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991.
Ángel Piñeiro Pilar Brocos Alfredo Amigo Mercedes Pintos Ramón Bravo 《Journal of solution chemistry》2002,31(5):369-380
Refractive indexes at 25°C were measured for binary mixtures of tetrahydrofuran with 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol. Densities, from which excess molar volumes were derived, were measured at the same temperature for the system tetrahydrofuran + 1-decanol. Refractive indexes and densities for the pure compounds were determined at 11 temperatures between 20 and 30°C. The thermal expansion coefficients and the temperature derivatives of the refractive index for these liquids were calculated at 25°C. The temperature dependence of the molar refraction was also examined. The contribution to the molar refraction of a CH2 group was calculated as was the difference between contributions from CH3 and CH2OH groups. The change of molar refraction on mixing is d iscussed in terms of molecular interactions and alkyl chain length. 相似文献
992.
993.
994.
Ram K Tripathi 《Pramana》1977,8(5):471-477
Bethe-Faddeev wave functions are generalized toN-body clusters. A comparison made between the Bethe approximation and the Day approximation in the three body cluster indicates
that the two approximations should be competitive for the higher body clusters. 相似文献
995.
The object of the present investigation is to study the anisotropic propagation of weak discontinuities in flows of thermally conducting and dissociating gases. The velocity of propagation of the wave frcnt is determined. A set of differential equations governing the growth and decay of weak discontinuities are obtained and solved. It is found that if the sonic wave is a compressive wave of order 1, then it terminates into a shock wave after a critical timet c which has been determined. It is also observed that the effects of heat conduction and dissociation are to decrease the duration of time by which a weak discontinuity will generate into a shock wave. 相似文献
996.
997.
M.O. Ramírez J.J. Romero P. Molina L.E. Bausá 《Applied physics. B, Lasers and optics》2005,81(6):827-830
Tunable laser action from a diode pumped Nd3+ activated SrxBa1-x(NbO3)2 crystal has been obtained. A wide continuous tuning range of 43 nm in the near infrared region (1050–1093 nm) has been demonstrated
due to the broad 4F3/2→4I11/2 emission band present in this system. Simultaneously, 20 nm of tunability in the green region (525–545 nm), as well as 7 nm
in the blue one (455–462 nm) have been achieved by tunable self-frequency conversion processes using the quasiphase matching
technique, without any angle or thermal tuning of the laser crystal. The results evidence that the system is a reliable candidate
for compact tunable coherent devices based on diode pumped Nd3+ active ions, which are of interest in many technological and scientific applications.
PACS 77.84.Dy; 42.79.Nv; 42.60.Fc; 42.55. Xi 相似文献
998.
Ajay K Bose Maghar S Manhas Shanti G Amin Jagdish C Kapur J Kreder L Mukkavilli Bhagat Ram John E Vincent 《Tetrahedron letters》1979,20(30):2771-2774
The reaction of a Schiff Base derived from veratrylamine and cinnamaldehyde with (α-methyl-β-alkoxycarbonyl)-vinylamino acetic acid (from glycine and an acetoacetate ester) in presence of a chloroformate ester and triethylamine constitutes a safe synthesis of α-vinylamino β-lactams that can be converted by literature methods to known intermediates for the synthesis of isocephalosporins and analogs. 相似文献
999.
Inside Back Cover: Infinite Polyiodide Chains in the Pyrroloperylene–Iodine Complex: Insights into the Starch–Iodine and Perylene–Iodine Complexes (Angew. Chem. Int. Ed. 28/2016)
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1000.
Patrícia Matias José Manuel Lopes Sébastien Laforge Patrick Magnoux Michel Guisnet Fernando Ram?a Ribeiro 《Reaction Kinetics and Catalysis Letters》2008,95(1):193-201
The main features of methylcyclohexane (mch) and n-heptane (n-C7) transformation at 350°C were compared for fresh samples of HMWW, HMFI and HFAU zeolites. With both reactions, the behavior
of HMWW was between those of the medium HMFI and large pore HFAU zeolites. Thus, the values of turnover frequency (TOF) and
of the TOFmch/n-C7 ratio were similar with HMWW and HMFI and much higher with HFAU. In contrast, small differences were found between product
distributions over HMWW and HFAU but large differences between HMWW and HMFI. These observations can be explained by alkane
transformation in the large supercages with 10-MR apertures of HMWW: the narrow apertures limit diffusion of the mch within
the supercages, but not the diffusion of the products which are therefore typical of the transformation within large cages
hence without any steric limitation. 相似文献