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61.
62.
The authors present an analysis of the causes of radiation induced complications in 383 patients referred to the Chair of Clinical Radiology from different medical institutions of the country. It was found that under distant gamma therapy, to prevent the development of complications the value of TDF-factor should not exceed 105--110, for the associated radiotherapy--130--140, and that for close focal roentgenotherapy--130--150. In vast majority of patients (95.3%) the complications resulted from surpassing the normal tissue tolerance. To prevent radiation injuries it is suggested to take into consideration the TDF-factor values, while in planning radiotherapy to choose such schedules of irradiation, which preclude any surpassing of the tolerance of normal tissues and organs adjacent to the tumor.  相似文献   
63.
Layers of Au nanoparticles (NPs) were formed in films of yttria stabilized zirconia (YSZ) on fusedquartz substrates by layer-by-layer magnetron deposition with subsequent annealing. The obtained structures were studied by applying high-resolution transmission electron microscopy (TEM) to transverse sections and using optical absorption spectroscopy. TEM studies revealed the formation of Au NPs with a diameter of 2?3 nm concentrated in a thin layer within the YSZ film. The optical absorption spectra of the studied samples exhibited peaks of resonance plasmon absorption in Au NPs with a maximum wavelength of ~650 nm. The dependences of geometric and structural parameters of Au NP arrays (size, density, thickness of the Au NP layer, etc.) on the formation conditions were determined, and the regimes of fabrication of dense Au NP arrays that allow for collective plasmon excitations were identified.  相似文献   
64.
A fundamental thermodynamic model of formation of catalyst clusters for growing carbon nanotubes has been developed and model predictions have been compared with the experimental data. An expression for the size distribution function of clusters, depending on the conditions of their formation, is obtained. It is shown that surface tension plays an important role in the cluster formation. The surface tension coefficient for iron clusters at 950°C is determined.  相似文献   
65.
The catalytic properties of sp3-hybridized ultra-dispersed diamond and sp2-hybridized onion-like carbon in the oxidative dehydrogenation of ethylbenzene to styrene were investigated, highlighting the structure sensitivity of the reaction. The sp3-carbon led initially to C-C cleavage and benzene formation, while a switchover of the main reaction pathway into the styrene formation occurred with time on stream due to the formation of surface sp2 carbon, required for the selective styrene formation. This was confirmed by the behavior and the high stable styrene selectivity shown by onion-like carbons. High temperature oxygen pre-treatment created catalytically active species at the sp2 carbon surface, confirming that a high thermal stability carbon-oxygen complex was the active surface site for forming styrene.  相似文献   
66.
A technological design of reactive distillation processes (catalytic distillation) is discussed that applies liquid-flooded catalytic zones with a cocurrent-cross flow of the liquid, into each of which only a portion of the vapor stream is passed from the zone located below. This allows the cross section of the catalytic zones to be multiply reduced and the local excessive heating in them to be completely eliminated.  相似文献   
67.
A computational algorithm is constructed for solution of the problem of freezing of water-saturated porous media with account for the dependence of the temperature of the phase transition of pore moisture on the pressure and the concentration of a dissolved impurity. The mathematical model of the process considered is based on a generalized formulation of the well-known Stefan problem. Examples convey results of computation.  相似文献   
68.
69.
The effect of disperse graphite on the kinetics and thermodynamics of formation of an ion-exchange matrix was investigated and the basic parameters for production of Polikon K carbon-filled material were selected. The effect of the filler on crosslinking and the yield of finished oligomer was established. Incorporation of colloidal graphite changes the dielectric properties of Polikon K material by increasing its conductivity. __________ Translated from Khimicheskie Volokna, No. 1, pp. 52–54, January–February, 2008.  相似文献   
70.
A concept for building the structure and studying controllable electrotechnical complexes for manufacturing equipment that increase the efficiency of saving energy and resources by optimizing the speed regimes is proposed. Selection of the velocity diagram of transportation, spinning, and winding of synthetic fibres and nonwovens should precede the process study to determine the optimum regime indexes.  相似文献   
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