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151.
We reinvestigate the collective effects of the retardation as well as the bending on the Coulomb excitation cross sections and also on the B(E2) strengths of some neutron-rich isotopes using the intermediate energy Coulomb excitation theory. It is found that the B(E2) strengths extracted from the experimental Coulomb excitation cross section data get suppressed approximately by 6%. Furthermore, the obtained B(E2) strengths in the energy range 30-100 MeV/A are found to be in better agreement with the corresponding values known from other sources, than those obtained by using the recoil-corrected relativistic Coulomb excitation theory. 相似文献
152.
This paper deals with FRW-Cosmological model of the universe for conharmonically flat space time. Einstein field equations with variable cosmological term are solved by using a law of variation for Hubble’s parameter, which is related to average scale factor. A new class of exact solution of the field equation has been obtained in which cosmological-term decreases with cosmic time. A detailed study of physical and kinematical properties of the model is also carried out. 相似文献
153.
154.
Let ${{\mathcal P},}$ where ${|{\mathcal P}| \geq 2,}$ be a set of points in d-dimensional space with a given metric ρ. For a point ${p \in {\mathcal P},}$ let r p be the distance of p with respect to ρ from its nearest neighbor in ${{\mathcal P}.}$ Let B(p,r p ) be the open ball with respect to ρ centered at p and having the radius r p . We define the sphere-of-influence graph (SIG) of ${{\mathcal P}}$ as the intersection graph of the family of sets ${\{B(p,r_p)\ | \ p\in {\mathcal P}\}.}$ Given a graph G, a set of points ${{\mathcal P}_G}$ in d-dimensional space with the metric ρ is called a d-dimensional SIG-representation of G, if G is isomorphic to the SIG of ${{\mathcal P}_G.}$ It is known that the absence of isolated vertices is a necessary and sufficient condition for a graph to have a SIG-representation under the L ∞-metric in some space of finite dimension. The SIG-dimension under the L ∞-metric of a graph G without isolated vertices is defined to be the minimum positive integer d such that G has a d-dimensional SIG-representation under the L ∞-metric. It is denoted by SIG ∞(G). We study the SIG-dimension of trees under the L ∞-metric and almost completely answer an open problem posed by Michael and Quint (Discrete Appl Math 127:447–460, 2003). Let T be a tree with at least two vertices. For each ${v\in V(T),}$ let leaf-degree(v) denote the number of neighbors of v that are leaves. We define the maximum leaf-degree as ${\alpha(T) = \max_{x \in V(T)}}$ leaf-degree(x). Let ${ S = \{v\in V(T)\|\}}$ leaf-degree{(v) = α}. If |S| = 1, we define β(T) = α(T) ? 1. Otherwise define β(T) = α(T). We show that for a tree ${T, SIG_\infty(T) = \lceil \log_2(\beta + 2)\rceil}$ where β = β (T), provided β is not of the form 2 k ? 1, for some positive integer k ≥ 1. If β = 2 k ? 1, then ${SIG_\infty (T) \in \{k, k+1\}.}$ We show that both values are possible. 相似文献
155.
Dipti Reetesh Kumar Gangwar Rajesh Srivastava Allan Daniel Stauffer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2013,67(10):1-9
Our recently developed collisional-radiative model which included fine-structure cross sections calculated with a fully relativistic distorted-wave method [R.K. Gangwar, L. Sharma, R. Srivastava, A.D. Stauffer, J. Appl. Phys. 111, 053307 (2012)] has been extended to study non-Maxwellian inductively coupled argon plasmas. We have added more processes to our earlier collisional-radiative model by further incorporating relativistic distorted-wave electron impact cross sections from the 3p 54sJ = 0, 2 metastable states, (1s 3, 1s 5 in Paschen’s notation) to the 3p 55p (3p i ) excited states. The population of various excited levels at different pressures in the range of 1–25 mTorr for an inductively coupled argon plasma have been calculated and compared with the recent optical absorption spectroscopy measurements as well as emission model results of Boffard et al. [Plasma Sources Sci. Technol. 19, 065001 (2010)]. We have also calculated the intensities of two emission lines, 420.1 nm (3p 9 → 1s 5) and 419.8 nm (3p 5 → 1s 4) and compared with measured intensities reported by Boffard et al. [J. Phys. D 45, 045201 (2012)]. Our results are in good agreement with the measurements. 相似文献
156.
A facile one-pot synthesis of N-fused 1,2,4-triazoles from heterocyclic hydrazines and aldehydes is reported. The reaction is efficiently promoted by chromium (VI) oxide to afford the desired products mostly in high yields and in relatively short time. The high yield of the products and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities. 相似文献
157.
A facile one-pot synthesis of 3,5-diarylisoxazoles from α,β-unsaturated ketones and hydroxylamine hydrochloride is reported. The reaction is efficiently promoted by catalytic CuBr2 and Oxone to afford the desired products mostly in high yields and in relatively short time. The mild nature of the synthesis and short reaction time are notable advantages of the developed protocol. This protocol is effective toward various substrates having different functionalities. 相似文献
158.
In the present work, four-layer polymeric waveguides have been fabricated and characterized by interchanging the film layer. Using polyvinyl alcohol (PVA) and styrene acrylonitrile (SAN) polymer it has been shown that polymers do not loose their own property in multilayer structure and better efficiency can be achieved in the form of low propagation losses and mode filtration. Due to high contrast of PVA and SAN films, a broad spectrum of refractive index in four-layer structure has been achieved. 相似文献
159.
M. Narasimhulu S. Malla Reddy K. Rajesh N. Suryakiran D. Ramesh Y. Venkateswarlu 《Heteroatom Chemistry》2008,19(4):429-433
A mild and highly efficient synthesis of chiral tetrahydroquinolino pyranose derivatives is described. The reaction of a chiral α,β‐unsaturated aldehyde containing a hydroxyl group with different aryl amines using lanthanum(III) nitrate hexahydrate as a catalyst afforded corresponding chiral tetrahydroquinolinated pyranosides in excellent yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:429–433, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20441 相似文献
160.
Hruška Branislav Dagupati Rajesh Chromčíková Mária Nowicka Aleksandra Macháček Jan Liška Marek Munoz Francisco 《Journal of Thermal Analysis and Calorimetry》2020,142(5):2025-2031
Journal of Thermal Analysis and Calorimetry - The structure of binary glasses xMgO·(1?x)P2O5 (x?=?0.30, 0.35, 0.40, 0.45, 0.50, and 0.55) was studied by thermodynamic model... 相似文献