EXISTENCE OF PERIODIC SOLUTION OF A NEURONIC EQUATION

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过渡金属大环配合物的研究Ⅲ 4-硝基-苯并15冠-5与钴(Ⅱ)、铜(Ⅱ)和银(Ⅰ)配合物的合成及性质

有关冠醚配体与碱金属,碱土金属和稀土离子形成配合物的特性研究,国内外均有报导,但冠醚与d-过渡金属离子配合物的研究工作,则开展较晚,文献报导亦甚少。本文为探讨4-硝基-苯并15冠-5(No_2·B15C15)与过渡金属离子的配位能力,合成了Co(Ⅱ),Cu(Ⅱ),和Ag(Ⅰ)与4-硝基-苯并15冠-5配合物。并进行了元素分析,X-射线衍射,红外光谱,摩尔电导,激光拉曼光谱及差热-热失重分析的研究。     

用草酸胍制备钴酸盐尖晶石

本文采用先驱物法合成钴酸盐尖晶石MCo₂O₄(M=Zn,Ni,Cu,Mg,Cd,Mn)。以草酸胍作为沉淀剂，在溶液中以共沉淀的方法合成草酸盐先驱物。采用热分析(TG和DTA)、化学元素分析、红外光谱等手段对先驱物进行分析表征。通过红外光谱、X射线粉末衍射、扫描电镜对产物进行表征。产物的平均粒度范围在3.5～8.8 μm之间。     

On the construction of periodic solutions of kaplan-yorke type for some differential delay equations

In this paper we point out the main idea to yield periodic solutions of Kaplan-Yorke type of differential delay equations. Some new sufficient conditions for the existence of Kaplan-Yorke type periodic solutions have been given. Many interesting examples are also disscused.     

Formation and tribological properties of two‐component ultrathin ionic liquid films on Si

Several single‐component and two‐component imidazolium ionic liquids (ILs) ultrathin films were formed on Si substrates by a dip‐coating and heat treatment process. The formation and surface properties of the films were analyzed by means of ellipsometric thickness measurement, X‐ray photoelectron spectra and atomic force microscope. The adhesive and nanotribological behaviors of the films were evaluated by a homemade colloidal probe. A ball‐on‐plate tribometer was used to test the microtribological performances of these films. As a result, the two‐component ILs ultrathin film containing 80% solid‐like ILs phase shows more homogenous surface morphologies and optimal micro/nano‐tribological properties as compared to single‐component ILs films, which is ascribed to a synergic effect between the steady solid‐like ILs phase as the backbone and the proper amount of flowable liquid‐like ILs phase. By studying the influence of various solid/liquid ILs ratios on tribological properties of the two‐component ILs films, we might find the way to design ILs films with excellent comprehensive tribological properties. Copyright © 2010 John Wiley & Sons, Ltd.     

Study of Bimodal Drop Size Distributions of Emulsion

In order to increase the present understanding of bimodal emulsion drop size distributions, systematic series of experiments have been carried out to investigate the effects of formulation variables on bimodal drop size distributions, and probability distribution functions were proposed to analyze the distribution. The results show that, the span of the drop size and Sauter mean diameter become larger when the dispersed phase volume fraction becomes higher and rotor speed becomes lower; the Frechet function represents the experimental data satisfactorily. The prediction model of Sauter mean diameter established by combining the prediction theory of the maximum stable drop diameter and experimental analysis results can fit the experimental data well.     

Synthesis and Antitumor Evaluation of Novel Hybrids of Phenylsulfonylfuroxan and Estradiol Derivatives

Fifteen novel furoxan-based nitric oxide (NO) releasing hybrids of estradiol derivatives were synthesized and evaluated in vitro anti-proliferative activity in MDA-MB-231, A2780, Hela and HUVEC cell lines. Most of them displayed potent anti-proliferative effects. Among the compounds, 4-bromo-3-((phenylsulfonyl)-1,2,5-oxadiazole 2-oxide)-oxy-propoxy-estradiol ( 11 b ) exhibited the best activity with IC₅₀ values of 3.58–0.0008 μM. Preliminary pharmacological studies showed that 11 b induced apoptosis and hardly affected the cell cycle of MDA-MB-231 cell line. NO-releasing capacity and inhibition of ERK/MAPK pathway signaling might explain the potent antineoplastic activity of these compounds. The preliminary structure-activity relationship (SAR) showed that steroidal scaffolds with a linker in 3-position were favorable moieties to evidently increase the bioactivities of these hybrids. Overall, these results implied that 11 b merited to be further investigated as a promising anti-cancer candidate.     

The exact solution and integrable properties to the variable-coefficient modified Korteweg-de Vries equation

In this paper, a variable-coefficient modified Korteweg-de Vries (vc-mKdV) equation is investigated. With the help of symbolic computation, the N-soliton solution is derived through the Hirota method. Then the bilinear Bäcklund transformations and Lax pairs are presented. At last, we show some interactions of solitary waves.     

Stability of subharmonics and behaviour of bifurcations to chaos on toral van der pol equation

One of the basic problems in bifurcation theory is to understand the way in which horseshoes are created. In this paper, we study the bifurcation behavior exhibited by the toral Van der Pol equation subject to periodic forcing. Our attention is focased on routes relevant to horseshoes type chaos.The project supported by National Natural Science Foundation of China.