检索结果-南通市图书馆

Designing Electronic Structures of Multiscale Helical Converters for Tailored Ultrabroad Electromagnetic Absorption

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第1期17卷 439-455页

作者： Zhaobo Feng Chongbo Liu Xin Li Guangsheng Luo Naixin Zhai Ruizhe Hu Jing Lin Jinbin Peng Yuhui Peng Renchao Che key laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle School of Environmental and Chemical EngineeringNanchang Hangkong UniversityNanchang 330063People’s Republic of China School of Physics and materials Nanchang UniversityNanchang 330031People’s Republic of China key laboratory of Nondestructive Testing Ministry of EducationNanchang Hangkong UniversityNanchang 330063People’s Republic of China laboratory of Advanced materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering and TechnologyFudan UniversityShanghai 200438People’s Republic of China

Atomic-scale doping strategies and structure design play pivotal roles in tailoring the electronic structure and physicochemical property of electromagnetic wave absorption(EMWA)***,the relationship between configuration and electromagnetic(EM)loss mechanism has remained ***,drawing inspiration from the DNA transcription process,we report the successful synthesis of novel in situ Mn/N co-doped helical carbon nanotubes with ultrabroad EMWA *** calculation and EM simulation confirm that the orbital coupling and spin polarization of the Mn–N4–C configuration,along with cross polarization generated by the helical structure,endow the helical converters with enhanced EM *** a result,HMC-8 demonstrates outstanding EMWA performance,achieving a minimum reflection loss of−63.13 dB at an ultralow thickness of 1.29 *** precise tuning of the graphite domain size,HMC-7 achieves an effective absorption bandwidth(EAB)of 6.08 GHz at 2.02 mm ***,constructing macroscale gradient metamaterials enables an ultrabroadband EAB of 12.16 GHz at a thickness of only 5.00 mm,with the maximum radar cross section reduction value reaching 36.4 dB *** innovative approach not only advances the understanding of metal–nonmetal co-doping but also realizes broadband EMWA,thus contributing to the development of EMWA mechanisms and applications.

关键词： Metal-nonmetal co-doping 3d-2p orbital coupling Spin polarization Helical structure Broadband EM wave absorption

“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第1期17卷 348-360页

作者： Yan Zhao Qiang Yuan Liting Yang Guisheng Liang Yifeng Cheng Limin Wu Chunfu Lin Renchao Che College of Physics Donghua UniversityShanghai 201620People’s Republic of China School of materials Science and Engineering Institute of Materials for Energy and EnvironmentQingdao UniversityQingdao 266071People’s Republic of China laboratory of Advanced materials Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Zhejiang laboratory Hangzhou 311100People’s Republic of China Inner Mongolia University Hohhot 010021People’s Republic of China

Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte ***,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term ***,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical *** Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O *** superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

关键词： NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization

Synthesis,Structure and Adsorption of AlPO-21 Prepared by Co-template Method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2003年第12期21卷 1608-1614页

作者：张雷程晓维龙英才 shanghai key laboratory of molecular catalysis and innovative materials Fudan University

The phase of AlPO-21 was hydrothermally synthesized in the reactant system of diethylamine-RB-Al_2O_3-P_2O_5-H_2O-C_2H_5OH. The crystals of AlPO-21 growing in this system crystallizes in monoclinic system,space group P2_1/n with a=0.8542(4) nm,b=1.7635(8) nm,c=0.9082(4) nm,β=108.234(5)°,V=1.2993(10) nm 3,Z=4,and the formula is [C_4H_ 10 NH_2] +~[Al_3P_3O_ 12 (OH)] -. The structure is resolved by the direct method and refined to R_1=0.0767 and wR_2=0.1627 based on 1719 observed reflections with I>2.0σ(I). An asymmetric unit consists of three PO_4 tetrahedra,one AlO_4 tetrahedron and two AlO_5 trigonal bipyramids. The framework is composed of 3-D uniform channels along [100],[001] and [101] with eight-membered oxygen ring windows. The powder sample of the MS was investigated with powder XRD,TG/DTG/DTA and the adsorption of water,methanol,n-hexane,ethylene,and ethane. The specific property for sieving molecules was observed on the adsorption isotherms,and proves the result of the single crystal structural analysis.

