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11.
12.
K. Ruegg 《Colloid and polymer science》1927,41(3):275-276
Zusammenfassung Es wird auf die Eigenschaft der galvanokolloiden Metallhydroxyde hingewiesen, in Salzl?sung hydrolytische Spaltungen zu bewirken
und bald die S?ure, bald die Base zu adsorbieren, ein Vorgang der für die Wasserenth?rtung sowie die Theorie der Anfressung
von Metallen Bedeutung besitzt. 相似文献
13.
Alberto Albinati Urs Von Gunten Paul S. Pregosin Hubert J. Ruegg 《Journal of organometallic chemistry》1985,295(2):239-256
195Pt, 119Sn and 31P NMR characteristics of the complexes trans-[Pt(SnCl3)(carbon ligand)(PEt3)2] (1a-1e) are reported, (carbon ligand = CH3 (1a), CH2Ph (1b), COPh (1c), C6Cl5 (1d), C6Cl4Y (e); Y = meta- and para-NO2, CF3, Br, H, CH3, OCH3, or Pt(SnCl3)(PEt3)2. The values of 1J(195Pt, 119Sn) vary from 2376 to 11895 Hz with the COPh ligand having the smallest and the C6Cl5 ligand the largest value, making a total range for this coupling constant, when the dimer syn-trans-[PtCl(SnCl3)(PEt3)]2 is included, of ca. 33000 Hz. In the meta- and para-substituted phenyl complexes 1J(195Pt, 119Sn) (a) is greater for electron-withdrawing substituents, (b) varies more for the meta-substituted derivatives (5634 to 7906 Hz) than for the para analogues (6088 to 7644 Hz) and (c) has the lowest values when the Pt(SnCl3)(PEt3)2 group is the meta- or para-substituent. The direction of the change in 1J(195Pt, 119Sn) is opposite to that found for 1J(195Pt, 119P). For the aryl complexes linear correlations are observed between δ(119Sn), 1J(195Pt, 119Sn), 1J(195Pt, 31P), 1J(119Sn, 31P) and the Hammett substituent constant σn. δ(119Sn) and 1J(195Pt, 119Sn) are related linearly to v(Pt-H) in the complexes trans-[PtH(C6H4Y)(PEt3)2]; δ(119Sn) and δ(1H) (hydride) are also linearly related. Based on 1J(195Pt, 119Sn), the acyl ligand is suggested to have a very large NMR trans influence. The differences in the NMR parameters for (1a-e) are rationalized in terms of differing σ- and π-bonding abilities of the carbon ligands.The structure of 1c has been determined by crystallographic methods. The complex has a slightly distorted square planar geometry with trans-PEt3 ligands. Relevant bond lengths (Å) and bond angles (°) are: PtSn, 2.634(1), PtP, 2.324(4) and 2.329(4), PtC, 2.05(1); PPtP, 170.7(6), SnPtC, 173.0(3), SnPtP, 92.1(1), 91.7(1), PPtC, 88.8(4) and 88.3(4). The PtSn bond separation is the longest yet observed for square-planar platinum trichlorostannate complexes, and would be consistent with a large crystallographic trans influence of the benzoyl ligand. The PtSn bond separation is shown to correlate with 1J(195Pt, 119Sn). 相似文献
14.
A Gurtu P K Malhotra I S Mittra P M Sood SC Gupta VK Gupta GL Kaul LK Mangotra Y Prakash NK Rao ML Sharma 《Pramana》1974,3(5):311-322
This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR em = 〈n s〉/〈n ch〉, where 〈n ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R em = 1·71 implies an effectiveA-dependence ofR A =A 0.18,i.e., a very weak dependence. Predictions ofR em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production. 相似文献
15.
Henri Bacry Henri Ruegg Jean-Marie Souriau 《Communications in Mathematical Physics》1966,3(5):323-333
The one particle problem in a spherical potential is examined in Classical Mechanics from a group theorical point of view. The constants of motion are classified according to their behaviour under the rotation groupSO(3), i.e. according to the irreducible representationsD
j
ofSO(3) (section 1).The Lie algebras ofSO(4) andSO(3) are explicitly built in terms of Poisson brackets for an arbitrary potential, from global considerations. The Kepler and the 3 dimensional oscillator problems are shown to play particular roles with respect to these groups (sections 2 and 3).In the last section, the Kepler problem is analyzed with the aid of theSO(4) group instead of the Lie algebra. It is proved that the transformations generated by the angular momentum and the Runge-Lenz vector form indeed a group of canonical transformations isomorphic toSO(4). Consequences with respect to the quantization problem are examined. 相似文献
16.
