检索结果-南通市图书馆

On Laguerre Form and Laguerre Isoparametric Hypersurfaces

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第3期31卷 501-510页

作者： jian bo FANG Department of Mathematics Tongji University School of Mathematics and Statistics Chuxiong Normal University

Let x ： M^n-1→ R^nbe an umbilical free hypersurface with non-zero principal curvatures.M is called Laguerre isoparametric if it satisfies two conditions, namely, it has vanishing Laguerre form and has constant Lauerre principal curvatures. In this paper, under the condition of having constant Laguerre principal curvatures, we show that the hypersurface is of vanishing Laguerre form if and only if its Laguerre form is parallel with respect to the Levi-Civita connection of its Laguerre metric.

关键词： Laguerre isoparametric hypersurface Laguerre second fundamental form Laguerre metric Laguerre form parallel Laguerre form

Spontaneous Magnetization and Magnon-TA Phonon Interaction during the Premartensitic Transformation in Ni2 MnGa Alloy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第10期29卷 163-166页

作者： wan jian-Feng School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240

The magnetic anomaly associated with the premartensitic transformation(PT)in Heusler alloy Ni_(2)MnGa is investigated by using the Green's function technique based on the magnon-TA phonon *** results of the numerical calculations suggest that the magnetic anomaly during the PT may originate from the strong magnon-TA phonon interaction,because this kind of coupling effect will destroy the magnetic ordering in some local zones and reduce the magnetization of the ***-magnon interaction plays a positive role in enhancing the magnetization and tends to reduce the PT temperature while this kind of interaction has little effect on the characteristic TA phonon-wavevector corresponding to the anomaly of spontaneous magnetization at the PT temperature.

关键词： martensitic alloy transformation

Removal of sulfonamide antibiotics from wastewater by gamma irradiation in presence of iron ions

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

Nuclear Science and Techniques 2016年第5期27卷 104-108页

作者： Zhong wan jian-Long wang Collaborative Innovation Center for Advanced Nuclear Energy Technology INET Tsinghua UniversityBeijing 100084 China Beijing Key Laboratory of Radioactive Waste Treatment INET Tsinghua University Beijing 100084 China

The presence of sulfonamide antibiotics in aquatic environments has received increasing attention in recent ***(SD),a widely used heterocyclic sulfonamide pharmaceutical,has entered into the receiving water *** this paper,gamma rays are used to irradiate samples of sulfadiazine antibiotics-containing *** results demonstrate that SD can be effectively degraded by irradiation,but the mineralization degree of SD(in terms of TOC) is not as efficient as the SD *** addition of Fe^(2+) can significantly enhance the SD degradation and mineralization through the generation of hydroxyl radical by catalytic decomposition of H_2O_2 from water *** chromatography analysis indicates that sulfate ions(SO_4^(2-)) and formate(HCOO^-) are the main intermediate *** irradiation is a promising technology for removing low-concentration antibiotics from water and wastewater.

关键词： γ射线照射废水样品抗生素磺胺类铁离子降解效率离子色谱分析羟基自由基

Thiazoloisoindigo-based Polymer Semiconductors: Synthesis,Structure-Property Relationship, Charge Carrier Polarity, and Field-Effect Transistor Performance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第1期42卷 24-31,I0006页

作者： bo-Wen Li Miao Xiong Mei-Hua Liu Zhi-Gao Li Long Sang Zi-Han Xiong Biao Xiao jian Pei Xiao-bo wan Key Laboratory of Optoelectronic Chemical Materials and Devices Ministry of EducationSchoolofOptoelectronic Materials&TechnologyJianghan UniversityWuhan430056China Bejing National Laboratoryfor Molecular Sciences the Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Developing new polymeric semiconductors with excellent device performance is essential for organic electronics. Herein, we synthesized two new thiazoloisoindigo(Tz II)-based polymers, namely, P(Tz II-d Th-d Th) and P(Tz II-d Th-d Tz), by copolymerizing thiophene-flanked Tz II with bithiophene and bithiazole, respectively. Owing to the more electron-deficient nature of bithiazole than bithiophene, P(Tz II-d Th-d Tz)possesses deeper LUMO/HOMO levels of-3.45/-5.47 e V than P(Tz II-d Th-d Th)(-3.34/-5.32 e V). The organic field-effect transistor(OFET) devices based on P(Tz II-d Th-d Th) exhibited p-type behaviors with an average hole mobility value as high as 1.43 cm^(2)·V^(-1)·s^(-1), while P(Tz II-d Th-d Tz)showed typical ambipolar characteristics with average hole and electron mobilities of 0.38 and 0.56 cm^(2)·V^(-1)·s^(-1). In addition, we compared the performances of both polymers with other Tz II-based polymers reported in our previous work, and showed that the charge carrier polarity can be manipulated by adjusting the number of the thiophene units between the acceptor unit. As the increase of the number of thiophene rings,charge carrier polarity shifts from electron-dominated ambipolar transport to hole-dominated ambipolar transport and then to unipolar hole transport in OFETs, which provides an effective molecular design strategy for further optimization of polymer OFET performance.

