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91.
Turn-on characteristics of GaAs MESFETs are simulated when the gate and the drain voltages are changed abruptly, and quasi-pulsed I-V curves are derived from them. It is discussed how the slow current transients (lag phenomena) and the pulsed I-V curves are affected by the existence of substrate traps and surface states. It is also discussed how the characteristics are influenced by impact ionization of carriers. 相似文献
92.
School of Engineering, Duke University, Durham, North Carolina, 27706. The status of wafer bonding technology especially for
silicon-on-insulator (SOI) materials is reviewed. General advantages of wafer bonding as well as specific problems of wafer
bonding, such as interface bubble formation, and solutions for these problems are discussed. The specific requirements for
SOI materials in terms of SOI layer thickness and the appropriate thinning procedures are dealt with. Interface properties
such as bonding strength and electrical properties are also reviewed. Various device results are mentioned. 相似文献
93.
Thermal properties by DSC, stiffness, melt viscosity, tensile properties, and dynamic mechanical properties were measured for the Na+, K+, Mg2+, Zn2+, Cu2+, Mn2+, and Co2+ salts of poly(ethylene-co-methacrylic acid) (EMAA). The changes in the structure and properties with increasing neutralization are larger in the alkaline and alkaline earth metal salts than in the transition metal salts. The stiffness shows a maximum at 33% neutralization in both the alkaline and alkaline earth metal salts, while no maxima are found up to 60% neutralization in the transition metal salts. The microphase separation of salt group aggregates is observed in both the alkaline and alkaline earth metal salts, but is not seen in the transition metal salts. These differences were attributed to both the stronger ionic interactions and the larger number of carboxyl groups associated with the alkaline and alkaline earth metal salts in the ordered structure of ionic salt groups (ionic crystallites). The mechanical properties measured at low strain, such as stiffness and yield stress, strongly depend on the degree of the crystalline order of the ionic crystallites. The high-strain properties, such as tensile strength and elongation at break, depend on the strength of the ionic interactions and the valence of the cation. 相似文献
94.
Colloidal Processing and Mechanical Properties of Whisker-Reinforced Mullite Matrix Composites 总被引:2,自引:0,他引:2
Yoshihiro Hirata Shinichi Matsushita Yoshimi Ishihara Hiroaki Katsuki 《Journal of the American Ceramic Society》1991,74(10):2438-2442
Aqueous colloidal suspensions in the two systems of CVD-processed ultrafine mullite powder (<0.1 μm), -Si3 N4 whisker and -mullite whisker, were prepared near the isoelectric point of mullite (pH 7.0) to prevent cracking during drying of wet green compacts consolidated by filtration. The freeze-dried porous green compacts were hot-pressed with a carbon die at 1500°C for 1 h at a pressure of 39 MPa in N2 atmosphere. The relative densities of the mullite matrix composites with whiskers of 0 to 10 vol% were in the range of 95.2% to 99.8%. Increasing the fraction of Si3 N4 whisker increased the density, flexural strength, and fracture toughness of the hot-pressed composites. On the other hand, addition of the mullite whisker increased the fracture toughness but decreased the density and strength of the composites. 相似文献
95.
A 4‐Fold‐Symmetry Hexagonal Ruthenium for Magnetic Heterostructures Exhibiting Enhanced Perpendicular Magnetic Anisotropy and Tunnel Magnetoresistance 下载免费PDF全文
96.
Jayawardana BC Hirano T Han KH Ishii H Okada T Shibayama S Fukushima M Sekikawa M Shimada K 《Meat science》2011,89(2):150-153
A commercial adzuki bean extract (AE) was evaluated for antioxidant effectiveness in cured and uncured cooked pork sausages. TBARS values, instrumental color evaluation and sensory panel scores were assessed. For uncured sausages, AE at 0.2% was equally effective as 0.1% butylated hydroxytoluene (BHT) in reducing TBARS values. Similarly, AE at 0.2% significantly (P<0.01) reduced the TBARS in cured sausages. Incorporation of 0.2% AE into sausages produced higher (P<0.05) CIE lab color a* value and lower (P<0.05) L* and b* values. Sensory panels did not detect any difference in color, odor, taste, flavor, and overall acceptance in uncured pork sausages with addition of 0.2% AE. However, there were adverse changes in the color and odor of cured sausages, even though the taste, flavor, and overall acceptance were similar. Therefore, the results suggest that AE is a potential antioxidant. 相似文献
97.
98.
