检索结果-南通市图书馆

Electronic origin of the unusual thermal properties of copper-based semiconductors:The s-d coupling-induced large phonon anharmonicity

引用

Science China(Physics,Mechanics & Astronomy) 2023年第7期66卷 112-119页

作者： Kaike Yang Huai Yang Yujia Sun Zhongming Wei Jun Zhang Ping-Heng Tan Jun-Wei Luo Shu-Shen Li Su-Huai Wei Hui-Xiong Deng State key laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China key laboratory of Low-Dimensional Quantum structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceSynergetic Innovation Center for Quantum Effects and ApplicationsDepartment of PhysicsHunan Normal UniversityChangsha 410081China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Computational Science Research Center Beijing 100193China

Copper(Cu)-based materials(such as cuprates,Cu chalcogenides,and Cu halides)often exhibit unusual properties such as superconductivity,ultralow thermal conductivity,and ***,the electronic origin of these unusual behaviors remains *** this study,we demonstrate that the high-lying occupied 3d orbital of Cu causes a strong s-d coupling with its unoccupied 4s state when local symmetry is *** leads to strong phonon anharmonicity and is responsible for these intriguing *** example,during thermal transport,symmetry-controlled s-d coupling can substantially lower the lattice potential barrier,thereby enhancing the anharmonicity and scattering between phonons and ultimately significantly reducing lattice thermal *** confirmed this understanding with Raman spectra measurements,which demonstrated a remarkable red shift in the phonon vibrational frequency with an increase in the temperature of Cu-based *** study shows that the cause of phonon anharmonicity is related to the fundamental electronic structures,which can also explain other unusual physical properties of the Cu compounds.

关键词： anharmonicity copper-based semiconductor electronic structure thermal conductivity

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

Synthesis,insecticidal and acaricidal activities of novel 2-arylpyrroles

引用

Science China Chemistry 2013年第1期56卷 117-123页

作者： LIU AiPing TANG Ming YU ShuYing LIU XingPing WANG XiaoGuang PEI Hui WU DaoXin HU Li OU XiaoMing HUANG MingZhi National engineering Research Center for Agrochemicals Hunan Research Institute of Chemical Industry hunan province key laboratory for Agrochemicals School of Chemistry and Biological engineering Changsha University of Science and Technology

To search for novel 2-arylpyrroles with unique biological activities,a series of novel 2-arylpyrrole derivatives were designed and synthesized,and their structures were characterized by 1 H and 13 C NMR spectroscopy,MS spectrometry,and elemental *** insecticidal activities against Lepidopteran pests (*** separata) and acaricidal activities against mites (*** urticae) were *** results of bioassays indicate that some of these title compounds exhibited excellent insecticidal and acaricidal *** example,4-bromo-1-((chloromethoxy)methyl)-2-(4-chloro phenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile (6a),4-bromo-2-(4-chlorophenyl)-1-((2-fluoroethoxy)-methyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile (6d) showed insecticidal activity against Mythimna separata and 4-bromo-2-(4-chlorophenyl)1-((isopropoxymethoxy)methyl)-5-(trifluoro methyl)pyrrole-3-carbonitrile (7d) showed acaricidal activity against Tetranychus *** were more effective than Chlorfenapyr,which has been the only commercialized member of a new class of chemicals of 2-arylpyrroles.

关键词： 2-arylpyrroles Chlorfenapyr synthesis insecticidal activity acaricidal activity

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

Effect of spatial configuration on adhesion of 1,2-disubstituted cyclohexane derivatives

引用

Chinese Chemical Letters 2023年第8期34卷 196-200页

作者： Qiao Zhang Yuhang Yin Jingfu Song Gai Zhao Shengyi Dong College of Chemistry and Chemical engineering Hunan UniversityChangsha 410082China State key laboratory of Mechanics and Control of Mechanical structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Spatial configuration has a significant effect on chemical ***,the importance of spatial configuration in supramolecular adhesive materials has been frequently *** this study,the effects of the spatial configuration on cohesion and adhesion were *** to the diversities of the chemical structures and assembly patterns,1,2-disubstituted cyclohexane derivatives were used in this combined experimental and theoretical *** self-sorting assembly of enantiopure isomers improved cohesion but had a negative effect on *** contrast,racemic mixtures displayed stronger adhesion ***,it was proven that the cis-configuration was more favorable for supramolecular adhesion than the *** addition,the influence of the spatial configuration of 1,2-disubstituted cyclohexane derivatives could be effectively mitigated by hydrogen bond donors or *** addition of natural acids yielded three-dimensional polymeric networks,in which the spatial configuration was not the decisive factor for supramolecular adhesion.

