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91.
Journal of Solid State Electrochemistry - Hierarchical nanostructure materials have attracted significant attention due to their fascinating structural features for the application of...  相似文献   
92.
93.
Russian Journal of General Chemistry - In the present study novel 1,2,4-oxadiazolo sulfonamides 3a–3o are synthesized by an efficient method based on the reaction of 1,2,4-oxadiazole amines...  相似文献   
94.
In this paper we show that bounded perturbation of the discrete laplacian with a potential that is sparsely supported (a notion made precise in the paper) produces absolutely continuous spectrum in the interval [?2ν, 2ν] for large dimension ν. We note that the potential need not give rise to a compact operator, let alone have decay at infinity.  相似文献   
95.
Phase pure Zn1?x Co x O thin films grown by pulsed laser deposition have transmittance greater than 75 % in the visible region. Raman studies confirm the crystalline nature of Zn1?x Co x O thin films. Zn0.95Co0.05O thin films show room temperature ferromagnetism with saturation magnetization of 0.4μ B /Co atom. The possible origin of paramagnetism at higher Co doping concentrations can be attributed to the increased nearest-neighbor antiferromagnetic interactions between Co2+ ions in ZnO matrix. XPS confirms the substitution of Co2+ ions into the ZnO host lattice.  相似文献   
96.
A core-envelope model for superdense matter distribution with the feature- core consisting of anisotropic fluid distribution and envelope with isotropic fluid distribution is reported on the background of pseudospheroidal space-time. The physical plausibility of the model is examined analytically and numerically.  相似文献   
97.
This paper describes the preparation and characterization of poly(vinyl alcohol) (PVA)-added ionic liquid-based ion conductors. The polymer electrolyte is incorporated with magnesium triflate [Mg(CF3SO3)2 or MgTf] as salt and 1-butyl-3-methylimidazolium bromide (BmImBr) as ionic liquid. Differential scanning calorimetry (DSC) is carried out to investigate the glass transition temperature which is used to study the plasticizing effect of the ionic liquid. The highest conducting ionic liquid-based polymer electrolyte is used to fabricate electrical double-layer capacitors (EDLC). The electrochemical potential window is evaluated using linear sweep voltammetry (LSV). The electrochemical capacitance of the EDLC is evaluated through cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD). The electrochemical potential window of ionic liquid-added polymer electrolyte is extended from 1.35 to 2.6 V. Cyclic voltammetry (CV) proves the improvement in specific capacitance of the electrical double-layer capacitors (EDLCs) containing ionic liquid-added polymer electrolyte.  相似文献   
98.
Oxygen maps derived from electron paramagnetic resonance spectral-spatial imaging (EPRI) are based upon the relaxivity of molecular oxygen with paramagnetic spin probes. This technique can be combined with MRI to facilitate mapping of pO(2) values in specific anatomic locations with high precision. The co-registration procedure, which matches the physical and digital dimensions of EPR and MR images, may present the pO(2) map at the higher MRI resolution, exaggerating the spatial resolution of oxygen, making it difficult to precisely distinguish hypoxic regions from normoxic regions. The latter distinction is critical in monitoring the treatment of cancer by radiation and chemotherapy, since it is well-established that hypoxic regions are three or four times more resistant to treatment compared to normoxic regions. The aim of this article is to describe pO(2) maps based on the intrinsic resolution of EPRI. A spectral parameter that affects the intrinsic spatial resolution of EPRI is the full width at half maximum (FWHM) height of the gradient-free EPR absorption line in frequency-encoded imaging. In single point imaging too, the transverse relaxation times (T(2)(?)) limit the resolution since the signal decays by exp(-t(p)/T(2)(?)) where the delay time after excitation pulse, t(p), is related to the resolution. Although the spin densities of two point objects may be resolved at this separation, it is inadequate to evaluate quantitative changes of pO(2) levels since the linewidths are proportionately affected by pO(2). A spatial separation of at least twice this resolution is necessary to correctly identify a change in pO(2) level. In addition, the pO(2) values are blurred by uncertainties arising from spectral dimensions. Blurring due to noise and low resolution modulates the pO(2) levels at the boundaries of hypoxic and normoxic regions resulting in higher apparent pO(2) levels in hypoxic regions. Therefore, specification of intrinsic resolution and pO(2) uncertainties are necessary to interpret digitally processed pO(2) illustrations.  相似文献   
99.
A general, parallel, and collective synthesis of 5/5/5‐ and 5/5/6‐ring fusion topologies of tricyclic spiranoid lactones through the controlled cyclizations of easily accessible, common key precursors is described. The rapid composition of key cycloalkyl methylene precursors yielded an assembly of bicyclic diastereoisomeric iodolactones, which were individually converted into a wide range of tricyclic, angularly fused spiranoid lactones in a regioselective and stereodirected fashion through the diastereoisomeric differentiation of a collective key precursor. The critical stereochemical assignment of the bicyclic starting materials, as well as the tricyclic targets, was confirmed by X‐ray crystal structure determination.  相似文献   
100.
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