排序方式: 共有63条查询结果,搜索用时 31 毫秒
11.
El-Khouly ME Padmawar P Araki Y Verma S Chiang LY Ito O 《The journal of physical chemistry. A》2006,110(3):884-891
Photoinduced intramolecular processes in a tricomponent molecule C60(>(CN)2-DPAF), consisting of an electron-accepting methano[60]fullerene moiety (C60>) covalently bound to an electron-donating diphenylaminofluorene (DPAF) unit via a bridging dicyanoethylenyl group [(CN)2], were investigated in comparison with (CN)2-DPAF. On the basis of the molecular orbital calculations, the lowest charge-separated state of C60(>(CN)2-DPAF) is suggested to be C60*-(>(CN)2-DPAF*+) with the negative charge localized on the fullerene cage, while the upper state is C60(>(CN)2*--DPAF*+). The excited-state events of C60(>(CN)2-DPAF) were monitored by both time-resolved emission and nanosecond transient absorption techniques. In both nonpolar and polar solvents, the excited charge-transfer state decayed mainly through initial energy-transfer process to the C60 moiety yielding the corresponding 1C60, from which charge separation took place leading to the formation of C60*-(>(CN)2-DPAF*+) in a fast rate and high efficiency. In addition, multistep charge separation from C60(>(CN)2*--DPAF*+) to C60*-(>(CN)2-DPAF*+) may be possible with the excitation of charge-transfer band. The lifetimes of C60*-(>(CN)2-DPAF*+) are longer than the previously reported methano[60]fullerene-diphenylaminofluorene C60(>(C=O)-DPAF) with the C60 and DPAF moieties linked by a methanoketo group. These findings suggest an important role of dicyanoethylenyl group as an electron mediating bridge in C60(>(CN)2-DPAF). 相似文献
12.
13.
The thermoelectric power of ferroelectric sodium vanadate doped with different concentrations of lanthanum oxide has been
measured in the temperature range covering their transition temperatures. It has been observed that the thermoelectric power
increases with temperature, attains maximum value and with further increase in the temperature decreases to zero, indicating
Curie temperature of the respective samples; however, it changes the sign for higher temperature. The thermoelectric power
of sodium vanadate increases to maximum with increase in doping concentration of lanthanum oxide from 0.025 to 0.1 mol%; however,
it decreases for higher concentrations. Pure as well as lanthanum oxide doped sodium vanadate samples showp-type behaviour in the ferroelectric region andn-type behaviour in the paraelectric region. 相似文献
14.
We study the phase synchronization and cluster formation in coupled maps on different networks. We identify two different mechanisms of cluster formation: (a) self-organized phase synchronization which leads to clusters with dominant intracluster couplings and (b) driven phase synchronization which leads to clusters with dominant intercluster couplings. In the novel driven synchronization the nodes of one cluster are driven by those of the others. We also discuss the dynamical origin of these two mechanisms for small networks with two and three nodes. 相似文献
15.
Sarika Goyal K. Sreenadh 《NoDEA : Nonlinear Differential Equations and Applications》2014,21(4):567-588
In this article, we study the Fu?ik spectrum of the fractional Laplace operator which is defined as the set of all \({(\alpha, \beta)\in \mathbb{R}^2}\) such that $$\quad \left.\begin{array}{ll}\quad (-\Delta)^s u = \alpha u^{+} - \beta u^{-} \quad {\rm in}\;\Omega \\ \quad \quad \quad u = 0 \quad \quad \quad \qquad {\rm in}\; \mathbb{R}^n{\setminus}\Omega.\end{array}\right\}$$ has a non-trivial solution u, where \({\Omega}\) is a bounded domain in \({\mathbb{R}^n}\) with Lipschitz boundary, n > 2s, \({s \in (0, 1)}\) . The existence of a first nontrivial curve \({\mathcal{C}}\) of this spectrum, some properties of this curve \({\mathcal{C}}\) , e.g. Lipschitz continuous, strictly decreasing and asymptotic behavior are studied in this article. A variational characterization of second eigenvalue of the fractional eigenvalue problem is also obtained. At the end, we study a nonresonance problem with respect to the Fu?ik spectrum. 相似文献
16.
Hullatti Kirankumar Rodrigues Analee Mannur Vinod Mastiholimath Vinayak Rasal Vijay Kumar 《平面色谱法杂志一现代薄层色谱法》2016,29(5):330-335
JPC – Journal of Planar Chromatography – Modern TLC - Two different botanical sources, Eclipta alba and Wedelia calen-dulacea are used as “Bhringaraja” in the Ayurvedic... 相似文献
17.
Reactions of Pentapseudohalonitrosyl ferrate(II) with Morpholinobenzyl benzamide(MBB) and Piperidinobenzyl benzamide(PBB)
formed complexes of the type, [Fe(X)3(NO)(L–L)] where X = CN−, NCO− and N
3
−
and L–L = Morpholinobenzyl benzamide(MBB) and Piperidinobenzyl benzamide(PBB). These compounds have been characterized
by various physico-chemical techniques such as elemental analysis, molar conductance, magnetic susceptibility measurements,
i.r., electronic spectra, thermal gravimetric analysis. The molecular modeling Studies have been carried out for structural
analysis for some of the complexes have been carried out using Hyperchem release 7.52 professional version. 相似文献
18.
Chawla HM Pant N Kumar S Mrig S Srivastava B Kumar N Black DS 《Journal of photochemistry and photobiology. B, Biology》2011,105(1):25-33
A series of novel calix[4]arene enones (5-7) and cinnamates (12-14) have been synthesized and evaluated for ensuring protection from ultraviolet radiation (UVR). Spectroscopic analyses has revealed that compound 6 absorbs ultraviolet radiations between 280 and 350 nm with an absorption maximum at 312 nm. Its molar absorption coefficient (ε) (>5 × 10(4)M(-1)cm(-1)) and bandwidth are larger than those for the commercially used sun protectants (oxybenzone (OB), 2-ethylhexyl 4-methoxycinnamate (OMC) and avobenzone). The in vitro Sun Protection Factor (SPF) measurement revealed an SPF of 5.2 at 2% concentration of 6 in home made emulsion formulations while combination of 2% each of 6 and OMC gave an SPF of 8.8. Lower sun protection seems to be compensated by significant protection from more harmful UVA radiations (UVA/UVB absorbance ratio of 0.62). 相似文献
19.
Russian Journal of General Chemistry - A novel process to prepare hybrid nanosized neodymium oxybromide and neodymium oxide from neodymium(III) nitrate hexahydrate has been developed. The... 相似文献
20.