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排序方式: 共有119条查询结果,搜索用时 15 毫秒
61.
S. Brant V. Paar G. Lhersonneau O. W. B. Schult H. Seyfarth K. Sistemich 《Zeitschrift für Physik A Hadrons and Nuclei》1989,334(4):517-518
Extrapolating the Interacting Boson-Model treatment from lighter neighbours to98Y we predict the properties of low-lying states of spherical nature in IBFFM. This odd-odd nucleus which presents one of the rare cases of coexisting spherical and deformed shapes is of fundamental importance for understanding nuclear phase transitions. 相似文献
62.
We give two constructions of sets of masks on cograssmannian permutations that can be used in Deodhar’s formula for Kazhdan–Lusztig basis elements of the Iwahori–Hecke algebra. The constructions are respectively based on a formula of Lascoux–Schützenberger and its geometric interpretation by Zelevinsky. The first construction relies on a basis of the Hecke algebra constructed from principal lower order ideals in Bruhat order and a translation of this basis into sets of masks. The second construction relies on an interpretation of masks as cells of the Bott–Samelson resolution. These constructions give distinct answers to a question of Deodhar. 相似文献
63.
M.E. Cage D.L. Clough A.J. Cole J.B.A. England G.J. Pyle P.M. Rolph L.H. Watson D.H. Worledge 《Nuclear Physics A》1972
Differential cross sections have been measured for the elastic scattering of 33 MeV 3He particles from targets of 58,60,62,64Ni,63,65Cu and 64,66,68Zn over the angular range 5° to 175°. The data have been analysed with the optical model, with particular emphasis on the investigation of the ambiguities in the real potential, the form of the imaginary potential and the use of a spin-orbit term. 相似文献
64.
Using the ligand group shift model to calculate metal binding energies (BE's), comparisons of BE(calc) and BE(obs) values reveal a correlation between relaxation energy and the extent of metal—metal bonding. No significant difference in relaxation energy is detected between monometal complexes and the dipalladium complexes which contain a single MM bond. However, substantially larger relaxation energies (1–2 eV) relative to monometal complexes are found for multiply MM-bonded complexes. The magnitude of the additional relaxation energy is in the range expected on the basis of comparisons with other systems. 相似文献
65.
A. Marinov W. Oelert S. Gopal B. Brinkmöller G. Hlawatsch C. Mayer-Böricke J. Meissburger D. Paul M. Rogge J.G.M. Römer J.L. Tain P. Turek L. Zemlo R.B.M. Mooy P.W.M. Glaudemans S. Brant V. Paar M. Vouk V. Lopac 《Nuclear Physics A》1985,438(2):429-449
The 58Ni(d, 3He)57Co reaction was measured at a bombarding energy of 78 MeV. Energy levels up to 7.0 MeV excitation energy in 57Co were studied. Angular distributions of the 3He particles, corresponding to transitions to the ground state and to 42 excited states in 57Co, were analyzed in the range of θlab = 2.7° to 25°. Exact finite-range DWBA calculations were employed to extract l-values and spectroscopic factors. Shell-model calculations were carried out in an fp-shell model space. In addition, calculations of the energy levels in 57Co were performed in the SU(6) particle-vibration model (PTQM). Satisfactory agreement is observed between the experimental results and both theoretical predictions. 相似文献
66.
67.
