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21.
Zanardi J Lamazure D Minière S Reboul V Metzner P 《The Journal of organic chemistry》2002,67(25):9083-9086
Asymmetric allylidenation of aldehydes with sulfur ylides is possible with proper substitution of the initial sulfide, to avoid the [2,3] sigmatropic rearrangement of the unsaturated ylides. One-pot reaction of (2R,5R)-dimethylthiolane with allyl halides, aldehydes, and sodium hydroxide in tert-butyl alcohol affords vinyl oxiranes in good yields. Enantiomeric excesses up to 90% and trans selectivities have been achieved with methallyl-type halides. 相似文献
22.
Dragica M. Minić Maja T. Šumar-Ristović Đenana U. Miodragović Katarina K. Anđelković Dejan Poleti 《Journal of Thermal Analysis and Calorimetry》2012,107(3):1167-1176
The kinetics of multi-step thermal degradation of Co(II) complex with N-benzyloxycarbonyl glycinato ligand [Co(N-Boc-gly)2(H2O)4]·2H2O, in non-isothermal conditions was studied using isoconversional and non-isoconversional methods. The degradation of complex
occurs in three well-separated steps involving the loss of water molecules in first step followed by two degradation steps
of dehydrated complex. The dependence of Arrhenius parameters on conversion degree showed that all observed steps of thermal
degradation are very complex, involving more than one elementary step, as can be expected for most solid-state heterogeneous
reactions with solid reactants and solid and gaseous products. It was shown that step 1, corresponding to the dehydration,
involves a series of competitive dehydration steps of differently bound water molecules complicated by diffusion. Second step
involves two parallel reactions related to the loss of two identical C6H5CH2O– ligand fragments complicated by the presence of products in gaseous state. Further degradation in step 3 corresponds to
complex process with a change in the limiting stage, in this case from the kinetic to the diffusion regime, connected with
the presence of gaseous products diffusing through the solid product. 相似文献
23.
24.
Machado Md.V. Goussevskaia O. Mini R.A.F. Rezende C.G. Loureiro A.A.F. Mateus G.R. Nogueira J.M.S. 《Selected Areas in Communications, IEEE Journal on》2005,23(12):2305-2319
In this paper, a new data dissemination algorithm for wireless sensor networks is presented. The key idea of the proposed solution is to combine concepts presented in trajectory-based forwarding with the information provided by the energy map of the network to determine routes in a dynamic fashion, according to the energy level of the sensor nodes. This is an important feature of an autonomic system, which must have the capacity of adapting its behavior according to its available resources. Simulation results revealed that the energy spent with the data dissemination activity can be concentrated on nodes with high-energy reserves, whereas low-energy nodes can use their energy only to perform sensing activity or to receive information addressed to them. In this manner, partitions of the network due to nodes that ran out of energy can be significantly delayed and the network lifetime extended. 相似文献
25.
D. M. Minić I. Cekić F. T. Pastor V. Jovanović R. Marković 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(9):1458-1462
This study demonstrates the electrochemical activity of selected 2-alkylidene-4-oxothiazolidine compounds containing different
substituents at the C5-position on the Pt-electrode in 0.1 M TBAHFP + MeCN in the potential range from −2 V to 2 V. The mechanism
of electrode processes is discussed. It is shown that a chemical step is involved in irreversible electrochemical processes.
The effect of the substituent at the C5-position on reduction and oxidation potentials is also noted. The regions of a linear
dependence of the current peak on the concentration of the compounds examined are determined.
The text was submitted by the authors in English. 相似文献
26.
M Perrot F Sagliocco T Mini C Monribot U Schneider A Shevchenko M Mann P Jen? H Boucherie 《Electrophoresis》1999,20(11):2280-2298
By proving the opportunity to visualize several hundred proteins at a time, two-dimensional (2-D) gel electrophoresis is an important tool for proteome research. In order to take advantage of the full potential of this technique for yeast studies, we have undertaken a systematic identification of yeast proteins resolved by this technique. We report here the identification of 92 novel protein spots on the yeast 2-D protein map. These identifications extend the number of protein spots identified on our yeast reference map to 401. These spots correspond to the products of 279 different genes. They have been essentially identified by three methods: gene overexpression, amino acid composition and mass spectrometry. These data can be accessed on the Yeast Protein Map server (htpp://www.ibgc.u-bordeaux2.fr/YPM). 相似文献
27.
N. Petranović D. Minić T. J. Sabo D. Doković 《Journal of Thermal Analysis and Calorimetry》2000,59(3):807-814
Thermal properties of facial and meridional uns-cis-[Co(eddp)gly]0.5H2O complexes were investigated by means of DSC and TG techniques. It wasshown that the processes of thermal decomposition of
these complexes are multi-stepdegradation processes, which can also be well separated into individual steps, depending onthe
molecular symmetry. Thus, the process of thermal degradation of the meridional isomerof the above complex consists of 4 well-separated
steps in the temperature interval from 100to 500°C. The corresponding kinetic and thermodynamic parameters of this process
weredetermined, and a possible mechanism is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
28.
The thermal stability of push-pull 5-substituted-4-oxothiazolidines was studied by DSC, IC and X-ray diffraction techniques.
It was shown that the compounds are stable in the temperature range from room temperature to melting point. The melting is
combined with breaking crystal structure and forming glass material as a new phase that forms crystals by cooling it very
slowly. The rate constant, activation energy as well as activation parameters of process were determined. 相似文献
29.
30.
Free space optics (FSO) link at high transmission rate is delimited due to its perceptivity to diversified surroundings especially in hilly regions. A demonstration of CDMA-FSO coherent detection system is reported in this work to achieve a prolonged 10 Gbps-FSO link with acceptable SNR under the impact profound haze, rain and fog environment. Further, the work is extended to weigh the proposed CO-CDMA-OSSB-FSO transmission system against OFDM-OSSB-FSO direct detection system 0045 and 0050. 相似文献