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91.
Vidhyānāth K. Rao 《manuscripta mathematica》1989,65(1):47-61
We study the bar spectral sequence converging toh
*(SO(2n+1)), whereh is an algebra theory overBP. The differentials are determined completely ifh=P(l) andn<2
l
. These results will be used in a future paper on the MoravaK-theories ofSO(2n+1), with no restriction onn. As another application, we determineBP
*(Spin(7)) including much of its algebra structure.AMS Subject Classification: 57T10, 57T30, 55N22 相似文献
92.
93.
94.
Hadronization in simple models of quark systems is discussed with emphasis on the combinatorial aspects. The numberN of quarks and the numberN c of colours are the relevant variables. In onedimension and in the meson and baryon sector the problem is completely soluble. When multiquark hadrons are included an iterative procedure still allows a complete solution. Higher dimensions are difficult to treat but global hadronization, without dimensionality constraints, is again soluble. As a general result the baryon/meson ratio is, for large quark densities, rather large, ?1/3 and may grow without limit asN→∞. 相似文献
95.
Characterization of estuarine sediments by near infrared diffuse reflectance spectroscopy 总被引:2,自引:0,他引:2
Moros J Barciela-Alonso MC Pazos-Capeáns P Bermejo-Barrera P Peña-Vázquez E Garrigues S de la Guardia M 《Analytica chimica acta》2008,624(1):113-127
It has been developed a partial least squares near infrared (PLS-NIR) method for the determination of estuarine sediment physicochemical parameters. The method was based on the chemometric treatment of first order derivative reflectance spectra obtained from samples previously lyophilized and sieved through a lower than 63 μm grid. Spectra were scanned from 833 to 2976 nm, averaging 36 scans per spectrum at a resolution of 8 cm−1, using chromatographic glass vials of 9.5 mm internal diameter as measurement cells. Models were built using reference data of 31 samples selected through the use of a hierarchical cluster analysis of NIR spectra of sediments obtained from the Ria de Arousa estuary and prediction parameters were established from a validation set of 50 samples of the same area. pH, redox potential (Eh), carbon (C), nitrogen (N) and hydrogen (H) content together with Sn, Pb, Cd, As, Sb and total Cr and also acid soluble, reducible and oxidable Cr fractions were employed as characteristic parameters of the studied sediments. Standard error of prediction values for C and N content were of the order of 4 and 1.3 mg g−1 for H. Prediction errors for pH and Eh were 0.15 units and 37 mV, respectively, thus indicating the good prediction capabilities of the method. Regarding trace metal concentrations PLS-NIR provided prediction error levels for unknown samples around 20% for Sn, Pb, As and Sb and root mean square errors of prediction around 40% for concentration levels of 400 ng g−1 Cd and 100 μg g−1 Cr. For the different extractable fractions of Cr the residual prediction deviation varied from 1.3 to 1.7 but relative errors found for samples of the validation set were only useful for screening purposes. 相似文献
96.
The reactivity of a series of sulfonylguanidinoacetamides 2A-E towards amines is reported. Guanidinoacetamides 2A-C, containing the arylsulfonylimino moiety, undergo a facile transamidation to give substituted carboxamides 4A-C, through the imidazolidinone intermediate 3. Acetamide 2D, having a methanesulfonylimino substituent, affords the imidazolidinone 3D and no transamidated carboxamides 4 are detected. In the case of guanidinoacetamide 2E, with a p-nitrobenzenesulfonylimino substituent, a Smiles rearrangement was observed. 相似文献
97.
Welch K Nederberg F Bowden T Hilborn J Strømme M 《Langmuir : the ACS journal of surfaces and colloids》2007,23(20):10209-10215
Broadband dielectric spectroscopy was used to investigate the bulk molecular dynamics of a recently developed biodegradable biomimetic ionomer potentially useful for biomedical applications. Isothermal dielectric spectra were gathered for a phosphoryl choline (PC)-functionalized poly(trimethylene carbonate) (PTMC) ionomer and unfunctionalized PTMC at temperatures ranging from 2 to 60 degrees C over a broad frequency range of 10(-3) to 10(6) Hz. Four relaxations were clearly identified, two of which were shown to stem from the PTMC polymer backbone. A detailed analysis showed that the formation of zwitterionic aggregates was responsible for the material's bulk functionality and that bulk conduction processes may provide useful information for assessing the PC ionomer as a candidate for drug delivery applications. Finally, it was concluded that absorbed water concentrates around the aggregates, resulting in an increased mobility of the PC end-groups. 相似文献
98.
