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排序方式: 共有1603条查询结果,搜索用时 15 毫秒
21.
高速气流冲击式粉体表面改性装置——HYBRIDIZATION系统及应用 总被引:4,自引:0,他引:4
利用高速气流冲击法进行粉体/粉体系表面改性技术,是迄今为止各种粉体材料开发中最为引人注目的技术之一。HYBRIDIZATION(下称HYB)系统是利用高速气流冲击法对微粉体进行干式/机械化处理,是使材料复合化的最实用的装置,可对各类有机物、无机物、金属等进行广泛组合,通用性很强,适用于许多行业领域。从本文所述的系统构成、型式,有关的典型球形化处理的运转特性,利用复合化高温粉体测定被处理粉体表面温度,利用颜料改变色调等的处理特点及该系统的适用性等(一部分是从已发表的学术论文及专利上摘录的),可以说明HYB系统的概况。 相似文献
22.
Toyama Mitsutoshi; Yamashita Mitsuo; Yoneda Morihide; Zaborowski Andrzej; Nagato Masaki; Ono Hisayo; Hirayama Noriaki; Murooka Yoshikatsu 《Protein engineering, design & selection : PEDS》2002,15(6):477-483
Despite the structural similarities between cholesterol oxidasefrom Streptomyces and that from Brevibacterium, both enzymesexhibit different characteristics, such as catalytic activity,optimum pH and temperature. In attempts to define the molecularbasis of differences in catalytic activity or stability, substitutionsat six amino acid residues were introduced into cholesteroloxidase using site-directed mutagenesis of its gene. The aminoacid substitutions chosen were based on structural comparisonsof cholesterol oxidases from Streptomyces and Brevibacterium.Seven mutant enzymes were constructed with the following aminoacid substitutions: L117P, L119A, L119F, V145Q, Q286R, P357Nand S379T. All the mutant enzymes exhibited activity with theexception of that with the L117P mutation. The resulting V145Qmutant enzyme has low activities for all substrates examinedand the S379T mutant enzyme showed markedly altered substratespecificity compared with the wild-type enzyme. To evaluatethe role of V145 and S379 residues in the reaction, mutantswith two additional substitutions in V145 and four in S379 wereconstructed. The mutant enzymes created by the replacement ofV145 by Asp and Glu had much lower catalytic efficiency forcholesterol and pregnenolone as substrates than the wild-typeenzyme. From previous studies and this study, the V145 residueseems to be important for the stability and substrate bindingof the cholesterol oxidase. In contrast, the catalytic efficiencies(kcat/Km) of the S379T mutant enzyme for cholesterol and pregnenolonewere 1.8- and 6.0-fold higher, respectively, than those of thewild-type enzyme. The enhanced catalytic efficiency of the S379Tmutant enzyme for pregnenolone was due to a slightly high kcatvalue and a low Km value. These findings will provide severalideas for the design of more powerful enzymes that can be appliedto clinical determination of serum cholesterol levels and assterol probes. 相似文献
23.
The O-methylation of phenol with dimethyl carbonate proceeds selectively in the vapor phase over alkali ion exchanged X-zeolites. Thus, a 76% yield of anisole was obtained with a 93% selectivity over NaX at 553 K. The participation of basic sites in the O-methylation is suggested. 相似文献
24.
Katsutoshi Nagaoka Kulathuiyer Seshan Kazuhiro Takanabe Ken-ichi Aika 《Catalysis Letters》2005,99(1-2):97-100
CH4/CO2 reforming over Pt/ZrO2, Pt/CeO2 and Pt/ZrO2 with CeO2 was investigated at 2 MPa. Pt/ZrO2, which shows stable activity under 0.1 MPa, and Pt/CeO2 showed gradual deactivation with time at the high pressure. The deactivation was suppressed drastically on Pt/ZrO2 with CeO2 prepared by different impregnation order (co-impregnation of Pt and CeO2 on ZrO2, and consecutive impregnation of Pt and CeO2 on ZrO2). The amount of coke deposition was found insignificant and similar among all the catalysts (including Pt/ZrO2 and Pt/CeO2). Catalytic activity after the reaction for 24 h was in agreement with Pt particle size after the reaction for same period, indicating that the difference of the catalytic stability is mainly dependent on the extent of Pt aggregation through catalyst preparation, H2 reduction, and the CH4/CO2 reforming. Pt aggregation and the amount of coke deposition were least pronounced on (Pt–Ce)/ZrO2 prepared by impregnation of CeO2 on Pt/ZrO2 and the catalyst showed highest stability. 相似文献
25.
