We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1...We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.展开更多
In fitting the double-differential measurements thelevelwidth broadening effect should be taken into account properly due to Heisenberg uncertainty.Besides level width broadening effect the energy resolution in the me...In fitting the double-differential measurements thelevelwidth broadening effect should be taken into account properly due to Heisenberg uncertainty.Besides level width broadening effect the energy resolution in the measurements is also needed in this procedure.In general,the traditional normal Gaussian expansion is employed.However,the research indicates that to do so in this way the energy balance could not hold.For this reason,the deformed Gaussian expansion functions with exponential form for both the single energy point and continuous spectrum are introduced,with which the normalization and energy balance conditions could hold exactly in the analytical form.展开更多
In the paper,we study the strong uniform consistency for the kernal estimates of random window w■th of density function and its derivatives under the condition that the sequence{X_n}of the ■ are the identically Φ-m...In the paper,we study the strong uniform consistency for the kernal estimates of random window w■th of density function and its derivatives under the condition that the sequence{X_n}of the ■ are the identically Φ-mixing random variabks.展开更多
Recently, Islamic banks have been presented as an alternative to conventional banks. Indeed, Islamic banks have proved their worth during the 2009 crisis. They are known like an ethical bank. In Tunisia, only three Is...Recently, Islamic banks have been presented as an alternative to conventional banks. Indeed, Islamic banks have proved their worth during the 2009 crisis. They are known like an ethical bank. In Tunisia, only three Islamic banks exist. Even the conventional banks are interested to offer Islamic banking products and services; they are called Islamic banking window. This paper aims to determine the level of acceptance of Islamic banking window on Tunisian consumers and the impact of the social professional category on it. The research questions as follows： Are the consumers familiar with the financial Islamic products？ Did they perceive any differences between conventional and Islamic financial products？ What are the levels of acceptance of an Islamic banking product offered by a conventional bank？ In this respect, a questionnaire was administrated to a sample size of 120 people constituted of 54% men and 46% women from Tunis City. Three types of social professional category are found： 62% employee, 32% senior, and 6% profession. The data were processed by SPSS 21. The results showed that the majority of the respondents have a lack of knowledge of the Islamic banking products. The majority of the respondents don＇t see any differences between the product name of conventional and Islamic banking products. The acceptance level of an Islamic banking product offered by a conventional bank is very satisfying, 53% of the respondents are certain to purchase an Islamic banking product from a conventional bank and 42% are not sure. Only 5% refused.展开更多
This work presents an implementation of an innovative single phase multilevel inverter using capacitors with reduced switches. The proposed Capacitor pattern H-bridge Multilevel Inverter (CPHMLI) topology consists of ...This work presents an implementation of an innovative single phase multilevel inverter using capacitors with reduced switches. The proposed Capacitor pattern H-bridge Multilevel Inverter (CPHMLI) topology consists of a proper number of Capacitor connected with switches and power sources. The advanced switching control supplied by Pulse Width Modulation (PDPWM) to attain mixed staircase switching state. The charging and discharging mode are achieved by calculating the voltage error at the load. Furthermore, to accomplish the higher voltage levels at the output with less number of semiconductors switches and simple commutation designed using CPHMLI topology. To prove the performance and effectiveness of the proposed approach, a set of experiments performed under various load conditions using MATLAB tool.展开更多
按照网络安全法等法律法规要求,应依法实施网络安全等级保护制度,深化网络安全等级保护政策和标准落实,健全完善网络安全保护工作机制,确保网络安全等级保护等级测评工作有效开展。文章分析了Windows服务器面临的安全问题及原因,按照等...按照网络安全法等法律法规要求,应依法实施网络安全等级保护制度,深化网络安全等级保护政策和标准落实,健全完善网络安全保护工作机制,确保网络安全等级保护等级测评工作有效开展。文章分析了Windows服务器面临的安全问题及原因,按照等级保护计算环境服务器(三级)相关测评项要求,以Windows Server 2019为研究对象,结合等级测评工作实践提出了Windows服务器安全加固方法,能帮助单位完成操作系统等级保护测评工作,提升操作系统层安全防护能力。展开更多
在三相两电平逆变器中,虚拟空间矢量调制(virtual space vector modulation,VSVM)因其能降低共模电压的幅值和三次谐波而受到广泛关注,但还存在共模电压的谐波成分丰富,且幅值变化和方向变化的发生率较高的问题,为此提出一种改进型VSVM...在三相两电平逆变器中,虚拟空间矢量调制(virtual space vector modulation,VSVM)因其能降低共模电压的幅值和三次谐波而受到广泛关注,但还存在共模电压的谐波成分丰富,且幅值变化和方向变化的发生率较高的问题,为此提出一种改进型VSVM方法。该方法通过分析经典VSVM的矢量合成和共模电压特点,对虚拟矢量和虚拟零矢量所对应的基本矢量进行优化排序,使每个开关周期的共模电压波形相同,均为单个矩形波。进一步分析了所提方法的共模谐波、死区补偿和开关损耗。在逆变器-永磁同步电机系统中进行仿真和实验。结果表明:与经典VSVM相比,所提方法在保持共模电压低幅值的同时,使幅值变化和方向变化的发生率都降低3倍,完全消除基带谐波和边带谐波分量,并使共模电压的高频段峰值平均减小6 dB,且线电流、线电压、转矩和转速等性能依然良好。该方法在不增加系统体积和成本的情况下,能更有效抑制共模干扰,有利于共模滤波器的设计,并为其他共模抑制脉冲宽度调制(pulse width modulation,PWM)方法的研究提供了借鉴。展开更多
针对多电平移相全数字发信机(All Digital Transmitter,ADTx)架构中脉冲波形幅度不平衡误差问题,开展了误差机理分析和数值仿真研究。提出了一个基于ADTx硬件电路不理想性引起的脉冲幅度不平衡误差非线性失真模型,并推导分析了脉冲幅度...针对多电平移相全数字发信机(All Digital Transmitter,ADTx)架构中脉冲波形幅度不平衡误差问题,开展了误差机理分析和数值仿真研究。提出了一个基于ADTx硬件电路不理想性引起的脉冲幅度不平衡误差非线性失真模型,并推导分析了脉冲幅度不平衡误差对输出信号时域波形的畸变机制。通过数值仿真研究了脉冲幅度不平衡误差对发信机线性性能的影响。实验结果表明,脉冲幅度不平衡误差会显著恶化误差矢量幅度(Error Vector Magnitude,EVM)、邻信道功率比(Adjacent Channel Power Ratio,ACPR)以及三次谐波抑制性能等关键性能指标。深入分析该幅度不平衡误差对于准确评估并消除误差、提升多电平ADTx系统性能具有重要的理论和实践意义。展开更多
文摘We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.
