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961.
Harsh Kumar Mandeep Kaur Rekha Gaba Kirtanjot Kaur 《Journal of Thermal Analysis and Calorimetry》2011,105(3):1071-1080
Densities and speeds of sound of the cyclopentane with 2-propanol, 1-butanol and 2-butanol are measured over the whole composition
range at different temperatures in the range 288.15–308.15 K and atmospheric pressure using Anton Paar DSA 5000 densimeter.
The experimental densities and speeds of sound have been used to calculate excess molar volumes, excess molar isentropic compressibilities
and excess intermolecular free length. The partial molar volumes and apparent molar volumes at infinite dilution have also
been calculated. The mixing quantities like (∂V
mE/∂T)P and (∂H
mE/∂P)T have been calculated at T = 298.15 K and these values are compared with the values calculated from Flory’s theory at equimolar composition. 相似文献
962.
Lotfi et al. [Solving a full fuzzy linear programming using lexicography method and fuzzy approximate solution, Appl. Math. Modell. 33 (2009) 3151–3156] pointed out that there is no method in literature for finding the fuzzy optimal solution of fully fuzzy linear programming (FFLP) problems and proposed a new method to find the fuzzy optimal solution of FFLP problems with equality constraints. In this paper, a new method is proposed to find the fuzzy optimal solution of same type of fuzzy linear programming problems. It is easy to apply the proposed method compare to the existing method for solving the FFLP problems with equality constraints occurring in real life situations. To illustrate the proposed method numerical examples are solved and the obtained results are discussed. 相似文献
963.
A convenient method for in situ synthesis of silver nanoparticles was developed to realize the multifunction of cotton. The silver nanoparticles were obtained through reduction of silver ions by cotton under basic condition at room temperature. The as-synthesized silver nanoparticles achieved the coloration of cotton fibers. Heating increased the color strength of cotton fibers with silver nanoparticles. Mercerization treatment as a common finishing process enhanced the properties of cotton fibers modified by silver nanoparticles. The mercerized cotton exhibited brighter color and had very good colorfastness to washing. The cotton fibers treated with in situ synthesized silver nanoparticles possess strong antibacterial activity with excellent washing durability. 相似文献
964.
Summary The reaction of 3,4-methylenedioxycinnamic acid (1) with thionyl chloride resulted in the formation of 7-chlorothieno[2,3-f]-1,3-benzodioxole-6-carbonyl chloride (2) and cinnamoyl chloride (3). Subsequent reaction of the former withp-substituted anilines led to the formation of 7-chloro-N-(p-substituted phenyl)-thieno[2,3-f]-1,3-benzodioxole-6-carboxamides (4a–c) which on photocyclization afforded 2-substituted [1,3]dioxolo[5,6][1]benzothieno[2,3-c]quinolin-6(5H)-ones (5a–c) in fairly good yields and high purity. The structures have been confirmed by IR,1H NMR, and analytical methods.Accepted for presentation at the Hong Kong International Symposium on Heterocyclic Chemistry (August 13–16, 1995) 相似文献
965.
A. S. Brar Sukhdeep Kaur 《Journal of polymer science. Part A, Polymer chemistry》2005,43(5):1100-1118
Copolymers of methyl methacrylate (MMA) and n‐butyl acrylate (n‐BA) were synthesized under atom transfer radical polymerization (ATRP) conditions. The molar infeed ratio was varied to obtain copolymers with different compositions. Methyl 2‐bromo propionate was used as the initiator with CuBr/Cu(0)/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalyst at 60 °C. Molecular weight distribution was determined by gel permeation chromatography (GPC). Copolymer compositions (FM) were calculated from 1H NMR spectra. Reactivity ratios calculated with the Mao–Huglin terminal model at a high conversion were found to be rM = 2.17 and rB = 0.47. The polymerization mechanism was studied with the α‐methyl region of MMA. The backbone methylene and carbonyl carbons of both MMA and n‐BA units were found to be compositionally as well as configurationally sensitive. Complete spectral assignments were performed with the help of heteronuclear single quantum coherence (HSQC) spectroscopy along with total correlated spectroscopy (TOCSY). Further, the assignments of the carbonyl region were made with the help of heteronuclear multiple quantum coherence (HMBC) spectroscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1100–1118, 2005 相似文献
966.
Tarlok S Lobana Amarjeet Singh Mandeep Kaur Alfonso Castineiras 《Journal of Chemical Sciences》2001,113(2):89-94
Reaction of mercury(II) diiodide with triphenyl selenophosphorane-Se (1:1 mole ratio) in acetone followed by recrystallisation
of the product from chloroform formed crystals of stoichiometry HgI2(Ph3PSe)(1). Compound1 exists as a centrosymmetric homobimetallic dimer, Hg(Μ-I)I(Ph3PSe)2, as monoclinic crystals of space group P21/n. The dimer comprises two Μ2-iodo atoms that form unequal Hg-I bonds 2.8230(10), 3.1135(9) ? and two equal terminal Hg-I bonds 2.6524(10) ?. The Se atom
of Ph3PSe forms terminal Hg-Se bond 2.5914(11)? and thus the geometry about each Hg centre is distorted tetrahedral and the range
of tetrahedral bond angles is 92.97(2) to 130.85(3)‡, the largest being that of Se(1)-Hg(1)-I(1) and the shortest, I(2)-Hg(1)-I(2)‡.
