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1.
Ali. Elamin. M. Saeed 《Annals of Differential Equations》2006,22(2):127-133
The purpose of this paper is to study a general Lienard type cubic system with one antisaddle and two saddles. We give some results of the existence and uniqueness of limit cycles as well as the evolution of limit cycles around the antisaddle for system (2) in the following when parameter a1 changes. 相似文献
2.
Fry BG Wüster W Ryan Ramjan SF Jackson T Martelli P Kini RM 《Rapid communications in mass spectrometry : RCM》2003,17(18):2047-2062
The evolution of the venomous function of snakes and the diversification of the toxins has been of tremendous research interest and considerable debate. It has become recently evident that the evolution of the toxins in the advanced snakes (Colubroidea) predated the evolution of the advanced, front-fanged delivery mechanisms. Historically, the venoms of snakes lacking front-fanged venom-delivery systems (conventionally grouped into the paraphyletic family Colubridae) have been largely neglected. In this study we used liquid chromatography with mass spectrometry (LC/MS) to analyze a large number of venoms from a wide array of species representing the major advanced snake clades Atractaspididae, Colubrinae, Elapidae, Homalopsinae, Natricinae, Psammophiinae, Pseudoxyrhophiinae, Xenodontinae, and Viperidae. We also present the first sequences of toxins from Azemiops feae as well as additional toxin sequences from the Colubrinae. The large body of data on molecular masses and retention times thus assembled demonstrates a hitherto unsuspected diversity of toxins in all lineages, having implications ranging from clinical management of envenomings to venom evolution to the use of isolated toxins as leads for drug design and development. Although definitive assignment of a toxin to a protein family can only be done through demonstrated structural studies such as N-terminal sequencing, the molecular mass data complemented by LC retention information, presented here, do permit formulation of reasonable hypotheses concerning snake venom evolution and potential clinical effects to a degree not possible till now, and some hypotheses of this kind are proposed here. The data will also be useful in biodiscovery. 相似文献
3.
Formation of homogeneous nanocomposite films at ambient temperature via miniemulsion polymerization using graphene oxide as surfactant 下载免费PDF全文
Yasemin Fadil S. H. C. Man Florent Jasinski Hideto Minami Stuart C. Thickett Per B. Zetterlund 《Journal of polymer science. Part A, Polymer chemistry》2017,55(14):2289-2297
A convenient and industrially scalable method for synthesis of homogeneous nanocomposite films comprising poly(styrene‐stat‐butyl acrylate) and nanodimensional graphene oxide (GO) or reduced GO (rGO) is presented. Importantly, the nanocomposite latex undergoes film formation at ambient temperature, thus alleviating any need for high temperature or high pressure methods such as compression molding. The method entails synthesis of an aqueous nanocomposite latex via miniemulsion copolymerization relying on nanodimensional GO sheets as sole surfactant, followed by ambient temperature film formation resulting in homogeneous film. For comparison, a similar latex obtained by physical mixing of a polymer latex with an aqueous GO dispersion results in severe phase separation, illustrating that the miniemulsion approach using GO as surfactant is key to obtaining homogeneous nanocomposite films. Finally, it is demonstrated that the GO sheets can be readily reduced to rGO in situ by heat treatment of the film. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2289–2297 相似文献
4.
Shirai T Ikegami M Fujimoto S Souda H Tanabe M Tongu H Noda A Noda K Fujimoto T Iwata S Shibuya S Smirnov A Meshkov I Fadil H Grieser M 《Physical review letters》2007,98(20):204801
The ordering of protons has been observed at a new storage ring, S-LSR, at Kyoto University. Abrupt jumps in the momentum spread and the Schottky noise power were observed for protons for the first time at a particle number of approximately 2000, upon applying electron cooling with electron currents of 25, 50, and 100 mA. The transition temperature was 0.17 and 1 meV in the longitudinal and transverse directions, respectively. The transverse temperature of the proton beam was much below that of electrons at the transition, which played an essential role in the ordering of protons. 相似文献
5.
Czechoslovak Mathematical Journal - Let K be a number field defined by an irreducible polynomial F(X) ∈ ?[X] and ?K its ring of integers. For every prime integer p, we give... 相似文献
6.
A method is described for the determination of 10–100 nmole of methanal and 20–150 nmole of ethanal and propanal. The method is based on the oxidation of aldehydes to the corresponding acids by mercuric ion which in turn is reduced to elemental mercury, followed by cold-vapour atomic absorption spectrometry. Calibration plots were constructed between the concentration of each aldehyde and absorbance, while the calibration from the conventional cold vapour procedure was used for total aldehydes determination. The method is selective and can be used for aldehyde determination in the presence of ketones, acetals, alcohols, acids, esters, ethers, organic chlorides and epoxides. This simple method is characterised by 98–102% recoveries and standard deviations of 3%. 相似文献
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Fadil Iyikanat Prof. Dr. Ramazan T. Senger Prof. Dr. Francois M. Peeters Prof. Dr. Hasan Sahin 《Chemphyschem》2016,17(23):3985-3991
By using density functional theory and non‐equilibrium Green′s function‐based methods, we investigated the electronic and transport properties of a TiS3 monolayer p–n junction. We constructed a lateral p–n junction on a TiS3 monolayer using Li and F adatoms. An applied bias voltage caused significant variability in the electronic and transport properties of the TiS3 p–n junction. In addition, the spin‐dependent current–voltage characteristics of the constructed TiS3 p–n junction were analyzed. Important device characteristics were found, such as negative differential resistance and rectifying diode behaviors for spin‐polarized currents in the TiS3 p–n junction. These prominent conduction properties of the TiS3 p–n junction offer remarkable opportunities for the design of nanoelectronic devices based on a recently synthesized single‐layered material. 相似文献
9.
Siberian Mathematical Journal - Let $ (K,\nu) $ be an arbitrary-rank valued field, let $ R_{\nu} $ be the valuation ring of $ (K,\nu) $ , and let $ K(\alpha)/K $ be... 相似文献
10.
Mandi J. Curtis Julia Beaumont Fadil Elamin Andrew S. Wilson Hannah E. C. Koon 《Rapid communications in mass spectrometry : RCM》2022,36(13):e9305