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61.
Gnül Yenilmez ifti Mahmut Durmu Elif enkuytu Adem Kl 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(4):881-886
This study dealt with the reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6 (trimer) (1) with phenolphthalein (2) to give the phenolphthalein bridged compounds 3, 4 and 5. The phenolphthalein bridged cyclotriphosphazatriene derivatives are reported for the first time. The new compounds (3–5) are characterized by elemental analysis, mass spectrometry, UV–vis, FT-IR, 1H, 31P NMR and fluorescence spectroscopy. The more bridged phenolphthalein groups show the higher intensity of the absorption bands in the UV–vis spectra. Fluorescence spectrum of compound 3 shows a small band in the lower spectral range, while the spectra of compounds 4 and 5 show more intense and a band in higher spectral range. 相似文献
62.
Brajendra K. Sharma Umer Rashid Farooq Anwar Sevim Z. Erhan 《Journal of Thermal Analysis and Calorimetry》2009,96(3):999-1008
The increasing application of biobased lubricants could significantly reduce environmental pollution and contribute to the
replacement of petroleum base oils. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates
for use as base fluids in formulation of environment friendly lubricants. Although many vegetable oils have excellent lubricity,
they often have poor oxidation and low temperature stability. Here in, we report the lubricant potential of Moringa oil, which
has 74% oleic acid content and thus possess improved oxidation stability over many other natural oils. For comparison, Jatropha
oil, cottonseed oil, canola oil and sunflower oil were also studied. Among these oils, Moringa oil exhibits the highest thermo-oxidative
stability measured using PDSC and TG. Canola oil demonstrated superior low temperature stability as measured using cryogenic
DSC, pour point and cloud point measurements. The friction and wear properties were measured using HFRR. Overall, it was concluded
that Moringa oil has potential in formulation of industrial fluids for high temperature applications.
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard
of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also
be suitable. 相似文献
63.
We approximate the price of the American put for jump diffusions by a sequence of functions, which are computed iteratively.
This sequence converges to the price function uniformly and exponentially fast. Each element of the approximating sequence
solves an optimal stopping problem for geometric Brownian motion, and can be numerically computed using the classical finite
difference methods. We prove the convergence of this numerical scheme and present examples to illustrate its performance. 相似文献
64.
We find the optimal investment strategy to minimize the expected time that an individual’s wealth stays below zero, the so-called
occupation time. The individual consumes at a constant rate and invests in a Black-Scholes financial market consisting of one riskless and
one risky asset, with the risky asset’s price process following a geometric Brownian motion. We also consider an extension
of this problem by penalizing the occupation time for the degree to which wealth is negative. 相似文献
65.
The main object of the present paper is to discuss some extensions of univalence conditions for a family of integral operators. Several other closely-related results are also considered. Many known univalence conditions are shown to follow upon specializing the parameters involved in our main results. 相似文献
66.
With model uncertainty characterized by a convex, possibly non-dominated set of probability measures, the agent minimizes the cost of hedging a path dependent contingent claim with given expected success ratio, in a discrete-time, semi-static market of stocks and options. Based on duality results which link quantile hedging to a randomized composite hypothesis test, an arbitrage-free discretization of the market is proposed as an approximation. The discretized market has a dominating measure, which guarantees the existence of the optimal hedging strategy and helps numerical calculation of the quantile hedging price. As the discretization becomes finer, the approximate quantile hedging price converges and the hedging strategy is asymptotically optimal in the original market. 相似文献
67.
A new amperometric biosensor based on urate oxidase-peroxidase coupled enzyme system for the specific and selective determination of uric acid in urine was developed. Commercially available urate oxidase and peroxidase were immobilized with gelatin by using glutaraldehyde and fixed on a pretreated teflon membrane. The method is based on generation of H2O2 from urine uric acid by urate oxidase and its consuming by peroxidase and then measurement of the decreasing of dissolved oxygen concentration by the biosensor. The biosensor response depends linearly on uric acid concentration between 0.1 and 0.5 μM. In the optimization studies of the biosensor, phosphate buffer (pH 7.5; 50 mM) and 35 °C were obtained as the optimum working conditions. In addition, the most suitable enzyme activities were found as 64.9×10−3 U cm−2 for urate oxidase and 512.7 U cm−2 for peroxidase. And also some characteristic studies of the biosensor such as reproducibility, substrate specificity and storage stability were carried out. 相似文献
68.
In order to study the effect of the presence of phenyl groups in poly (amino-quinone) (PAQ) polymers, several novel poly(amino-2-phenylbenzoquinone) (PhPAQ) polymers have been prepared from 2-phenylbenzoquinone and aliphatic diamines, such as 1,6-diaminohexane, 1,8-diaminooctane, 1,12-diaminodod+++++, and 1,4-diaminocyclohexane. Prior to the polymerization, 2-phenylbenzoquinone was generated in situ from 2-phenylhydroquinone in the presence of calcium hypochlorite as the oxidizing agent in dichloromethane. All of the polymers synthesized have been characterized with respect to their corresponding model compounds. It was also found that unlike their analogous PAQ polymers, PhPAQ polymers were highly soluble in many common organic solvents because of the presence of phenyl groups in their polymer backbone. © 1994 John Wiley & Sons, Inc. 相似文献
69.
W. Lockman T. Meyer J. Rander P. Schlein R. Webb S. Erhan J. Zsembery 《Physics letters. [Part B]》1979,85(4):443-446
A search for the charmed baryon, Λc+, has been carried out in inclusively, measured Λ0π±π+π? and K?π±p final states with longitudinal x > 0.75 in an experiment at the CERN intersecting storage rings. An effect with invariant mass near 2.3 GeV is observed in Λ0π+π+π? with cross section times branching ratio Bσ = (2.8±1.0) μb; similar effect is observed in K?π+p with Bσ = (2.3 ± 0.3) μb. The effect is seen only in the positive charge state, in agreement with an interpretation as Λc+. However, it is pointed out that in the same experiment, the non-charmed hyperon state Σ(1385)+ also has a cross section much larger than its corresponding negative charge state Σ(1385)?. 相似文献
70.