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51.
52.
Zusammenfassung Bei Verbrennungsprozessen emittierte Feinststäube können in der Atmosphäre unterschiedlichste Umwandlungen erfahren. Dabei ist nicht auszuschließen, daß nur schwer filtrierbare, quasi gasförmige Aerosole entstehen, ein Umstand, dem bei Immissionsmessungen bisher wenig Beachtung geschenkt wurde. Daten darüber sind kaum verfügbar. Es wurde daher ein umfangreiches Immissionsmeßprogramm mit neuartiger Probenahmetechnik, die auch die nicht durch Feinstfilter abscheidbaren Species in der Luft erfaßt, begonnen. Wichtiges Ergebnis ist, daß toxische Schwermetalle tatsächlich nicht nur in einer durch Feinstfilter aus der Luft abscheidbaren Form vorliegen. Die Messungen liefern Hinweise, daß die Schadstoffkonzentrationen in der Luft wegen der nicht quantitativen Filtrierbarkeit höher sind als bisher angenommen.
Herrn Prof. Dr. W. Fresenius zum 70. Geburtstag gewidmet 相似文献
New findings on metallic pollutants in the air
Summary Very fine dusts emitted during incineration processes may undergo different transformations in the atmosphere. It cannot be ruled out that quasi-gaseous aerosols are generated which are difficult to filter, a fact to which has been paid little attention until now in air pollution measurements. Relevant data are hardly available. Therefore, a comprehensive air pollution measurement program was started, relying on a novel sampling technique covering also those species in the air which are not removable by very fine filters. The most essential finding is that toxic heavy metals actually occcur not only in a form removable from the air through superfine filters. The measurements indicate that the pollutent concentrations in the air are higher than previously supposed because of the fact that they cannot be filtered quantitatively.
Herrn Prof. Dr. W. Fresenius zum 70. Geburtstag gewidmet 相似文献
53.
New results in SN methyl transfer reaction in the series of Δ2-imidazoline with and without quaternary salt catalyst are reported. The hydrolysis of monocyclic compounds containing the 2-alkyl thio, uronium group leads to the formation of a salt. Rearrangement reactions observed in the “uncatalysed reaction” may be due to a true catalytic reaction. 相似文献
54.
55.
H. Behr H.M. Keppler G. Steyrer H. Metzger J. Peisl 《Journal of Physics and Chemistry of Solids》1983,44(10):985-989
X-Ray measurements of the integrated Bragg intensities from V, Nb and Ta single crystals as a function of hydrogen (D) concentration and temperature have been carried out. Two different methods were applied: (i) the usual angular dispersive method using MoKα1 characteristic radiation; and (ii) the energy dispersive method using the white spectrum of the Mo tube and an intrinsic Ge detector. From the results the thermal Debye-Waller factor for the three metals and its change with hydrogen concentration are determined. The mean square of the thermal displacements (u2) decreases with hydrogen (D) concentration. For NbHx(Dx) this agrees well with (u2) values as determined from measured phonon density of states spectra. The results are also given in terms of a Debye temperature depending on H(D) concentration. 相似文献
56.
Henri J. M. Dou Parina Hassanaly Jacky Kister Gaston Vernin Jacques Metzger 《Helvetica chimica acta》1978,61(8):3143-3148
S-Alkylation in heterocyclic serie by phase transfer catalysis: 2-alkylthiothiazoles, 2-alkylthio-Δ-4-thiazolines and 2-alkylthiobenzothiazoles Some Δ-4-thiazoline-, thiazolidine-, and benzothiazoline-2-thiones have been S-alkylated by phase transfer catalysis; yields averaged 80 to 90%. With halogenated heterocyclic compounds of poor reactivity, the main reaction consisted in a dequaternization of the catalyst by the thiones acting as nucleophiles. 相似文献
57.
S.M. Flatte J.B. Gay R.J. Hemingway S.O. Holmgren M.J. Losty R. Blokzijl J.C. Kluyver G.G.G. Massaro W.J. Metzger J.J.M. Timmermans R.T. Van de Walle P.R. Lamb P. Grossmann 《Physics letters. [Part B]》1976,64(2):225-229
A πω enhancement at 1245 MeV is observed in the reaction K?p → Σ+π?ω. Its properties agree with those of a B meson produced by natural-parity exchange thus establishing a coupling of the B to a system. 相似文献
58.
Shumate WJ Mattern DL Jaiswal A Dixon DA White TR Burgess J Honciuc A Metzger RM 《The journal of physical chemistry. B》2006,110(23):11146-11159
We report spectroscopic characterization and unimolecular rectification (asymmetric electrical conduction) measurements of three donor-sigma-acceptor (D-sigma-A) compounds N-(10-nonadecyl)-N-(1-pyrenylmethyl)perylene-3,4,9,10-bis(dicarboximide) (1), N-(10-nonadecyl)-N-(4-[1-pyrenyl]butyl)perylene-3,4,9,10-bis(dicarboximide) (2), and N-(10-nonadecyl)-N-(2-ferrocenylethyl)perylene-3,4,9,10-bis(dicarboximide) (3). These molecules were arranged as one-molecule thick Langmuir-Blodgett monolayers between Au electrodes. In such an "Au | D-sigma-A | Au" sandwich, molecule 1 is a unimolecular rectifier, with rather small rectification ratios (between 2 and 3 at +/-1 V) that decrease upon cycling. Molecule 2 does not rectify. Molecule 3 rectifies, with a rectification ratio of between 14 and 28 at +/-1 V; the through-film rectification and currents persist, even with scans of +/-2 V, for up to 40 cycles of measurement. Qualitative arguments, based on a two-level rectification mechanism, are consistent with the current asymmetries observed in the monolayers of 1 and 3. 相似文献
59.
Metzger A Diller DJ Lin TH Henderson I Webb ML 《Combinatorial chemistry & high throughput screening》2006,9(5):351-358
Screening of more than 2 million compounds comprising 41 distinct encoded combinatorial libraries revealed a novel structural class of p38 mitogen-activated protein (MAP) kinase inhibitors. The methodology used for screening large encoded combinatorial libraries combined with the statistical interpretation of screening results is described. A strong preference for a particular triaminotriazine aniline amide was discovered based on biological activity observed in the screening campaign. Additional screening of a focused follow-up combinatorial library yielded data expanding the unique combinatorial SAR and emphasizing an extraordinary preference for this particular building block and structural class. The preference is further highlighted when the p38 inhibitor data set is compared to data obtained for a panel of other kinases. 相似文献
60.
Ana Diaz Cristian Mocuta Julian Stangl Mario Keplinger Timm Weitkamp Franz Pfeiffer Christian David Till H. Metzger Günther Bauer 《Journal of synchrotron radiation》2010,17(3):299-307
A study of the coherence and wavefront properties of a pseudo‐channel‐cut monochromator in comparison with a double‐crystal monochromator is presented. Using a double‐grating interferometer designed for the hard X‐ray regime, the complex coherence factor was measured and the wavefront distortions at the sample position were analyzed. A transverse coherence length was found in the vertical direction that was a factor of two larger for the channel‐cut monochromator owing to its higher mechanical stability. The wavefront distortions after different optical elements in the beam, such as monochromators and mirrors, were also quantified. This work is particularly relevant for coherent diffraction imaging experiments with synchrotron sources. 相似文献