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1.
Baumgarten N. Jung H. Mehlhorn K. 《Journal of Algorithms in Cognition, Informatics and Logic》1994,17(3)
The dynamic planar point location problem is the task of maintaining a dynamic set S of n nonintersecting (except possibly at endpoints) line segments in the plane under the following operations:
- • Locate (: point): Report the segment immediately above , i.e., the first segment intersected by an upward vertical ray starting at ;
- • Insert (: segment): Add segment to the collection of segments;
- • Delete (: segment): Remove segment from the collection of segments.
2.
C. Baumgarten B. Braun G. Court G. Ciullo P. Ferretti G. Graw W. Haeberli M. Henoch R. Hertenberger N. Koch H. Kolster P. Lenisa A. Nass S.P. Pod'yachev D. Reggiani K. Rith M.C. Simani E. Steffens J. Stewart T. Wise 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):37-49
The use of storage cells has become a standard technique for internal gas targets in conjunction with high energy storage
rings. In case of spin-polarized hydrogen and deuterium gas targets the interaction of the injected atoms with the walls of
the storage cell can lead to depolarization and recombination. Thus the number of wall collisions of the atoms in the target
gas is important for modeling the processes of spin relaxation and recombination. It is shown in this article that the diffusion
process of rarefied gases in long tubes or storage cells can be described with the help of the one-dimensional diffusion equation.
Mathematical methods are presented that allow one to calculate collision age distributions (CAD) and their moments analytically.
These methods provide a better understanding of the different aspects of diffusion than Monte Carlo calculations. Additionally
it is shown that measurements of the atomic density or polarization of a gas sample taken from the center of the tube allow
one to determine the possible range of the corresponding density weighted average values along the tube. The calculations
are applied to the storage cell geometry of the HERMES internal polarized hydrogen and deuterium gas target.
Received 9 July 2001 and Received in final form 18 September 2001 相似文献
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5-Substituted-1,3,4-oxadiazolin-2-ones 2 were synthesized by the oxidation of carbo-t-butoxyhydrazones 1 of aromatic aldehydes with lead tetraacetate or, preferably, iodosobenzene diacetate. In some instances 5-acetoxy-1,3,4-oxadiazoles 3 were obtained along with 2 . The oxidation of carboethoxyhydrazones 4 gave 2-ethoxy-1,3,4-oxadiazoles 5 . 相似文献
6.
S. V. Fokin G. V. Romanenko M. Baumgarten V. I. Ovcharenko 《Journal of Structural Chemistry》2003,44(5):864-869
The organomercury biradical HgL2 (L is deprotonated 4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl) is capable of performing the bridging function for design of multinuclear heterospin systems. This paper describes synthesis and crystal structure of HgL2 and the first multinuclear complexes of Cu(hfac)2 with HgL2. 相似文献
7.
Henry E. Baumgarten Richard G. Parker David L. Von Minden 《Journal of mass spectrometry : JMS》1969,2(12):1221-1237
The mass spectra of six aziridinones (α-lactams) are presented. The six aziridinones exhibit the same general fragmentation pattern, the primary processes being loss of the N-t-butyl group, loss of carbon monoxide and loss of t-butyl isocyanate. Several additional rearrangement or fragmentation processes are observed with specific α-lactams. 相似文献
8.
Summary A method has been developed for the determination of trace levels of 32 pesticides, 19 explosives and 16 polycyclic aromatic
hydrocarbons (PAH) in water in three individual steps. Solid-phase enrichment (SPE) is coupled to high-performance liquid
chromatography (HPLC) with a fully automated system. The organic pollutants are enriched on reusable cartridges packed with
adsorbent materials: pesticides and explosives on a mixed bed of divinylbenzene-ethylvinylbenzene copolymers (LiChrolut EN?) and perfluorinated polyethylene (PolyF?), and polycyclic aromatic hydrocarbons on C18-modified silica (Zorbax? ODS1). Thermally assisted desorption (TAD) has been shown to increase the recovery of analytes significantly. As all enriched
analytes are transferred to the detector, only fifty millilitres of sample is needed for each single on-line analysis, compared
with at least a litre for conventional methods. The separation of the enriched organic analytes is performed on specialized
HPLC columns based on reversed-phase materials. The limits of detection of the system employed were found to be below 100
ng L−1. Use of fluorescence detection for the polycyclic aromatic hydrocarbons resulted in limits of detection in the upper pg L−1 range. Thek values, number of theoretical plates, the recovery rates and the limits of detection of this method for fast screening of
organic pollutants from three fifty-millilitre aqueous samples are described.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996 相似文献
9.
Nikolai Tyutyulkov Fritz Dietz Martin Baumgarten Klaus Müllen 《Macromolecular theory and simulations》1995,4(5):991-1000
The energy spectra of two types of non-helical carbon nanotubes are investigated theoretically. It is shown that either the topological or the correlational contributions determine the width of the band gap. In some cases (for nanotubes with diameter < 1 nm) the electron correlation changes qualitatively the results for the width of the energy gap ΔE: if in the one-electron approximation the band width ΔE = 0, the contribution of the electron correlation becomes dominant and increases the band gap ΔE > 0. At small diameter of the nanotubes (D > 1 nm) the ground state of the tubes corresponds to semiconductors with moderate or narrow energy gap, while at D > 1 nm ΔE decreases monotonously. The energy spectra of the planar ribbon polymers are compared with those of the iso-electronic nanotubes. 相似文献
10.
Lerchen HG Baumgarten J Piel N Kolb-Bachofen V 《Angewandte Chemie (International ed. in English)》1999,38(24):3680-3683
The circumvention of efficient "carbohydrate traps" in the liver is required for targeting glycoconjugates on tumor cells. As shown in the model system of bovine serum albumin (BSA) conjugates, the nature of R(1)-R(3) of the fucose epitope plays an important role in the discrimination of cellular uptake between tumor and liver cells as well as in the cytotoxic activity. 相似文献