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71.
72.
Non-aqueous polymer gel electrolytes containing trifluoromethanesulfonic acid (HCF3SO3) and polyethylene oxide (PEO) as the gelling polymer has been studied. The increase in conductivity observed with the addition
of PEO to liquid electrolytes has been explained to be due to the breaking of ion aggregates present in electrolytes at higher
acid concentrations. The increase in free H+ ion concentration upon breaking of ion aggregates has also been observed in pH measurements and viscosity of gel electrolytes
has been found to increase with PEO addition. Polymer gel electrolytes containing dimethylacetamide (DMA) have σ ∼ 10−2 S/cm at room temperature and are stable over −50 to 125 °C range of temperature. Gels based on propylene carbonate (PC) and
ethylene carbonate (EC) are stable in the −50 to 40 °C temperature range and loose their gelling nature above 40 °C. 相似文献
73.
JPC – Journal of Planar Chromatography – Modern TLC - The sorption behavior of a number of metal ions was investigated on thiourea-impregnated silica gel G and alumina layers with... 相似文献
74.
Uma Sharma Rajiv R. Singh Vineet Ahuja Govind K. Makharia Naranamangalam R. Jagannathan 《Magnetic resonance imaging》2010
Background
The histological extent of inflammatory bowel disease (IBD) is greater than that evident by colonoscopic evaluation. We hypothesized that metabolic profile in macroscopically un-involved colonic mucosa in IBD is similar to that of controls with healthy colon. We thus assessed the differences in metabolic profile in macroscopically involved and un-involved colonic mucosa of IBD patients to further substantiate the extent of disease.Patients and Methods
Colonic mucosal biopsies were obtained and snap frozen from both the macroscopically un-involved and involved colonic mucosa of IBD patients and macroscopically normal colonic mucosa of controls and were subjected to in-vitro high-resolution proton (1H) magnetic resonance (MR) spectroscopy and the concentrations of metabolites were determined.Results
Thirty-two metabolites were assigned in the proton MR spectrum of colonic mucosa of IBD patients. The concentrations of amino acids (isoleucine, leucine, valine, arginine, lysine, glutamine/glutamate, alanine), membrane metabolites (choline, glycerophosphorylcholine/phosphorylcholine), glycolytic product (lactate) and short chain fatty acid (formate) were significantly lower while significantly high level of glucose were observed in the macroscopically un-involved colonic mucosa of IBD patients compared to the macroscopically normal mucosa of controls. There was no significant difference in the concentrations of metabolites in macroscopically involved and un-involved colonic mucosa of IBD patients.Conclusions
The metabolic profile in macroscopically un-involved colonic mucosa of IBD patients is similar to that of macroscopically involved mucosa but different from colonic mucosa of controls. This suggests that even macroscopically un-involved colonic mucosa is metabolically abnormal and may explain the increase in extent of disease with time. 相似文献75.
76.
Ganapathy S Gore KU Kumar R Amoureux JP 《Solid state nuclear magnetic resonance》2003,24(2-3):184-195
Multinuclear solid-state NMR spectroscopy, employing 29Si MAS,27Al MAS/3Q-MAS and (47,49)Ti wide-line experiments, has been used for the structural characterization of titanium substituted ultra-stable zeolite Y (Ti-USY). 27Al MAS experiments show the presence of aluminum in four (Al(IV)), five (Al(V)), and six (Al(VI)) coordination, whereas the multiplicity within Al(IV) and Al(VI) is revealed by 27Al 3Q-MAS experiments. Two different tetrahedral and octahedral Al environments are resolved and their isotropic chemical shifts (delta(CS)) and second-order quadrupole interaction parameters (P(Q)) have been determined by a graphical analysis of the 3Q-MAS spectra. The emergence of signal with higher intensity at -101 ppm in the 29Si MAS spectrum of Ti-USY samples indicates the possible occurrence of Q4(3Si,1Ti) type silicon environments due to titanium substitution in the faujasite framework. High-field (11.74T) operation, using a probehead specially designed to handle a large sample volume, has enabled the acquisition of 47,49Ti static spectra and identification of the titanium environment in the zeolite. The chemical shielding and electric field gradient tensors for the titanium environment in the zeolite have been determined by a computer simulation of the quadrupolar broadened static 47,49Ti NMR spectra. 相似文献
77.
Rajiv?Vaidya Madhavi?Dave S.?S.?Patel S.?G.?PatelEmail author A.?R.?Jani 《Pramana》2004,63(3):611-616
In the present paper an attempt has been made to describe the chemical vapor transport (CVT) technique used for the growth
of molybdenum disulphide (MoS2) single crystals. Iodine (I2) is used as transporting material for this purpose. The energy dispersive analysis by X-ray (EDAX) confirmed the stoichiometry
of the as-grown crystals. The lattice parameters of these crystals were determined from the X-ray diffraction analysis. The
grown crystals were examined under the optical zoom microscope for their surface microstructure study. 相似文献
78.
Ganapathy S Kumar R Delevoye L Amoureux JP 《Chemical communications (Cambridge, England)》2003,(16):2076-2077
[27Al]-1H REAPDOR (Rotational Echo Adiabatic Passage DOuble Resonance) NMR experiments distinguish structurally dissimilar Br?nsted acid sites located in main 8 and 12 membered-ring channels of the zeolite mordenite. 相似文献
79.
Yu Chen Hengchang Guo Wei Gong Luye Qin Hossein Aleyasin Rajiv R Ratan Sunghee Cho Jianxin Chen Shusen Xie 《中国光学快报(英文版)》2013,(1):59-66
In the past two decades, two-photon microscopy (TPM) transforms biomedicalresearch, allowing nondestructive high-resolution fluorescent molecular imaging and label-free imaging in vivo and in real time. Here we review the recent advances of TPM technologyincluding novel laser sources, new image acquisition paradiams, and microendoscopicimaging systems. Then, we survey the capabilities of TPM imagingof biological relevant molecules such as nicotinamideadenine dinucleotide (NADH), flavin adenine dinucleotide (FAD),and reactive oxygen species (ROS). Biomedical applications of TPM in neuroscience and cancer detection are demonstrated. 相似文献
80.
Transition metal dichalcogenides, because of their layered structure, are well suited for extreme pressure lubrication. These materials being semiconducting and of layered structure may undergo structural and electronic transitions under pressure. Here we report the details of the preparation and characterization of single crystals of NbTe2 and the results of electrical resistance measurements under pressure carried out on it to investigate this possibility. Single crystals were grown by the chemical vapor transport technique, using iodine as a transporting agent. The composition of the grown crystals was confirmed on the basis of Energy Dispersive Analysis by X-ray (EDAX) and remaining structural characterization was also accomplished by X-ray Diffraction (XRD) studies. Electrical resistance was measured employing a Bridgman anvil set up to 10?GPa and diamond anvil cell (DAC) assembly up to 25?GPa. A technique slightly modified from that described in the literature for carrying out electrical resistivity measurements in the diamond anvil cell (DAC) under pressure has been standardized. 相似文献