检索结果-南通市图书馆

Persistent radical anion of perylene dianhydride:an emerging metal-free photocatalyst for near-infrared photocontrolled RAFT polymerization

引用

Science China Chemistry 2024年第2期67卷 677-686页

作者： Haitao Zhao Guoqing Bian Xiang Xu Weiwei He Lifen Zhang Zhenping Cheng State and Local Joint Engineering laboratory for Novel Functional Polymeric materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Developing a new type of photocatalyst(PC) and catalytic mechanism for near-infrared(NIR) photocontrolled reversibledeactivation radical polymerization(RDRP) system is charming but challenging.Herein,a novel PC of the persistent radical anion(PRA)(possessing the properties of both radical and anion) was developed for NIR photocontrolled reversible additionfragmentation chain transfer(RAFT) polymerization,enabling successful polymerization while gaining a deep insight into the mechanism of photo-induced electron transfer RAFT(PET-RAFT) polymerization.Different from the conventional and wellaccepted reductive quenching(RQ) pathway,in which the radical anion intermediates of PCs(PCs^(·-)) must be generated in an excited state(ES),here,the PRA(3,4,9,10-perylenetetracarboxylic dianhydride radical anion(PTCDA^(·-))) could generate conveniently in situ in the ground state(GS) and subsequently serve as highly efficient PC in the NIR region(740–850 nm).The successful implementation of this strategy elucidates the peculiar role played by light and the real way of electron transfer behaviors.In fact,the transfer of a single electron from PRA to chain transfer agent(CTA) and cleavage of the C–S bonds is a process from ES to GS,rather than always from GS(PCs^(·-)) to GS(CTA) in the RQ pathway as is well known to all.In addition,the excellent spatial-temporal control and powerful penetration ability of the NIR light were also confirmed by this PRAcatalyzed polymerization system.

关键词： photocatalyst persistent radical anion(PRA) near-infrared(NIR)light reversible-deactivation radical polymerization(RDRP) photo-induced electron transfer RAFT(PET-RAFT)polymerization

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

Tuning the reactivity of TiO_(2)layer with uniform distribution of Sub-5 nm Fe_(2)O_(3)particles via in situ voltage-assisted oxidation for robust catalytic reduction

引用

Nano materials Science 2024年第2期6卷 223-234页

作者： Nisa Nashrah Abdelkarim Chaouiki Wail Al Zoubi Young Gun Ko integrated materials Chemistry laboratory School of Materials Science and EngineeringYeungnam UniversityGyeongsan38541Republic of Korea

The trade-off between efficiency and stability has limited the application of TiO_(2)as a catalyst due to its poor surface reactivity.Here,we present a modification of a TiO_(2)layer with highly stable Sub-5 nm Fe_(2)O_(3)nanoparticles(NP)by modulating its structure-surface reactivity relationship to attain efficiency-stability balance via a voltage-assisted oxidation approach.In situ simultaneous oxidation of the Ti substrate and Fe precursor using high-energy plasma driven by high voltage resulted in uniform distribution of Fe_(2)O_(3)NP embedded within porous TiO_(2)layer.Comprehensive surface characterizations with density functional theory demonstrated an improved electronic transition in TiO_(2)due to the presence of surface defects from reactive oxygen species and possible charge transfer from Ti to Fe;it also unexpectedly increased the active site in the TiO_(2)layer due to uncoordinated electrons in Sub-5 nm Fe_(2)O_(3)NP/TiO_(2)catalyst,thereby enhancing the adsorption of chemical functional groups on the catalyst.This unique embedded structure exhibited remarkable improvement in reducing 4-nitrophenol to 4-aminophenol,achieving approximately 99%efficiency in 20 min without stability decay after 20 consecutive cycles,outperforming previously reported TiO_(2)-based catalysts.This finding proposes a modified-electrochemical strategy enabling facile construction of TiO_(2)with nanoscale oxides extandable to other metal oxide systems.

关键词： Titanium dioxide Oxide nanoparticle Electrochemical oxidation Surface reactivity Efficiency Stability

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Progress on the program of Si-compatible two-dimensional semiconductor materials and devices

引用

Science China(Information Sciences) 2024年第6期67卷 152-171页

作者： Mingsheng XU Yuwei WANG Jiwei LIU Deren YANG College of integrated Circuits State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University School of materials Science and Engineering State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University

Two-dimensional(2D) materials are at the forefront of innovation, heralding a new era for nextgeneration electronics and optoelectronics. These materials are distinguished by their unique structural characteristics: they have no hanging bonds on their surface, exhibit weakened electrostatic shielding in the Z-direction, and boast atomic thickness in their monolayers. These features have led to groundbreaking discoveries in electrical, optical, and magnetic properties, paving the way for advancements in low-power electronics, valleytronics, infrared detectors, and memory devices. Despite these promising developments,Si-based technologies continue to dominate the landscape of next-generation electronics and optoelectronics,as well as heterogeneous integration. In response to this ongoing evolution, the National Natural Science Foundation of China(NSFC) initiated a major program in 2021 dubbed “Si-compatible two-dimensional semiconductor materials and devices”. This study reviews the progress made under the NSFC Program,spotlighting its main achievements and outlining key future research directions. Additionally, it sheds light on the challenges that researchers in the 2D domain face, particularly in developing Si-compatible 2D technologies.

