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1.
Asymptotic stability of finite-dimensional linear continuous-time periodic (FDLCP) systems is studied by harmonic analysis. It is first shown that stability can be examined with what we call the harmonic Lyapunov equation. Another necessary and sufficient stability criterion is developed via this generalized Lyapunov equation, which reduces the stability test into that of an approximate FDLCP model whose transition matrix can be determined explicitly. By extending the Gerschgorin theorem to linear operators on the linear space l2, yet another disc-group criterion is derived, which is only sufficient. Stability of the lossy Mathieu equation is analyzed as a numerical example to illustrate the results 相似文献
2.
Ikeda S. Ohta H. Hideo Miura Hagiwara Y. 《Semiconductor Manufacturing, IEEE Transactions on》2003,16(4):696-703
An ideal fabrication process is designed to minimize mechanical stress in semiconductor devices and to improve device reliability. Mechanical stress levels were predicted by in-house simulations supported by a thin-film database. These stress levels were correlated with stress-induced defects by TEM analysis supported by fail bit addressing on matured megabit SRAMs. Amorphous-doped silicon film with various annealing temperatures were used for the gate electrode to change the mechanical stress in devices and to get the direct relationship between predicted stress levels and stress related defects. The authors describe brief guidelines for suppressing dislocations in the small geometry shallow-trench isolation process utilizing this system. Polysilicon thickness in the W-polycide gate electrode is designed to minimize mechanical stress in the gate oxide and to suppress the gate oxide failure in probe and class tests. Moreover, critical stress generates dislocations during post source/drain ion implantation anneal obtained by a ball indentation method. This indicated that lower temperature anneal is effective in suppressing the dislocations. A two-step anneal was introduced to suppress dislocations and to enable higher ion activation. 相似文献
3.
4.
We measured the activity of mitogen-activated protein (MAP) kinases, enzymes believed to be involved in the pathway for cell proliferation, in rat aortic strips with or without endothelium, and examined effects of angiotensin receptor antagonists, endothelin receptor antagonists and nitric oxide (NO)-related agents. Endothelium removal produced an activation of MAP kinase activity in the strips, whereas the enzyme activity was not affected in the adventitia. The MAP kinase activation was inhibited by either the angiotensin AT1 receptor antagonist losartan or the endothelin ETA receptor antagonist BQ 123. The combination of both antagonists caused an additive inhibition. The angiotensin AT2 receptor antagonist PD 123,319 and the endothelin ETB receptor antagonist BQ 788 did not affect the MAP kinase activation. The NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) caused an activation of MAP kinase in the endothelium-intact aorta and the MAP kinase activation was inhibited by losartan or BQ123. The NO releaser nitroprusside inhibited the MAP kinase activation induced by endothelium removal or angiotensin II. These results suggest that even in isolated arteries, NO of endothelial origin tonically exert MAP kinase-inhibiting effects and endogenous angiotensin II and endothelins in the media are tonically released to cause MAP kinase-stimulating effects in medial smooth muscle. 相似文献
5.
Masashi Shou Hiroyuki Takekawa Dong-Ying Ju Tokio Hagiwara Da-ling Lu Ken-ichi Tanaka 《Catalysis Letters》2006,108(3-4):119-124
Catalytic activity of a 1 wt% Au/TiO2 catalyst is markedly improved by loading a large amount of FeOx, on which the oxidation of CO in excess H2 is selectively promoted at temperature lower than 60 °C. Oxidation of CO with O2 on the FeOx/Au/TiO2 catalyst is markedly enhanced by H2, and H2O moisture also enhances the oxidation of CO but its effect is not so large as the promotion by H2. We deduced that activation of Au/TiO2 catalyst by loading FeOx is not caused by the size effect of Au particles but a new reaction path via hydroxyl carbonyl intermediate is responsible
for the superior activity of the FeOx/Au/TiO2 catalyst. 相似文献
6.
