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Cu_2ZnSnS_4 thin films prepared by sulfurizing different multilayer metal precursors

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science china(Technological sciences) 2009年第1期52卷 269-272页

作者： ZHANG Jun & SHAO LeXi school of Physical science and Technology, Zhanjiang normal university, Zhanjiang 524048, china school of Physical science and Technology Zhanjiang Normal University Zhanjiang 524048 China

Cu2ZnSnS4 (CZTS) thin films were successfully fabricated on glass substrates by sulfurizing Cu-Sn-Zn multilayer precursors, which were deposited by ion beam sputtering and RF magnetron sputtering, respectively. The structural, electrical and optical properties of the prepared films under various processing conditions were investigated in detail. Results showed that the as-deposited CZTS thin films with the precursors by both ion beam sputtering and RF magnetron sputtering have a composition near stoichiometric. The crystallization of the samples, however, has a strong dependence on the atomic percent of constituents of the prepared CZTS films. A single phase stannite-type structure CZTS with a large absorption coefficient of 104/cm in the visible range could be obtained after sulfurization at 520℃ for 2 h. The samples relative to the RF magnetron sputtering showed a low resistivity of 0.073 ?cm and band gap energy of about 1.53 eV. The samples relative to the ion beam sputtering exhibited a resistivity of 0.36 Ωcm and the band gap energy is about 1.51 eV.

关键词： Cu_2ZnSnS_4 solar cell thin film ion beams sputtering RF sputtering

Optical pulse compression using a nonlinear optical loop mirror constructed from dispersion decreasing fiber

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science china(Technological sciences) 2004年第1期47卷 33-50页

作者： CAO Wenhua & LIU Songhaoschool of Information, Wuyi university, Jiangmen 529020, china school for Information and Optoelectronic science and Engineering, South china normal university, Guangzhou 510631, china 1. school of Information Wuyi University 529020 Jiangmen China 2. school for Information and Optoelectronic science and Engineering South China Normal University 510631 Guangzhou China

A novel scheme to compress optical pulses is proposed and demonstrated numerically, which is based on a nonlinear optical loop mirror constructed from dispersion decreasing fiber (DDF). We show that, in contrast to the conventional soliton-effect pulse compression in which compressed pulses are always accompanied by pedestals and frequency chirps owning to nonlinear effects, the proposed scheme can completely suppress pulse pedestals and frequency chirps. Unlike the adiabatic compression technique in which DDF length must increase exponentially with input pulsewidth, the proposed scheme does not require adiabatic condition and therefore can be used to compress long pulses by using reasonable fiber lengths. For input pulses with peak powers higher than a threshold value, the compressed pulses can propagate like fundamental solitons. Furthermore, the scheme is fairly insensitive to small variations in the loop length and is more robust to higher-order nonlinear effects and initial frequency chirps than the adiabatic compression technique.

关键词： dispersion decreasing fiber (DDF), optical pulse compression, optical solitons.

Finite p-Groups with a Cyclic Subgroup of Index p3

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Journal of Mathematical Research with Applications 2012年第5期32卷 505-529页

作者： Qinhai ZHANG,Pujin LI Department of Mathematics,shanxi normal university,shanxi 041004,P.R.china Department of Mathematics Shanxi Normal University Shanxi 041004

We classify up to isomorphism those finite p-groups,for odd primes p,which contain a cyclic subgroup of index p3.

关键词： finite p-groups inner abelian p-groups metacyclic p-groups regular p-groups irregular p-groups.

