Fluorescence and absorption characteristics of p-xylene: applicability for temperature measurements

Estimation of the chain propagation rate constants of propylene polymerization and ethylene‐1‐hexene copolymerization catalyzed with MgCl2‐supported Ziegler–Natta catalysts

“…A relatively moderate decline of ( k p ) a with time was observed in 1‐hexene polymerization, in which the polymer is soluble in hydrocarbon medium. [ 23,24 ] A similar decline of ( k p ) a with time has been observed in ethylene and propylene polymerization with homogeneous metallocene catalysts. [ 25,26 ] It seems that the non‐crystalline polymer phase surrounding the catalyst fragment of heterogeneous Z–N catalyst or the semi‐crystalline polymer surrounding molecular catalyst can also cause diffusion limitation in catalytic polymerization.…”

“…It was proved that both TiCH 2 CHR~ type active centres (active for olefin insertion) and TiCHRCH 2 ~ type active centres (dormant site) can be quantitatively labelled by TPCC, and the possible side reactions between Al‐P~ (P~ denotes polyolefin chain) were negligible under the conditions used in the quenching reaction. [ 24,29 ] Therefore, each chain propagation centre (either active or dormant) is labelled with a sulphur atom by the TPCC quenching. The number of active centres was determined by measuring the sulphur content of the quench‐labelled sample (after thoroughly purifying the sample).…”

“…Similar phenomena have been observed in our previous studies, and were explained by gradual release of the active centre precursors buried inside the catalyst particle. [ 13,14,20–24,31 ] Expansion of the polymer phase in the voids and cracks of catalyst particles has been proposed as the source of this phenomenon.…”

Elucidating Structure Formation in Highly Oriented Triple Cation Perovskite Films

“…In addition to the size of the perovskite grains, recent studies suggest that their relative orientation with respect to the substrate and each other might impact the photovoltaic performance. [ 18 ] For example, Yang et al reported that the addition of caffeine into the perovskite solution results in a preferential orientation of the perovskite grains along the (110) planes. The authors suggest that this preferential orientation improves charge transport in the device, leading to enhanced photovoltaic performance.…”

Coexisting spin-flop coupling and exchange bias in LaFeO3/La0.7Sr0.3Olsen1, Hallsteinsen2, Arenholz3 et al. 2019Phys. Rev. B6050View full textAdd to dashboardCite

“…[8][9][10] In most systems EB is obtained by field cooling (FC) the AF/FM system through the AF ordering temperature, T N . However, spontaneous EB that does not require field cooling has been reported, e.g., in Fe/Cr 2 O 3 /Fe trilayers 11 and Ni-Mn-Sn alloys 12 and recently also in perovskite systems such as polycrystalline La 1.5 Sr 0.5 CoMnO 6 , 13 and La 0.7 Sr 0.3 MnO 3 /Eu 0.45 Sr 0.55 MnO 3 heterostructures. 14 A shift of the hysteresis loop in the opposite direction of the cooling field is most commonly observed (negative EB), but a loop shift in the cooling field direction (positive EB) has also been reported.…”