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

Multiple Tin Compounds Modified Carbon Fibers to Construct Heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption

引用

Nano-Micro Letters 2025年第1期17卷 507-527页

作者： Zhiqiang Guo Di Lan Zirui Jia Zhenguo Gao Xuetao Shi Mukun He Hua Guo Guanglei Wu Pengfei Yin College of Science Sichuan Agricultural UniversityYa’an 625014People’s Republic of China School of materials Science and engineering Hubei University of Automotive TechnologyShiyan 442002People’s Republic of China institute of materials for Energy and Environment State Key Laboratory of Bio‑Fibers and Eco‑TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China

Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly ***-component interface engineering is considered an effective means to achieve high-efficiency EMW ***,interface modulation engineering has not been fully discussed and has great potential in the field of EMW *** this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal *** utilizing the different properties of different substances,rich heterogeneous interfaces are *** effectively promotes charge transfer and enhances interfacial polarization and conduction *** prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy *** minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 ***,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel ***,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

关键词： Electrostatic spinning Component regulation Heterogeneous interfaces Electromagnetic wave absorption Corrosion protection

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

Wafer‑Scale Vertical 1D GaN Nanorods/2D MoS_(2)/PEDOT:PSS for Piezophototronic Effect‑Enhanced Self‑Powered Flexible Photodetectors

引用

Nano-Micro Letters 2025年第3期17卷 102-116页

作者： Xin Tang Hongsheng Jiang Zhengliang Lin Xuan Wang Wenliang Wang Guoqiang Li State Key Laboratory of Luminescent materials and Devices South China University of TechnologyGuangzhou 510640People’s Republic of China Department of Electronic materials School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640People’s Republic of China

van der Waals(vdW)heterostructures constructed by lowdimensional(0D,1D,and 2D)materials are emerging as one of the most appealing systems in next-generation flexible ***,hand-stacked vdW-type photodetectors are not compatible with large-areaarray fabrication and show unimpressive performance in self-powered ***,vertical 1D GaN nanorods arrays(NRAs)/2D MoS_(2)/PEDOT:PSS in wafer scale have been proposed for self-powered flexible photodetectors arrays *** as-integrated device without external bias under weak UV illumination exhibits a competitive responsivity of 1.47 A W^(−1)and a high detectivity of 1.2×10^(11)Jones,as well as a fast response speed of 54/71μs,thanks to the strong light absorption of GaN NRAs and the efficient photogenerated carrier separation in type-II ***,the strain-tunable photodetection performances of device have been ***,the device at−0.78%strain and zero bias reveals a significantly enhanced photoresponse with a responsivity of 2.47 A W^(−1),a detectivity of 2.6×10^(11)Jones,and response times of 40/45μs,which are superior to the state-of-the-art self-powered flexible *** work presents a valuable avenue to prepare tunable vdWs heterostructures for self-powered flexible photodetection,which performs well in flexible sensors.

关键词： Vertical nanorod arrays van der Waals heterostructure Piezophototronic effect Self-powered photodetection Flexible sensors

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

MXene Hybridized Polymer with Enhanced Electromagnetic Energy Harvest for Sensitized Microwave Actuation and Self‑Powered Motion Sensing

引用

Nano-Micro Letters 2025年第3期17卷 265-279页

作者： Yu‑Ze Wang Yu‑Chang Wang Ting‑Ting Liu Quan‑Liang Zhao Chen‑Sha Li Mao‑Sheng Cao School of materials Science and engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China School of materials Science and engineering Peking UniversityBeijing 100871People’s Republic of China School of Mechanical and Material engineering North China University of TechnologyBeijing 100144People’s Republic of China Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080People’s Republic of China

Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.