文摘In fitting the double-differential measurements thelevelwidth broadening effect should be taken into account properly due to Heisenberg uncertainty.Besides level width broadening effect the energy resolution in the measurements is also needed in this procedure.In general,the traditional normal Gaussian expansion is employed.However,the research indicates that to do so in this way the energy balance could not hold.For this reason,the deformed Gaussian expansion functions with exponential form for both the single energy point and continuous spectrum are introduced,with which the normalization and energy balance conditions could hold exactly in the analytical form.
基金supported by Natural Science Foun■ion of Henan P■visial Commission of Bdusation
文摘In the paper,we study the strong uniform consistency for the kernal estimates of random window w■th of density function and its derivatives under the condition that the sequence{X_n}of the ■ are the identically Φ-mixing random variabks.
文摘Recently, Islamic banks have been presented as an alternative to conventional banks. Indeed, Islamic banks have proved their worth during the 2009 crisis. They are known like an ethical bank. In Tunisia, only three Islamic banks exist. Even the conventional banks are interested to offer Islamic banking products and services; they are called Islamic banking window. This paper aims to determine the level of acceptance of Islamic banking window on Tunisian consumers and the impact of the social professional category on it. The research questions as follows： Are the consumers familiar with the financial Islamic products？ Did they perceive any differences between conventional and Islamic financial products？ What are the levels of acceptance of an Islamic banking product offered by a conventional bank？ In this respect, a questionnaire was administrated to a sample size of 120 people constituted of 54% men and 46% women from Tunis City. Three types of social professional category are found： 62% employee, 32% senior, and 6% profession. The data were processed by SPSS 21. The results showed that the majority of the respondents have a lack of knowledge of the Islamic banking products. The majority of the respondents don＇t see any differences between the product name of conventional and Islamic banking products. The acceptance level of an Islamic banking product offered by a conventional bank is very satisfying, 53% of the respondents are certain to purchase an Islamic banking product from a conventional bank and 42% are not sure. Only 5% refused.
文摘This work presents an implementation of an innovative single phase multilevel inverter using capacitors with reduced switches. The proposed Capacitor pattern H-bridge Multilevel Inverter (CPHMLI) topology consists of a proper number of Capacitor connected with switches and power sources. The advanced switching control supplied by Pulse Width Modulation (PDPWM) to attain mixed staircase switching state. The charging and discharging mode are achieved by calculating the voltage error at the load. Furthermore, to accomplish the higher voltage levels at the output with less number of semiconductors switches and simple commutation designed using CPHMLI topology. To prove the performance and effectiveness of the proposed approach, a set of experiments performed under various load conditions using MATLAB tool.
文摘按照网络安全法等法律法规要求,应依法实施网络安全等级保护制度,深化网络安全等级保护政策和标准落实,健全完善网络安全保护工作机制,确保网络安全等级保护等级测评工作有效开展。文章分析了Windows服务器面临的安全问题及原因,按照等级保护计算环境服务器(三级)相关测评项要求,以Windows Server 2019为研究对象,结合等级测评工作实践提出了Windows服务器安全加固方法,能帮助单位完成操作系统等级保护测评工作,提升操作系统层安全防护能力。
文摘针对多电平移相全数字发信机(All Digital Transmitter,ADTx)架构中脉冲波形幅度不平衡误差问题,开展了误差机理分析和数值仿真研究。提出了一个基于ADTx硬件电路不理想性引起的脉冲幅度不平衡误差非线性失真模型,并推导分析了脉冲幅度不平衡误差对输出信号时域波形的畸变机制。通过数值仿真研究了脉冲幅度不平衡误差对发信机线性性能的影响。实验结果表明,脉冲幅度不平衡误差会显著恶化误差矢量幅度(Error Vector Magnitude,EVM)、邻信道功率比(Adjacent Channel Power Ratio,ACPR)以及三次谐波抑制性能等关键性能指标。深入分析该幅度不平衡误差对于准确评估并消除误差、提升多电平ADTx系统性能具有重要的理论和实践意义。
