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41.
42.
We demonstrate a novel method of equalizing a laser diode (LD) beam into a circular beam. This method uses the twist effect of graded index (GI) fiber optics. An asymmetric LD beam with beam qualities of M2 = 500 in the slow axis and M2 = 4 in the fast axis is converted successfully into a symmetric circular beam with a beam quality of M2 = 175. The circular-output beam with 92% coupling efficiency from the fiber input to the fiber output is obtained with a 5-m-long GI1200 (1200 means a core diameter of 1200 microm) fiber for a 2-W LD array. We extend the experiments to a higher-power source with higher asymmetric beam qualities of M2 = 3000 and M2 = 4. By slightly bending the GI10000 (10000 means a core diameter of 10,000 microm) fiber, we have succeeded in generating a symmetric beam with a improved beam quality of M2 = 2000. The average beam quality is preserved when the asymmetric ratio is not high, and the beam quality degradation ratio is investigated up to asymmetric ratios of 750. 相似文献
43.
Kim YJ Yoshizawa M Takenaka S Murakami S Aoki K 《Journal of Bioscience and Bioengineering》2002,93(6):584-588
The two ammonia-assimilating enzymes glutamate dehydrogenase (GDH; EC 1.4.1.4) and glutamine synthetase (GS; EC 6.3.1.2) were synthesized steadily during the cell growth of Klebsiella pneumoniae F-5-2 that can utilize NH4+ and NO3- simultaneously under aerobic conditions. The enzymes were purified to homogeneity from cell extracts and characterized. The molecular mass of the purified GDH was 300 kDa with six identical 52-kDa subunits. GDH showed its maximal activity (aminating) at pH 8.0 and was stable between pHs 5.5 and 11.5. The enzyme was NADP-specific and strongly inhibited by Ag+. It catalyzed the amination of 2-ketovalerate, 2-ketoadipate, and 2-ketobutyrate, in addition to 2-ketoglutarate. The purified GS has a molecular mass of 470 kDa with eight identical 60-kDa subunits. GS showed its maximal activity at pH 8.0 and was stable between pHs 6.0 and 7.0. The enzyme was strongly inhibited by Fe3+, Hg2+, and Cu2+. 相似文献
44.
Kondoh Y. Takenaka T. Hidaka T. Tejima G. Kaneko Y. Saitoh M. 《Journal of microelectromechanical systems》2005,14(2):214-220
Existing mechanical relays have reliability-related issues including unstable contact resistance and limited cycle life. These problems are caused by mechanical fatigue and wearing of the contact surfaces. In the liquid metal micro switch (LiMMS), we employ a liquid-liquid contact to address these issues. The switching operation is achieved by forming a gap in the liquid metal using gas expansion. Our prototype has a microchannel on a glass substrate to hold a tiny amount of mercury, 0.15 mm in width and 0.1 mm in height, and TaN thin-film heaters on a ceramic substrate to expand the operating gas by heating. The substrates are bonded together and the total size of the device is 5/spl times/5/spl times/1.4 mm. We successfully demonstrated 70-m/spl Omega/ on-resistance, 1 ms-switching speed, the ability to handle up to 1 A of dc current and over 1/spl times/10/sup 8/ cycle operation. LiMMS also has good RF performance, better than 1 dB insertion loss, and better than 20 dB isolation up to 18 GHz. 相似文献
45.
A function of image recognition is indispensable to an intelligent robot which can coexist with a human being. Furthermore,
the intelligent robot needs to understand the environment of their action range by getting information of characters and maps
on advertisements and signboards in order to move autonomously. In this research, a method to search the route from the starting
point to the destination on a guidance map, by extracting the road area on the map and revising degradation portions because
of overlapping with characters or other figures is proposed. And the validity of this method is shown by the experiment using
maps which were collected from advertisements or pamphlets. 相似文献
46.
