检索结果-南通市图书馆

Fluorescent Quantum Yield of Pyrene Probe in Ultrathin Polymer Films

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

Chinese Journal of Polymer Science 2017年第3期35卷 400-406页

作者： Wan-chu Wei Shuo Feng cai-xia Zheng guo-dong Liang 祝方明 Guangdong Provincial Key Laboratory for High Performance Polymeric Composites School of Chemistry and Chemical EngineeringSun Yat-Sen University Key Laboratory for Polymer Composite and Functional Materials of Ministry of Education School of Chemistry and Chemical EngineeringSun Yat-Sen University

The fluorescently labelled polymers including pyrene-labelled polystyrene(PyPS) and pyrene-labelled poly(methyl methacrylate)(PyPMMA) with narrow molecular weight distributions were synthesized by the atom transfer radical copolymerization(ATRCP) of styrene or methyl methacrylate with 1-pyrenemethyl methacrylate(PyMMA). The ultrathin PyPS and PyPMMA films with the thickness ranging from 30 nm to 400 nm supported on the quartz slides were prepared by spin-coating. The fluorescent quantum yield(QY) of the pyrene probe in the ultrathin polymer films was investigated by the photoluminescence spectrometer using an integrating sphere detector. The QY decreased with the reduction of film thickness in the sub-200 nm range.

关键词： Pyrene-labelled polystyrene Pyrene-labelled poly(methyl methacrylate) Ultrathin polymer films Fluorescent quantum yield

Solidification Structure Refining of 430 Ferrite Stainless Steel With TiN Nucleation

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2008年第3期15卷 57-60页

作者： SHI cai-xia CHENG guo-guang LI Zhan-jun ZHAO Pei University of Science and Technology Beijing Beijing 100083 China Central Iron and Steel Research Institute Beijing 100081 China

The thermodynamics of TiN precipitation in liquid steel of 430 ferrite stainless steel has been calculated to find out the condition of TiN precipitation during the initial solidification stage. The difference in the solidification structure of 430 ferrite stainless steel has been discussed through comparative tests of vacuum induction furnace melting with different contents of Ti. It has been found that the equiaxed grain proportion can be increased from 20% to 69% as the content of Ti from 0.1% up to 0. 4%. The size of the TiN particles precipitated is 1-3 μm and the number of TiN particles is about （200- 300）/μm^2. It is found that the effect of using TiN to refine the solidification structure has been confirmed under the strict process condition used for 430 ferrite stainless steel.

关键词： titanium nitride (TIN) solidification thermodynamics 430 ferrite stainless steel

TICKET attracts pollen tubes and mediates reproductive isolation between relative species in Brassicaceae

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2019年第11期62卷 1413-1419页

作者： Jiang-guo Meng Meng-xia Zhang Wei-cai Yang Hong-Ju Li State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Collage of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China

In flowering plants,pollen tubes are attracted to the ovule by secreted peptides to release the sperm cells for double *** process is species-specific and acts as an important stage of reproductive isolation between *** we identified a cysteine-rich peptide TICKET2 in Arabidopsis thaliana and its orthologs in Arabidopsis lyrata and Capsella rebella that can attract the conspecific pollen tubes,but not the pollen tubes of relative species in *** knockout of the AtTICKET subclade compromised the pollen tube attraction *** study identified a new pollen tube attracting signal and shed light on the molecular basis of reproductive isolation.

关键词： pollen tube attraction peptide attractant reproductive isolation

Surface adsorption and diffusion of N on γ-Fe-Al (111) using first principles calculations

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2019年第8期26卷 882-887页

作者： Wen-shu Zhang cai-li Zhang Nan Dong Jian-guo Li Pei-de Han Zhu-xia Zhang Li-xia Ling College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China Key Laboratory of Interface Science and Engineering in Advanced Materials (Taiyuan University of Technology) Ministry of Education Taiyuan 030024 Shanxi China College of Chemistry and Chemical Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China

The adsorption and diffusion of N on γ-Fe-Al (111) surface have been investigated using the first principle calculations combined with density functional theory to explore the formation mechanism of AlN in the oxidation process of austenitic stainless steel. The results indicate that the most preferential adsorption site of N on the surface of γ-Fe (111) is fcc-hollow site. In addition, the stable positions are located at fcc adsorption site on clean and Al-doped γ-Fe (111) surface adsorbed 4.76 at.% N. Compared with the pure Fe system,γ-Fe-Al (111) system reduces the energy difference of N from the surface to the bulk. The system is most stable for 9.09 at.% N adsorbed on the octahedral interstice of the 2nd and 3rd atom interlamination of γ-Fe-Al (111) surface. Thus, the doping of Al makes it easier to spread N on the surface of γ-Fe (111). The increase in N in the atmosphere also accelerates the diffusion. Moreover, according to the density of states analysis, the interaction between Al and N was enhanced when 9.09 at.% N was adsorbed on the surface of γ-Fe-Al (111).

