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1.
Structural Chemistry - The hydrogen bond interactions between methyl-imidazolium cation (MIM+) and fatty acid anions (CmHnCOO–, where m?=?1–6; n-3–13) of ionic liquids... 相似文献
2.
An M/G/1 retrial queueing system with additional phase of service and possible preemptive resume service discipline is considered. For an arbitrarily distributed retrial time distribution, the necessary and sufficient condition for the system stability is obtained, assuming that only the customer at the head of the orbit has priority access to the server. The steady-state distributions of the server state and the number of customers in the orbit are obtained along with other performance measures. The effects of various parameters on the system performance are analysed numerically. A general decomposition law for this retrial queueing system is established. 相似文献
3.
V. Bena Jothy T. Vijayakumar D. Sajan V. S. Jayakumar I. Hubert Joe 《Laser Physics》2006,16(8):1242-1252
Single crystals of sarcosinium oxalate monohydrate (SOM) are grown by the slow-evaporation technique at ambient temperature, and vibrational spectroscopic analysis is carried out using NIR-FT Raman, FT-IR, and SERS spectra. The normal mode frequencies and corresponding vibrational analysis of SOM are examined theoretically using the Gaussian’98 set of quantum chemical codes. The two bands present in the SOM ν C=O region, clearly observed in the Raman spectrum, are assigned to “free” and “bonded” carbonyl groups with the hydrogen atom. Vibrational analysis indicates the presence of C-H—O hydrogen bonding interaction producing a blueshift of the C-H stretching frequency. 相似文献
4.
The title compound is a centrosymmetric dimer with each cadmium in a distorted CdS5 square pyramidal geometry. The Cd–S bond distances range from 2.5626(11) to 2.8459(11) Å. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
5.
An age-dependent branching process where disasters occur as a renewal process leading to annihilation or survival ofall the cells, is considered. For such a process, the total mean sojourn time of all the cells in the system is analysed using the regeneration point technique. The mean number of cells which die in timet and its asymptotic behaviour are discussed. When the disasters arrival as a Poisson process and the lifetime of the cells follows exponential distribution, elegant inter-relationships are found among the means of (i) the total number of cells which die in timet (ii) the total sojourn time of all cells in the system upto timet and (iii) the number of living cells at timet. Some of the existing results are deduced as special cases for related processes. 相似文献
6.
In this paper, a conjecture of G.J. Chang, that d(C(G)) ≤2 for any connected chordal graphG withd(G) = 2r(G) - 2, is disproved. 相似文献
7.
Sheik A. Samath Kadarkaraithangam Jeyasubramanian Subramanian Thambidurai Sickandar Kamardeen Sutharavalli K. Ramalingam 《Transition Metal Chemistry》1994,19(2):157-159
Summary Several bis/tris-salicylaldehyde, salicylaldimine and salicyalethylenediimine chelates of cobalt(III), chromium(III), cobalt(II), nickel(II)
and copper(II) readily react with various brominating agents and undergo α-bromo/cyano/succinimido substitution, with or without
accompanying bromine substitution of the aryl ring. The selectivity of these reactions on the metal-coordinated salicylaldehyde
derivatives allows the preparation in 50–80% yield of hitherto unreported specific α-bromo products. The substituted organic
compounds could be isolated by demetallation of the chelate products. 相似文献
8.
A simple and fast complexometric method for the determination of tin in alloys is presented. It is based on the initial complexation of tin with EDTA and its subsequent decomposition with mercaptosuccinic acid. Interference of ions normally encountered in determination of tin was studied. The method has been used for the analysis of alloys such as bronzes, solders, white metal and titanium base alloys. 相似文献
9.
Samath S. Abdul Raman Mani Raman Natarajan Jeyasubramanian Kadarkarai Thangam Ramalingam Suthamalli K. 《Transition Metal Chemistry》1992,17(1):13-15
Transition Metal Chemistry - The synthesis and structural characterization of new metal(II) chelates (M = CoII, NiII, CuII and ZnII) of neutral conjugated bidentate β-diketone ligands, having... 相似文献
10.
The products of pyrolysis, at 400°C in vacuo (1 Pa), of poly(ethyleneterephthalate) (PET) and poly(butyleneterephthalate) (PBT) were studied. The products were identified by gas chromatography/mass spectrometry technique. The highly volatile products of PET contained acetaldehyde, benzene, toluene, styrene and ethylbenzene and in the case of PBT, butadiene, tetrahydrofuran, vinylcyclohexene and ethylbenzene were the major products. A qualitative analysis of the products of low volatility revealed that the main components were benzoic acid, terephthalic acid, monovinyl esters of terephthalic acid and higher oligomers in the case of PET, whereas benzoic acid, monobutenyl esters of terephthalic acid and higher oligomers were the main products from PBT. The results obtained were in good agreement with those obtained from pyrolysis experiments, carried out directly in the mass spectrometer. Mechanisms to explain the occurrence of the different products are proposed. 相似文献