检索结果-内蒙古大学图书馆

Living Crystallization-Driven Self-Assembly of Oligo(p-phenylene vinylene)-Containing Block Copolymers:Impact of Branched Structure of Alkyl Side Chain ofπ-Conjugated Segment

引用

Chinese Journal of Polymer science 2023年第4期41卷 574-584,I0008页

作者： Yang Song Bo Xiang Xiao-Yu Huang Guo-Lin Lu Chun Feng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai200093China Shanghai Key Laboratory of Advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032China

The structure of side chains ofπ-conjugated segments is a critical factor determining living crystallization-driven self-assembly(CDSA),a versatile platform to generate fiber-like nanostructures with precise length and ***,we design and synthesize three block copolymers(BCPs)containing same corona-forming poly(N-isopropyl acrylamide)(PNIPAM)segment,but different core-formingπ-conjugated oligo(p-phenylene vinylene)(OPV)with linear pentyl(l-OPV),racemic 2-methyl butyl(r-OPV)and stereo-regular chiral(S)-2-methyl butyl(c-OPV)side chains,*** using these BCPs of l-OPV-b-PNIPAM_(47),r-OPV-b-PNIPAM_(47)and c-OPV-b-PNIPAM_(47)as model,we aim to get a deep insight into how steric and stereo-regular effect induced by branched alkyl side chains of OPV segment affects the living *** results showed that l-OPV-b-PNIPAM_(47)exhibits typical characteristics of self-seeding and seeded growth of living CDSA to give uniform fiber-like micelles of controlled *** the contrary,r-OPV-b-PNIPAM_(47)and c-OPV-b-PNIPAM_(47)with branched racemic and stereo-regular chiral alkyl side chains are more prone to self-nucleation during the micellar elongation to give short and polydisperse fiber-like *** obvious selfnucleation during the micellar elongation of r-OPV-b-PNIPAM_(47)and c-OPV-b-PNIPAM_(47)is due to the increase of steric repulsion with OPV units induced by branched alkyl side chains,not the stereo-irregular effect of racemic alkyl side chains.

关键词： π-Conjugated polymer Nanofiber Living crystallization-driven self-assembly Structure effect

来源：评论

学校读者我要写书评

暂无评论

Effect of sintering temperature on microstructure and properties of 3D printing polysilazane reinforced Al_(2)O_(3)core

引用

China Foundry 2023年第5期20卷 387-394页

作者： Wen-jun Dong Qiao-lei Li Tian-ci Chen Ming-ke Zou Jing-jing Liang Li-rong Liu Hui Mei Jin-guo Li School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Space Manufacturing Technology(CAS Key Lab) Beijing 100094China Science and Technology on Thermostructural Composite Materials Laboratory School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China

Ceramic cores are the key intermediate components of hollow blades for *** processes,such as hot-press molding and gel film casting,face difficulties in fabricating complex-structured ceramic cores due to the complexity of moulds and long process *** 3D printing provides a new idea for the fabrication of complex-structured ceramic *** effect of sintering temperature on open porosity,bulk density,weight loss rate,shrinkage rate,flexural strength and microstructure of the Al_(2)O_(3)-based ceramic core doped with 10vol.%polysilazane(PSZ)was *** sintering mechanism of PSZ-reinforced ceramic cores was *** show that the optimum sintering temperature of PSZ-reinforced ceramic cores is 1,450°*** this temperature,the open porosity of the ceramic core is 36.60%,bulk density is 2.33 g·cm^(-3),weight loss rate is 22.11%,shrinkage rate along the X,Y,Z directions is 5.72%,5.01%,9.61%,respectively;the flexural strength is 28.794 MPa at 25°C and 13.649 MPa at 1,500°*** of 3D printing PSZ-reinforced ceramic cores can meet the casting requirement of superalloy hollow blades,which is expected to promote the industrial application of 3D printing complex structure ceramic cores.