关键词： Field-effect transistor Charge carrier polarity Thiazoloisoindigo

AIEgens-lightened Functional Polymers: Synthesis, Properties and Applications

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2019年第4期37卷 302-326,I0005页

作者： Shi-Yuan Zhou Hai-bo wan Feng Zhou Pei-Yang Gu Qing-Feng Xu jian-Mei Lu College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Suzhou Nano Science and TechnologySoochow University

Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices, etc. In this review, we summarize recent advances concerning AIE polymers. Four types of AIE polymers including end-functionalized polymers, side-chain polymers, main-chain polymers, and other polymers according to the location of AIEgens, are described. Their synthetic preparation, optical property, AIE effects, and applications are also illustrated in this review.

关键词： Aggregation-induced emission Functional polymers Synthetic method Application

Application of multi-resolution analysis in sonar image denoising

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2008年第6期19卷 1082-1089页

作者： Shang Zhengguo Zhao Chunhui wan jian Coll. of Information & Communication Engineering Harbin Engineering Univ. Harbin 150001 P. R. China

Sonar images have complex background, low contrast, and deteriorative edges; these characteristics make it difficult for researchers to dispose the sonar objects. The multi-resolution analysis represents the signals in different scales efficiently, which is widely used in image processing. Wavelets are successful in disposing point discontinuities in one dimension, but not in two dimensions. The finite Ridgelet transform （FRIT） deals efficiently with the singularity in high dimension. It presents three improved denoising approaches, which are based on FRIT and used in the sonar image disposal technique. By experiment and comparison with traditional methods, these approaches not only suppress the artifacts, but also obtain good effect in edge keeping and SNR of the sonar image denoising.

关键词： multi-resolution analysis wavelet transform ridgelet transform cycle sample adaptive denoisingenergy delamination

Vectorial optical fields： recent advances and future prospects

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2018年第1期63卷 54-74页

作者： jian Chen Chenhao wan Qiwen Zhan School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology Shanghai 200093 China Department of Electro-Optics and Photonics University of Dayton Dayton OH 45469 USA School of Electronic Engineering University of Electronic Science and Technology of China Chengdu 611731 China School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China

Driven by their potential applications, vectorial optical fields with spatially inhomogeneous states of polarization within the cross section have drawn significant attention recently. This work intends to review some of the latest development of this rapidly growing field of optics and offer a general overview of the current status of this field in a few areas. Mathematical descriptions of generalized vectorial optical fields are provided along with several special examples. A time-reversal methodology for the creation of a wide variety of exotic optical focal fields with prescribed characteristics within the focal volume is presented. Recently developed methods for the generation of vectorial optical fields that utilize fiber lasers,digital lasers, vectorial optical field generator, metasurfaces or photoalignment liquid crystals are summarized. The interactions of these vectorial optical fields with various micro-and nano-structures are presented and the prospects of their potential applications are discussed. The connection of vectorial optical fields with higher dimensionality in quantum information is summarized.

关键词： Vectorial optical field Cylindrical vector beam Full Poincaré beam Spatial light modulator Metasurface Spin-orbit interaction Quantum information Quantum communication

Electrochemical hydrogen storage properties of melt-spun Ti0.9Zr0.1V0.2Ni1.5La0.5 alloy

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2011年第2期6卷 209-213页

作者： jian wanG Guang-bo CHE Qing-wei wanG wan-xi ZHANG Li-min wanG Key Laboratory of Preparation and Applications of Environmental Friendly Materials （Ministry of Education） Jilin Normal University Siping 136000 China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

The Ti0.9Zr0.1V0.2Ni1.5La0.5 alloy samples were synthesized by melt-spinning technique at the different wheel velocity （cooling rate）, and the structure and electrochenfical hydrogen storage properties were investigated. The result indicated that the structure of the melt-spun ribbons mainly contains C14 Laves phase and V-based solid solution phase. The discharge capacity, cyclic stability, high-rate discharge ability and electrochemical kinetic of the alloy electrodes are correlated with the cooling rate （wheel velocity）, and the maximum discharge capacity is over 200 mA.h/g at the wheel velocity of 20 m/s.

关键词： Ti0.9Zr0.1V0.2Ni1.5La0.5 alloy melt-spinning hydrogen storage electrochemical prop-erties

A PROJECTION-TYPE METHOD FOR SOLVING VARIOUS WEBER PROBLEMS

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

Journal of Computational Mathematics 2006年第4期24卷 527-538页

作者： jian-lin jiang bo Chen Department of Mathematics Nanjing University Nanjing 210093 China

This paper investigates various Weber problems including unconstrained Weber problems and constrained Weber problems under l1, l2 and l∞-norms. First with a transformation technique various Weber problems are turned into a class of monotone linear variational inequalities. By exploiting the favorable structure of these variational inequalities, we present a new projection-type method for them. Compared with some other projection-type methods which can solve monotone linear variational inequality, this new projection-type method is simple in numerical implementations and more efficient for solving this class of problems; Compared with some popular methods for solving unconstrained Weber problem and constrained Weber problem, a singularity would not happen in this new method and it is more reliable by using this new method to solve various Weber problems.

关键词： Linear variational inequality Various Weber problems Projection-type method Slack technique.