排序方式: 共有20条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
K Avasarala C Case M Wienecke V Zeigler L Lai P Gillette 《Canadian Metallurgical Quarterly》1998,21(12):2677-2680
Dual chamber pacing was shown to decrease left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy 30 years ago. We report early results of AV sequential pacing from the LV apex in a patient with transposition of the great arteries who is post-Senning procedure. LVOT obstruction resulted from septal deviation and systolic anterior motion of the mitral valve. Pacing was indicated for sinus node dysfunction. AV sequential pacing with a short optimal AV interval of 60 ms demonstrated a 45% reduction in the degree of LVOT obstruction. This article suggests that LVOT obstruction after the Senning procedure can be palliated by asynchronous septal contraction induced by AV sequential pacing, even if the activation is from LV apex, and avoid or postpone surgery in selected situations. 相似文献
5.
Phosphate glasses containing mixed Cu2+/Ni2+ and Cu2+/Co2+ oxides have been examined. A pronounced decrease in the optical absorption at 830 nm due to the Cu2+ ions is observed as the CuO in the glasses is gradually replaced by NiO or CoO and the decrease is accompanied by a pronounced decrease in the strength of the electron spin resonance (ESR) signal at 9.52 GHz. By combining the ESR and optical absorption data it is concluded that the decrease in concentration of Cu2+ ions in phosphate glasses may be due to an oxidation-reduction mechanism between two valency states of the two different transition metals, of the form Cu2++Ni+Cu++Ni2+ and Cu2++Co+Cu++Co2+. 相似文献
6.
7.
8.
9.
Photocatalytic degradation of monocrotophos pesticide--an endocrine disruptor by magnesium doped titania 总被引:1,自引:0,他引:1
Mg-doped TiO(2) with different Mg concentrations were prepared using sol-gel method and characterized by XRD, UV-visible, XPS, SEM and FT-IR. The XRD results revealed that Mg(2+) goes into the TiO(2) lattice. SEM images of the doped and pure TiO(2) indicated that there is a smaller particle size for the doped catalyst compared to that of the pure TiO(2). UV-visible absorption spectra indicated that upon doping with Mg(2+) ion, the catalyst exhibits absorption in visible region. FT-IR and XPS spectra demonstrated that the presence of Mg(2+) ion in the TiO(2) lattice as substitutional dopant. Photocatalytic activity of doped TiO(2) has been evaluated by degradation of the monocrotophos (MCP) pesticide. The effect of solution pH, catalyst dosage and initial concentration of MCP on the photocatalytic activity of Mg-doped TiO(2) with different loadings was studied. It was observed that the rate of degradation of MCP over Mg-doped TiO(2) is better than Pure TiO(2) and Degussa P-25. 相似文献
10.
Customer-Driven Sensor Management 总被引:1,自引:0,他引:1
Customer-driven sensor management advocates applying e-commerce concepts and advances to sensor management. In e-commerce, customer wants essentially drive the production process. Sensor management has traditionally followed a much less capitalistic process, producing information "goods" based on predefined system goals and priorities. We explore here some of the possibilities and advantages of incorporating a customer-driven market-based approach to sensor management.This article is part of a special issue on Self-Managing Systems. 相似文献