Universal approximation of polygonal fuzzy neural networks in sense of K-integral norms

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science china(Information sciences) 2011年第11期54卷 2307-2323页

作者： WANG GuiJun 1 & LI XiaoPing 2 1 school of Mathematics science,Tianjin normal university,Tianjin 300387,china 2 school of Management,Tianjin normal university,Tianjin 300387,china 1. school of Mathematics science Tianjin Normal University Tianjin 300387 China2. School of Management Tianjin Normal University Tianjin 300387 China

In this paper,we introduce polygonal fuzzy numbers to overcome the operational complexity of ordinary fuzzy numbers,and obtain two important inequalities by taking advantage of their fine *** presenting an actual example,we demonstrate that the approximation capability of polygonal fuzzy numbers is ***,the concepts of K-quasi-additive integrals and K-integral norms are *** the polygonal fuzzy numbers space satisfies separability,the density problems for several functions spaces can be studied,by means of fuzzy-valued simple functions and fuzzy-valued Bernstein *** establish that the class of the integrally-bounded fuzzy-valued functions spans a complete and separable metric space in the K-integral ***,in the sense of K-integral norms,the universal approximation of fourlayer regular polygonal fuzzy neural networks for fuzzy-valued simple functions is ***,we show that this type of networks also possesses universal approximation for the class of integrally-bounded fuzzyvalued *** result indicates that the approximation capability which regular polygonal fuzzy neural networks for continuous fuzzy systems can be extended as for general integrable systems.

关键词： polygonal fuzzy numbers K-quasi-additive integrals K-integral norms polygonal fuzzy neural networks universal approximations

On the Hero’s Tragedy in The Great Gatsby

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体育研究与教育 2011年第S1期26卷 142-143页

作者： WU Qiang-rong(Foreign Languages school,shanxi normal Uninersity,linfen,shanxi 041004,china)

The Great Gatsby is the representative work of *** Fitzgerald,the famous American novelist in the 20th *** a deep and concise tone,it tells readers a tragedy about the break of the American *** lived in the Jazz Age and pursued his dream persistently but finally *** his tragedy,we can discover the social root of his failure,the impetuousness of the Lost Generation and the disenchantment of the American Dream.

关键词： Gatsby tragedy the American Dream

Two new Jurassic stoneflies (Insecta: Plecoptera) from Daohugou, Inner Mongolia, china

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Progress in Natural science:Materials International 2008年第8期18卷 1039-1042页

作者： Yushuang Liu, Dong Ren * College of life science, Capital normal university, 105 Xisanhuanbeilu, Haidian District, Beijing 100037, china College of life science Capital Normal University 105 Xisanhuanbeilu Haidian District Beijing 100037 China

Two new genera and two new species of family Taeniopterygidae, Mengitaenioptera multiramis gen. et sp. nov. and Noviramonemoura trinervis gen. et sp. nov. are described. These fossils were collected from Daohugou Village (the Middle Jurassic), Inner Mongolia, china. Hitherto, these fossil species from Daohugou are the oldest taeniopterygids. Both simple and complex venations simultaneously occurred in this group, which reveals that the early diversification of taeniopterids was well underway by the Middle Jurassic. Therefore, we prefer to adopt the Comstock’s opinion that the venation of taeniopterids was derived from the simple venation of the older group (such as Palaeonemouridae) at much ancient geological time ago. Some of the descendants carried this simple venation; others evolved into complex venation with many additional crossveins and branches.

关键词： Plecoptera Taeniopterygidae Daohugou Inner Mongolia Middle Jurassic

Theorems for Testing Local Activity of CNN and Application to Cardiac Purkinje Equations

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 139-146页

作者： Lequan Min(Applied science school, university of science and Technology Beijing, Beijing 100083, china) Applied science school University of Science and Technology Beijing Beijing 100083 China

The theorems for testing the local in one-port cellular neural/inear network (CNN) cells with four local state variables are presented. Using the theorems computes the bifurcation diagrams of the cardiac Purkinje fiber (CPE) equations Which describethe long-lasting action and pace-maker potentials of the Purkinje fiber of the heart. The computer simulation shows that periodic trajectories or convergent trajectories of the CPF Equations can be foun if the cormsponing cell Parameters are located in a positive domainbut nearby edge of chaos. In particular a heart with approximate normal frequency of heartbeat but non-normal electrocardiogram maysuddenly stop by slightly perturbing the parameters of the corresponding CPF Equations when the Paramders are located nearby the edge of chaos in the bifurcation diagrams. This research seems to interpret reasonbly the phenomena that patients with cardiac diseases might suddenly die without warning.

