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1.
Summary The cationic polymerization of 2-ethyl-2-oxazoline using CH3I as initiator at different monomer/initiator ratios, temperatures, solvents and times of polymerization was carried out. The effect of these variables on the polymerization yield and viscosity of the polymers was studied. The poly(N-propionyl)iminoethylene was hydrolyzed in acid medium obtaining a linear poly(ethyleneimine) (PEI). All the polymers were characterized by elemental analysis, IR,1H NMR, and13C NMR spectroscopy. 相似文献
2.
Anju Sawada Takehiro Kubo Yosikazu Abe Kazuyuki Matsumoto 《Journal of Low Temperature Physics》1995,101(3-4):707-712
The isochoric pressure of bcc Solid3He in the vicinity of the triple point has been measured by changing the temperature stepwisely and waiting for thermal equilibrium. We observed anomalous pressure kinks of the temperature dependence in the paramagnetic region near the triple point. This anomaly appeared at 0.37 to 0.40 tesla, and disappeared below 0.36 tesla. Moreover, critical phenomena at the transition point from the paramagnetic phase (PP) to the high field phase was observed and the phase line curves toward the PP side. 相似文献
3.
Catalysts Pt/SiO2 with different size of Pt nanoaggregates were studied in catalytic reduction of U(VI) with hydrazine in solutions of H2SO4, HClO4, and HNO3. The catalytic activity of the surface Pt atoms of Pt/SiO2 in this reaction monotonically increases with an increase in the size of metal crystallites on the support, i.e., the negative size effect is observed. Catalytic reduction of U(VI) with hydrazine in H2SO4 solutions is significantly faster than in HClO4 and HNO3, and in HClO4 it is slightly faster than in HNO3. The results were interpreted within the framework of the concept of the energetic nonuniformity of the surface atoms and of the mechanisms of catalytic reduction of U(VI) with hydrazine in acid solutions. 相似文献
4.
B. I. Anan’ev 《Journal of Computer and Systems Sciences International》2007,46(3):391-398
The problems of constructing recursive relations for conditional and unconditional distributions of random informational sets are considered. These sets, which are called multi-estimates in the paper, appear naturally in the problems of estimation of states and parameters of multistage stochastic inclusions. 相似文献
5.
M. S. Anan’evskii 《Automation and Remote Control》2007,68(8):1322-1332
A new approach to synthesize algorithms for selective control of the observables in quantum mechanical systems in the presence of additional constraints during the whole period of control is proposed. Analytic results of achieving the goal of control under some additional assumptions were obtained. It was demonstrated that the error in achieving the goal of control is proportionate to the error in prescribing the initial state of system and the error in realizing the control action. Numerical results for the problem of selective control for energy of hydrogen molecules (H2) with different isotopes are represented. The proposed algorithms are easy to design. 相似文献
6.
7.
Materials made from yttrium silicates were synthesized by the sol-gel method. The effect of the amount of yttrium oxide, which
varied from 10 to 50% (molar content), and the water:alcoholate molar ratio was investigated. Structure formation and the
character of crystallization of gels in heat treatment in the 650–1300°C range were investigated.
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Translated from Steklo i Keramika, No. 1, pp. 3–6, January, 2007. 相似文献
8.
S. V. Zavarzin A. V. Anan’ev A. I. Fadeev M. Yu. Kalenova I. V. Kuznetsov 《Radiochemistry》2017,59(5):448-452
Electrochemical properties of the intermetallic compound URh3 in 0.5–8 M HNO3 solutions were studied by linear voltammetry. The electrochemical characteristics of URh3 in nitric acid solution were determined for the first time using the Tafel equation. URh3 is highly resistant to both chemical and anodic dissolution, which is due to formation of passive films on the electrode surface. All the anodic oxidation processes observed on the electrode led to secondary passivation of the alloy and not to its dissolution. The conclusions based on the electrochemical data were confirmed by experiments in 8 M HNO3. 相似文献
9.
For a linear controllable system, the problem of reconstruction of all input signals, which are compatible with the measured signal, is considered. It is assumed that information can be transmitted in a processing center only via digital communication channel at discrete time instants, and the word length is limited. In this connection, there are encoding and decoding devices in the communication channel. For simplicity, the communication channel is assumed to be noiseless and delay-free. Defining relationships are obtained for the set of compatible input signals, as well as relationships between reconstruction precision, length of transmitted word and transmission frequency. 相似文献
10.
The beam-slab layout design task is an ill-defined problem. As a result, it is difficult to delegate this task to computers. This study proposes a new genetic algorithm to be used to perform this design task. First, a new coding scheme for beam-slab layouts is developed. After that, the beam-slab layout design problem is written as an optimization problem by establishing proper objective and constraint functions. To show the validity of the proposed algorithm, it is used to design beam-slab layouts of several floor plans. The obtained results show that the proposed technique is able to find good beam-slab layouts. 相似文献