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71.
Woongchul Shin Seongmin Park Hyeyoon Ro Dong-Yeun Koh Jiwoong Seol Huen Lee 《The Journal of chemical thermodynamics》2012,44(1):20-25
We suggest two types of new amine-type sII formers: pyrrolidine and piperidine. These guest compounds fail to form clathrate hydrate structures with host water, but instead have to combine with light gaseous guest molecules (methane) for enclathration. First, two binary clathrate hydrates of (pyrrolidine + methane) and (piperidine + methane) were synthesized at various amine concentrations. 13C NMR and Raman analysis were done to identify the clathrate hydrate structure and guest distribution over sII-S and sII-L cages. XRD was also used to find the exact structure and corresponding cell parameters. At a dilute pyrrolidine concentration of less than 5.56 mol%, the tuning phenomenon is observed such that methane molecules surprisingly occupy sII-L cages. At the critical guest concentration of about 0.1 mol%, the cage occupancy ratio reaches the maximum of approximately 0.5. At very dilute guest concentration below 0.1 mol%, the methane molecules fail to occupy large cages on account of their rarefied distribution in the network. Direct-release experiments were performed to determine the actual guest compositions in the clathrate hydrate phases. Finally, we measured the clathrate hydrate phase equilibria of (pyrrolidine + methane) and (piperidine + methane). 相似文献
72.
In this paper, we propose an area preserving bijective map from the regular octahedron to the unit sphere ${\mathbb{S}^2}$ , both centered at the origin. The construction scheme consists of two steps. First, each face F i of the octahedron is mapped to a curved planar triangle ${\mathcal{T}_i}$ of the same area. Afterwards, each ${\mathcal{T}_i}$ is mapped onto the sphere using the inverse Lambert azimuthal equal area projection with respect to a certain point of ${\mathbb{S}^2}$ . The proposed map is then used to construct uniform and refinable grids on a sphere, starting from any triangular uniform and refinable grid on the triangular faces of the octahedron. 相似文献
73.
Wei-Chia Ro Jen-San Chen Shau-Yu Hong 《International Journal of Solids and Structures》2010,47(16):2143-2154
This paper studies the vibration and stability of an elastica constrained by a pair of symmetrically placed parallel plane walls. One end of the elastica is fully clamped, while the other end is allowed to slide through a rigid channel under edge thrust. In order to take into account the variation of the contact points between the elastica and the walls during vibration, an Eulerian version of the equations of motion is adopted. It is found that the lowest few natural frequencies approach and remain degenerately zero when point-contact deformations evolve to line-contact patterns. As a consequence, the stability of all line-contact deformations before secondary buckling cannot be determined from the linear vibration analysis. A load-controlled experiment was conducted to find that the elastica jumped from one-point to two-point, and then to three-point contact with the walls without going through any line-contact deformations. These experimental observations are different from the results reported previously by others with different set-ups, in which line-contact deformations did exist. Explanations based on experimental evidences and theoretical analyses are provided to confirm the validity of these previous investigations and clarify the cause of the difference. 相似文献
74.
75.
A. Prévost N. Buforn A. Astier R. Duffait M. Meyer S. Perriès N. Redon O. Stézowski A. Bauchet I. Deloncle M.G. Porquet A. Görgen H. Hübel E. Mergel S. Neumann D. Roßbach N. Nenoff G. Schönwaßer A.N. Wilson R. Lucas F.A. Beck D. Curien G. Duchêne B.J.P. Gall N. Kintz J.P. Vivien D.M. Cullen 《The European Physical Journal A - Hadrons and Nuclei》2001,10(1):13-19
We report the identification of six new superdeformed (SD) bands in 197,198Pb observed with the EUROBALL IV spectrometer. The results are interpreted in the framework of cranked Hartree-Fock calculations
with approximate projection on the particle number by means of the Lipkin-Nogami method. A mixing between quasi-particle excitations
and an octupole vibration is suggested in the two SD isotopes. We have estimated the ordering of the neutron valence orbitals
and confirm indirectly a N = 118 SD gap.
Received: 20 December 2000 / Accepted: 24 January 2001 相似文献
76.
We construct a realistic nonlinear supersymmetric SU(5) model without superpartner particles in curved space and investigate the Higgs sector in the limit of flat space. We need at least an adjoint-, a quintuplet- and an antiquintuplet-Higgs multiplet. In order to obtain a realistic breakdown of SU(5) to SU(3) × U(1) at tree level we have to modify the vacuum structure of the adjoint representation in comparison to other SU(5)-models. This model requires an “elegant” fine-tuning. We determine the mass spectrum of the electroweak Higgs sector. 相似文献
77.
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79.
Ammar R Baringer P Coppage D Davis R Haas P Kelly M Kwak N Lam H Ro S Kubota Y Nelson JK Perticone D Poling R Schrenk S Crawford G Fulton R Jensen T Johnson D Kagan H Kass R Malchow R Morrow F Whitmore J Wilson P Bortoletto D Brown DN Dominick J McIlwain RL Miller DH Modesitt M Ng CR Schaffner SF Shibata EI Shipsey IP Battle M Kroha H Sparks K Thorndike EH Wang C Alam MS Kim IJ Li WC Nemati B Romero V Sun CR Wang P Zoeller MM Goldberg M Haupt T Horwitz N Jain V Kennett R Mestayer MD Moneti GC 《Physical review D: Particles and fields》1991,44(11):3383-3393
80.
Avery P Freyberger A Rodriguez J Yelton J Henderson S Kinoshita K Pipkin F Saulnier M Wilson R Wolinski J Xiao D Yamamoto H Sadoff AJ Ammar R Baringer P Coppage D Davis R Kelly M Kwak N Lam H Ro S Kubota Y Nelson JK Perticone D Poling R Schrenk S Alam MS Kim IJ Nemati B Romero V Sun CR Wang P Zoeller MM Crawford G Fulton R Gan KK Jensen T Kagan H Kass R Malchow R Morrow F Whitmore J Wilson P Butler F Fu X Kalbfleisch G Lambrecht M Skubic P Snow J Bortoletto D Brown DN Dominick J McIlwain RL 《Physical review letters》1992,68(9):1279-1282