Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within...Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.展开更多
目的:分析早期动脉血乳酸水平及乳酸清除率对失血性低血容量休克患者预后的评估价值。方法:选取本院2015年5月-2016年6月重症监护病房(ICU)收治的失血性低血容量休克患者142例作为研究对象,根据疾病转归,将患者分为存活组和死亡组,其中...目的:分析早期动脉血乳酸水平及乳酸清除率对失血性低血容量休克患者预后的评估价值。方法:选取本院2015年5月-2016年6月重症监护病房(ICU)收治的失血性低血容量休克患者142例作为研究对象,根据疾病转归,将患者分为存活组和死亡组,其中存活组106例,死亡组36例。比较两组患者年龄、性别比例,并采用急性生理学和慢性健康评分(Acute Physiology and Chronic Health Evaluation,APACHEⅡ)评估患者的病情严重性,分别检测患者入院时及入院治疗6 h早期动脉血乳酸水平,计算患者6 h乳酸清除率,采用ROC曲线评估早期动脉血乳酸水平及乳酸清除率对患者的预后价值。结果:两组APACHEⅡ评分比较差异无统计学意义(P>0.05);存活组入院时及入院治疗6 h的动脉血乳酸浓度均低于死亡组,且存活组的乳酸清除率明显高于死亡组,比较差异均有统计学意义(P<0.05);ROC曲线分析结果显示,早期动脉血乳酸水平及乳酸清除率对失血性低血容量休克患者预后评估价值良好,当血液乳酸浓度≥2 mmol/L时,预测患者死亡率的敏感度为83.33%(30/36)、特异度为78.30%(83/106)、准确性为79.58%(113/142)、阳性预测值为56.60%(30/53)、阴性预测值93.26%(83/89);当乳酸清除率≥10%时,预测患者死亡率的敏感度为86.11%(31/36)、特异度为80.19%(85/106)、准确性为81.69%(116/142)、阳性预测值为59.62%(31/52)、阴性预测值94.44%(85/90)。结论:失血性低血容量休克患者早期动脉血乳酸水平越高,乳酸清除率越低,患者预后越差,且动脉血乳酸水平及乳酸清除率可有效地评估患者病情严重程度及预后情况,均具有重要评估价值。展开更多
文摘Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.
文摘目的:分析早期动脉血乳酸水平及乳酸清除率对失血性低血容量休克患者预后的评估价值。方法:选取本院2015年5月-2016年6月重症监护病房(ICU)收治的失血性低血容量休克患者142例作为研究对象,根据疾病转归,将患者分为存活组和死亡组,其中存活组106例,死亡组36例。比较两组患者年龄、性别比例,并采用急性生理学和慢性健康评分(Acute Physiology and Chronic Health Evaluation,APACHEⅡ)评估患者的病情严重性,分别检测患者入院时及入院治疗6 h早期动脉血乳酸水平,计算患者6 h乳酸清除率,采用ROC曲线评估早期动脉血乳酸水平及乳酸清除率对患者的预后价值。结果:两组APACHEⅡ评分比较差异无统计学意义(P>0.05);存活组入院时及入院治疗6 h的动脉血乳酸浓度均低于死亡组,且存活组的乳酸清除率明显高于死亡组,比较差异均有统计学意义(P<0.05);ROC曲线分析结果显示,早期动脉血乳酸水平及乳酸清除率对失血性低血容量休克患者预后评估价值良好,当血液乳酸浓度≥2 mmol/L时,预测患者死亡率的敏感度为83.33%(30/36)、特异度为78.30%(83/106)、准确性为79.58%(113/142)、阳性预测值为56.60%(30/53)、阴性预测值93.26%(83/89);当乳酸清除率≥10%时,预测患者死亡率的敏感度为86.11%(31/36)、特异度为80.19%(85/106)、准确性为81.69%(116/142)、阳性预测值为59.62%(31/52)、阴性预测值94.44%(85/90)。结论:失血性低血容量休克患者早期动脉血乳酸水平越高,乳酸清除率越低,患者预后越差,且动脉血乳酸水平及乳酸清除率可有效地评估患者病情严重程度及预后情况,均具有重要评估价值。
