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排序方式: 共有334条查询结果,搜索用时 62 毫秒
31.
A. Ataç S. Petzold J. Nyberg M. Piiparinen C. Rossi Alvarez G. de Angelis D. de Acuna R. A. Bark D. Bazzacco G. Lo Bianco R. Burch A. Buscemi B. Herskind S. Leoni S. Lunardi G. Maron B. Million D. Napoli M. de Poli X. Rico G. Sletten G. Vedovato 《Zeitschrift für Physik A Hadrons and Nuclei》1994,348(4):251-253
A rotational band with 15 transitions has been observed in142Eu in an experiment with the GASP Ge detector array by the110Pd(37Cl,5n) reaction. The average energy spacing between the neighbouring transitions is 60 keV, which is similar to the energy spacings in the superdeformed bands in the mass 140 region. The band has a constant dynamic moment of inertia as suggested by Cranked Shell Model calculations. 相似文献
32.
Lukas Stolzer Antonina Vigovskaya Prof. Christopher Barner‐Kowollik Dr. Ljiljana Fruk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14309-14313
A photochemical approach based on nitrile imine‐mediated tetrazole‐ene cycloaddition is introduced to functionalize gold nanorods with biomolecules. For this purpose, a bifunctional, photoreactive linker containing thioctic acid as the Au anchoring group and a tetrazole moiety for the light‐induced reaction with maleimide‐capped DNA was prepared. The tetrazole‐based reaction on the nanoparticles’ surface results in a fluorescent pyrazoline product allowing for the spectroscopic monitoring of the reaction. This first example of nitrile imine‐mediated tetrazole‐ene cycloaddition (NITEC)‐mediated biofunctionalization of Au nanorods paves the way for the attachment of sensitive biomolecules, such as antibodies and other proteins, under mild conditions and expands the toolbox for the tailoring of nanomaterials. 相似文献
33.
Castro L Dommergue A Larose C Ferrari C Maron L 《The journal of physical chemistry. A》2011,115(22):5602-5608
Methylation reactions of gaseous elementary mercury by halogen containing molecules such as halogenomethane species CH(3)X (with X = Cl, Br, and I) and the dimethylchlorinium ion CH(3)ClCH(3)(+) were investigated at the density functional level. With CH(3)X, the reaction is predicted to be almost athermic and kinetically demanding for a thermal reaction. The reaction can proceed photochemically in the visible range; therefore sunlight may increase the reaction rate. These results compare well with the experimental data. Consecutive methylation of the CH(3)HgX products (with X = Cl, Br, and I) and subsequent formation of CH(3)HgCH(3) were also studied. These reactions are predicted to be kinetically inaccessible and thermodynamically unfavorable. With CH(3)ClCH(3)(+), the reaction is predicted to be athermic but kinetically easy. This is due to the suitability of the methyl transfer reagent. Geometrical and electronic data were systematically analyzed in order to rationalize the results. 相似文献
34.
Meyenberg K Lygina AS van den Bogaart G Jahn R Diederichsen U 《Chemical communications (Cambridge, England)》2011,47(33):9405-9407
SNARE proteins mediate membrane fusion between synaptic vesicles and the plasma membrane. A minimized peptide SNARE model system with reduced complexity was introduced combining the native SNARE transmembrane (TMD) and linker domains with artificial coiled-coil forming peptides. Specific membrane fusion initiated by coiled-coil recognition was shown by lipid and content mixing vesicle assays. 相似文献
35.
36.
Konakchiev A Todorova M Mikhova B Vitkova A Najdenski H 《Natural product communications》2011,6(6):905-906
The essential oil of Achillea distans W. et K. flower heads was analyzed by GC and GC-MS. Altogether 43 components in concentrations more than 0.1% were identified representing 93.5% of the oil composition. The main constituents were 1,8-cineole (16.8%), trans-thujone (9.8%), sabinene (8.2%), borneol (7.5%), beta-pinene (6.5%), and camphor (5.8%). The oil showed moderate activity against Staphylococcus aureus and Candida albicans, and weak activity against Salmonella typhimurium, Proteus vulgaris, and Escherichia coli. 相似文献
37.
Dr. Antonina Antonova Dimitar Simov 《Monatshefte für Chemie / Chemical Monthly》1976,107(6):1487-1491
In the present work the ionization constants of benzothiazolone and its 5- and 6-substituted derivatives in 20 volume % ethanol are determined spectrophotometrically. The influence of the polar effects of the substituents on the ionization of the benzothiazolone is due mainly to the induction effect, confirmed by the correlation between the experimental pK
a values and theTaft 0-constants of the substituents.
Mit 1 Abbildung 相似文献
Mit 1 Abbildung 相似文献
38.
Bernazzani L Duce C Micheli A Mollica V Sperduti A Starita A Tiné MR 《Journal of chemical information and modeling》2006,46(5):2030-2042
In this paper, we report on the potential of a recently developed neural network for structures applied to the prediction of physical chemical properties of compounds. The proposed recursive neural network (RecNN) model is able to directly take as input a structured representation of the molecule and to model a direct and adaptive relationship between the molecular structure and target property. Therefore, it combines in a learning system the flexibility and general advantages of a neural network model with the representational power of a structured domain. As a result, a completely new approach to quantitative structure-activity relationship/quantitative structure-property relationship (QSPR/QSAR) analysis is obtained. An original representation of the molecular structures has been developed accounting for both the occurrence of specific atoms/groups and the topological relationships among them. Gibbs free energy of solvation in water, Delta(solv)G degrees , has been chosen as a benchmark for the model. The different approaches proposed in the literature for the prediction of this property have been reconsidered from a general perspective. The advantages of RecNN as a suitable tool for the automatization of fundamental parts of the QSPR/QSAR analysis have been highlighted. The RecNN model has been applied to the analysis of the Delta(solv)G degrees in water of 138 monofunctional acyclic organic compounds and tested on an external data set of 33 compounds. As a result of the statistical analysis, we obtained, for the predictive accuracy estimated on the test set, correlation coefficient R = 0.9985, standard deviation S = 0.68 kJ mol(-1), and mean absolute error MAE = 0.46 kJ mol(-1). The inherent ability of RecNN to abstract chemical knowledge through the adaptive learning process has been investigated by principal components analysis of the internal representations computed by the network. It has been found that the model recognizes the chemical compounds on the basis of a nontrivial combination of their chemical structure and target property. 相似文献
39.
AbstractHyperspectral imaging is an optical method that provides a large amount of information about the investigated object. Its medical applications are reviewed in this article, including tumor delimitation and identification, assessing tissue perfusion and its pathological conditions (including some complications like diabetic foot ulceration), making accurate surgical decisions, evaluating the health of dental structures, etc. Many of the articles show very promising results that required brief comments by the authors. It is clear that choosing the appropriate hyperspectral imaging system for each medical field, together with the most reliable hyperspectral image processing methods, are the main goals of future studies, before hyperspectral imaging becomes a widely applicable evaluation method in medicine. The authors try to answer some questions on this topic and set up some directions for future research. 相似文献
40.