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81.
Clouding behaviour in surfactant systems 总被引:1,自引:0,他引:1
Mukherjee P Padhan SK Dash S Patel S Mishra BK 《Advances in colloid and interface science》2011,162(1-2):59-79
A study on the phenomenon of clouding and the applications of cloud point technology has been thoroughly discussed. The phase behaviour of clouding and various methods adopted for the determination of cloud point of various surfactant systems have been elucidated. The systems containing anionic, cationic, nonionic surfactants as well as microemulsions have been reviewed with respect to their clouding phenomena and the effects of structural variation in the surfactant systems have been incorporated. Additives of various natures control the clouding of surfactants. Electrolytes, nonelectrolytes, organic substances as well as ionic surfactants, when present in the surfactant solutions, play a major role in the clouding phenomena. The review includes the morphological study of clouds and their applications in the extraction of trace inorganic, organic materials as well as pesticides and protein substrates from different sources. 相似文献
82.
A cationic gold carbonyl complex has been synthesized and characterized using several techniques including X-ray crystallography. [(Mes(3)P)Au(CO)][SbF(6)] (Mes = 2,4,6-Me(3)C(6)H(2)) has a linear, two-coordinate gold atom. This compound displays the CO stretching frequency at 2185 cm(-1). The (13)C NMR signal of the gold-bound (13)CO appears as a doublet centered at δ 182.6 ((2)J(C,P) = 115 Hz). A computational study shows that the Au-CO bond consists of electrostatic attraction, Au ← CO donation, and significant Au → CO π-back-bonding components. Polarization of the CO bond caused by the electrostatic effect of the cationic gold center is mainly responsible for the large blue shift in the CO stretching frequency. 相似文献
83.
Background
The extent of similarity between consolidation and reconsolidation is not yet fully understood. One of the differences noted is that not every brain region involved in consolidation exhibits reconsolidation. In trace fear conditioning, the hippocampus and the medial prefrontal cortex (mPFC) are required for consolidation of long-term memory. We have previously demonstrated that trace fear memory is susceptible to infusion of the protein synthesis inhibitor anisomycin into the hippocampus following recall. In the present study, we examine whether protein synthesis inhibition in the mPFC following recall similarly results in the observation of reconsolidation of trace fear memory. 相似文献84.
Pierre Bonami Gérard Cornuéjols Sanjeeb Dash Matteo Fischetti Andrea Lodi 《Mathematical Programming》2008,113(2):241-257
Recent experiments by Fischetti and Lodi show that the first Chvátal closure of a pure integer linear program (ILP) often
gives a surprisingly tight approximation of the integer hull. They optimize over the first Chvátal closure by modeling the
Chvátal–Gomory (CG) separation problem as a mixed integer linear program (MILP) which is then solved by a general- purpose
MILP solver. Unfortunately, this approach does not extend immediately to the Gomory mixed integer (GMI) closure of an MILP,
since the GMI separation problem involves the solution of a nonlinear mixed integer program or a parametric MILP. In this
paper we introduce a projected version of the CG cuts, and study their practical effectiveness for MILP problems. The idea
is to project first the linear programming relaxation of the MILP at hand onto the space of the integer variables, and then
to derive Chvátal–Gomory cuts for the projected polyhedron. Though theoretically dominated by GMI cuts, projected CG cuts
have the advantage of producing a separation model very similar to the one introduced by Fischetti and Lodi, which can typically
be solved in a reasonable amount of computing time.
Gérard Cornuéjols was supported in part by NSF grant DMI-0352885, ONR grant N00014-03-1-0188, and ANR grant BLAN 06-1-138894.
Matteo Fischetti was supported in part by the EU projects ADONET (contract n. MRTN-CT-2003-504438) and ARRIVAL (contract n.
FP6-021235-2). Andrea Lodi was supported in part by the EU projects ADONET (contract n. MRTN-CT-2003-504438) and ARRIVAL (contract
n. FP6-021235-2). 相似文献
85.
