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51.
Sk. Asrof Ali Yunusa Umar B. F. Abu‐Sharkh Hasan A. Al‐Muallem 《Journal of polymer science. Part A, Polymer chemistry》2006,44(19):5480-5494
The cycloterpolymerizations of single‐, twin‐, and triple‐tailed hydrophobes with hydrophilic monomer N,N‐diallyl‐N‐carboethoxymethylammonium chloride and sulfur dioxide afforded a series of cationic polyelectrolytes (CPEs) in excellent yields. These CPEs, upon the acidic hydrolysis of the pendent ester groups, gave the corresponding pH‐responsive cationic acid salts, which, upon a treatment with sodium hydroxide, were converted to polybetaines (PBs), anionic polyelectrolytes (APEs), and PB/APE polymers containing various proportions of zwitterionic (PB) and anionic fractions (APE) in the polymer chain. At a shear rate of 0.36 s−1 at 30 °C, salt‐free water solutions of the CPEs (2 g/dL) containing 8, 4, and 2.67 mol % of the single‐, twin‐, and triple‐tailed hydrophobes (all having 8 mol % octyloxy tails) had apparent viscosity values of 70, 2800, and 396,000 cps, respectively. The PB/APE polymer with a ratio of 33:67 for the zwitterionic and anionic fractions in the polymer chain gave the highest viscosity value. The superior viscosity behavior of the polymers containing the triple‐tailed hydrophobe was attributed to the blocky nature of the comonomer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5480–5494, 2006 相似文献
52.
G. N. Al’tshuler A. A. Evdoshenko E. V. Ostapova 《Russian Journal of Applied Chemistry》2006,79(1):79-81
Conductivity of the network polymer based on tetra(sulfonatophenyl)-meta-cyclophanoctol in the H+, Na+, Cu2+, Zn2+, and Ni2+ forms is studied, and the self-diffusion coefficients and activation energies of diffusion of the metal cations in the polymer phase are estimated. 相似文献
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57.
L. Adiels G. Backenstoss I. Bergström S. Carius S. Charalambous M. D. Cooper Ch. Findeisen D. Hatzifotiadou M. Hugi A. Kerek H. O. Meyer P. Pavlopoulos J. Repond L. Tauscher D. Troester M. C. S. Williams K. Zioutas 《Zeitschrift fur Physik C Particles and Fields》1989,42(1):49-58
The inclusive η-momentum spectrum from \(\bar p\) annihilations at rest in liquid hydrogen was measured at LEAR. Branching ratios were obtained for $$\begin{gathered} p\bar p \to \eta \omega \left( {1.04_{ - 0.10}^{ + 0.09} } \right)\% ,\eta \rho ^0 \left( {0.53_{ - 0.08}^{ + 0.20} } \right)\% , \hfill \\ \pi a_2 \left( {8.49_{ - 1.10}^{ + 1.05} } \right)\% ,\eta \pi ^0 \left( {1.33 \pm 0.27} \right) \times 10^{ - 4} , \hfill \\ \end{gathered} $$ , and ηη(8.1±3.1)×10?5. An upper limit for \(p\bar p \to \eta \eta '\) of 1.8×10?4 at 95% CL was found. The ratio of the branching ratios is BR(η?)/BR(ηω)=0.51 ?0.06 +0.20 . For the ratio of branching ratios into two pseudoscalar mesons, we have BR(ηπ0)/BR(π0π0)=0.65±0.14, BR(ηη)/BR(π0π0), BR(η η ′ )/BR(π0π0) at 95% CL, and BR(ηη)/BR(ηπ0). 相似文献
58.
Rolf Källström 《Communications in Mathematical Physics》1989,126(1):157-166
In this paper we consider distributions of the form 1/P and dy/P(x,y), whereP is a polynomial. Using results by Kashiwara and Kawai we give fairly accessible proofs that these expressions can be defined as regular holonomic distributions by utilising a meromorphic parameter. We also discuss distributions of the form /P and their direct image
, when one knows that is a regular holonomic distribution. All these distributions are relevant to the study of renormalised Feynman integrals. 相似文献
59.
The strain energies and through-space distances between the two bridgehead E atoms of a selection of 1,3-dimethyl-1,3-ditetrelbicyclo[1.1.1]pentanes
(tetrel E = Si, Ge or Sn) were examined by quantum chemical calculations at MP2 and B3LYP levels. The aim is to identify which
bridges lead to short through-space E,E distances, and simultaneously, to as low strain as possible. A short E,E distance
should improve through-space interaction, and a low strain should promote the thermal stability and possibly also facilitate
their synthesis. The bridges examined included CH2, CMe2, CtBu2, C(CH2)n (n = 2–4), O, NMe, S, PMe, SiMe2, GeMe2, and SnMe2. The calculations indicate that the phospha bridge is a good compromise providing reasonably low strain as well as E,E through-space
distances which are only longer than normal E–E single bonds by factors of 1.06–1.10.
This paper is dedicated to Professor Mitsuo Kira in recognition of his stimulating Si chemistry and his 2005 Wacker Award. 相似文献
60.
Margareta H. Häggström Charles L. Cooney 《Applied biochemistry and biotechnology》1984,9(5-6):475-481
Glucose prevents maltose utilization bySaccharomyces cerevisiae in batch culture, whereas in a mixed carbohydrate-limited chemostat, maltose and glucose were consumed simultaneously. The specific activity of α-glucosidase was dependent on the dilution rate as well as the proportion of maltose in the mixture. Maximum specific activities in the batch and chemostat cultures on mixtures of maltose and glucose were lower than corresponding values observed on maltose alone. 相似文献