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Enhanced photothermal dehydration of methanol over W_(18)O_(49)/Au/SAPO-34 catalysts with broadened light absorption

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Rare Metals 2024年第3期43卷 1139-1152页

作者： Ya-Qin Tang Meng-Xia Yan Chang-Qian Lu Shao-Yuan Li Kui-Xian Wei Tao Qu Wen-HuiMa Yong-Nian Dai Kong-Zhai Li Da-Jun Luo Xue-Liang Zhang Yi-Ke Liu faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming650093China School of Materials and Energy Engineering Guizhou Institute of TechnologyGuiyang550003China

Methanol-to-olefins(MTO)process is one of the most critical pathways to produce low carbon ***,the reaction is driven by thermal catalysis,which inevitably needs to consume large amounts of fossil *** a new technique to substitute for the fuel burning is urgent for MTO process to improve the industry prospects and ***,we report a novel W_(18)O_(49)/Au/SAPO-34(W/Au/S),a multifunctional photothermal catalyst for the MTO reaction.A high methanol conversion was achieved under xenonum(Xe)lamp irradiation,yielding methyl ether(ME)and ethylene as the main *** optimized W/Au/S catalysts showed ethylene yield as high as 250μmol in 60 min,which was 2.5 times higher than that of Au/*** physiochemical characterization revealed that the SAPO-34 molecular sieves were surrounded by Au and W_(18)O_(49)nanoparticles,which exhibited a strong localized surface plasmon resonance excitation around 540 nm and light absorption beyond 500 *** multifunctional catalysts showed a strong photothermal effect,arising from the broadened light absorption of Au and W_(18)O_(49)nanoparticles,leading to a temperature as high as 250℃on the surface of the *** study showed that the superior ethylene selectivity of W/Au/S catalysts was attributed to the moderating acidic sites of W_(18)O_(49)for methanol dehydration to *** research may provide new insight for designing heterostructures to improve photo-to-chemical conversion performance and is expected to accelerate progress toward the excellent multifunctional photothermal catalysts with broad light absorption for methanol activation and C-C bond formation.

关键词： Methanol conversion Ethylene Photothermal catalysis W_(18)O_(49) BrΦnsted-acid

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Advanced rare earth tantalate RETaO_(4)(RE=Dy,Gd and Sm) with excellent oxygen/thermal barrier performance

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Journal of Rare Earths 2024年第8期42卷 1595-1603,I0007页

作者： Jun Wang Jianyu Li Chunyu Jiang Jianbo Song Xing Yang Xiaolong Ma Kailiang Luo Peng Wu Xiaoyu Chong Jing Feng faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming650093China Shanxi Tianxuan Coating technology Co. LtdXi'an710000China

Thermal barrier coatings(TBCs) materials with lowered the rmal and oxygen ion conductivity can provide thermal and oxidative protection for high te mperature hot-end components in aero nautical engines and gas turbines,The rare-earth tantalate RETaO_(4)(RE=Dy,Gd and Sm) ceramics with monoclinic(m) phase were successfully synthesized via spark plasma *** vacancies responsible for the thermal and oxygen ion conductivities of RETaO_(4) were demonstrated by atomic-resolution energy dispersive Xray and X-ray photoelectron *** the three samples,DyTaO_(4) has excellent oxygen/thermal barrier *** to the current service thermal barrier coating material ZrO_(2)-8 wt% Y_(2)O_(3)(8 YSZ),DyTaO_(4) has an ultra-low oxygen ion conductivity benefiting from low oxygen vacancy concentration and strong stretching force *** intrinsic thermal conductivity of DyTaO_(4)is 68.2% less than that of 8 ***,the thermal expansion rate curves indicate that the phase transformation does not happen from room te mperature to 1200℃.The above results demonstrate that high-growth rate the rmally grown oxide can be retarded by creating dense DyTaO_(4) coating with lowered thermal and oxygen ion conductivity.

