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Copper-catalyzed one-pot reactions of acetyl chloride, o-halobenzoic acids and Wittig reagents toward 3-methyl isocoumarin synthesis

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RSC ADVANCES 2017年第60期7卷 37839-37843页

作者： chen, xuwen Liu, Yunyun Jiangxi Normal Univ Coll Chem & Chem Engn Nanchang 330022 Jiangxi Peoples R China

The one-pot reactions of acetyl chloride, o-halobenzoic acids and Wittig reagents providing 3-methyl isocoumarins have been furnished via tandem Wittig reaction, oxa-Michael addition and C-C cross coupling. Three new chemical bonds including one C-O, one C=C and one C-C bond are generated via the catalysis of a simple copper salt for the heterocycle construction.

关键词： Catalysis

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Research on the three-dimensional visual management and control for marine intelligent mould bed based on digital twin

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SHIPS AND OFFSHORE STRUCTURES 2024年第6期19卷 756-768页

作者： Zhou, Honggen Yan, Zhanghui Jing, xuwen chen, Yu Liu, Jinfeng Zou, Xiaofeng Kang, Chao Li, Bingqiang Xie, Yang Yan, Dejun Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang Peoples R China CSSC Huangpu Wenchong Shipbuilding Co Ltd Guangdong Prov Key Lab Adv Welding Technol Ships Guangzhou Peoples R China Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212100 Jiangsu Peoples R China

Mould bed is crucial for supporting the ship subsection and controlling its deformation during shipbuilding. However, its visualisation and control process intelligence are often inadequate, leading to reduced accuracy and efficiency in ship subsection construction. Aiming at the problem, a three-dimensional (3D) visual monitoring method for the marine intelligent mould bed is proposed based on digital twin, and the overall framework of the management and control system is designed. Meanwhile, a fuzzy PID control principle optimised by the genetic algorithm is proposed to better control the deformation of the ship subsection. On this basis, the verification of the developed system is carried out based on the physical intelligent mould bed, and the 3D visual management and control of the marine intelligent mould bed are realised. It provides a foundation for improving the accuracy and efficiency of ship subsection construction.

关键词： Digital twin intelligent mould bed management and control system visual monitoring adaptive control

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Insight into Iron Leaching from an Ascorbate-Oxidase-like Fe-N-C Nanozyme and Oxygen Reduction Selectivity

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ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 2023年第27期62卷 e202302463-e202302463页

作者： Cao, xuwen Zhu, Caixia Hong, Qing chen, Xinghua Wang, Kaiyuan Shen, Yanfei Liu, Songqin Zhang, Yuanjian Southeast Univ Sch Chem & Chem Engn Jiangsu Engn Lab Smart Carbon Rich Mat & Device Jiangsu Prov Hitech Key Lab Biomed Res Nanjing 211189 Peoples R China Southeast Univ Med Sch Nanjing 210009 Peoples R China

Ascorbate (H(2)A) is a well-known antioxidant to protect cellular components from free radical damage and has also emerged as a pro-oxidant in cancer therapies. However, such "contradictory" mechanisms underlying H(2)A oxidation are not well understood. Herein, we report Fe leaching during catalytic H(2)A oxidation using an Fe-N-C nanozyme as a ferritin mimic and its influence on the selectivity of the oxygen reduction reaction (ORR). Owing to the heterogeneity, the Fe-N-x sites in Fe-N-C primarily catalyzed H(2)A oxidation and 4 e(-) ORR via an iron-oxo intermediate. Nonetheless, trace O-2(center dot-) produced by marginal N-C sites through 2 e(-) ORR accumulated and attacked Fe-N-x sites, leading to the linear leakage of unstable Fe ions up to 420 ppb when the H(2)A concentration increased to 2 mM. As a result, a substantial fraction (ca. 40 %) of the N-C sites on Fe-N-C were activated, and a new 2+2 e(-) ORR path was finally enabled, along with Fenton-type H(2)A oxidation. Consequently, after Fe ions diffused into the bulk solution, the ORR at the N-C sites stopped at H2O2 production, which was the origin of the pro-oxidant effect of H(2)A.

关键词： Antioxidants Iron Nanozymes Oxygen Reduction Selectivity Pro-Oxidants

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The Rigorous Derivation of the 2D Cubic Focusing NLS from Quantum Many-Body Evolution

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INTERNATIONAL MATHEMATICS RESEARCH NOTICES 2017年第14期2017卷 4173-4216页

作者： chen, xuwen Holmer, Justin Univ Rochester Dept Math Hylan Bldg Rochester NY 14627 USA Brown Univ Dept Math 151 Thayer St Providence RI 02912 USA

