A novel transition appeared above thc glass transition temperature of chlorinated polyethylene (CPE) for binaryblends of CPE and additives such as organic small molecules or oligomers. This transition was assigned to ...A novel transition appeared above thc glass transition temperature of chlorinated polyethylene (CPE) for binaryblends of CPE and additives such as organic small molecules or oligomers. This transition was assigned to the dissociation ofintermolecular hydrogen bonds between the polymer ard additive within the edditive rich phase. Of particular interest is thata novel pyramid crystal was observed in the annealed CPE/hindered phenol blends. Another intriguing observation is thatthese polymer/small molecule blends organized by intermolecular hydrogen bonding have several potential properties, suchas shape-memorization, self-restoration, self-adhesiveness and super damping.展开更多
A new bipolar temperature-compensated current reference is proposed. The first-order temperature compensation is achieved by the idea of self temperature-compensation configuration exploiting the temperature coefficie...A new bipolar temperature-compensated current reference is proposed. The first-order temperature compensation is achieved by the idea of self temperature-compensation configuration exploiting the temperature coefficient of a combined resistor. The second-order compensation employs a VBE-tracking thermal-startup technique to obtain improved temperature performance. The proposed circuit can operate down to a 1-V supply. A temperature coefficient of 46.6×10?6/℃ [0, 100℃] at a 1-V supply and a supply regulation of 0.036%/V at 25℃ are achieved. Compared with present works, the proposed circuit shows better results of the temperature coefficient and supply regulation. The current matching issue frequently encountered in current references is also discussed in detail.展开更多
The Cu-24 Pb-x Sn(wt%)(x=0,2,4,6)alloys with Pb-rich second-phase particles(SPPs)in different shapes show obviously differently mechanical and self-lubricating properties.The influence of the SPPs’shape difference on...The Cu-24 Pb-x Sn(wt%)(x=0,2,4,6)alloys with Pb-rich second-phase particles(SPPs)in different shapes show obviously differently mechanical and self-lubricating properties.The influence of the SPPs’shape difference on the alloys’mechanical and self-lubricating properties was revealed.Cu-24 Pb alloy with continuously netty SPPs shows much more intensive stick-slip phenomenon during dry sliding than the other three alloys with independently rodlike SPPs.That is mainly due to insufficient lubrication resulted by the netty SPPs’splitting matrix.With the SPPs transforming from netty to rodlike shape under the addition of Sn,the stick-slip phenomenon was notably weakened,which was proven to be related to the higher self-lubricating property of alloys with rodlike SPPs.Simultaneously,the simultaneous increase of ductility and tensile strength was observed in the Cu-24 Pb-x Sn alloys with increasing Sn content,which is because the netty SPPs’splitting behavior will be weakened with them replaced by the rodlike SPPs.展开更多
低压电气系统的负载特性随时间变化,具有非线性关系,导致电压穿越能力协调控制效果差。为解决该问题,引入二阶线性自抗扰技术对低压电气设备电压穿越能力进行协调控制。通过构建二阶线性微分方程分析低压电气设备动态响应特性,确定影响...低压电气系统的负载特性随时间变化,具有非线性关系,导致电压穿越能力协调控制效果差。为解决该问题,引入二阶线性自抗扰技术对低压电气设备电压穿越能力进行协调控制。通过构建二阶线性微分方程分析低压电气设备动态响应特性,确定影响动态响应特性的关键因素。同时,考虑得到的是低压电气设备动态响应特性的关键因素,设计二阶线性自抗干扰控制器(Second-Order Linear Active Disturbance Rejection Controller,SOLADRC),并采用自适应算法实时调整控制器的参数。最后,依据不同电压进行扰动自适应协调,实现低压电气设备电压穿越能力自适应协调控制。通过仿真实验证实,该策略在不同电压扰动条件下能有效缩短电压恢复时间,增强系统健壮性,为提高低压电气设备的电压穿越能力提供理论支持和实践参考。展开更多
文摘A novel transition appeared above thc glass transition temperature of chlorinated polyethylene (CPE) for binaryblends of CPE and additives such as organic small molecules or oligomers. This transition was assigned to the dissociation ofintermolecular hydrogen bonds between the polymer ard additive within the edditive rich phase. Of particular interest is thata novel pyramid crystal was observed in the annealed CPE/hindered phenol blends. Another intriguing observation is thatthese polymer/small molecule blends organized by intermolecular hydrogen bonding have several potential properties, suchas shape-memorization, self-restoration, self-adhesiveness and super damping.
文摘A new bipolar temperature-compensated current reference is proposed. The first-order temperature compensation is achieved by the idea of self temperature-compensation configuration exploiting the temperature coefficient of a combined resistor. The second-order compensation employs a VBE-tracking thermal-startup technique to obtain improved temperature performance. The proposed circuit can operate down to a 1-V supply. A temperature coefficient of 46.6×10?6/℃ [0, 100℃] at a 1-V supply and a supply regulation of 0.036%/V at 25℃ are achieved. Compared with present works, the proposed circuit shows better results of the temperature coefficient and supply regulation. The current matching issue frequently encountered in current references is also discussed in detail.
基金supported financially by the National Key Research and Development Program of China(Nos.2016YFB0301303 and 2017YFB0306105)the National Natural Science Foundation of China(Nos.51871041,51771040and51690163)the Fundamental Research Funds for the Central Universities of China(No.DUT17JC44).
文摘The Cu-24 Pb-x Sn(wt%)(x=0,2,4,6)alloys with Pb-rich second-phase particles(SPPs)in different shapes show obviously differently mechanical and self-lubricating properties.The influence of the SPPs’shape difference on the alloys’mechanical and self-lubricating properties was revealed.Cu-24 Pb alloy with continuously netty SPPs shows much more intensive stick-slip phenomenon during dry sliding than the other three alloys with independently rodlike SPPs.That is mainly due to insufficient lubrication resulted by the netty SPPs’splitting matrix.With the SPPs transforming from netty to rodlike shape under the addition of Sn,the stick-slip phenomenon was notably weakened,which was proven to be related to the higher self-lubricating property of alloys with rodlike SPPs.Simultaneously,the simultaneous increase of ductility and tensile strength was observed in the Cu-24 Pb-x Sn alloys with increasing Sn content,which is because the netty SPPs’splitting behavior will be weakened with them replaced by the rodlike SPPs.
文摘低压电气系统的负载特性随时间变化,具有非线性关系,导致电压穿越能力协调控制效果差。为解决该问题,引入二阶线性自抗扰技术对低压电气设备电压穿越能力进行协调控制。通过构建二阶线性微分方程分析低压电气设备动态响应特性,确定影响动态响应特性的关键因素。同时,考虑得到的是低压电气设备动态响应特性的关键因素,设计二阶线性自抗干扰控制器(Second-Order Linear Active Disturbance Rejection Controller,SOLADRC),并采用自适应算法实时调整控制器的参数。最后,依据不同电压进行扰动自适应协调,实现低压电气设备电压穿越能力自适应协调控制。通过仿真实验证实,该策略在不同电压扰动条件下能有效缩短电压恢复时间,增强系统健壮性,为提高低压电气设备的电压穿越能力提供理论支持和实践参考。
