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排序方式: 共有625条查询结果,搜索用时 635 毫秒
11.
Andrej I. Dementev Nikolaj G. Rambidi Vladimir Y.A. Simkin Igor A. Topol Nikolaj F. Stepanov Boris I. Zhilinskii 《Journal of Molecular Structure》1980
The potential surface for the boron(III) oxide (B2O3) ground state has been calculated in restricted HF approximation with a minimal STO—3G basis set. The equilibrium geometry has C2v symmetry; the corresponding structural parameters are as follows: r(Oi—B1)= 1.241 Å; r(Bi—O)= 1.341 Å ; ∠B1QB2 = 142° and ǒO1B1O = 177°. Calculations were also carried out using the SCF-Xα approach for two configurations of B2O3 with C2v and D∞h symmetry. 相似文献
12.
Ladislav Halás Andrej Oriňák Abubaker Sharif Monika Ádámová Juraj Ladomerský 《Central European Journal of Chemistry》2005,3(3):570-582
Acrylate monomers methylmethacrylate (MMA) and cyclohexylmethacrylate (CHMA) bioaccumulation has been determined in aquatic
organism, algae (Chlorella kessleri). Algae were collected in amount of 0.4 mg and directly injected to the pyrolytical cell. In algae bodies accumulated monomers
were analysed by pyrolysis gas chromatography (Py-GC) and pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS).
Traces of the accumulated monomers in algae body can be determined after 1-, 2-, 3-weeks of incubation. Maximum content of
MMA was determined after 3-week of experiment, contrariwise in the case of CHMA after 2-week exposition. Relationship with
pyrolysis temperature has also been studied. 相似文献
13.
Patrik Kolar Andrej Petri
Miha Tiler Fulvia Felluga 《Journal of heterocyclic chemistry》1991,28(7):1715-1720
From the corresponding heterocyclic amino acids 2 and 9a the heterocyclic systems imidazo[1,5-a]pyridine ( 3 ) and imidazo[1,5-a]quinoline ( 10 ) are easily accessible. From compound 7 the tricyclic system 11 was prepared and from compound 17a a pyridyl-1,2,4-triazinone ( 18 ) could be obtained. 相似文献
14.
Anab initio crystal orbital method is used to calculate the energies of an infinite chain of H atoms and of linear arrangements of H2 molecules with different interatomic distances. The H2 arrangements are not stable in respect to isolated molecules. The cohesive energy of an optimized arrangement of H atoms chain is 0.0354 a.u. 相似文献
15.
Mojca Dobnikar Marijan Kočevar Andrej Petrič Miha Tišler Bojan Verček 《Monatshefte für Chemie / Chemical Monthly》1989,120(3):269-272
Summary Syntheses of 1-methylimidazo[1,2-c]quinazolinium iodide (3) and 1-methylimidazo[2,1-f]pyrido[3,2-d]pyrimidinium iodide (4) are described. These tricyclic compounds react with nucleophiles derived from active methylene compounds to give the corresponding open-chain enamines.
Reaktionen von quaternisierten Imidazo-Chinazolinen und -Pyridopyrimidinen mit Verbindungen mit reaktiven Methylengruppen
Zusammenfassung Synthesen von 1-Methylimidazo[1,2-c]chinazoliniumjodid (3) und 1-Methylimidazo[2,1-f]pyrido[3,2-d]pyrimidiniumjodid (4) werden beschrieben. Diese tricyclischen Verbindungen reagieren mit einigen Carbanionen aus Verbindungen mit reaktiven Methylengruppen, wobei die offenkettigen Enamine entstehen.相似文献
16.
In this paper the 4-state latch bridge model proposed by Rembold and Murphy is expanded; first by incorporation of the analytical expression of Ca2+ dependent MLCK activation from the work of Kato et al. and second, by inclusion of the myosin dephosphorylation based on the Michaelis-Menten kinetics. The analysis of the proposed model and the comparison with the original model results as well as with the experimental data is presented. The model is able to predict the steady-state isometric stress and the myosin phosphorylation in dependence on steady cytosolic [Ca2+] as well as the temporal evolution of the system in dependence on the input Ca2+ signal in the form of biphasic transient, whereby our model results are in several aspects in better agreement with experimental observations. 相似文献
17.
Thermodynamic integration (TI) for computing marginal likelihoods is based on an inverse annealing path from the prior to the posterior distribution. In many cases, the resulting estimator suffers from high variability, which particularly stems from the prior regime. When comparing complex models with differences in a comparatively small number of parameters, intrinsic errors from sampling fluctuations may outweigh the differences in the log marginal likelihood estimates. In the present article, we propose a TI scheme that directly targets the log Bayes factor. The method is based on a modified annealing path between the posterior distributions of the two models compared, which systematically avoids the high variance prior regime. We combine this scheme with the concept of non-equilibrium TI to minimise discretisation errors from numerical integration. Results obtained on Bayesian regression models applied to standard benchmark data, and a complex hierarchical model applied to biopathway inference, demonstrate a significant reduction in estimator variance over state-of-the-art TI methods. 相似文献
18.
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20.
A. A. Ershov A. M. Gribushin A. I. Dem’yanov A. A. Kaminskii 《Physics of Particles and Nuclei》2018,49(1):23-25
The HF RADMON system monitors radiation environment in the region of the forward calorimeter of the CMS setup. Measurements of neutron fluxes at energies of 7, 8, and 13 GeV are carried out; estimates of the radiation shielding efficiency are obtained. Modernization of the system for operating under high luminosity conditions is completed and its capabilities to be used as an additional luminometer are confirmed. 相似文献