关键词： cellular neural network local activity cardiac Purkinje fiber heartbeat

Phylogenetic relationship and morphological evolution in the subfamily Limenitidinae(Lepidoptera:Nymphalidae)

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Progress in Natural science:Materials International 2008年第11期18卷 1357-1364页

作者： Min Zhang~a Yang Zhong~b Tianwen Cao~c Yupeng Geng~b Yuan Zhang~b Ke Jin~b Zhumei Ren~a Rui Zhang~a Yaping Guo~a Enbo Ma~(a,*) a Research Institute of Applied Biology and College of life science and Technology,shanxi university,Taiyuan,shanxi 030006,china b school of life sciences,Fudan university Shanghai 200433,china c Institute of Plant Protection,shanxi Academy of Agricultural science,Taiyuan 030031,china Research Institute of Applied Biology and College of life science and Technology Shanxi University Taiyuan Shanxi 030006 China school of life sciences Fudan University Shanghai 200433 China Institute of Plant Protection Shanxi Academy of Agricultural Science Taiyuan 030031 China

The mitochondrial cytochrome oxidase subunit I(COI)gene and the nuclear elongation factor 1α(EF-1α)gene were sequenced from 29 species of Nymphalidae(Nymphalidae,Lepidoptera).Phylogenetic trees were constructed based on the sequences determined from the 29 species and sequences of other 36 species deposited in GenBank using the neighbor-joining(N J),maximum likelihood(ML)and Bayesian methods with Libythea celtis(Libytheinae)as the *** phylogenetic trees indicated four major *** A includes three subfamilies:Apaturinae,Nymphalinae,and Limenitidinae,excluding the tribe Limenitidini;Clade B includes the subfam- ilies Heliconiinae and the tribe Limenitidini;Clade C includes Satyrinae,Calinaginae,Charaxinae and Morphinae;and Clade D includes subfamily *** study suggested that the tribes Pseudergolini,Biblidini,Limenitidini and Cyrestidini should be considered as subfamilies and confirmed the interspecific relationships within the subfamily Pseudergolinae,namely Amnosia +(Pseudergolis +(Stibo- chiona + Dichorragia)).We then mapped three morphological characters(spot of anal angle,eyespots,and process from outer margin of hind wing)onto the phylogenetic tree constructed by ML analysis using the combined sequence *** on this the evolutionary patterns of these morphological characters were identifed,they indicated that the three characters evolved repeatedly in the family Nymphalidae.

关键词： Nymphalidae Limenitidinae Mitochondrial DNA cytochrome oxidase subunitⅠgene(COI) Nuclear elongation factor 1αgene(EF-1α) Molecular phylogeny Character evolution

New fossil caddisfly from Middle Jurassic of Daohugou,Inner Mongolia,china(Trichoptera:Philopotamidae)

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Progress in Natural science:Materials International 2009年第10期19卷 1427-1431页

作者： Meixia Wang,Yunyun Zhao,Dong Ren College of life science,Capital normal university,Beijing 100037,china [a]College of life science Capital Normal University Beijing 100037 China

A new genus and new species,Juraphilopotamus lubricus *** ***.,from the Middle Jurassic Jiulongshan Formation of Daohugou,Inner Mongolia,china,is described and *** may be the first record of the family Philopotamidae in china,extending the geographic distribution of this family.A detailed description and illustration of the specimen along with a brief review of the fossil Philopotamidae are given.A proposal on dispersionandmigration of Philopotamidae and problems of the paleoenvironment of the Daohugou beds are discussed.

关键词： Insecta Juraphilopotamus Philopotamidae Middle Jurassic Biogeography