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651.
Alcohol ethoxylates (AEs) and alkylamine ethoxylates (AMEs) are used as adjuvants in pesticide formulations. Analytical procedures for these compounds in environmental aqueous samples using LC-MS are presented. Sample preparation uses solid-phase extraction with Porapak Rdx cartridges. Detection limits and recoveries in ground water and surface water are, respectively, AEs: 16-60 ng/l, 35-93% and AMEs: 0.3-6 microg/l, 28-96%. The lower recoveries are obtained for the apolar surfactants. The procedure was employed on samples of ground water and soil interstitial water collected from farming areas. The individual AEs were detected at concentration levels ranging from 33 to 189 ng/l water. 相似文献
652.
S. Ole Warnaar 《Journal of statistical physics》1996,82(3-4):657-685
The problem of computing the one-dimensional configuration sums of the ABF model in regime III is mapped onto the problem of evaluating the grandcanonical partition function of a gas of charged particles obeying certain fermionic exclusion rules. We thus obtain a newfermionic method to compute the local height probabilities of the model. Combined with the originalbosonic approach of Andrews, Baxter, and Forrester, we obtain a new proof of (some of) Melzer's polynomial identities. In the infinite limit these identities yield Rogers-Ramanujan type identities for the Virasoro characters
l,1
(r–l,r)
(q) as conjectured by the Stony Brook group. As a result of our work the corner transfer matrix and thermodynamic Bethe Ansatz approaches to solvable lattice models are unified. 相似文献
653.
Afshar’s Experiment Does Not Show a Violation of Complementarity 总被引:1,自引:1,他引:0
Ole Steuernagel 《Foundations of Physics》2007,37(9):1370-1385
A recent experiment performed by S. Afshar [first reported by M. Chown, New Sci. 183:30, 2004] is analyzed. It was claimed that this experiment could be interpreted as a demonstration of a violation of the principle
of complementarity in quantum mechanics. Instead, it is shown here that it can be understood in terms of classical wave optics
and the standard interpretation of quantum mechanics. Its performance is quantified and it is concluded that the experiment
is suboptimal in the sense that it does not fully exhaust the limits imposed by quantum mechanics. 相似文献
654.
The conditions of the appearance of in-phase oscillations in the time dependences of the low-frequency internal friction and effective shear modulus G eff in Al-0.01 wt% Cu and Al-0.001 wt % Cu alloys are studied. The in-phase oscillations are shown to appear in the alloys only when their dislocation-impurity structure is disturbed from equilibrium and the impurity concentration near a dislocation is optimum. This fact suggests that the in-phase oscillations are due to a collective character of dislocation-impurity interactions, which leads to a transfer of energy of translational dislocation motion to transverse dislocation vibrations in the main slip plane. 相似文献
655.
The Bailey transform and false theta functions 总被引:1,自引:0,他引:1
An empirical exploration of five of Ramanujan's intriguing false theta function identities leads to unexpected instances of
Bailey's transform which, in turn, lead to many new identities for both false and partial theta functions.
2000 Mathematics Subject Classification Primary—33D15, 11P83
Partially supported by National Science Foundation Grant DMS 0457003.
Supported by the Australian Research Council. 相似文献
656.
Qian Huang Marc Mangnus Nicolas J. Alvarez Rudy Koopmans Ole Hassager 《Rheologica Acta》2016,55(5):343-350
The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU-FSR) and a commercial filament stretching rheometer (VADER-1000). We show that the measurements from the EVF are limited by a maximum Hencky strain of 4, while the two filament stretching rheometers are able to probe the nonlinear behavior at larger Hencky strain values where the steady state is reached. With the capability of the filament stretching rheometers, we show that LDPEs with quite different linear viscoelastic properties can have very similar steady extensional viscosity. This points to the potential for independently controlling shear and extensional rheology in certain rate ranges. 相似文献
657.
Lai WC McLean N Gansmüller A Verhoeven MA Antonioli GC Carravetta M Duma L Bovee-Geurts PH Johannessen OG de Groot HJ Lugtenburg J Emsley L Brown SP Brown RC DeGrip WJ Levitt MH 《Journal of the American Chemical Society》2006,128(12):3878-3879
A new double-quantum solid-state NMR pulse sequence is presented and used to measure one-bond 13C-13C J-couplings in a set of 13C2-labeled rhodopsin isotopomers. The measured J-couplings reveal a perturbation of the electronic structure at the terminus of the conjugated chain but show no evidence for protein-induced electronic perturbation near the C11-C12 isomerization site. This work establishes NMR methodology for measuring accurate 1JCC values in noncrystalline macromolecules and shows that the measured J-couplings may reveal local electronic perturbations of mechanistic significance. 相似文献
658.
Tompsett GA Krogh L Griffin DW Conner WC 《Langmuir : the ACS journal of surfaces and colloids》2005,21(18):8214-8225
Sorption hysteresis is a widely studied phenomenon whose predicted behavior is well documented and researched. On the other hand, there is much less known about the region that lies between sorption isotherms, believed to be a metastable region. Scanning curves are a way of understanding the mechanism of hysteresis and a tool for hysteresis model validation. Scanning curves were produced for mesoporous materials: SBA-15 and MCM-41 for N(2) sorption at 77 K and Ar sorption at 87 K. A limited set of different scanning behaviors is identified. Like most hysteresis theories, it was found that a single model for scanning behavior cannot be extended to all materials under the same or different experimental conditions. Two behaviors are consistent with recent theories and simulations; however, several are not. The implications as to the characterization of pore dimensions and structure are discussed. 相似文献
659.
Gautier R Andersen OK Gougeon P Halet JF Canadell E Martin JD 《Inorganic chemistry》2002,41(18):4689-4699
Magnetic and electrical resistivity properties of RMo(8)O(14) (R = La, Ce, Pr, Nd, Sm) compounds containing different bicapped-octahedral Mo(8) clusters are discussed. Extended Hückel (EH) molecular calculations were carried out in order to study the influence of the position of metal capping atoms on the electronic structure of different Mo(8) isomers. Different optimal metal electron counts are possible for these clusters. Periodic density functional calculations confirm the molecular character of these compounds and allow the understanding of their semiconducting and magnetic properties. 相似文献
660.
Schulte-Herbrüggen T Meissner A Papanikos A Meldal M Sørensen OW 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2002,156(2):282-294
The MBOB, broadband HMBC, and broadband XLOC NMR pulse sequences (A. Meissner and O. W. S?rensen (2000, Magn. Reson. Chem. 38, 981-984; 2001, 39, 49-52)) were introduced as a means of obtaining heteronuclear long-range correlation spectra with broadband excitation over an interval of heteronuclear long-range J coupling constants. However, it is not trivial what combination of delays to choose for a given purpose, particularly if one-bond and long-range correlation spectra are obtained simultaneously as in MBOB. This paper presents a way to determine sets of delays for MBOB, broadband HMBC, and broadband XLOC resolving the problem. The results tabulated suit various ranges of J coupling constants and transverse relaxation times. 相似文献