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41.
A series of "organic chemical hydrides" such as cyclohexane, methylcyclohexane, cyclohexene, 2-propanol, and cyclohexanol were applied to the direct PEM fuel cell. High performances of the PEM fuel cell were achieved by using cyclohexane (OCV = 920 mV, PD(max) = 15 mW cm(-2)) and 2-propanol (OCV = 790 mV, PD(max) = 78 mW cm(-2)) as fuels without CO(2) emissions. The rates of fuel crossover for cyclohexane, 2-propanol, and methanol were estimated, and the rates of fuel permeation of cyclohexane and 2-propanol were lower than that of methanol. Water electrolysis and electro-reductive hydrogenation of acetone mediated by PEM were carried out and formation of 2-propanol in cathode side was observed. This system is the first example of a "rechargeable" direct fuel cell. 相似文献
42.
Summary The biochemical functions of uridine-diphosphate-amino-sugar conjugates are largely unknown. As a first step to investigate
their biological roles in glycolysis of higher organisms, bovine heart muscle, which metabolizes large quantities of glycogen,
was assayed for uridine-diphosphate-hexosamine. A low molecular mass ultrafiltrate was prepared from the methanolsoluble fraction
of a beef heart homogenate, and the fraction was further purified using anion-exchange and reverse-phase HPLC. Samples were
analyzed by two HPLC methods; anion-exchange in borate buffer and reverse-phase ion-pair chromatography. One newly established
technique employing phenylthiocarbamoyl labelled uridine-diphosphate-hexosamine also was used selectively to separate uridine-diphosphate-hexosamine
from other uridine-diphosphate-sugars. Hydrolysate of purified sample was classified further according to molecular structure.
As a result, phenylthiocarbamoyl labelled HPLC is suitable and easy for the detection of uridine-diphosphate-hexosamine and
its derivatives. 相似文献
43.
44.
In this paper, the authors propose a locally most powerful invariant test for the equality of means in the presence of covariate variables. Also the null and nonnull distributions associated with the above test are developed. This problem arises in covariate discriminant analysis and has been treated by various authors, notably Cochran and Bliss 1948, Ann. Math. Statist.19, 151–176 and Rao 1949, Sankhyã9 343–366; 1966. The test derived here locally dominates in power the tests proposed so far. It is also shown that the Cochran-Bliss test is uniformly most powerful in the class of conditional invariant tests. 相似文献
45.
Borate ions are adsorbed on Sephadex G-25 gel from alkaline media and desorbed reversibly into acidic media; the adsorption is ascribed to complex formation between borate and glucose units in the gel matrix. The coexistence of large amounts of salts, e.g. sodium chloride, ammonium chloride, sodium sulfate, and sodium perchlorate, has little effect on the adsorption. The effect of cations which form complexes with borate can be eliminated by the addition of EDTA. Boron present, in natural waters and rocks at lowlevels can be selectively concentrated by means of a gel column and determined spectrophotometrically by the azomethine-H method. 相似文献
46.
47.
Niidome T Nakashima K Takahashi H Niidome Y 《Chemical communications (Cambridge, England)》2004,(17):1978-1979
Cationic gold nanoparticles, prepared by reducing HAuCl(4) with NaBH(4) in the presence of 2-aminoethanethiol, formed a complex with plasmid DNA, and could be transfected into cultivated cells. 相似文献
48.
Daisuke Tanaka Satoru Yoneda Yoko Yamashiro Akihiro Sakatoku Takuro Kayashima Kasumi Yamakawa Shogo Nakamura 《Applied biochemistry and biotechnology》2012,168(2):327-338
A psychrotrophic Pseudomonas sp. TK-3 was isolated from dirty and cool stream water in Toyama, Japan from which we cloned and characterized the bacterial lipase LipTK-3. The sequenced DNA fragment contains an open reading frame of 1,428?bp that encoded a protein of 476 amino acids with an estimated molecular mass of 50,132?Da. The lipase showed high sequence similarity to those of subfamily ??.3 lipase and had a conserved GXSXG motif around the catalytic Ser residue. Its optimal temperature was 20?C25?°C, lower than in most other subfamily ??.3 lipases. The lipase exhibited about 30?% of maximal activity at 5?°C. The optimal pH value was 8.0. The activity was strongly inhibited by EDTA and was highly dependent on Ca2+. Tricaprylin and p-nitrophenyl caprylate were the most favorable substrates among the triglycerides and p-nitrophenyl esters, respectively. LipTK-3 also showed high activity towards natural substrates including edible vegetable oils and animal fats. Furthermore, LipTK-3 was very active and stable in the presence of several detergents, metal ions, and organic solvents. This cold-adapted lipase may prove useful for future applications. 相似文献
49.
Takuro Abe 《Inventiones Mathematicae》2016,204(1):317-346
50.
Only few categories of free arrangements are known in which Terao’s conjecture holds. One such category consists of 3-arrangements with unbalanced Ziegler restrictions. In this paper, we generalize this result to arbitrary dimensional arrangements in terms of flags by introducing unbalanced multiarrangements. For that purpose, we generalize several freeness criterions for simple arrangements, including Yoshinaga’s freeness criterion, to unbalanced multiarrangements. 相似文献