关键词： investment casting ceramic core 3D printing sintering temperature flexural strength

来源：评论

学校读者我要写书评

暂无评论

Near-infrared long-lifetime emission via triplet-to-singlet F?rster resonance energy transfer

引用

Green Chemical Engineering 2025年第1期6卷 1-5页

作者： Ruihong Liu Dongzhi Liu Xiang Ma Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou215123China School of Chemical Engineering and Technology Collaborative Innovation Center of Chemical Science and EngineeringTianjin Engineering Research Center of Functional Fine ChemicalsTianjin UniversityTianjin300072China Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Frontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237China

Here,an innovative approach to achieve near-infrared(NIR)long-lived circularly polarized luminescence(CPL)in amorphous organic polymer materials was *** co-doping bi-naphthalene derivative R/S-BPN as energy donors with porphyrin derivative TPPOH as energy acceptor into PVA polymer matrix,the NIR long-lifetime fluorescence was successfully realized through the principles of triplet-to-singlet F?rster resonance energy transfer(TS-FRET).Photophysical characterizations revealed distinct room temperature phosphorescence(RTP)emission peaks and phosphorescence lifetimes for different donor-acceptor *** TS-FRET process facilitated extended lifetime and red-shifted emission of the acceptor ***,employing the chiral donor R/S-BPN as chiral seeds to establish chiral environments facilitated the achievement of near-infrared *** findings offer a novel and practical strategy for achieving long-wavelength and long-lifetime CPL fluorescence without complex molecular engineering,presenting potential applications in various technological fields.

关键词： Room temperature phosphorescence Circularly polarized luminescence Forster resonance energy transfer

来源：评论

学校读者我要写书评

暂无评论

Probing the interlayer mechanical coupling of 2D layered materials-A review

引用

Progress in Natural science:materials International 2022年第5期32卷 528-537页

作者： Yinghui Sun Yufei Sun Rongming Wang Kai Liu Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science School of Mathematics and Physics University of Science and Technology Beijing State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Key Laboratory of Advanced Materials of Ministry of Education School of Materials Science and Engineering Tsinghua University

Two-dimensional(2D) layered materials are assembled through the intralayer covalent bonds and interlayer van der Waals(vdWs) interactions. The relatively weak interlayer vdWs interactions result in the weak interlayer mechanical coupling between layers, which strongly impacts the overall mechanical properties of multilayer 2D materials or heterostructures. Experimentally probing the interlayer mechanical coupling is of vital importance on the accumulation of fundamental parameters for their applications in flexible and stretchable devices, yet there are hardly comprehensive reviews in this research field. In this review, we firstly introduce the probing methods of interlayer mechanical coupling, including high-frequency and ultralow-frequency Raman characterizations,nanoindentation of multilayer 2D materials or heterostructures, surface indentation, pressurized blister test,characterization of spontaneously formed nanoblisters, and nano-friction tests. Based on the analysis and comparison of the existing methods and results, we also discuss the advantages and limitations of each ***, the challenges and opportunities in this promising field are discussed. This review summarizes the recent progress in the probing of interlayer mechanical coupling of 2D layered materials and will provide important reference for the rational design of flexible and stretchable devices.

关键词： van der Waals interaction Mechanical properties Indentation Heterostructures

来源：评论

学校读者我要写书评

暂无评论

Enhanced piezoelectric properties and thermal stability of LiNbO_(3)-modified PNN-PZT ceramics

引用

Journal of Materiomics 2024年第5期10卷 995-1003页

作者： Wei Peng Jianglei Chang Jianwei Zhao Dawei Wang Zhen Liu Genshui Wang Shuxiang Dong Institute for Advanced Study Shenzhen UniversityShenzhen518060China Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China School of Instrumentation Science and Engineering Harbin Institute of TechnologyHarbin150080China Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of SciencesShanghai201899China

Piezoelectric PZT ceramics with high piezoelectric properties and good thermal stability are urgently desired concerning the practical *** compositions of LiNbO_(3) modified Pb(Ni_(1/3)Nb_(2/3))O_(3)single bondPbZrO_(3)single bondPbTiO_(3) ceramics have been prepared in this *** effects of the introduction of the LiNbO_(3) on the system were comprehensively investigated in terms of the phase structure,microstructure,electric properties,and thermal stability behavior of the *** compositions are located in the morphotropic phase boundary(MPB)region,and the ratio of the rhombohedral(R)phase increases obviously with the increase of LiNbO_(3) *** increasing the LiNbO_(3) content,the piezoelectric properties were significantly *** sample added with 2%(in mole)LiNbO_(3) shows excellent electric properties,including T_(m)=185℃,εr=5,643,k_(p)=0.626,Q_(m)=51,d_(33)=902 pC/*** importantly,no thermal depolarization behavior was observed in the temperature range of 25–100℃.For PNN-PZT-x%LN ceramics,which is mainly attributed to the pinning effect resulted by the(Li_(Pb)-Nb_(Zr/Ti)) defect dipoles.

