A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.T...A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.This proposed implementation relies on the tunability of current-steering MOS transistors operating in the triode region counteracting the concert deviation of resistor in the integrated circuit manufacturing technology in orde r that the group delay of Bessel active filter could be designed accurately.The amplifier is not only with voltage common-mode negative feedback,but also with current common-mode negative feedback,which will benefit for the stability of its D C operating point.0.75μs group delay fourth-order Bessel lowpass filter,whic h is synthesized according to passive doubly terminated RLC prototype lowpass filter,demonstrates better than -65dB THD using 100kHz,2.5V pp signal in Taiwan UMC 2P2M(2-poly,2-metal)5.0V,0.5μm CMOS technology.展开更多
目的:采用高效液相色谱法测定化合物ent-kaur-16-en-19-oic ac id在光叶番荔枝不同部位和番荔枝属不同种类植物叶子中的含量。方法:色谱条件为:Nuc leosil C18色谱柱,流动相选用乙睛:水(含1%冰醋酸)=67.5:32.5,检测波长211nm。结果:平...目的:采用高效液相色谱法测定化合物ent-kaur-16-en-19-oic ac id在光叶番荔枝不同部位和番荔枝属不同种类植物叶子中的含量。方法:色谱条件为:Nuc leosil C18色谱柱,流动相选用乙睛:水(含1%冰醋酸)=67.5:32.5,检测波长211nm。结果:平均回收率为98.41%,光叶番荔枝树皮、光叶番荔枝树枝(去皮)、光叶番荔枝树叶、AP番荔枝树叶、牛心番荔枝树叶、山刺番荔枝树叶中化合物ent-kaur-16-en-19-oic ac id的含量分别为0.7147%、0.01252%、0.01773%、0.04212%、0.007305%、0.09083%。结论:在光叶番荔枝各部位中,树皮的含量最高,达0.7147%,在所测番荔枝属植物的树叶中,山刺番荔枝树叶中含量最高,达0.09083%。展开更多
Uniqueness results are obtained for positive solutions of a class of quasilinear ordinary differential equations.The methods rely on the energy analysis and a scale argument.
Using the minitransposon pMini-Tn5 and the ice-nucleation active (INA) gene of iceA, a suicide recombinant plasmid pTnice1 was constructed, which has the ability of broad-host-range conjugal mobilization and integrati...Using the minitransposon pMini-Tn5 and the ice-nucleation active (INA) gene of iceA, a suicide recombinant plasmid pTnice1 was constructed, which has the ability of broad-host-range conjugal mobilization and integration of iceA into chromosomal DNA of many gram-negative bacteria by Tn5 transposition. We used this plasmid to integrate the iceA into chromosomal DNA of Ent. cloacae and obtained the transgentic strain Enc1.2022 ina. In this transgenic Ent. cloacae, iceA would never be transferred elsewhere through transposition, and constantly expressed high ice nucleation activity even in the absence of antibiotic pressure. The transgenic strain was ingested by corn borer larvae. Over the 7 d after ingestion, the mean supercooling points (SCPs) of the larvae was about 10℃ higher than those of larvae treated with distilled water (control). The maintenance of these high SCPs was related to the stable gut colonization of transgenic strain. At 6th day post ingestion, the larva was exposed at 5 or 7℃ for 12 h, the percentages of larvae frozen to death were 85 and 100%, respectively. In contrast, none or a small proportion of control larvae was frozen to death under the same conditions. Further studies demonstrated that this transgenic strain bore weak epiphytic ability. Therefore, this genetically engineered strain may be a promising candidate for control of insect pests in agricultural fields.展开更多
文摘A fully differential R-MOSFET-C fourth-order Bessel active lowpass filter employing fully differential operational amplifier,passive resistors,and current-steering MOS transistors as a variable resistor is proposed.This proposed implementation relies on the tunability of current-steering MOS transistors operating in the triode region counteracting the concert deviation of resistor in the integrated circuit manufacturing technology in orde r that the group delay of Bessel active filter could be designed accurately.The amplifier is not only with voltage common-mode negative feedback,but also with current common-mode negative feedback,which will benefit for the stability of its D C operating point.0.75μs group delay fourth-order Bessel lowpass filter,whic h is synthesized according to passive doubly terminated RLC prototype lowpass filter,demonstrates better than -65dB THD using 100kHz,2.5V pp signal in Taiwan UMC 2P2M(2-poly,2-metal)5.0V,0.5μm CMOS technology.
文摘目的:采用高效液相色谱法测定化合物ent-kaur-16-en-19-oic ac id在光叶番荔枝不同部位和番荔枝属不同种类植物叶子中的含量。方法:色谱条件为:Nuc leosil C18色谱柱,流动相选用乙睛:水(含1%冰醋酸)=67.5:32.5,检测波长211nm。结果:平均回收率为98.41%,光叶番荔枝树皮、光叶番荔枝树枝(去皮)、光叶番荔枝树叶、AP番荔枝树叶、牛心番荔枝树叶、山刺番荔枝树叶中化合物ent-kaur-16-en-19-oic ac id的含量分别为0.7147%、0.01252%、0.01773%、0.04212%、0.007305%、0.09083%。结论:在光叶番荔枝各部位中,树皮的含量最高,达0.7147%,在所测番荔枝属植物的树叶中,山刺番荔枝树叶中含量最高,达0.09083%。
文摘Uniqueness results are obtained for positive solutions of a class of quasilinear ordinary differential equations.The methods rely on the energy analysis and a scale argument.
基金This work was supported by the National Natural Science Foundation of China(30170624).
文摘Using the minitransposon pMini-Tn5 and the ice-nucleation active (INA) gene of iceA, a suicide recombinant plasmid pTnice1 was constructed, which has the ability of broad-host-range conjugal mobilization and integration of iceA into chromosomal DNA of many gram-negative bacteria by Tn5 transposition. We used this plasmid to integrate the iceA into chromosomal DNA of Ent. cloacae and obtained the transgentic strain Enc1.2022 ina. In this transgenic Ent. cloacae, iceA would never be transferred elsewhere through transposition, and constantly expressed high ice nucleation activity even in the absence of antibiotic pressure. The transgenic strain was ingested by corn borer larvae. Over the 7 d after ingestion, the mean supercooling points (SCPs) of the larvae was about 10℃ higher than those of larvae treated with distilled water (control). The maintenance of these high SCPs was related to the stable gut colonization of transgenic strain. At 6th day post ingestion, the larva was exposed at 5 or 7℃ for 12 h, the percentages of larvae frozen to death were 85 and 100%, respectively. In contrast, none or a small proportion of control larvae was frozen to death under the same conditions. Further studies demonstrated that this transgenic strain bore weak epiphytic ability. Therefore, this genetically engineered strain may be a promising candidate for control of insect pests in agricultural fields.
