检索结果-南通市图书馆

Developments and challenges ahead in blue perovskite light-emitting devices

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第8期31卷 418-433,I0011页

作者： Lin Zhang run Long College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100875China

Recently,perovskite light-emitting diodes(Pe LEDs)have developed rapidly in the green,red,and nearinfrared light emissions,owing to the unique optoelectronic characteristics of halide perovskites,such as high carrier mobility,narrow emission linewidths,high photoluminescence quantum yield,as well as bandgap ***,the efficiency improvement in blue(especially deep-blue)Pe LEDs is still inferior to other analogs,which severely restricts the Pe LED ***,we systematically summarize the substantial progress in the performance of blue Pe LEDs based on different blue perovskite candidates,and recent advances from three aspects(i.e.,the sky-blue,pure-blue,and deep-blue light emissions).Then,we point out several challenges existing in deep-blue Pe LEDs,such as the effect of Cl-ions incorporation,spectral instability,ion migration,and the difficulty of charge injection,and highlight the strategies to improve device efficiency,to motivate further research and development of blue Pe LEDs.

关键词： Perovskite Blue emission Light-emitting diodes Stability Efficiency

Protein retention in dextran-grafted cation exchange chromatography:The influence of pHs,counterions and polymer structure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第7期28卷 1904-1910页

作者： run Liu Qinghong Shi Department of Biochemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Key Laboratory of Systems Bioengineering Ministry of EducationTianjin UniversityTianjin 300072China

Polymer-grafted ion exchange adsorbents were of great interest for the development of high-performance protein chromatography in biopharmaceutical and related *** this work,protein retention was systematically investigated in ion exchange chromatography packed respectively with dextran-grafted cation exchange adsorbents containing sulphopropyl(SP)ligand,SP Sepharose XL and Capto S,and non-grafted cation exchange adsorbent,SP Sepharose FF,using five *** an increase of buffer p Hs,retention factors of proteins decreased among all the adsorbents,demonstrating the dominant role of electrostatic interaction for protein binding on cation exchange *** evidences further revealed that the scattered positive charges on the surface of protein molecules,rather than net charge of protein molecule,determined protein retention on cation exchange ***,counterions including NH4^+,K^+,Na^+and Mg^2+exhibited distinct influence on protein *** was well ascribed to solvent-mediated indirect ion-macromolecule interactions and direct ion-macromolecule *** with SP Sepharose FF,polymer structure in dextran-grafted cation exchange adsorbents ultimately brought about different ligand distributions and smaller pore sizes,thereby regulating protein retention in cation exchange *** comparing the retention of myoglobin andβ-lactoglobulin B in SP Sepharose XL and Capto S,we reasonably speculated that the enhancement of nonelectrostatic interaction caused by reducing the space arm length was a major reason for an increasing retention factor of myoglobin in Capto *** results in this research help us understand adsorption mechanism of protein in polymer-grafted adsorbents and give scientific guidance for the development of chromatographic materials.

关键词： Protein retention Linear gradient elution Dextran-grafted cation exchange adsorbents Counterion pH

在线全文

学校读者我要写书评

暂无评论

非静水压作用下石膏电学性质的理论研究

原子与分子物理学报 2025年第6期42卷 129-135页

作者：周梅吴雷罗小松何宗润贵州民族大学物理与机电工程学院贵阳550025 重庆大学能源与动力工程学院重庆400044

地球内部广泛存在着差应力,这些外在因素的存在影响着矿物的性质,而矿物的电学性质与结构相变息息相关.为了更加了解地球内部结构与动力学过程,采用第一性原理方法,在等效平衡压0~10 GPa范围内计算地球内部浅层矿物石膏在静水压和非静... 详细信息

地球内部广泛存在着差应力,这些外在因素的存在影响着矿物的性质,而矿物的电学性质与结构相变息息相关.为了更加了解地球内部结构与动力学过程,采用第一性原理方法,在等效平衡压0~10 GPa范围内计算地球内部浅层矿物石膏在静水压和非静水压条件下的电学性质.计算结果表明:静水压和非静水压条件下无水石膏的密度和带隙变化基本一致,但二水石膏的密度和带隙在非静水压为6 GPa附近发生突变,这可能是由于非静水压环境使晶体结构更容易发生畸变,更有利于水分子氢键网络的重新排列和CaSO_(4)层间结构的塌缩,因此非静水压下可能更加有利于二水石膏在高温高压下的脱水反应.这对理解地幔中矿物的脱水和储水产生重大的影响,为理解地幔中矿物的脱氢和储水提供理论依据.

关键词：差应力石膏电学性质第一性原理

维普期刊数据库博看期刊

Ageing in worms:N-acylethanolamines take control

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2011年第9期2卷 689-690页

作者： run Shen The Salk Institute for Biological Studies 10010 North Torrey Pines RoadLa JollaCA 92037USA

Studies of dietary restriction’s effect on lifespan extension in *** and other model organisms have greatly expanded our knowledge about genetic network underlying stress response,ageing,and ageing related *** key molecules and signaling pathways implicated are Foxo(daf-16)and Foxa(pha-4)transcriptional factors and the nutrient sensing insulin/TOR pathway(Wolkow et al.,2000;Panowski et al.,2007;Hansen et al.,2008).

