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41.
A coterie, which is used to realize mutual exclusion in distributed systems, is a family C of subsets such that any pair of subsets in C has at least one element in common, and such that no subset in C contains any other subset in C. Associate with a family of subsets C a positive Boolean function fc such that fc(x) = 1 if the Boolean vector x is equal to or greater than the characteristic vector of some subset in C, and 0 otherwise. It is known that C is a coterie if and only if fc is dual-minor, and is a non-dominated (ND) coterie if and only if fc is self-dual. We study in this paper the decomposition of a positive self-dual function into smaller positive self-dual functions, as it explains how to represent and how to construct the corresponding ND coterie. A key step is how to decompose a positive dual-minor function f into a conjunction of positive self-dual functions f1,f2,…, fk. In addition to the general condition for this decomposition, we clarify the condition for the decomposition into two functions f1, and f2, and introduce the concept of canonical decomposition. Then we present an algorithm that determines a minimal canonical decomposition, and a very simple algorithm that usually gives a decomposition close to minimal. The decomposition of a general self-dual function is also discussed. 相似文献
42.
Saito Toshihide Widayat Wiwin winiati Hagiwara Kazuyoshi Murakami Yukio 《Analytical and bioanalytical chemistry》1984,319(4):433-434
Analytical and Bioanalytical Chemistry - 相似文献
43.
Toshihide Tsukatani Hajime Katano Hirosuke Tatsumi Mika Deguchi Naoki Hirayama 《Analytical sciences》2006,22(2):199-200
The tetraoctylammonium cation forms water-immiscible room temperature ionic liquids with dodecylsulfate and dodecylbenzenesulfonate anions. The ionic liquids are halogen-free and can be considered environmentally friendly solvents. At 25 degrees C, the solubilities of water in tetraoctylammonium dodecylsulfate and tetraoctylammonium dodecylbenzenesulfonate were 2.8 and 4.0%, respectively, and the densities were 0.92 and 0.93 g cm(-3). The ionic liquids formed stable interfaces with water at 25 degrees C. The possible use of tetraoctylammonium dodecylsulfate as chelate extraction solvent was evaluated by using 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione as extractant. Tetraoctylammonium dodecylsulfate showed high extraction performance for divalent transition metal cations. 相似文献
44.
Hatsui T Setoyama H Kosugi N Wassermann B Bradeanu IL Rühl E 《The Journal of chemical physics》2005,123(15):154304
Kr 3d ionization energies of small, variable size krypton clusters are investigated by photoelectron spectroscopy, where the size regime of clusters with an average size N< or =30 is studied. Characteristic shifts in Kr 3d ionization energies to lower binding energies are found compared to the bare atom. These are also different from those of large krypton clusters. Moreover, we find evidence for photoionization of the krypton dimer. Its 3d ionization energy is barely shifted relative to the atomic value. Results from model calculations considering different isomers and cluster sizes as well as defect sites give evidence that the experimental results can be related to photoionization from different surface sites in variable size krypton clusters. This can be related to site-specific photoemission in small Kr clusters. The results are compared to size effects in Kr 3d near-edge features of variable size Kr clusters as well as recent results on Kr 3d photoionization of large Kr clusters. 相似文献
45.
Toyoki Kunitake Toshihide Nakashima Chuji Aso 《Journal of polymer science. Part A, Polymer chemistry》1970,8(10):2853-2859
1,1′-Divinylferrocene was polymerized with BF3OEt2 and AIBN initiators. Polymers were separated into benzene-soluble and benzene-insoluble fractions, the latter probably being crosslinked. The polymers obtained with BF3OEt2 were shown by infrared and NMR spectroscopy to contain both cyclized (70–80%) and uncyclized units, whereas the radical polymer consisted of more than 96% cyclized units. The benzene-soluble fraction of the cationically obtained polymer softened at temperatures below 150°C, but the insoluble fraction decomposed at 240°C. The radical polymers were stable up to 250–280°C (dec). 相似文献
46.
螺环倍半萜(±)-α-花柏烯-3-酮的全合成 总被引:1,自引:0,他引:1
通过萜品油烯 ( Terpinolene)与 2 ,4-二氧代戊酸甲酯的 de Mayo反应得到 [2 +2 ]光加成产物 ,经反aldol重排 ,再环合成具有螺 [5 ,5 ]十一烷结构的花柏烯基本碳架 ,进而对其官能团进行化学修饰 ,完成了螺环倍半萜 (± ) -α-花柏烯 -3 -酮的全合成 . 相似文献
47.
