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61.
The effect of inhalation of paprine dust on the bronchopulmonary tract and antibody-forming function of the spleen was studied experimentally on two lines of mice: CBA and CC57W, differing from each other by haplotype H-2 and antioxidant status of the organisms under study. During comparative histomorphological examination of lungs and bronchi of the experimental animals a more intensive reaction was found in mice of the CBA line, whereas in mice of the CC57W line vascular changes prevailed without any reactions in the bronchioles. Reactions of the spleen to paprine dust in animals of different lines were also different: the quality of antibody-forming cells in the spleen of CBA line mice with comparatively higher antioxidant status increased under experimental conditions, while it decreased in those of the CC57W line. The data obtained showed dependance of the sensitivity of the organism to action of operational dust on individual genetic properties, demonstrating thus the necessity of applying principles of medical genetics in order to prevent effectively the development of occupational diseases in exposed teams of workers. 相似文献
62.
Elastic modulus degradation, strength reduction, and energy dissipation have traditionally been the properties of choice to monitor the damage process in cortical bone. However, these properties only provide limited insight into the damage process given the complex mechanical nature of bone. In the current study, alternative measures of the damage process were investigated for machined human cortical bone specimens loaded under torsion. Seventy-two bone specimens from 6 human femurs were subjected to a series of torsional relaxation cycles in which damage was induced during a single relaxation cycle and the effects of damage on the elastic, yield, viscous, and failure properties were determined from pre- and post-damage relaxation cycles. The results revealed that degradation of all torsion properties exhibited a significant twist magnitude effect. However, the yield stress and strain, the relaxation rate, and the total relaxation exhibited 5-10 fold greater degradation than both strength and modulus, when residual strength tests were conducted at high shear strain rates. For the loading conditions examined in this study, the results indicated that the relaxation and yield properties of cortical bone are more sensitive to shear damage accumulation and better measures of the damage process than either strength or modulus. Further, the results reveal an important interaction between damage and the viscous behavior of bone which provides new insight into the effects of damage on bone mechanical properties. 相似文献
63.
The purpose of this paper is to inform commercial building designers about an energy analysis tool which can aid them in making appropriate decisions about daylighting. The energy nomographs are an energy design tool which calculate the annual energy consumption of commercial buildings, including lighting, heating, cooling, domestic hot water, fans, pumps, and miscellaneous items. This paper specifically discusses the daylighting aspects of the tool. The calculation procedure is presented with an example to explain how this design tool can be used to make good energy decision eearly in the design process. 相似文献
64.
Potin D. Vanheeghe P. Duflos E. Davy M. 《Geoscience and Remote Sensing, IEEE Transactions on》2006,44(2):260-272
Ground-penetrating radars (GPRs) are very promising sensors for landmine detection as they are capable of detecting landmines with low metal contents. GPRs deliver so-called Bscan data which are, roughly, vertical slice images of the ground. However, due to the high dielectric permittivity contrast at the air-ground interface, a strong response is recorded at early time by GPRs. This response is the main component of the so-called clutter noise and it blurs the responses of landmines buried at shallow depths. The landmine detection task is therefore quite difficult. This paper proposes a new method for automated detection and localization of buried objects from Bscan records. A support vector machine algorithm for online abrupt change detection is implemented and proves to be efficient in detecting buried landmines from Bscan data. The proposed procedure performance is evaluated using simulated and real data. 相似文献
65.
66.
Ramli M Fukumoto K Niki H Abdulmadjid SN Idris N Maruyama T Kagawa K Tjia MO Pardede M Kurniawan KH Hedwig R Lie ZS Lie TJ Kurniawan DP 《Applied optics》2007,46(34):8298-8304
This experiment was carried out to address the need for overcoming the difficulties encountered in hydrogen analysis by means of plasma emission spectroscopy in atmospheric ambient gas. The result of this study on zircaloy-4 samples from a nuclear power plant demonstrates the possibility of attaining a very sharp emission line from impure hydrogen with a very low background and practical elimination of spectral contamination of hydrogen emission arising from surface water and water vapor in atmospheric ambient gas. This was achieved by employing ultrapure ambient helium gas as well as the proper defocusing of the laser irradiation and a large number of repeated precleaning laser shots at the same spot of the sample surface. Further adjustment of the gating time has led to significant reduction of spectral width and improvement of detection sensitivity to ~50 ppm. Finally, a linear calibration curve was also obtained for the zircaloy-4 samples with zero intercept. These results demonstrate the feasibility of this technique for practical in situ and quantitative analysis of hydrogen impurity in zircaloy-4 tubes used in a light water nuclear power plant. 相似文献
67.
Ke Yan Zang Davy W. C. Cheong Hong Fei Liu Hong Liu Jing Hua Teng Soo Jin Chua 《Nanoscale research letters》2010,5(6):1051-1056
The release and transfer of GaN epilayers to other substrates is of interest for a variety of applications, including heterogeneous
integration of silicon logic devices, III–V power devices and optical devices. We have developed a simple wet chemical etching
method to release high-quality epitaxial III-nitride films from their substrates. This method builds on a nanoepitaxial lateral
overgrowth (NELO) process that provides III-Nitride films with low dislocation densities. NELO is accomplished using a nanoporous
mask layer patterned on GaN substrates. Chemical removal of the SiO2 layer after growth of III-Nitride overlayers causes fracture at the interface between the GaN film and the original GaN substrate,
resulting in free-standing GaN films with nanostructured surfaces on one side. These layers can be transferred to other substrates,
and the nano-structured surface can be used in photonic devices, or planarized for power devices. 相似文献
68.
69.
Olivier Kim-Hak Gabriel Ferro Jean Lorenzzi Davy Carole Jacques Dazord Patrick Chaudouët Philippe Miele 《Thin solid films》2010,518(15):4234-3145
The contact between α-SiC crystals and Si-Ge based melts provokes the nucleation of 3C-SiC islands on the crystal surface. Evolution of these islands as a function of various parameters was studied. On both 4H and 6H substrates, it was found that, after nucleation, 3C-SiC islands first enlarge and may form a complete 3C layer under certain conditions. The 3C deposit can then be dissolved by the liquid phase at high temperature or for prolonged contact at relatively moderate temperature. The graphite crucible is proposed to play a central role in these enlargement and dissolution mechanisms by providing extra carbon atoms on the seed surface (enlargement) or provoking thermal induced carbon transport toward the sidewall (dissolution). Several differences between the use of 4H and 6H substrates were also observed. 相似文献
70.
Five studies show that mood affects context-dependence, such that negative mood promotes attention to a salient target, whereas positive mood enhances attention to both target and context. Judgments of temperature (Study 1), weight (Study 2), and size (Studies 3 and 4) were more strongly affected by the context in a positive than in a negative mood. Moreover, these effects extend to the social domain: When perceiving a target person's emotions, happy people were more influenced by the context than were sad people (Study 5). Thus, positive mood enhanced, and negative mood reduced, the magnitude of perceptual context effects. The results suggest that this pattern is not easily explained in terms of effort or depth of processing differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献