A new approach to high-order Boussinesq-type equations with ambient currents is presented. The current velocity is assumed to be uniform over depth and of the same magnitude as the shallow water wave celerity. The wav...A new approach to high-order Boussinesq-type equations with ambient currents is presented. The current velocity is assumed to be uniform over depth and of the same magnitude as the shallow water wave celerity. The wave velocity field is expressed in terms of the horizontal and vertical wave velocity components at an arbitrary water depth level. Linear operators are introduced to improve the accuracy of the kinematic condition at the sea bottom. The dynamic and kinematic conditions at the free surface are expressed in terms of wave velocity variables defined directly on the free surface. The new equations provide high accuracy of linear properties as well as nonlinear properties from shallow to deep water, and extend the applicable range of relative water depth in the case of opposing currents.展开更多
Background Atrial fibrillation （AF） is the most common sustained cardiac arrhythmia without effective treatment. AF is associated with atrial conduction disturbances caused by electrical and / or structural remodeli...Background Atrial fibrillation （AF） is the most common sustained cardiac arrhythmia without effective treatment. AF is associated with atrial conduction disturbances caused by electrical and / or structural remodeling. But the role of connexin （Cx） 43 in the regulation of L type calcium channel （LCC） remains unclear. We hypothesized that Cx 43 might co-localize and regulate the L type calcium channel current （ICa, D. Methods Real-time PCR and whole-cell patch clamp were used to detect the expression of LCC lc subunit and the cur rent density of Ica, L, before and after Cx 43 knocking down respectively. The co-localization of Cx 43 with LCC was investigated by co-immunoprecipitation and confocal microscopy. Results Knocking down of Cx43 significantly inhibited the current density of ICa, L through decreasing the gene expression of LCC alc in cul tured atrium-derived myocytes （HL-1 cells）. Cx43 co-localized with LCC eric subunit in atrial myocytes. Conclusions Cx 43 regulates the ICa, L in atrial myoctyes through LCC, representing a potential pathogenic mechanism in atrial arrhythmias.展开更多
This paper analyzes characteristics of multi type current transformers hybrid operation for each branch of the bus and their effects on differential protection of the bus. By theoretically analyzing transmission chara...This paper analyzes characteristics of multi type current transformers hybrid operation for each branch of the bus and their effects on differential protection of the bus. By theoretically analyzing transmission characteristics of multi type current transformers and their influence factors, we study the dynamic model testing method of multi type current transformers for the bus, and design 3 kinds of testing schemes by making the equivalent model based on the field of P-level current transformer, TPY-level current transformer and electronic current transformer, and build the hybrid operation testing platform of multi type current transformers. Finally, we compare and analyze the transmission characteristics difference of multi type current transformers on the same branch and the characteristics difference of hybrid operation in two successive external faults, analyze the cause behind the differences, and put forward the corresponding improvement measures.展开更多
Objectives Heart failure （HF） is one of the most common outcome for all kinds of heart diseases, the effects of energetic therapy on HF remains controversial, especially to ischemic HF. The aim of this study was to ...Objectives Heart failure （HF） is one of the most common outcome for all kinds of heart diseases, the effects of energetic therapy on HF remains controversial, especially to ischemic HF. The aim of this study was to explore the effect of exogenous phosphocreatine with different concentration on L-type calcium（I Cc-L） current in ischemic ventricular myocytes of guinea pig and to investigate its underlying electrophysiological mechanism for the treatment of ischemic HF. Methods Single ventricular myocytes were isolated enzymatically from left ventricle of guinea pig. Peak I Ca-L current were recorded using patch clamp techniques in the whole-cell configuration when myocytes