关键词： Spatial configuration Supramolecular adhesive material Assembly Cohesion Adhesion

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

Methane oxybromination over Rh-based catalysts:Effect of supports

引用

Chinese Journal of Chemical engineering 2020年第7期28卷 1809-1815页

作者： Peng Wang Lang Chen Sheng Shen Chak-Tong Au Shuangfeng Yin State key laboratory of Chemo/Biosensing and Chemometrics Hunan Provincial Key Laboratory for Cost-effective Utilization of Fossil Fuel Aimed at Reducing Carbon-dioxide EmissionsCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China College of Chemistry and Chemical engineering Hunan Institute of EngineeringXiangtan 411104China.

Bromine mediation has been regarded as one of the most efficient ways to activate and convert methane to useful *** article reports the effects of active components(Rh,Ru,Pd and Pt)and supports(SiO2,Mg O and Al2O3)on the catalysis of methane *** the prepared catalysts,Rh/SiO2 is the best in performance(CH4 conversion of ca.20%and CH3Br selectivity exceeding 70%).The results reveal that support type has a notable influence on the catalytic performance of Rh,especially on product *** high selectivity to CH3 Br over Rh/SiO2 is attributed to its low propensity for CH3Br *** was found that Rh small in particle size shows high catalytic activity and CH3Br *** silicalite-1 zeolite suffers from a certain degree of structural damage due to the presence of high temperature steam,the use of silicalite-1 as support results in a performance comparable to that of Rh/SiO2.

关键词： Methane conversion Oxybromination Methyl bromide Rhodium catalyst

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

engineering G-quadruplex aptamer to modulate its binding specificity

引用

National Science Review 2021年第4期8卷 107-113页

作者： Long Li Shujuan Xu Xueyu Peng Yuzhuo Ji He Yan Cheng Cui Xiaowei Li Xiaoshu Pan Lu Yang Liping Qiu Jianhui Jiang Weihong Tan Department of Chemistry and Department of Physiology and Functional Genomics Center for Research at the Bio/Nano Interface Health Cancer Center UF Genetics InstituteMcKnight Brain Institute University of Florida Molecular Science and Biomedicine laboratory State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan ProvinceHunan University Molecular Science and Biomedicine laboratory(MBL) State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical Engineering College of Biology Aptamer Engineering Center of Hunan ProvinceHunan University Institute of Molecular Medicine(IMM) Renji HospitalShanghai Jiao Tong University School of Medicine and College of Chemistry and Chemical EngineeringShanghai Jiao Tong University

The use of aptamers in bioanalytical and biomedical applications exploits their ability to recognize cell surface protein receptors. Targeted therapeutics and theranostics come to mind in this regard. However,protein receptors occur on both cancer and normal cells; as such, aptamers are now taxed with identifying high vs. low levels of protein expression. Inspired by the flexible template mechanism and elegant control of natural nucleic acid-based structures, we report an allosteric regulation strategy for constructing a structure-switching aptamer for enhanced target cell recognition by engineering aptamers with DNA intercalated motifs(i-motifs) responsive to the microenvironment, such as p H. Structure-switching sensitivity can be readily tuned by manipulating i-motif sequences. However, structure-switching sensitivity is difficult to estimate, making it equally difficult to effectively screen modified aptamers with the desired sensitivity. To address this problem, we selected a fluorescent probe capable of detecting G-quadruplex in complicated biological media.

关键词： G-quadruplex aptamer i-motif binding specificity cell microenvironment

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

Large eddy simulation study of 3D wind field in a complex mountainous area under different boundary conditions

引用

Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第7期25卷 541-556页

作者： Yan LI Lei YAN Xuhui HE School of Civil engineering Central South UniversityChangsha410075China National engineering Research Center for High-speed Railway Construction Changsha410075China hunan Provincial key laboratory for Disaster Prevention and Mitigation of Rail Transit engineering structures Changsha410075China

Large eddy simulations generally are used to predict 3D wind field characteristics in complex mountainous *** simulation boundary conditions,such as the height and length of the computational domain or the characteristics of inflow turbulence,can significantly impact the quality of *** this study,we examined these boundary conditions within the context of the mountainous terrain around a long-span cable-stayed bridge using a wind tunnel *** sizes of computational domains and turbulent incoming wind velocities were used in large eddy *** results show that when the height of the computational domain is five times greater than the height of the terrain model,there is minimal influence from the top wall on the wind field characteristics in this complex mountainous *** the length of the wake region of the computational domain has negligible effects on the wind *** in the inlet boundary reduces the length of the wake region on a leeward hill with a low slope,but has less impact on the mean wind velocity of steep hills.

