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排序方式: 共有266条查询结果,搜索用时 0 毫秒
1.
Melt crystallization of isotactic polypropylene (iPP), containing crystallites of N,N′-dicyclohexyl-2,6-naphthalenedicarboxamide (DCNDCA) as a nucleating agent of the the β-phase iPP crystal, is carried out under a magnetic field (6 T) to obtain the alignment of the iPP crystal induced by magnetic alignment of DCNDCA. In a previous paper, DCNDCA was reported to undergo magnetic alignment in a liquid suspension. The obtained iPP sample exhibits alignment of the β-phase crystal with the c-axis aligned perpendicular to the magnetic field. The comparison of this alignment of iPP with the reported magnetic alignment of DCNDCA indicates that the β-phase crystal grows epitaxially on the DCNDCA crystal. The (330)β plane of the iPP crystal lies on the bc-plane of the DCNDCA crystal in which the direction of the c-axis of the iPP coincides with the direction of the b-axis of the DCNDCA crystal. 相似文献
2.
Masato Sakaguchi Tetsuro Yokono Yuzo Sanada Junkichi Shoma Hisatsugu Kashiwabara 《Fuel》1981,60(2):136-138
The ball-milling of coal with methylmethacrylate monomer was carried out under vacuum at 77 K and at room temperature and in air. The e.s.r. and i.r. spectra of ball-milled material showed that a copolymer of coal and methylmethacrylate was formed on the surfaces of coal created by ball-mining. Oxygen is an inhibitor to this process. 相似文献
3.
High temperature, high pressure e.s.r. measurements of the hydrogenation reaction of Taiheiyo coal in the presence of catalysts were carried out to understand the stabilization of thermally and/or catalytically induced free radicals. A decrease in free radical concentration with increasing temperature was observed for ZnCl2 and SnCl2 · 2H2O catalysts at 10MPa under hydrogen gas. High pressure modified single-cell d.t.a. and p.d.a. equipment augmented the uniquely designed high temperature, high pressure e.s.r. cell. The hydrogenation reaction was monitored under the same experimental conditions as for e.s.r. From the results of the combination of high temperature, high pressure e.s.r. with high pressure d.t.a. and p.d.a., it was established that H2 molecules can react efficiently with free radicals from coal molecules created by the presence of ZnCl2 and SnCl2 · 2H2O catalysts. 相似文献
4.
Yoshihiro Kubota Yusuke Nishizaki Hisanori Ikeya Masami Saeki Tetsunari Hida Sachiko Kawazu Michitaka Yoshida Hidekazu Fujii Yoshihiro Sugi 《Microporous and mesoporous materials》2004,70(1-3):135-149
Two types of organic–inorganic hybrid base catalysts are prepared. Organic-functionalized molecular sieves (OFMSs), particularly “amine-immobilized porous silicates”, are designed based on common idea to immobilize catalytic active sites on silicate surface. Silicate–organic composite materials (SOCMs), such as “ordered porous silicate–quaternary ammonium composite materials”, are the precursors of ordered porous silicates obtained during the synthesis. Both the OFMS and the SOCM are used as the catalysts for Knoevenagel condensation. Among the OFMSs, there is clear tendency that the use of molecular sieve with larger pore volume and/or surface area gives the product in higher yield. Aminopropylsilyl (AP)-functionalized mesoporous silicates such as AP-MCM-41 gives the product in high yield under mild conditions. No loss of activity is observed after repeated use for three times. The SOCMs are also active for the same reaction. The precursors of the mesoporous silicates are more active than those of microporous silicates. This material can be repeatedly used without significant loss of activity. High activity is not due to the leached species. The active sites of the SOCM catalysts are considered to be SiO− moieties located on the pore-mouth. Activity of the SOCM increases when the reaction is carried out without solvent, whereas decrease in activity of the OFMS is observed in the solvent-free system. 相似文献
5.
This paper proposes a synthesis method of gain‐scheduled control systems that switch linear time‐invariant controllers according to hysteresis of the scheduling parameter. Stability and L2‐gain analysis and synthesis methods for switched systems are applied to the switched gain‐scheduled control synthesis using reset of the controller state, where also the reset law is computed via linear matrix inequalities (LMIs). In addition to optimization of an upper bound of L2‐gain, we reduce jumps of control input via an auxiliary optimization. Numerical examples are presented to illustrate the switched gain‐scheduled controller. 相似文献
6.
K. Yoshida Y. Maeno S. Nishizaki S. Ikeda T. Fujita 《Journal of Low Temperature Physics》1996,105(5-6):1593-1598
We have investigated the normal-state conduction of superconducting Sr2RuO4 (Tc 1K), which is isostructural to La2–xSrxCuO4. The resistivity of single crystals shows a crossover at TM130K from 3D metallic conduction at lower temperatures to 2D one at higher temperatures. Concerning the temperature dependence of the out-of-plane resistivity, we present a systematic interpretation based on competition between the life time of the quasiparticles and the time for the quasiparticles to travel between the adjacent RuO2 planes. 相似文献
7.
