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101.
Rotich M. K. Brown M. E. Glass B. D. 《Journal of Thermal Analysis and Calorimetry》2003,73(2):671-686
The thermal behaviour of benzoic and salicylic acids is compared with the behaviour of 1:1 molar ratio physical and kneaded
mixtures of these acids with each of three different cyclodextrins (b-, hydroxypropyl-b-, and g-cyclodextrin). Differential
scanning calorimetry and thermogravimetry coupled with evolved gas analysis by Fourier transform infrared spectroscopy were
used for the thermal studies and X-ray powder diffraction and infrared spectroscopy provided complementary information. Thermal
studies of benzoic acid with the cyclodextrins showed significant interactions in both physical and kneaded mixtures of benzoic
acid/b-cyclodextrin and benzoic acid/hydroxypropyl-b-cyclodextrin. Interactions in the kneaded benzoic acid/g-cyclodextrin
mixtures were the most extensive as might be expected for the cyclodextrin with the largest molecular cavity. The results
for the salicylic acid/b-cyclodextrin and salicylic acid/hydroxypropyl-b-cyclodextrin mixtures were similar to those for benzoic
acid/b-cyclodextrin and benzoic acid/hydroxypropyl-b-cyclodextrin. Again, the kneaded salicylic acid/g-cyclodextrin mixture
showed the most interaction.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
102.
103.
Laminar boundary layer flows behind constant speed shock waves moving into a dusty gas are analyzed numerically. The basic equations of two-phase flows are derived in shock fixed coordinates and solved by an implicit finite-difference method for the side wall boundary layer in a dusty gas shock tube. The development of the boundary layer and resulting velocity and temperature profiles, respectively, for the gas and particles are given from the shock front to far downstream. The effects of diaphragm pressure ratio, mass loading ratio of particles and particle size upon the flow properties are discussed in detail.This article was processed using Springer-Verlag TEX Shock Waves macro package 1990. 相似文献
104.
Block E Dikarev EV Glass RS Jin J Li B Li X Zhang SZ 《Journal of the American Chemical Society》2006,128(46):14949-14961
More than 40 new 4- to 12-membered ring heterocycles containing various combinations of Group 14 and 16 elements Si, Sn, S, Se, and Te have been synthesized and fully characterized. Synthesis of these small-ring as well as medium-ring (mesocyclic) heterocycles from alpha,omega-dihalides is facilitated by the presence of gem-dialkylsilyl and gem-dialkylstannyl groups in the precursors. Conformations of several of the new ring systems in the solid state have been determined by X-ray crystal structure analysis. Oxidation of mixed S(Se, Te)/Si eight-membered ring mesocycles with NOPF6 or Br2 gives dications or a bicyclic dibromide, respectively, which can be characterized by NMR methods. On treatment with nucleophiles, mesocyclic dications, or the corresponding radical cations undergo ring contraction, giving five- or six-membered ring heterocycles. Photolysis of a S/Se four-membered ring heterocycle gives selenoformaldehyde, trapped in 80% yield with 2,3-dimethyl-1,3-butadiene. 相似文献
105.
V. V. Bludov A. M. W. Glass 《Transactions of the American Mathematical Society》2006,358(12):5179-5192
In 1974, J. Martinez introduced the variety of weakly Abelian lattice-ordered groups; it is defined by the identity
106.
Leitch MJ Boissevain J Carey TA Jansen DM Jeppesen RG Kapustinsky JS Lane DW Lillberg JW McGaughey PL Moss JM Peng JC Isenhower LD Sadler ME Schnathorst R Gidal G Ho PM Kowitt MS Luk KB Pripstein D Lederman LM Schub MH Brown CN Cooper WE Glass HD Gounder KN Mishra CS Kaplan DM Luebke WR Martin VM Preston RS Sa J Tanikella V Childers R Darden CW Wilson JR Chen YC Kiang GC Teng PK 《Physical review letters》1994,72(16):2542-2545
107.
108.
The rates of relaxation of HCl(ν = 1) and DCl(ν = 1) by atomic oxygen have been determined between 196 and 400 K using the laser induced vibrational fluorescence method. The values of the rate constants, κ1,H and κ1,D, can be matched quite well by Arrhenius expressions: κ1,H = 6.2 × 10?12 exp (?1.05 kcal mole?1/RT) cm3 molecule?1 s?1 and κ1,D = 2.9 × 10?12 exp (?0.5 kcal mole?1/RT) cm3 molecule?1 s?1. The most likely explanation of the absolute and relative magnitudes of these rate constants appears to be that relaxation occurs as a result of non-adiabatic vibronic transitions during collisions. 相似文献
109.
Vitreous Pb5Ge3O11 was prepared by water quenching and by roller quenching. The crystallization was studied by DTA, X-ray diffraction, and TEM. After a glass transition at 325°C, meta-stable Pb5Ge3O11 crystallized exothermically at 370°C. This was subsequently followed by the formation of the stable phase of the same composition, again exothermically at 490°C. 相似文献
110.