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101.
Background
Enzymes are often used in organic solvents for catalyzing organic synthesis. Two enzyme preparations, EPRP (enzyme precipitated and rinsed with n-propanol) and PCMC (protein coated microcrystals) show much higher activities than lyophilized powders in such systems. Both preparations involve precipitation by an organic solvent. The clear understanding of why these preparations show higher catalytic activity than lyophilized powders in organic solvents is not available. 相似文献102.
The charge transfer complexes of organic donors TTF and TMTSF have been prepared and studied with infrared spectroscopy. The
nature of transition has been studied by analyzing features of absorption. TTF-TCNQ was found to be a Peierls semiconductor
and not metallic. This shows that the mean field transition temperature is operative in TTF-TCNQ. TMTSF-TCNQ and TMTSF-DDQ
showed lesser band gap than that of TTF-TCNQ. TTF-DDQ and TTF-I2 also showed very small band gap and were more conducting than TTF-TCNQ. The band gaps could be assigned to either the Peierls
gap or the pinning gap of charge density waves. 相似文献
103.
Nirmal Prabhakar Pratima R. Solanki Ajeet Kaushik M. K. Pandey B. D. Malhotra 《Electroanalysis》2010,22(22):2672-2682
We have prepared nanocomposite films comprising of 3‐glycidoxypropyltrimethoxysilane (GOPS) and iron‐oxide (Fe3O4) onto indium‐tin‐oxide (ITO) glass plate for covalent immobilization of 21‐mer peptide nucleic acid (PNA). These films have been characterized using contact angle, atomic force microscopy (AFM), electrochemical techniques. The electrochemical response of the GOPS/ITO and Fe3O4‐GOPS/ITO electrodes has been investigated by hybridization with complementary, non‐complementary and one‐base mismatch using methylene blue as electrochemical indicator. The PNA/Fe3O4‐GOPS/ITO bioelectrode exhibits improved specificity and detection limit (0.1 fM) as compared to that of the PNA‐GOPS/ITO bioelectrode (0.1 pM). This PNA/Fe3O4‐GOPS/ITO electrode can be utilized for detection of hybridization with the complementary sequence in sonicated M. tuberculosis genomic DNA within 90 s of hybridization time. 相似文献
104.
Anjana Solanki Jaya Shrivastava Sumant Upadhyay Surbhi Choudhary Vidhika Sharma Poonam Sharma Pushpendra Kumar Praveen Kumar Sheryl Ehrman Vibha R. Satsangi Rohit Shrivastav Sahab Dass 《Current Applied Physics》2013,13(2):344-350
The effects of high electronic energy deposition on the structure, surface topography, optical property and photoelectrochemical behavior of barium titanate thin (BaTiO3) films have been investigated by irradiating films with 120 MeV Ag9+ ions at different ion fluences in the range of 1 × 1011–3 × 1012 ions cm?2. Barium titanate thin films were deposited on indium tin oxide-coated glass substrate by sol–gel spin coating method. The structure of the film was crystalline with tetragonal phase. Surface topography was studied by atomic force microscopy detailing the values of roughness of the films. Maximum photocurrent density of 1.78 mA cm?2 at 0.4 V/SCE and applied bias photon-to-current efficiency (ABPE) of 0.91% was observed for BaTiO3 film irradiated at 1 × 1011 ions cm?2. 相似文献
105.
Nd(OR')3, Nd(OR)(OR')2 and Nd(OR)2(OR') are prepared from neodymium isopropoxide and furfurylalcohol and tetrahydrofurfuryl alcohol in different stoichiometric ratios under reflux where OR=OPri or OBu'; OR'=deprotonated furfuryl and tetrahydrofurfuryl alcohol. Neodymium tertiary butoxide derivatives were prepared by alcohol exchange technique from the corresponding isopropoxide derivatives. The i.r. spectra of the alkoxy derivatives are discussed. 相似文献
106.
107.
In this study, heat transfer coefficients and pressure drops of R-134a inside round and flat tubes are investigated experimentally with mass flux of 450, 550, and 650 kg m?2 s?1 at saturation temperatures of 35°, 40°, and 45°C. The effects of mass flux and saturation temperature on heat transfer coefficient and pressure drop are examined. The maximum enhancement factor and pressure drop penalty are obtained by flat tube (FT-2) up to 2.101 at 450 kg m?2 s?1 and 3.01 at 650 kg m?2 s?1, respectively. The correlation for flat tubes is proposed to predict the heat transfer coefficient within ±20% error. 相似文献
108.
This paper describes the construction and operation of an air-coupled capacitance transducer with a conical backplate. This was designed to produce a focal region over an extended distance along the transducer axis. Measurements were performed to examine both the frequency response of the transducer in pulse-echo mode, and the lateral resolution for imaging purposes. The radiated field was measured and compared to theory, and the extent of the focal region determined. Images of surface topography are presented, to illustrate the range of application of the transducer. 相似文献
109.
We report calculations of extremal areas of four Fermi surface (FS) orbits of the noble metals using the linear muffin tin
orbital method in the atomic sphere approximation. Our calculations indicate that thel = 3 potential parameters and increase in the number of k-points in the Brillouin zone (BZ) summation from 240 to 916 have
no significant effect on the FS. All calculations were performed self-consistently including up tol = 2 potential parameters and with 240 k points in the BZ summation. Calculations were performed with the exchange, correlation
potentials (XCP) of Barth-Hedin, Barth-Hedin modified by Janak, SlaterX
α, and the Vosko-Wilk-Nussair. Results compared with other theoretical calculations indicate that none of the above XC potentials
give an accurate representation of the FS for all the noble metals. We feel that the inclusion of the non-locality of XCP
may give a better account of the FS geometry. 相似文献
110.
The synthesis of lanthanide amido complexes of the type Ln(CH3CONR)3 (I), (OPri)Ln(C6H5CONC6H5)2 (II), and (OBut)Ln(C6H5CONC6H5)2 (III) [where Ln = La, Pr, Nd; R = C6H5, p-NO2C6H4, p-BrC6H4] are described. Infrared spectra indicate deprotonation of the secondary amide (anilide). Anion coordination is proposed as chelating bidenate ligands. 相似文献