We proposed a structure of a 1.55 μm InGaAsP/InP superluminescent diode (SLD) to suppress the lasing action and fabricated laterally tilted multi-quantum well planar buried heterostructure separate confinement heterostructure SLD by using MOCVD and LPE equipments. The fabricated SLD is laterally tilted by 15°. The output power of SLD was 11 mW for 200 mA under pulse driving. The full-width at half-maximum was 42 nm at 200 mA. 相似文献
We define an ultra LI-ideal of a lattice implication algebra and give equivalent conditions for an LI-ideal to be ultra. We show that every subset of a lattice implication algebra which has the finite additive property can be extended to an ultra LI-ideal. 相似文献
The interaction between dislocations and nitride precipitates during high-temperature creep deformation of high manganese austenitic steels has been investigated by transmission electron microscopy. Most of the dislocations activated by applied stress were dissociated into Shockley partials. The fine TiN precipitates are pinning and/or incorporating the bow-type moving dislocations and they turned out to be more effective than the coarser TaN in disturbing the dislocation movement. 相似文献
In this paper, we evaluated the behavior of fibrous cerium (IV) acid phosphate (CeP) in insertion procedures involving a strong Lewis base (ethylamine) and a weak one (ɛ-caprolactam). In the former case, the procedure was performed by exposing a sample of CeP to a saturated amine atmosphere. Insertion was shown to be independent of the crystallinity of CeP, and the products showed strong host–guest interactions of the Coulombic type. Conversely, ɛ-caprolactam insertion was achieved by immersing CeP samples into its fused form. This process was dependent on the crystallinity of the inorganic solid, and host–guest interactions were characterized as involving hydrogen bonds. 相似文献
One or few observations can be highly influential on the Kaplan-Meier estimator, and consequently on the log-rank test statistic
in comparing two survival functions. In this paper we derive case influence diagnostics for the Kaplan-Meier estimator and
the log-rank test. We note that diagnostics in this context is quite different from the regression context where observations
are usually assumed to be independent. Simulation studies are done to present some guidelines to determine influential observations
deserving special attention. Illustrative examples are also given. 相似文献
Methods of increasing the enzymatic digestibility of waste newspaper by adding Tween (TW)-20 and 80 surfactants were investigated.
Tween-series surfactants were selected because these surfactants increase cellulase activity during enzymatic hydrolysis and
do not inhibit cell growth in downstream fermentation processes. When surfactant was used in a pretreatment, a benefic effect
was expected in the enzymatic hydrolysis stage owing to surfactant carry-over from the pretreatment stage immediately upstream
of the hydrolysis. However, because it was necessary to wash the pretreated substrate with water to remove inhibitors produced
during pretreatment, no added benefit was obtained. When surfactant was used in the pretreatment only, it was found that it
had a marked effect on digestibility and that this effect was higher at lower enzyme loadings. Also, TW-80 was found to be
more effective than TW-20, and the addition of enzyme and TW-80 to substrate at the beginning of enzyme reaction was found
to most effectively increase digestibility. When TW-80 was added into either the pretreatment stage or the hydrolysis stage
the digestibilities of untreated sample increased by approx 40%, whereas an increase of only 45% was observed when TW-80 was
added to both stages. These results show that the addition of surfactant to either the pretreatment or the enzymatic hydrolysis
stage is sufficient to increase digestibility. 相似文献
Mononuclear nonheme high‐spin (S=2) iron(IV)–oxo species have been identified as the key intermediates responsible for the C?H bond activation of organic substrates in nonheme iron enzymatic reactions. Herein we report that the C?H bond activation of hydrocarbons by a synthetic mononuclear nonheme high‐spin (S=2) iron(IV)–oxo complex occurs through an oxygen non‐rebound mechanism, as previously demonstrated in the C?H bond activation by nonheme intermediate (S=1) iron(IV)–oxo complexes. We also report that C?H bond activation is preferred over C=C epoxidation in the oxidation of cyclohexene by the nonheme high‐spin (HS) and intermediate‐spin (IS) iron(IV)–oxo complexes, whereas the C=C double bond epoxidation becomes a preferred pathway in the oxidation of deuterated cyclohexene by the nonheme HS and IS iron(IV)–oxo complexes. In the epoxidation of styrene derivatives, the HS and IS iron(IV) oxo complexes are found to have similar electrophilic characters. 相似文献
Lyoluminescence (LL) is a good technique for radiation dosimetry of high-energy radiations. Dosimetry of γ rays from 60Co radioactive source has been done using MgB4O7:Mn2+ phosphor material. It was synthesized by simple solid state diffusion method. The material shows good linear LL response with the γ rays for the dose rage of 10 Gy–10 kGy. The studies have also been done for different particle sizes (250–45 µm) and particles having average size ~85 µm were found to be the most suitable for this dosimetry. Effect of solvent pH on LL and fading on storage has also been studied. 相似文献
Horseradish peroxidase (HRP) and hydrogen peroxide (H2O2)‐mediated crosslinking reaction has become an attractive method to create in situ forming hydrogels. While the crosslinking system has been widely utilized, there are certain issues require improvement to extend their biomedical applications, including creation of stiff hydrogels without compromising cytocompatibility due to initially high concentrations of H2O2. A gelatin‐based hydrogels formed through a dual enzyme‐mediated crosslinking reaction using HRP and glucose oxidase (GOx) as an H2O2‐generating enzyme to gradually supply a radical source in HRP‐mediated crosslinking reaction is reported. The physicochemical properties can be controlled by varying enzyme concentrations. Furthermore the hydrogel matrices provide 3D microenvironments for supporting the growth and spreading of human dermal fibroblasts with minimized cytotoxicity, despite the cells being encapsulated within stiff hydrogels. These hydrogels formed with HRP/GOx have great potential as artificial microenvironments for a wide range of biomedical applications.