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271.
Isoindolo[2,1-a]quinolines 10 , 11 , 12 were synthesized from hydroxylactams 8 or 9 via an N-acyliminium ion-π-olefin nucleophile cyclization reaction.  相似文献   
272.
The synthesis of isoindolo[2,1-b]pyrrolo[1,2-d][2,4]benzodiazocine 7 and isoindolo[1,2-d]pyrrolo[1,2-a]-[1,5]benzodiazocine 13 are described starting from 2-(2-methoxycarbonyl)benzylphthalimide 1a and ethyl α-bromohomophthalate 9 respectively.  相似文献   
273.
We experimentally designed dispersion-managed repeaterless transmission systems with a pre-compensation and post-compensation technique using multi-channel-chirped fiber Bragg gratings. The repeaterless transmission link supports a single channel(1548.51 nm) with a 10 Gbps repeaterless transmission system over 300 km standard single-mode fiber(SSMF). In the system design, two distributed Raman amplifiers(DRAs) were used to improve the signal level propagated along the 300 km SSMF. The co-propagating DRA provided 15 dB on–off gain and the counter-propagating produced 32 dB on–off gain at the signal wavelength. The experiment results show that the post-compensation configuration achieves an optimal performance with a bit error rate at 1 × 10~(-9).  相似文献   
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Journal of Solid State Electrochemistry - At lower operation temperature of intermediate temperature solid oxide fuel cells (IT-SOFC), polarization resistance was recognized as a limiting step...  相似文献   
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Struvite crystallization is one of the sustainable approaches for recovering ammonium nitrogen (NH4-N) from wastewater in the form of a valuable material, in parallel with improving wastewater treatment efficiency. Focusing on NH4-N recovery, this review discusses the factors influencing struvite crystallization including the effect of foreign elements. It is shown that more than 95% of NH4-N could be recovered in the form of struvite, a magnesium-ammonium phosphate (MAP) salt, from some kinds of wastewater. This review emphasizes the role of utilizing alternative sources of Mg and P in improving the process sustainability. Additionally, it also explains how the MAP precipitation process could result with significant reduction of other pollutants contributing to total organic carbon, of color and turbidity, which support MAP integration with other treatment methods. The main options of lowering MAP recovery cost are presented; it was shown that applying low-cost materials of both Mg and P could save more than 65% of the process’s cost. Finally, the future research directions to improve NH4-N recovery are pointed out.  相似文献   
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Cytogenetic analysis is essential to determine the effect of mutagens and antimutagens on genetic material. This study was done to evaluate the protective effect of root bark extract of Morus alba (M. alba) against cyclophosphamide induced somatic and germinal cell damage in male rats. The ethanolic extract of M. alba (0.25, 0.5 and 1 g/kg, 2 weeks) was evaluated against cyclophosphamide (75 mg/kg, single dose) induced nuclear damage. The sampling was done after 48 h of the clastogen treatment. The somatic and germinal nuclear damage was studied by bone marrow micronucleus and sperm analysis, respectively. Serum superoxide and catalase levels were estimated to determine the antioxidant status in each group. The results were analyzed statistically to find the significant variation. The administration of M. alba for 2 weeks suppressed dose-dependently the changes induced by cyclophosphamide. M. alba (0.5 g/kg) decreased the frequency of micronucleated erythrocyte, sperm shape abnormality and enhanced the sperm count, sperm motility and polychromatic-normochromatic erythrocytes ratio significantly (p < 0.05) in comparison with the cyclophosphamide treated group. The highest tested dose of M. alba (1 g/kg) produced more prominent suppression (p < 0.01) in the cyclophosphamide-induced somatic and germinal cell defects. The results also showed significant (p < 0.05) improvement in the serum antioxidant enzymes levels with M. alba when compared with the challenge group. The lower dose of M. alba extract (0.25 g/kg) prevented the CP-induced changes but was found to be statistically insignificant. Therefore, antimutagenic potential of the high dose of the extract of M. alba is possibly due to its antioxidant nature. The ability of the M. alba extract to prevent the nuclear damage could play an important role in overcoming several mutational defects that are associated with anticancer chemotherapy.  相似文献   
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