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51.
V. N. Lopatin A. D. Aponasenko N. V. Shepelevich 《Journal of Applied Spectroscopy》1997,64(6):825-831
We investigate the possibilities of creating a method for estimating the optical constants, dimensions, and concentrations
of “soft” absorbing particles by applying a theoretical analysis of the angular dependence of the intergrated indicatrix,
overall characteristics of light scattering, and absorption on the phase shift and diffraction parameter of particles in the
brightening band region. We show that using the investigated optical characteristics, it is possible to determine the unknown
parameters of a suspension from experimental data.
Institute of Biophysics, Siberian Branch of the Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russia. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 807–812, November–December, 1997. 相似文献
52.
A. M. Popov 《Mathematical Notes》1998,64(3):377-381
For operators corresponding to systems ofμth-order difference-differential equations of neutral type, necessary and sufficient conditions for potentiality with respect
to the classical bilinear form are obtained. These results are applied to first-order quasilinear systems.
Translated fromMatematicheskie Zametki, Vol. 64, No. 3, pp. 437–442, September, 1998.
The author wishes to express his thanks to V. M. Savchin for fruitful discussions and useful remarks. 相似文献
53.
K. Naito 《Journal of Optimization Theory and Applications》1989,60(1):57-65
We treat an abstract semilinear control system and study the controllability problem for its trajectories. Assuming a range condition of the control action operator and an inequality condition on the system parameters, we can show that the reachable trajectory set of the semilinear system is equivalent to that of its corresponding linear system.The author wishes to express his deep appreciation to Prof. T. I. Seidman for his many helpful suggestions and to Prof. W. Takahashi for many stimulating conversations. 相似文献
54.
Summary Complete Active-Space Self-Consistent-Field (CAS-SCF) calculations for cubic N8 are presented. We studied the N8↔4N2 reaction inD
4h
symmetry and found its energy release and activation barrier with three different atomic basis sets. The energy release for
this reaction is predicted to be around 526 kcal/mol, while the energy barrier to dissociation is estimated about 159 kcal/mol.
These results are in substantial agreement with previousab initio estimates.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
55.
J. P. Wesley 《Foundations of Physics Letters》1990,3(6):581-605
Weber electrodynamics predicts the Kaufmann-Bucherer experiments and the fine structure energy level splitting of the H-atom (neglecting spin) without mass change with velocity (i.e., mass
). The Weber potential for the gravitational case yields Newtonian mechanics, confirming Mach's principle. It provides a cosmological condition yielding an estimated radius of the universe of 8 × 109 light years. Despite these successes, the independent evidence for Kaufmann mechanics, where mass changes with velocity (i.e., mass
) is convincing. Perhaps a slight alteration may make the Weber theory compatible with Kaufmann mechanics. 相似文献
56.
57.
聚苯乙烯型双季铵树脂的制备及性能研究 总被引:3,自引:0,他引:3
三乙烯二胺和四甲基乙二胺与氯甲基聚苯乙烯反应,得到同时含有季铵和叔胺的强-弱碱型树脂,再用碘甲烷季铵化叔胺,制备聚苯乙烯双季铵树脂;另一种方法是将二甲基苄胺型叔胺树脂用4-溴丁基三甲基溴化铵季铵化引入4碳链双季铵基团。反应结果表明,两类强弱碱基树脂的季铵化反应结果并不理想,二甲基苄胺型叔胺树脂季铵化反应的转化率最高为36%。考察了这些新型双季铵树脂的热稳定性及对水溶液中有机酸(如苯磺酸和对-硝基苯乙酸)的吸附、脱附性能。 相似文献
58.
I. A. Machkarovskaya K. Ya. Burshtein V. A. Petrosyan 《Russian Chemical Bulletin》1995,44(11):2053-2059
A series ofS
N2 reactions with halomethanes as substrates and the corresponding anions as nucleophiles were studied by the semiempirical MNDO and AM1 methods, taking into account solvent effects. Analysis of the kinetics, structures of reagents, intermediates and products, and charge distribution in them allows one to draw the conclusion that the retardation ofS
N2 reactions is stronger in solvents than in the gas phase, and the rates of reactions involving anions with a lower number of halogen atoms are higher.For Part 8 see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2148–2154, November, 1995.This work was partially financially supported by the International Science Foundation (Grant No. MHYOO). 相似文献
59.
毛细管电泳-质谱联用法测定性保健品中的脱水吗啡和西地那非 总被引:10,自引:0,他引:10
脱水吗啡和西地那非是目前治疗男性性功能障碍的常用药物,在临床上已广泛应用。但最近的研究表明,当服用西地那非剂量较大时会引起头痛、消化不良、头晕、皮疹等不良反应。更为严重的是,西地那非能增强硝酸酯类药物的降压能力,与硝酸酯类药物同时使用时,可能会引起致命性低血压 相似文献
60.
Fibers and 3D mesh scaffolds from biodegradable starch-based blends: production and characterization
The aim of this work is the production of fibers from biodegradable polymers to obtain 3D scaffolds for tissue engineering of hard tissues. The scaffolds required for this highly demanding application need to have, as well as the biological and mechanical characteristics, a high degree of porosity with suitable dimensions for cell seeding and proliferation. Furthermore, the open cell porosity should have adequate interconnectivity for a continuous flow of nutrients and outflow of cell metabolic residues as well as to allow cell growth into confluent layers. Blends of corn starch, a natural biodegradable polymer, with other synthetic polymers (poly(ethylene vinyl alcohol), poly(epsilon-caprolactone), poly(lactic acid)) were selected for this work because of their good balance of properties, namely biocompatibility, processability and mechanical properties. Melt spinning was used to produce fibers from all the blends and 3D meshes from one of the starch-poly(lactic acid) blends. The experimental characterization included the evaluation of the tensile mechanical properties and thermal properties of the fibers and the compression stiffness, porosity and degradation behavior of the 3D meshes. Light microscopy picture of 3D meshes. 相似文献