关键词： Thermal barrier coatings Rare earths Oxygen vacancies Thermal conductivity Oxygen ion conductivity

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Phosphine-Catalyzed [4+3] Annulation Reaction of Indole Derivatives with MBH Carbonates:A Facile Access to Indole-1,2-fused 1,4-Diazepinones and Azepines

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Chinese Journal of Chemistry 2024年第3期42卷 271-275页

作者： Yannan Zhu Haoran Jiang Yi-Ning Wang faculty of Chemistry and Chemical Engineering Yancheng Institute of TechnologyYanchengJiangsu224051 China

A phosphine-catalyzed [4+3] annulation between dinucleophilic indole derivatives and Morita−Baylis−Hillman (MBH) carbonates was discovered by using the N1 and N4′/C4′ nucleophilicities of the indole precursors,in which indoles act as four atom synthons. This protocol provides an efficient and facile access to indole-1,2-fused 1,4-diazepinones and azepines in good to high yields in one step,which illustrates potential synthetic utilities in drug discovery.

关键词： Phosphine catalysis [4+3]Annulation Indole derivatives Nitrogen heterocycles Organocatalysis

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Zonal activation of molecular carbon dioxide and hydrogen over dual sites Ni-Co-MgO catalyst for CO_(2) methanation:Synergistic catalysis of Ni and Co species

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Journal of Energy Chemistry 2024年第4期91卷 213-225页

作者： Zonglin Li Jianjun Chen Yu Xie Junjie Wen Huiling Weng Mingxue Wang Jingyi Zhang Jinyan Cao Guocai Tian Qiulin Zhang Ping Ning faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500YunnanChina National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries Kunming University of Science and TechnologyKunming 650500YunnanChina faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina

An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed ***,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation *** abundant surface nickel and cobalt components as active sites led to strong Ni-Co interaction with charge transfer from nickel to ***,electron-enriched Coδ-species participated in efficient chemisorption and activation of CO_(2)to generate monodentate ***,plentiful available Ni0sites facilitated H2dissociation,thus CO_(2)and H2were smoothly activated at zones of Coδ-species and Ni0,*** in situ DRIFTS,quasi situ XPS,TPSR,and DFT calculations substantiated a new formate evolution mechanism via monodentate carbonate instead of traditional bidentate carbonate based on synergistic catalysis of Coδ-species and *** zonal activation of CO_(2)and H2by tuning electron behaviors of double-center catalysts can boost heterogeneous catalytic hydrogenation performance.

关键词： Zonal activation CO_(2) methanation Dual active sites Synergistic effect

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Adaptive Optimal Discrete-Time Output-Feedback Using an Internal Model Principle and Adaptive Dynamic Programming

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 131-140页

作者： Zhongyang Wang Youqing Wang Zdzisław Kowalczuk the College of Information Science and technology Beijing University of Chemical TechnologyBeijing 100029China IEEE the Department of Robotics and Decision Systems Faculty of ElectronicsTelecommunications and InformaticsGdańsk University of TechnologyGdansk 80-233Poland

In order to address the output feedback issue for linear discrete-time systems, this work suggests a brand-new adaptive dynamic programming(ADP) technique based on the internal model principle(IMP). The proposed method, termed as IMP-ADP, does not require complete state feedback-merely the measurement of input and output data. More specifically, based on the IMP, the output control problem can first be converted into a stabilization problem. We then design an observer to reproduce the full state of the system by measuring the inputs and outputs. Moreover, this technique includes both a policy iteration algorithm and a value iteration algorithm to determine the optimal feedback gain without using a dynamic system model. It is important that with this concept one does not need to solve the regulator equation. Finally, this control method was tested on an inverter system of grid-connected LCLs to demonstrate that the proposed method provides the desired performance in terms of both tracking and disturbance rejection.