关键词： Microwave absorption Electromagnetic response Energy harvest Self-sensing Soft actuator

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

Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

引用

Science China Chemistry 2025年

作者： Yuan Tian Jiang-Bo Chen Jie Ying Ge Tian Yu-Xuan Xiao Yi Lu Si-Ming Wu Wei Geng Ling Shen Xiao-Yu Yang State Key Laboratory of Advanced Technology for materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology School of Chemical engineering and Technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

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

Design high-performance narrowband emitters for blue light-emitting diodes through manipulating resonance structure of aromatic heterocycles

引用

Science China Chemistry 2025年

作者： Yue Yu Lei Xu Wenle Tan Yuyu Pan Jiyin Xiao Bohan Wang Guangjun Tian Yuguang Ma Lei Ying institute of Polymer Optoelectronic materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials State Key Laboratory of Luminescent Materials and Devices South China University of Technology School of Petrochemical engineering Shenyang University of Technology Key Laboratory for Microstructural Material Physics of Hebei Province School of Science Yanshan University

Narrowband light-emitting materials play critical roles in improving the color gamut and energy consumption of electroluminescence. Herein we demonstrated that by regulating the ground state resonance structure form of emitters with polycyclic aromatic heterocycles, the high-energy vibration of the C–C bond can be effectively suppressed, resulting in narrow emission like classical cyanine dyes. The designed compounds consist of twist and planar conformation, while having differences in the orientation of the positioning electron-donating(nitrogen) and electron-accepting(carbonyl) groups in the polycyclic aromatic hydrocarbon skeleton. The resulting compound Ac-Ph-Ac with a dominated zwitterionic resonance structure exhibits a relatively wide electroluminescent profile with the full width at half maximum(FWHM) of 42 nm and moderate device performance. In contrast, the “soliton transition” of 2AcPh based on the cyanine limit character effectively suppresses C–C stretching vibration in the polycyclic aromatic heterocycle skeleton, leading to a narrow electroluminescent profile with FWHM of 30 nm(0.16 eV)associated with an impressively high external quantum efficiency of 28.52%, which is among the highest efficiencies of so far reported non-sensitized organic light-emitting diodes.

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

All-day solar power generation enabled by photo/thermoelectric conversion and thermal energy storage

引用

Science China Chemistry 2025年

作者： Zijian Liu Chengzhi Chen Junda Liu Qi Sun Bingchen Huo Chunyu Du Guangming Chen College of materials Science and engineering Shenzhen University

Thermoelectric materials hold promises for direct conversion of heat into electricity, making them viable power sources for electronic devices. However, their practical applications in diverse outdoor environment are hindered by limited and discontinuous electricity output. In this study, we propose an all-day solar power generator to achieve highly efficient and continuous electricity generation by harnessing the synergistic effects of photoelectric-thermoelectric conversion and latent thermal energy storage. The all-day solar power generator exhibits an average open-circuit voltage of 6.8 m V during daylight and a remaining 0.9 mV during nighttime. Importantly, the all-day solar power generator achieves dependable outdoor power supply for communication transmission in diverse environmental scenarios. Our research opens a new way for highly efficient and sustainable power generation.

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

Reverse modulation of defect density of Ce-MOF-808 by solventassisted ligand exchange for dicyclopentadiene hydrogenation

引用

Science China Chemistry 2025年

作者： Danfeng Zhao Fajie Hu Rushuo Li Xinmeng Xu Zhaokun Wang Zuoshuai Xi Jun Tong Xiubing Huang Ge Wang Advanced Innovation Center for materials Genome engineering Beijing Key Laboratory of Function Materials for Molecule & Structure Construction School of Materials Science and Engineering University of Science and Technology Beijing

Defect engineering is a pivotal strategy for tailoring the electronic structure and physicochemical properties of catalysts, yet the straightforward manipulation of defect density in porous materials presents a current challenge. In this work, we achieved precise control over the coordination unsaturated site（CUS） content and pore architecture of Ce-MOF-808 by employing 2-fluorobenzoic acid（2-FBA） as a modifier. Leveraging the p Kadisparities among three ligands（1,3,5-tricarboxylic benzoic acid,formic acid, and 2-FBA）, we preserved the spn topology of Ce-MOF within an aqueous system, while realizing partial substitution of the auxiliary ligands and saturation of the CUS. The amount of 2-FBA was negatively correlated with the number of ligand defects, and the consequent decrease in Ce3+content and the increase in the number of ligand linkages also induced crystal structure transformation. The modulation of the defect structure was correlated with the catalytic performance of dicyclopentadiene（DCPD） hydrogenation reaction, in which Ce-MMF0.15, constructed by the modulation of 0.15 mol amount of 2-fluorobenzoic acid, exhibited an optimal ligand defect density and micro-mesoporous structure, enabling almost complete conversion of DCPD at 100 ℃ and 2 MPa. This article also elucidates the correlation between the regulation of defect density and the accessibility of frustrated Lewis pair（FLP） active sites, guiding the application of novel porous intrinsic FLP materials in hydrogenation catalysis.