Hg-Hg and I-I separations of 4.0930(11)? and 4.3097(15)? are more than the sums of their respective van der Waal radii 3.00
? and 4.24 ?. 相似文献
967.
Kiran Singh Rajneesh Mohan Nupinder Kaur N.K. Gaur Manglesh Dixit Vilas Shelke R.K. Singh 《Physica C: Superconductivity and its Applications》2006,450(1-2):124-128
The effects of Cu doping in MgB2 superconductor has been studied at different processing temperatures. The polycrystalline samples of Mg1−xCuxB2 with x = 0.05 were synthesized through the in-situ solid sate reaction method in argon atmosphere at different temperature range between 800–900 °C. The samples were characterized through X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and low temperature R–T measurement techniques for the phase verification, microstructure and superconducting transition temperature, respectively. The XRD patterns of Mg1−xCuxB2 (x = 0.05) do not exhibit any impurity traces of MgB4 or MgB6 and they show the sharp transition in the samples prepared at 850 °C. The onset transition temperature of the prepared samples is around 39 K, which is almost the same as that for the pure MgB2. This indicates that Cu doping in MgB2 does not affect the transition temperature. The SEM micrograph of Mg0.95Cu0.05B2 has shown that the sample is dense with grain size smaller than 1 μm. 相似文献
968.
Rakesh Kumar Mahajan Ravneet Kaur Inderpreet Kaur Vandana Sharma Manoj Kumar 《Analytical sciences》2004,20(5):811-814
A PVC membrane incorporating p-tert-butyl calix[4]crown with imine units as an ionophore was prepared and used in an ion-selective electrode for the determination of mercury(II) ions. An electrode based on this ionophore showed a good potentiometric response for mercury(II) ions over a wide concentration range of 5.0 x 10(-5) - 1.0 x 10(-1) M with a near-Nernstian slope of 27.3 mV per decade. The detection limit of the electrode was 2.24 x 10(-5) M and the electrode worked well in the pH range of 1.3 - 4.0. The electrode showed a short response time of less than 20 s. The electrode also showed better selectivity for mercury(II) ions over many of the alkali (Na+, -1.69; K+, -1.54), alkaline-earth (Ca2+, -3.30; Ba2+, -3.32), and heavy metal ions (Co2+, -3.67; Ni2+, -3.43; Pb2+, -3.31; Fe3+, -1.82). Ag+ ion was found to be the strongest interfering ion. Also, sharp end points were obtained when the sensor was used as an indicator electrode for the potentiometric titration of mercury(II) ions with iodide and dichromate ions. 相似文献
969.
A. S. Brar Sukhdeep Kaur 《Journal of polymer science. Part A, Polymer chemistry》2006,44(5):1745-1757
The homopolymerization of N‐vinylcarbazole was performed with atom transfer radical polymerization (ATRP) with Cu(I)/Cu(II)/2,2′‐bipyridine (bpy) as the catalyst system at 90 °C in toluene. N‐2‐Bromoethyl carbazole was used as the initiator, and the optimized ratio of Cu(I) to Cu(II) was found to be 1/0.3. The resulting homopolymer, poly(N‐vinylcarbazole) (PVK), was formed after a monomer conversion of 76% in 20 h. The molecular weight as well as the polydispersity index (PDI) showed a linear relation with the conversion, which showed control over the polymerization. A semilogarithmic plot of the monomer conversion with time was linear, indicating the presence of constant active species throughout the polymerization. The initiator efficiency and the effect of the variation of the initiator concentration on the polymerization were studied. The effects of the addition of CuBr2, the variation of the catalyst concentration with respect to the initiator, and CuX (X = Br or Cl) on the kinetics of homopolymerization were determined. With Cu(0)/CuBr2/bpy as the catalyst, faster polymerization was observed. For a chain‐extension experiments, PVK (number‐average molecular weight = 1900; PDI = 1.24) was used as a macroinitiator for the ATRP of methyl methacrylate, and this resulted in the formation of a block copolymer that gave a monomodal curve in gel permeation chromatography. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1745–1757, 2006 相似文献
970.
Using modified Baker-Venkataraman reaction a novel class of 3-acyl flavones and chromones have been synthesised. Reaction mechanism for their formation have been elucidated. The properties of 3-acyl flavonoids indicate them to be precursors for the synthesis of flavones. 相似文献