关键词： PNN-PZT LiNbO_(3) Piezoelectric property Defect dipole Thermal stability

来源：评论

学校读者我要写书评

暂无评论

Internal magnetic-field-enhanced photogenerated charge separation in ferromagnetic TiO_(2)surface heterojunctions

引用

Journal of materials science & technology 2023年第29期160卷 240-247页

作者： Guojing Wang Shirong Xiong Yonghui Chen Chunchang Wang Shasha Lv Ke Jia Yunjie Xiang Jianbo Liu Chong Liu Zhengcao Li School of Materials and Energy Lanzhou UniversityLanzhou 730000China State Key Laboratory of New Ceramics and Fine Processing Key Laboratory of Advanced Materials(MOE)School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Laboratory of Dielectric Functional Materials School of Physics and Material ScienceAnhui UniversityHefei 230601China Key Laboratory of Beam Technology Ministry of EducationCollege of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China School of Materials and Energy Southwest UniversityChongqing 404100China

The use of the internal magnetic field of ferromagnets can effectively promote charge separation and transfer(CST)in photoelectrochemical energy ***,photoelectrochemical materials with a ferromagnetic field are scarce,and the internal magnetic field is negligible in nonferromagnetic *** address this issue,we propose a rational method for preparing ferromagnetic TiO_(2)powder using controllable oxygen vacancies in anatase TiO_(2)with co-exposed{001}and{101}***,an ex-cellent saturation magnetisation of 0.0014 emu/g in TiO_(2)is achieved owing to an asymmetric and uneven charge *** with that of nonferromagnetic TiO_(2),the efficiency of photocatalytic hydro-gen generation of ferromagnetic TiO_(2)is improved by 0.64 *** enhancement of photocatalytic hy-drogen generation is due to the different forces exerted on the electrons and holes in the magnetic field,which significantly improve the photogenerated CST efficiency of ferromagnetic TiO_(2).This result high-lights the significant role of the synergistic regulation of the crystal structure and defects in regulating the ferromagnetic characteristics of *** findings of this study provide guidance for leveraging point defects to promote CST for high-efficiency solar-energy conversion systems.

关键词： Photocatalysis TiO_(2){001}-{101}surface heterojunctions Oxygen vacancies Ferromagnetic

来源：评论

学校读者我要写书评

暂无评论

Doping transition metal in PdSeO_(3)atomic layers by aqueous cation exchange:A new doping protocol for a new 2D photocatalyst

引用

Chinese Chemical Letters 2022年第8期33卷 3739-3744页

作者： Xiuming Zhang Rongrong Pan Tailei Hou Shuping Zhang Xiaodong Wan Yuemei Li Shan Liu Jia Liu Jiatao Zhang Beijing Key Laboratory of Construction-Tailorable Advanced Functional Materials and Green Applications Experimental Center of Advanced MaterialsSchool of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China

Elemental doping confined in atomically-thin 2 D semiconductors offers a compelling strategy for constructing high performance *** impressive progress has been achieved based on co-thermolysis method,the choices of dopants as well as semiconductor hosts are still quite limited to yield the elaborate photocatalyst with atomic-layer-confined doping defects,owing to the difficulty in balancing the reaction kinetics of different *** study shows that the cation exchange reaction,which is dictated by the Pearson's hard and soft acids and bases(HSAB)theory and allowed to proceed at mild temperatures,can be developed into a conceptually new protocol for engineering elemental doping confined in semiconductor atomic *** this aim,the two atomic layers of a new type of 2 D photocatalyst PdSe0_(3)(PdSe0_(3)2 ALs,1.1 nm)are created by liquid exfoliation and exploited as a proof-of-concept *** is demonstrated that the Mn(Ⅱ)dopants with controlled concentrations can be incorporated into PdSeO_(3)2 ALs via topological Mn^(2+) for-Pd^(2+) cation exchange performed in water/isopropanol solution at 30℃.The resulting Mn-doped PdSeO_(3)2 ALs present enhanced capacity for driving photocatalytic oxidation reactions in comparison with their undoped *** findings here suggest that the new route mediated by post synthetic cation exchange promises to give access to manifold 2 D confined-doping photocatalysts,with little perturbations on the thickness,morphology,and crystal structure of the atomically-thin semiconductor hosts.