Theory of Three-Dimensional Discontinuous Deformation Analysis and Its Application to a Slope Toppling at Amatoribashi, Japan 总被引:1,自引:0,他引:1
Jian-Hong Wu Yuzo Ohnishi Gen-Hua Shi Satoshi Nishiyama 《Canadian Metallurgical Quarterly》2005,5(3):179-195
A three-dimensional (3D) rock slope toppling occurred in a discontinuous rock mass. To simulate the failure process and study the mechanism of this rock failure with contact and large displacement in 3D, a new discrete numerical method has been developed called the 3D discontinuous deformation analysis (DDA). This article first introduces the basic principles and then derives the formulas in detail. Finally, the slope failure simulation is applied as an example to investigate the applicability of this new method to rock slope failure research. The simulation results indicate the advantages of using this new method to study the mechanism of a rock slope failure with 3D behavior. 相似文献
8.
Daisuke Akahori Naoki Inui Yusuke Inoue Hideki Yasui Hironao Hozumi Yuzo Suzuki Masato Karayama Kazuki Furuhashi Noriyuki Enomoto Tomoyuki Fujisawa Takafumi Suda 《International journal of molecular sciences》2022,23(16)
Pulmonary fibrosis is a progressive and fatal disorder characterized by dysregulated repair after recurrent injury. Destruction of the lung architecture with excess extracellular matrix deposition induces respiratory failure with hypoxia and progressive dyspnea. The impact of hypoxia on pulmonary endothelial cells during pulmonary fibrogenesis is unclear. Using a magnetic-activated cell sorting system, pulmonary endothelial cells were isolated from a mouse model of pulmonary fibrosis induced by intratracheally administered bleomycin. When endothelial cells were exposed to hypoxic conditions, a hypoxia-inducible factor (HIF)-2α protein was detected in CD31- and α-smooth muscle actin (SMA)-positive cells. Levels of plasminogen activator inhibitor 1, von Willebrand factor, and matrix metalloproteinase 12 were increased in endothelial cells isolated from bleomycin-treated mice exposed to hypoxic conditions. When endothelial cells were cultured under hypoxic conditions, levels of fibrotic mediators, transforming growth factor-β and connective tissue growth factor, were elevated only in endothelial cells from bleomycin-treated and not from saline-treated lungs. The increased expression of α-SMA and mesenchymal markers and collagen production in bleomycin- or hypoxia-stimulated endothelial cells were further elevated in endothelial cells from bleomycin-treated mouse lungs cultured under hypoxic conditions. Exposure to hypoxia damaged endothelial cells and enhanced fibrogenesis-related damage in bleomycin-treated pulmonary endothelial cells. 相似文献
9.
Naoki Yuda Miyuki Tanaka Manabu Suzuki Yuzo Asano Hiroshi Ochi Keiji Iwatsuki 《Journal of food science》2012,77(12):H254-H261
Abstract: Polyphenols, retained in black tea wastes following the commercial production of tea beverages, represent an underutilized resource. The purpose of this study was to investigate the potential use of hot‐compressed water (HCW) for the extraction of pancreatic lipase‐inhibiting polyphenols from black tea residues. Black tea residues were treated with HCW at 10 °C intervals, from 100 to 200 °C. The resulting extracts were analyzed using high‐performance liquid chromatography‐mass spectrometry and assayed to determine their inhibitory effect on pancreatic lipase activity in vitro. Four theaflavins (TF), 5 catechins, 2 quercetin glycosides, quinic acid, gallic acid, and caffeine were identified. The total polyphenol content of extracts increased with increasing temperature but lipase inhibitors (TF, theaflavin 3‐O‐gallate, theaflavin 3′‐O‐gallate, theaflavin 3,3′‐O‐gallate, epigallocatechin gallate, and epicatechin gallate) decreased over 150 °C. All extracts inhibited pancreatic lipase but extracts obtained at 100 to 140 °C showed the greatest lipase inhibition (IC50s of 0.9 to 1.3 μg/mL), consistent with the optimal extraction of TFs and catechins except catechin by HCW between 130 and 150 °C. HCW can be used to extract pancreatic lipase‐inhibiting polyphenols from black tea waste. These extracts have potential uses, as dietary supplements and medications, for the prevention and treatment of obesity. Practical Application: Active forms of lipase inhibitors can be recovered from black tea residues. They could be used as dietary supplements or medications. 相似文献
10.
Yoshihiko Hibi Katsuyuki Fujinawa Seiji Nishizaki Kazuo Okamura Masaharu Tasaki 《Soils and Foundations》2010,50(1):143-159
Diffusion, dispersion, and advection are important processes in multi-gas systems in soils. To date, both Fick's model and the Dusty Gas (DG) model have been used to model the movement of gases in these systems. Dispersion is included in the dispersion-advection equation with Fick's Model for the movement of gases in gas-phase of soil, yet the movement of gases in multi-component gas-soil systems is considered to be expressed more accurately by the DG model than by Fick's model. However to date, no study has investigated the necessity of considering dispersion in the Dusty Gas (DG) model. We carried out column experiments for nitrogen-methane, nitrogen-carbon dioxide, and carbon dioxide-methane binary gas systems in sandy soil, and also did simulations on the same systems using both Fick's model and the DG model. A comparison of the results of the column experiments with our simulations confirmed that there was no need to consider the dispersion in the advection-diffusion equations with the DG model when the velocity of gas was 0.05-0.4 cm/s in Toyoura sand. Furthermore, our experiments and simulations with the DG model showed that, rather than dispersion, tortuosity should be taken into account in application of the DG model to the above condition. 相似文献