We consider a 2D time-dependent quantum system of N-bosons with harmonic external confining and attractive interparticle interaction in the Gross-Pitaevskii scaling. We derive stability of matter type estimates proving that the kth power of the energy controls the H1 Sobolev norm of the solution over k particles. This estimate is new and more difficult for attractive interactions than repulsive interactions. For the proof, we use a version of the finite-dimensional quantum de Finetti theorem from [47]. A high particle-number averaging effect is at play in the proof, which is not needed for the corresponding estimate in the repulsive case. This a priori bound allows us to prove that the corresponding BBGKY hierarchy converges to the GP limit as was done in many previous works treating the case of repulsive interactions. As a result, we obtain that the focusing nonlinear Schrdinger equation is the mean-field limit of the 2D time-dependent quantum many-body system with attractive interatomic interaction and asymptotically factorized initial data. An assumption on the size of the L1-norm of the interatomic interaction potential is needed that corresponds to the sharp constant in the 2D Gagliardo-Nirenberg inequality though the inequality is not directly relevant because we are dealing with a trace instead of a power.

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Scheduling optimization of AGVs in workshop based on cost-efficiency-emission competition mechanism

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2023年第20期237卷 4828-4839页

作者： chen, Ye Jing, xuwen Lu, Xiang Zhou, Honggen Li, Haipeng Kang, Chao Liu, Jinfeng Li, Jun Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang Peoples R China China Merchants Cruise Shipbldg Co Ltd Nantong Peoples R China Jiangsu Univ Sci & Technol Sch Mech Engn Mengxi Rd Zhenjiang 212013 Peoples R China

The untimely material transportation induced by the backward logistics scheduling method in the ship panel block construction workshop is a complex engineering issue with multi-parameter coupling. To overcome the problem, the cost-efficiency-carbon emission competition model is proposed to solve the scheduling optimization for the AGVs in ship panel block construction workshop. Firstly, the logistics path plan of the panel block construction workshop is obtained by establishing the path-planning node map of panel block construction workplace. Secondly, a scheduling model for AGVs is constructed based on the competition mechanism of the lowest transportation cost, maximum transportation efficiency, and lowest carbon emission. Then, the optimized schedule is achieved by a novel hybrid method of the genetic and population migration algorithm considering the competition mechanism. Finally, the case validation indicates that the solving ability of the proposed hybrid method is improved by 52.4% compared with Genetic Algorithm under competitive mechanism. Besides, the results demonstrate material transportation time can be reduced by 17.5%.

关键词： Scheduling optimization automatic guided vehicle competition mechanism similarity ship panel block

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Terrain Classification of PolSAR Images Based on Optimal Features Combination 3

Terrain Classification of PolSAR Images Based on Optimal Fea...

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3rd International Conference on Computer Vision, Image and Deep Learning and International Conference on Computer Engineering and Applications, CVIDL and ICCEA 2022

作者： Wang, Yangyang chen, Weidong Mao, xuwen chen, Chang University of Science and Technology of China 1School of Information Science and Technology Hefei China National University of Defense Technology Hefei China

ISBN: (纸本)9781665459112

Terrain classification of PolSAR images is an important research direction in remote sensing image interpretation. The effective extraction of useful information from the acquired PolSAR image has become a pressing challenge. In this paper, a terrain classification method of PolSAR images based on the optimal selection of polarization features and texture features is proposed. The method first extracts 96-dimensional polarization features and texture features of PolSAR image, then selects optimal features based on feature judgment factor, feature selection factor, and texture feature contrast, screens out 10-dimensional polarization features and texture features as training samples, and finally uses SVM method to realize terrain classification. The results show that the average classification accuracy of 6 types of terrain in the Flevoland dataset reaches more than 97% by using the proposed method, and the classification efficiency of terrains can be effectively improved without affecting the classification accuracy by selecting the optimal combination of polarization and texture features compared with using all features. © 2022 IEEE.

关键词： Polarization

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Experimental Study of the Reinforcement Mechanism for the Tunnel Support Structure in Weak Rock Masses

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INTERNATIONAL JOURNAL OF GEOMECHANICS 2023年第10期23卷 04023173-04023173页

作者： chen, Yulong Zhang, xuwen Qiao, Xuanru China Univ Min & Technol Sch Energy & Min Engn Beijing 100083 Peoples R China

This study aims to comprehensively investigate the reinforcement mechanism of the tunnel support structure and its supporting characteristics in layered and weak rock tunnels. Uniaxial compressive tests were carried out to study the mechanical and deformation characteristics of anchored rock with the system anchor bolt and the steel floral pipe. Besides, a three-point bending test of the steel-concrete composite beam was conducted to investigate the bending capacity of the grilles and I-beams. The experiment showed the following results: (1) The anchor bolt achieved the anchoring effect by improving the stress state and the strength of the surrounding rock. The improvement of the anchorage strength to the surrounding rock was reflected by the effect of the compression zone of preload, the healing effect of the anchorage agent on the surrounding rock, and the reinforcement effect of the anchor bolt on the density and strength of the anchor bolt. (2) By the CT scanning of the anchored samples after the experiment, it was found that the crack was blunted and arrested within the anchorage zone, and the crack-arresting effect was related to the range of the anchorage zone. The larger the anchorage zones, the better the crack-arresting effect. (3) The steel arch could effectively improve the ability of concrete antideformation. Compared with the lattice girder, the coordination ability of steel arch and concrete deformation was relatively weak. Its coordinate deformation stage was shorter than that of the lattice girder and earlier into the debonding stage. However, the stiffness of the steel arch and concrete was greater than that of the lattice girder after debonding and showed a strong bearing capacity.