关键词： AlPO-21 co-template method rhodamine B diethylamine Lowenstein rule

Lanthanide-catalyzed cyclocarbonylation and cyclothiocarbonylation: a facile synthesis of benzannulated 1,3-diheteroatom five- and six-membered heterocycles

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2014年第8期57卷 1117-1125页

作者： JING YuFeng LIU RuiTing LIN YangHui ZHOU XiGeng shanghai key laboratory of molecular catalysis and innovative material Department of Chemistry Fudan University State key laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry

La[N(SiMe3)2]3 proves to be an efficient catalyst system for the cyclocarbonylation of 1,2-disubstituted benzenes with isocyanates. In this approach, aryl/alkyl isocyanates react with o-phenylenediamine, o-aminophenol, o-aminothiophenol, catechols and anilines ortho-substituted by CH2NH2 and CONH2 to form, respectively, the corresponding benzimidazolones, benzoxazolones, benzothiazolones, benzodioxolones, 3,4-dihydroquinazolin-2(1H)-one, and quinazolinediones. These results represent the first example of lanthanide-catalyzed carbonylation. This methodology is also applicable for the preparation of various benzannulated 1,3-diheteroatom cyclic thioketones starting from aryl/alkyl isothiocyanates or CS2 in good to excellent yields. Based on the results of experiments performed using an o-aminobenzamido dianion lanthanide complex, a general mechanism, involving the tandem reaction of two lanthanide-ligand bonds with one heterocumulene molecule, is proposed as well.

关键词： lanthanide catalyst 1 2-disubstituted benzene isocyanate isothiocyanates cyclocarbonylation cyclothiocarbonylation

同方期刊数据库

Facile oxalic acid-assisted construction of laminated porous N-deficient graphitic carbon nitride: Highly efficient visible-light-driven hydrogen evolution photocatalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第6期28卷 1-8页

作者： Fengli Yang Jia Ren Qianqian Liu Lu Zhang Yuanyuan Chai Wei-Lin Dai Department of Chemistry & shanghai key laboratory of molecular catalysis and innovative materials Fudan University

The laminated porous N-deficient g-C3N4(CN–H)is successfully synthesized by a facile two-step hydrothermal calcination method using oxalic acid-assisted melamine as the *** with pristine g-C3N4(224μmol g-1h-1),the CN–H shows superior photocatalytic hydrogen production activity(up to 728μmol g-1h-1),which is three times higher than the unmodified *** draw out the multifaceted influences of oxalic acid modification on the visible-light-induced photocatalytic activity,various techniques are utilized to investigate the formation mechanism,structural characteristics and photoelectrical properties of CN–*** results indicate that the addition of a trace amount of oxalic acid to the precursor melamine results in a g-C3N4 structure possessing the advantage of both nitrogen defects and laminated *** properties can enlarge specific surface areas of g-C3N4,enhance an efficient separating of photogenerated electron-hole pairs and extend the range of spectral response,all contributing to the enhancement of the visible-light-induced photocatalytic activity.

关键词： Oxalic acid Melamine Laminated porous N-deficient g-C3N4 Visible-light-induced photocatalytic activity for H2 generation

Self-assembly of metalla[3]catenanes, Borromean rings and ring-in-ring complexes using a simple π-donor unit

在线全文

学校读者我要写书评

暂无评论

National Science Review 2020年第10期7卷 1548-1556页

作者： Ye Lu Dong Liu Yue-Jian Lin Zhen-Hua Li Guo-Xin Jin State key laboratory of molecular Engineering of Polymers Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsDepartment of Chemistry Fudan University

Despite extensive research and several stunning breakthroughs in the synthesis of interlocked molecular species, [3]catenanes, Borromean rings and ring-in-ring complexes are exceedingly rare and their targeted synthesis remains a formidable challenge. Herein, a series of Cp*Rh-based homogeneous and heterogeneous interlocked structures have been prepared by coordination-driven self-assembly, not only including metalla[2]catenanes and molecular Borromean rings, but also linear metalla[3]catenanes and ring-in-ring complexes. The interlocked structures are all based on bithiophenyl groups. The bithiophenyl groups effectively enhance the strength of the inter-ring interactions and play a crucial role in the formation of these interlocked structures. By taking advantage of the strong interaction between π-donor(D) andπ-acceptor(A) groups, the electron-deficient methylviologen cation was introduced into a cationic metallarectangle based on bithiophenyl groups. Taking inspiration from these results, a cationic metallarectangle based on A units was threaded into a metallarectangle based on D units, leading to a heterogeneous D–A ring-in-ring structure.

