文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射...文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射下,驱动丙烯酸甲酯(MA)和甲基丙烯酸甲酯(MMA)的P-ATRP反应且单体转化率达到99%。所得聚合物的结构明确,分子量可控,分子量分布(D-_(s)<1.18)窄。在太阳光照射条件下,TPP-CHCP依然具有优异的光催化活性,可高效制备嵌段共聚物。展开更多
目前电磁时间反演(electromagnetic time reversal,EMTR)多应用在单一线路故障定位,且现有判据在高阻抗接地情况下效果不理想。针对上述问题,基于EMTR故障定位原理和均匀传输线理论推导了传播过程中线路故障信号与测量信号的传递函数,...目前电磁时间反演(electromagnetic time reversal,EMTR)多应用在单一线路故障定位,且现有判据在高阻抗接地情况下效果不理想。针对上述问题,基于EMTR故障定位原理和均匀传输线理论推导了传播过程中线路故障信号与测量信号的传递函数,根据传递函数的相关性提出了P范数判据。利用ATP-EMTP搭建10 kV配电网线路,对比了2范数与P范数判据在复杂配电网中的定位性能,并验证了所提判据在混合配电网线路的适用性。最后,分析了配电网发生低阻抗及高阻抗接地故障下P范数判据的鲁棒性。仿真结果表明,该方法在过渡电阻高达3 kΩ的情况下能准确定位,且定位精度高,受噪声、故障类型和采样频率的影响小。展开更多
The increase of the critical temperature Tc for superconductivity in Al1−x(SiO2)x cermets with increasing x correlates with a decrease of the electron density n due to electron transfer, expressed by Tc/Tc,max=1−γ⋅n2...The increase of the critical temperature Tc for superconductivity in Al1−x(SiO2)x cermets with increasing x correlates with a decrease of the electron density n due to electron transfer, expressed by Tc/Tc,max=1−γ⋅n2(*). Behind the formula (*) and Tc/Tc,max=1−82.6(P−0.16)2, which is characteristic of hole-doped cuprat high-temperature superconductors, lies a general phenomenon, namely electron transfer, which equalizes potential differences in the material and leads to a strong reduction of n. P is the fraction of holes filled by the transferred electrons. A quantitative consideration gives Tc(x)/Tc,max=1−(1−x1−x0)2(**), where x is the doping concentration and x0 is the concentration at which superconductivity begins. At x=xmax=1the electron source is completely depleted and with further growth of x the hole density p starts to increase and Tc decreases until superconductivity disappears completely at x=2−x0. Taking into account the formula (**), the hypothesis arose that for x>xmaxTc/Tc,max=1−γ⋅p2(***), an analogue of the formula (*), and that superconductivity is possible not only by electron-Cooper pairs but also by paired holes. The mechanisms described here for HTSC suggest an analogy to the physics of semiconductors and that of nanocomposites: Electron-hole duality. The “P=1/8” anomaly in YBa2Cu3O6+x is caused by the simultaneous presence of electrons and holes, a consequence of incomplete electron transfer.展开更多
文摘文章通过两步反应合成共轭超交联聚合物(TPP-CHCP)。TPP-CHCP有较宽的光吸收区间(400~900 nm),可作为光致原子转移自由基聚合(photocatalyzed atom transfer radical polymerization,P-ATRP)的光催化剂。TPP-CHCP可在940 nm近红外光照射下,驱动丙烯酸甲酯(MA)和甲基丙烯酸甲酯(MMA)的P-ATRP反应且单体转化率达到99%。所得聚合物的结构明确,分子量可控,分子量分布(D-_(s)<1.18)窄。在太阳光照射条件下,TPP-CHCP依然具有优异的光催化活性,可高效制备嵌段共聚物。
文摘目前电磁时间反演(electromagnetic time reversal,EMTR)多应用在单一线路故障定位,且现有判据在高阻抗接地情况下效果不理想。针对上述问题,基于EMTR故障定位原理和均匀传输线理论推导了传播过程中线路故障信号与测量信号的传递函数,根据传递函数的相关性提出了P范数判据。利用ATP-EMTP搭建10 kV配电网线路,对比了2范数与P范数判据在复杂配电网中的定位性能,并验证了所提判据在混合配电网线路的适用性。最后,分析了配电网发生低阻抗及高阻抗接地故障下P范数判据的鲁棒性。仿真结果表明,该方法在过渡电阻高达3 kΩ的情况下能准确定位,且定位精度高,受噪声、故障类型和采样频率的影响小。
文摘The increase of the critical temperature Tc for superconductivity in Al1−x(SiO2)x cermets with increasing x correlates with a decrease of the electron density n due to electron transfer, expressed by Tc/Tc,max=1−γ⋅n2(*). Behind the formula (*) and Tc/Tc,max=1−82.6(P−0.16)2, which is characteristic of hole-doped cuprat high-temperature superconductors, lies a general phenomenon, namely electron transfer, which equalizes potential differences in the material and leads to a strong reduction of n. P is the fraction of holes filled by the transferred electrons. A quantitative consideration gives Tc(x)/Tc,max=1−(1−x1−x0)2(**), where x is the doping concentration and x0 is the concentration at which superconductivity begins. At x=xmax=1the electron source is completely depleted and with further growth of x the hole density p starts to increase and Tc decreases until superconductivity disappears completely at x=2−x0. Taking into account the formula (**), the hypothesis arose that for x>xmaxTc/Tc,max=1−γ⋅p2(***), an analogue of the formula (*), and that superconductivity is possible not only by electron-Cooper pairs but also by paired holes. The mechanisms described here for HTSC suggest an analogy to the physics of semiconductors and that of nanocomposites: Electron-hole duality. The “P=1/8” anomaly in YBa2Cu3O6+x is caused by the simultaneous presence of electrons and holes, a consequence of incomplete electron transfer.
