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排序方式: 共有281条查询结果,搜索用时 31 毫秒
91.
We developed a new electrochromic device by using compact Prussian blue (PB)/antimony tin oxide (ATO) nano-composites as anodic electrode and viologen anchoring on titanium dioxide (TiO2) nano-particles as cathodic electrode. The anodic electrode was based on a transparent nanostructured ATO nano-particle film and was electro-deposited by Prussian blue to form compact Prussian blue/ATO nano-composites by means of galvanostatic electrodeposition process. Nanocrystalline TiO2 thin films on conducting glass were modified with a mono-layer of viologen with two anchoring groups, which were much strongly adsorbed onto the surface of TiO2 nano-particles. A polymer gel electrolyte sandwiched between the anodic and cathodic layers is used as the ionic transport layer. The 2.5 cm × 2.5 cm electrochromic device shows high contrast (64.8%, at 600 nm) very low transmittance at colored stage (0.1%, at 600 nm), fast switching time (600 and 720 ms for coloration and bleaching, respectively), high coloration efficiency of 912 cm2 C−1 at 600 nm and good stability. The enhanced performance of the electrochromic device can be attributed to the ATO nano-particles as inter-conductive materials. 相似文献
92.
Inhibin secretion in the mare: localization of inhibin alpha, betaA, and betaB subunits in the ovary
N Nagamine Y Nambo S Nagata K Nagaoka N Tsunoda H Taniyama Y Tanaka A Tohei G Watanabe K Taya 《Canadian Metallurgical Quarterly》1998,59(6):1392-1398
To determine the source of circulating inhibin and estradiol-17beta during the estrous cycle in mares, the cellular localization of the inhibin alpha, betaA, and betaB subunits and aromatase in the ovary was determined by immunohistochemistry. Concentrations of immunoreactive (ir-) inhibin, estradiol-17beta, progesterone, LH, and FSH in peripheral blood were also measured during the estrous cycle in mares. Immunohistochemically, inhibin alpha subunits were localized in the granulosa cells of small and large follicles and in the theca interna cells of large follicles, whereas inhibin betaA and betaB subunits were localized in the granulosa cells and in the theca interna cells of large follicles. On the other hand, aromatase was restricted to only the granulosa cells of large follicles. Plasma ir-inhibin concentrations began to increase 9 days before ovulation; they remained high until 2 days before ovulation, after which they decreased when the LH surge was initiated. Thereafter, a further sharp rise in circulating ir-inhibin concentrations occurred during the process of ovulation, followed by a second abrupt decline. After the decline, plasma concentrations of ir-inhibin remained low during the luteal phase. Plasma estradiol-17beta concentrations followed a profile similar to that of ir-inhibin, except during ovulation, and these two hormones were positively correlated throughout the estrous cycle. Plasma FSH concentrations were inversely related to ir-inhibin and estradiol-17beta. These findings suggest that the dimeric inhibin is mainly secreted by the granulosa cells and the theca cells of large follicles; granulosa cells of small follicles may secrete inhibin alpha subunit, and estradiol-17beta is secreted by the granulosa cells of only large follicles in mares. 相似文献
93.
Shield Tunnel Construction in Centrifuge 总被引:3,自引:0,他引:3
Toshi Nomoto Shinichiro Imamura Toshiyuki Hagiwara Osamu Kusakabe Nariaki Fujii 《Canadian Metallurgical Quarterly》1999,125(4):289-300
A large number of centrifuge model tests for simulating the shield construction process in dry sand was carried out by using a newly developed 100 mm diameter miniature shield tunnel. Different construction processes were modeled by three series of tests. A “buried tube test” was conducted to measure the lining stress under a centrifugal acceleration, a “tail void test” simulated the process of tail void formation only, and a “shield test” dealt with the complete process of shield construction. Lining stresses, transverse and longitudinal surface settlements, and earth pressures around the tunnel were simultaneously measured during advancement of the shield at a centrifugal acceleration of 25g. The lining stress at the crown elevation was well predicted by Terzaghi's loosening earth pressure. From the comparison with the recent field measurements and the comparative results of three series of tests, it was confirmed that the shield construction process was successfully simulated in a centrifuge. An experimental formula for estimating the surface settlement above the shield was deduced by a function of tail void thickness and cover-to-diameter ratio. 相似文献
94.
PD Adams X Li WR Sellers KB Baker X Leng JW Harper Y Taya WG Kaelin 《Canadian Metallurgical Quarterly》1999,19(2):1068-1080
Stable association of certain proteins, such as E2F1 and p21, with cyclin-cdk2 complexes is dependent upon a conserved cyclin-cdk2 binding motif that contains the core sequence ZRXL, where Z and X are usually basic. In vitro phosphorylation of the retinoblastoma tumor suppressor protein, pRB, by cyclin A-cdk2 and cyclin E-cdk2 was inhibited by a short peptide spanning the cyclin-cdk2 binding motif present in E2F1. Examination of the pRB C terminus revealed that it contained sequence elements related to ZRXL. Site-directed mutagenesis of one of these sequences, beginning at residue 870, impaired the phosphorylation of pRB in vitro. A synthetic peptide spanning this sequence also inhibited the phosphorylation of pRB in vitro. pRB C-terminal truncation mutants lacking this sequence were hypophosphorylated in vitro and in vivo despite the presence of intact cyclin-cdk phosphoacceptor sites. Phosphorylation of such mutants was restored by fusion to the ZRXL-like motif derived from pRB or to the ZRXL motifs from E2F1 or p21. Phospho-site-specific antibodies revealed that certain phosphoacceptor sites strictly required a C-terminal ZRXL motif whereas at least one site did not. Furthermore, this residual phosphorylation was sufficient to inactivate pRB in vivo, implying that there are additional mechanisms for directing cyclin-cdk complexes to pRB. Thus, the C terminus of pRB contains a cyclin-cdk interaction motif of the type found in E2F1 and p21 that enables it to be recognized and phosphorylated by cyclin-cdk complexes. 相似文献
95.
