在1 k Hz^100 MHz范围内,采用Agilent 4294A精密阻抗分析仪,测量人肺鳞癌SK-MES-1细胞悬浮液的电阻抗,通过电阻抗频谱图和Nyquist图的分析,提取肺癌细胞电阻抗频谱的特征参数,并与人正常肺上皮BEAS-2B细胞进行比较。结果显示:肺癌细胞...在1 k Hz^100 MHz范围内,采用Agilent 4294A精密阻抗分析仪,测量人肺鳞癌SK-MES-1细胞悬浮液的电阻抗,通过电阻抗频谱图和Nyquist图的分析,提取肺癌细胞电阻抗频谱的特征参数,并与人正常肺上皮BEAS-2B细胞进行比较。结果显示:肺癌细胞与正常人肺细胞悬浮液的电阻抗谱存在着较显著的差异;肺鳞癌细胞的电阻抗实部增量最大值(ΔZmax)和电阻抗虚部峰值(Z″P)与细胞体积分数(Φ)呈线性关系;肺鳞癌细胞悬浮液阻抗谱的特征频率(fc)低于正常人肺细胞的54.72%(P<0.001),并且不受细胞体积分数的影响。这表明,细胞悬浮液阻抗谱特征频率可以用于区分肺鳞癌细胞和正常人肺细胞,可为肺鳞癌细胞的鉴定与分型提供电生理指标。展开更多
For this study,we synthesized Aurivillius Bi_(5)Ti_(3)FeO_(15) ceramic using the generic solid-state reaction route and then performed roomtemperature X-ray diffraction to confirm that the compound had a single phase ...For this study,we synthesized Aurivillius Bi_(5)Ti_(3)FeO_(15) ceramic using the generic solid-state reaction route and then performed roomtemperature X-ray diffraction to confirm that the compound had a single phase with no impurities.The surface morphology of the prepared sample was observed to contain microstructural grains approximately 0.2–2μm in size.The dielectric properties of the sample were determined as a function of frequency in a range of approximately 100 Hz to 1 MHz at various temperatures(303 K≤T≤773 K).Nyquist plots of the impedance data were found to exhibit a semi-circular arc in the high-temperature region,which is explained by the equivalent electrical circuit(R_(1)C_(1))(R_(2)QC_(2)),where R_(1) and R_(2) represent the resistances associated with the grains and grain boundaries,respectively,C_(1) and C_(2) are the respective capacitances,and Q is the constant phase element(CPE),which accounts for non-Debye type of behavior.Our results indicate that both the resistance and capacitance of the grain boundaries are more prominent than those of the grains.The alternating current(ac)conductivity data were analyzed based on the Jonscher universal power law,which indicated that the conduction process is dominated by the hopping mechanism.The calculated activation energies of the relaxation and conduction processes were very similar(0.32 to 0.53 eV),from which we conclude that the same type of charge carriers are involved in both processes.展开更多
In this paper, the stabilization of neutral time-delay systems is investigated. An efficient numerical approach is presented in an algorithm to establish results so that stability of such systems is achieved and stabi...In this paper, the stabilization of neutral time-delay systems is investigated. An efficient numerical approach is presented in an algorithm to establish results so that stability of such systems is achieved and stabilizing PID parameters are determined directly. It is based on determining the rightmost characteristic roots and Nyquist plot. The Newton-Raphson’s iterative method based on Lambert W function is used for the calculation of these stabilizing roots directly from the closed-loop characteristic equation of the neutral time-delay system and then stability is checked by Nyquist plot and step response of closed-loop system. Two numerical examples are included to illustrate the effectiveness of the proposed approach.展开更多
We report a facile, two-step hydrothermal synthesis of a novel Co304/a-Fe2O3 branched nanowire heterostructure, which can serve as a good candidate for lithium-ion battery anodes with high Li＋ storage capacity and st...We report a facile, two-step hydrothermal synthesis of a novel Co304/a-Fe2O3 branched nanowire heterostructure, which can serve as a good candidate for lithium-ion battery anodes with high Li＋ storage capacity and stability. The single-crystalline, primary C0304 nanowire trunk arrays directly grown on Ti substrates allow for efficient electrical and ionic transport. The secondary a-Fe2O3 branches provide enhanced surface area and high theoretical Li＋ storage capacity, and can also serve as volume spacers between neighboring Co3O4 NW arrays to maintain electrolyte penetration as well as reduce the aggregation during Li＋ intercalation, thus leading to improved electrochemical energy storage performance.展开更多