Kimberly A. Chaffin Frank S. Bates Patrick Brant Gary M. Brown 《Journal of Polymer Science.Polymer Physics》2000,38(1):108-121
The low‐temperature mechanical behavior of semicrystalline polymer blends is investigated. Isotactic polypropylene (iPP) is blended with both Zeigler–Natta polyethylene (PE) and metallocene PE. Transmission electron microscopy (TEM) on failed tensile bars reveals that the predominate failure mode in the Zeigler–Natta blend is interfacial, while that in the metallocene blend is failure of the iPP matrix. The observed change in failure mode is accompanied by a 40% increase in both tensile toughness and elongation at −10 °C. We argue that crystallite anchoring of interfacially entangled chains is responsible for this dramatic property improvement in the metallocene blend. The interfacial width between PE and iPP melts is approximately 40 Å, allowing significant interfacial entanglement in both blends. TEM micrographs illustrate that the segregation of low molecular weight amorphous material in the Zeigler–Natta blend reduces the number and quality of crystallite anchors as compared with the metallocene blend. The contribution of anchored interfacial structure was further explored by introducing a block copolymer at the PE/iPP interface in the metallocene blend. Small‐angle X‐ray scattering (SAXS) experiments show the block copolymer dilutes the number of crystalline anchors, decoupling the interface. Increasing the interfacial coverage of the block copolymer reduces the number of anchored interfacial chains. At 2% block copolymer loading, the low‐temperature failure mode of the metallocene blend changes from iPP failure to interfacial failure, reducing the blend toughness and elongation to that of the Zeigler–Natta blend. This work demonstrates that anchored interfacial entanglements are a critical factor in designing semicrystalline blends with improved low‐temperature properties. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 108–121, 2000 相似文献
68.
Johnson MD Lorenz BB Wilkins PC Lemons BG Baruah B Lamborn N Stahla M Chatterjee PB Richens DT Crans DC 《Inorganic chemistry》2012,51(5):2757-2765
The kinetics of reduction of two cobalt(III) complexes with similar redox potentials by hexacyanoferrate(II) were investigated in water and in reverse micelle (RM) microemulsions. The RMs were composed of water, surfactant [(sodium(bis(2-ethylhexylsulfosuccinate)), NaAOT], and isooctane. Compared to the reaction in water, the reduction rates of (ethylenediaminetetraacetato)cobaltate(III) by hexacyanoferrate(II) were dramatically suppressed in RM microemulsions whereas a slight rate increase was observed for reduction of bis-(2,6-dipicolinato)cobaltate(III). For example, the ferrocyanide reduction of [Co(dipic)(2)](-) increased from 55 M(-1) s(-1)in aqueous media to 85 M(-1) s(-1) in a w(o) = 20 RM. The one-dimensional (1-D) and two-dimensional (2-D) (1)H NMR and FT-IR studies are consistent with the reduction rate constants of these two complexes being affected by their location within the RM. Since reduction of [Co(edta)](-) is switched off, in contrast to [Co(dipic)(2)](-), these observations are attributed to the penetration of the [Co(edta)](-) into the interfacial region of the RM whereas [Co(dipic)(2)](-) is in a region highly accessible to the water pool and thus hexacyanoferrate(II). These results demonstrated that compartmentalization completely turns off a redox reaction in a dynamic microemulsion system by either reactant separation or alteration of the redox potentials of the reactants. 相似文献
69.
Ab Rani MA Brant A Crowhurst L Dolan A Lui M Hassan NH Hallett JP Hunt PA Niedermeyer H Perez-Arlandis JM Schrems M Welton T Wilding R 《Physical chemistry chemical physics : PCCP》2011,13(37):16831-16840
The polarities of a wide range of ionic liquids have been determined using the Kamlet-Taft empirical polarity scales α, β and π*, with the dye set Reichardt's Dye, N,N-diethyl-4-nitroaniline and 4-nitroaniline. These have been compared to measurements of these parameters with different dye sets and to different polarity scales. The results emphasise the importance of recognising the role that the nature of the solute plays in determining these scales. It is particularly noted that polarity scales based upon charged solutes can give very different values for the polarity of ionic liquids compared to those based upon neutral probes. Finally, the effects of commonplace impurities in ionic liquids are reported. 相似文献
70.
Huyang G Canning J Åslund ML Naqshbandi M Gibson B Petermann I Stocks D Crossley MJ 《Optics letters》2011,36(11):1975-1977
We constructed a type of sensor by depositing a solgel layer within the interior holes of a silica-structured fiber and, subsequently, coating this with an acid-responsive porphyrin. Protonation of the porphyrin by an acidic gas (HCl in this case), is detected by a large change in the visible spectrum. Compared to previous work on a liquid-core sensor in a structured optical fiber, the signal-to-noise ratio of this gas sensor shows a reduced signal strength, but the detection rate is increased about fortyfold. 相似文献