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91.
Pyrochlore-structured materials are very important materials due to their structural and conducting properties. These properties
can be further modified by changing processing conditions. In the present study, pyrochlore (Y2Ti2O7) is synthesized using high-energy ball milling. During various stages of ball milling, the ball-milled powder is taken for
investigating the structural and thermal properties. The replacement of Ti2O3 by TiO2 in nominal composition leads to lower ball milling duration to form Y2Ti2O7. Differential thermal analysis showed the single exothermic peak below 800 °C, which indicates formation of disordered pyrochlore
phase. The as prepared powders (40-h ball milled) were compacted and heat treated at 1,450 °C for 12 h. The conductivity of
sintered sample is found to be one order higher than earlier reported pure Y2Ti2O7 pyrochlore. 相似文献
92.
This paper describes the validation of a sensitive, accurate, and reproducible method for the determination of a release profile of glipizide from controlled-release dosage forms. In this method, an in vitro dissolution profile of commercial controlled-release dosage forms is determined using a reversed-phase C(18) column, mobile phase (acetonitrile-buffer, 0.05 M KH(2)PO(4) adjusted to pH 3.5 with orthophosphoric acid), and UV detection at a wavelength of 275 nm. The method is validated for linearity, accuracy, precision, and detection and quantitation limits. The same method can be exploited to determine the plasma concentration of glipizide. The peak area versus plasma concentration is linear over the range of 12.5-1000 ng/mL and the detection limit was 5 ng/mL in plasma. The average accuracy was 99.90% with a relative standard deviation (RSD) of not more than 3%. Repeatability and reproducibility were found to be good with an RSD of less than 3%. 相似文献
93.
H. S. Randhawa R. Sachdeva A. Singla 《Journal of Thermal Analysis and Calorimetry》1986,31(3):675-678
The heats of formation for-
* charge transfer interactions have been computed from the charge transfer spectra of molecular complexes formed between methylbenzene donors and-electron acceptors.Miss Rajni Sachdeva and Anita Singla are grateful to I.C.A.R. (India) and C. S. I. R. (India), respectively, for financial assistance. 相似文献
94.
95.
The metal catalyzed synthesis of heterocycles is becoming an important and highly rewarding protocol in organic synthesis. Traditional approaches require expensive or highly specialized equipment or would be of limited use to the synthetic organic chemist due to their highly inconvenient approaches. Titanium-mediated cyclization reactions have been recognized as some of the simplest and useful tools for regio- as well as stereoselective syntheses of five-membered N-heterocycles. This review summarizes the applications of titanium catalysts with emphasis of their synthetic applications for different heterocylces. This review covered interesting discoveries in the past few years. 相似文献
96.
Meenu Thakur B. R. Behera Ruchi Mahajan N. Saneesh Gurpreet Kaur Priya Sharma R. Dubey Kushal Kapoor A. Yadav Neeraj Kumar S. Kumar Kavita Rani P. Sugathan A. Jhingan A. Chatterjee M. B. Chatterjee S. Mandal A. Saxena Santanu Pal S. Kailas Avazbek Nasirov Bakhodir Kayumov 《The European Physical Journal A - Hadrons and Nuclei》2017,53(6):133
97.
Lycopene is a pigment belonging to the group of carotenoids and it is among the most carefully studied antioxidants found especially in fruit and vegetables. As a carotenoid, lycopene exerts beneficial effects on human health by protecting lipids, proteins, and DNA from damage by oxidation. Lycopene is a powerful oxygen inactivator in the singlet state. This is suggestive of the fact that lycopene harbors comparatively stronger antioxidant properties over other carotenoids normally present in plasma. Lycopene is also reported to hinder cancer cell proliferation. The uncontrolled, rapid division of cells is a characteristic of the metabolism of cancer cells. Evidently, lycopene causes a delay in the progression of the cell cycle, which explains its antitumor activity. Furthermore, lycopene can block cell transformation by reducing the loss of contact inhibition of cancer cells. This paper collects recent studies of scientific evidence that show the multiple beneficial properties of lycopene, which acts with different molecular and cellular mechanisms. 相似文献
98.
A multi-tone radio over fiber (RoF) system design for three RF signals has been investigated for different modulation techniques like direct and external modulation with EDFA and SOA amplification techniques. Frequency response has been studied including the effects of third order intermodulation terms. Frequency separation between the modulating tones has been varied to study its impact on received carrier power. The performance in terms of electrical RF power of three receiving channels at different frequency separations using different amplification techniques have been measured and compared. An improvement in the received RF power and IM suppression has been observed by using an external modulation based system with EDFA amplifier. 相似文献
99.
This paper presents an analytical and numerical investigation of an intense circularly polarized wave propagating along the static magnetic field parallel to oscillating magnetic field in magnetoactive plasma. In the relativistic regime such a magnetic field is created by pulse itself. The authors have studied different regimes of propagation with relativistic electron mass effect for magnetized plasma. An appropriate expression for dielectric tensor in relativistic magnetoactive plasma has been evaluated under paraxial theory. Two modes of propagation as extraordinary and ordinary exist; because of the relativistic effect, ultra-strong magnetic fields are generated which significantly influence the propagation of laser beam in plasma. The nature of propagation is characterized through the critical-divider curves in the normalized beam width with power plane For given values of normalized density (ωp/ω) and magnetic field (ωc/ω) the regions are namely steady divergence (SD), oscillatory divergence (OD) and self-focusing (SF). Numerical computations are performed for typical parameters of relativistic laser-plasma interaction: magnetic field B = 10-100 MG; intensity I = 1016 to 1020 W/cm2; laser frequency ω = 1.1 × 1015 s−1; cyclotron frequency ωc = 1.7 × 1013 s−1; electron density ne = 2.18 × 1020 cm−3. From the calculations, we confirm that a circularly polarized wave can propagate in different regimes for both the modes, and explicitly indicating enhancement in wave propagation, beam focusing/self-guiding and penetration of E-mode in presence of magnetic field. 相似文献
100.