Yarita T Nakajima R Otsuka S Ihara TA Takatsu A Shibukawa M 《Journal of chromatography. A》2002,976(1-2):387-391
A method for the determination of ethanol in alcoholic beverages by high-performance liquid chromatography-flame ionization detection (HPLC-FID) was developed. An FID system could be directly connected to an HPLC system using pure water as a mobile phase. In a durability test using triacontylsilyl (C30)-silica gel stationary phase for 96 h, no significant change in the retention time of four alcohol compounds was observed. So the HPLC separation of alcoholic beverages was carried out on the C30-silica gel stationary phase. On application to the analysis of six kinds of alcoholic beverages, ethanol could be determined accurately by the proposed method. 相似文献
48.
Montenegro J Bonvin P Takeuchi T Matile S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(47):14159-14166
We report the design, synthesis and evaluation of dynamic "octopus" amphiphiles with emphasis on their efficiency as activators in synthetic membrane-based sensing systems. Previously, we found that the in situ treatment of charged hydrazides with hydrophobic aldehydes or ketones gives amphiphilic counterion activators of polyion transporters in lipid bilayers, and that their efficiency increases with the number of their hydrophobic tails. Herein, we expand this series to amphiphiles with one cationic head (guanidinium or ammonium) and four exchangeable hydrophobic tails. These results, with the highest number of tails reported to date, confirm that dynamic octopus amphiphiles provide access to maximal activity and selectivity. Odorants, such as muscone, carvone, or anisaldehyde are used to outline their usefulness in differential sensing systems that operate based on counterion-activated DNA transporters in fluorogenic vesicles. The enhanced ability of octopus amphiphiles to enable the discrimination of enantiomers as well as that of otherwise intractable ortho, meta, and para isomers and short cyclo-/alkyl tails is demonstrated. These findings identify dynamic octopus amphiphiles as being promising for application to differential sensing, "fragrant" cellular uptake, and slow release. 相似文献
49.
Synthesis, characterization, and catalytic reactivity of a highly basic macrotricyclic aminopyridine
Uchida N Taketoshi A Kuwabara J Yamamoto T Inoue Y Watanabe Y Kanbara T 《Organic letters》2010,12(22):5242-5245
The synthesis methods, physicochemical and structural characteristics, and catalytic reactivity of new macrocyclic proton chelators, N,N',N'-tris(p-tolyl)azacalix[3](2,6)(4-pyrrolidinopyridine) and N,N',N'-tris(p-tolyl)azacalix[3](2,6)(4-piperidinopyridine), are studied. The introduction of pyrrolidino and piperidino groups into the pyridine unit enables the enhancement of the synergistic proton affinity of the cavity of the macrotricycle giving a high basicity (pK(BH+) = 28.1 and 27.1 in CD(3)CN), resulting in a catalytic activity for the Michael addition of nitromethane with α,β-unsaturated carbonyl compounds. 相似文献
50.
Yellowish S-containing TiO2 (S-TiO2) powders were prepared by calcination of a mixture of titanium(III) chloride and ammonium thiocyanate solutions. Three kinds of S-TiO2 were prepared by varying the concentration of ammonium thiocyanate (0.5, 1 or 13 M). X-ray photoelectron spectroscopy spectra of the S-TiO2 showed that sulfur atoms existed on the surface of TiO2 powders. But the peaks assigned to S disappeared after Ar+ etching, which means that these atoms were not doped in the bulk of the TiO2 powders. While UV-visible absorption spectra of S-TiO2 showed that the absorption edges of these photocatalysts were seen to shift to a longer wavelength (lower band gap energy) than those of undoped rutile TiO2 prepared and commercial anatase type TiO2 (ST-01). The S-TiO2 (1 M) exhibited higher photocatalytic activity than ST-01 for degradation of methylene blue in aqueous solution under visible light irradiation (lambda > 400 nm). It was also confirmed by IR spectroscopy that acetaldehyde in oxygen under visible light irradiation (lambda > 400 nm) was decomposed to acetic acid by the S-TiO2 and ST-01 at the first decomposition step. 相似文献