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About Bis(dialkylamino)acyloxyboranes By reactions of bis(dialkylamino)bromoborane with potassium, lead, silver or trialkylammonium salts of corresponding carboxylic acids the above listed compounds have been prepared. Some properties of the compounds are described. 相似文献
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A novel temperature-imaging technique based on laser-induced fluorescence of nitric oxide is presented, analyzed and applied. Multi-line rotational thermometry is combined with an efficient spectra-fitting procedure in an imaging configuration. The technique is sensitive over a wide range of temperatures and robustly applicable to different steady combustion and flow systems. Application is shown in premixed and partially premixed ethylene/air Bunsen flames with equivalence ratios between 0.7 and 3.0, and the results are compared to coherent anti-Stokes Raman-scattering temperature measurements. The technique is robust against strong elastic scattering from soot in the rich flames. It yields absolute, quantitative temperature measurements without the necessity of external calibration. PACS 07.20.Dt; 42.62.Fi; 32.50.+d; 33.20.Lg 相似文献
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T.?LeeEmail author W.G.?Bessler C.?Schulz M.?Patel J.B.?Jeffries R.K.?Hanson 《Applied physics. B, Lasers and optics》2004,79(4):427-430
UV planar laser-induced fluorescence (PLIF) images of hot carbon dioxide (CO2) are obtained in a laminar flame (CH4/air) at high pressure (20 bar) with excitation wavelengths at 239.34 nm and 242.14 nm. Excitation wavelengths are chosen to minimize the contribution of nitric oxide and molecular oxygen LIF signals. Spectrally resolved single point measurements are used for correction of the remaining oxygen LIF interference. The continuum LIF signal from electronically excited CO2 is detected in a broad (280–400 nm) emission region. The UV PLIF of hot CO2 has the potential for application to a wide variety of diagnostic needs in high-pressure flames, combustors, and engines. PACS 42.62.Fi; 42.30.Va; 07.25+k; 39.30+w 相似文献
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We use tools of the equilibrium statistical mechanics of disordered systems to study analytically the statistical properties of an ecosystem composed of N species interacting via random mutual interactions, as well as via deterministic self-interactions of order p>/=2. We show that the main effect of increasing the order of the interactions among the species is to make the system less competitive, in the sense that the fraction of extinct species is greatly reduced. In addition, we find that for p>2 there is a threshold value which gives a lower bound to the concentration of the surviving species, preventing then the existence of rare species and, consequently, increasing the robustness of the ecosystem to external perturbations. 相似文献
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B Kleine G L?ffler H Kaufmann P Scheipers H Schickle R Westermeier W G Bessler 《Electrophoresis》1992,13(1-2):73-75
Using polyacrylamide electrode gels during horizontal sodium lauryl sulfate-polyacrylamide electrophoresis of radiolabeled proteins instead of electrode papers reaching into electrode buffer reservoirs, silver staining is improved and we reduce chemical and radioactive liquid waste during electrophoresis. 相似文献
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Tutuianu M Inderwildi OR Bessler WG Warnatz J 《The journal of physical chemistry. B》2006,110(35):17484-17492
Density functional theory (DFT) quantum chemical calculations are used to determine adsorption energies and geometries of NO, NO(2), CO(2), and H(2)O on a barium oxide (100) surface. The study includes two adsorption geometries for NO(2). All species form thermodynamically stable adsorbates, and adsorption strength increases in the order NO(2) < H(2)O < NO = CO(2). The influence of surface coverage on adsorption energy is investigated for all species, and a strong coverage dependence is observed. For CO(2), a chemisorbed, carbonate-type structure is identified; the adsorption from the gas phase is nonactivated. Numerical calculations of the competitive adsorption/desorption equilibria of the four species show that, under typical engine exhaust gas composition, the BaO surface is carbonated to a large extent. The results indicate that carbon dioxide plays an essential role in the surface processes during NO(x)() storage on BaO, where it can block a large part of available surface sites. 相似文献
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T. Lee W. G. Bessler J. Yoo C. Schulz J. B. Jeffries R. K. Hanson 《Applied physics. B, Lasers and optics》2008,93(2-3):677-685
The fluorescence quantum yield for ultraviolet laser-induced fluorescence of CO2 is determined for selected excitation wavelengths in the range 215–250 nm. Wavelength-resolved laser-induced fluorescence (LIF) spectra of CO2, NO, and O2 are measured in the burned gases of a laminar CH4/air flame (φ=0.9 and 1.1) at 20 bar with additional NO seeded into the flow. The fluorescence spectra are fit to determine the relative contribution of the three species to infer an estimate of fluorescence quantum yield for CO2 that ranges from 2–8×10?6 depending on temperature and excitation wavelength with an estimated uncertainty of ±0.5×10?6. The CO2 fluorescence signal increases linearly with gas pressure for flames with constant CO2 mole fraction for the 10 to 60 bar range, indicating that collisional quenching is not an important contributor to the CO2 fluorescence quantum yield. Spectral simulation calculations are used to choose two wavelengths for excitation of CO2, 239.34 and 242.14 nm, which minimize interference from LIF of NO and O2. Quantitative LIF images of CO2 are demonstrated using these two excitation wavelengths and the measured fluorescence quantum yield. 相似文献
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Preparation and Crystal Structures of Silver(I) Mixed Ligand Complexes with Bibenzimidazole and Triphenylphosphane: [Ag(PPh3)2(bbimH2)](COOCH3) · 2 CH2Cl2 and [{Ag(PPh3)2}2(μ-bbim)] · 4 CH2Cl2 The title compounds are obtained from silver acetate, 2,2′-bibenzimidazole and PPh3. They are characterized by their IR, 1H-NMR, 31P-NMR spectra and crystal structure determinations. [Ag(PPh3)2(bbimH2)](COOCH3) · 2 CH2Cl2: Reaction in CH2Cl2. Space group C2/c, Z = 4, 3129 observed unique reflections, R = 0.033. Lattice parameters at 203 K: a = 1450.8; b = 1556.2; c = 2316.4 pm; β = 99.69°. The crystal structure is built up by monomeric molecules with distorted tetrahedral coordination of the silver atom (AgP2N2) and bibenzimidazole as a bidentate ligand. The acetate ion is linked to the NH-groups of the bibenzimidazole by hydrogen bonds. [{Ag(PPh3)2}2(μ-bbim)] · 4 CH2Cl2: Reaction in fused PPh3 at 180 °C. Space group P 1, Z = 1. 9227 observed unique reflections, R = 0.051. Lattice parameters at 203 K: a = 1276.5; b = 1352.1; c = 1408.1 pm; α = 96.97; β = 115.87; γ = 96.84°. The crystal structure is built up by centrosymmetric molecules with distorted tetrahedral coordination of the silver atoms (AgN2P2) and bibenzimidazolate(2–) as tetradentate bridging ligand. 相似文献
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