关键词： Large eddy simulation(LES) Spectral representation method Recycling method High mountainous canyon Wind characteristics Atmospheric boundary layer Computational domain

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

Syntheses and structures of Three Hybrid Materials Using Vanadium Polyoxoanions and Macrocyclic Copper Complex as Building Blocks

引用

Chinese Journal of Structural Chemistry 2017年第1期36卷 135-142页

作者：欧光川廖阳向岳峰袁先友李治章 key laboratory of Comprehensive Utilization of Advantage Plants Resources in hunan South/Department of Biology and Chemistry Hunan University of Science and Engineering

The reactions of the four-coordinated macrocyclic copper complex [CuL]（ClO4）2（L = 1,4,8,11-tetraazacyclotetradecane） with NH4VO3 under different conditions gave three inorganic-organic hybrid materials of [CuL][VO3]2·2.33H2O（1）, [CuL]3[V（10）O（28）]·8H2O（2） and [Cu L]3[V6O（18）]·8H2O（3）. Single-crystal X-ray diffraction analyses reveal that three diverse vanadium polyoxoanions, [V6O（18）]6- ring, [V（10）O（28）]6- cluster, and [V（12）O（35）]^10- ring, were isolated from the same reactant NH4VO3 under different conditions. The [CuL]^2＋ bridges the [V10O28]6- clusters to form a two-dimensional sheet in 2, and link the [V6O（18）]^6- rings in 1 and [V（12）O（35）]^10- rings in 3 into three-dimensional frameworks, respectively.

关键词： polyoxovanadate macrocyclic copper(Ⅱ) complexes hybrid 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

A new failure mechanism for deep cavity and upper bound solution of supporting pressure

引用

Journal of Central South University 2017年第9期24卷 2082-2091页

作者：张道兵刘智振张佳华 hunan Provincial key laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and Technology School of Civil engineering Central South University

The investigation of supporting pressure is of great significance to the design of underground *** on the kinematical approach of limit analysis,an improved failure mechanism is proposed,and the supporting pressure is investigated for deep buried *** failure mechanisms are first introduced according to the existing failure mechanisms of geotechnical structures of limit analysis.A comparison with respect to the optimal failure mechanisms and the upper bound solutions provided among these three mechanisms are then conducted in an attempt to obtain the improved failure *** results provided by the improved failure mechanism are in good agreement with those by the existing method,the numerical solution and field monitoring,which demonstrates that the proposed failure mechanism is effective for the upper bound analysis of supporting pressure.

关键词： deep cavity failure mechanism limit analysis upper bound solution

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

Experimental research on the mechanism of non-monotonic characteristic between curing temperature and mechanical behaviors of Kevlar/epoxy composite

引用

Science China(Technological Sciences) 2018年第7期61卷 1012-1020页

作者： LIU Li HU DeAn ZHANG YouMin HAN Xu State key laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University key laboratory of Advanced Design and Simulation Technology for Special Equipments Ministry of Education Hunan University School of Mechanical engineering Hebei University of Technology

An experimental procedure is conducted to investigate the mechanism of the non-monotonic characteristic between curing temperature and mechanical behaviors of the Kevlar/epoxy composite in macro and micro levels. Different specimens are fabricated at four different curing temperatures and tested with ±45° off-axis tensile loading on a universal test machine coupled with digital image correlation(DIC). Moreover, the environmental scanning electron microscope(SEM) was used to obtain the micrographs and reveal their mechanism. The tested results show that the tensile mechanical behaviors are sensitive to the curing temperature and the relationship is non-monotonic. Also, as the temperature increases, the thicknesses of the specimens are significantly enlarged. By analyzing the SEM micrographs of the matrix grooves in the damage zone and DIC strain contours, it is concluded that the non-monotonic relationship is dominated by the properties of the Kevlar/epoxy interfaces and deformation of the distorted fibers.

关键词： Kevlar/epoxy composite mechanical behavior digital image correlation SEM micrograph non-monotonic character-istic distorted fiber

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

Hot hole multiplication from silver plasmon-resonated gold interband transitions for enhanced photoelectrochemical sensing

引用

Chinese Chemical Letters 2023年第12期34卷 522-526页

作者： Pei Zhang Bo Shen Xu Li Zhou Nie Kun Li State key laboratory of Chemo/Biosensing and Chemometrics Hunan Provincial Key Laboratory of Biomacromolecular Chemical BiologyCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

Compared with the widespread exploitation of hot electrons in plasmonic nanoparticles(NPs),hot holes generated from plasmonic metal interband transitions,are often overlooked in photoelectrochemistry,including photoelectrochemical *** by the subtle spectral overlap between the characteristic plasmonic bands of Ag NPs and interband transitions of Au,herein,we construct unusual core-shell Ag@Au NPs via an anti-galvanic reaction to promote the generation of hot *** from the unique plasmon resonances of Ag cores in specific wavelength regimes,Ag@Au can excite multiplied hot holes while Au cannot under the same *** satisfactory accuracy and good practicability,the photoelectrochemical sensing platform based on Ag@Au NPs possesses a detection limit of 77 nmol/L for glucose,exhibiting significantly higher sensitivity compared to that using Au *** work exemplifies the applications of interband hot-hole accumulation initiated by plasmons and may inspire more strategies to explore the utilization of hot holes in photoelectrochemistry.

关键词： Nanoplasmonics Core-shell structures Interband transition Hot hole Photoelectrochemical Biosensors

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

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：