had been superfused with normal Tyrode solution, simple ischemic solution, ischemic solution containing phosphocreatine with different concentration for 10 minutes respectively. Results Peak I Ca-L current density of myocytes superfused with simple simulated ischemic solution was remarkably inhibited by 80.6 ± 5.2% compared with myocytes superfused with normal Tyrode solution（P〈0.05）. Ischemic solution containing phosphocreatine of 5, 10, 20, 30mmol/L inhibited Peak I Ca-L current density by （53.8±6.7）%, （41.8 ± 8.2）%, （38.1±7.4）%, （36.6±9.7）% respectively. There was no statistical significance among phosphocreation of 10, 20, 30 mmol / L. Conclusions Extrogenous phosphocreatine could reverse the inhibition of I Ca-L current under ischemic condition, which could be the ionic basis for the treatment of ischemic heart failure. 0-10 mmol/L phosphocreatine exerted significant dose-effect relationship which no longer existed as concentration more than 10 mmol/L. It is supposed that phosphocreatine increased I Ca-L current by many pathways rather than simple substrate for ATP synthesis.展开更多
A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main dischar...A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseu- dospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface ttashover trigger device made of high relative perimittivity dielectric material BaTiO3 （εr = 3460）, the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current waveform of maximum 25 kA was generated with a rise time and time to half peak value of 17.2 μs and 336μs respectively.展开更多
为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方...为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方法,通过精确调控吸收层掺杂、势垒层掺杂、势垒层厚度、温度和组分等,构建出高能量势垒以有效阻挡多数载流子,允许少数载流子迁移,实现价带偏移(Valence Band Offset,VBO)接近于零的要求,从而有效降低暗电流。研究结果表明,在1×10^(15)~1×10^(17)cm^(-3)范围内降低势垒层掺杂浓度,VBO和暗电流开启电压绝对值均会减小,当AlAs1-xSbx势垒中Sb组分为0.91时,VBO接近于零。对于吸收层,随着掺杂浓度的提高,暗电流呈现减小趋势,但趋势较不明显。在-0.5V偏压,140 K工作条件下,吸收层和势垒层掺杂浓度分别为1×10^(13)cm^(-3),1×10^(15)cm^(-3),吸收层与势垒层厚度分别为3μm,80 nm,得到器件结构参数优化后的暗电流低至4.5×10^(-7)A/cm^(2),证明InAs/InAsSb中波红外探测器具有高温工作的应用前景,可广泛应用于导弹预警、红外制导、航空航天等领域。展开更多
基金This work was financially supported by the Science Foundation of National Education Committee of China (Grant No.40106008) and by LED, South China Sea Institute of Oceanology, Chinese Academy of Sciences.
文摘A new approach to high-order Boussinesq-type equations with ambient currents is presented. The current velocity is assumed to be uniform over depth and of the same magnitude as the shallow water wave celerity. The wave velocity field is expressed in terms of the horizontal and vertical wave velocity components at an arbitrary water depth level. Linear operators are introduced to improve the accuracy of the kinematic condition at the sea bottom. The dynamic and kinematic conditions at the free surface are expressed in terms of wave velocity variables defined directly on the free surface. The new equations provide high accuracy of linear properties as well as nonlinear properties from shallow to deep water, and extend the applicable range of relative water depth in the case of opposing currents.
基金supported by National Natural Science Foundation of China(No.81470440)Guangdong Natural Science Foundation(No.S2013010016256)Medical Scientific Research Foundation of Guangdong Province(No.A2013049)
文摘Background Atrial fibrillation （AF） is the most common sustained cardiac arrhythmia without effective treatment. AF is associated with atrial conduction disturbances caused by electrical and / or structural remodeling. But the role of connexin （Cx） 43 in the regulation of L type calcium channel （LCC） remains unclear. We hypothesized that Cx 43 might co-localize and regulate the L type calcium channel current （ICa, D. Methods Real-time PCR and whole-cell patch clamp were used to detect the expression of LCC lc subunit and the cur rent density of Ica, L, before and after Cx 43 knocking down respectively. The co-localization of Cx 43 with LCC was investigated by co-immunoprecipitation and confocal microscopy. Results Knocking down of Cx43 significantly inhibited the current density of ICa, L through decreasing the gene expression of LCC alc in cul tured atrium-derived myocytes （HL-1 cells）. Cx43 co-localized with LCC eric subunit in atrial myocytes. Conclusions Cx 43 regulates the ICa, L in atrial myoctyes through LCC, representing a potential pathogenic mechanism in atrial arrhythmias.
