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排序方式: 共有348条查询结果,搜索用时 15 毫秒
281.
Akanksha Swarnkar Amit Keshav Pankaj Verma A. B. Soni 《Russian Journal of Applied Chemistry》2016,89(2):280-286
Maleic acid, present in the effluent from organic intermediate producing industries, is an industrially important raw material. Its use in manufacture of alkyd and polyester resins, surface coatings, lubricant additives, plasticizers, co-polymers and agricultural chemicals, makes it necessary to explore for best possible techniques to recover it from aqueous solutions. The present work investigates the recovery of maleic acid from aqueous solution at ambient temperature. N–Methyl–n, n–dioctyloctan–1–ammonium chloride, (commercially known as Aliquat 336) is used as an extractant with three different diluents, belonging to different chemical classes: an aromatic hydrocarbon, a ketone, and an acetate. The chemical extraction results are reported in the terms of distribution coefficient, degree of extraction, and loading ratios. The results were modeled by mass action equilibria model as well as differential evolution technique. Differential evolution algorithm has been prepared. The model and experimental observations were compared and fairly good agreement was observed. 相似文献
282.
Ravish Soni Rubej Khan Anand S. Burange Amber J. Sahani Samatha Bavera S.N. Achary Radha V. Jayaram 《印度化学会志》2022,99(10):100680
A framework connected phosphate material K2Ce(PO4)2, explored for the first time for the Knoevenagel condensation of aldehydes with malononitrile in water. The catalyst was prepared by newly developed solid-state method and characterized using XRD, RAMAN, FTIR, BET surface area, TPD, XPS, SEM and HRTEM. The developed protocol showed the substrate compatibility along with the catalyst reusability. Moreover, the catalyst was scaled up to 30 g and also showed reusability. The role of predominant Ce(IV) species was also discussed apart from phosphate basic sites. 相似文献
283.
Garg S Bhaskar T Soni K Muthu Kumaran G Muto A Sakata Y Murali Dhar G 《Chemical communications (Cambridge, England)》2008,(42):5310-5311
FSM-16 (Folded Sheet Silica) supported catalysts could accommodate 12 wt% Mo (18% MoO(3)) as a monolayer with higher dispersion than any other silica support; these catalysts showed outstanding HDS and HYD activities compared to gamma-Al(2)O(3), amorphous silica, and other mesoporous silica supported catalysts. 相似文献
284.
Chandra S Raizada S Rani S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(2):720-724
Palladium(II) and platinum(II) complexes having the general composition [M(L)] X2 (where M=Pd(II) and Pt(II), L=3,4,12,13-tetraphenyl-2,5,11,14,19,20-hexaaza tricyclo [13.3.1.1.(6-10)] cosa-1(19), 2,4,6,8,10,(20),11,13,15,17-decaene (L1); 3,4,13,14-tetraphenyl-2,5,12,15-tetraaza tricyclo [11,0,0,(6-11)] cosa-1(16),2,4,7,9,6(11),12,14,17, 19-decaene (L2); 2,3,8,9-tetraphenyl-1,4,7,10-tetraaza cyclododeca-1,3,7,9-tetraene (L3) and X=Cl(-)) have been synthesized. The ligands were characterized on the basis of elemental analyses, IR, 1H NMR and EI mass spectral studies while that of the complexes were characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, and electronic spectral techniques. All the complexes were found to be diamagnetic. The structures consist of monomeric units in which the Pd(II) and Pt(II) atoms exhibit square planar geometry. 相似文献
285.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Orimoto TJ Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA Del Amo Sanchez P Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG Hearty C Mattison TS 《Physical review letters》2008,100(7):071802
A search for lepton flavor violating decays of a tau to a lighter-mass charged lepton and an omega vector meson is performed using 384.1 fb(-1) of e(+)e(-) annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be B(tau(+/-)-->e;{+/-}omega)<1.1 x10 (-7) and B(tau(+/-)-->micro(+/-)omega)<1.0 x 10(-7) at 90% confidence level. 相似文献
286.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prencipe E Prudent X Tisserand V Tico JG Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lynch G Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG Hearty C Mattison TS McKenna JA Barrett M Khan A Saleem M Teodorescu L 《Physical review letters》2008,101(2):021801
We present measurements of the branching fraction and time-dependent CP asymmetries in B0-->J/psipi0 decays based on 466 x 10(6) Upsilon(4S)-->BB over events collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We measure the CP asymmetry parameters S= -1.23+/-0.21(stat)+/-0.04(syst) and C= -0.20+/-0.19(stat)+/-0.03(syst), where the measured value of (S, C) is 4.0 standard deviations from (0, 0) including systematic uncertainties. The branching fraction is determined to be B(B0-->J/psipi0)=[1.69+/-0.14(stat)+/-0.07(syst)]x10(-5). 相似文献
287.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Tico JG Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lynch G Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG Hearty C Mattison TS McKenna JA Barrett M Khan A Saleem M Teodorescu L 《Physical review letters》2008,101(17):171804
We perform a measurement of the CP asymmetry in b-->sgamma decays using a sample of 383 x 10(6) B[over] B events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X_(s) containing an s quark. We measure the CP asymmetry to be -0.011+/-0.030(stat)+/-0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c(2). 相似文献
288.
The generation, structural elucidation, reactivity, bonding, stability, optimized energy, distortions of optimized topologies of some non-bridged mononuclear and carboxylate bridged binuclear dimethyltin(IV) complexes of N-protected amino acids and 2-aminophenol/2-amino-4-methylphenol were studied experimentally and theoretically with the assistance of density functional theory (DFT). These complexes were synthesized by the reactions of Me2SnCl2 with sodium salts of N-protected amino acids and 2-aminophenol/2-amino-4-methylphenol in 1:1:1 ?molar ratio in refluxing dry THF. These complexes were characterized and their plausible structures were suggested with the assistance of spectroscopic [IR and NMR (1H,13C and 119Sn)] evidences, mass studies and DFT investigation. Mass spectral data indicated the tendency of the complexes to undergo dimerization on aging. The 119Sn NMR data demonstrated the presence of penta-coordinated tin centres in these complexes. DFT (B3LYP) was used to study the molecular orbitals, optimized bond lengths and bond angles, optimized energy, stability, distortions of optimized topologies and energy gap of representative complexes. One representative complex, Me2SnL(2)L’(2) was screened for its possible antimicrobial activities against gram negative bacteria, E. coli and polymorphic fungal pathogen, Candida albicans, respectively. The structure-activity relationship of this complex has also been investigated. 相似文献
289.
Ayushi Sethiya Nusrat Sahiba Jay Soni Shikha Agarwal 《Journal of heterocyclic chemistry》2021,58(3):873-881
A series of substituted 5-chloro-2-arylbenzo[d]thiazoles were synthesized using 4-chloro-2-aminothiophenol and aromatic aldehydes in the presence of urea nitrate as a catalyst using the mechanochemical grindstone technique. This protocol was effectively carried out under metal-free conditions at room temperature, and the desired products were obtained in high to excellent yields in short reaction time (30–60 s). The structure of all the synthesized derivatives was confirmed by spectral characterization. The designed protocol has several benefits like eco-friendly, solvent-free, high yields, easy workup, and recyclability of catalyst. The catalyst was reusable at least four times without significant loss of activity. The good functional group tolerance with a series of derivatives has been demonstrated. 相似文献
290.