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81.
82.
Ohne Zusammenfassung 相似文献
83.
Metal-Free Synthesis of 3,3-Disubstituted Oxoindoles by Iodine(III)-Catalyzed Bromocarbocyclizations
DC Fabry M Stodulski S Hoerner T Gulder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):10834-10838
"I" did it: An iodine(III)-mediated bromocarbocyclization was elaborated as an efficient tool for the synthesis of oxoindoles. This method is applicable to a variety of structurally different substrates, also with chemically sensitive groups, and gives access to the heterocycles in a regio- and stereoselective fashion. The indole-2-ones obtained can be converted easily into structurally complex target compounds, such as the alkaloid physostigmine. 相似文献
84.
Rueping M Zoller J Fabry DC Poscharny K Koenigs RM Weirich TE Mayer J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3478-3481
Let there be light: A heterogeneous photocatalytic system based on easily recyclable TiO(2) or ZnO allows cross dehydrogenative coupling reactions of tertiary amines. The newly developed protocols have successfully been applied to various C-C and C-P bond-forming reactions to provide nitro amines as well as amino ketones, nitriles and phosphonates. 相似文献
85.
L. Fabry 《Accreditation and quality assurance》1996,1(3):99-108
Severing principles are reported concerning the certification of and quality assurance in a trace-analysis laboratory that
handles a large number of real samples, about 60 000 analyses/year with 50 validated methods. ISO 9001 emphasizes monitoring
rather than diagnostics. For monitoring purposes the trace-analysis methods must be highly selective and of high precision,
with high throughput and uptime within a justifiable economic framework in the analytical range of interest. All trace-analysis
methods must be cross-checked using independent analytical tools. The analytical laboratory must be fully integrated in the
total quality management of the plant. The analyst must know not only the performance of the trace-analysis tools but also
the materials and processes involved in manufacturing.
Received: 19 October 1995 Accepted: 15 November 1995 相似文献
86.
Summary
We prove the existence of periodic solutions of a second order nonlinear ordinary differential equation whose nonlinearity is at resonance with two successive eigenvalues of the associated linear operator and satisfies some Landesman-Laser type conditions at both of them. 相似文献
87.
Summary A capillary electrophoretic method for the ultra trace determination of anions on silicon wafer surfaces is presented. In
several sets of experiments designed according to the methodology of Taguchi, electrokinetic sample introduction with transient
isotachophoretic preconcentration was simultaneously optimized for peak height, peak area, peak asymmetry, efficiency, peak
resolution, and reproducibility of migration time and peak area. The blank reading of the method showed no cross contamination.
Thus, a detection limit of 10 nmol L−1 and a linear range from 50 to 500 nmol L−1 were obtained and verified by two independent instruments. Furthermore, the method was applied to the determination of anions
on wafers from a regular production line wetting the whole wafer surface with ultrapure water. The capillary electrophoretic
results agree with those obtained by ion chromatography.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996. 相似文献
88.
B. Basnar J. Schn?ller K. F?ttinger G. Friedbacher U. Mayer H. Hoffmann L. Fabry 《Fresenius' Journal of Analytical Chemistry》2000,368(5):434-438
AFM imaging of the adsorption of self-assembled octadecylsiloxane (ODS) monolayers has been utilized for probing surface
properties of silicon wafers. It has been found that both growth rate of the organic films and island size of sub-monolayer
films are influenced by the doping level of the wafers as well as by the surface finishing step during wafer production. Generally,
higher doping levels led to lower adsorption rates and smaller islands. Variation of the sample pretreatment used for surface
finishing of similarly doped wafers led only to significant changes of the island size, but not of the surface coverage. The
results presented open up a valuable perspective for characterizing the surface homogeneity of silicon wafers which is an
important parameter for monitoring-wafers in semiconductor industry.
Received: 26 June 2000 / Revised: 26 July 2000 / Accepted: 1 August 2000 相似文献
89.
D. Elsner B. Bantes O. Bartholomy D. E. Bayadilov R. Beck Y. A. Beloglazov R. Castelijns V. Crede A. Ehmanns K. Essig R. Ewald I. Fabry F. Frommberger K. Fornet-Ponse M. Fuchs C. Funke A. B. Gridnev E. Gutz W. Hillert S. H?ffgen P. Hoffmeister I. Horn I. Jaegle J. Junkersfeld H. Kalinowsky Frank Klein Friedrich Klein E. Klempt M. Konrad M. Kotulla B. Krusche H. L?hner I. V. Lopatin J. Lotz S. Lugert D. Menze T. Mertens J. G. Messchendorp V. Metag C. Morales M. Nanova D. V. Novinski R. Novotny M. Ostrick L. M. Pant H. van Pee M. Pfeiffer A. V. Sarantsev C. Schmidt H. Schmieden B. Schoch S. Shende A. Süle V. V. Sumachev T. Szczepanek U. Thoma D. Trnka D. Walther C. Weinheimer C. Wendel 《The European Physical Journal A - Hadrons and Nuclei》2009,39(3):373-381
At the electron accelerator ELSA a linearly polarised tagged photon beam is produced by coherent bremsstrahlung off a diamond
crystal. Orientation and energy range of the linear polarisation can be deliberately chosen by accurate positioning of the
crystal with a goniometer. The degree of polarisation is determined by the form of the scattered electron spectrum. Good agreement
between experiment and expectations on the basis of the experimental conditions is obtained. Polarisation degrees of % are typically achieved at half of the primary electron energy. The determination of is confirmed by measuring the beam asymmetry, , in photoproduction and by a comparison of the results to independent measurements using laser backscattering. 相似文献
90.
We performed measurements of gettering efficiencies for Cu in silicon wafers with competing gettering sites. Epitaxial wafers
(p/p+) boron-doped with a polysilicon back side allowed us to compare p+ gettering with polysilicon gettering. We further
measured metal distributions in p+/p- epitaxial test wafers, with the p- substrate wafers pretreated for oxygen precipitation
to compare p+ gettering with oxygen precipitate gettering. Our test started with a reproducible spin-on contamination in the
1012 atoms/cm2 range, followed by thermal treatment in order to redistribute the metallic impurity. Wafers were then analyzed by a novel
wet chemical layer-by-layer etching technique in combination with inductively coupled plasma mass spectrometry. This led to
“stratigraphical” concentration profiles of the impurity, with typical detection limits of 5–10×1012 atoms/cm3. Twenty-five percent of the total Cu contamination in the p/p+/poly wafer was found in the p+ layer, whilst 75% was gettered
by the polysilicon. Obviously, polysilicon exhibits a stronger gettering than p+ silicon, but due to the large distance from
the front surface, polysilicon was less effective in reducing impurities from the front side of a wafer compared with p+ gettering.
An epitaxial layer p+ on top of p- substrates with oxygen precipitates gettered 50% of the total Cu; while the other 50% of
the Cu was measured in the p- substrate wafer with oxygen precipitates. Without oxygen precipitates, 100% of the spiked Cu
contamination was detected inside the p+ layer. Gettering by oxygen precipitates thus occurs in the same temperature range
as that where p+ silicon begins to getter Cu.
Received: 3 September 2001 / Accepted: 17 October 2001 / Published online: 27 March 2002 相似文献