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11.
非线性奇异边值问题的正解 总被引:1,自引:0,他引:1
路慧芹 《应用泛函分析学报》2002,4(3):217-221
利用锥映射的不动点指数定量,研究了一类非线性奇异边值问题多个正解的存在性问题。在构造的解的存在条件之下,证明了奇异边值问题至少有两个正解的存在性定理。 相似文献
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A Promising MoO_x-based Catalyst for n-Heptane Isomerization 总被引:1,自引:0,他引:1
Song Hai CHAI Xin Ping WANG* Ying Jun WANG Tian Xi CAI State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 《中国化学快报》2003,14(7)
The increasing demand for higher-octane gasoline and the regulations limiting the amount of aromatics in the fuel motivate the interest in catalytic isomerization of n-alkanes. In the last ten years, transition metal oxides or oxycarbides based on molybdenum or tungstate have attracted much attention due to their high activity and isomerization selectivity compared to the conventional bifunctional supported platinum catalyst and high resistance to sulphur and nitrogen catalyst poisons1-5. Ma… 相似文献
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A new electroactive polynuclear inorganic compound of rare earth metal, gadolinium hexacyanoferrate (GdHCF), was prepared and characterized using the techniques of FTIR spectroscopy, thermogravimetric analysis (TG), UV-Vis spectrometry, X-ray photoelectron spectroscopy (XPS), ICP atomic emission spectroscopy, and EDX. The results of ICP atomic emission spectroscopy, EDX, and TGA indicated that the prepared GdHCF sample had a stoichiometry of NaGdFe(CN)6·12H2O (when GdHCF was prepared in NaCl solution). The FTIR spectrum of GdHCF showed that there were two types of water molecules in the structure of GdHCF: one was the interstitial water (5 H2O), which resulted from the association of water due to H-bonding, and the other was water coordinated with Gd (7 H2O). The results obtained using XPS showed that the oxidation state of Fe and Gd in the GdHCF sample was +2 and +3, respectively. GdHCF was immobilized on the surface of spectroscopically pure graphite (SG) electrode forming the GdHCF/SG electrode, and the solid-state electrochemistry of the resultant electrode was studied using cyclic voltammetry. The cyclic voltammetric results indicated that the GdHCF/SG electrode exhibited a pair of well-defined and stable redox peaks with the formal potential of E0′=(197±3) mV. The effects of the concentration of the supporting electrolyte on the electrochemical characteristics of GdHCF were studied, and the results showed that the value of E0′ increased linearly with the activity of the cationic ion of the supporting electrolyte (lgaNa+), with a slope of 54.1 mV, which may become a novel method for determining the activity of Na+ in solution. Further experimental results indicated that GdHCF had electrocatalytic activities toward the oxidation of dopamine (DA) and ascorbic acid (AA), and the electrocatalytic current increased linearly with the concentration of DA (or AA) in the range of 1.0–10.0 mmol·L?1 (for DA) or 0.5–20.0 mmol·L?1 (for AA). 相似文献
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建立了相变热力学理论和场论的关系. 强调在量子场论中必须引进序参量场, 则相变的讨论就类似于Goldstone bosons 的产生. 如果只讨论一级相变, Goldstone bosons场就足够了; 如果要讨论二级相变, 则必须讨论一系列的场, 这些场构成一个对称群的表示. 另外, 也将这一思想用到色超导中. In this paper we built a relation between the thermodynamical theory of the phase transition and field theory. We emphasized that in the quantum field theory we have to introduce the order parameter fields. Then the discussion of the phase transition is closed to the creation of the Goldstone bosons. If we only discuss the first order transition, the Goldstone bosons fields are sufficient. If we want to discuss the second order transition, we have to discuss a set of fields that constructs a representation of a symmetry group. We also apply this concept to color superconductivity. 相似文献
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Mao‐Chuan Yuan Ping‐I Shih Chen‐Han Chien Ching‐Fong Shu 《Journal of polymer science. Part A, Polymer chemistry》2007,45(14):2925-2937
We have synthesized a blue‐light‐emitting polyfluorene (PF) derivative ( PF‐CBZ‐OXD ) that presents bulky hole‐transporting carbazole and electron‐transporting oxadiazole pendent groups functionalized at the C‐9 positions of alternating fluorene units. The results from photoluminescence and electrochemical measurements indicate that both the side chains and the PF main chain retain their own electronic characteristics in the copolymer. An electroluminescent device incorporating this polymer as the emitting layer was turned on at 4.5 V; it exhibited a stable blue emission with a maximum external quantum efficiency of 1.1%. Moreover, we doped PF‐CBZ‐OXD and its analogue PF‐TPA‐OXD with a red‐light‐emitting iridium phosphor for use as components of phosphorescent red‐light emitters to investigate the effect of the host's HOMO energy level on the degree of charge trapping and on the electrophosphorescent efficiency. We found that spectral overlap and individual energy level matching between the host and guest were both crucial features affecting the performance of the electroluminescence devices. Atomic force microscopy measurements indicated that the dipolar nature of PF‐CBZ‐OXD , in contrast to the general nonpolarity of polydialkylfluorenes, provided a stabilizing environment that allowed homogeneous dispersion of the polar iridium triplet dopant. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2925–2937, 2007 相似文献
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