Double-crossed-step-stress(DCSS) accelerated life test(ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost...Double-crossed-step-stress(DCSS) accelerated life test(ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost, a double-synchronous-step-stress(DSSS) ALT method which combines a double-synchronous-step-downstress(DSSDS) ALT method and a double-synchronous-step-up-stress(DSSUS) ALT method is proposed. The accelerated stresses decrease and increase in a synchronous way with one step in the DSSDS-ALT and DSSUSALT methods, respectively. Monte Carlo method is adopted to simulate the two methods, and the validity and efficiency of them are demonstrated by the simulation results. In addition, a comparison analysis of efficiency between DSSDS-ALT method and DSSUS-ALT method is carried out. The result shows that the DSSDS-ALT method compared with the DSSUS-ALT method can significantly improve the test efficiency under the same test condition.展开更多
The performance degradation rates of the missile tank are generally time-varying functions uneasily evaluated by general classical evaluation methods. This paper develops a segmented nonlinear accelerated degradation ...The performance degradation rates of the missile tank are generally time-varying functions uneasily evaluated by general classical evaluation methods. This paper develops a segmented nonlinear accelerated degradation model （SNADM） based on the equivalent method of accumulative damage theory, which tackles the problem that product life is difficult to be determined with degradation rate being a function of the variable of time. A segmented expression of the function of population accumulative degradation is derived. And combined with nonlinear function, an accelerated degradation function, i.e., SNADM is obtained. The parameters of the SNADM are identified by numerical iteration, and the statistical function of degradation track is extrapolated. The reliability function is determined through the type of random process of the degradation distribution. Then an evaluation of product storage life is undertaken by combining the statistical function of degradation track, reliability function and threshold. An example of a missile tank undergoes a step-down stress accelerated degradation test （SDSADT）, in which the results with the SNADM and the classical method are evaluated and compared. The technology introduced is validated with the resultant coincidence of both evaluated and field storage lives.展开更多
目的观察依托咪酯(etomidate,Eto)所致遗忘作用与GABAA受体或NMDA受体的关系。方法小鼠腹腔注射Eto(3 mg.kg-1),建立遗忘模型,在跳台实验和避暗实验中分别观察不同剂量的荷包牡丹碱或NMDA侧脑室注射对遗忘小鼠错误次数(error times,ET)...目的观察依托咪酯(etomidate,Eto)所致遗忘作用与GABAA受体或NMDA受体的关系。方法小鼠腹腔注射Eto(3 mg.kg-1),建立遗忘模型,在跳台实验和避暗实验中分别观察不同剂量的荷包牡丹碱或NMDA侧脑室注射对遗忘小鼠错误次数(error times,ET)、跳台潜伏期(step down la-tency,SDL)、步入潜伏期(step through latency,STL)的影响。结果侧脑室注射荷包牡丹碱(2、4μg)可减少Eto所致遗忘小鼠的ET,延长SDL和STL。侧脑室注射NMDA对Eto所致遗忘小鼠的ET、SDL和STL均无影响。结论GABAA受体是依托咪酯所致遗忘作用的重要靶位,NMDA受体则不是其作用靶位。展开更多
基金the National Natural Science Foundation of China(Nos.51265025 and 51665029)
文摘Double-crossed-step-stress(DCSS) accelerated life test(ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost, a double-synchronous-step-stress(DSSS) ALT method which combines a double-synchronous-step-downstress(DSSDS) ALT method and a double-synchronous-step-up-stress(DSSUS) ALT method is proposed. The accelerated stresses decrease and increase in a synchronous way with one step in the DSSDS-ALT and DSSUSALT methods, respectively. Monte Carlo method is adopted to simulate the two methods, and the validity and efficiency of them are demonstrated by the simulation results. In addition, a comparison analysis of efficiency between DSSDS-ALT method and DSSUS-ALT method is carried out. The result shows that the DSSDS-ALT method compared with the DSSUS-ALT method can significantly improve the test efficiency under the same test condition.
文摘The performance degradation rates of the missile tank are generally time-varying functions uneasily evaluated by general classical evaluation methods. This paper develops a segmented nonlinear accelerated degradation model （SNADM） based on the equivalent method of accumulative damage theory, which tackles the problem that product life is difficult to be determined with degradation rate being a function of the variable of time. A segmented expression of the function of population accumulative degradation is derived. And combined with nonlinear function, an accelerated degradation function, i.e., SNADM is obtained. The parameters of the SNADM are identified by numerical iteration, and the statistical function of degradation track is extrapolated. The reliability function is determined through the type of random process of the degradation distribution. Then an evaluation of product storage life is undertaken by combining the statistical function of degradation track, reliability function and threshold. An example of a missile tank undergoes a step-down stress accelerated degradation test （SDSADT）, in which the results with the SNADM and the classical method are evaluated and compared. The technology introduced is validated with the resultant coincidence of both evaluated and field storage lives.
文摘目的观察依托咪酯(etomidate,Eto)所致遗忘作用与GABAA受体或NMDA受体的关系。方法小鼠腹腔注射Eto(3 mg.kg-1),建立遗忘模型,在跳台实验和避暗实验中分别观察不同剂量的荷包牡丹碱或NMDA侧脑室注射对遗忘小鼠错误次数(error times,ET)、跳台潜伏期(step down la-tency,SDL)、步入潜伏期(step through latency,STL)的影响。结果侧脑室注射荷包牡丹碱(2、4μg)可减少Eto所致遗忘小鼠的ET,延长SDL和STL。侧脑室注射NMDA对Eto所致遗忘小鼠的ET、SDL和STL均无影响。结论GABAA受体是依托咪酯所致遗忘作用的重要靶位,NMDA受体则不是其作用靶位。