关键词： Nitrogen Surface adsorption Diffusion Austenitic stainless steel Density functional theory

Layout design of a mixed-flow production line based on processing energy consumption and buffer configuration

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

Advances in Manufacturing 2021年第3期9卷 369-387页

作者： cai-xia Zhang Shu-Lin Dong Hong-Yan Chu guo-Zhi Ding Zhi-Feng Liu Shi-Yao guo Chong-Bin Yang Institute of Advanced Manufacturing and Intelligent Technology Beijing University of TechnologyBeijing100124People’s Republic of China Beijing Key Laboratory of Advanced Manufacturing Technology Beijing University of TechnologyBeijing100124People’s Republic of China Beijing Xinghang Electromechanical Equipment Co. Ltd.Beijing100074People’s Republic of China School of Mechanical Engineering and Automation Beihang UniversityBeijing100191People’s Republic of China

Green manufacturing is a growing trend,and an effective layout design method for production lines can reduce resource wastage in *** study focuses on existing problems such as low equipment utilization,long standby time,and low logistics efficiency in a mixed-flow parallel production *** reduce the energy consumption,a novel method considering an independent buffer configuration and idle energy consumption analysis is proposed for this production line’s layout design.A logistics intensity model and a machine tool availability model are established to investigate the influences of independent buffer area configuration on the logistics intensity and machine tool *** solve the coupling problem between machine tools in such production lines,a decoupling strategy for the relationship between machine tool processing rates is *** energy consumption model for the machine tools,based on an optimized configuration of independent buffers,is *** model can effectively reduce the idle energy consumption of the machine tools while designing the workshop ***,considering the problems encountered in workshop production,a comprehensive optimization model for the mixed-flow production line is *** verify the effectiveness of the mathematical model,it is applied to an aviation cabin production *** results indicate that it can effectively solve the layout problem of mixed-flow parallel production lines and reduce the idle energy consumption of machine tools during *** proposed buffer configuration and layout design method can serve as a theoretical and practical reference for the layout design of mixed-flow parallel production lines.

关键词： Layout design Energy consumption Mixed flow production line Independent buffer configuration

Interplay of nonreciprocity and nonlinearity on mean-field energy and dynamics of a Bose–Einstein condensate in a double-well potential

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

Frontiers of physics 2022年第4期17卷 163-172页

作者： Yi-Piao Wu guo-Qing Zhang cai-xia Zhang Jian Xu Dan-Wei Zhang Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials School of Physics and Telecommunication EngineeringSouth China Normal UniversityGuangzhou 510006China Guangdong–Hong Kong Joint Laboratory of Quantum Matter Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China College of Electronics and Information Engineering Guangdong Ocean UniversityZhanjiang 524088China

We investigate the mean-field energy spectrum and dynamics in a Bose–Einstein condensate in a double-well potential with non-Hermiticity from the nonreciprocal hopping,and show that the interplay of nonreciprocity and nonlinearity leads to exotic *** the two-mode and mean-field approximations,the nonreciprocal generalization of the nonlinear Schrödinger equation and Bloch equations of motion for this system are *** analyze the PT phase diagram and the dynamical stability of fixed *** reentrance of PT-symmetric phase and the reformation of stable fixed points with increasing the nonreciprocity parameter are ***,we uncover a linear selftrapping effect induced by the *** the nonlinear case,the self-trapping oscillation is enhanced by the nonreciprocity and then collapses in the PT-broken phase,and can finally be recovered in the reentrant PT-symmetric phase.

