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排序方式: 共有856条查询结果,搜索用时 15 毫秒
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D. Dietrich ÖVE H. Reiter Th. Sauter H. -J. Schweinzer 《e & i Elektrotechnik und Informationstechnik》1997,114(5):225-230
The past decade may be regarded as the phase of the fundamental developments in fieldbus systems that were based on the OSI model. Today we are entering a second stage. It is the objective of this issue to present the current state and where the further developments will lead to. This introductory article is intended to give an overview on the subject. 相似文献
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M. Muhr ÖVE S. Pack ÖVE H. Haidvogl F. Kreyca 《e & i Elektrotechnik und Informationstechnik》1997,114(11):680-686
Recently appeared defects on high voltage cables have required an urgent evaluation of the impact of lightning strikes necessary. In some cases overvoltages between the copper wire screen of the cable and earth may appear which cause damages of the cablesheath. Field measurements with a classification of the voltage impulses at the copper wire screen have been made to evaluate the number of events. Additionally a numerical model was developed to study the effects of atmospheric discharges on underground cables with emphasis to the influence on the cablesheath. This numeric method was also applied to estimate the effectiveness of different protection arrangements. This contribution presents evaluation methods for overvoltages of cables and a model used firstly for calculating the stress caused by differential voltages and secondly to determinate the influence of protection measures. 相似文献
5.
MJ de Gortari BA Freking SM Kappes KA Leymaster AM Crawford RT Stone CW Beattie 《Canadian Metallurgical Quarterly》1997,28(4):274-290
We report the evaluation of 1036 bovine microsatellite primer pairs for their suitability as linkage markers in sheep. Approximately 58% (605/1036) of bovine primer pairs amplified a locus in sheep. Sixty-seven per cent (409/605) of amplified loci were detected as polymorphic. Marker heterozygosity, allele number and range of allele sizes were significantly lower in sheep than cattle sampled in this study. However, median fragment size was similar. These data suggest that high-resolution comparative linkage maps between closely related species can be constructed relatively efficiently. 相似文献
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The mechanical properties of totally ischemic hearts of inbred albino rats were studied. The ischemic myocardium was found to be more sensitive to cyclic loads. Energy deficient contracture of cardiomyocytes is a factor which increases the resistance of the myocardium to mechanical effects. 相似文献
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We used a new injury device that produces consistent spinal cord contusion injuries (T8) in rats to compare the behavioral and histologic effects of methylprednisolone sodium succinate (MPSS) administration, the clinical standard of therapy after acute spinal cord injury (ASCI), with the 21-aminosteroid, U-74006F (U74), and the TRH analogue, YM-14673 (YM), at different trauma doses. Three sequential experiments were conducted: Experiment 1. U74 (3.0/1.5/1.5 mg/kg; 10/5/5 mg/kg; 30/15/15 mg/kg), MPSS (30/15/15 mg/kg), or vehicle were administered intravenously (i.v.) at 5 min, 2 and 6 h after the injury (n = 8/group). U74 (10/5/5 mg/kg) and MPSS animals scored better than controls (Days 8-43) in open field walking (OFW); no other differences were seen between groups. Experiment 2. Dose-response evaluation of MPSS determined more effective doses. Groups (n = 16) receiving 30/30/30/30 mg/kg and 60/60/60/60 mg/kg i.v. at 5 min and 2, 4, and 6 h after the injury had better OFW scores than controls (Days 8-29; Day 29). Both groups performed better than controls (Days 8-29) on inclined plane (IP); 30 mg/kg animals scored higher on Day 29. Percentage tissue spared (%TS) at the lesion center was greater for 60 mg/kg animals (23.4%) than controls (17.3%). Experiment 3. Compounds were administered as in experiment 2 (n = 15/group); MPSS (60/30/30/30 mg/kg) and YM (1/1/1/1 mg/kg and 1 mg/kg/day ip) were most effective. YM and MPSS combination produced no additive effects. YM animals scored better than MPSS and control animals in OFW (Days 8-29) and better than controls on IP (Days 8-29; Day 29) and grid walking (Day 29). MPSS animals scored better than controls on IP (Days 8-29). YM and MPSS groups had greater %TS than controls. This series of experiments demonstrates the utility of this injury model and simple behavioral measures for preclinical assessment of pharmacologic agents. Under these experimental conditions, U74 demonstrated equivalent efficacy to MPSS, and YM demonstrated greater efficacy than MPSS in the treatment of ASCI. 相似文献
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Ohne Zusammenfassung 相似文献
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AA Ovchinnikov VE Tsvettsikh BA Berdichevski? VN Lykov VR Suktanbaev AV Murychev 《Canadian Metallurgical Quarterly》1996,20(4):7-9
Through TCD test, observation on the blood flow dynamics change before and after treatment with 31 cases of the child cerebral atrophy was made. It is found that scalp therapy is able to speed up the blood flow of part artery, especially increase the even blood flow speed of MCA, ACA obviously (P < 0.05), which preliminary shows the mechanism of scalp therapy for child cerebral atrophy mean while. It is found that scalp therapy also has the function to restrain epilepsy. 相似文献
10.
M. Hofbaur ÖVE N. Dourdoumas ÖVE 《e & i Elektrotechnik und Informationstechnik》1997,114(7-8):371-379
Qualitative-quantitative simulation is one of the most productive and promising research areas in Artificial Intelligence to emerge in recent years. This method provides an elegant way for an exhaustive analysis of uncertain dynamic systems. The application of the qualitative-quantitative simulation is shown in this paper. The important question about the stability of a quanlitatively described dynamical system is solved by a novel analytic method. 相似文献