High oleic acid oil suppresses lung tumorigenesis in mice through the modulation of extracellular signal-regulated kinase cascade 总被引:2,自引:0,他引:2
Yamaki T Yano T Satoh H Endo T Matsuyama C Kumagai H Miyahara M Sakurai H Pokorny J Shin SJ Hagiwara K 《Lipids》2002,37(8):783-788
This study was undertaken to estimate the effect of dietary high oleic acid oil (OA) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone
(NNK)-induced lung tumorigenesis in mice. Diet containing 10% oil was fed to mice through experimental periods. On day 30
after NNK injection (100 mg/kg body weight, i.p.), the treatment increased the level of prostaglandin E2 (PGE2) as well as proliferating cell nuclear antigen, a marker of cell proliferation in a high linoleic acid oil (LA)-fed group
but not in an OA-fed group. The NNK treatment also induced the activation of an extracellular signal-regulated kinase (Erk)
cascade (Erk, Mek and Raf-1) in an LA-fed group. On the other hand, OA feeding abolished the NNK-induced activation of the
Erk cascade. In conjugation with these events, OA feeding reduced lung tumor incidence and tumor multiplicity (percentage
of mice with tumors) in mice compared with LA feeding at the 20th experimental week. These results suggest that OA suppresses
lung tumorigenesis and that this suppression is correlated with the inhibition of PGE2 production and inactivation of the Erk cascade. 相似文献
7.
The dynamic mechanical relaxation of non-crystalline poly(aryl ether-ether-ketone) PEEK and the one irradiated with electron beam were studied. The three distinct γ, β, α′ relaxation maxima were observed in unirradiated PEEK from low to high temperature. It was revealed from the study on the irradiation effects that three different molecular processes are overlapped in γ relaxation peak, i.e., molecular motion of water bound to main chain (peak temperature; at ?100°C), local motion of main chain (at ?80°C), and local mode of the aligned and/or oriented moiety (at ?40°C). The β relaxation connected with the glass transition occurred at 150°C and it shifted to higher temperature by irradiation. The α′ relaxation which can be attributed to rearrangement of molecular chain due to crystallization was observed in unirradiated PEEK ~ 180°C and its magnitude decreased with the increase in irradiation dose. This effect indicates the formation of structures inhibiting crystallization such as crosslinking and/or short branching during irradiation. A new relaxation, β′, appeared in the temperature range of 40° to 100°C by irradiation and its magnitude increased with dose. This relaxation was attributed to rearrangement of molecular chain from loosened packing around chain ends, which were introduced into the non-crystalline region by chain scission under irradiation, to more rigid molecular packing, From these observations, we proposed that deterioration in mechanical properties of non-crystalline PEEK by high energy electron beam was brought about not only by chain scission but structural changes such as crosslinking and/or branching in the main chain. 相似文献
8.
Masahiro Kato Kazuaki Nakagawa Kenji Essaki Yukishige Maezawa Shin Takeda Ryosuke Kogo Yoshikazu Hagiwara 《International Journal of Applied Ceramic Technology》2005,2(6):467-475
We have discovered a series of lithium-containing oxides that immediately react with ambient carbon dioxide (CO2 ) up to 700°C. The products react and return reversibly to the oxides at a temperatures higher than about 700°C. The absorption capacity surpasses that of other CO2 absorbents by a factor of 10. Utilizing these absorbents, the possibility of a CO2 separation system that operates at around 500°C is proposed. It is generally believed that a CO2 separation process operable at temperatures higher than 500°C has the special benefit of a small energy penalty. Moreover, the absorption also proceeds at ambient temperature in the atmospheric environment. This property offers the possibility of many other applications, such as air cleaners or cartridges. Therefore, we think these materials have the potential to make a valuable contribution to the realization of CO2 emission control. 相似文献
9.
A case of phacomatosis pigmentovascularis (PPV) in a 6-year-old girl with Sturge-Weber syndrome, pyogenic granuloma, and other complications is described. It is relatively rare that a complete form of Sturge-Weber syndrome was associated with PPV. A review of the literature on PPV, focusing on total number of reported cases and etiological speculations, is presented. To our knowledge, a total of 118 cases of PPV, including the present one, have been reported to date. Regardless of many speculations, the true etiology remains unknown. The average "density" of mast cells (MCs) per mm2 appearing in the central region of the pyogenic granuloma was calculated to be 86.3/mm2 and that in the adjacent nevus flammeus was 37.9/mm2. The "density" of mast cells in pyogenic granuloma separately calculated from ten other cases was 105.5 +/- 28.6/mm2 (mean +/- SD), compared with that in normal skin, 6.85 +/- 4.9/mm2 (n = 20). There was a significant difference between the two, indicating that MCs are closely associated with angiogenesis in pyogenic granuloma. 相似文献