检索结果-南通市图书馆

Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

Science China Chemistry 2025年第1期68卷 134-151页

作者： Jing Niu Shutao Xu Yingxu Wei Zhongmin Liu National engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of Sciences State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The methanol-to-olefins（MTO） reaction offers an alternative pathway for the production of low-carbon olefins from non-oil feedstocks. Fundamental research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in industry. In-situ solid-state nuclear magnetic resonance（ss NMR） spectroscopy has emerged as a pivotal tool, offering crucial insights into key species under real-time operando conditions. Furthermore, the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ13C MAS NMR and 2D correlation spectroscopy. Moreover, recent technological advancements in hyperpolarization（HP） methods, including HP129Xe NMR and dynamic nuclear polarization（DNP）, have significantly improved the sensitivity of ss NMR, enabling detailed structural and kinetic analysis as well as the detection of trace species. In this feature article, we summarized recent advancements in（in-situ） ss NMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest interactions. These theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts, thereby advancing the techniques towards more sustainable and economical production route for olefins.

关键词： MTO zeolites in-situ ssNMR reactive intermediates reaction mechanism

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A surface engineering strategy for the stabilization of zinc metal anodes with montmorillonite layers toward long-life rechargeable aqueous zinc ion batteries

引用

Journal of Energy Chemistry 2025年第1期100卷 94-105页

作者： Wenbo Wang Ruifeng Xu Xu Zhang Peiyu Wang Bao Yang Bingjun Yang Juan Yang Kailimai Su Pengjun Ma Yanan Deng Xianfeng Fan Wanjun Chen Key Laboratory for Electronic Materials College of Electrical Engineering Northwest Minzu University Resource Chemistry and Energy Materials Research Center State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences institute for Materials and Processes School of Engineering University of Edinburgh

Rechargeable aqueous zinc-ion batteries （AZIBs） exhibit appreciable potential in the domain of electrochemical energy ***,there are serious challenges for AZIBs,for instance zinc dendrite growth,hydrogen evolution reaction （HER）,and corrosion side ***,we propose a surface engineering modification strategy for coating the montmorillonite （MMT） layer onto the surface of the Zn anode to tackle these issues,thereby achieving high cycling stability for rechargeable *** results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration,facilitating the reaction kinetics of zinc *** functional theory（DFT） calculations and water contact angle （CA） tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn2+and better hydrophobicity than the bare Zn anode,thereby achieving excellent cycling ***,the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm-2and 0.125 m A h cm-2,even exceeding 1800 h long cycling under harsh conditions of 5 m A cm-2and 1.25 m A h *** MMT@Zn||V2O5full cell reaches over 3000 cycles at 2 A g-1with excellent rate ***,this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.

关键词： Hydrogen evolution reaction

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Emerging trends in the selective production of value-added aromatics

引用

Science China Chemistry 2025年第1期68卷 15-20页

作者： Yuchao Wu Houliang Dai Weisheng Yang Yaxing Li Lichen Liu Petrochemical Research institute Company Limited China National Petroleum Corporation engineering Research Center of Advanced Rare Earth Materials Department of Chemistry Tsinghua University

1 Introduction Aromatics (mainly benzene, toluene, and xylenes, BTX) are essential intermediates in the chemical industry. They are employed in the synthesis of a broad spectrum of chemicals and materials, e.g., various polymers, plastics, resins, solvents, dyes, pharmaceuticals [1]. The manufacturing pathway of BTX mainly includes petroleum reforming of naphtha, coal-to-aromatics, methanol-to-aromatics [2].

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Intrumer:A Multi Module Distributed Explainable IDS/IPS for Securing Cloud Environment

引用

Computers, Materials & Continua 2025年第1期82卷 579-607页

作者： Nazreen Banu A S.K.B.Sangeetha Department of Computer Science and engineering SRM Institute of Science and TechnologyVadapalani CampusChennai600026Tamil NaduIndia

The increasing use of cloud-based devices has reached the critical point of cybersecurity and unwanted network *** environments pose significant challenges in maintaining privacy and *** approaches,such as IDS,have been developed to tackle these ***,most conventional Intrusion Detection System(IDS)models struggle with unseen cyberattacks and complex high-dimensional *** fact,this paper introduces the idea of a novel distributed explainable and heterogeneous transformer-based intrusion detection system,named INTRUMER,which offers balanced accuracy,reliability,and security in cloud settings bymultiplemodulesworking together within *** traffic captured from cloud devices is first passed to the TC&TM module in which the Falcon Optimization Algorithm optimizes the feature selection process,and Naie Bayes algorithm performs the classification of *** selected features are classified further and are forwarded to the Heterogeneous Attention Transformer(HAT)*** this module,the contextual interactions of the network traffic are taken into account to classify them as normal or malicious *** classified results are further analyzed by the Explainable Prevention Module(XPM)to ensure trustworthiness by providing interpretable *** the explanations fromthe classifier,emergency alarms are transmitted to nearby IDSmodules,servers,and underlying cloud devices for the enhancement of preventive *** experiments on benchmark IDS datasets CICIDS 2017,Honeypots,and NSL-KDD were conducted to demonstrate the efficiency of the INTRUMER model in detecting network trafficwith high accuracy for different *** outperforms state-of-the-art approaches,obtaining better performance metrics:98.7%accuracy,97.5%precision,96.3%recall,and 97.8%*** results validate the robustness and effectiveness of INTRUMER in securing diverse cloud environments against sophisticated cyber threats.

