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排序方式: 共有624条查询结果,搜索用时 531 毫秒
21.
Water-repellent particles were prepared by spraying polytetrafluoroethylene (PTFE) on activated carbon. Gas-liquid volumetric mass transfer coefficient and holdup were determined in gas-liquid cocurrent upflow and downflow packed beds from the measurements of gas desorption and volume, respectively. As the PTFE loading increased, the gas-liquid volumetric mass transfer coefficients in both upflow and downflow modes were enhanced. Gas holdup in the upflow mode increased with the PTFE loading, while the dynamic liquid holdup in the downflow mode decreased. The enhancement of the mass transfer rate from gas to liquid can be explained by the effect of water-repellency on the surface of activated carbon. 相似文献
22.
Kotaro Hama Yuko Fujiwara Masashi Morita Fumiyoshi Yamazaki Yuko Nakashima Shiro Takei Shigeo Takashima Mitsutoshi Setou Nobuyuki Shimozawa Tsuneo Imanaka Kazuaki Yokoyama 《Lipids》2018,53(1):85-102
ABCD1 is a gene responsible for X‐linked adrenoleukodystrophy (X‐ALD), and is critical for the transport of very long‐chain fatty acids (VLCFA) into peroxisomes and subsequent β‐oxidation. VLCFA‐containing lipids accumulate in X‐ALD patients, although the effect of ABCD1‐deficiency on each lipid species in the central nervous system has not been fully characterized. In this study, each phospholipid and lysophospholipid species in Abcd1‐deficient mice brains were profiled by liquid chromatography‐mass spectrometry. Among the phospholipid and lysophospholipid species that are significantly more enriched in Abcd1‐deficient mice brains, VLCFA were present in 75, 15, 5, 4, and 1 species of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, lysophosphatidylcholine, and lysophosphatidylethanolamine, respectively. Most VLCFA were incorporated at the sn‐1 position of phosphatidylcholine and phosphatidylethanolamine. Among the phospholipid species that are significantly less enriched in Abcd1‐deficient mice brains, odd‐numbered saturated or mono‐unsaturated fatty acyl moieties are contained in all phosphatidylcholine species. In addition, a number of phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine species contained highly unsaturated fatty acyl moieties. Intriguingly, 44:1 phosphatidylcholine with VLCFA was mainly distributed in the gray matter, such as the cortex, but not in the white matter in the cerebrum and cerebellum. These results show that ABCD1‐deficiency causes metabolic alternation of long‐chain fatty acids and VLCFA. Moreover, our results imply a molecular mechanism for the incorporation of saturated or monounsaturated VLCFA into the sn‐1 position of phospholipids, and also indicate that the distribution of phospholipids with VLCFA may correlate with the development of X‐ALD. 相似文献
23.
Yoshitoshi Saito Shigeo Hayashi Atsuo Yasumori Kiyoshi Okada 《Journal of Porous Materials》1996,3(4):233-239
This paper describes the effects of calcining conditions of kaolinite on pore structures of the porous materials obtained from the selective leaching of calcined kaolinite using KOH solution. Mesoporous -Al2O3 was the predominant crystalline phase in the samples calcined in the temperature range between 950°C and 1050°C for 24 h. The mean specific surface area of these samples was approximately 250 m2 · g–1 and the mean total pore volume was approximately 0.8 ml · g–1. The pore size distribution curves of these samples showed a sharp peak at around 2–3 nm pore radius. This peak was sharper for the sample calcined at 1000°C for 24 h. On the other hand, the pore sizes of the sample calcined at 1100°C for 24 h increased abruptly to 10–20 nm and this change corresponded to the formation of mullite in the sample. The pore sizes of the samples calcined at 1100°C varied with calcining time. The specific surface area and total pore volume decreased, the longer the calcining time of the samples, and this was correlated with an increase in the amount of mullite in the samples. 相似文献
24.
Masahiro Takahashi Yutaka Kimura Mitsuki Hagiwara Keiki Kishikawa Shigeo Kohmoto 《Synthetic Metals》2011,161(15-16):1557-1562
Improved synthesis and reinvestigation of the magnetic properties of triphenylamine bearing three nitronylnitroxide radicals (1) were carried out. Single crystal X-ray crystallographic analysis of 1 established that its molecular shape had a C3-symmetry. Our newly prepared 1 showed different physical properties from those of reported. SQUID measurements of 1 showed that each of the three spins of 1 behaved independently at room temperature. In contrast, the three spins coupled antiferromagnetically at lower temperature as low as ca. 1.8 K. These spin behaviors can be explained by a regular triangular antiferromagnetic model (J/kB = ?3.3 K) and interpreted as a spin frustration system. 相似文献
25.
Abhijit P. Brahme Kaan Inal Raja K. Mishra Shigeo Saimoto 《Computational Materials Science》2011,50(10):2898-2908
This paper presents a crystal plasticity based finite element analysis employing the new microstructure-based strain hardening model recently presented by Saimoto and Van Houtte (2011) [7] to simulate formability and texture evolution in the commercial aluminum alloy 5754. Simulations are performed to compare the predictive capability of the new hardening model against the common work hardening models using a rate-dependent plasticity formulation. The parameters in the numerical models are calibrated using the X-ray data published by Iadicola et al. (2008) [9] for the aluminum sheet alloy 5754. The predictions of the model for balanced biaxial tension and in-plane plane-strain tests are compared against experimental observations presented in Iadicola et al. (2008) [9]. It is concluded that the new model provides the best predictions of the large strain behavior of Aluminum sheet alloy 5754 subjected to various strain paths. 相似文献
26.
