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91.
92.
Georgios Patias Ioannis Choinopoulos Spyros Koinis Marinos Pitsikalis 《Journal of polymer science. Part A, Polymer chemistry》2018,56(19):2192-2202
Seven (half-)titanocene alkoxide complexes, [Cp2TiCl(OEt)], [Cp2TiCl(O-2-Bu)], [Cp2TiCl(OCH2CF2CF2H)], [CpTiCl2(OEt)], [CpTiCl2(O-(S)-2-Bu)], [CpTiCl2(OCH2CF3)], and [Cp2TiCl(OCH2CF3)], were synthesized and employed in lactide coordination polymerization. These organotitanium (IV) compounds proved to be very efficient initiators for the ring-opening polymerization of enantiomeric l -lactide and racemic mixture of rac-lactide, leading to end-functionalized polymers. Kinetic studies illustrated that these compounds produce well-defined polymers in a controlled manner. This was further demonstrated by synthesizing poly(l -lactide-b-hexyl isocyanate) diblock copolymer. The effect of the alkoxy end groups on the thermal behavior of the polymers was also studied by thermogravimetric analysis and differential scanning calorimetry. The polymers were characterized using size exclusion chromatography and proton nuclear magnetic resonance spectroscopy. The optical properties of the diblock copolymer were also investigated. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2192–2202 相似文献
93.
Sunitha V. Kumar A. Kishore Shankaraiah P. Jalapathi P. Lincoln Ch. A. 《Russian Journal of General Chemistry》2018,88(7):1515-1524
Russian Journal of General Chemistry - A series of novel benzofuran-1,2,3-triazole hybrid molecules are synthesized using the click chemistry approach. Structures of the synthesized compounds were... 相似文献
94.
Several definitions of the pressure are introduced for one-component systems and shown to be nonequivalent in the presence of a rigid neutralizing background. Relations between these pressures are derived for finite and infinite systems; these relations depend on the asymptotic behavior of the force at infinity, with the Coulomb force at the borderline between different properties. It is argued that only one of those definitions is physically acceptable and its properties are discussed in relation to the asymptotic behavior of the force. It is seen in particular that a knowledge of the state of the infinite system is not sufficient to determine its thermodynamic properties. The results are illustrated by some typical examples.For example, for two-dimensional systems with three-dimensional Coulomb interaction see refs. 2–4. 相似文献
95.
E. Nolte G. Korschinek Ch. Setzensack 《Zeitschrift für Physik A Hadrons and Nuclei》1982,309(1):33-40
The reaction58Ni→96Ru has been investigated withγ spectroscopic methods and pulsed-beam techniques. A level scheme of the magic nucleus152Yb has been established. The half-life of the isomeric 10+ state was found to be 39±5 μs. The result is discussed in the frame-work of the seniority scheme. Theory and experiment show excellent agreement for the half-lives of the 10+ states in theN=82 isotones148Dy,150Er and [152Yb. A level scheme of151Tm, consisting of ten excited states, has been established.β-decay schemes of [152Yb (3.2±0.3 s),152Tm(m) (8.0±1.0 s) and151Tm (3.8±0.8 s) have been derived. The logft value of theβ transition152Yb (00)→152Tm (1+) has been determined to be about 3.4. It was found that theft values of the favouredβ transitions 0+→1+ in theβ decays of [148Dy,150Er and152Yb are almost inversely proportional to the numbers of protons out of theh 11/2 subshell. 相似文献
96.
A simple classical model [5] that is based on a blocking of magnetic clusters in a uniaxial anisotropy field explains characteristic properties of magnetization processes of Cu(5–15 at.%) Mn as transition states between the “zero point magnetization” M0 = M(T → OK) and the thermal equilibrium magnetization M∞ = M(t → ∞, T). Further it shows two facts the experimental confirmations of which we report in this paper: (a) a magnetization decrease with increasing temperature in high fields and (b) a superposition rule for the magnetization processes in small fields and at low temperatures. 相似文献
97.
E. J. Ansaldo J. Boyle Ch. Niedermayer G. D. Morris J. H. Brewer C. E. Stronach R. S. Cary 《Zeitschrift für Physik B Condensed Matter》1992,86(3):317-318
Three distinct electronic states were detected for positive muons (+) after implantation into a C60 powder sample. About 40% of the + remained in the bare (diamagnetic) state, essentially an interstitial charged point particle. The rest of the muons were found to thermalize predominantly in two muonium (Mu=+ e–) atomic species. A vacuum Mu state, with hyperfine coupling close to that of free Mu, most likely at the molecular center, and a muonic substituted radical, i.e. a hydrogen-like Mu addition to double bonds on the carbon rings. This opens up a rich subfield of fullerene spectroscopy using muons. 相似文献
98.
P. E. Sulewski E. Bucher N. Stücheli C. S. Oglesby K. Friemelt M. Vögt J. R. Baumann Ch. Kloc 《Applied Physics A: Materials Science & Processing》1992,54(1):79-83
Recently, an anomalously large redshift of the absorption edge with electric field was claimed for -GaSe1–x
S
x
layered crystals. We have studied Bridgman grown -GaSe crystals as well as vapor transport grown -GaS, and 2H-WSe2. While we have observed a shift in the absorption edge for -GaSe similar to that reported in previous work, our results demonstrate that the redshift arises from Joule heating, and is thus temperature induced, rather than intrinsic. For -GaS, much larger resistivities virtually eliminate Joule heating, and our measurements of the electric field induced absorption edge shift yield an estimated upper limit of approximately 0.04 meV · cm/kV for a field of 2.4×103 kV/cm, in good agreement with the theoretical value expected for the Franz-Keldysh effect.Also at University of Konstanz 相似文献
99.
It is known that compliance scheme does not provide simple linear isotopic sum rules in λ?1 similar to the ones in λ in the force constant scheme. The advantage of not having such sum rules in the compliance scheme is discussed in relation to the uniqueness problem of the molecular force field.Incidentally, for the molecules H2O, D2O, and HDO, two quadratic relations in terms of the inverse frequency parameters λ?1 are obtained. These supplement the three obvious product rule relations. 相似文献
100.
N. Chéenne T. Mishonov J.O. Indekeu 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(4):437-444
In this paper, we report on the sharp peak observed in the third harmonic voltage response generated by a bias sinusoidal
current applied to several strips patterned in a YBa2Cu3O
7 - δ
thin film and in two La2-xSrxCuO4 thin films, when the temperature is close to the normal-superconductor transition. The lambda-shaped temperature dependence
of the third harmonic signal on the current characteristics is studied. Several physical mechanisms of third harmonic generation
are examined.
Received 13 November 2002 / Received in final form 21 February 2003 Published online 7 May 2003 相似文献