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61.
Bultinck P Augustynen S Hilbers HW Moret EE Tollenaere JP 《Journal of computational chemistry》2002,23(7):746-754
The program Generate, aimed at generating 3-D structures for peptides and peptidomimetics, is presented. The algorithm is based on a build-up procedure, using a library of conformations of amino acid residues. This library is built from conformational analysis of amino acids placed in a di- or tripeptide environment to mimic the surroundings of the amino acid in a true peptide, considering different positions of the residue in the peptide chain (peptidyl fragment, NH(+)(3)-terminus or COO(-)-terminus). Cis-trans isomerism in the amide bonds is taken into account by construction of rotamer libraries for different isomers. Water solvation is included through the GB/SA model. New amino acid residues can easily be added to the libraries, making it possible to generate conformations of peptidomimetics. 相似文献
62.
An on-line solvent (eluent) evaporator is used for reconcentrating a fraction from a first LC column before introduction into a second LC separation step, possibly involving another mobile phase. For pentane and pentane containing 10 % of dichloromethane, evaporation rates of 1 ml/min were achieved. On evaporating a volume of 6 ml, 2-ethylnaphthalene was retained to more than 75%. Separation of aliphatic and polyaromatic hydrocarbons in a linseed oil is shown as an application. 相似文献
63.
In this paper we prove the existence of the quadratic covariation [f(X),X], where f is a locally square integrable function and X
t =
t
0
u
s
dW
s is a smooth nondegenerate Brownian martingale. This result is based on some moment estimates for Riemann sums which are established by means of the techniques of the Malliavin calculus. 相似文献
64.
Recently reported neutron diffraction and paramagnetic susceptibility results on alloys of Tmx Y1?x Al2 are discussed with respect to electron spin resonance measurements on dilute alloys of Er, Dy and Tm in YAl2. The crystalline electric field ground states for Er and Dy do not correspond to those one would expect from the neutron measurements nor is the Tm ground state confirmed. 相似文献
65.
Letm be a fixed non-negative integer. In this work we try to answer the following question: What can be said about a (finite) groupG if all of its irreducible (complex) characters vanish on at mostm conjugacy classes? The classical result of Burnside about zeros of characters says thatG is abelian ifm=0, so it is reasonable to expect that the structure ofG will somehow reflect the fact that the irreducible characters vanish on a bounded number of classes. The same question can also be posed under the weaker hypothesis thatsome irreducible character ofG hasm classes of zeros. For nilpotent groups we shall prove that the order is bounded by a function ofm in the first case but only the derived length can be bounded in general under the weaker condition. For solvable groups the situation is not so well understood although we shall prove that the Fitting height can be bounded by a double logarithmic function ofm, improving a recent result by G. Qian. 相似文献
66.
67.
D. Batani C. Botto M. Moret M. Milani G. Lucchini K. Eidmann F. Cotelli C. Lora Lamia Donin G. Poletti T. Ford A. Stead 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(2):167-179
In this paper the results of an experiment on soft X-ray contact microscopy using a laser-plasma source are presented. A resolution
of 50 nm has been achieved imaging pig sperm cells, while other specimens, such as algae and yeast cells, showed internal
details, proving the technique to be a powerful tool for biological investigations. Original biological information has been
obtained and the conditions for optimal image formation have been studied.
Received 5 June 2002 Published online 24 September 2002
RID="a"
ID="a"e-mail: batani@mib.infn.it 相似文献
68.
Léon Witteman Tim Evers Zhan Shu Dr. Martin Lutz Prof. Dr. Robertus J. M. Klein Gebbink Dr. Marc‐Etienne Moret 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):6087-6099
A range of silanes was synthesized by the reaction of HSiCl3 with iminopyrrole derivatives in the presence of NEt3. In certain cases, intramolecular hydrosilylation converts the imine ligand into an amino substituent. This reaction is inhibited by factors such as electron‐donating substitution on Si and steric bulk. The monosubstituted (DippIMP)SiHMeCl (DippIMP=2‐[N‐(2,6‐diisopropylphenyl)iminomethyl]pyrrolide), is stable towards hydrosilylation, but slow hydrosilylation is observed for (DippIMP)SiHCl2. Reaction of two equivalents of DippIMPH with HSiCl3 results in the hydrosilylation product (DippAMP)(DippIMP)SiCl (DippAMP=2‐[N‐(2,6‐diisopropylphenyl)aminomethylene]pyrrolide), but the trisubsitituted (DippIMP)3SiH is stable. Monitoring the hydrosilylation reaction of (DippIMP)SiHCl2 reveals a reactive pathway involving ligand redistribution reactions to form the disubstituted (DippAMP)(DippIMP)SiCl as an intermediate. The reaction is strongly accelerated in the presence of chloride anions. 相似文献
69.
M. Dutoit P. Fazan A. Benjelloun M. Ilegems J.-M. Moret 《Applied Surface Science》1987,30(1-4):333-338
Charge trapping during high-field (Fowler-Nordheim) injection in thin SiO2 films is investigated. Constant and pulsed current injection as well as C-V measurements are used to determine the evolution of trapped charge and interface state densities. The relation between these charges, which can be influenced by temperature and γ radiation, and dielectric breakdown is studied. We establish the dominant role of negative trapped charge. 相似文献
70.
Interlayer metallic interactions are shown to manifest themselves in both stacking correlations and titanium sublattice distortions. A quantitative study is reported through the structure refinement of one of the Ti1.33 S2 superstructures. The interactions seem to involve Coulomb repulsion forces and should be valid in a broad composition range. Lattice distortions are predicted for other structures including the nonstoichiometric 1T structure. 相似文献