关键词： 2D Semiconductor Atomic layers Photocatalysis Doping Cation exchange

来源：评论

学校读者我要写书评

暂无评论

Crystallography of precipitates in Mg alloys

引用

Journal of Magnesium and Alloys 2021年第2期9卷 416-431页

作者： Zhang-Zhi Shi Hong-Ting Chen Ke Zhang Fu-Zhi Dai Xue-Feng Liu Beijing Laboratory of Metallic Materials and Processing for Modern Transportation Key Laboratory for Advanced Materials Processing of Ministry of EducationSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China

Crystallography of precipitates in Mg alloys is indispensable to explain and predict alloy microstructures and *** order to obtain a global understanding of diversified experimental results,a general theory of singular interface is introduced,which provides the physical base and calculation methodology for interpreting precipitate morphology and orientation relationship(OR),especially useful for understanding irrational facets and *** by the theory,recent experimental findings are systematically summarized,including thermally stable and metastable precipitates with various crystal ***,theoretical advances inspired by the findings are introduced,which deepens our understanding on OR selection and preference of irrational *** last,future research directions in this field are proposed.

关键词： Mg alloys Precipitation Facet Orientation relationship

来源：评论

学校读者我要写书评

暂无评论

Design of Combined electromagnetic metamaterial absorber

Design of Combined electromagnetic metamaterial absorber

引用

2023 International Conference on Optoelectronic Information and functional materials, OIFM 2023

作者： Chen, Xu Sun, Yingjian Qi, Kainan Yuan, Xujin Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Institute of Advanced Structure Technology Beijing Institute of Technology Beijing100081 China Science and Technology on Electromagnetic Scattering Laboratory Beijing100854 China

ISBN: (纸本)9781510668119

The traditional resistive absorber, active absorber and other single structure absorbers or super surfaces have the disadvantages of narrow effective bandwidth and single adjustment mode. In order to solve this problem, a Combined structure of phase modulated active absorber and resistive absorber is proposed in this study to improve the broadband of scattering suppression and enrich the effect of adjustment methods, and its design method is described. Through reasonable optimization of the two components, the effects are overlapped and the camouflage effect is enhanced. The designed structure can achieve a scattering suppression effect of less than - 10dB at a bandwidth of 3.2GHz to 18GHz, where the phase modulation frequency band is greater than 4GHz. This structure has the same adjustment effect on TE and TM waves, and the adjustment effect is quite similar under the incidence of circularly polarized electromagnetic waves. The structure also has the structural advantage of low thickness, which is more suitable for practical applications. It has great application potential in electromagnetic compatibility, energy absorption, object camouflage. © 2023 SPIE.

关键词： Metamaterials

来源：评论

学校读者我要写书评

暂无评论

High entropy ultra-high temperature ceramic thermal insulator(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C with controlled microstructure and outstanding properties

引用

Journal of materials science & technology 2022年第24期119卷 190-199页

作者： Zhuojie Shao Zhen Wu Luchao Sun Xianpeng Liang Zhaoping Luo Haikun Chen Junning Li Jingyang Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China

Due to advancements of hypersonic vehicles,ultra-high temperature thermal insulation materials are urgently requested to shield harsh environment with superhigh heat *** this target,ultra-high temperature ceramics(UHTCs)are the only choice due to their excellent capability at ultra-high *** herein report a novel highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C fabricated by foam-gelcasting-freeze drying technology combined with in-situ pressureless reaction *** porous(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C exhibited ultra-high porosity of 86.4%-95.9%,as well as high strength and low thermal conductivity of 0.70–11.77 MPa and 0.164–0.239 W/(m·K),***,Si C sintering additive only locates at the pit of the surface of sintering neck between UHTC grains,and there is no secondary phase or intergranular film at the grain ***,the oxidation resistance of high entropy carbide powders is greatly improved compared with that of the mixed five carbide *** work clearly highlights the merits of highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C as an ultra-high temperature thermal insulation material.

关键词： High entropy UHTCs High porosity High strength Low thermal conductivity Oxidation resistance

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：