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

Transforming waste particles into valuable adsorbents via amyloid-mediated molecular engineering

引用

Science China Chemistry 2025年第1期68卷 317-328页

作者： Qingmin Yang Jian Zhao Yujia Zhang Xingyu Zhou Hao Ren Bowen Hu Zhongli Lei Lixin Chen Peng Yang School of Material and Chemical engineering Bengbu University Anhui Provincial engineering Laboratory of Silicon-Based materials School of Chemistry and Chemical engineering Northwestern Polytechnical University Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical EngineeringShaanxi Normal University Xi'an Key Laboratory of Polymeric Soft Matter School of Chemistry and Chemical Engineering Shaanxi Normal University International Joint research Center on Functional Fiber and Soft Smart Textile School of Chemistry and Chemical EngineeringShaanxi Normal University

The high-value utilization of industrial solid waste using a facile and eco-friendly process is of great interest and significance in reducing environmental pollution and developing a green circular economy. Herein, we propose an amyloid-mediated molecular engineering strategy to transform particulate waste into valuable adsorbents for metal ions. Our method has the advantage of aqueous solution fabrication under mild conditions without the use of high-temperature hydrothermal methods and toxic chemical reagents. Amyloid-mediated molecular engineering manipulates the phase transition of bovine serum albumin(BSA)on particulate waste surfaces, resulting in a remarkable ～3.1 times improvement in the adsorption capacity of fly ash, a typical industrial solid waste for gold ions after modification with the phase-transitioned BSA(PTB). The resultant adsorption ability was 69–1,980 times higher than those of conventional and emerging adsorbent materials such as ion exchange resins, activated carbon(AC), covalent organic frameworks(COFs), and metal-organic frameworks(MOFs). We further demonstrated the application of our PTB-modified materials in the recovery of precious metals from low-grade gold ore and electronic waste leachates. Consequently, this strategy could increase the value of waste materials nearly 27 times. In addition, this method is generally extendable to other conventional industrial adsorbents such as resin, clay, and Al2O3, and enhances their adsorption capabilities at least twofold. Overall, this work provides a simple and green approach for improving the adsorption performance of solid particles, and is expected to develop into a universal strategy for transforming waste particles into high-value-added products.

关键词： amyloid-like protein aggregates surface engineering fly ash solid waste adsorption

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

research on the balance optimization algorithm of image recognition accuracy and speed based on autocollimator measurement

引用

Optoelectronics Letters 2025年第2期21卷 121-128页

作者： LI Renpu MA Long CUI Jiwen GUO Junqi Andrei KULIKOV WEN Dandan Chongqing engineering research Center of Intelligent Sensing Technology and Microsystem Chongqing University of Post and Telecommunications School of Instrumentation Science and engineering Harbin Institute of Technology Higher School of engineering and Technology ITMO University

The autocollimator is an important device for achieving precise,small-angle,non-contact *** primarily obtains angular parameters of a plane target mirror indirectly by detecting the position of the imaging *** is limited report on the core algorithmic techniques in current commercial products and recent scientific *** paper addresses the performance requirements of coordinate reading accuracy and operational speed in autocollimator image *** proposes a cross-image center recognition scheme based on the Hough transform and another based on Zernike moments and the least squares *** experimental evaluation of the accuracy and speed of both schemes,the optimal image recognition scheme balancing measurement accuracy and speed for the autocollimator is *** these,the center recognition method based on Zernike moments and the least squares method offers higher measurement accuracy and stability,while the Hough transform-based method provides faster measurement speed.

关键词： Least squares approximations

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：