关键词： Adaptive dynamic programming(ADP) internal model principle(IMP) output feedback problem policy iteration(PI) value iteration(VI)

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Intelligent Machine Learning Based Brain Tumor Segmentation through Multi-Layer Hybrid U-Net with CNN Feature Integration

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Computers, Materials & Continua 2024年第4期79卷 1301-1317页

作者： Sharaf J.Malebary Department of Information technology Faculty of Computing and Information TechnologyKing Abdulaziz UniversityP.O.Box 344Rabigh21911Saudia Arabia

Brain tumors are a pressing public health concern, characterized by their high mortality and morbidity ***, the manual segmentation of brain tumors remains a laborious and error-prone task, necessitatingthe development of more precise and efficient methodologies. To address this formidable challenge, we proposean advanced approach for segmenting brain tumorMagnetic Resonance Imaging (MRI) images that harnesses theformidable capabilities of deep learning and convolutional neural networks (CNNs). While CNN-based methodshave displayed promise in the realm of brain tumor segmentation, the intricate nature of these tumors, markedby irregular shapes, varying sizes, uneven distribution, and limited available data, poses substantial obstacles toachieving accurate semantic segmentation. In our study, we introduce a pioneering Hybrid U-Net framework thatseamlessly integrates the U-Net and CNN architectures to surmount these challenges. Our proposed approachencompasses preprocessing steps that enhance image visualization, a customized layered U-Net model tailoredfor precise segmentation, and the inclusion of dropout layers to mitigate overfitting during the training ***, we leverage the CNN mechanism to exploit contextual information within brain tumorMRI images,resulting in a substantial enhancement in segmentation *** experimental results attest to the exceptionalperformance of our framework, with accuracy rates surpassing 97% across diverse datasets, showcasing therobustness and effectiveness of our approach. Furthermore, we conduct a comprehensive assessment of ourmethod’s capabilities by evaluating various performance measures, including the sensitivity, Jaccard-index, andspecificity. Our proposed model achieved 99% accuracy. The implications of our findings are profound. Theproposed Hybrid U-Net model emerges as a highly promising diagnostic tool, poised to revolutionize brain tumorimage segmentation for radiologists and clinician

关键词： Brain tumor Hybrid U-Net CLAHE transfer learning MRI images

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Characterization and Selection of Microcrystalline Cellulose from Oil Palm Empty Fruit Bunches for Strengthening Hydrogel Films

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Journal of Renewable Materials 2024年第3期12卷 513-537页

作者： Susi Susi Makhmudun Ainuri Wagiman Wagiman Mohammad Affan Fajar Falah Department of Agroindustrial technology Faculty of AgricultureUniversitas Lambung MangkuratJl A Yani Km 36BanjarbaruSouth Kalimantan70714Indonesia Doctoral Programme of Agroindustrial technology Faculty of Agricultural TechnologyUniversitas Gadjah MadaJl Flora No.1BulaksumurYogyakarta55281Indonesia Department of Agroindustrial technology Faculty of Agricultural TechnologyUniversitas Gadjah MadaJl Flora No.1BulaksumurYogyakarta55281Indonesia

Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high *** implemented in other polymers,high crystallinity correlates with greater strength and stiffnes,but it can reduce the water-holding *** acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity,both of which have significance as properties of hydrogel *** study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid(HCl)and the appropriate hydrolysis time as a filler for film *** was produced by hydrolyzing cellulose of oil palm empty fruit bunches(OPEFB)with the HCl solution at varied concentrations and *** results show that the longer hydrolysis times and higher HCl concentrations increase crystallinity and density while lowering yield and water *** extensive acid hydrolysis reduces the amorphous area significantly,allowing the depolymerization to occur and extend the crystalline *** morphological properties of the MCC,which are smaller but compact,indicate the presence of disintegrating and diminishing structures.A 2.5 N HCl concentration and a 45-min hydrolysis time succeed in sufficient crystallinity as well as maintaining good water absorption *** treatment produced MCC with absorption capacity of 4.03±0.26 g/g,swelling capacity of 5.03±0.26 g/g,loss on drying of 1.44%±0.36,bulk and tapped density of 0.27±0.031 g/cm^(3) and 0.3±0.006 g/cm^(3),respectively,with a crystallinity index of 88.89%±4.76 and a crystallite size of 4.23±0.70 *** MCC generated could potentially be utilized as a hydrogel film filler,since a given proportion will be able to maintain the strength of the hydrogel,not readily dissolve but absorb water significantly.

