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Kojima Masami Tasaki Takafumi Suzuki Yukihisa Kamijo Toshio Hada Aki Kik Alfred Ikehata Masateru Sasaki Hiroshi 《Journal of Infrared, Millimeter and Terahertz Waves》2022,43(3-4):260-271
Journal of Infrared, Millimeter, and Terahertz Waves - Millimeter waves (MMW) absorbed by skin or cornea may induce damage by heat. We have developed a 60 GHz MMW exposure-induced eye... 相似文献
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A novel scheme is presented that can be used to efficiently pump optical waveguide amplifiers. It is based on the coupling between two adjacent waveguides, where pump light is gradually coupled from a nonabsorbing pump waveguide into the amplifier waveguide. The coupling between the waveguides in such a configuration is calculated using an improved coupled mode theory (CMT). The proposed distributed coupling scheme can enhance the optical gain in systems that exhibit a reduced pumping efficiency at high pump power. A numerical example is given for a sensitized neodymium-doped polymer waveguide amplifier, in which the optical gain increases from 0.005 dB to 1.6 dB by changing from conventional butt-coupling to distributed coupling 相似文献
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Larsen EH Lobinski R Burger-Meÿer K Hansen M Ruzik R Mazurowska L Rasmussen PH Sloth JJ Scholten O Kik C 《Analytical and bioanalytical chemistry》2006,385(6):1098-1108
The scope of the work was to investigate the influence of selenate fertilisation and the addition of symbiotic fungi (mycorrhiza)
to soil on selenium and selenium species concentrations in garlic. The selenium species were extracted from garlic cultivated
in experimental plots by proteolytic enzymes, which ensured liberation of selenium species contained in peptides or proteins.
Separate extractions using an aqueous solution of enzyme-deactivating hydroxylamine hydrochloride counteracted the possible
degradation of labile selenium species by enzymes (such as alliinase) that occur naturally in garlic. The selenium content
in garlic, which was analysed by ICP–MS, showed that addition of mycorrhiza to the natural soil increased the selenium uptake
by garlic tenfold to 15 μg g−1 (dry mass). Fertilisation with selenate and addition of mycorrhiza strongly increased the selenium content in garlic to around
one part per thousand. The parallel analysis of the sample extracts by cation exchange and reversed-phase HPLC with ICP–MS
detection showed that γ-glutamyl-Se-methyl-selenocysteine amounted to 2/3, whereas methylselenocysteine, selenomethionine
and selenate each amounted to a few percent of the total chromatographed selenium in all garlic samples. Se-allyl-selenocysteine
and Se-propyl-selenocysteine, which are selenium analogues of biologically active sulfur-containing amino acids known to occur
in garlic, were searched for but not detected in any of the extracts. The amendment of soil by mycorrhiza and/or by selenate
increased the content of selenium but not the distribution of detected selenium species in garlic. Finally, the use of two-dimensional
HPLC (size exclusion followed by reversed-phase) allowed the structural characterisation of γ-glutamyl-Se-methyl-selenocysteine
and γ-glutamyl-Se-methyl-selenomethionine in isolated chromatographic fractions by quadrupole time-of-flight mass spectrometry. 相似文献
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A new concept for an infrared waveguide detector based on silicon is introduced. It is fabricated using silicon-on-insulator material, and consists of an erbium-doped p-n junction located in the core of a silicon ridge waveguide. The detection scheme relies on the optical absorption of 1.5-/spl mu/m light by Er/sup 3+/ ions in the waveguide core, followed by electron-hole pair generation by the excited Er and subsequent carrier separation by the electric field of the p-n junction. By performing optical mode calculations and including realistic doping profiles, we show that an external quantum efficiency of 10/sup -3/ can be achieved in a 4-cm-long waveguide detector fabricated using standard silicon processing. It is found that the quantum efficiency of the detector is mainly limited by free carrier absorption in the waveguide core, and may be further enhanced by optimizing the electrical doping profiles. Preliminary photocurrent measurements on an erbium-doped Si waveguide detector at room temperature show a clear erbium related photocurrent at 1.5 /spl mu/m. 相似文献
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We developed a method to evaluate the mechanical properties of the monolayers in symmetric surfactant bilayers using self-consistent field theory. A specific boundary condition is used to impose the same curvature onto the two opposing monolayers at the surfactant chemical potential equal to that of the corresponding homogeneously curved bilayer. Typically, the spontaneous monolayer curvature not equal 0 and its value depend on the surfactant architecture. This is of importance for the thermodynamics and topology of lamellar surfactant phases. Furthermore, it may be relevant in processes involving biological membranes, for example, the fusion and budding of vesicles and the incorporation of proteins in lipid bilayers. 相似文献
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