关键词： two-dimensional materials Si-based CMOS technologies electronics and optoelectronics heterogeneous integration low-power

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

Moiré superlattices arising from growth induced by screw dislocations in layered materials

引用

Chinese Physics B 2024年第7期33卷 72-77页

作者：田伏钰 Muhammad Faizan 贺欣孙远慧张立军 State Key laboratory of integrated Optoelectronics Key laboratory of Automobile materials of MOE and College of materials Science and Engineering Jilin UniversityChangchun 130012China Suzhou laboratory Suzhou 215123China

Moiré superlattices(MSLs) are modulated structures produced from homogeneous or heterogeneous two-dimensional layers stacked with a twist angle and/or lattice mismatch. Enriching the methods for fabricating MSL and realizing the unique emergent properties are key challenges in its investigation. Here we recommend that the spiral dislocation driven growth is another optional method for the preparation of high quality MSL samples. The spiral structure stabilizes the constant out-of-plane lattice distance, causing the variations in electronic and optical properties. Taking SnS_2 MSL as an example, we find prominent properties including large band gap reduction(~ 0.4 e V) and enhanced optical activity. Firstprinciples calculations reveal that these unusual properties can be ascribed to the locally enhanced interlayer interaction associated with the Moiré potential modulation. We believe that the spiral dislocation driven growth would be a powerful method to expand the MSL family and broaden their scope of application.

关键词： Moirésuperlattices interlayer interaction spiral dislocation layered materials

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

Discontinuous phase diagram of amorphous carbons

引用

National Science Review 2024年第4期11卷 164-171页

作者： YinBo Zhu ZhouYu Fang ZhongTing Zhang HengAn Wu CAS Key laboratory of Mechanical Behavior and design of materials Department of Modern MechanicsUniversity of Science and Technology of China State Key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

The short-range order and medium-range order of amorphous carbons demonstrated in experiments allow us to rethink whether there exist intrinsic properties hidden by atomic disordering. Here we presented six representative phases of amorphous carbons（0.1–3.4 g/cm3）, namely, disordered graphene network（DGN）, high-density amorphous carbon（HDAC）, amorphous diaphite（a-DG）, amorphous diamond（a-D）, paracrystalline diamond（p-D）, and nano-polycrystalline diamond（NPD）, respectively, classified by their topological features and microstructural characterizations that are comparable with experiments. To achieve a comprehensive physical landscape for amorphous carbons, a phase diagram was plotted in the sp3/sp2versus density plane, in which the counterintuitive discontinuity originates from the inherent difference in topological microstructures, further guiding us to discover a variety of phase transitions among different amorphous carbons. Intriguingly, the power law, log（sp3/sp2） ∝ ρn, hints at intrinsic topology and hidden order in amorphous carbons, providing an insightful perspective to reacquaint atomic disorder in non-crystalline carbons.

关键词： amorphous carbons disordered carbons phase diagram microstructural topology phase transition

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

High-frequency magnetic properties of biphase Ce_(2)Fe_(17)N_(3)/α-Fe microflakes with easy-plane anisotropy

引用

Journal of Rare Earths 2024年第1期42卷 110-115,I0004页

作者： Ke Wang Hang Zhang Yuandong Huang Zhibiao Xu Fashen Li Tao Wang Key laboratory for Magnetism and Magnetic materials of MOE Lanzhou UniversityLanzhou730000China Key laboratory of Special Function materials and Structure design Ministry of EducationLanzhou UniversityLanzhou730000China

Soft magnetic composites(SMCs)are effective as magnetic powder cores in an inductor.Due to high saturation magnetization,large magnetocrystalline anisotropy and high operating frequency of M(metal)-RE(rear earth)soft magnetic composites,it is possible to miniaturize inductor cores by reducing total loss,especially eddy current loss and excess loss at high frequencies.In this article,the characteristics of Ce_(2)Fe_(17)N_(3)/α-Fe(CFN/F)loss per volume and effective permeability reaching a high frequency of 3 MHz are investigated.The biphase CFN/F composite exhibits a high permeability of 16 at 70 MHz,which is two times greater than that of pure Ce_(2)Fe_(17)N_(3)(CFN)powders.The total loss is as low as 545 mW/cm^(3)at 3 MHz and 6 mT.The direct current(DC)-bias properties have a percent of permeability exceeding 65% at H=7960 A/m.This phenomenon indicates that our material has a higher working frequency and lower core loss than other materials;the biphase CFN/F structure is a promising and efficient approach for developing the miniaturized radio frequency(RF)inductor core.

