排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
Bishnu P. Biswal Sreeramulu Valligatla Mingchao Wang Tanmay Banerjee Nabil A. Saad Bala Murali Krishna Mariserla Naisa Chandrasekhar Daniel Becker Matthew Addicoat Irena Senkovska Reinhard Berger D. Narayana Rao Stefan Kaskel Xinliang Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):6970-6974
Covalent organic frameworks (COFs) have garnered immense scientific interest among porous materials because of their structural tunability and diverse properties. However, the response of such materials toward laser‐induced nonlinear optical (NLO) applications is hardly understood and demands prompt attention. Three novel regioregular porphyrin (Por)‐based porous COFs—Por‐COF‐HH and its dual metalated congeners Por‐COF‐ZnCu and Por‐COF‐ZnNi—have been prepared and present excellent NLO properties. Notably, intensity‐dependent NLO switching behavior was observed for these Por‐COFs, which is highly desirable for optical switching and optical limiting devices. Moreover, the efficient π‐conjugation and charge‐transfer transition in ZnCu‐Por‐COF enabled a high nonlinear absorption coefficient (β=4470 cm/GW) and figure of merit (FOM=σ1/σo, 3565) value compared to other state‐of‐the‐art materials, including molecular porphyrins (β≈100–400 cm/GW), metal–organic frameworks (MOFs; β≈0.3–0.5 cm/GW), and graphene (β=900 cm/GW). 相似文献
2.
3.
4.
B. Venkateswara Reddy K. V. N. Suresh Reddy J. Sreeramulu G. V. Kanumula 《Chromatographia》2007,66(1-2):111-114
A rapid, specific reversed phase HPLC method has been developed for simultaneous determination of olanzapine and fluoxetine
in their formulations. Chromatographic separation of these two pharmaceuticals was carried out on an Inertsil C18 reversed phase column (150 mm × 4.6 mm, 5 μm) with a 40:30:30 (v/v/v) mixture of 9.5 mM sodium dihydrogen phosphate (pH adjusted to 6.8 ± 0.1 with triethylamine), acetonitrile and methanol as
mobile phase. The flow rate 1.2 mL min−1 and the analytes are monitored at 225 nm. Paroxetine was used as internal standard. The assay results were linear from 25
to 75 μg mL−1 for olanzapine (r
2 ≥ 0.995) and 100–300 μg mL−1 for fluoxetine (r
2 ≥ 0.995), showed intra- and inter-day precision less than 1.0%, and accuracy of 97.7–99.1% and 97.9–99.0%. LOQ was 0.005
and 0.001 μg mL−1 for olanzapine and fluoxetine, respectively. Separation was complete in less than 10 min. Validation of the method showed
it to be robust, precise, accurate and linear over the range of analysis. 相似文献
5.
6.
JPC – Journal of Planar Chromatography – Modern TLC - Recently, considerable numbers of poisoning cases have been reported owing to the ingestion of three structurally related... 相似文献
7.
8.
S. Vijayalaxmi P. Prakash S. K. Jayalakshmi V. H. Mulimani K. Sreeramulu 《Applied biochemistry and biotechnology》2013,171(2):382-395
The alkaliphilic Bacillus halodurans strain PPKS-2 was shown to produce extracellular extreme alkaliphilic, halotolerent, detergent, and thermostable mannanase activity. The cultural conditions for the maximum enzyme production were optimized with respect to pH, temperature, NaCl, and inexpensive agro wastes as substrates. Mannanase production was enhanced more than 4-fold in the presence of 1 % defatted copra meal and 0.5 % peptone or feather hydrolysate at pH 11 and 40 °C. Mannanase was purified to 10.3-fold with 34.6 % yield by ion exchange and gel filtration chromatography methods. Its molecular mass was estimated to be 22 kDa by SDS-PAGE. The mannanase had maximal activity at pH 11 and 70 °C. This enzyme was active over a broad range of NaCl (0–16 %) and thermostable retaining 100 % of the original activity at 70 °C for 3 h. Immobilization of whole cells proved to be effective for continuous production of mannanase. Since the strain PPKS-2 grows on cheaper agro wastes such as defatted copra meal, corn husk, jowar bagasse, and wheat bran, these can be exploited for mannanase production on an industrial scale. 相似文献
9.
Pathange Prakash Senigala K. Jayalakshmi Kuruba Sreeramulu 《Applied biochemistry and biotechnology》2010,160(7):1909-1920
An extremely alkaliphilic bacterial strain, Bacillus sp. PPKS-2, was isolated from rice mill effluents and screened for the production of extracellular keratinase. The maximum
production of keratinase occurred after 48 h in shaking culture at pH 11.0 and 37 °C in a medium containing 0.5% soybean flour.
The strain grew and produced alkaline keratinase using chicken feather and horn meal as the sole source of carbon and nitrogen.
An addition of 0.1% soybean flour or feather hydrolysate and sodium sulfite to feather medium increased the production and
complete solubilization of feather took place within 5 days under solid-state fermentation conditions. The partially purified
enzyme displayed maximum activity at pH 11.0 and 60 °C in a broad range of NaCl, 0–16%, and was not inhibited by sodium dodecyl
sulfate (10%), ethylenediaminetetraacetic acid (10 mM), H2O2 (15%), and other commercial detergents. Immobilization of the whole cells proved to be useful for continuous production of
keratinase and feather degradation. The enzyme was effectively used to remove hair from goat hide. The strain PPKS-2 can be
effectively used for solid waste management of poultry feather in submerged as well as solid-state fermentation. 相似文献
10.
Sreeramulu Nagubandi 《Journal of mass spectrometry : JMS》1980,15(10):535-538
Fragmentations of various 2-phenethylamides, trifluoroacylimidates and imidoyl trifluoromethyl sulfonates have been studied and a pathway for the formation of retro-Ritter reaction products is proposed. 相似文献