Stability properties of cycles and tori of a simplest nonresonant wave-type equation

For a number of meaningful examples, nonresonant wave-type equations are shown to be characterized by periodic dynamics. Translated fromMatematicheskie Zametki, Vol. 62, No. 5, pp. 744–750, November, 1997. Translated by O. V. Sipacheva     

Fast intramolecular dynamics of triphenyl phosphite investigated by <Emphasis Type="Bold">2</Emphasis>H NMR

The first analysis of rapid intramolecular motions of triphenyl phosphite by ²H NMR is presented. The fragile slowing down of the primary relaxation is followed by a solid-echo method. The occurrence of a fast reorientation of the phenyl side groups is demonstrated in the supercooled liquid state, identified as a two-fold flip on the basis of simple lineshape simulations. Coexistence of both static and motionally averaged components in “two phase” spectra indicate a broad distribution of correlation times for this relaxation. This dynamical behavior is shown to persist in the glacial phase. Received 28 May 2002 / Received in final form 1st October 2002 Published online 31 December 2002     

Effect of frequency on sonochemical reactions. I: Oxidation of iodide

The effect of continuous sonication on the kinetics of iodine formation in aqueous iodide solutions was studied in the presence of air and argon at two frequencies, 20 and 900 kHz. Most workers in this area assume that frequency has a negligible effect on sonochemical reactions. The present results indicate, however, that there is a significant effect in the above solutions. The rate of sonochemical oxidation of iodide in aqueous solution is 3.1 times greater in presence of air than argon at 900 kHz, in contrast to the situation at 20 kHz, where the ratio is 0.9 A 900 kHz apparatus was specially designed to make it possible to measure the absolute acoustic power delivered into the solution. The rate of oxidation per unit power in this new 900 kHz apparatus can be more than 30 times greater than that at 20 kHz for the oxidation of iodide in the presence of air.     

LD泵浦Nd:YAG微片激光器

ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器结构简单紧凑，与半导体激光器相比，前者具有激光线宽窄、光束质量好、相干长度长等优点，因此在一些测量领域有着较好的应用前景。目前对ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的实验工作主要是获得单频、单模连续输出和线性频率调制特性研究。本文综述了近几年来ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的研究方向、成果及应用，主要介绍了各国对ＬＤ泵浦Ｎｄ：ＹＡＧ微片激光器的调频特性的研究状况     

Locally resolved photothermally modulated ferromagnetic resonance on epitaxial Fe-films deposited on laterally patterned GaAs

(0 0 1)Fe-mesa were grown on a GaAs high electron mobility transistor (HEMT)-structure. Magnetic properties were investigated by locally resolved photothermally modulated ferromagnetic resonance (PM-FMR). The surface and the in-plane anisotropy are decreased in HEMT-areas. The field independent response of PM-FMR provides information on the electrical properties of the GaAs-heterostructure and yields evidence of preparation dependent lifetime effects of the photo-carriers.     

Search for narrow NNπ resonances in exclusive pp→ppππ measurements

Narrow structures in the range of a few MeV have been searched for in ppπ⁺ and ppπ⁻ invariant mass spectra (M_ppπ⁺ and M_ppπ⁻) obtained from exclusive measurements of the pp→ppπ⁺π⁻ reaction at T_p=725,750 and 775 MeV using the PROMICE/WASA detector at CELSIUS. The selected reaction is particularly well suited for the search for dibaryon resonances decoupled from NN and/or NΔ. In the mass range 2020 MeV/c²<m_dibaryon<2085 MeV/c² no narrow structures could be identified on the 3σ level of statistical significance neither in M_ppπ⁻ nor in M_ppπ⁺ giving an upper limit (95% C.L.) for dibaryon production in this reaction of σ<20 nb.     

一类共振条件下的高阶p-Laplacian算子多点边值问题

主要讨论了下列n阶带p-Laplacian算子多点边值问题在共振条件下解的存在性.(Φp(x(n-1)))′+f(t,x,x′,…,x(n-2))=0,0相似文献   

Angular Distribution of Hyperfine Magnetic Field in Fe3O4 and Fe66Ni34 from Mössbauer Polarimetry

Nuclear resonance studies of the two different types impurity doped potassium hexachloro-stannates, the isomorphic system such as (K–Rb)₂SnCl₆ and K₂(Sn–Re)Cl₆ and the nonisomorphic system K₂SnCl₆:Al³⁺ in the high temperature cubic phase revealed contrasting features with one the other characterized by static in the former and dynamic feature in the latter case respectively. The resonance spectra of the nonisomorphic system indicate additionally a sign of the local structural transition above the conventional structural phase transition temperature. This seems to be triggered by the ligand-deficient octahedral defects and can be explained in terms of the enhanced activity of the octahedral defects for the hindered rotation.     

Characterization,solution properties,and morphologies of a hydrophobically associating cationic terpolymer

The acrylamide‐based terpolymers (PADB) with 4‐butylstyrene (BST) as the hydrophobic monomer and dimethyldiallyammonium chloride (DMDAAC) were synthesized by the micellar free radical technique. The polymer was determined by UV, FT‐IR and ¹HNMR, and the hydrophobic microblock structure of PADB was characterized successfully by the conventional DSC measurement. The use of DMDAAC improves the water solubility and intermolecular association of terpolymers. The feed amount of BST affects greatly the apparent viscosity of PADB solution. The polymer exhibits good viscosification property, salt resistance, temperature‐thickening, thixotropy, pseudoplastic behavior and shear‐thickening at low shear rate. The apparent viscosities of PADB solution remarkably increase by the addition of a small amount of surfactant. AFM measurements show that hydrophobic aggregates have been formed in 0.1 g dL^?1 PADB aqueous solution, indicative of strong associations of hydrophobic groups, which are reinforced with increasing PADB concentration. The microstructures of PADB are disrupted by the addition of small amounts of salt, resulting in the decrease in solution viscosity. However, with increasing NaCl concentration, the tree‐like associating structures are formed, leading to the increase in the solution viscosity of PADB. The AFM results reveal that the solution properties of PADB are due to the associating structures in the aqueous solution and brine solution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 826–839, 2007