关键词： Cloud computing intrusion detection system transformers and explainable artificial intelligence(XAI)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Innovative dual-mode device integrating capacitive desalination and solar vapor generation for high-efficiency seawater desalination

引用

Journal of Energy Chemistry 2025年第1期100卷 171-179页

作者： Jiacheng Wang Zhaoyu Chen Ruduan Yuan Jiaxin Luo Ben Zhang Keju Ji Meng Li Juanxiu Xiao Kuan Sun National Innovation Center for Industry-Education Integration of Energy Storage Technology MOE Key Laboratory of Low-grade Energy Utilization Technologies and SystemsCollege of Energy & Power Engineering Chongqing University Xuefeng Mountain Energy Equipment safety National Observation and Research Station CQU-NUS Renewable Energy Materials & Devices Joint Laboratory Chongqing University Southwest Technology and engineering Research institute Jiangsu Provincial Key Laboratory of Bionic Functional Materials College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Marine Resources Utilization in South China Sea Collaborative Innovation Center of Marine Science and Technology School of Marine Science and Engineering Hainan University

Solar-driven interface evaporation with high solar-to-steam conversion efficiency has shown great potential in seawater ***,due to the influence of latent heat and condensation efficiency,the water yield from solar-driven interface evaporation remains insufficient,posing a significant challenge that requires *** this work,we designed a dual-mode high-flux seawater desalination device that combines solar-driven interface evaporation and capacitive *** utilizing coupled desalination materials exhibiting both photothermal conversion and capacitance activity,the device demonstrated photothermal evaporation rates of 1.41 and 0.97 kg m-2h-1for condensate water yield under one-sun ***,the device exhibited a salt adsorption capacity of up to48 mg g-1and a salt adsorption rate of 2.1 mg *** addition,the salt adsorption capacity increased by approximately 32% under one-sun ***,photo-enhanced capacitive desalination performance was explored through numerical simulations and theoretical *** calculations and characterizations confirmed that the defect energy levels formed by the introduction of sulfur vacancies can effectively widen the light absorption range,improve photothermal conversion performance,and stimulate more photoelectrons to participate in capacitive ***,the electron distribution state of molybdenum disulfide with sulfur vacancies and surface defect sites contributes to ion/electron transport at the solid-liquid *** work provides a novel pathway for integrating solar vapor generation with other low-energy desalination technologies.

关键词： Desalination

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Situation-adaptive neural network for fast pre-computing image enhancement

引用

Science China(Information Sciences) 2025年

作者： Xinyue LI Huiyu DUAN Jia WANG Xiaohong LIU Yitong CHEN Guangtao ZHAI institute of Image Communication and Network engineering Department of Electronic EngineeringShanghai Jiao Tong University

As intelligent vision tasks become more widespread, enhancing image quality before further computational analysis is crucial. Recently, deep learning has shown potential for automated pre-computing enhancement, but it typically requires substantial computational resources and is hard to adapt to in multiple situations without *** practice, image enhancement often demands flexible adjustments based on different situations and subsequent computation devices, such as optical computing. Therefore,we propose SAEnhancer, a situation-adaptive neural network for fast pre-computing image enhancement. It learns from a small sample set to achieve personalized and adaptive enhancements for various situations without re-training,using semantic-aware embedding for precise color adjustments, surpassing traditional 3D lookup tables (LUTs), and enhancing computational effectiveness in intelligent vision applications.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Semantic Segmentation of Lumbar Vertebrae Using Meijering U-Net(MU-Net)on Spine Magnetic Resonance Images

引用

Computer Modeling in engineering & Sciences 2025年第1期142卷 733-757页

作者： Lakshmi S V V Shiloah Elizabeth Darmanayagam Sunil Retmin Raj Cyril Department of Computer Science and engineering College of Engineering GuindyAnna UniversityChennai600025India Department of Information Technology Madras Institute of TechnologyAnna UniversityChrompetChennai600044India

Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people *** to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the *** semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar *** is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation *** work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra ***-colour mask images were generated and used as ground truth for training the *** work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley *** proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.

关键词： Computer aided diagnosis(CAD) magnetic resonance imaging(MRI) semantic segmentation lumbar vertebrae deep learning U-Net model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

引用

Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram Kim Myeong‑Chang Sung Gwang‑Hee Lee Byoungjoon Hwang Sojung Seo Ji‑Hun Seo Dong‑Wan Kim Department of Materials Science and engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Integrated Equipment with Functions of Current Flow Control and Fault Isolation for Multiterminal DC Grids

引用

Energy engineering 2025年第1期122卷 85-99页

作者： Shuo Zhang Guibin Zou School of Electrical engineering Shandong UniversityJinan250061China Suzhou Research institute Shandong UniversitySuzhou215123China

The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable *** the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and ***,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power *** solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent *** addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC *** order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC ***,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.

关键词： Integrated equipment multiterminal direct current grid current flow control fault isolation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

引用

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： Fan YANG Zhaoyang MA Xingming GUO Shanghai Key Laboratory of Mechanics in Energy engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

关键词： Vibration analysis

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：