关键词： coordination-driven self-assembly supramolecular chemistry interlocked structure metallacatenanes molecular Borromean rings ring-in-ring complex

Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversion for efficient oxygen evolution reaction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2022年第7期16卷 1114-1124页

作者： Lingtao Kong Zhouxun Li Hui Zhang Mengmeng Zhang Jiaxing Zhu Mingli Deng Zhenxia Chen Yun Ling Yaming Zhou shanghai key laboratory of molecular catalysis and innovative materials Department of ChemistryFudan UniversityShanghai 200433China

Improvement of the low-cost transition metal electrocatalyst used in sluggish oxygen evolution reaction is a significant but challenging problem. In this study, ultrafine Fe-modulated Ni nanoparticles embedded in a porous Ni-doped carbon matrix were produced by the pyrolysis of zirconium metal–organic–frameworks, in which 2,2′-bipyridine-5,5′-dicarboxylate operating as a ligand can coordinate with Ni^(2+) and Fe^(3+). This strategy allows formation of Fe-modulated Ni nanoparticles with a uniform dimension of about 2 nm which can be ascribed to the spatial blocking effect of ZrO_(2). This unique catalyst displays an efficient oxygen evolution reaction electrocatalytic activity with a low overpotential of 372 mV at 10 mA·cm^(–2) and a small Tafel slope of 84.4 mV·dec^(–1) in alkaline media. More importantly, it shows superior durability and structural stability after 43 h in a chronoamperometry test. Meanwhile, it shows excellent cycling stability during 4000 cyclic voltammetry cycles. This research offers a new insight into the construction of uniform nanoscale transition metals and their alloys as highly efficient and durable electrocatalysts.

关键词： metal–organic framework pyrolysis ultrafine Fe-modulated Ni nanoparticles oxygen evolution reaction

Exploiting quasi-one-dimensional confinement for proficient hydrogen production from formic acid at room temperature

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2020年第10期29卷 205-213页

作者： Tao Jiang Peng Lu Meng-Jiao Xu Jian-Dong Lin Yong-Mei Liu Yong Cao He-Yong He shanghai key laboratory of molecular catalysis and innovative materials Department of ChemistryFudan UniversityShanghai 200433China

We describe herein that the quasi-one-dimensional confinement effect of functionalized nanoporous supports is particularly advantageous for boosting formic acid(FA)dehydrogenation efficiency over palladium nanoparticles(NPs).Benefiting from their unique structural merits that lead to significant lowering of the entropic barrier for FA activation,the Pd NPs interiorly located on the amino-modified MCM-41 offer the promise of more than an order of magnitude speedup of the initial activity in H2 production from FA over their exterior *** mild and additive-free conditions,ultrafine Pd NPs confined in aminomodified MCM-41 channels exhibit an initial turnover frequency as high as 46,677 h-1 and a turnover number up to 1,060,000 at 60℃.In conjunction with the enhancement and robust performance for efficient regeneration of FA via CO2 hydrogenation,the presented approach greatly contributes to the development of FA-based hydrogen storage and related technologies as viable means of enabling sustainable future energy prospects.

关键词： Confinement effect Formic acid Heterogeneous catalysis Hydrogen storage

Fluorescent carbon dots synthesized in solid phase and air for application in LEDs

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8495-8503页

作者： Wei-Jie Zheng Zhao-Nan Sun Yi-Ming Wang Huan-Ming Xiong Department of Chemistry and shanghai key laboratory of molecular catalysis and innovative materials Fudan UniversityShanghai 200438China

Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent ***,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and ***-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of *** this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs *** the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in *** production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction *** IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these *** dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to *** the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.

关键词： carbon dot solid-phase synthesis white LED photoluminescence inorganic salt catalysis