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1.
Optimality conditions are derived for a nonliear program in which a support function appears in the objective as well as in each constraint function. Wolfe and Mond-Weir type duals to this program are presented and various dualityresults are established under suitable convexity and generalized convexity assumptions. Special cases that often occur in the literature are those in which a support function is the square root of a positive semidefinite quadratic form or anLp norm. It is pointed out that these special cases can easily be generated from our results. 相似文献
2.
Nitrite is diazotised with p-nitroaniline in hydrochloric acid and coupled with 8-quinolinol in alkaline medium to give a purple azo dye (λmax = 550 nm, ? = 3.88 × 104 l mol-1 cm-1). Extraction of the dye into 3-methyl-1-butanol shifts the absorption maximum to 570 nm and improves the apparent molar absorptivity to 5.852 × 104 l mol-1 cm-1. Beer's law is obeyed for 0.01–0.06 ppm nitrite. The Sandell sensitivity is 0.00078 μg cm-2. The method is applicable to polluted waters. 相似文献
3.
JPC – Journal of Planar Chromatography – Modern TLC - The lipophilic character of phytol derivatives has been studied using reverse-phase planar chromatographic procedures.... 相似文献
4.
We use lookback time versus redshift data from galaxy clusters (Capozziello et al., 2004 [9]) and passively evolving galaxies (Simon et al., 2005 [62]), and apply a Bayesian prior on the total age of the Universe based on WMAP measurements, to constrain dark energy cosmological model parameters. Current lookback time data provide interesting and moderately restrictive constraints on cosmological parameters. When used jointly with current baryon acoustic peak and Type Ia supernovae apparent magnitude versus redshift data, lookback time data tighten the constraints on parameters and favor slightly smaller values of the nonrelativistic matter energy density. 相似文献
5.
The oxidation of phosphinic, phenylphosphinic, and phosphorous acids by N-bromoacetamide (NBA) in acid solution, results in the formation of corresponding higher oxyacids of phosphorus. The reaction is first order with respect to NBA, second order in the oxyacid and inverse first in hydrogen ions. The oxidation of deuteriated phosphorus oxyacids showed the presence of a substantial primary kinetic isotope effect. The reaction failed to induce polymerization of acrylonitrile. Added acetamide has no effect on the reaction rate. It has been shown that the ‘inactive’ tautomer of the phosphorus oxyacids, RHP(O)OH, participates in the oxidation process. A rate-determining step involving transfer of a hydride ion from the P? H bond to the oxidant has been proposed. 相似文献
6.
The B → X (2870–3100 Å) and D → X (2250–2370 Å) band systems of 136Xe35Cl are photographed and vibrationally analyzed. A simultaneous least-squares fit of 41 band-heads in the B-X system and 35 in D-X yields, in part, the following constants (in cm?1): TeB = 32 405.8, TeD = 42 347.9, ωeB = 194.75, ωeD = 204.34, ωeX = 26.22. The ground state dissociation energy (″e) is estimated to be 281 ± 10 cm?1. Potential curves are derived for all three states through Franck-Condon calculations. From these curves the D-state internuclear distance is 0.09 ± .02 Å smaller than the B-state distance. 相似文献
7.
Ghosh K Semwal A Nayak SK Banerjee SB Banerjee M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,66(4-5):1122-1125
[60]- and [70]Fullerenes have been shown to form 1:1 supramolecular complexes with bis[2-(5,11,17,23,29,35-hexa-tert-butyl-37,38,39,40,41-pentahydroxycalix[6]arenyl-oxy ethyl ether) (1) and 5,11,17,23,29,35-hexa-tert-butyl-37,38,40,41-tetra hydroxyl-39,42-(crown-4)calix[6]arene (2) in CHCl3 medium by electronic absorption spectroscopy. Formation constants (K) of the complexes of [60]- and [70]fullerenes with 1 and 2 have been determined at room temperature from which free energy of formation values of the complexes have been estimated. The very high formation constant value of [60]fullerene/1 complex (5900 dm3 mol-1) in indicative of formation of inclusion complex. Moreover, PM3 calculations reveal that intermolecular interaction between [60]fullerene and 1 proceeds through quite deep energy molecular orbital. 相似文献
8.
Cotton fabric was coated with chitosan (CS) and polyethylene glycol (PEG) followed by freeze‐drying. The influence of PEG on the physical characteristics and the surface morphology was investigated. The scanning electron microscopy of the coated fabric revealed a porous structure. The porosity of the material was 54–70% and the pore size was in the range of 75–120µm. The increase in the PEG content in the blend composition led to an enhanced destabilization of pores, leading to an increase in the pore size with elongated morphology. There seems to be phase separation between the two components which is an important factor for the observed behavior of the porous structure. The Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) showed that the CS and PEG have limited interaction. DSC suggested that addition of PEG to CS does not interfere with the crystallization behavior due to limited interaction with CS. The thermogravimetric analysis (TGA) showed that the membranes are thermally stable and PEG enhances the thermal stability of the CS coated membranes. The air and water permeability of the membranes tended to decrease with the increase in the PEG content. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
9.
Aswathy Joseph G.L Praveen K. Abha G.M Lekha Sony George 《Journal of luminescence》2012,132(8):1999-2004
An organic dispersion of 9–15 nm size stable dysprosium oxide incorporated zinc oxide nanocomposites exhibiting luminescence in the visible region has been synthesised by a wet chemical precipitation technique at room temperature. Tetraethoxysilane TEOS [(C2H5O)4Si], (3-aminopropyl) trimethoxysilane (APTS) and a 1:1 mixture of TEOS–APTS have been used as capping agents to control the particle size as well as to achieve uniform dispersion of composite nanoparticles in methanol medium. X-ray diffractometer (XRD) analysis reveals the formation phase of amino-functionalised colloidal dysprosium oxide incorporated ZnO composite nanoparticles to be of zincite structure. The Transmission Electron Microscopy (TEM) images show that the particles are spheroids in shape, having average crystalline sizes ranging from 9 to 15 nm. The photoluminescence (PL) observed in these composites has been attributed to the presence of near band edge excitonic emission and existence of defect centres. The time correlated single photon counting studies of the composite nanoparticles exhibited three decay pathways. The enhanced PL emission intensity of solid state fluorescence spectra of samples is attributed to the absence of vibrational relaxation process. 相似文献
10.
Mishra A 《Applied biochemistry and biotechnology》2006,135(1):33-42
This article reports the production of high levels of l-asparaginase from a new isolate of Aspergillus niger in solid state fermentation (SSF) using agrowastes from three leguminous crops (bran of Cajanus cajan, Phaseolus mungo, and Glycine max). When used as the sole source for growth in SSF, bran of G. max showed maximum enzyme production followed by that of P. mungo and C. cajan. A 96-h fermentation time under aerobic condition with moisture content of 70%, 30 min of cooking time and 1205–1405 μ range
of particle size in SSF appeared optimal for enzyme production. Enzyme yield was maximum (40.9±3.35 U/g of dry substrate)
at pH 6.5 and temperature 30±2°C. The optimum temperature and pH for enzyme activity were 40°C and 6.5, respectively. The
study suggests that choosing an appropriate substrate when coupled with process level optimization improves enzyme production
markedly. Developing an asparaginase production process based on bran of G. max as a substrate in SSF is economically attractive as it is a cheap and readily available raw material in agriculture-based
countries. 相似文献