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51.
Surface topography of some amorphous films from the T-10 tokamak has been analyzed by using the scanning tunnel microscope. Film surfaces on the scale from ∼10 nm to ∼100 μm have stochastic topography and a hierarchy of granularity. Fractal geometry and statistical physics techniques have been used to study a variety of irregular films within a common framework of the invariance under scaling. Quantitative analysis of a local fracture surface has been made. Experimental probability density functions of surface height increments resemble the Cauchy distribution rather than the Gaussian function. Stochastic topography of the film surface is characterized by the Hurst exponent in the range of 0.68-0.85, indicating non-trivial self-similarity of the structure. A fractality (porosity) of deposited films has to be considered as a critical issue of the tritium inventory in fusion devices. The process of film growth on plasma-facing materials (PFMs) in tokamaks is considered in a frame of the surface growth problem. 相似文献
52.
Berti M De Salvador D Drigo AV Petrovich M Stangl J Schaffler F Zerlauth S Bauer G Armigliato A 《Micron (Oxford, England : 1993)》2000,31(3):285-289
In this work we present some recent results concerning the alpha-particles irradiation of Si1-yCy alloy epitaxially grown on silicon. The study of the damage process is interesting because of the extensive use of backscattering technique as a tool of characterisation of this kind of materials and because of the possibility of adding information about the transformations that this metastable material undergoes. We point out that the irradiation damage process causes a change in the material structure different from that due to the thermal treatments. The irradiation damage occurs at a rate much higher than in Si, however it involves only a silicon atom fraction that appears to be proportional to the substitutional carbon content. 相似文献
53.
Alejandro Petrovich 《Order》1999,16(1):1-17
A modal lattice is a bounded distributive lattice endowed with a unary operator which preserves the join-operation and the smallest element. In this paper we consider the variety CH of modal lattices that is generated by the totally ordered modal lattices and we characterize the lattice of subvarieties of CH. We also give an equational basis for each subvariety of CH. 相似文献
54.
55.
Rohit Malik Ben Mills Jonathan H. V. Price Marco Petrovich Zakaria Moktadir Zhihong Li Harvey N. Rutt 《Applied Physics A: Materials Science & Processing》2013,113(1):127-133
To assess the potential uses of germanium as a nonlinear material in the mid IR we have measured the surface-damage threshold of germanium optical windows using femtosecond pulses at a wavelength of 3.9 μm. By working with a wavelength corresponding to a photon energy of less than half the band-gap energy, free-carrier generation due to one- and two-photon absorption was eliminated. The laser pulses had an energy of 5.5 μJ, a duration of 255 fs, and were focused to a waist size of approximately 100 μm. The multi-shot damage threshold of the germanium windows was estimated to be approximately 94 GW/cm2. The data should be of immediate benefit to industrial laser researchers and applications engineers working in the mid-IR region. 相似文献
56.
RM. Murugappan M. Karthikeyan A. Aravinth MR. Alamelu 《Applied biochemistry and biotechnology》2012,168(8):2170-2183
In the present study, siderophore produced by the marine yeast Aureobasidium pullulans was characterized as hydroxamate by chemical and bioassays. The hydroxamate assignment was supported by the appearance of peaks at 1,647.21?C1,625.99?cm?1 and at 1,435.04?cm?1 in the infrared spectrum. The purified siderophore exhibited specific growth-promoting activity under iron-limited conditions for siderophore auxotrophic probiotic bacteria. Cross-utilization of siderophore indicates a symbiotic relationship between the yeast A. pullulans and the selected probiotic bacterial strains. Statistical optimization of medium components for improved siderophore production in A. pullulans was depicted by response surface methodology. The shift in UV?CVis spectroscopy indicates the photoreactive property and subsequent oxidative cleavage of purified siderophore on exposure to sunlight. 相似文献
57.
K. S. Pramod V. Vijayasundaram N. Krishnakumar PL. RM. Palaniappan 《Journal of Thermal Analysis and Calorimetry》2012,108(1):133-139
This article presents the changes in the thermal properties of the control and titanium dioxide (TiO2), both nano and bulk exposed Zebrafish bones by using thermo analytical techniques. The result shows that the mass loss due
to the thermal decomposition occurs in three distinct steps due to loss of water, organic and inorganic materials. The titanium
dioxide exposed bones present a different thermal behaviour compared to the control bones. The residue masses are found to
be increased due to titanium dioxide exposure. In particular, nano titanium dioxide exposure increases the residue mass level
significantly (three fold) when compared to titanium dioxide bulk exposure. These thermal characteristics can be used as a
qualitative method to check the metal oxide intoxication in biological samples. 相似文献
58.
A. I. Vodchits V. I. Dashkevich N. S. Kazak V. K. Pavlenko V. I. Pokryshkin I. P. Petrovich V. V. Rukhovets A. S. Kraskovskii V. A. Orlovich 《Journal of Applied Spectroscopy》2006,73(2):285-291
We have studied an optical parametric oscillator (OPO) with an unstable telescopic cavity, placed inside the cavity of an
actively Q-switched multimode Nd3+:KGW pump laser. We used a KTP crystal as the nonlinear medium for the OPO. We have compared the emission characteristics
of OPOs with unstable telescopic and planar cavities. We have established that compared with the planar cavity, the unstable
cavity reduces the OPO beam divergence and improves the spatial distribution of the radiation energy in the far wave zone.
Based on our investigations, we have designed a compact eye-safe (λ = 1.578 μm) laser source with natural cooling, emitting
(for electrical pumping energy 7.3 J) pulses with pulse energy 22 mJ and pulse duration 6 nsec. The FWHM beam divergence for
the source is no greater than 3.5 mrad.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 254–259, March–April, 2006. 相似文献
59.
Rubens R Santos Jr Alexandrina Sartori Deison S Lima Patrícia RM Souza Arlete AM Coelho-Castelo Vania LD Bonato Célio L Silva 《Journal of immune based therapies and vaccines》2009,7(1):4-12
Background
Our group previously demonstrated that a DNA plasmid encoding the mycobacterial 65-kDa heat shock protein (DNA-HSP65) displayed prophylactic and therapeutic effect in a mice model for tuberculosis. This protection was attributed to induction of a strong cellular immunity against HSP65. As specific immunity to HSP60 family has been detected in arthritis, multiple sclerosis and diabetes, the vaccination procedure with DNA-HSP65 could induce a cross-reactive immune response that could trigger or worsen these autoimmune diseases. 相似文献60.
A. Andrighetto C. M. Antonucci S. Cevolani C. Petrovich M. Santana Leitner 《The European Physical Journal A - Hadrons and Nuclei》2006,30(3):591-601
The target system is one of the key issues for the facilities aimed at the production of neutron-rich radioactive ion beams.
In the framework of the SPES project (Study for the Production of Exotic Species), the possibility of using a target configuration
with a proton beam (40MeV, 0.2mA) directly impinging on multiple uranium carbide disks is investigated. The 238U fission fragments constitute the source for the exotic beams and for this purpose the disks are placed inside a graphite
box at 2000 °C. The target is split into several thin disks in order to allow the cooling of the system by thermal radiation. In this way
about ∼ 1013 fissions s
-1 are obtained with a relative simple system and with relative low costs. Further steps have been performed compared to previous
publications and now all the main parameters of the system have been analysed by means of calculation codes: the fission rates
and the fission fragment distribution; the power deposition and the thermal analysis; the thermo-mechanical behaviours of
the disks; the effusive and diffusive extraction release properties of the target. 相似文献