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431.
A. Madhukar Q. Xie P. Chen A. Kalburge T. R. Ramachandran A. Nayfonov A. Konkar 《Journal of Crystal Growth》1995,150(1-4):357-363
We report here the realization of strained InAs three-dimensional islands on GaAs(100) with optical characteristics that reveal lateral quantum confinement (i.e. quantum box behavior). The importance of the cap layer growth conditions and methodology in achieving optically active InAs islands and the existence, range, and impact of island-induced strain fields on the cap layer growth are uncovered via marker layer experiments. Strong optical emission from the InAs islands is observed in correlation with the transmission electron microscope (TEM) observation of uniform coherent islands under optimized growth conditions. Photoluminescence excitation (PLE) spectroscopy reveals the presence of the energy transitions due to the three-dimensional electronic confinement in such InAs islands. The InAs islands buried under the GaAs were found to be quite stable upon annealing to 100°C higher than the growth temperature. 相似文献
432.
Patil Priyanka T. Warekar Poojali P. Patil Kirti T. Undare Santosh S. Jamale D. K. Vibhute S. S. Valekar N. J. Kolekar Govind B. Deshmukh Madhukar B. Anbhule Prashant. V. 《Research on Chemical Intermediates》2018,44(2):1119-1130
Research on Chemical Intermediates - An efficient one-pot synthesis of novel pyrazolo[3,4-b][1,8]naphthyridine and pyrazolo[3,4-d]pyrimido[1,2-a]pyrimidine derivatives has been investigated from... 相似文献
433.
Dillip GR Raghavaiah P Mallikarjuna K Reddy CM Bhagavannarayana G Kumar VR Raju BD 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1123-1127
Single crystals of γ-glycine, an organic nonlinear optical material have been synthesized in the presence of potassium fluoride (KF) by slow evaporation technique at ambient temperature. The size of the grown crystal is up to the dimension of 12 mm×10 mm×8 mm. The γ-phase was confirmed by single crystal X-ray diffraction, powder XRD and the FTIR analysis. Optical absorption spectrum reveals that the grown crystal has good optical transparency in the entire visible region with an energy band gap of 5.09 eV, which is an essential requirement for a nonlinear optical crystal. Thermal stability of the grown γ-glycine crystal was determined using the thermo gravimetric and differential thermal analyses. The NLO activity of γ-glycine was confirmed by the Kurtz powder technique using Nd:YAG laser and the grown crystal exhibits high relative conversion efficiency when compared to potassium dihydrogen phosphate (KDP). 相似文献
434.
Kale VS Sathe BR Kushwaha A Aslam M Shelke MV 《Chemical communications (Cambridge, England)》2011,47(27):7785-7787
A novel, catalyst-free strategy for the direct synthesis of vertically aligned silicon nanowire-carbon nanotube (SiNW-CNT) heterojunction arrays is presented. Such a heterojunction with the junction area in the nanoscale displays enhanced field emission characteristics at low turn-on field, with a nearly three times increase in the field enhancement factor. 相似文献
435.
Raju R. Kale Virendra Prasad Divya Kushwaha Vinod K. Tiwari 《Journal of carbohydrate chemistry》2013,32(2):130-142
A facile, simple, and high-yielding synthetic protocol for novel glycosyl tetrazoles has been devised from different carbohydrate-containing amides using benzotriazole methodology under mild reaction condition. 相似文献
436.
Dipti R. Patil Madhukar B. Deshmukh Sonali M. Salunkhe Prashant V. Anbhule 《Journal of heterocyclic chemistry》2011,48(6):1342-1346
An efficient and simple method has been reported for the synthesis of 2,3,4‐trisubstituted quinolines through zwitterion intermediate under reflux condition in presence of sulfuric acid. The formed dicarboxylate subsequently undergoes transesterification in various alcohols with good yields. Most of the synthesized compounds are newly reported characterized by spectroscopic method. J. Heterocyclic Chem., (2011). 相似文献
437.
Chikhalikar S Bhawe V Ghotekar B Jachak M Ghagare M 《The Journal of organic chemistry》2011,76(10):3829-3836
The nucleophilic vinylic substitution reaction of the aliphatic enaminone 3-dimethylamino-2-formyl acrylonitrile 1 with the nucleophiles malononitrile and ethyl cyanoacetate produced the two unusual reaction adducts 3a and 3b in good to moderate yield under milder reaction conditions. Upon reaction with aromatic amines, these adducts yielded enamines 4 and 5, which eventually cyclized in the presence of base to produce the novel pyridin-2(1H)-one derivatives 8 and 9. 相似文献
438.
Ramhari V. Rote Deepak P. Shelar Sandeep R. Patil Santosh S. Shinde Raghunath B. Toche Madhukar N. Jachak 《Journal of fluorescence》2011,21(1):453-459
Novel pyrazolo-pyrrolo-pyrimidine (PPP) derivatives having remarkable photophysical properties are designed with the help of theoretical semiempirical calculations. These compounds then synthesized successfully and studied effect of substituents on its photophysical properties. Figure
439.
Heterocyclic orthoaminoaldehyde such as 4-amino-3-(4-phenyl)-1-phenyl-1H-Pyrazolo[3,4-b]pyridine-5-carbaldehyde was synthesized by multistep reactions involving reduction of azido derivative 2 with LAH to yield aminoalcohol 3 and oxidation of it with MnO(2) to aminoaldehyde 4.The pyridine ring annulated on to 4 by Friedl?nder condensation using acetophenones in presence of base to obtained pyrazolo[3,4-h][1,6]naphthyridine 5 in excellent yield. Study of photophysical properties of 5 revealed that the absorption and emission of them depends up on the substituents present on benzene ring in newly annulated pyridine ring. 相似文献
440.