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排序方式: 共有800条查询结果,搜索用时 11 毫秒
81.
A security extension for IEEE Std 1149.1 is proposed. It provides a locking mechanism which prevents unauthorised users to
interfere via test bus with the system normal operation. The security extension requires small hardware overhead and allows
full conformance with IEEE Std 1149.1. 相似文献
82.
Poly{1-[p-(mercaptomethyl)phenyl]ethylene} with a low content of divinylbenzene units as the crosslinking component was prepared from chloromethylated poly(styrene-co-divinylbenzene), and the activity of the thiolate form in the debromination reactions of 1,2-dibromocyclohexane was investigated with respect to the analytical content of the -SH groups. The extent of transformation of the -SH groups into the thiolate form, and the degree of crosslinking of the polymeric carrier were investigated. An almost complete conversion of 1,2-dibromocyclohexane and high yields of cyclohexene were obtained by using polymeric thiols with the initial DVB contents of 1 or 2%; the degree of functionalization of the carrier 100% or 30–60%; and the reaction times of polymeric thiols with sodium methoxide in methanol (1–2h). The debromination reaction required 5h for completion. Under optimum conditions, debromination of 1,2,5,6-tetrabromocyclooctane, α,β-dibromoethylbenzene, α,β,3,4-tetrabromoethylcyclohexane, diethyl2,3-dibromosuccinate and stilbene dibromide gave olefins in yields of 60–100% 相似文献
83.
Lenka Monincová Dr. Milos Buděšínský Sabina Čujová Dr. Václav Čeřovský Dr. Václav Veverka 《Chembiochem : a European journal of chemical biology》2014,15(2):301-308
Lasiocepsin is a unique 27‐residue antimicrobial peptide, isolated from Lasioglossum laticeps (wild bee) venom, with substantial antibacterial and antifungal activity. It adopts a welldefined structure consisting of two α‐helices linked by a structured loop. Its basic residues form two distinct positively charged regions on the surface whereas aliphatic side chains contribute to solvent‐accessible hydrophobic areas, thus emphasising the amphipathic character of the molecule. Lasiocepsin structurally belongs to the ShK family and shows a strong preference for anionic phospholipids; this is further augmented by increasing concentrations of cardiolipin, such as those found at the poles of bacterial cells. The membrane‐permeabilising activity of the peptide is not limited to outer membranes of Gram‐negative bacteria. The peptide interacts with phospholipids initially through its N terminus, and its degree of penetration is strongly dependent on the presence of cardiolipin. 相似文献
84.
Zbyšek Pavlík Lukáš Fiala Miloš Jerman Eva Vejmelková Milena Pavlíková Martin Keppert Robert Černý 《International Journal of Thermophysics》2014,35(9-10):1912-1921
The moisture-dependent thermal conductivity of two types of lightweight ceramic brick body is analyzed using both theoretical and experimental approaches. The basic physical properties are determined at first. Then, an impulse method is applied for the thermal-conductivity measurement. Initially, the material samples are dried, after that, they are exposed to liquid water for specific time intervals, and finally the moisture content is allowed to homogenize within the whole volume. The thermal-conductivity measurement is performed for different moisture contents achieved in this way. In the theoretical part, the homogenization principles are used for the calculation of the moisture-dependent thermal conductivity, utilizing the distribution functions based on the pore-size distribution measurement. Finally, a comparison of the measured and calculated data is done, and the validity of the applied effective media treatment is assessed. 相似文献
85.
86.
The paper presents a two-dimensional simulation study of a polycrystalline Cu(In,Ga)Se2 (CIGS) solar cell with various shapes of grains inside the CIGS absorber layer. The grain boundaries (GBs) with a diverse valence-band offset (VBO) and the density of defect states (NtA) are considered so as to evaluate their effects on the performance of the CIGS cell. The numerical simulations show that a CIGS cell with column-like grains can achieve a high conversion efficiency (η), while the η of a CIGS cell with diamond-like grains is low if the VBO at the GBs exceeds 0.4 eV. The VBO at which the η of the CIGS cell with diamond-like grains peaks is found at 0.20-0.27 eV. A favorable VBO mainly depends on the shape of the grains, but it also depends on the NtA. The simulations of the CIGS cells in the substrate and superstrate configurations showed that their performances change if the VBO is varied. This result also implies that the configuration of the CIGS cell is important and the substrate configuration with larger grains in the space-charge region has a considerable advantage if the VBO ranges from 0 eV to 0.2 eV. 相似文献
87.
Z. F. Tomashik V. G. Ivanits’ka V. N. Tomashik L. P. Shcherbak J. Franc P. Moravec P. Höschl J. Walter 《Inorganic Materials》2010,46(8):812-817
This paper examines the dissolution behavior of the (111)A, (111)B, (110), and (100) surfaces of CdTe single crystals in aqueous H2O2-HI-C6H8O7 (citric acid) solutions. We have determined the dissolution rate of the crystals as a function of temperature and solution
concentration, located the composition regions of polishing and selective etchants, and studied the microstructure and roughness
of surfaces polished with optimized etchants. The etching behavior of CdTe is shown to depend on its crystallographic orientation. 相似文献
88.
The paper presents a new method introducing an anchored discrete convolution for calculating the length of a digital curve. The method is based on discrete convolution by using convolution masks and point anchoring in the pixel. The use of ordinary convolution distorts the curve shape and gives large errors in length calculation. The advantage of anchoring is that it limits the point shifting into the pixel during the calculation of the curve length. The method is applied to an analytical arc and various calculations are performed. In addition different methods from the literature were compared and a real sample was tested. 相似文献
89.
Danijela A. Skobir Franc Vodopivec Ladislav Kosec Monika Jenko Jelena Vojvodi
‐Tuma 《国际钢铁研究》2004,75(3):196-203
The effect of microstructure on creep resistance of the low carbon chromium steel X20CrMoV121 after 100‐hours of static‐load test at a temperature of 580 °C and constant stress of 170 MPa was investigated. The specimens for the experiments were extracted from steam pipes of a steam power plant and heat treated. The effect of isothermal annealing on the microstructure and hardness as well as the kinetics of the precipitation of the carbide particles were determined. 相似文献
90.
R. Grill J. Franc I. Turkevych P. HöSchl E. Belas P. Moravec 《Journal of Electronic Materials》2005,34(6):939-943
The possibility to prepare semi-insulating CdTe with a deep-level doping below the limit 1013 cm−3 demanded in detector industry is studied theoretically within quasi-chemical formalism. We show that proper thermal treatment,
including low temperature (ca 200°C) dwell, allows fulfillment of this demand also in 7N or less purity materials. The procedure
is demonstrated in Te-rich CdTe doped with a shallow donor. Its principle is based on enhanced defect selfcompensation, which
affords at sufficiently low temperature extremely high compensation of shallow defects. New high-temperature transport data
are used to refine on previous native defect properties for the modeling. The analysis of diffusion rates at lowered temperature
approves the model for a real-time experimental verification. 相似文献