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61.
Determining torque and current at locked rotor and various slips during the acceleration test on a synchronous machine is very tedious and time consuming. Induction and synchronous machines behave similarly during acceleration except that synchronous machine acceleration can include a pulsation torque. Because of the salient poles, conditions exist where the synchronous motor has minimum torque at quadrature axis and maximum torque at direct axis during locked rotor or stall. Since synchronous machines do not have large numbers of rotor bars in the amortisseur winding, like the induction motor has in the squirrel cage, their stall times tend to be shorter. Due to the shorter stall time and large starting torque, locked-rotor torque and current are generally determined from acceleration tests conducted at reduced voltage rather than by tests at stand-still. Data showing that saturation effects impact both torque and current are presented in this paper. The data shows that the voltage index that has to be applied to the torque and current measured at reduced voltage varies with speed and can be obtained from a series of acceleration tests 相似文献
62.
Peripheral T cell lymphoma encompasses lymphomas with a variety of histologic appearances and clinical patterns. Recently, it has been suggested that almost all of the histologic features described under the name of polymorphic reticulosis(PR), lethal midline granuloma, and midline malignant reticulosis can be included in those generally described for malignant lymphomas of peripheral T cell origin(PTCL). There have been few studies of pathogenesis or tissue damage mechanism in PR patients. The need for a precise mechanism for tissue damage has important therapeutic implications. Using immunohistochemical methods with polyclonal anti IL-6 antibody, the authors describe 5 cases of PR with clinically and pathologically typical PR demonstrating a high expression of IL-6. According to classification, 2 cases of grade 1 PR showed the highest expressions, and 2 cases of grade 2 PR with atypical lymphoid cells showed moderate activity, but one case progressed into frank lymphoma(grade 3) and lost IL-6 expression. This strongly implies that some cases of PR have a different mechanism of tissue damage from frank PTCL, despite the one disease spectrum. Further studies on more cases may help clarify the pathogenesis. 相似文献
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Abstract: A fuzzy reasoning algorithm is presented in this paper. It is based on the concept of a generalised fuzzy production rule that adds new conjunctions such as ADD and REL to the usual AND and OR conjunctions for the linkage of premises in conventional rules. A definition is given for weights and related factors, to express and measure a relation between the premises. A formal representation for fuzzy premises is presented, together with the introduction of a fuzzy match method. Multiple thresholds are used to convert the uncertainty measures of reasoning results into linguistic variables. We have applied the fuzzy reasoning algorithm to a frame-based hybrid expert system tool. An object-oriented approach is used in implementing the system. Some results of the application are presented and discussed. 相似文献
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