Summary Cobaloxime complexes containing the biologically active ligand imidazole and poorly coordinating anions, such as ClO
4
–
or BF
4
–
, have been synthesised. The perchlorate anion is not involved in coordination and there is evidence that [Co(DH)2(L)2]ClO4 complexes are formed, whereas the tetrafluoroborate anion is involved in weak coordination giving complexes of the type [Co(DH)2(L)(BF4)] in the solid state. However, solvolysis of these latter complexes in solution yields 11 electrolytic species. The i.r. and electronic spectra, magnetic and conductivity measurements in nonaqueous media have been employed to characterise the complexes.Ligand abbreviations Py
pyridine
- Im
imidazole
- Me
methyl
- Al
allyl
- Vi
vinyl 相似文献
86.
Summary A series of manganese(II) spin-free complexes of the type: MnLn Cl2 [L =N-Methylimidazole (MeIm), n = 1,2,3,6; L =N-ethylimidazole (EtIm), n = 4], MnLnBr2 (L = MeIm, n = 2, 4, 6; L = EtIm, n = 4, 6), MnLnI2 (L = MeIm, n = 4, 6; L = EtIm, n = 6), MnLn(NCS)2 (L = MeIm, n = 3, 4; L = EtIm, n = 4), MnL6X2 (L = MeIm, EtIm; X = NO3, ClO4, BF4); (Me4N)(MnLCl3)(L = MeIm, EtIm); (Et4N)[Mn(MeIm)Br3] and Mn(MeIm)2(N3)2 · 5 H2O were prepared and characterized. The complexes have either octahedral, distorted octahedral, polymeric octahedral or tetrahedral structures. 相似文献
87.
A procedure for calculating critical exponents directly at finite ? is proposed. It relies on the invariance of the critical exponents at the critical coupling gc of the full theory with respect to finite changes in the renormalization point. This is expressed as the coincidence of curves at the point β = 0 in the plane of β versus a critical exponent parametrically described by the renormalized coupling for various values of the renormalization point (the “twisted fan”). If more than one critical exponent is present the fan is a set of curves in a multidimensional space with the twist at β = 0 and the exact values of the critical exponents. In perturbative approximations, an approximate invariance may result whether or not a zero of β exists to that order. We show that in the one and two loop approximations to the Reggeon calculus this approximate invariance does occur. The values of the critical exponents at the approximate twists show remarkable stability properties. We obtain σtot ≈ (lns)?γ where ?γ ≈ 0.11 and 0.17 for one and two loops respectively. 相似文献
88.
We apply the technique known in solid state physics as the n-loop expansion to calculate the critical indices of the φ3 Gribov Reggeon calculus directly in two transverse dimensions. Infrared pathologies of the massless theory require the calculation to be done in the infinite momentum limit of the massive theory. For n = 1 the results are close to those of the ε-expansion in O(ε). For n = 2 the β function has no zero, analogously to the case in solid state physics. Use of a Padé approximant for β yields σtot ≈ (1n s)0.27 at infinity, close to the O(ε2) result. 相似文献
89.
Chitta R. Panda Vivekananda Chakravortty Kailash C. Dash 《Transition Metal Chemistry》1988,13(4):287-290
Summary Interaction of ZrOCl2:8H2O, [Zr4(OH)8(H2O)16]Cl8 12H2O, with the heterocyclic, aldimines (PyAlA) and heterocyclic ketimines (AcPyA) in Me2CO in the presence of HC(OEt)3 yields white amorphous compounds of the type [Zr4(OH)12(H2O)8(PyAlA)2]Cl4 and [Zr4(OH)12(H2O)10(AcPyA)]Cl4. Presumably these compounds have a tetrameric dodecahedral structure, derived from the parent. The analytical data, i.r., electrical conductance and t.g. measurements all favour the tetrameric formulation. The t.g. studies also indicate the intermediacy of complex species, which lose water and the Schiff base ligands, with increase in temperature. 相似文献
90.
We calculate the ratios of πp, Kp and ψp total cross sections utilizing coupled homogeneous linear integral equations supplemented with SU(4) symmetry for the couplings. Kinematic effects arising from mass splitting and tmin effects are crucial. We obtain . 相似文献