Alexander Bond Steven Benbow James Wilson Alain Millard Shigeo Nakama Myles English Christopher McDermott Benoit Garitte 《岩石力学与岩土工程学报(英文版)》2013,5(1):44-57
At Mont Terri Underground Research Laboratory (URL) Switzerland, a specific experiment has been performed in a tunnel, in order to investigate the hydro-mechano-chemical (HMC) perturbations induced in the argillaceous formation by forced ventilation. This experiment has been selected in the international project DECOVALEX to be used for process model development and validation. The numerical simulation of the geochemical response to the ventilation experiment (VE) is the object of the present paper, focusing on the transport of chloride as a conservative species and sulphate as a reactive species. Utilising the validated hydro-mechanical (HM) results from earlier steps of the DECOVALEX task, reactive and non-reactive transport models, incorporating the current understanding of the geochemistry at the site, were successfully constructed for the whole experimental period. The associated parametric and process uncertainty analyses clearly demonstrate that the basic HM understanding must be sound. However, to demonstrate this degree of robustness, the explicit inclusion of process representations of water desaturation, liquid vaporisation, species exclusion porosity, and redox processes, is required. 相似文献
27.
A method for automatically generating a picture maze from two different images is introduced throughout this paper. The process begins with the extraction of salient contours and edge tangent flow information from the primary image in order to build the overall maze. Thus, mazes with passages flowing in the main edge directions and walls that effectively represent an abstract version of the primary image can be successfully created. Furthermore, our proposed approach makes possible the use of their solution path as a means of illustrating the main features of the secondary image, while attempting to keep its image motif concealed until the maze has been finally solved. The contour features and intensity of the secondary image are also incorporated into our method in order to determine the areas of the maze to be shaded by allowing the solution path to go through them. Moreover, an experiment has been conducted to confirm that solution paths can be successfully hidden from the participants in the mazes generated using our method. 相似文献
28.
Keisuke TanizawaTetsuo Sekiya Shigeo OhshioHiroki Akasaka Hidetoshi Saitoh 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(3):313-317
The development of an intense X-ray source using backscattered X-ray produced using an advanced electrode configuration is described. The electrodes were composed of field emitters deposited on a wire mounted on a perforated plate as the cathode and a copper plate as the anode. Electrons from these emitters collided with the copper plate and X-ray was generated at collision points. The backscattered X-ray in the direction normal to the electron trajectory through a hole in the anode escaped from the vacuum chamber through a beryllium window. Continuous and characteristic X-rays were detected at an applied voltage lower than that of a conventional X-ray source from 3.0 to 9.4 kV, respectively. Moreover, the X-ray dosage measured with a survey meter reached 0.95 mSv/h at 5.0 kV of applied voltage. The transmission images of three types of material used as an X-ray source for the X-ray imaging system indicate three advantages; low power consumption, focal point controllable by adjusting applied voltage, and photographable motion picture of X-ray transmission. 相似文献
29.
Makoto Ishii Kenji Saito Tomokazu Shiga Kiyoshi Igarashi Shigeo Mikoshiba Jooyul Lee Kyoung Ho Kang Heehwan Kim Changbae Park 《Journal of the Society for Information Display》2002,10(1):5-10
A hybrid AWD/AND drive technique has been developed in which an Address‐While‐Display (AWD) scheme is combined with an AND logic characteristic that gas discharges demonstrate. The AWD technique enables AC‐PDPs to be driven at high luminance, while the AND logic reduces the number of scan drivers by an order of magnitude. A detailed analysis of the addressing operation has been made. The hybrid drive utilizes the AND logic in two ways: (1) a combination of two voltage pulses and (2) a combination of a voltage pulse and discharge‐priming particles. It was found that the addressing operation requires the establishment of a discharge between the scan and data electrodes, and also between the scan and display electrodes. 相似文献
30.
An Experimental Study of a Cooperative Positioning System 总被引:3,自引:3,他引:0
Several position identification methods are being used for mobile robots. Dead reckoning is a popular method but due to the error accumulation from wheel slippage, its reliability is low for measurement of long distances especially on uneven surfaces. Another popular method is the landmark method, which estimates current position relative to known landmarks, but the landmark method's limitation is that it cannot be used in an uncharted environment. Thus, this paper proposes a new method called Cooperative Positioning System (CPS) that is able to overcome these shortcomings. The main concept of CPS is to divide the robots into two groups, A and B where group A remains stationary and acts as a landmark while group B moves and then group B stops and acts as a landmark for group A. This process is repeated until the target position is reached. Compared with dead reckoning, CPS has a far lower accumulation of positioning errors, and can also work in three dimensions. Furthermore, CPS employs inherent landmarks and therefore can be used in uncharted environments unlike the landmark method. In this paper, we introduce the basic concept of CPS and its positioning principle. Next, we outline a second prototype CPS machine model (CPS-II) and discuss the method of position estimation using the variance of positioning error and weighted least squares method. Position identification experiments using the CPS-II model give a positioning accuracy of 0.12% for position and 0.32 degree for attitude after the robots traveled a distance of 21.5 m. 相似文献