文摘在1 k Hz^100 MHz范围内,采用Agilent 4294A精密阻抗分析仪,测量人肺鳞癌SK-MES-1细胞悬浮液的电阻抗,通过电阻抗频谱图和Nyquist图的分析,提取肺癌细胞电阻抗频谱的特征参数,并与人正常肺上皮BEAS-2B细胞进行比较。结果显示:肺癌细胞与正常人肺细胞悬浮液的电阻抗谱存在着较显著的差异;肺鳞癌细胞的电阻抗实部增量最大值(ΔZmax)和电阻抗虚部峰值(Z″P)与细胞体积分数(Φ)呈线性关系;肺鳞癌细胞悬浮液阻抗谱的特征频率(fc)低于正常人肺细胞的54.72%(P<0.001),并且不受细胞体积分数的影响。这表明,细胞悬浮液阻抗谱特征频率可以用于区分肺鳞癌细胞和正常人肺细胞,可为肺鳞癌细胞的鉴定与分型提供电生理指标。
基金Anil Kumar Singh acknowledges the Board of Research in Nuclear Science(BRNS)Mumbai(Sanction No.2012/37P/40/BRNS/2145)+1 种基金the UGC-DAE Consortium for Scientific Research,Mumbai(Sanction No.CRS-M-187,225)the Science and Engineering Research Board(SERB),New Delhi(Sanction No.SR/FTS/PS-187/2011)for funding.
文摘For this study,we synthesized Aurivillius Bi_(5)Ti_(3)FeO_(15) ceramic using the generic solid-state reaction route and then performed roomtemperature X-ray diffraction to confirm that the compound had a single phase with no impurities.The surface morphology of the prepared sample was observed to contain microstructural grains approximately 0.2–2μm in size.The dielectric properties of the sample were determined as a function of frequency in a range of approximately 100 Hz to 1 MHz at various temperatures(303 K≤T≤773 K).Nyquist plots of the impedance data were found to exhibit a semi-circular arc in the high-temperature region,which is explained by the equivalent electrical circuit(R_(1)C_(1))(R_(2)QC_(2)),where R_(1) and R_(2) represent the resistances associated with the grains and grain boundaries,respectively,C_(1) and C_(2) are the respective capacitances,and Q is the constant phase element(CPE),which accounts for non-Debye type of behavior.Our results indicate that both the resistance and capacitance of the grain boundaries are more prominent than those of the grains.The alternating current(ac)conductivity data were analyzed based on the Jonscher universal power law,which indicated that the conduction process is dominated by the hopping mechanism.The calculated activation energies of the relaxation and conduction processes were very similar(0.32 to 0.53 eV),from which we conclude that the same type of charge carriers are involved in both processes.
文摘In this paper, the stabilization of neutral time-delay systems is investigated. An efficient numerical approach is presented in an algorithm to establish results so that stability of such systems is achieved and stabilizing PID parameters are determined directly. It is based on determining the rightmost characteristic roots and Nyquist plot. The Newton-Raphson’s iterative method based on Lambert W function is used for the calculation of these stabilizing roots directly from the closed-loop characteristic equation of the neutral time-delay system and then stability is checked by Nyquist plot and step response of closed-loop system. Two numerical examples are included to illustrate the effectiveness of the proposed approach.
文摘We report a facile, two-step hydrothermal synthesis of a novel Co304/a-Fe2O3 branched nanowire heterostructure, which can serve as a good candidate for lithium-ion battery anodes with high Li＋ storage capacity and stability. The single-crystalline, primary C0304 nanowire trunk arrays directly grown on Ti substrates allow for efficient electrical and ionic transport. The secondary a-Fe2O3 branches provide enhanced surface area and high theoretical Li＋ storage capacity, and can also serve as volume spacers between neighboring Co3O4 NW arrays to maintain electrolyte penetration as well as reduce the aggregation during Li＋ intercalation, thus leading to improved electrochemical energy storage performance.