Noriyuki Miyata Hiroyuki IshiiYuji Urabe Taro ItataniTetsuji Yasuda Hisashi YamadaNoboru Fukuhara Masahiko HataMomoko Deura Masakazu SugiyamaMitsuru Takenaka Shinichi Takagi 《Microelectronic Engineering》2011,88(12):3459-3461
Electrical and physical characteristics of the Al2O3/InGaAs interfaces with (1 1 1)A and (1 0 0) orientations were investigated in an attempt to understand the origin of electron mobility enhancement in the (1 1 1)A-channel metal-insulator-semiconductor field-effect-transistor. The (1 1 1)A interface has less As atoms of high oxidation states as probed by X-ray photoelectron spectroscopy. The electrical measurements showed that energy distribution of the interface traps for the (1 1 1)A interface is shifted toward the conduction band as compared to that for the (1 0 0) interface. Laterally-compressed cross-section transmission electron microscopy images showed that the characteristic lengths of the interface roughness are different between the (1 1 1)A and (1 0 0) interfaces. The contributions of the Coulomb and roughness scattering mechanisms are discussed based on the experimental results. 相似文献
99.
Kameyama S Imaki M Hirano Y Ueno S Kawakami S Sakaizawa D Kimura T Nakajima M 《Applied optics》2011,50(14):2055-2068
A feasibility study is carried out on a 1.6 μm continuous-wave modulation laser absorption spectrometer system for measurement of global CO(2)concentration from a satellite. The studies are performed for wavelength selection and both systematic and random error analyses. The systematic error in the differential absorption optical depth (DAOD) is mainly caused by the temperature estimation error, surface pressure estimation error, altitude estimation error, and ON wavelength instability. The systematic errors caused by unwanted backscattering from background aerosols and dust aerosols can be reduced to less than 0.26% by using a modulation frequency of around 200 kHz, when backscatter coefficients of these unwanted backscattering have a simple profile on altitude. The influence of backscattering from cirrus clouds is much larger than that of dust aerosols. The transmission power required to reduce the random error in the DAOD to 0.26% is determined by the signal-to-noise ratio and the carrier-to-noise ratio calculations. For a satellite altitude of 400 km and receiving aperture diameter of 1 m, the required transmission power is approximately 18 W and 70 W when albedo is 0.31 and 0.08, respectively; the total measurement time in this case is 4 s, which corresponds to a horizontal resolution of 28 km. 相似文献
100.
Hanh Hong Chu Yoshiki Kobayashi Dan Van Bui Yasutaka Yun Linh Manh Nguyen Akitoshi Mitani Kensuke Suzuki Mikiya Asako Akira Kanda Hiroshi Iwai 《International journal of molecular sciences》2022,23(24)
Eosinophilic chronic rhinosinusitis (ECRS) is a refractory airway disease accompanied by eosinophilic inflammation, the mechanisms of which are unknown. We recently found that CCL4/MIP-1β—a specific ligand for CCR5 receptors—was implicated in eosinophil recruitment into the inflammatory site and was substantially released from activated eosinophils. Moreover, it was found in nasal polyps from patients with ECRS, primarily in epithelial cells. In the present study, the role of epithelial cell-derived CCL4 in eosinophil activation was investigated. First, CCL4 expression in nasal polyps from patients with ECRS as well as its role of CCL4 in eosinophilic airway inflammation were investigated in an in vivo model. Furthermore, the role of CCL4 in CD69 expression—a marker of activated eosinophils—as well as the signaling pathways involved in CCL4-mediated eosinophil activation were investigated. Notably, CCL4 expression, but not CCL5, CCL11, or CCL26, was found to be significantly increased in nasal polyps from patients with ECRS associated with eosinophil infiltration as well as in BEAS-2B cells co-incubated with eosinophils. In an OVA-induced allergic mouse model, CCL4 increased eosinophil accumulation in the nasal mucosa and the bronchoalveolar lavage (BALF). Moreover, we found that CD69 expression was upregulated in CCL4-stimulated eosinophils; similarly, phosphorylation of several kinases, including platelet-derived growth factor receptor (PDGFR)β, SRC kinase family (Lck, Src, and Yes), and extracellular signal-regulated kinase (ERK), was upregulated. Further, CCR5, PDGFRβ, and/or Src kinase inhibition partially restored CCL4-induced CD69 upregulation. Thus, CCL4, which is derived from airway epithelial cells, plays a role in the accumulation and activation of eosinophils at inflammatory sites. These findings may provide a novel therapeutic target for eosinophilic airway inflammation, such as ECRS. 相似文献