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101.
Wheat differs from corn in biodegradation kinetics and fermentation characteristics. Wheat exhibits a relatively high rate (23% h?1) and extent (78% DM) of biodegradation, which can lead to metabolic problems such as acidosis and bloat in ruminants. The objective of this study was to rapidly characterize the molecular chemistry of the internal structure of wheat (cv. AC Barrie) and reveal both its structural chemical make‐up and nutrient component matrix by analyzing the intensity and spatial distribution of molecular functional groups within the intact seed using advanced synchrotron‐powered Fourier transform infrared (FTIR) microspectroscopy. The experiment was performed at the U2B station of the National Synchrotron Light Source at Brookhaven National Laboratory, New York, USA. The wheat tissue was imaged systematically from the pericarp, seed coat, aleurone layer and endosperm under the peaks at ~1732 (carbonyl C=O ester), 1515 (aromatic compound of lignin), 1650 (amide I), 1025 (non‐structural CHO), 1550 (amide II), 1246 (cellulosic material), 1160, 1150, 1080, 930, 860 (all CHO), 3350 (OH and NH stretching), 2928 (CH2 stretching band) and 2885 cm?1 (CH3 stretching band). Hierarchical cluster analysis and principal component analysis were applied to analyze the molecular FTIR spectra obtained from the different inherent structures within the intact wheat tissues. The results showed that, with synchrotron‐powered FTIR microspectroscopy, images of the molecular chemistry of wheat could be generated at an ultra‐spatial resolution. The features of aromatic lignin, structural and non‐structural carbohydrates, as well as nutrient make‐up and interactions in the seeds, could be revealed. Both principal component analysis and hierarchical cluster analysis methods are conclusive in showing that they can discriminate and classify the different inherent structures within the seed tissue. The wheat exhibited distinguishable differences in the structural and nutrient make‐up among the pericarp, seed coat, aleurone layer and endosperm. Such information on the molecular chemistry can be used for grain‐breeding programs for selecting a superior variety of wheat targeted for food and feed purposes and for predicting wheat quality and nutritive value in humans and animals. Thus advanced synchrotron‐powered FTIR technology can provide a greater understanding of the plant–animal interface. 相似文献
102.
Field evaporation of silver and field desorption of silver surface compounds were investigated by analysing positive ions with a mass spectrometer. In particular, the well known adsorption states of oxygen, and further the interactions of H2O, NH3, H2, CO and CH4 were measured in the field ion mass spectrometer under steady state fields of > 0.1 V/Å with a sensitivity of < 0.1 ions s?1 and at temperatures between 80 °K and 425 °K. Although oxygen is usually chemisorbed at Ag surfaces, no AgO+, AgO+2 or other Ag-O compounds could be detected as positive ions, Ag+ and O2+ are the only observed ions at best image fields in oxygen up to fields of field evaporation of Ag+(≈ 2.2 V/Å). Even after the actual adsorption of oxygen with zero-field (6 × 105 Langmuir at 10?3 Torr) at 323 °K and 473 °K and subsequent application of the desorption field at 210°K no silver-oxygen compounds were found in positive ionic form. Small quantities of AgO+ and AgO+2 were only formed — besides Ag(H2O)x+ complexes — if atomic oxygen was supplied by the field induced dissociation of water.Gases which do not adsorb on silver under zero-field conditions (H2, CO, CH4, N2) yield the ions Ag(H2)n, Ag(CO)n+, n=1, 2; AgCH4+, AgN2+. The situation with H2O and NH3 is more complicated: Molecular ions [Ag(H2O)n]+·mH2O, n=1,…, 4, m=1,…, 8 and [Ag(NH3)n]+·mNH3, n=1, 2, m=1,…, 6 are found besides Ag+.From the temperature and field dependence conclusions are drawn about the mechanisms of evaporation and formation of ionic surface complexes. The activation energies of evaporation of Ag+ are found to depend on the square root of the field strength. In general, the generation of surface compounds can be described by field induced reactions rather than usual gas adsorption. 相似文献
103.
The one body dissipation mechanism is employed to couple the relative motion of two heavy ions to the internal degrees of freedom. Trajectories, energy and angular momentum losses are calculated, and compared with experimental data on deep inelastic scattering. 相似文献
104.
105.
106.
Ohne Zusammenfassung 相似文献
107.
On the orbits of collineation groups 总被引:5,自引:0,他引:5
Richard E. Block 《Mathematische Zeitschrift》1967,96(1):33-49
108.
A high-dimensional phase space is reduced in an approximate way to a much smaller dimensional phase space, by singling out a “cluster” of a smaller number of particles (e.g. two or three). We derive the invariant mass distribution of the cluster, and, for fixed invariant mass, its c.m.s. energy distribution. The basis of the method is a two-cluster decomposition of the original phase space into the cluster of interest and the remainder. Simple, explicit formulas are given for all particles massless, and for one particle with mass and the others massless. A recipe is stated for the application of these easily calculable distributions to practical situations where the masses of particles must be taken into account. Numerical examples illustrating the validity of the approximations and applications to high-energy elementary particle collisions are given. 相似文献
109.
M. Block A. Nakkasyan J. Irion F. Navach F. Muller M. Nussbaum 《Nuclear Physics B》1978,140(3):525-532
The e/π ratios at low pT observed in pp collisions at √s = 53 GeV are analysed as a function of R, the ratio of the total number of electrons integrated over electron energies to the total number of pions integrated over pion energies. It is found that R is independent of the decay kinematics and very insensitive to the production dynamics of the parent particles. The total parent cross section times the branching ratio into an electron is calculated, and the result is interpreted as either the total inclusive cross section for production of charmed particles, or as the total cross section for single photons in pp collisions. 相似文献
110.