关键词： stress Ageing expanded

Electrochemical urea production directly from N2 and CO2 in ambient aqueous media

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2020年第11期63卷 1580-1581页

作者： run Shi Tierui Zhang Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Chemical fertilizer industry is of great importance to agricultural ***(CO(NH2)2),which was firstly discovered by Hilaire Rouelle in 1773,is the most widely used chemical fertilizers in the world[1].Up to now,urea still represents the solid nitrogen fertilizer with the highest nitrogen *** synthesis of urea is therefore closely related to the fertilizer production and very important in the synthetic *** modern ammonia synthesis industry has laid a foundation for the large-scale artificial synthesis of ***,in this route,urea is typically synthesized from the Ostwald post-process of ammonia.

关键词： chemistry. ammonia typically

Community Characteristics of Early Recovery Vegetation on Abandoned Lands of Shifting Cultivation in Bawangling of Hainan Island, South China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2005年第5期47卷 530-538页

作者： YiDING run-GuoZANG KeyLaboratoryofForestEcologyandEnvironment theStateForestryAdministrationInstituteofForestEcologyEnvironmentandProtectiontheChineseAcademyofForestryBeijing100091China

: Shifting cultivation is a major form of agricultural practice in most parts of tropical regions worldwide. In places where the bush fallow period is excessively shortened or the period of cultivation is extended for too long, the rate of vegetation recovery and biodiversity on abandoned lands of shifting cultivation would decline. The recovery of the secondary plant communities could even be inhibited for a prolonged period because of grass occupancy. Because of the vital significance of the early recovery communities to secondary succession, we studied the community characteristics of early recovery vegetation on abandoned lands of shifting cultivation in Bawangling of Hainan Island. Measurements were made of the community composition and structure of early recovery vegetation. The sprouting abilities of different functional groups and different species in the same functional group, and the effect of the grass functional group on the composition and quantitative characteristics of tree and shrub functional groups were analyzed. Results indicated that only a few families, genera, or species apparently dominated in the early recovery vegetation on the abandoned lands of shifting cultivation and that deciduous species occurred with a rather high percentage in this early recovery community compared with the natural secondary or old growth forests. Small-sized individuals dominated the woody community. The abundance and basal area of sprouting stems for species in the tree functional group were greater than those of seeder stems, whereas the abundance and basal area of resprouters and seeders for species in the shrub functional group did not differ. The total abundance of stems for the community, stem abundances for species in tree or shrub functional groups, and for seeder or resprouter stems were all negatively correlated with coverage of the grass functional group. The mean sprouting ability in the tree functional group was greater than in the shrub functional grou

关键词： early recovery vegetation functional groups regeneration mode shifting cultivation sprouting ability tropical forest

Versatile platform of nonlocal metasurfaces for both spectral and spatial control of lightt waves

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

Light(Science & Applications) 2022年第11期11卷 2553-2555页

作者： run Chen Shuming Wang National Laboratory of Solid-State Microstructures School of PhysicsNanjing UniversityNanjing 210093China

Multifunctional nonlocal metasurfaces based on quasi-bound states in the continuum are experimentally demonstrated,which shapes the wavefronts at the resonant wavelengths while have no effect on other *** means of cascade and orthogonal perturbations,the nonlocal metasurface devices can be extended to a versatile platform with multifunction.

关键词： surfaces nonlocal versatile

Two-dimensional phonon engineering triggers microscale thermal functionalities

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

National Science Review 2019年第6期6卷 1071-1073页

作者： run Hu Xiaobing Luo State Key Laboratory of Coal Combustion School of Energy and Power Engineering Huazhong University of Science and Technology

Thermal metamaterials enable heat-flow manipulation alongside many emerg-ing thermal functionalities. However,macroscale experimental performancesare usually less satisfactory due to the errors of effective medium des... 详细信息

关键词： Two-dimensional phonon engineering triggers microscale thermal functionalities

Attractive Model and Marketing Implications of Theme Shopping Tourism Destination

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Geographical Science 2010年第6期20卷 562-567页

作者： LIU Jiaming WANG run Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Graduate University of the Chinese Academy of Sciences Beijing 100049China

This paper discusses the definition and connotation of Theme Shopping Tourism(TST) destination,and reveals the attractive distance of TST destination based on the utility function derived from the supposed demand *** attractive model is *** to this attractive model,it is can be known that the attractive distance is related to the price difference of the theme commodities between TST destination and tourist origin place,the average expenditure of transport,the demand elasticity of price,the actual price of sightseeing spot,the critical price that a tourist will afford,the number of nights that a tourist stays on the TST destination and the price level of accommodation in the TST *** change mechanism of attractive distance of TST destinations is revealed in this paper,and implications on TST marketing are put ***,theme commodities should be ***,lower price is the primary pulling factor of theme shopping ***,the route combining with sightseeing spots is beneficial to shopping *** last,TST development is one way of rejuvenating the falling destinations.

关键词： theme shopping tourism destination attractive model utility function tourism marketing