关键词： Tunnel Support structure Uniaxial test Three-point bend test Anchorage mechanism

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乡贤参事会建设和运行标准化研究——以浙江省德清县为例

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中国质量与标准导报 2020年第5期 38-41页

作者：郑玲安然陈旭文朱明浙江省方大标准信息有限公司浙江省标准化研究院

以浙江省德清县乡贤参事会为例,剖析乡贤参事组织发展现状及问题,探讨乡贤参事会建设和运行标准化模式,为乡贤参事组织日常管理和工作开展提供有益借鉴和参考,推动乡村治理现代化,助力乡村振兴。

关键词：乡贤乡贤参事会乡村治理标准化

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High-quality chromosome-level genome assembly of the whitespotted conger (Conger myriaster)

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SCIENTIFIC DATA 2025年第1期12卷 1-9页

作者： Han, Shenglei Li, chen Li, Shuo chen, Yan Wang, chenggang Liu, Kaiqiang Liu, Yuyan Wang, Hong-Yan Wang, Qian Cao, xuwen Shi, Bao Shao, Changwei Jiangsu Ocean Univ Jiangsu Key Lab Marine Bioresources & Environm Lianyungang 222005 Peoples R China Chinese Acad Fishery Sci Yellow Sea Fisheries Res Inst State Key Lab Mariculture Biobreeding & Sustainabl Qingdao 266071 Shandong Peoples R China Qingdao Marine Sci & Technol Ctr Lab Marine Fisheries Sci & Food Prod Proc Qingdao 266237 Shandong Peoples R China Haiyang Yellow Sea Fisheries Co Ltd Yantai 265100 Peoples R China Chinese Acad Fishery Sci Hebei Key Lab Bohai Sea Fish Germplasm Resources C Beidaihe Cent Expt Stn Qinhuangdao 066100 Peoples R China

The whitespotted conger (Conger myriaster) is an ecologically and economically significant benthic marine species widely distributed across East Asia's coastal waters. Despite this importance, the genomic resources for this species remain limited, hindering evolutionary and aquaculture research. Here, we present the first high-quality chromosome-level genome assembly of C. myriaster using PacBio CLR, WGS, 10X Genomics and Hi-C data. The resulting 1.09 Gb genome assembly exhibits excellent contiguity, with 97.49% of sequences anchored onto 19 chromosomes. The assembled genome achieved a BUSCO completeness stands at 98.00%, containing 34.80% repetitive sequences and 24,063 predicted protein-coding genes. This foundational genomic resource overcomes a major limitation, providing the essential framework for future investigations into the evolutionary adaptations and for the genetic improvement of C. myriaster in aquaculture.

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Improved Vocal Tract Length Perturbation for Improving Child Speech Emotion Recognition

Improved Vocal Tract Length Perturbation for Improving Child...

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2023 International Conference on Sensing, Measurement and Data Analytics in the Era of Artificial Intelligence, ICSMD 2023

作者： Qu, Shenkang Qin, Yong Qin, xuwen Ren, Ziliang chen, Lei School of Computer Science and Technology Dongguan University of Technology Dongguan China Shenzhen International Exchange College Shenzhen China

ISBN: (纸本)9798350318012

Due to the variability of children's acoustic features during growth and the lack of a publicly available corpus of children's speech emotion data, training a robust children's Speech Emotion Recognition(SER) is more challenging than that of adults. We develop in this paper a new SER learning solution for children, which generates a child-like speech spectrum from an adult's speech spectrum based on vocal tract length normalization (VTLN) and vocal tract length perturbation (VTLP). This improved adult spectrum is then used as augmented data to improve the child speech emotion recognition system. To validate the effectiveness of this data augmentation method, we test it in two mainstream SER task networks based on Compact Convolutional Transformers(CCT) and Convolutional Neural Networks(CNN), respectively, and the proposed data augmentation method improves the accuracy and UAR by 0.32% and 0.22%, respectively, on the Fau Aibo children's emotion data corpus compared to the VTLP baseline system when trained with CCT. When trained with CNN, the accuracy and UAR are improved by 0.39% and 0.26%, respectively, compared to the VTLP baseline system. © 2023 IEEE.

关键词： Speech recognition

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