the slag and the alumina refractory *** relationships between the magnetic flux density,diffusion coefficient,slag microstructure(hyperfine coupling constant),and contact angle were *** provides a theoretical basis for the field control of radical involved reactive wetting between inorganic oxide slags and solid oxide ceramics.

关键词： Alumina refractory ceramic Molten slag Weak magnetic field effect Reactive wetting Free radical

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