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71.
K. P. O. Mahesh Y. Tsujita H. Yoshimizu S. Okamoto D. Mohan 《Journal of Polymer Science.Polymer Physics》2005,43(17):2380-2387
The syndiotactic polystyrene (sPS) δ form was crystallized from mixtures with different compositions of p‐chlorotoluene–chlorobenzene (p‐CT–CB) and p‐chlorotoluene–1,1,2‐trichloroethane (p‐CT–TCE). The presence of the δ form and TTGG helical conformation was confirmed by Fourier transform infrared and wide‐angle X‐ray diffraction (WAXD) analyses. In sPS/p‐CT–CB and sPS/p‐CT–TCE δ‐form membranes, the relative absorbance (RA) of the p‐chlorotoluene (p‐CT) solvent peak was very high even at very low concentrations of p‐CT in comparison with the RA of higher concentrations of chlorobenzene (CB) or 1,1,2‐trichloroethane (TCE) in the mixtures. However, the RAs of both CB and TCE solvent peaks decreased with decreasing concentrations of CB and TCE in the mixtures. A negligible decrease in the RA of the TTGG helical content was observed with a decreasing concentration of CB or TCE. The WAXD results showed that the 2θ peak positions of the [010] and [ 10] planes of the sPS/p‐CT–CB and sPS/p‐CT–TCE δ‐form membranes appeared in the same position and were almost equal to those of the sPS–p‐CT δ‐form membrane. The mesophases of the sPS–p‐CT [p‐CT (A‐M)] and sPS–TCE [TCE (A‐M)] membranes were used for the sorption studies with different concentrations of various solvents. The sorption amount of aromatic solvents by both p‐CT (A‐M) and TCE (A‐M) mesophase membranes was higher than that of aliphatic solvents, regardless of the size, shape, and nature of the molecular cavity. The 2θ peak of the [010] plane of the sPS membranes slowly approached the original δ‐form value when the sPS mesophase membranes were immersed in various solvents of different concentrations for 48 h. The shifting of the 2θ peak of the [010] plane to the original δ form depended on the nature and concentration of the immersion solvents. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2380–2387, 2005 相似文献
72.
Production of ethanol from cellulosic biomass by Clostridium thermocellum SS19 in submerged fermentation 总被引:1,自引:0,他引:1
Carotenogenesis of the lactose-negative yeast Rhodotorula rubra GED5 was studied by cocultivation with Kluyveromyces lactis MP11 in whey ultrafiltrate (WU) (35, 50, and 70 g of lactose/L). Maximum yields of cell mass (24.3 g/L) and carotenoids (10.2
mg/L of culture fluid or 0.421 μ g/g of dry cells) were obtained by growing the microbial association in WU (50 g of lactose/L)
in a fermentor with an airflow rate of 0.8 L/(L·min), agitation of 220 rpm, and temperature of 30°C. The identified carotenoid
pigments—β-carotene, torulene, and torularhodin—reached maximum concentrations (133, 26.9, and 222.3 μg/g of dry cells, respectively)
on d 5 for torulene and d 6 for β-carotene and torularhodin. 相似文献
73.
Ligand location within particles, detected by immunogold labelling, was shown to influence the biochemical productivity of a silica-based solid phase, Sorbsil C-500, using a model ligand-biomolecule system (immobilised human immunoglobulin G-anti-human immunoglobulin G monoclonal antibody). The distribution of the ligand was in turn affected by the initial ligand challenge used to prepare the immunoadsorbents. Maximal productivity was achieved with adsorbents prepared with an initial challenge of about 3 mg human immunoglobulin G per ml: the ligand in these cases was shown to be more uniformally distributed within the adsorbent particles than adsorbents, exhibiting low productivity, prepared with either low (1 mg/ml) or high (9 mg/ml) concentrations of human immunoglobulin G. The ligand in the latter was restricted to the periphery of the particles. 相似文献
74.
Alex. G. Harrison R. Krishna Mohan Rao Kallury 《Journal of mass spectrometry : JMS》1980,15(5):249-256
A study of the electron impact and chemical ionization (H2, CH4, and iso-C4H10) mass spectra of stereoisomeric benzoin oximes and phenylhydrazones indicates that while the former can be distinguished only by their chemical ionization mass spectra the latter are readily distinguishable by both their electron impact and chemical ionization mass spectra. The electron impact mass spectra of the isomeric oximes are practically identical; however, the chemical ionization spectra show that the E isomer forms more stable [MH]+ and [MH? H2O]+ ions than the Z isomer for which both the [MH]+ and [MH? H2O]+ ions are relatively unstable. In electron impact the Z-phenylhydrazone shows a lower [M]+˙ ion abundance and more facile loss of H2O than does the E isomer. This more facile H2O loss also is observed for the [MH]+ ion of the Z isomer under chemical ionization conditions. 相似文献
75.
