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101.
Thermal behaviour of nickel amine complexes containing SO4
2−, NO3
−, Cl− and Br− as counter ions and ammonia and ethylenediamine as ligands have been investigated using simultaneous TG/DTA coupled with
mass spectroscopy (TG/DTA–MS). Evolved gas analyses detected various transient intermediates during thermal decomposition.
The nickel ammonium sulphate complex produces NH, N, S, O and N2 species. The nickel ammonium nitrate complex generated fragments like N, N2, NO, O2, N2O, NH2 and NH. The halide complexes produce NH2, NH, N2 and H2 species during decomposition. The ligand ethylenediamine is fragmented as N2/C2H4, NH3 and H2. The residue hexaamminenickel(II) sulphate produces NiO with crystallite size 50 nm. Hexaammine and tris(ethylenediamine)nickel(II)
nitrate produce NiO in the range 25.5 nm and 23 nm, respectively. The halide complexes produce nano sized metallic nickel
(20 nm) as the residue. Among the complexes studied, the nitrate containing complexes undergo simultaneous oxidation and reduction. 相似文献
102.
Vangal S. Anders M.A. Borkar N. Seligman E. Govindarajulu V. Erraguntla V. Wilson H. Pangal A. Veeramachaneni V. Tschanz J.W. Ye Y. Somasekhar D. Bloechel B.A. Dermer G.E. Krishnamurthy R.K. Soumyanath K. Mathew S. Narendra S.G. Stan M.R. Thompson S. De V. Borkar S. 《Solid-State Circuits, IEEE Journal of》2002,37(11):1421-1432
A 32-bit integer execution core containing a Han-Carlson arithmetic-logic unit (ALU), an 8-entry /spl times/ 2 ALU instruction scheduler loop and a 32-entry /spl times/ 32-bit register file is described. In a 130 nm six-metal, dual-V/sub T/ CMOS technology, the 2.3 mm/sup 2/ prototype contains 160 K transistors. Measurements demonstrate capability for 5-GHz single-cycle integer execution at 25/spl deg/C. The single-ended, leakage-tolerant dynamic scheme used in the ALU and scheduler enables up to 9-wide ORs with 23% critical path speed improvement and 40% active leakage power reduction when compared to a conventional Kogge-Stone implementation. On-chip body-bias circuits provide additional performance improvement or leakage tolerance. Stack node preconditioning improves ALU performance by 10%. At 5 GHz, ALU power is 95 mW at 0.95 V and the register file consumes 172 mW at 1.37 V. The ALU performance is scalable to 6.5 GHz at 1.1 V and to 10 GHz at 1.7 V, 25/spl deg/C. 相似文献
103.
Chandran A.R. Mathew T. Aanandan C.K. Mohanan P. Vasudevan K. 《Electronics letters》2004,40(20):1245-1246
Electromagnetic scattering behaviour of a superstrate loaded metallo-dielectric structure based on Sierpinski carpet fractal geometry is reported. The results indicate that the frequency at which backscattering is minimum can be tuned by varying the thickness of the superstrate. A reduction in backscattered power of /spl sim/44 dB is obtained simultaneously for both TE and TM polarisations of the incident field. 相似文献
104.
The rates of gas-phase thermolysis reactions of 2-acetylcyclopentanone 1,2-acetylcyclohexanone 2, N-acetylcaprolactam 3,2-acetylbutyrolactone 4,2-acetyl-2-methylbutyrolactone 5, and 3-acetyl-2-oxazolidinone 6 have been measured over a temperature range of 50 K. They undergo unimolecular first-order elimination reactions for which log A = 11.7, 11.7, 11.2, 11.4, 11.5, and 11.1 s?1 and Ea = 193.4, 189.5, 153.2, 201.0, 206.8, and 176.1 kJ mol?1, respectively. The effect of the ring size together with the effect of a heteroatom in the ring on the rate of thermolysis reactions for compound 1–6 is the subject of this work. © 1995 John Wiley & Sons, Inc. 相似文献
105.
An n-CdS/p-CdTe heterostructure is studied. The heterostructure is obtained using the sequential growth of CdS and CdTe layers by electrochemical deposition and closed-space sublimation, respectively. The measured current-voltage characteristics are interpreted in the context of the Sah-Noyce-Shokley generation-recombination model for the depletion layer of a diode structure. The theory quantitatively agrees with the experimental results. 相似文献
106.
Arseniyadis S Subhash PV Valleix A Mathew SP Blackmond DG Wagner A Mioskowski C 《Journal of the American Chemical Society》2005,127(17):6138-6139
We have described a spectacular salt effect in the kinetic resolution of (+/-)-1-phenylethylamine, which leads to an increase in reactivity, high levels of selectivity, and a complete reversal of the stereoselectivity. By tuning the reaction conditions, we were able to increase the selectivity factor of (1S,2S)-1 to s = 115. 相似文献
107.
108.
Knox JE Halls MD Hratchian HP Schlegel HB 《Physical chemistry chemical physics : PCCP》2006,8(12):1371-1377
Tris(8-hydroxyquinoline)aluminum(III), AlQ3, is used in organic light-emitting diodes (OLEDs) as an electron-transport material and emitting layer. The reaction of AlQ3 with trace H2O has been implicated as a major failure pathway for AlQ3-based OLEDs. Hybrid density functional calculations have been carried out to characterize the hydrolysis of AlQ3. The thermochemical and atomistic details for this important reaction are reported for both the neutral and oxidized AlQ3/AlQ3+ systems. In support of experimental conclusions, the neutral hydrolysis reaction pathway is found to be a thermally activated process, having a classical barrier height of 24.2 kcal mol(-1). First-principles infrared and electronic absorption spectra are compared to further characterize AlQ3 and the hydrolysis pathway product, AlQ2OH. The activation energy for the cationic AlQ3 hydrolysis pathway is found to be 8.5 kcal mol(-1) lower than for the neutral reaction, which is significant since it suggests a role for charge imbalance in promoting chemical failure modes in OLED devices. 相似文献
109.
Mathew SP Klussmann M Iwamura H Wells DH Armstrong A Blackmond DG 《Chemical communications (Cambridge, England)》2006,(41):4291-4293
Kinetic evidence supports the role of the reaction product in the catalytic cycle of proline-mediated alpha-aminoxylation and alpha-amination reactions, providing both design principles as well as a model for the evolution of efficiency in catalysis. 相似文献
110.
Modern quantum chemical methods can be used to investigate many properties of novel molecules and materials with predictive power. We have carried out accurate quantum chemical calculations with cluster models to investigate chemical reactions on semiconductor surfaces. The structure–property relationships that emerge from these studies are illustrated with particular emphasis on silicon as well as indium phosphide surface chemistry. Some new strategies that we have developed to provide a proper balance between covalent and dative bonding in compound semiconductors are discussed. Embedded cluster models have been used in some cases to include the effects of the surroundings on the active region. The structural and mechanistic understanding that emerges from our studies is illustrated by selected results on atomic layer deposition of Al2O3 on silicon and hydrogenation of P-rich and In-rich indium phosphide surfaces. 相似文献