A model that rapidly predicts the density components of raw coal is described.It is based on a threegrade fast float/sink test.The recent comprehensive monthly floating and sinking data are used for comparison.The pre...A model that rapidly predicts the density components of raw coal is described.It is based on a threegrade fast float/sink test.The recent comprehensive monthly floating and sinking data are used for comparison.The predicted data are used to draw washability curves and to provide a rapid evaluation of the effect from heavy medium induced separation.Thirty-one production shifts worth of fast float/sink data and the corresponding quick ash data are used to verify the model.The results show a small error with an arithmetic average of 0.53 and an absolute average error of 1.50.This indicates that this model has high precision.The theoretical yield from the washability curves is 76.47% for the monthly comprehensive data and 81.31% using the model data.This is for a desired cleaned coal ash of 9%.The relative error between these two is 6.33%,which is small and indicates that the predicted data can be used to rapidly evaluate the separation effect of gravity separation equipment.展开更多
着重介绍受试者工作特征(Receiver Operating Characteristic,ROC)曲线的理论,以及在诊断试验准确性评价中的应用。通过对五种乙型肝炎病毒表面抗原诊断试剂评价的实例,简要说明ROC曲线下面积(Area Under Curve,AUC)、部分ROCAUC和固定...着重介绍受试者工作特征(Receiver Operating Characteristic,ROC)曲线的理论,以及在诊断试验准确性评价中的应用。通过对五种乙型肝炎病毒表面抗原诊断试剂评价的实例,简要说明ROC曲线下面积(Area Under Curve,AUC)、部分ROCAUC和固定特异度时灵敏度的计算方法及其意义,以及这些指标相互比较的Bootstrap方法。展开更多
Aquatic and semi-aquatic mammals, while resting at the water surface or ashore, breathe with a low frequency （f） by comparison to terrestrial mammals of the same body size, the difference increasing the larger the s...Aquatic and semi-aquatic mammals, while resting at the water surface or ashore, breathe with a low frequency （f） by comparison to terrestrial mammals of the same body size, the difference increasing the larger the species. Among various interpretations, it was suggested that the low-f breathing is a consequence of the end-inspiratory breath-holding pattern adopted by aquatic mammals to favour buoyancy at the water surface, and evolved to be part of the genetic makeup. If this interpretation was correct it could be expected that, differently from f, the heart rate （HR, beats/min） of aquatic and semi-aquatic mammals at rest would not need to differ from that of terrestrial mammals and that their HR-fratio would be higher than in terrestrial species. Literature data for HR （beats/min） in mammals at rest were gathered for 56 terrestrial and 27 aquatic species. In aquatic mammals the allometric curve （HR=191 .M^18; M= body mass, kg） did not differ from that of terrestrial species （HR=212.M^-0.22） and their HR-fratio （on average 32±5） was much higher than in terrestrial species （5±1） （P〈0.0001）. The comparison of these HR allometric curves to those forfpreviously published indicated that the HR-fratio was body size-independent in terrestrial species while it increased significantly with M in aquatic species. The similarity in HR and differences in f between aquatic and terrestrial mammals agree with the possibility that the lowfof aquatic and semi-aquatic mammals may have evolved for a non-respiratory function, namely the regulation of buoyancy at the water surface [Current Zoology 61（4）： 569-577, 2015].展开更多
The authors prove some global existence results for equations of Kirchhoff type, i.e., nonlinearstretched string with nonlocal terms, depending on a parameter. This general setting includes the known results on the Ki...The authors prove some global existence results for equations of Kirchhoff type, i.e., nonlinearstretched string with nonlocal terms, depending on a parameter. This general setting includes the known results on the Kirchhoff equation with small data. Moreover, the authors can also handle some cases of degeneracy, which escaped earlier methods.展开更多
基金National Natural Science Foundation of China (No. 51174202)Doctoral Fund of Ministry of Education of China (No. 20100095110013)
文摘A model that rapidly predicts the density components of raw coal is described.It is based on a threegrade fast float/sink test.The recent comprehensive monthly floating and sinking data are used for comparison.The predicted data are used to draw washability curves and to provide a rapid evaluation of the effect from heavy medium induced separation.Thirty-one production shifts worth of fast float/sink data and the corresponding quick ash data are used to verify the model.The results show a small error with an arithmetic average of 0.53 and an absolute average error of 1.50.This indicates that this model has high precision.The theoretical yield from the washability curves is 76.47% for the monthly comprehensive data and 81.31% using the model data.This is for a desired cleaned coal ash of 9%.The relative error between these two is 6.33%,which is small and indicates that the predicted data can be used to rapidly evaluate the separation effect of gravity separation equipment.
文摘着重介绍受试者工作特征(Receiver Operating Characteristic,ROC)曲线的理论,以及在诊断试验准确性评价中的应用。通过对五种乙型肝炎病毒表面抗原诊断试剂评价的实例,简要说明ROC曲线下面积(Area Under Curve,AUC)、部分ROCAUC和固定特异度时灵敏度的计算方法及其意义,以及这些指标相互比较的Bootstrap方法。
文摘Aquatic and semi-aquatic mammals, while resting at the water surface or ashore, breathe with a low frequency （f） by comparison to terrestrial mammals of the same body size, the difference increasing the larger the species. Among various interpretations, it was suggested that the low-f breathing is a consequence of the end-inspiratory breath-holding pattern adopted by aquatic mammals to favour buoyancy at the water surface, and evolved to be part of the genetic makeup. If this interpretation was correct it could be expected that, differently from f, the heart rate （HR, beats/min） of aquatic and semi-aquatic mammals at rest would not need to differ from that of terrestrial mammals and that their HR-fratio would be higher than in terrestrial species. Literature data for HR （beats/min） in mammals at rest were gathered for 56 terrestrial and 27 aquatic species. In aquatic mammals the allometric curve （HR=191 .M^18; M= body mass, kg） did not differ from that of terrestrial species （HR=212.M^-0.22） and their HR-fratio （on average 32±5） was much higher than in terrestrial species （5±1） （P〈0.0001）. The comparison of these HR allometric curves to those forfpreviously published indicated that the HR-fratio was body size-independent in terrestrial species while it increased significantly with M in aquatic species. The similarity in HR and differences in f between aquatic and terrestrial mammals agree with the possibility that the lowfof aquatic and semi-aquatic mammals may have evolved for a non-respiratory function, namely the regulation of buoyancy at the water surface [Current Zoology 61（4）： 569-577, 2015].
文摘The authors prove some global existence results for equations of Kirchhoff type, i.e., nonlinearstretched string with nonlocal terms, depending on a parameter. This general setting includes the known results on the Kirchhoff equation with small data. Moreover, the authors can also handle some cases of degeneracy, which escaped earlier methods.
