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101.
Hiroshi Suzuki 《Graphs and Combinatorics》1991,7(4):363-375
Let be a distance regular graph with diameterd, and
d
() the set of vertices at distanced from. is said to be thin if the induced subgraph on
d
() is a union of cliques for every vertex. We show that the diameterd is bounded above by a function depending only onk
d, which is the cardinality of
d
(), if is not thin. We also investigate thin distance regular graphs witha
d 0. 相似文献
102.
103.
104.
Host-parasitoid systems with evolving mutation rates are studied. By increasing the growth rate of hosts, the diversity of both species is maintained dynamically. For the lower growth rate, diversity is brought about by mere parasitism. The average mutation rate for parasites is elevated to a high value, while that for hosts is suppressed at a low level. For the higher growth rate, the mutation rates for both hosts and parasites are elevated to form a symbiotic cluster connected by on-going mutation. This symbiotic state is sustained through a chaotic oscillation keeping some coherency among species. For a flat landscape for hosts, dynamical clustering of oscillation is observed. Lyapunov spectra of such oscillations show that high dimensional chaos with small positive exponents underlies in the symbiotic state. This weak high dimensional chaos, termed "homeochaos," is essential to the maintenance of symbiosis in ecosystems. 相似文献
105.
Mori M Oyama Y Suzuki A Takahashi K Yamada M Miyano K Miyata H Takei H Hirata KS Kajita T Kihara K Nakahata M Nakamura K Ohara S Sato N Suzuki Y Totsuka Y Yaginuma Y Koshiba M Suda T Tajima T Fukuda Y Nagashima Y Takita M Kaneyuki K Tanimori T Beier EW Frank ED Frati W Kim SB Mann AK Newcomer FM Van Berg R Zhang W 《Physical review D: Particles and fields》1991,43(9):2843-2846
106.
We study topological conditions that must be satisfied by a compactC ∞ Levi-flat hypersurface in a two-dimensional complex manifold, as well as related questions about the holonomy of Levi-flat hypersurfaces. As a consequence of our work, we show that no two-dimensional complex manifold admits a subdomain Ω with compact nonemptyC ∞ boundary such that Ω ? ?2. 相似文献
107.
108.
S Morimoto Y Hiraki I Togami M Kaji H Niiya I Joja H Yamamoto K Aono S Suzuki M Sunada 《Radioisotopes》1984,33(10):691-698
The mechanism of 201Tl chloride accumulation is unclear in thyroid gland and thyroid tumor. This report examines 108 patients that received thyroid scintigraphy examinations with both 201Tl chloride and sodium 131I. The patients were diagnosed clinically and histologically whenever possible. The ROI were obtained by subtraction imaging with both isotopes and by subtraction positive and negative areas of imaging. Dynamic curves were obtained for 201Tl chloride per square unit of each ROI. The dynamic curve in the radioiodide-accumulated area was examined. The data indicate that the clearance rate of 201Tl chloride (T15) was correlated with the sodium 131I uptake rate at 24 h (r = 0.70). 相似文献
109.
(+)-Disparlure , and the saltmarsh caterpillar moth pheromone enantiomers were synthesized and the stereochemistry of the naturally occurring was shown to be 9, 1O. 相似文献
110.
Takashi Korenaga 《Mikrochimica acta》1979,71(5-6):435-443
Summary An arsine generation-atomic absorption spectroscopic method for the determination of 0.04–4000 p. p. m. of arsenic in antimony compounds is described. The interference from antimony and other elements is eliminated by solvent extraction with benzene. The sample is dissolved in concentrated hydrochloric acid and reduced with titanium(III) chloride. Arsenic(III) is extracted into benzene from 10–12N hydrochloric acid at which concentration no antimony (III) is extracted; arsenic(III) is then back-extracted into water. Arsine is generated with potassium iodide, tin(II) chloride and zinc powder from 2.4N hydrochloric acid solution, and introduced to a nitrogen-hydrogen flame. The method has been tested with various antimony samples.
Zusammenfassung Für die Bestimmung von 0,04–4000 ppm Arsen in Antimonverbindungen wurde ein Verfahren zur Arsinbildung und Atomarabsorption entwickelt. Die Störung durch Antimon und andere Elemente wurde durch Extraktion mit Benzol beseitigt. Die Probe wird in konz. Salzsäure gelöst und mit Titan(III)chlorid reduziert. Arsen(III) wird aus 10–12N Salzsäure mit Benzol extrahiert, ohne daß Antimon(III) mitextrahiert wird; As(III) wird dann in Wasser rückextrahiert. Mit Kaliumjodid, Zinn(II)chlorid und Zinkpulver wird aus 2,4N salzsaurer Lösung Arsin entwickelt und in eine Stickstoff-Wasserstoff-Flamme geleitet. Das Verfahren wurde mit verschiedenen Antimonproben getestet.相似文献