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41.
In applying Pressure-Sensitive Paint (PSP) to low-speed flow wind tunnel testing, it is important to minimize any measurement
uncertainties. There are various error sources such as camera noise, misalignment of images due to model displacement and
temperature distribution over the model. Among these factors, the effects of temperature distribution change during tests
on pressure measurement accuracies were studied in the present paper. Pressure and temperature distributions over a simplified
car model (1/10 scale Ahmed model) were measured using PSP and Temperature-Sensitive Paint (TSP). Sequential images were acquired
at the same intervals over the entire test period, including for the conditions before and after the tunnel run. As a result,
it was found that the measurement error caused by temperature distribution over the model could be reduced using a single-point
temperature measurement. In addition, by measuring surface temperature distributions on the model using TSP, it was proved
that the most accurate pressure measurement could be made by rationing the wind-off image acquired immediately after shutting
down the tunnel to the wind-on image acquired immediately before shutting down the tunnel. Using the present measurement technique,
complicated pressure fields over the Ahmed model were successfully visualized. 相似文献
42.
43.
A convenient synthesis of chiral 3,3′-disubstituted 1,1′-binaphthyl-2,2′-disulfonic acids (BINSA, 1) was developed. The key was directed ortho-lithiation of BINSA methyl ester 2 with n-BuLi and subsequent reaction with an electrophile. Electrophiles such as Br2, I2, Me3SiOTf, and i-PrOB(Pin) reacted smoothly with 3,3′-dilithiated BINSA methyl ester, and the corresponding 3,3′-dihalo-, 3,3′-bis(trimethylsilyl)-, and 3,3′-diboryl-BINSA derivatives were obtained in yields of 21–78%. This simple synthetic method is highly attractive since the ability to prepare 3,3′-disubstituted BINOLs in advance can be useful. 相似文献
44.
45.
46.
Shunsuke Kotani Shohei AokiMasaharu Sugiura Makoto Nakajima 《Tetrahedron letters》2011,52(22):2834-2836
Trichlorosilyl triflate, in the presence of a chiral Lewis base catalyst, provides an effective method for the enantioselective direct-type aldol reaction of aldehydes and ketones. A chiral Lewis base induces both the production and activation of trichlorosilyl enol ether, yielding an aldol product in good yield and with high diastereo- and enantioselectivities. 相似文献
47.
Kazuki OsakamaMasaharu Sugiura Makoto Nakajima Shunsuke Kotani 《Tetrahedron letters》2012,53(32):4199-4201
An efficient method was developed for the enantioselective reductive aldol reaction of α,β-unsaturated ketones with aldehydes in the presence of a Lewis base catalyst; conjugate reduction using a tertiary amine and trichlorosilyl triflate, followed by an aldol reaction with BINAP dioxide (BINAPO) as an organocatalyst, gave the corresponding product in high yield with high stereoselectivity. 相似文献
48.
Yoshiteru Sakata Hiroshi Imahori Ken-Ichi Sugiura 《Journal of inclusion phenomena and macrocyclic chemistry》2001,41(1-4):31-36
Guidelines for the design of molecules with a long lifetime of the charge-separated state and for the formation of a self-assembled monolayer were studied by preparing various model compounds linking donor and acceptor with chemical bonds. Based on the obtained results we designed and prepared the SAMs of C60-(porphyrin)-(ferrocene)-(CH2)11SH on a gold surface and observed a photocurrent with high efficiency (25% quantum yield). In addition, a well-defined, rigid-sheet-structured oligoporphyrin with 21 porphyrin chromophores was prepared as a model for antenna chlorophylls. 相似文献
49.
Nariaki Sugiura Hidetoshi Murakami Seong Keon Lee Yasutomo Maeda 《Annals of the Institute of Statistical Mathematics》2006,58(1):93-100
This paper answers the long-standing question of whether the two-sided Wilcoxon rank test for equal sample sizes is unbiased
against a location parameter family of distributions by giving a counterexample. It is also shown that the nonrandomized two-sided
Wilcoxon test for equal sample sizes with the least positive significance level is unbiased. 相似文献
50.
On the use of nickel foil strain gages at varying temperatures 总被引:1,自引:0,他引:1
When a strain gage made of nickel foil attached on the surface of a specimen is subjected to repeated loads, the elastic stress
is measured by observing slip-bands in the foil resulting from repeated strain. Calibration studies with rotating-bending
tests at various temperatures between room temperature and 350°C are performed on round steel bars with nickel foil. The relation
between the threshold stress for the first appearance of slip-bands and the number of stress cycles is examined at varying
temperatures, which provides the calibration values of the nickel foil tested at varying temperatures. Assuming that the first
appearance of slip-bands is based on the linear cumulative damage law, the calibration values at varying temperatures are
calculated from those established by the calibration tests at several constant temperatures. It is found that the calculated
calibration values agree well with the results obtained by the calibration tests at varying temperatures and that the calculation
applying the linear cumulative damage law is a useful method to presume the calibration values at varying temperatures without
performing the experiment. 相似文献