A Soibel SS Banerjee Y Myasoedov ML Rapparort E Zeldov S Ooi T Tamegai 《Pramana》2002,58(5-6):893-898
Using a novel differential magneto-optical imaging technique we investigate the phenomenon of vortex lattice melting in crystals
of Bi2Sr2CaCu2O8 (BSCCO). The images of melting reveal complex patterns in the formation and evolution of the vortex solid-liquid interface
with varying field (H)/temperature (T). We believe that the complex melting patterns are due to a random distribution of material disorder/inhomogeneities across
the sample, which create fluctuations in the local melting temperature or field value. To study the fluctuations in the local
melting temperature/field, we have constructed maps of the melting landscape T
m(H, r), viz., the melting temperature (T
m) at a given location (r) in the sample at a given field (H). A study of these melting landscapes reveals an unexpected feature: the melting landscape is not fixed, but changes rather
dramatically with varying field and temperature along the melting line. It is concluded that the changes in both the scale
and shape of the landscape result from the competing contributions of different types of quenched disorder which have opposite
effects on the local melting transition. 相似文献
17.
Jerzy Lukierski
Anatol Nowicki
Henri Ruegg
《Journal of Geometry and Physics》1993,11(1-4):425-436A new real quantum Poincaré algebra which is a standard *-Hopf algebra is obtained by the construction of Uq (O(3,2)) (q real). The deformation parameter K is mass-like, and the classical Poincaré algebra is obtained in the limit K → ∞. For our K-Poincaré algebra both Casimirs are given. 相似文献
18.
The null-plane dynamics of hydrogen-like atoms is studied in approximations depending on c, the velocity of light, being large. Neglecting terms in the Hamiltonian of order c?3 (relative to electron rest energy) a symmetry SU (2)W appears which is analogous to the SU (6)W of hadron classification. This symmetry, if accurate, would dictate zero ground state magnetic moment. The symmetry is broken by terms of third order, which can, however, be transformed a way by the appropriate approximation to the Melosh transformation. There then emerges a better symmetry, SU (2)M, broken only at fourth order. The ground state magnetic moment acquires its usual non-relativistic value. The symmetry SU (2)M corresponds to a subgroup of a symmetry [U (2) × U (2)]FW which appears in the old Foldy-Wouthuysen approach when spin-orbit coupling is neglected. As well as “current” and “constituent” pictures, “classification” pictures are distinguished; it is to one of the latter that the Melosh transformation transforms. 相似文献
19.
Reynolds BJ Ruegg ML Balsara NP Radke CJ 《Langmuir : the ACS journal of surfaces and colloids》2006,22(22):9201-9207
In a companion preceding paper, we presented an experimental investigation into the adsorption dynamics of a diblock copolymer surfactant to a polymer/polymer interface and found them to be well-described by a microscopic model of diffusion in a potential generated using self-consistent field theory. We compare the predictions of the microscopic approach with a macroscopic (adsorption-diffusion) model and demonstrate the equivalence of the two models when the free-energy well underlying surfactant adsorption is flanked by barriers that are significantly larger than thermal energy (kT). However, when the energy barriers are nonexistent, as is the case for the experimental system of interest, a finite interfacial width must be introduced into the classical model to obtain physically meaningful results (i.e., nonnegative desorption rates). Surprisingly, we find that the predictions of the macroscopic finite interfacial width model with no adjustable parameters are in excellent agreement with experimental data presented in the companion paper even though the latter was obtained with molecular resolution. This agreement provides insight into aspects of the free-energy landscape that determine surfactant transport. 相似文献
20.
Ekiel-Jezewska ML; Wajnryb E 《The Quarterly Journal of Mechanics and Applied Mathematics》2006,59(4):563-585
An example system is studied to discuss precision of the multipoleexpansion, applied to determine forces exerted on particlesby a viscous low-Reynolds-number fluid flow. A single spherein an ambient flow (pure shear, quadratic, and modulated shear)parallel to a close plane wall is considered. Forces and torquesexerted by the ambient flow on a motionless sphere are evaluated.Their precision is determined and related to a multipole orderof the truncation. Similar analysis is performed for a movingsphere with no ambient flow and for a freely moving sphere.Relative motion of the sphere with respect to the wall givesrise to strong lubrication interactions. It is analysed howthese interactions affect accuracy of the pure multipole expansion,and what are the smallest distances where it becomes insufficient.An alternative precise method is applied, in which lubricationexpressions are subtracted from the hydrodynamic forces andtorques, and the residue is evaluated as a fast-convergent seriesof inverse powers of the distance between the sphere centreand the wall. The accuracy of this procedure is carefully analysed. 相似文献