A new Schiff base, [H(4)pydmedpt](2+)·2Cl(-), derived from one of the forms of vitamin B(6) has been synthesized by condensation of pyridoxal hydrochloride with N,N-bis[3-aminopropyl]-methylamine (medpt) and characterized by analytical and spectroscopic methods. The molecular structure is calculated by density functional theory (DFT) procedures, and the donor properties of each individual donor atom are evaluated by calculation of the Fukui function. One pot reaction of pyridoxal and medpt with vanadyl acetylacetonate yields the brown complex [V(IV)O(H(2)pydmedpt)](2+)·2Cl(-)1, which upon recrystallization from water crystallizes as [V(IV)O(pydmedpt)]·5H(2)O 2. The compounds are characterized by analytical and spectroscopic methods, 2 being also characterized by single crystal X-ray diffraction. It displays a slightly distorted octahedral geometry around the vanadium atom involving the coordination of N(amine), two N(imine), and O(phenolato) donors of the ligand. One of the phenolato oxygen donors is positioned trans to the terminal O-oxido atom with relatively short V-O(phenolate) {2.041(3) ?} and long V-O(oxido) {1.625(4) ?} bond distances when compared to other known compounds. The two different pK(a) values (6.0 and 7.9) obtained for 1 are due to protonation of the pyridine ring nitrogen atoms having different basic characters, this being also substantiated by theoretical calculation of the proton affinity of the O- and N- atoms of the molecule. The spin Hamiltonian parameters are obtained from the electron paramagnetic resonance (EPR) spectra, but the A(z) value (ca. 155 × 10(-4) cm(-1)) is lower than expected by applying the additivity rule for the present set of equatorial donor atoms (ca. 162-163 × 10(-4) cm(-1)), this being attributed to the strong trans V-O(phenolate) bond. The UV-vis transitions and EPR spectral parameters are calculated by DFT procedures, and both the calculated electronic transitions and the hyperfine coupling constants agree well with those experimentally observed. The inhibitory effect of 1 on FFA release and % glucose uptake determined with isolated rat adipocyte cells gave IC(50) and EC(50) values lower than for V(IV)OSO(4) and of the same order of magnitude of other reported insulin enhancing vanadium compounds. 相似文献
99.
Jekaterina Rjabova Vitālijs Rjabovs Antonio J. Moreno Vargas Elena Moreno Clavijo Māris Turks 《Central European Journal of Chemistry》2012,10(2):386-394
Recently, monosaccharide-triazole conjugates have proved to possess a large variety of useful biological activities. This
paper describes synthesis of a new series of 3-deoxy-3-C-triazolylmethyl-allose derivatives. These new compounds are obtained from acetonide-protected 3-deoxy-3-azidomethyl allose
and commercial alkynes via Cu(I) catalyzed 1,3-dipolar cycloaddition. The obtained molecular scaffolds differ from those described
earlier by the presence of a methylene linker (-CH2-) between the C(3) of allose and the triazole moiety. It was demonstrated that acetonide-protected monosaccharide, 3-deoxy-3-C-(4-phenyl-1H-1,2,3-triazol-1-yl)methyl-1,2:5,6-di-O-isopropylidene-α-d-allofuranose, inhibited α-L-fucosidase for 26% at 0.1 mM concentration, but a deprotected analog, 3-deoxy-3-C-(4-(4-tert-butylphenyl)-1H-1,2,3-triazol-1-yl)methyl-β-d-allofuranose, showed 15% inhibition of β-glucosidase at 1 mM concentration.
相似文献
100.
Assuming $\diamondsuit$ : Whenever B is a totally imperfect set of real numbers, there is special Aronszajn tree with no continuous order preserving map into B. 相似文献