Masahiko Hiratani Toshihide Nabatame Yuichi Matsui Shinichiro Kimura 《Thin solid films》2002,410(1-2):200-204
Platinum thin films grown by chemical vapor deposition (CVD) using a liquid precursor of (methylcyclopentadienyl)trimethylplatinum were characterized in terms of crystallographic nature, morphology, contaminants, and their influence on electrical properties. The lattice constant of these CVD films (3.91–3.92 Å) is smaller than that of bulk platinum. A high oxygen contaminant is observed, irrespective of the oxygen ratio during growth. A film grown at low oxygen content consists of randomly oriented micro-grains and contains a large amount of carbon contaminants. When the film is grown under oxidative conditions, it shows a 111-textured cylindrical morphology with increasing thickness. The electric resistivity is higher than the bulk standard, and it increases with decreasing oxygen ratio during the film growth. These results indicate that the carbon contaminant causes the randomly oriented micro-grains and contributes to the high residual resistivity. 相似文献
96.
Mitsugi Yamaguchi Kazuo Nakanishi Kazuya Ohmatsu Shinichiro Meguro Yoshio Kobayashi 《Electrical Engineering in Japan》1992,112(4):33-44
The superconducting field winding of the 70-MW classhigh-response excitation superconducting generator requires a maximum operation current of 4.5 kA at the field of 6 T and needs to allow the field change of 10 T/s. In addition, superconductors have to meet the requirements of saddle-shape winding in the rotor slot and require the mechanical strength withstanding the centrifugal force as well as electromagnetic force. The developed conductor has the configuration of double stranded cable, consisting of NbTi, Cu and CuNi. An optimization was made, taking into account the requirement of low ac loss and high current density. The critical current of 13.6 kA was achieved at the field of 6 T and the ac loss was 6.9 kW/m3. The developed low-loss high-current density superconductor will be able to be applied to the field winding of the 70-MW class high-response excitation superconducting generator. 相似文献
97.
EDM machinability of SiCw/Alcomposites 总被引:1,自引:0,他引:1
Machinability of high temperature composites was investigated. Target materials, 15 and 25 vol % SiC whisker-2124 aluminium composites, were machined by electrodischarge sinker machining (EDM) and diamond saw. The machined surfaces of these metal matrix composites were examined by scanning electron microscopy (SEM) and profilometry to determine the surface finish. Microhardness measurements were also performed on the as-machined composites. 相似文献
98.
Efficient conditional transgene expression in hepatitis C virus cDNA transgenic mice mediated by the Cre/loxP system 总被引:1,自引:0,他引:1
T Wakita C Taya A Katsume J Kato H Yonekawa Y Kanegae I Saito Y Hayashi M Koike M Kohara 《Canadian Metallurgical Quarterly》1998,273(15):9001-9006
Conditional gene expression has greatly facilitated the examination of the functions of particular gene products. Using the Cre/loxP system, we developed efficient conditional transgene activation of hepatitis C virus (HCV) cDNA (nucleotides 294-3435) in transgenic mice. Efficient recombination was observed in transgenic mouse liver upon intravenous administration of adenovirus that expresses Cre DNA recombinase. After transgene activation, most hepatocytes were stained with anti-core polyclonal antibody, and 21-, 37-, and 64-kDa proteins were detected by Western blot analysis in liver lysates using anti-core, E1, and E2 monoclonal antibodies, respectively. Serum core protein was detected in transgenic mice 7 days after transgene activation with concurrent increases in serum alanine aminotransferase levels. Subsequently, an anti-core antibody response was detected 14 days after infection. Furthermore, a CD4 and CD8 positive cell depletion assay normalized both the serum alanine aminotransferase increases and pathological changes in the liver. These results suggest that HCV proteins are not directly cytopathic and that the host immune response plays a pivotal role in HCV infection. Thus, this HCV cDNA transgenic mouse provides a powerful tool with which to investigate the immune responses and pathogenesis of HCV infection. 相似文献
99.
A novel fitting procedure is proposed for a better determination of H2 rovibrational distribution from the Fulcher-a band spectroscopy. We have recalculated the transition probabilities and the results show that they deviate from Franck-Condon approximation especially for the non-diagonal transitions. We also calculated the complete sets of vibrationally resolved crosssections for electron impact d3∏u- X3∑g transition based on the semi-classical Gryzinski theory.An example of experimental study confirms that current approach provides a tool for a better diagnostics of H2 rovibrational distribution in electronic ground state. 相似文献
100.
Thermomechanical behavior of TiNi shape memory alloy fiber reinforced 6061 aluminum matrix composite 总被引:2,自引:0,他引:2
K. Hamada J. H. Lee K. Mizuuchi M. Taya K. Inoue 《Metallurgical and Materials Transactions A》1998,29(13):1127-1135
The processing and thermomechanical behaviors of TiNi shape memory alloy (SMA) fiber-reinforced 6061 Al matrix smart composites
are investigated experimentally and analytically. Optimum processing conditions of hot pressing temperature and pressure are
identified. Composite yield stresses are observed to increase with an increase in the volume fraction of TiNi fiber and prestrain
given to the composites. An analytical model for thermomechanical behavior of the composites is developed by utilizing an
exponential type of SMA constitutive model. The model predicts an increase in the composite yield stress with an increase
in prestrain. It is found that the key parameters affecting the composite yield stress are the fiber volume fraction, prestrain,
and matrix heat treatment. The predictions are in a reasonably good agreement with the experimental results. 相似文献