关键词： Acid hydrolysis hydrogel OPEFB microcrystalline cellulose water absorption

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Semantic-aware entity alignment for low resource language knowledge graph

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Frontiers of Computer Science 2024年第4期18卷 97-106页

作者： Junfei TANG Ran SONG Yuxin HUANG Shengxiang GAO Zhengtao YU faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Yunnan Key Laboratory of Artificial Intelligence Kunming University of Science and TechnologyKunming 650500China

Entity alignment(EA)is an important technique aiming to find the same real entity between two different source knowledge graphs(KGs).Current methods typically learn the embedding of entities for EA from the structure of KGs for *** EA models are designed for rich-resource languages,requiring sufficient resources such as a parallel corpus and pre-trained language ***,low-resource language KGs have received less attention,and current models demonstrate poor performance on those low-resource ***,researchers have fused relation information and attributes for entity representations to enhance the entity alignment performance,but the relation semantics are often *** address these issues,we propose a novel Semantic-aware Graph Neural Network(SGNN)for entity ***,we generate pseudo sentences according to the relation triples and produce representations using pre-trained ***,our approach explores semantic information from the connected relations by a graph neural *** model captures expanded feature information from *** results using three low-resource languages demonstrate that our proposed SGNN approach out performs better than state-of-the-art alignment methods on three proposed datasets and three public datasets.

关键词： graph neural network knowledge graph entity alignment low-resource language

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Enhancing low-resource cross-lingual summarization from noisy data with fine-grained reinforcement learning

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Frontiers of Information technology & Electronic Engineering 2024年第1期25卷 121-134页

作者： Yuxin HUANG Huailing GU Zhengtao YU Yumeng GAO Tong PAN Jialong XU faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650504China Yunnan Key Laboratory of Artificial Intelligence Kunming University of Science and TechnologyKunming 650504China

Cross-lingual summarization(CLS)is the task of generating a summary in a target language from a document in a source ***,end-to-end CLS models have achieved impressive results using large-scale,high-quality datasets typically constructed by translating monolingual summary corpora into CLS ***,due to the limited performance of low-resource language translation models,translation noise can seriously degrade the performance of these *** this paper,we propose a fine-grained reinforcement learning approach to address low-resource CLS based on noisy *** introduce the source language summary as a gold signal to alleviate the impact of the translated noisy target ***,we design a reinforcement reward by calculating the word correlation and word missing degree between the source language summary and the generated target language summary,and combine it with cross-entropy loss to optimize the CLS *** validate the performance of our proposed model,we construct Chinese-Vietnamese and Vietnamese-Chinese CLS *** results show that our proposed model outperforms the baselines in terms of both the ROUGE score and BERTScore.

关键词： Cross-lingual summarization Low-resource language Noisy data Fine-grained reinforcement learning Word correlation Word missing degree

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Synergistic Effects of Carbon Nanotube(CNT)and Reduced Graphene Oxide(RGO)on Mechanical and Thermal Properties of ZK61 Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 577-585页

作者： Fanjing Meng Wenbo Du Ning Ding Jian Sun Xian Du Ke Liu Shubo Li College of Materials Science and Engineering Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

The hybrid of carbon nanotube(CNT)and reduced graphene oxide(RGO)reinforced ZK61 composite was fabricated by a hot extrusion *** with the raw ZK61 alloy and single-reinforced composites,the hybrid-reinforced by RGO+CNT complex exhibited significant enhancements both in mechanical and thermal *** adjusting the proportion of RGO and CNT in ZK61 alloy,the obtained optimum ZK61/(0.06 wt%RGO+0.54 wt%CNT)composite exhibited increase of 25.4%in yield strength,26.5%in ultimate tensile strength,104%in failure strain and 30.4%in thermal conductivity,respectively,in comparison with ZK61 *** superior properties of the nano-hybrid composite are attributed to the synergetic effects of RGO and CNT,leading to a uniform dispersion and integrated structure as well as the enhanced interfacial bonding with *** strengthening ability of RGO and CNT was calculated to quantify their individual contribution to the improvement in mechanical and thermal properties of the ZK61 matrix *** RGO+CNT hybrids provide a promising way to develop Mg matrix composites with impressive performances.

关键词： Mg matrix composite Carbon nanotube Reduced graphene oxide Mechanical performance Thermal conductivity

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