关键词： Bose–Einstein condensate non-Hermitian physics nonlinear dynamics parity–time symmetry

Development of Soil Crusts Under Simulated Rainfall and Crust Formation on a Loess Soil as Influenced by Polyacrylamide

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2012年第3期22卷 415-424页

作者： HU xia LIU Lian-You LI Shun-Jiang cai Qiang-guo LU Yan-Li guo Jin-Rui State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875(China) Academy of Disaster Reduction and Emergency Management Beijing Normal UniversityBeijing 100875(China) Institute of Plant Nutrition and Resources Beijing Academy of Agriculture and Forestry SciencesBeijing 100097(China) Institute of Geographical Science and Natural Resources Research Chinese Academy of SciencesBeijing 100101(China)

This study evaluated the morphological characteristics and dynamic variation in characteristics of soil crust and iden-tified the relationships between soil crust and splash erosion under simulated *** effect of polyacrylamide (PAM) on soil aggregate stabilization and crust formation was also investigated.A laboratory rainfall simulation experiment was carried out using soil sample *** slices were examined under a polarized light microscopy and a scanning electron microscope (SEM).The results revealed that the soil crusts were thin and were characterized by a greater density,higher shear strength,finer porosity,and lower saturated hydraulic conductivity than the underlying *** types of crusts,i.e.,structural and depositional crusts,were *** texture was determined to be the most important soil variable influ-encing surface crust formation;depositional crust formation was primarily related to the skeleton characteristics of the soil and happened when the soil contained a high level of medium and large *** crust formation processes observed were as follows:1) The fine particles on the soil surface became spattered,leached,and then rough in response to raindrop impact and 2) the fine particles were washed into the subsoil pores while a compact dense layer concurrently formed at soil surface due to the continual compaction by the ***,the factors that influenced structural crust formation were a large amount of fine particles in the soil surface,continual impact of raindrops,dispersion of aggregates into fine particles,and the formation of a compact dense layer concurrently at the soil *** was concluded that the most important factor in the formation of soil crusts was raindrop *** polyacrylamide (PAM) was applied,it restored the soil structure and greatly increased soil aggregate *** effectively prevented crust ***,this function of PAM was not continuously effective and

关键词： depositional crust raindrop impact soil aggregates splash erosion structural crust

REFLECTION/TRANSMISSION CHARACTERISTICS OF A DISCONTINUOUS GALERKIN METHOD FOR MAXWELL'S EQUATIONS IN DISPERSIVE INHOMOGENEOUS MEDIA

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2008年第3期26卷 347-364页

作者： xia Ji Wei cai Pingwen Zhang Department of Mathematics and Statistics University of North Carolina at Charlotte USA Department of Scientific and Engineering Computing Peking University Beijing China

In this paper, we analyze the transmission and reflection properties of a high order discontinuous Galerkin method for dispersive Maxwell＇s equations, originally proposed by Lu et al. [J. Comput. Phys. 200 （2004）, pp. 549-580]. We study the reflection and transmission properties of the numerical method for up to second-order polynomial elements for one- and two-dimensional Maxwell＇s equations with rectangular meshes. High order accuracy has been shown for reflection and transmission coefficients near material interfaces.

关键词： Discontinuous Galerkin Method Reflection Transmission

Surface adhesive properties of continuous PBO fiber after air-plasma-grafting-epoxy treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第9期23卷 2165-2172页

作者： JIA cai-xia Liaoning Key Laboratory of Advanced Polymer Matrix Composites Manufacturing Technology Shenyang Aerospace University Shenyang 110136 China State Key Laboratory of Fine Chemicals & School of Chemical Engineering (Dalian University of Technology) Dalian 116024 China

It was found that air dielectric barrier discharge(DBD) plasma contributed to the grafting of epoxy resin onto continuous PBO fiber surface. This air-plasma-grafting-epoxy method yielded a noticeable enhancement in the interfacial adhesion between PBO fiber and thermoplastic matrix resin, with the interlaminar shear strength of the resulting composites increased by 66.7%. DSC and FTIR analyses were then used to study the curing behavior of epoxy coating on PBO fiber surface, deduce the possible grafting reactions and investigate the grafting mechanism. More importantly, TGA measurement showed that the grafting of epoxy onto PBO fiber had almost no effect on the composite heat resistance, and there was more thermoplastic matrix resin adhering to the fiber surface; the latter could also be clearly found in the SEM photos. Thereby, the air-plasma-grafting-epoxy treatment was proved to be an effective method for the improvement of continuous PBO fiber surface adhesive properties.

关键词： plasma grafting continuous PBO fiber surface adhesive properties heat resistance