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排序方式: 共有441条查询结果,搜索用时 20 毫秒
41.
Steady-state fluorescence anisotropy of diphenylhexatriene and n-(9-anthroyloxy)stearic acids (n=2,12) in rat liver microsomes
showed a marked increase in the early stages of enzymatically or non-enzymatically induced lipid peroxidation. The changes
in fluorescence anisotropy occurred in parallel with the formation of thiobarbituric acid-reactive substances (TBA-RS). Parallel
to these changes, the fluorescence emitted from peroxidized microsomes increased markedly in the early stages of lipid peroxidation.
In contrast to the changes in the fluorescence anisotropy and in the formation of TBA-RS, the fluorescence showed a continuing
increase over the three hr period of lipid peroxidation. Glucose-6-phosphatase was inactivated in the early stages of lipid
peroxidation, whereas NADH-cytochrome b5 reductase underwent a slow deactivation over three hr. The apparently slow deactivation of the peripheral protein may be
explained by the formation of fluorescent substances. 相似文献
42.
43.
Hiroyuki Usui Ousuke Miyamoto Teruaki Nomiyama Yuji Horie Tomoyuki Miyazaki 《Solar Energy Materials & Solar Cells》2005,86(1):123-134
The film electrodes of TiO2, which have two functions of opto-electric conversion and storage of electrochemical energy, were prepared by pulsed laser deposition. To investigate the relationship between the photo-rechargeability and the surface structure, the TiO2 film electrodes with different surface morphology were prepared by changing the inert gas pressure during the deposition. The photo-charged quantity was found to be proportional to the third power of the rms of surface roughness. The results suggest that not only the surface but also the interstices between crystal grains near the surface contribute to the photo-charging with low photo-emf. 相似文献
44.
This work reports the results of laboratory drilling tests conducted in order to measure improvements due to design and cutter modifications on PDC bits intended for use in geothermal well drilling. These tests, using 142.88 mm-dia. PDC full face bits, concentrated on improvements in bit life and cost performance. The tests were performed using granite drilling samples and a laboratory drilling machine at atmospheric conditions. The results from changes in bit and cutter shape are reported in the work. 相似文献
45.
Takuji YokoyamaRyo Ishii Tetsuji ItohKoichi Kitahata Shun-ichi MatsuuraTatsuo Tsunoda Satoshi HamakawaTaka-aki Hanaoka Hironobu NanbuFujio Mizukami 《Materials Letters》2011,65(1):67-69
We present a new enzymatic process for synthesis of l-theanine using glutaminase combined with immobilization technique on a mesoporous silica (MPS). The MPS was firstly attempted to modify with zirconia in order to enhance the durability against the reaction under high pH conditions. The glutaminase on the MPS successfully catalyzed the reaction for the synthesis of l-theanine. The glutaminase/MPS conjugate was subsequently recovered and employed for the reaction again. The conjugate showed the corresponding activity to the first synthesis. This indicates that the conjugate functions as a catalyst for synthesis of l-theanine, having the operational stability sufficient for reuse. 相似文献
46.
Takuji KawamuraMasahiro Misaki Yasuko KoshibaSatoshi Horie Kenji KinashiKenji Ishida Yasukiyo Ueda 《Thin solid films》2011,519(7):2247-2250
The detailed structure of crystalline β-phase poly(9,9-dioctylfluorene) (PFO) films was studied by polarized optical measurements, transmission electron microscopy, and grazing-incidence X-ray diffraction. Crystalline β-phase PFO thin films were fabricated by a friction transfer technique and subsequent vapor treatment. Compared to the α-phase, the lattice parameters of the β-phase crystals shrank along the a-axis (film thickness direction) and elongated along the b-axis (side-chain direction), but the period along the c-axis (main-chain direction) remained nearly equal. These changes in molecular packing were consistent with a planar conformational change from the α-phase to the β-phase of PFO. 相似文献
47.
This paper describes the roles of microstructure and carbides during fatigue crack propagation (FCP) in high V-Cr-Ni cast irons, with varying C and V contents from 1 to 3% and 3.5 to 10%, respectively. FCP tests have been performed using CT specimens in laboratory air at ambient temperature, and FCP behaviour and fracture mechanisms were discussed on the basis of crack closure, crack path profile and fracture surface analysis. In the materials with non-spheroidal vanadium carbide (VC), the effect of C and V contents, i.e. microstructure, was seen when the data were characterized in terms of nominal stress intensity factor range. Also in the materials with spheroidal VC, the effect of microstructure was recognized. After allowing for both crack closure and elastic modulus, the intrinsic FCP resistance still became lower with increasing C and V contents, particularly remarkable in the materials with 3% C and 10% V regardless of VC morphology. In these materials, there existed the mutually competitive mechanisms: one was that accelerated FCP rates such as preferential growth into VCs and VC fracture, and the other was that decelerated FCP rates such as crack deflection, crack closure, secondary cracks, and uncracked-ligament bridging. The former exerted much larger influence on the overall FCP rates than the latter did, thus resulting in the lower intrinsic FCP resistance. 相似文献
48.
49.
The time variations in the electrode potential and mass of an electrodeposited CdTe layer when immersed in a deposition bath under an open-circuit condition were examined using an electrochemical QCM in order to observe the oxidation behavior due to dissolved oxygen. The morphology, composition, and crystallinity of the CdTe layer were also examined by SEM, EPMA, and XRD measurements. In the early stage of immersion, mostly only Cd atoms in the CdTe were found to dissolve from the zinc blende-type CdTe lattice, keeping the flat and smooth surface morphology intact. Then, the remaining Te formed a lattice of elemental Te and covered the CdTe layer. The electrolyte could penetrate the Te layer and access the CdTe layer's surface because the Te layer was porous due to the elution of Cd atoms. Therefore, the preferential dissolution of Cd species continued to occur, and finally, only the porous Te layer remained on the substrate. This dissolution of CdTe supports the validity of the potential-pH diagram of the Cd-Te-NH3-H2O system. 相似文献
50.
Takeyuki Suzuki Yoshitaka Dansui Tetsuji Shirai Chikako Tsubaki 《Journal of Materials Science》1985,20(9):3125-3130
The solid solubility limit, grain orientation, defect structure and electrical conductivity of solidified rhombohedral specimens
in the Bi2O3-BaO system are described. The c-axes (in hexagonal notation) of solidified specimens were almost entirely oriented along the platelet/film thickness. Slow-cooling
(∼ 10−2° Csec−1) of the system gave solid solutions with substitutional type of 2BaO → 2BaBi′ + 20+ V
0
..
for 12 to 32 mol % BaO. High-temperature modification of slowly-cooled sample (16 mol % BaO) showed a conductivity of 8.8×10−1 Ω−1 cm −1 at 600° C along the conduction plane (perpendicular to the c-axis). Rapid quenching (∼ 105° C sec−1) produced solid solutions for 8 to 20 mol % BaO introducing interstitial Ba2+ (10–12 mol % BaO) and Schottky type defects such as VBi‴ and V
Bi
‴
and V
0
..
(16 to 20 mol % BaO), however the high-temperature modification of the rhombohedral structure could not be frozen. 相似文献