Adrian David Cheok Xubo Yang Zhou Zhi Ying Mark Billinghurst Hirokazu Kato 《Personal and Ubiquitous Computing》2002,6(5-6):430-442
This paper presents a novel computer entertainment system which recaptures human touch and physical interaction with the
real-world environment as essential elements of the game play, whilst also maintaining the exciting fantasy features of traditional
computer entertainment. Our system called ‘Touch-Space’ is an embodied (ubiquitous, tangible, and social) computing based
Mixed Reality (MR) game space which regains the physical and social aspects of traditional game play. In this novel game space,
the real-world environment is an essential and intrinsic game element, and the human’s physical context influences the game
play. It also provides the full spectrum of game interaction experience ranging from the real physical environment (human
to human and human to physical world interaction), to augmented reality, to the virtual environment. It allows tangible interactions
between players and virtual objects, and collaborations between players in different levels of reality. Thus, the system re-invigorates
computer entertainment systems with social human-to-human and human-to-physical touch interactions.
Correspondence to: Professor A. Cheok, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. Email: adriancheok@nus.edu.sg 相似文献
47.
48.
H Takenaka T Yoneda Masahiro YA Fu A Kobayashi M Ikuno K Tsukaguchi Y Okamoto C Yamamoto N Narita 《Canadian Metallurgical Quarterly》1998,36(8):653-658
In this study we utilized bioelectrical impedance analysis (BIA) to compare the body composition of 36 stable pulmonary emphysema (PE) patients with 19 healthy controls. We compared the PE patients and healthy controls in terms of fat-free mass (FFM) and body fat (BF) as percentages of ideal body weight (FFM/IBW, BF/IBW). FFM/IBW and BF/IBW were significantly lower in the PE patients than in the controls (75.0 +/- 9.8% vs. 85.2 +/- 7.3%, p < 0.001 and 11.8 +/- 6.4% vs. 16.7 +/- 7.7%, p < 0.05, respectively). We divided the PE patients into two subgroups according to FFM, then investigated the relationships between FFM and skeletal muscle strength, and between FFM and respiratory muscle strength. In patients with reduced FFM (FFM < 43.5 kg) grip strength as an index of skeletal muscle strength was significantly lower than in patients without reduced FFM (FFM > or = 43.5 kg) (25.7 +/- 7.8 kg vs. 36.2 +/- 7.2 kg, p < 0.005). As indexes of respiratory muscle strength, maximal expiratory pressure (PEmax) and maximal inspiratory pressure (PImax) were lower in the patients with reduced of FFM, but not to a statistically significant degree (49.6 +/- 20.8 cm H2O vs. 58.7 +/- 23.9 cm H2O and 40.5 +/- 19.2 cm H2O vs. 50.2 +/- 22.1 cm H2O, respectively). In the PE patients, FFM correlated closely with vital capacity (r = 0.528, p < 0.001), forced vital capacity (FVC) (r = 0.531, p < 0.001), FEV1.0 (r = 0.554, p < 0.001), FEV1.0/FVC (r = 0.467, p < 0.005), RV/TLC (r = -0.395, p < 0.05), DLco (r = 0.770, p < 0.001), and DLco/VA (r = 0.622, p < 0.001). However no correlation was observed between BF and any of the measures of lung function. The findings of our study suggest that FFM correlates with skeletal muscle strength, respiratory muscle strength and some measures of lung function in patients with PE, and that assessments of body composition are valuable to their clinical management. 相似文献
49.
A Taketomi R Tamada K Takenaka R Kawano T Maeda K Sugimachi 《Canadian Metallurgical Quarterly》1998,5(4):833-835
Biliary cystadenoma is a rare cause of obstructive jaundice. We report a case of a 78-year-old Japanese man with biliary cystadenoma presenting repetitive abdominal pain and jaundice. Ultrasound sonography revealed a hyperechoic mass in the left lateral lobe of the liver. Histological examination revealed a biliary cystadenoma. Intracystic hemorrhage was assumed to be the cause of obstruction of the bile ducts. 相似文献
50.