文摘This paper analyzes characteristics of multi type current transformers hybrid operation for each branch of the bus and their effects on differential protection of the bus. By theoretically analyzing transmission characteristics of multi type current transformers and their influence factors, we study the dynamic model testing method of multi type current transformers for the bus, and design 3 kinds of testing schemes by making the equivalent model based on the field of P-level current transformer, TPY-level current transformer and electronic current transformer, and build the hybrid operation testing platform of multi type current transformers. Finally, we compare and analyze the transmission characteristics difference of multi type current transformers on the same branch and the characteristics difference of hybrid operation in two successive external faults, analyze the cause behind the differences, and put forward the corresponding improvement measures.
文摘Objectives Heart failure （HF） is one of the most common outcome for all kinds of heart diseases, the effects of energetic therapy on HF remains controversial, especially to ischemic HF. The aim of this study was to explore the effect of exogenous phosphocreatine with different concentration on L-type calcium（I Cc-L） current in ischemic ventricular myocytes of guinea pig and to investigate its underlying electrophysiological mechanism for the treatment of ischemic HF. Methods Single ventricular myocytes were isolated enzymatically from left ventricle of guinea pig. Peak I Ca-L current were recorded using patch clamp techniques in the whole-cell configuration when myocytes had been superfused with normal Tyrode solution, simple ischemic solution, ischemic solution containing phosphocreatine with different concentration for 10 minutes respectively. Results Peak I Ca-L current density of myocytes superfused with simple simulated ischemic solution was remarkably inhibited by 80.6 ± 5.2% compared with myocytes superfused with normal Tyrode solution（P〈0.05）. Ischemic solution containing phosphocreatine of 5, 10, 20, 30mmol/L inhibited Peak I Ca-L current density by （53.8±6.7）%, （41.8 ± 8.2）%, （38.1±7.4）%, （36.6±9.7）% respectively. There was no statistical significance among phosphocreation of 10, 20, 30 mmol / L. Conclusions Extrogenous phosphocreatine could reverse the inhibition of I Ca-L current under ischemic condition, which could be the ionic basis for the treatment of ischemic heart failure. 0-10 mmol/L phosphocreatine exerted significant dose-effect relationship which no longer existed as concentration more than 10 mmol/L. It is supposed that phosphocreatine increased I Ca-L current by many pathways rather than simple substrate for ATP synthesis.
文摘A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseu- dospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface ttashover trigger device made of high relative perimittivity dielectric material BaTiO3 （εr = 3460）, the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current waveform of maximum 25 kA was generated with a rise time and time to half peak value of 17.2 μs and 336μs respectively.
文摘为提高势垒型中波InAs/InAsSb二类超晶格红外探测器器件性能,研究并设计了nBn势垒型InAs/InAsSb器件结构。针对InAs/InAsSb红外探测器器件结构特征,分析了暗电流的主导机制和能带特性,采用基于泊松方程、连续性方程和热方程的数值计算方法,通过精确调控吸收层掺杂、势垒层掺杂、势垒层厚度、温度和组分等,构建出高能量势垒以有效阻挡多数载流子,允许少数载流子迁移,实现价带偏移(Valence Band Offset,VBO)接近于零的要求,从而有效降低暗电流。研究结果表明,在1×10^(15)~1×10^(17)cm^(-3)范围内降低势垒层掺杂浓度,VBO和暗电流开启电压绝对值均会减小,当AlAs1-xSbx势垒中Sb组分为0.91时,VBO接近于零。对于吸收层,随着掺杂浓度的提高,暗电流呈现减小趋势,但趋势较不明显。在-0.5V偏压,140 K工作条件下,吸收层和势垒层掺杂浓度分别为1×10^(13)cm^(-3),1×10^(15)cm^(-3),吸收层与势垒层厚度分别为3μm,80 nm,得到器件结构参数优化后的暗电流低至4.5×10^(-7)A/cm^(2),证明InAs/InAsSb中波红外探测器具有高温工作的应用前景,可广泛应用于导弹预警、红外制导、航空航天等领域。