Tsunehiro Aki Kazutaka Hachida Megumi Yoshinaga Yuko Katai Takashi Yamasaki Seiji Kawamoto Toshihide Kakizono Takashi Maoka Seiko Shigeta Osamu Suzuki Kazuhisa Ono 《Journal of the American Oil Chemists' Society》2003,80(8):789-794
Thraustochytrids, marine protists whose dominant genera are Thraustochytrium and Schizochytrium, belong to the kingdom Chromista and are known as an industrial source of DHA. We describe here that thraustochytrid strain
KH105, isolated as a DHA producer, also accumulates significant levels of β-carotene and xanthophylls including canthaxanthin
and astaxanthin. A4-d cultivation using a medium composed of 10% glucose and less than 0.3% of nitrogen sources in a half-concentration
of seawater gave an astaxanthin production up to 6.1 mg/L, and canthaxanthin content reached more than 10 mg/L under conditions
where a higher concentration of nitrogen sources (6%) was employed. It might be advantageous in mass production systems for
these carotenoids to be extracted readily by simply suspending the cells with organic solvents such as acetone and chloroform.
Analyses on the morphological and life history features of the KH105 strain revealed that it belongs to the genus Schizochytrium. This particular species of thraustochytrids is thus considered to be a promising source of xanthophylls as well as DHA for
use in the food industry. 相似文献
26.
This paper presents an adaptive control design for a class of nonsmooth nonlinear systems with matched uncertainty, which is linearly parameterized with a known discontinuous function. The design framework is based on the concept of the Filippov solution as the classical Lyapunov theory for smooth systems cannot be applied to establish the stability of the adaptive control system due to the presence of the discontinuity. It is proved that as an adaptive control system, the global Lyapunov stability with the convergence of the state of the controlled system to the origin can be achieved by evaluating the monotonicity of the Lyapunov function in the state space, particularly on the discontinuous surface, while the uniqueness of the solution of the closed‐loop system is not necessarily guaranteed. Some interesting numerical examples are demonstrated with simulation results. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
27.
Masatsune Kato Takaaki Aoki Takashi Noji Yasuhiro Ono Yoji Koike Tomoyuki Hikita Yoshitami Saito 《Journal of Superconductivity》1994,7(1):37-38
We have investigated the relation between the crystal structure and superconductivity in La1.9Bi0.1CuO4+
, in which the phase separation observed in La2CuO4+
is suppressed. A phase diagram in theT– plane is given for La1.9Bi0.1CuO4+
with excess oxygen. For very small values, the crystal structure is orthorhombic, and an orthorhombic-tetragonal phase transition occurs markedly at 0.03 in the measured temperature range between 13 and 293 K. Superconductivity is observed in the range of 0.04<<0.11. This is clear evidence thathigh-T
c
superconductivity also appears in the tetragonal phase. 相似文献
28.
Yoshikazu Iida Masato Hirai Masato Shiga Tetsushi Ono Tatsuki Inuzuka 《Electrical Engineering in Japan》2023,216(1):e23414
We are planning to develop the new Advanced Distribution Automation System (ADAS) equipped with optical communication network and sectionalizer with sensor for more grid reliability and efficiency on maintenance operation. The new system is featured with the function of fault cause or damaged part estimation. The new sectionalizer captures the waveform of electrical line surge originated by fault and the system analyzes the waveform for this function. This paper mainly introduces the system configuration of ADAS and an early stage examination of fault cause estimation technology. 相似文献
29.
Ono Yuya Kurashige Kentarou Hakim Afiqe Anuar Bin Muhammad Nor Sakamoto Yuma 《Artificial Life and Robotics》2023,28(2):287-294
Artificial Life and Robotics - Although the design of the reward function in reinforcement learning is important, it is difficult to design a system that can adapt to a variety of environments and... 相似文献
30.
Xia Cao Wang Dong F. Ono Takahito Itoh Toshihiro Esashi Masayoshi 《Microsystem Technologies》2022,28(11):2443-2453
Microsystem Technologies - In this paper, a system of magnetically coupled oscillators consisting of a Π-shaped horizontal cantilever and a rectangular vertical cantilever with a frequency... 相似文献