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排序方式: 共有116条查询结果,搜索用时 15 毫秒
71.
72.
Sanjay Kapoor Renu Sachar Kuldeep Singh Vivek K. Gupta Rajnikant 《Journal of chemical crystallography》2012,42(5):458-463
Abstract
The [Ni(S2COCH2CH2CH3)2(C6H4N2)2] adduct of 4-cyanopyridine with [Ni(S2COCH2CH2CH3)2] was synthesized and characterized by elemental analysis, magnetic susceptibility measurement, IR, electronic spectral data, Thermogravimetric analysis/DTA techniques and X-ray diffraction analysis. The Ni atom in the title complex is octahedrally coordinated within a trans-N2S4 donor set, with the Ni atom located on a centre of inversion. The title complex crystallizes in the monoclinic space group P2 1 /c with unit cell parameters a = 11.75(4), b = 11.62(3), c = 9.20(2) ?, β = 104.99(3)°. Crystal structure was solved by direct methods and refined by full matrix least squares procedures to a final R-value of 0.0294 for 1895 observed reflections. The packing of layers of molecules is stabilized by weak C–H···N and C–H···π interactions. 相似文献73.
A simple, rapid and sensitive constant wavelength synchronous fluorescence method is developed for the determination of danofloxacin (DAN) in pharmaceutical formulations and its residue in milk based on Al(III) enhanced fluorescence. The synchronous fluorescence intensity of the system is measured at 435?nm using ? λ?=?80?nm and an excitation wavelength of 280?nm. A good linear relationship between enhanced fluorescence intensity and DAN concentration is obtained in the range of 3-100?ng?mL(-1)(r (2)?=?0.9991). The limit of detection (LOD, S/N?=?3) of the present method is 0.9?ng?mL(-1). The proposed method can be successfully applied to the determination of DAN in pharmaceutical formulations and in milk without serious interferences from common excipients, metal ions and other co-existing substances. The method can be used as a rapid screening to judge whether the DAN residues in milk exceed Maximum Residue Limits (MRLs) or not. 相似文献
74.
Verma Harshlata Mishra Kuldeep Rai D. K. 《Journal of Solid State Electrochemistry》2020,24(3):521-532
Journal of Solid State Electrochemistry - The paper reports effect of dispersion of titanium dioxide (TiO2) nanofiller on the sodium ion conducting nanocomposite polymer electrolyte membranes... 相似文献
75.
76.
Maheshwaran C. Kanchan D.K. Gohel Khushbu Mishra Kuldeep Kumar Deepak 《Journal of Solid State Electrochemistry》2020,24(3):655-665
Journal of Solid State Electrochemistry - In the present study, a magnesium ion conducting polymer electrolyte membrane system based on polyethylene oxide (PEO) containing magnesium triflate... 相似文献
77.
The present study demonstrates the interfacial interplay between transition metal salt (TMS) additive and range of non-aqueous lyotropic mesophases. Structural aspect reveals the substantial influence of the additive addition on the self-assembly and packing of micelles as intense growth of hexagonal planes was seen in the vicinity of the pre-existed lamellar mesophase (as the surfactant concentration loomed to the higher value in the parent binary mixture). Such structural modulations certainly resulted from reduction in optimal surface area of head group and packing parameter under the influence of interfacial interactions amid charged counter ions and metal salt additive. The origin and thermal stability of hexagonal ordering have been addressed and discussed. 相似文献
78.
Binary mixtures comprising cetylpyridinium chloride and non-aqueous solvents of varying polarity [ethylene glycol (ε ~ 37.2) and formamide (ε ~ 109)] were studied via X-ray diffraction, polarisation optical microscopy, differential scanning calorimetry and dielectric spectroscopy. Layered lamellar mesophase was observed in both mixtures. Formamide-based mesophase was found more ordered and stable up to higher temperature (140°C). Ordering and stability of the mesophase was explained considering the higher polarity and dipolar–dipolar interactions of formamide. Dielectric spectroscopy demonstrates the large magnitudes of capacitance and permittivity (Cp ≈ 9 µF and ε ≈ 2428) for mesophase derived from formamide. Dynamical relaxation parameters of both mixtures were discussed and correlated with their structural aspects. 相似文献
79.
This study highlights the effects of amphiphile chain length and counter ions on the self-assembly and dielectric behaviour of non-aqueous lyotropic liquid crystals. Two-dimensional hexagonal mesophase is seen for short-chain length sodium dodecyl sulphate, while lamellar and multiwall lamellar mesophases are noticed for long-chain length cetyltrimethylammonium bromide and polyoxyethylene (20) sorbitan monolaurate amphiphiles in the non-aqueous domains of ethylene glycol. A strong influence of amphiphile counter ions is seen on static dielectric constant, loss factor, relaxation frequency and relaxation time of these lyotropic mixtures. Refractive indices of these lyotropic phases are also highlighted. 相似文献
80.
Kuldeep Wadhwa Chengxi Yang Kris C. Deming Sanjay R. Chemburkar Rajarathnam E. Reddy 《合成通讯》2013,43(24):4434-4444
Abstract A variety of substituted arylglyoxylic acids (2a?g) were synthesized via oxidation of the corresponding aryl-methylketones (1a–e) using selenium dioxide or Friedel–Crafts acylation of phenol (3) with ethyl chlorooxoacetate and further transformations. It was found that the arylglyoxylic acids (2) undergo facile unimolecular dissociation with loss of carbon monoxide to give the corresponding arylcarboxylic acids (7) under collisionally induced mass spectrometric conditions. 相似文献