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271.
P. J. Fitch P. Kasper A. M. Cooper-Sarkar M. Aderholz N. Armenise T. Azemoon D. Bertrand M. Berggren F. W. Bullock M. Calicchio E. F. Clayton T. Coghen O. Erriquez G. Gerbier J. Guy P. O. Hulth G. Iaselli G. T. Jones M. Lagraa P. Marage R. P. Middleton D. Miller M. M. Mobayyen M. Neveu S. W. O'Neale M. A. Parker R. A. Sansum E. Simopoulou K. Varvell C. Vallée A. Vayaki W. Venus H. Wachsmuth W. Wittek J. Wells E. Zevgolatakos BEBC WA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1986,31(1):51-58
Evidence for a significant higher twist contribution to highz π? production in antineutrino scattering is presented. In events withW>3 GeV andQ 2>1 GeV2 in our data, it accounts for (51 ±8)% of all π? withz above 0.5. It is consistent with thez?Q 2 correlations of Berger's higher twist prediction. The data are inconclusive concerning the predictedy?z correlation andp T dependence. Thez ?Q 2 correlation is not adequately described by the Lund Monte-Carlo. 相似文献
272.
The crystal structure of α-AlB12, reported recently by Higashi, Sakurai, and Atoda is confirmed by an independent investigation of a different crystal. The space group is P41212 (or P43212) and our lattice parameters are a = 10.161(7)Å, c = 14.283(8)Å. The structure was partially solved by Patterson methods, when the full structure was communicated to us by Higashi et al. Utilizing 2393 reflections, our structure refinement yields an R value of 2.6% with very low standard deviations for structural parameters (0.0001 for atomic coordinates of boron atoms). Within the standard deviations there is excellent agreement with all parameters determined by Higashi et al. It is found, nevertheless, that the structural parameters of α-AlB12 do not serve to account for the reported Debye-Scherrer patterns of “BeB6,” “LiB6,” or β-tetragonal boron, all of which have the same cell dimensions and space group as α-AlB12. 相似文献
273.
274.
To develop an efficient green extraction approach for recovery of bioactive compounds from natural plants, we examined the potential of pressurized liquid extraction (PLE) of ginger (Zingiber officinale Roscoe) with bioethanol/water as solvents. The advantages of PLE over other extraction approaches, in addition to reduced time/solvent cost, the extract of PLE showed a distinct constituent profile from that of Soxhlet extraction, with significantly improved recovery of diarylheptanoids, etc. Among the pure solvents tested for PLE, bioethanol yield the highest efficiency for recovering most constituents of gingerol-related compounds; while for a broad concentration spectrum of ethanol aqueous solutions, 70% ethanol gave the best performance in terms of yield of total extract, complete constituent profile and recovery of most gingerol-related components. PLE with 70% bioethanol operated at 1500 psi and 100 °C for 20 min (static extraction time: 5 min) is recommended as optimized extraction conditions, achieving 106.8%, 109.3% and 108.0% yield of [6]-, [8]- and [10]-gingerol relative to the yield of corresponding constituent obtained by 8h Soxhlet extraction (absolute ethanol as extraction solvent). 相似文献
275.
Birk T Pedersen KS Thuesen CA Weyhermüller T Schau-Magnussen M Piligkos S Weihe H Mossin S Evangelisti M Bendix J 《Inorganic chemistry》2012,51(9):5435-5443
The use of kinetically robust chromium(III) fluorido complexes as synthons for mixed 3d-4f clusters is reported. The tendency toward linear {Cr(III)-F-Ln(III)} units dictates the cluster topology. Specifically, we show that reaction of cis-[Cr(III)F(2)(NN)(2)]NO(3) (NN = 1,10-phenanthroline ("phen") or 2,2'-bipyridine ("bpy")) with Ln(NO(3))(3)·xH(2)O produces isostructural series of molecular {Ln(2)Cr(2)} squares (1-9) with linear fluoride bridges. In a parallel fashion, fac-[Cr(III)F(3)L], where L = N,N',N″-trimethyl-1,4,7-triazacyclononane ("Me(3)tacn"), reacts with Nd(NO(3))(3)·6H(2)O to form a fluoride-centered penta-nuclear complex and fac-[Cr(III)F(3)L'], with L' = 1,1,1-tris-((methylamino)methylethane) ("Me(3)tame"), reacts with [Ln(hfac)(3)(H(2)O)(2)] (hfacH = 1,1,1,5,5,5-hexafluoroacetylacetone) to yield an isostructural series of {Ln(3)Cr(2)} (10-14) trigonal bipyramids with no central ligand. The formation of the latter is accompanied by a partial solvolysis of the Cr(III) precursor but without formation of insoluble LnF(3). The magnetic properties of the gadolinium containing clusters allow quantification of fluoride-mediated, antiferromagnetic Gd-Cr exchange interactions of magnitude between 0.14 cm(-1) and 0.71 cm(-1) (? = J(12)?(1)·?(2) formalism) and vanishingly small J(Gd-Gd) of 0.06(0) cm(-1). The large spin and small anisotropy together with weak exchange interactions in the {Gd(3)Cr(2)} (11) cluster give rise to a very large magneto-caloric effect of -ΔS(m) = 28.7 J kg(-1) K(-1) (μ(0)H = 90 to 0 kOe). 相似文献
276.
