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We compute the noncommutative de Rham cohomology for the finite dimensional q-deformed coordinate ring q [SL2] at odd roots of unity and with its standard four-dimensional differential structure. We find that H i is highly nontrivial compared to case of generic q and has as many modes 1 : 4 : 6 : 4 : 1 as the dimension of the exterior algebra. We solve the spin-0 and Maxwell theory on q [SL2], including a complete picture of the self-dual and anti-self dual solutions and of Lorentz and temporal gauge fixing. The system behaves in fact like a noncompact space with self-propagating modes (i.e., in the absence of sources). We also solve with examples of electric and magnetic sources including the biinvariant element H 1 which we find can be viewed as a source in the local (Minkowski) time-direction (i.e. a uniform electric charge density).  相似文献   

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Molecular Diversity - Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides,...  相似文献   

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采用比较分子场分析方法(CoMFA)和比较分子相似性指数分析方法(CoMSIA)对一系列吡啶并嘧啶类衍生物进行了三维定量构效关系(3D-QSAR)研究,建立了CoMFA和CoMSIA两种模型. 所构建的最佳模型的交叉验证相关系数分别为0.707和0.645,非交叉验证系数分别是0.964和0.972,模型的一些外部验证表明两个模型合理、可靠,并具有良好的预报能力. 同时,用分子对接的方法分析了该类化合物与Wee1激酶结构的作用模式,结果进一步表明,在R1和R5取代基上引入正电性基团,R2为体积小的电负性基团,同时选择体积中等和强的推电子的R3但亲水性的X取代基,能有效改善这类化合物的抑制活性.  相似文献   

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Physics of Atomic Nuclei - The results obtained by experimentally and theoretically studying the yield of the promising nuclear-fusion reaction $${}^{11}$$ B( $$p,3\alpha$$ ) initiated by powerful...  相似文献   

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A series of novel substituted 1,3,4-oxadiazole derivatives containing pyrido[1,2-a]benzimidazole moiety were synthesized and characterized using FTIR, 1H NMR, 13C NMR, and HRMS. An efficient tandem reaction was employed as a key step in constructing the pyrido[1,2-a]benzimidazole moiety under very mild condition. The structure of compound 4a was established by X-ray crystallography. The UV-vis absorption and fluorescence spectral characteristics of these compounds were investigated in several solvents. Compounds 4a-i display similar absorptions, with absorption peaks ranging from 330 to 339 nm in acetonitrile, while the absorption maxima of compound 4j bearing a diphenylamino group on the benzene ring is red-shifted distinctly to 377 nm due to the strong electron-donating property of its substituent and extended π-conjugated system. All these target heterocyclic compounds present blue-green emissions (461-487 nm) in dilute solutions and show high quantum yields of fluorescence (ФPL=0.65−0.99) in dichloromethane.  相似文献   

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1-苯甲酰基-3-萘基硫脲在醋酸锰作用下,自身发生关环反应成功获得目标产物N-2-萘并[1,2-d]噻唑基苯甲酰胺,其结构经红外光谱、氢谱和碳谱得到了确证.  相似文献   

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在对一系列抗癌性7,8-二烃基-1,3-二氨基吡咯-[3,2-f]喹唑啉类二氢叶酸还原酶抑制剂的二维定量构效关系(2D-QSAR)研究基础上,应用比较分子场分析法对该类配合物进行了三维定量构效关系(3D-QSAR)研究. 建立了具有良好的统计学性能及预报能力的3D-QSAR模型,非交叉验证相关系数为0.993,交叉验证相关系数为0.619,估算的标准误差0.208, 统计方差比193.4. 该模型表明立体场因素的影响比静电场因素大很多,此结果与我们已经报道的2D-QSAR模型结果相一致. 然而,3D-QS  相似文献   

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A library of new (1,5,3-dithiazepan-3-yl)alkanoic acids was prepared by the multicomponent cyclocondensation of amino acids, formaldehyde, and 1,2-ethanedithiol in water at room temperature for 1 to 5 h in high yields. This green procedure offers several advantages such as an operational simplicity, no catalyst, and no production of hazardous materials.  相似文献   

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The effect of nonstoichiometry on the mechanical properties of Ni3Ge single crystals with the [\(\bar 2\)34] orientation of the deformation axis, which is suitable to cubic slip, has been investigated. The influence of change in the Ge concentration on the Ni3Ge plastic properties under the conditions of cubic slip is established. The concentration dependence of the yield stress at different temperatures is obtained.  相似文献   

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Under solvent-free high-speed ball milling, an I\(_{2}\)-promoted condensation/cyclization of easily available methyl ketones or 1,3-dicarbonyl compounds with 2-aminopyridines has been developed, which allows the quick assembly of 2,3-substituted imidazo[1,2-a]pyridines (IPs) with broad molecular diversity, including the antiulcer drug zolimidine. The advantages of high yields, good functional group compatibility, short reaction time (within 90 min), free use of heating, solvent and metal, employment of cheap starting materials, and simple work-up procedure make this protocol a very efficient alternative to traditional synthesis of IPs.  相似文献   

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An efficient and diastereoselective synthetic procedure for highly functionalized tetrahydroacenaphtho[1,2- \(b\) ]indolone derivatives was successfully developed by the three-component reaction of acenaphthequinone, enaminones, and barbituric acid in the presence of a catalytic amount of L-proline. This method has the advantages of convenient operation, excellent yields, mild reaction conditions, and environmental friendliness.  相似文献   

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Cobalt (Co) nanocapsules coated with boron nitride (BN) layers were synthesized by annealing of ammine complex. KBH4 and [Co(NH3)6]Cl3 were used as starting materials, and annealed these powders at 500–1000 °C with flowing nitrogen gas. Formation of fcc-Co nanocapsules coated with BN layers was observed from X-ray diffraction patterns and high-resolution electron microscopy. Particle size of fcc-Co prepared at 1000 °C with flowing 100 sccm N2 gas was approximately 40 nm, and the values of saturation magnetization and coercivity were 74.5 emu/g and 88 Oe, respectively. Good oxidation- and wear-resistances were obtained by encapsulating Co nanoparticles with BN layers.  相似文献   

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