The effect of impurities on the growth of manganese carbonate crystals has been studied. Stereophotogrammetric analysis showed
that all crystal faces have the same Miller indices
and the peanut-shaped forms are twins with twin axis 0001. 相似文献
76.
77.
Venkatanarayana Pappula Ramachandra Reddy DonthiriChandra Mohan Darapaneni Adimurthy Subbarayappa 《Tetrahedron letters》2014
Synthesis of β-bromostyrenes from styrene bromohydrins using H-β-zeolite as catalyst under moderate conditions is reported. The catalyst could be regenerated and reused up to three consecutive cycles. 相似文献
78.
Dhananjaya Patra Mohan Ramesh Duryodhan Sahu Harihara Padhy Chih‐Wei Chu Kung‐Hwa Wei Hong‐Cheu Lin 《Journal of polymer science. Part A, Polymer chemistry》2012,50(5):967-975
A conjugated main‐chain copolymer ( PBT ) consisting of bithiazole, dithieno[3,2‐b:2′,3′‐d]pyrroles (DTP), and pendent melamine units was synthesized by Stille polymerization, which can be hydrogen‐bonded (H‐bonded) with proper molar amounts of bi‐functional π‐conjugated crosslinker F (i.e., two uracil motifs covalently attached to a fluorene core through triple bonds symmetrically) to develop a novel supramolecular polymer network ( PBT/F ). The effects of multiple H‐bonds on light harvesting capabilities, HOMO levels, and photovoltaic properties of polymer PBT and H‐bonded polymer network PBT/F are investigated. The formation of supramolecular polymer network ( PBT/F ) between PBT and F was confirmed by FTIR and XRD measurements. Because of the stronger light absorption, lower HOMO level, and higher crystallinity of H‐bonded polymer network PBT/F , the solar cell device containing PBT/F showed better photovoltaic properties than that containing polymer PBT . The preliminary results show that the solar cell device containing 1:1 weight ratio of PBT/F and [6,6]‐phenyl C71 butyric acid methyl ester (PC71BM) offers the best power conversion efficiency (PCE) value of 0.86% with a short‐circuit current density (Jsc) of 4.97 mA/cm2, an open circuit voltage (Voc) of 0.55 V, and a fill factor (FF) of 31.5%. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
79.
Balakrishna Kolli Sarada P. Mishra M. P. Joshi S. Raj Mohan T. S. Dhami A. B. Samui 《Journal of polymer science. Part A, Polymer chemistry》2012,50(8):1572-1578
Four linear polymers containing pendant azo moiety were synthesized through click chemistry for second‐order nonlinear optical study. The polymers were found soluble in most of the polar organic solvents such as tetrahydrofuran (THF), chloroform, and dimethyl formamide (DMF). The polymers showed thermal stability up to 300 °C and glass transition temperatures (Tg) in the range of 120–140 °C. The molecular weights (Mw) of these polymers (measured by gel permeation chromatography) were in the range 37,900–55,000 g/mol. The polymers were found to form optically transparent films by solution casting from THF solution. Order parameters were calculated from UV–vis absorption spectra. The morphology changes in the films after poling were characterized by atomic force microscopy. The angular dependence, temperature dependence, and time dependence of second harmonic generation (SHG) intensity were obtained by using 1064 nm Nd:YAG laser. The SHG intensity remained unchanged up to 95 °C. At room temperature, it remained stable up to 8 days after initial drop of about 14%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
80.
Varadhan Krishnakumar Kesarla Mohan Kumar Badal Kumar Mandal Fazlur-Rahman Nawaz Khan 《Research on Chemical Intermediates》2012,38(8):1881-1892
A simple and green protocol, developed utilizing an efficient, heterogeneous and recyclable catalyst, i.e. zinc oxide nanoparticles (ZnO NPs)-mediated synthesis of N-arylhomophthalimides and benzannelated isoquinolinones, is reported. The structures of the desired products were characterized by FTIR, 1H NMR, 13C NMR, and HRMS techniques. The ZnO NPs exhibited excellent catalytic activity and the proposed methodology is capable of providing the desired products in good yield and purity. 相似文献