Separation of patatins and protease inhibitors from potato fruit juice with clay minerals as cation exchangers 总被引:1,自引:0,他引:1
Ralla K Sohling U Suck K Kasper C Ruf F Scheper T 《Journal of separation science》2012,35(13):1596-1602
Potato fruit juice as a by-product of the starch industry contains proteins with interesting functionalities such as protease inhibitors or patatin with its high nutritional value. Due to their functional properties, these proteins are principally of industrial interest. A drawback for the application of these potato proteins is the separation and isolation under maintenance of the biological activity. So far, there are no methods in literature, which are satisfying concerning the costs or the separation performance. In this study, we show a chromatographic approach using natural clay minerals as cation exchangers to separate two protein fractions in potato fruit juice. Additionally, the content of glycoalkaloids naturally occurring in potatoes is significantly reduced in a single step together with the separation of the patatins and the protease inhibitors. 相似文献
277.
Harpham MR Nguyen SC Hou Z Grossman JC Harris CB Mara MW Stickrath AB Kanai Y Kolpak AM Lee D Liu DJ Lomont JP Moth-Poulsen K Vinokurov N Chen LX Vollhardt KP 《Angewandte Chemie (International ed. in English)》2012,51(31):7692-7696
Caught in the light: The fulvalene diruthenium complex shown on the left side of the picture captures sun light, causing initial Ru-Ru bond rupture to furnish a long-lived triplet biradical of syn?configuration. This species requires thermal activation to reach a crossing point (middle) into the singlet manifold on route to its thermal storage isomer on the right through the anti?biradical. 相似文献
278.
Søndergaard M Christensen M Bjerg L Borup KA Sun P Steglich F Iversen BB 《Dalton transactions (Cambridge, England : 2003)》2012,41(4):1278-1283
The thermoelectric properties of a PtSb(2) single crystal containing a stoichiometric gradient were investigated. The gradient was produced by employing a Stockbarger synthesis technique. The gradient was observed through the use of spatial resolved Seebeck coefficient measurements and verified utilizing X-Ray Diffraction and Energy Dispersive X-Ray Spectroscopy. The correlation between Pt/Sb ratio and physical property parameters--Seebeck coefficient, mobility, resistivity and charge carrier concentration--was studied. Elemental analysis by Energy Dispersive X-Ray Spectroscopy, X-Ray Fluorescence and Inductively Coupled Plasma revealed Sb deficiency in the crystal, which explains the observed high charge carrier concentration and metallic properties. The transport properties were measured in the temperature range T = 20-300 K on a polycrystalline sample. Furthermore, ab initio theoretical calculations have been conducted to support the interpretation of the measurements. 相似文献
279.
U. Kasper 《Annalen der Physik》1975,487(2):115-118
In TREDER 's theory of gravitation the active gravitational (SCHWARZSCHILD ) mass is, generally speaking, different from the inertial (rest) mass of a stationary space-bounded field producing system. We consider a certain class of field equations and show that the relative deviation of the inertial (rest) mass from the SCHWARZSCHILD ian mass is very small (≤1/15). 相似文献
280.
This communication reports a theoretical study of the conversion of homocysteine to methionine by methionine synthase. The reaction pathway is based on density functional calculations with large basis sets, including thermodynamic, relativistic, and solvent effects. We find that the suggested SN2 mechanism explains well the experimentally observed reaction rate. The results show that the reaction is highly polar, as reflected in the change of charge density along the reaction coordinate. It is enhanced in the protein by two effects: deprotonation of the bound substrate and desolvation of substrate and cofactor in the rate-determining step. 相似文献