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排序方式: 共有1291条查询结果,搜索用时 15 毫秒
991.
Bohao Cheng Dr. Hiromu Kashida Dr. Naohiko Shimada Prof. Dr. Atsushi Maruyama Prof. Dr. Hiroyuki Asanuma 《Chembiochem : a European journal of chemical biology》2017,18(16):1568-1572
Photodriven DNA strand displacement by using a 2′,6′‐dimethylazobenzene‐tethered strand and poly(l ‐lysine)‐graft‐dextran (PLL‐g‐Dex) as a chaperone is reported. Rapid strand displacement was reversibly induced by UV and visible‐light irradiation without any toehold portion. To further improve the method, the concentration of PLL‐g‐Dex and the number of equivalents of the photoresponsive strand were optimised. Optimally, 64 % strand displacement was reversibly induced by alternating UV and visible‐light irradiation. 相似文献
992.
In photometric ellipsometry the optical signal is transformed into an electrical signal by a photodetector, and it passes an electronic system to reduce the noise and to amplify the signal. But inherently it will induce a phase shift and an amplitude attenuation of the output signal. Such a specific characteristic of an electronic system depends on the angular frequency of the signal and gives systematic errors to the results of the measurement of rotating-analyzer ellipsometry. We propose a modified method of measurement that enables us to calibrate the electronic system in the ellipsometric measurement configuration. 相似文献
993.
A Uchimura T Shimizu M Nakajima H Ueno K Motoki H Fukushima T Natori Y Koezuka 《Canadian Metallurgical Quarterly》1997,5(7):1447-1452
We examined the effects of 2"- or 3"-monoglycosylated alpha-galactosylceramides (alpha-GalCers) and 2",3"-diglycosylated alpha-GalCers on allogeneic MLR and the proliferation of murine spleen cells. It was found that their ceramide portions greatly affect their immunostimulatory activities, and that the 3"-hydroxyl group plays a more important role in the immunostimulatory effects of alpha-GalCer derivatives than the 2"-hydroxyl group. 相似文献
994.
M Yoshikawa H Shimada T Morikawa S Yoshizumi N Matsumura T Murakami H Matsuda K Hori J Yamahara 《Canadian Metallurgical Quarterly》1997,45(8):1300-1305
The methanolic extract of a food garnish "Tonburi", the fruit of Japanese kochia scoparia (L.) Schrad. (Chenopodiaceae), was found to inhibit the increase in serum glucose-loaded rats. Through bioassay-guided separation, momordin Ic and its 2'-O-beta-D-glucopyranoside were isolated as the active principles from this medicinal foodstuff together with three new saponins named scoparianosides A, B, and C. The structures of scoparianosides A, B, and C were elucidated on the basis of chemical and physicochemical evidence as 3 beta, 22 alpha-dihydroxyolean-12en-28-oic acid (22 alpha-hydroxyoleanolic acid), 3-O-beta-D-xylopyranosyl (1 --> 3)-beta-D-glucopyranosiduronic acid, 3 beta-hydroxyolean -18-en-28-oic acid (morolic acid), 3-O-beta-D-xylopyranosyl(1 --> 3)-beta-D -glucopyranosiduronic acid, and 3 beta-hydroxyolean-13(18)-en-28-oic acid, 3-O-beta-D-xylopyranoxyl(1 --> 3) -beta-D-glucopyranosiduronic acid. Momordin Ic and its 2'-O-beta-D-glucopyranoside, both of which are the principal saponin constituents of this medicinal foodstuffs, were found to potently inhibit glucose and ethanol absorption in rats. 相似文献
995.
Implicit Large Eddy Simulation (ILES) with high-resolution and high-order computational modelling was applied to a turbulent mixing fuel injector flow. In the ILES calculation, the governing equations for three dimensional, non-reactive, multi-species compressible flows were solved using a finite volume Godunov-type method. Up to ninth-order spatial accurate reconstruction methods were examined with a second order explicit Runge–Kutta time integration. Mean and root mean square velocity and mixture fraction profiles showed good agreement with experimental data, which demonstrated that ILES using high-order methods successfully captured complex turbulent flow structure without using an explicit subgrid scale model. The effects of grid resolution and the influence of order of spatial accuracy on the resolution of the kinetic energy spectrum were investigated. An k−5/3 decay of energy could be seen in a certain range and the cut-off wavenumbers increased with grid resolution or order of spatial accuracy. The effective cut-off wavenumbers are shown to be larger than the maximum wavenumbers appearing on the given grid for all test cases, implying that the numerical dissipation represents sufficiently the energy transport between resolved and unresolved eddies. The fifth-order limiter with a 0.6 million grid points was found to be optimal in terms of the resolution of kinetic energy and reasonable computational time. 相似文献
996.
