The resolution characteristic of GaAs/GaAlAs transmission photocathode is an important parameter in third generation intensifiers. The modulation transfer function of GaAs/GaAlAs transmission photo...The resolution characteristic of GaAs/GaAlAs transmission photocathode is an important parameter in third generation intensifiers. The modulation transfer function of GaAs/GaAlAs transmission photocathode is derived from a simple two-dimensional diffusion equation. The theoretical resolution characteristic of a 2 μm thick GaAs/GaAlAs transmission photocathode is calculated. The relationship between resolution and parameters in GaAs/GaAlAs transmission photocathode is discussed. A conclusion is shown that one can design the GaAs/GaAlAs transmission photocathode for maximum quantum efficiency, since the sacrifice in the resolution doesn't limit system performances.展开更多
An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in e...An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.展开更多
Credit scoring models are quantitative models used commonly by financial institutions in the measurement and forecasting of credit risk, having a consolidated use in the process of credit concession of these instituti...Credit scoring models are quantitative models used commonly by financial institutions in the measurement and forecasting of credit risk, having a consolidated use in the process of credit concession of these institutions. The purpose of this paper was to evaluate the possibility of application of credit scoring models in a microcredit institution named Fundo Rotativo de A~~o da Cidadania--Cred Cidadania （Revolving Fund of Citizenship Action--Cred Cidadania）, located in Recife （Brazil）. In order to do this, data related to a sample of clients of the Cred Cidadania was collected, and this data was used to develop two types of credit scoring models： one is credit approval, another is called behavioral scoring. The statistical technique applied in the construction of the models was logistic regression. The results of the study demonstrated that the credit scoring models obtain satisfactory performance when used in the analysis of credit risk in the Cred Cidadania microcredit institution, reaching a correct client classification percentile of about 80%. The results also indicate that the use of credit scoring models supplies subsidies to the institution, aiding it in the prevention and reduction of insolvency and in the decrease of its operational costs, two problems that affect their financial sustainability.展开更多
A single on/off valve is used to carry out the position control of the asymmetrical hydraulic cylinder. The influence of the nominal flow rate on the positional accuracy of piston is investigated and the proximate for...A single on/off valve is used to carry out the position control of the asymmetrical hydraulic cylinder. The influence of the nominal flow rate on the positional accuracy of piston is investigated and the proximate formula for calculating the nominal flow rate of on/off valve is introduced. The system structure proposed in this paper could avoid cavitation and hyper pressure in two chambers to some extent. The simulation results indicated that the control method in this paper could satisfy the expected control requirements.展开更多
文摘The resolution characteristic of GaAs/GaAlAs transmission photocathode is an important parameter in third generation intensifiers. The modulation transfer function of GaAs/GaAlAs transmission photocathode is derived from a simple two-dimensional diffusion equation. The theoretical resolution characteristic of a 2 μm thick GaAs/GaAlAs transmission photocathode is calculated. The relationship between resolution and parameters in GaAs/GaAlAs transmission photocathode is discussed. A conclusion is shown that one can design the GaAs/GaAlAs transmission photocathode for maximum quantum efficiency, since the sacrifice in the resolution doesn't limit system performances.
基金Project(21075138)supported by the National Natural Science Foundation of ChinaProject(cstc2013jcyjA10088)supported by Chongqing Natural Science Foundation,ChinaProject(KJ121311)supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission,China
文摘An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.
文摘Credit scoring models are quantitative models used commonly by financial institutions in the measurement and forecasting of credit risk, having a consolidated use in the process of credit concession of these institutions. The purpose of this paper was to evaluate the possibility of application of credit scoring models in a microcredit institution named Fundo Rotativo de A~~o da Cidadania--Cred Cidadania （Revolving Fund of Citizenship Action--Cred Cidadania）, located in Recife （Brazil）. In order to do this, data related to a sample of clients of the Cred Cidadania was collected, and this data was used to develop two types of credit scoring models： one is credit approval, another is called behavioral scoring. The statistical technique applied in the construction of the models was logistic regression. The results of the study demonstrated that the credit scoring models obtain satisfactory performance when used in the analysis of credit risk in the Cred Cidadania microcredit institution, reaching a correct client classification percentile of about 80%. The results also indicate that the use of credit scoring models supplies subsidies to the institution, aiding it in the prevention and reduction of insolvency and in the decrease of its operational costs, two problems that affect their financial sustainability.
基金the National Natural Science Foundation of China (No. 50575202)
文摘A single on/off valve is used to carry out the position control of the asymmetrical hydraulic cylinder. The influence of the nominal flow rate on the positional accuracy of piston is investigated and the proximate formula for calculating the nominal flow rate of on/off valve is introduced. The system structure proposed in this paper could avoid cavitation and hyper pressure in two chambers to some extent. The simulation results indicated that the control method in this paper could satisfy the expected control requirements.
