The solar photovoltaic (PV) market has grown very rapidly throughout the past 15 years and is quickly becoming an international, non-subsidized market with increased demand for performance certainty. An increasing num...The solar photovoltaic (PV) market has grown very rapidly throughout the past 15 years and is quickly becoming an international, non-subsidized market with increased demand for performance certainty. An increasing number of studies analyze long-term monitoring data to determine degradation rates, or “rates of change” (RoCs). Analyses of long-term monitoring data give insight in the performance of PV power plants over time, but are found to be sensitive to uncertainties, especially those related to irradiance measurements using silicon reference cells. The case study analysis shows, however, that the RoCs are much lower if reference cells are adjusted for soiling, drifting and sensor replacements or if satellite irradiance data is used. This indicates that the impact of biased irradiance data should not be underestimated. It was also found, that the distribution of RoCs is strongly influenced by the age and size of the selected systems, underlining the importance of system selection. The case study analysis indicates that crystalline silicon PV systems operating for 8+ years are expected to show a “rate of change” of -0.5% per year or fewer. In this paper the 15-minute data has been collected from a solar photovoltaic generating station installed on the roof of engineering college building and efficiency/degradation of solar panels have been analyzed and reported.展开更多
目的探讨降钙素原变化率在重症肺炎中的诊断价值。方法收集2016年1月-2018年1月医院呼吸内科的重症肺炎患者123例临床资料,根据患者降钙素原变化率[(入院24h时-入院时)降钙素原/入院时降钙素原],将患者分为试验组(降钙素原变化率≤-10%...目的探讨降钙素原变化率在重症肺炎中的诊断价值。方法收集2016年1月-2018年1月医院呼吸内科的重症肺炎患者123例临床资料,根据患者降钙素原变化率[(入院24h时-入院时)降钙素原/入院时降钙素原],将患者分为试验组(降钙素原变化率≤-10%)和对照组(降钙素原变化率>-10%)。比较两组患者的主要临床特征,包括入院时白细胞、中性粒细胞、急性生理与慢性健康评分(Acute Physiology and Chronic Health Evaluation,APACHEⅡ评分)、呼吸机使用率、呼吸机使用时间、抗菌素使用时间、住院时间、脓毒血症、休克、多器官功能衰竭和死亡的发生率,同时使用ROC曲线分析降钙素原在诊断重症肺炎患者死亡中的价值。结果与对照组比较,试验组患者白细胞、中性粒细胞、APACHEⅡ评分、呼吸机使用率、呼吸机使用时间、抗菌素使用时间、住院时间、脓毒症、休克、多器官功能衰竭、死亡率等均降低(P<0.05);降钙素原变化率对诊断重症肺炎患者死亡结局的ROC曲线分析结果显示0.882(95%CI 0.818～0.946),其诊断价值高于降钙素原、APACHEⅡ评分、白细胞和中性粒细胞。结论降钙素原变化率与重症肺炎患者临床治疗和转归密切相关,计算方法简单,可用于指导临床治疗和诊断。展开更多
Technology of passive location has broad prospects in applications. In this paper, the method using the phase rate of change for the single observer passive location is introduced based on existing methods. One can ob...Technology of passive location has broad prospects in applications. In this paper, the method using the phase rate of change for the single observer passive location is introduced based on existing methods. One can obtain the direction of the target with phase information of two orthogonal interferometers on the observer and the radial distance with the corresponding phase rate of change. Then the target can be located with high speed and precision. A locating approach is given when the flying posture of t...展开更多
文摘The solar photovoltaic (PV) market has grown very rapidly throughout the past 15 years and is quickly becoming an international, non-subsidized market with increased demand for performance certainty. An increasing number of studies analyze long-term monitoring data to determine degradation rates, or “rates of change” (RoCs). Analyses of long-term monitoring data give insight in the performance of PV power plants over time, but are found to be sensitive to uncertainties, especially those related to irradiance measurements using silicon reference cells. The case study analysis shows, however, that the RoCs are much lower if reference cells are adjusted for soiling, drifting and sensor replacements or if satellite irradiance data is used. This indicates that the impact of biased irradiance data should not be underestimated. It was also found, that the distribution of RoCs is strongly influenced by the age and size of the selected systems, underlining the importance of system selection. The case study analysis indicates that crystalline silicon PV systems operating for 8+ years are expected to show a “rate of change” of -0.5% per year or fewer. In this paper the 15-minute data has been collected from a solar photovoltaic generating station installed on the roof of engineering college building and efficiency/degradation of solar panels have been analyzed and reported.
文摘目的探讨降钙素原变化率在重症肺炎中的诊断价值。方法收集2016年1月-2018年1月医院呼吸内科的重症肺炎患者123例临床资料,根据患者降钙素原变化率[(入院24h时-入院时)降钙素原/入院时降钙素原],将患者分为试验组(降钙素原变化率≤-10%)和对照组(降钙素原变化率>-10%)。比较两组患者的主要临床特征,包括入院时白细胞、中性粒细胞、急性生理与慢性健康评分(Acute Physiology and Chronic Health Evaluation,APACHEⅡ评分)、呼吸机使用率、呼吸机使用时间、抗菌素使用时间、住院时间、脓毒血症、休克、多器官功能衰竭和死亡的发生率,同时使用ROC曲线分析降钙素原在诊断重症肺炎患者死亡中的价值。结果与对照组比较,试验组患者白细胞、中性粒细胞、APACHEⅡ评分、呼吸机使用率、呼吸机使用时间、抗菌素使用时间、住院时间、脓毒症、休克、多器官功能衰竭、死亡率等均降低(P<0.05);降钙素原变化率对诊断重症肺炎患者死亡结局的ROC曲线分析结果显示0.882(95%CI 0.818～0.946),其诊断价值高于降钙素原、APACHEⅡ评分、白细胞和中性粒细胞。结论降钙素原变化率与重症肺炎患者临床治疗和转归密切相关,计算方法简单,可用于指导临床治疗和诊断。
文摘Technology of passive location has broad prospects in applications. In this paper, the method using the phase rate of change for the single observer passive location is introduced based on existing methods. One can obtain the direction of the target with phase information of two orthogonal interferometers on the observer and the radial distance with the corresponding phase rate of change. Then the target can be located with high speed and precision. A locating approach is given when the flying posture of t...
