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31.
This study presents a numerical assessment of the seismic behaviour of an earth embankment founded on liquefiable foundation soils during earthquake loading. Analysis was carried out using an effective stress-based, fully coupled, finite element method. The behaviour of the sandy soil is described by means of a cyclic elastoplastic constitutive model which was developed within the framework of the Armstrong–Frederick type non-linear kinematic hardening concept. The numerical method and the analysis procedure are briefly outlined and as an example, the seismic response of an earth embankment on a saturated sand foundation is assessed. Based on the numerical results, the distinctive patterns of seismic response of the embankment are discussed. Special emphasis is given to the computed results of excess pore water pressures, co-seismic and post-seismic deformations, and accelerations during the seismic excitation. It has been found that the numerical model can capture fundamental liquefaction aspects of the embankment foundation system and produce preliminary results for its seismic assessment.   相似文献   
32.
New-type solar cells, having a structure “transparent conductor/thin Si02 layer with ultrafine metal islands as conductive channels/n-Si” have been prepared by forming a very thin (< 1.0 nm) silicon oxide (Si02) layer as well as platinum (Pt) islands (5–50 nm in size) embedded in it on a single crystal n-type silicon (n-Si) wafer, followed by the deposition of an indium tin oxide (ITO) film (200 nm thick) by the electron-beam evaporation method. The open-circuit photovoltages (Voc) of the solar cells of the above structure were relatively low, 0.25–0.47 V, but they increased very much to 0.50–0.59 V if a thin (3–10 nm) layer of an organic compound such as copper phthalocyanine (CuPc) was pre-deposited on the Pt-island modified n-Si wafer before the ITO deposition. The reason for the beneficial effect of the pre-deposition of the thin CuPc layer was investigated in detail, and it has been found that certain crystal defects are formed in n-Si near the n-Si/Si02 interface during the ITO deposition in the absence of the CuPc layer. The formation of such defects is prevented in the presence of the CuPc layer, which leads to a decrease in surface carrier recombination and hence to the increase in Voc.  相似文献   
33.
We propose a technique, new to our knowledge, for characterizing single-mode operability by monitoring far-field patterns via a variable aperture. We clarify the applicability of our proposed technique to cutoff wavelength measurement, which agrees well with cutoff wavelength obtained by a conventional multimode reference technique. We also show the applicability of our proposed technique to holey fibers including photonic crystal fibers (PCFs) with uniform air-hole structure and effectively W-shaped air-hole structure. We can clearly characterize the single-mode operability of the PCF. The bend dependence of the single-mode bandwidth is also revealed by utilizing our proposed technique.  相似文献   
34.
During the period from May to October 1992, a survey of phlebotomine sandflies was conducted in the Greater Athens region where cases of human and canine leishmaniasis occur. Using castor-oil paper traps, a total of 3015 sandflies were caught. Of the identified specimens, 1002 (34.1%) were Phlebotomus neglectus, 541 (18.4%) were P. papatasi, 182 (6.2%) were P. tobbi, 50 (1.7%) were P. simici, 30 (1.0%) were P. alexandri, 3(0.4%) were P. sergenti and 1122 (38.2%) were Sergentomyia minuta. The seasonal activity of most Phlebotomus species was bimodal, while that of S. minuta was unimodal. The population density of sandflies varied significantly in different localities; it was low in most of the stations and high in some stations in the outskirts. Among the potential vectors of Leishmania spp., P. neglectus and P. Papatasi were the most widespread species. The former species showed high density in 12 of the 70 sampled stations, while the latter in only 4. Hence, the risk of transmission of sandfly-borne diseases is still present in the Greater Athens region.  相似文献   
35.
A new digital control method for a time varying sampled data system called a time varying deadbeat control is proposed for the control of high order nonholonomic chained systems with drift terms. This control law has the potential to avoid excessive overshoot and prevent trajectories from getting close to the singular manifolds of the transformation needed to obtain the chained forms.  相似文献   
36.
We have isolated a beta-tubulin-encoding cDNA clone of Bombyx mori from testes and determined the nucleotide sequence. Northern analyses showed that its expression is testis-specific and most active in the pupal stage.  相似文献   
37.
In recent years, public pressure to reduce the use of synthetic fungicides in agriculture has increased. Concerns have been raised about both the environmental impact and the potential health risk related to the use of these compounds. Therefore, considerable efforts have been made towards the development of alternative crop protectants. The European Commission has been actively encouraging the development and commercial implementation of new compounds known as 'green chemicals'. In this context, an increase in the knowledge of plant defence responses to toxigenic fungi, which is covered in this review, will help to discover new plant products with antifungal activity and to design new strategies to improve plant resistance to these pathogens.  相似文献   
38.
A 66-year-old female presented with anorexia, fatigue, skin pigmentation, weight loss and low grade fever. Imaging studies demonstrated bilateral bulky masses confined to the adrenal glands. Ultrasonography guided needle biopsy of the mass showed findings of diffuse large B-sell lymphoma. Low levels of serum cortisol, urinary 17-OHCS and 17-KS, a high level of ACTH and a non-reactive pattern on the rapid ACTH test led to a diagnosis of Addison's disease. Only a partial regression was achieved by the first chemotherapy. She died due to disease progression, while the next course of chemotherapy had been postponed because of interstitial pneumonitis due to methotrexate.  相似文献   
39.
40.
The minimum primary structure of the IgE-binding epitope in wheat gluten was determined as Gln-Gln-Gln-Pro-Pro. The N-terminal glutamine and the two proline residues were essential for epitopic function. The occurrence of the second glutamine residue and acetylation of the N-terminal amino group were found to exert some auxiliary functions, whereas only a lesser contribution was expected for the third glutamine residue. It has also been confirmed that acetyl-Gln-Gln-Gln-Pro-Pro bound to wheat-specific IgE antibodies in the sera of patients allergic to wheat, although it did not induce histamine release from the basophils of these patients. Taken together, we concluded that the Gln-Gln-Gln-Pro-Pro motif constituted an IgE-binding rather than immunogenic epitope and also that acetyl-Gln-Gln-Gln-Pro-Pro might act as a hapten capable of binding to specific IgE molecules. The possibility exists that this peptide will have practical application to therapy for or prevention of wheat-sensitive allergy.  相似文献   
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