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71.
M. S. Osofsky W. L. Lechter L. E. Toth E. F. Skelton A. R. Drews C. C. Kim B. Das S. B. Qadri A. W. Webb R. J. Soulen 《Journal of Electronic Materials》1995,24(12):1977-1980
Several members of a new family of (Hg,Tl)(Ba,Sr)CaCuO high temperature superconductors have been synthesized. These compounds,
which are analogs to the Hg-Ba-Ca- and Tl-Ba-Ca-layered cuprates, are multi-phased and have superconducting transition temperatures
above 100K. Several samples with a nominal composition of HgTl2Ba4Ca4Cu6Oy had Tcs near 130K. Details of the characterization of these samples are presented. 相似文献
72.
Arpad G. Toth Mikhail Tsinberg Charles W. Rhodes 《International Journal of Communication Systems》1988,1(2):65-72
High definition television (HDTV) has become a major world-wide event in the television arena. Since the early 1980s, when HDTV was first demonstrated by Japan, a number of alternative systems have emerged. These systems clearly reflect the business and political objectives of the particular countries or organizations. In North America, which is the largest single consumer market in the world, technical, business and political considerations are shaping the evolution of HDTV. This paper describes a possible advanced television (ATV) architecture for North America and defines its functional modules and corresponding interfaces. The developed model is recommended as a design tool for standardizing ATV in North America and analysing interrelationships of the functional modules on the economic basis. The paper proposes an ‘hierarchical’ ATV emission system with full NTSC compatibility and HDTV quality. Solutions are recommended for terrestrial broadcast, CATV and satellite. This work describes a total systems approach to HDTV called HDS-NA (high definition system for North America). The two emission signals of HDS-NA: HDMAC-60 and HDNTSC are characterized. RF alternatives for the terrestrial broadcast of HDTV are also discussed. 相似文献
73.
Gregory A. Toth 《Automated Software Engineering》1995,2(3):231-248
This paper describes an approach for automatically determining project risk factors based on answers to an interactive questionnaire. Stored knowledge of complex interrelationships is used to transform qualitative inputs into quantitative factors used to rank and compare identified risks. A tool called the Software Technology Risk Advisor is described which implements these techniques and provides a testbed for further refinement. 相似文献
74.
H. A. Hoff M. Rubinstein M. S. Osofsky A. K. Singh L. E. Richards W. L. Lechter L. E. Toth B. N. Das C. S. Pande 《Journal of Superconductivity》1989,2(3):351-359
A common mineralogical technique for identifying individual crystals in a heterogeneous, polycrystalline sample involves the observation at room temperature of their colors in reflected polarized light (colors of polarization). Here we present the observation that a brownish yellow (golden) color of polarization is not only characteristic of the YBa2Cu3O7 superconductor, but of the cuprate superconductors in general and is correlated with the occurrence of superconductivity. 相似文献
75.
76.
W. L. Lechter B. N. Das E. F. Skelton M. S. Osofsky L. E. Toth H. A. Hoff G. N. Kamm A. K. Singh V. LeTourneau C. S. Pande S. A. Wolf 《Journal of Superconductivity and Novel Magnetism》1988,1(2):181-190
Millimeter-sized crystals of ErBa2Cu3O7 were fortuitously grown while sintering a flat disk. It was possible to separate individual crystals from the sintered mass and measure their properties. The resistive transition and onset of magnetic transition of a single crystal was 93 K and the resistive transition width was < 1 K. Flux expulsion was observed and individual crystals could be levitated by a magnetic field. Crystals showed unusual growth features. They were heavily corrugated along the part of the crystal that grew parallel to the top surface of the disk and that coincided with thec axis of the unit cell. Crystals were characterized by X-rays, electron microscopy, and optical microscopy. 相似文献
77.
78.
KW Mahaffey CB Granger CA Toth HD White AL Stebbins GI Barbash A Vahanian EJ Topol RM Califf 《Canadian Metallurgical Quarterly》1997,30(7):1606-1610
OBJECTIVES: This study sought to evaluate the incidence of ocular hemorrhage in patients with and without diabetes after thrombolytic therapy for acute myocardial infarction. BACKGROUND: Ocular hemorrhage after thrombolysis has been reported rarely. However, there is concern that the risk is increased in patients with diabetes. In fact, diabetic hemorrhagic retinopathy has been identified as a contraindication to thrombolytic therapy without clear evidence that these patients have an increased risk for ocular hemorrhage. METHODS: We identified all suspected ocular hemorrhages from bleeding complications reported in patients enrolled in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I trial. Additional information was collected on a one-page data form. We compared the incidence and location of ocular hemorrhages in patients with and without diabetes. RESULTS: There were 40,899 patients (99.7%) with information about diabetic history and ocular bleeding. Twelve patients (0.03%) had an ocular hemorrhage. Intraocular hemorrhage was confirmed in only one patient. There were 6,011 patients (15%) with diabetes, of whom only 1 had an ocular hemorrhage (eyelid hematoma after a documented fall). The upper 95% confidence intervals for the incidence of intraocular hemorrhage in patients with and without diabetes were 0.05% and 0.006%, respectively. CONCLUSIONS: Ocular hemorrhage and, more important, intraocular hemorrhage after thrombolytic therapy for acute myocardial infarction is extremely uncommon. The calculated upper 95% confidence interval for the incidence of intraocular hemorrhage in patients with diabetes was only 0.05%. We conclude that diabetic retinopathy should not be considered a contraindication to thrombolysis in patients with an acute myocardial infarction. 相似文献
79.
80.