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Although the amorphous two-dimensional electron gas (a-2DEG) of oxides provides new opportunities to explore nanoelectronic as well as quantum devices, the intrinsic effect of rare earth (Re = La, Pr, Nd, Sm, Gd, and Tm) elements at ReAlO 3 /SrTiO 3 heterointerfaces is still largely unknown and needs to be addressed systematically. Herein, we first propose that the ionization potential of Re elements is a critical factor for the 2DEG fabricated by chemical spin coating. Furthermore, the photoresponsive properties of heterointerfaces are investigated comprehensively with the ionization potential ranging from 35.79 to 41.69 eV. The results show that the sheet resistances significantly increase with increasing the ionization potential, and a resistance upturn phenomenon is observed at TmAlO 3 /SrTiO 3 heterointerfaces, which can be attributed to the weak localization effect theoretically. The most important observation is the dramatic transition from negative (−178.3%, Re = La) to positive (+89.9%, Re = Gd) photoresponse at ReAlO 3 /SrTiO 3 heterointerfaces under the irradiation of 405 nm light at 50 K. More remarkably, a unique recovery behavior of transient−persistent photoconductivity coexistence at low temperatures is discovered at the TmAlO 3 /SrTiO 3 heterointerface. This work reveals an effective approach to tune the transport and photoresponsive properties by changing Re elements and paves the way for the application of all-oxide devices.

Oxygen vacancies doping in oxide materials is a very common means to modulate the electrical transport properties. In this work, Y3Fe5O12 (YIG) films with abundant oxygen vacancies were grown on Gd3Ga5O12 (GGG) substrates by solution spin coating and high vacuum annealing method, and the effect of oxygen vacancies on the electrical transport properties was systematically studied. It was found that a large amount of oxygen vacancies doping could convert the YIG film from a good room-temperature insulator to an electrical conductor. At high temperature and high vacuum, a large number of oxygen vacancies increased the disorder of the system, resulting in the appearance of a band-tail state, thus forming a constant range hopping conduction. While when the sample was exposed to air, the oxygen vacancies in the sample would gradually recombine and disappear, and the conduction mechanism transferred to drift mode.

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Geographic object flow is the reason behind the relationship of geographic units. There are interactions in the process of dynamic change of a geographic object flow, and its regularity, which can reflect the relationship or pattern of geographic units in a region. In this paper, an association rule mining method for the geographic object flow linkage process is studied from a geoeconomics perspective. Additionally, an association rule mining algorithm with hierarchical constraints is proposed. Data segmentation is performed according to the time series characteristics of geographic object flow data. The basic attributes for the association rule mining are determined based on the basic parameters of geographic object flows, and a database for the association rule mining is formed according to the characteristics of the hierarchical structure of the geographic object flows. Based on the obtained data, the association rule mining algorithm with hierarchical constraints obtained using a parent–child matrix is improved by adding the Apriori algorithm. With the Indo-Pacific region as an example, the trade flow association rules for 25 countries in the region from 2010 to 2021 are selected. In addition, a mathematical statistical analysis of the strongly associated mined trade flows and geoeconomic factors is conducted in terms of both a basic feature analysis of trade flow associations and a country-oriented trade flow association analysis by considering domain knowledge. The effectiveness of the method has been evaluated from various perspectives such as correlation analysis, mathematical statistics, and comparison with the findings of existing studies and proved the validity of the method.