Fujii Y Shimada K Yokota M Hashimoto S Sugita Y Ito H 《The Review of scientific instruments》2008,79(5):056105
A prototype instrument for measuring astronaut body mass under microgravity conditions has been developed and its performance was evaluated by parabolic flight tests. The instrument, which is the space scale, is applied as follows. Connect the subject astronaut to the space scale with a rubber cord. Use a force transducer to measure the force acting on the subject and an optical interferometer to measure the velocity of the subject. The subject's mass is calculated as the impulse divided by the velocity change, i.e., M=integral Fdt/delta v. Parabolic flight by using a jet aircraft produces a zero-gravity condition lasting approximately 20 s. The performance of the prototype space scale was evaluated during such a flight by measuring the mass of a sample object. 相似文献
997.
S. Shimada 《Journal of Materials Science》1996,31(3):673-677
The oxidation of TiC powders was non-isothermally carried out by heating up to 900 °C at a rate of 5°C min–1 and at an oxygen pressure of 2–60 kPa, using a simultaneous thermogravimetric analysis-differential thermal analysis-mass spectroscopy (TGA-DTA-MS) apparatus. It was found that oxidation was divided into four stages, I to IV. Stage I, covering the oxidation fraction, , 0–20%, was probably due to formation of oxycarbide (TiCxO1–x, 0 < x<0.5) with slight heat and CO2 evolution. Oxidation in stages II and III at 20–60% was affected by oxygen pressure; the higher pressure giving rise to very sharp exothermic and CO2 evolution peaks in stage II, which are correlated with the formation of anatase. Oxidation in stage III proceeded gradually with increasing rutile phase. The sample amount also exerted a similar effect on oxidation as the oxygen pressure. 相似文献
998.
A solid state lithium concentration cell LixV2O5/LISICON/Li0.25V2O5 (0.25 x 0.55) was investigated. The open circuit voltage increased monotonously from about 0 mV atx=0.25 to about 270 mV atx=0.55. Cells with variousx-values in the single phase showed similar polarization curves, and their cathode polarizations were slightly larger than the anode polarizations. The cathode potential vs a platinum wire as the third electrode was nearly constant under nitrogen flow, but the anode potential decreased with increase of the lithium content of the sample. During the experiment, Lisicon was satisfactorily stable in contact with LixV2O5. 相似文献
999.
Katsuhiro Ono Hidetoshi Shimada Toshihide Nishimura Shinzo Yamashita Hiroshi Okamoto Yuji Minoura 《应用聚合物科学杂志》1977,21(12):3223-3235
The relationship between the molecular weight of liquid hydroxyl-terminated polybutadiene (HTPB) and the physical properties of the elastomers were investigated. HTPB having various molecular weights were cured with 4,4′-diphenylmethane diisocyanate (MDI) by the one-shot method and the physical properties of these elastomers obtained were measured. The tensile strenght, modulus, tear resistance, and the hardness decreased with increase in the molecular weight of HTPB, and this phenomenon was remarkable in the low molecular weight HTPB (below about 3000). On the other hand, the ultimate elongation increased linearly with increase in the molecular weight of HTPB. The effects of incorporating a short-chain diol, N,N-bis(2-hydroxypropyl)aniline, on the physical properties on the elastomers are also discussed. 相似文献
1000.
Toshihiro?NagaoEmail author Tadashi?Fukami Yoshiharu?Horita Sadao?Komemushi Akio?Sugihara Yuji?Shimada 《Journal of the American Oil Chemists' Society》2003,80(10):975-981
An industrially available preparation of astaxanthin (Ax) from Haematococcus pluvialis contained 41.6 wt% acylglycerols and 24.9 wt% FFA in addition to 14.6 wt% Ax, which was a mixture of free and FA ester forms
(free Ax/Ax monoesters/Ax diesters=4.9∶80.3∶14.8, by mol). Enrichment of Ax by a two-step process was attempted. The first
step was hydrolysis of acylglycerols with Candida rugosa lipase: A mixture of 1.0 kg H. pluvialis cell extracts, 1.0 L water, and 50 U/g-reaction mixture of the lipase was agitated at 30°C for 42 h. The degree of hydrolysis
of acylglycerols reached 94.4%, but Ax esters were not hydrolyzed. Removal of FFA from the resulting oil layer by molecular
distillation enriched the content of Ax esters to 40.8 wt5 (named Ax40). The second step was enzymatic conversion of Ax esters
to free Ax, which successfully proceeded in the presence of ethanol (EtOH). When a mixture of 50.0 g Ax40, 8.2 g EtOH (5 molar
equiv. against FA), 58.2 mL water, and 1500 U/g-mixture of Pseudomonas aeruginosa lipase was stirred at 30°C for 68 h, the free Ax content increased to 89.3 mol%. Free Ax was efficiently recovered by precipitation
with n-hexane. The purity of Ax was thereby raised to 70.2 wt% with a 63.9% overall recovery of the initial content in the cell
extracts. 相似文献