关键词： High frequency Soft magnetic composites Easy-plane anisotropy Permeability spectra Core loss Rare earths

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

Achieving high carrier mobility and low lattice thermal conductivity in GeTe-based alloys by cationic/anionic co-doping

引用

Rare Metals 2024年第6期43卷 2784-2795页

作者： Xiao-Qiang Wang Xiao-Quan Hu Jun-Yan Lin Chu-Bin Li Xiao-Tong Yu Qi-Yong Chen Li-Li Xi Qi-Shuo Yang Han Li Ji-Ye Zhang Shuan-Kui Li Kai Guo School of Physics and materials Science Guangzhou University Research Center for Advanced Information materials (CAIM) Huangpu Research & Graduate School of Guangzhou University School of materials Science and Engineering Shanghai University materials Genome Institute Shanghai University School of Mechanical and Mining Engineering University of Queensland Key laboratory of Si-Based Information materials & Devices and integrated Circuits design Department of Education of Guangdong Province

The Ⅳ-Ⅵ compound GeTe is considered as a promising alternative to the toxic PbTe for high-efficiency mid-temperature thermoelectric applications.However,pristine GeTe suffers from a high concentration of Ge vacancies,resulting in an excessively high hole concentration(> 1 × 1021cm-3),which greatly limits its thermoelectric enhancement.To address this issue,CuBiTe2alloying is introduced to increase the formation energy of Ge vacancies in GeTe,thereby inhibiting the high carrier concentration.The carrier scattering caused by the electronegativity difference between different elements is suppressed due to the similar electronegativity of Cu and Ge atoms.A relatively high hole mobility is obtained,which ultimately leads to a high power factor.Additionally,by introducing Se as an alloying element at the anionic site in GeTe,dense point defects with mass/strainfield fluctuations are induced.This contributes to the strengthening of phonon scattering,thereby reducing the lattice thermal conductivity from 1.44 W·m-1·K-1for pristine GeTe to 0.28 W·m-1·K-1for Ge0.95Cu0.05Bi0.05Te0.9Se0.15compound at 623 K.

关键词： GeTe Carrier mobility CuBiTe 2 alloying Lattice thermal conductivity Thermoelectric properties

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

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

引用

National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing Ma Linlin Duan Yuzhu Ma Wei Zhang Changlin Zheng Dongliang Chao Fei Wang Yongyao Xia Wei Li Department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University State Key laboratory of Surface Physics and Department of Physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable challenge.Herein,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as templates.The key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon matrix.The mesoporous Li2TiSiO5anode achieves a superior rate capability(148 mAh g-1at5.0 A g-1) and outstanding long-term cycling stability(138 mAh g-1after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-10 nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion lengths.This method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

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

Angular and planar transport properties of antiferromagnetic V5S8

引用

Chinese Physics B 2024年第2期33卷 83-88页

作者：吴晓凯王彬吴德桐陈博文弭孟娟王以林沈冰 Center for Neutron Science and Technology and School of Physics Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devicesand Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-Sen University School of integrated Circuits Shandong Technology Center of Nanodevices and Integration State Key Laboratory of Crystal MaterialsShandong University

Systemically angular and planar transport investigations are performed in layered antiferromagnetic(AF) V5S8. In this AF system, obvious anomalous Hall effect(AHE) is observed with a large Hall angle of 0.1 compared to that in ferromagnetic(FM) system. It can persist to the temperatures above AF transition and exhibit strong angular field dependence.The phase diagram reveals various magnetic states by rotating the applied field. By analyzing the anisotropic transport behavior, magnon contributions are revealed and exhibit obvious angular dependence with a spin-flop vanishing line. The observed prominent planar Hall effect and anisotropic magnetoresisitivity exhibit two-fold systematical angular dependent oscillations. These behaviors are attributed to the scattering from spin–orbital coupling instead of nontrivial topological origin. Our results reveal anisotropic interactions of magnetism and electron in V5S8, suggesting potential opportunities for the AF spintronic sensor and devices.

关键词： antiferromagnetism planar Hall effect magnetic and topological properties

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

Polymer Mechanochemistry on Reactive Species Generated from Mechanochemical Reactions

引用

Chinese Journal of Chemistry 2024年第12期42卷 1418-1432页

作者： Xiaolong Chen Hang Shen Zhengbiao Zhang State and Local Joint Engineering laboratory for Novel Functional Polymeric materials Suzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu 215123China

Comprehensive Summary Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years,as the mechanochemical generation of reactive species has a great potential in developing different polymeric materials for various purposes,such as stress detection,self-healing,self-strengthening,controllable degradation and release of small molecules.In this review,we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of mechanophores.Five types of reactive species,including radical,zwitterion,ionic,carbene and neutral intermediates,and their applications were reviewed in detail.Since mechanochemical reactions are sensitive to the mechanophore structure and polymer framework,we then discuss how mechanophore isomerism,polymer structure,polymer attachment point,and polymer architecture influence the mechanophore activation.At last,we provide our perspectives on the polymer mechanochemistry of reactivespecies.

关键词： Stimuli-responsive polymers Polymer mechanochemistry Mechanophore Mechanochemical reaction Reactive species

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

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：