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991.
Translated from Metallurg, Vol. 39, No. 6, p. 45, June, 1995.  相似文献   
992.
This article presents recent techniques in the field of dual-polarization printed antennas for designing shielded radiating structures with high-quality performances in terms of cross-polarization level and input-port isolation. The use of gridded patches provides a natural solution to filtering surface currents and is of key importance in limiting inter-element coupling in arrays. Experimental results obtained on various designs are presented  相似文献   
993.
A detailed review of SiGe epitaxial base technology is presented, which chronicles the progression of research from materials deposition through device and integration demonstrations, culminating in the first SiGe integrated circuit application. In part I of this paper, the requirements and processes for high-quality SiGe film preparation are discussed, with emphasis on fundamental principles. A detailed overview of SiGe HBT device design and implications for circuit applications is then presented  相似文献   
994.
995.
Since foodborne diseases, especially those caused by bacteria, have become an increasingly important public health problem, the Authors conducted a survey in order to evaluate the organization of, and the intervention carried out by, six Public Health Services in the Lombardia region, after reports of foodborne diseases outbreaks. Lack of correct methodology was detected, not to mention the usual omission of epidemic curves and attack rates. Besides, too many microbiological tests were made and it took too much time to take care of and to report the outbreaks to Regional and National Health Authorities. Forty-one outbreaks were examined: 415 cases occurred (AR: 28.7%), most of which home-made food-related. In 25 outbreaks the suspected food vehicles were eggs or fish, but only 5 of them were confirmed by laboratory tests. Salmonella enterica, either serovar Eenteritidis or group D, appeared responsible for 26 of the outbreaks [corrected].  相似文献   
996.
997.
Recent developments of stability control in mines, essentially based on Ge-doped fiber Bragg gratings (FBG) are reported including results about the different aspects of the system: accurate characterizations of FBG, sensor network topology and multiplexing method, user interface design and sensor packaging  相似文献   
998.
We report a detailed mapping of a 2-D dopant profile on a fully processed industrial sample with large dynamic range and high spatial resolution by utilizing a dopant-selective etching process and Atomic Force Microscopy. The experimental results show excellent agreement with those obtained from SRP and SIMS as corroborative methods. We also discuss the most critical factors which influence the applicability, reproducibility, and reliability of this method  相似文献   
999.
A stability analysis of TE polarized nonlinear guided waves in multiple-quantum-well waveguides is presented. In particular, a scalar finite element approach has been used in order to numerically investigate symmetrical as well as asymmetrical field distributions and their properties. For high input power, the analysis reveals the stable and the unstable nature of asymmetrical and symmetrical multiple quantum well waveguide solutions. Similar features to single linear film bounded by nonlinear media are pointed out. The limits of the homogeneous slab approximation are discussed  相似文献   
1000.
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