Structural design and tests on the characteristics of the SF6 gas switch with a small gap are presented. This kind of switch often works under high pressure and nanosecond pulse for getting pulse with faster risetime....Structural design and tests on the characteristics of the SF6 gas switch with a small gap are presented. This kind of switch often works under high pressure and nanosecond pulse for getting pulse with faster risetime. The breakdown voltage and breakdown delay of a number of switches with different geometries, gas pressures and pulse waveforms were investigated. Experimental results suggested that the breakdown voltage increases linearly with the gas pressure, and the breakdown delay decreases with an increase in the gas pressure and a reduction in the gap distance of the switch under the same applied pulse. By using this kind of switch with a gap of 3 mm as a peaking switch, a pulse generator can provide an output voltage with a peak voltage of 300 kV and a risetime of 3 ns on a resistance load of 150Ω.展开更多
Objectives: It is important to know what patient reported outcome measure (PROM) scores relate to a meaningful change in health status across time. The aim of this study was to investigate the minimally important diff...Objectives: It is important to know what patient reported outcome measure (PROM) scores relate to a meaningful change in health status across time. The aim of this study was to investigate the minimally important difference (MID) of the Diabetes Health Profile (DHP-18), EQ-5D and SF-6D in a Type 1 and Type 2 diabetes patient sample. Methods: A longitudinal dataset including a UK community sample of people with Type 1 and Type 2 diabetes was used for the analysis. A combination of anchor and distribution methods was used to investigate the MID. For the anchor based method, a global health change indicator was used if it correlated with the PROM scores at baseline and follow up. To calculate the anchor based MID, the change in PROM score for those reporting no change on the anchor was subtracted from those reporting small change. For the distribution based estimation, the 1 Standard Error of Measurement, 0.5 and 0.33 standard deviation methods were used. Results: The anchor was not correlated with the DHP-18 dimensions so was only used to estimate MID values for the EQ-5D and SF-6D. For the DHP-18, MID estimates for the Psychological Distress domain range from 6.99 to 10.59, the Barriers to Activity domain range from 6.48 to 9.89, and the Disinhibited Eating domain range from 7.52 to 11.39. The EQ-5D estimations range from 0.058 to 0.158, and the SF-6D estimations range from 0.038 to 0.081. The 0.5 SD and 1SEM estimations are of a similar magnitude across the three measures. Conclusions:This study has derived a range of values for each measure that may correspond to an important change in health status. The MID values may guide researchers who are using the measures as part of their assessment of both Type 1 and Type 2 patients with diabetes mellitus.展开更多
基金supported by National Natural Science Foundation of China (No. 50437030)
文摘Structural design and tests on the characteristics of the SF6 gas switch with a small gap are presented. This kind of switch often works under high pressure and nanosecond pulse for getting pulse with faster risetime. The breakdown voltage and breakdown delay of a number of switches with different geometries, gas pressures and pulse waveforms were investigated. Experimental results suggested that the breakdown voltage increases linearly with the gas pressure, and the breakdown delay decreases with an increase in the gas pressure and a reduction in the gap distance of the switch under the same applied pulse. By using this kind of switch with a gap of 3 mm as a peaking switch, a pulse generator can provide an output voltage with a peak voltage of 300 kV and a risetime of 3 ns on a resistance load of 150Ω.
文摘Objectives: It is important to know what patient reported outcome measure (PROM) scores relate to a meaningful change in health status across time. The aim of this study was to investigate the minimally important difference (MID) of the Diabetes Health Profile (DHP-18), EQ-5D and SF-6D in a Type 1 and Type 2 diabetes patient sample. Methods: A longitudinal dataset including a UK community sample of people with Type 1 and Type 2 diabetes was used for the analysis. A combination of anchor and distribution methods was used to investigate the MID. For the anchor based method, a global health change indicator was used if it correlated with the PROM scores at baseline and follow up. To calculate the anchor based MID, the change in PROM score for those reporting no change on the anchor was subtracted from those reporting small change. For the distribution based estimation, the 1 Standard Error of Measurement, 0.5 and 0.33 standard deviation methods were used. Results: The anchor was not correlated with the DHP-18 dimensions so was only used to estimate MID values for the EQ-5D and SF-6D. For the DHP-18, MID estimates for the Psychological Distress domain range from 6.99 to 10.59, the Barriers to Activity domain range from 6.48 to 9.89, and the Disinhibited Eating domain range from 7.52 to 11.39. The EQ-5D estimations range from 0.058 to 0.158, and the SF-6D estimations range from 0.038 to 0.081. The 0.5 SD and 1SEM estimations are of a similar magnitude across the three measures. Conclusions:This study has derived a range of values for each measure that may correspond to an important change in health status. The MID values may guide researchers who are using the measures as part of their assessment of both Type 1 and Type 2 patients with diabetes mellitus.
