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Complexity of service environment and particularity of the transportation medium make it difficult to develop a nondestructive stress testing on oil and gas pipelines in real time and online. In this case, a stress detection method of oil and gas pipelines is proposed in this work based on the magnetic mechanical properties of pipeline steel materials and the magnetic induction intensity stress coupling relationship. Six commonly used pipeline steels (X52, X56, X60, X65, X70, and X80) are selected as the research objects to test the hysteresis curves. The key parameters of local magnetization of oil and gas pipelines are determined based on their magnetic properties. A finite element simulation model is established for oil and gas pipelines with magnetic field and stress field coupling. The magnetic field distribution and magnetic induction intensity along the length of the pipeline and the height of cross section are studied after local magnetization of the simulation model of oil and gas pipelines unpressurized. The mechanism of magnetic induction intensity and stress variation of the simulation model of oil and gas pipelines with different internal pressures are discussed. The coupling relationship of axial stress, circumferential stress, and magnetic induction intensity are separately established. The systems for stress-strain test and magnetic induction intensity test are integrated to test the X80 pipeline steel. Analysis results on test data and finite element simulation data verify the validity of magnetic coupling simulation of oil and gas pipelines and the reliability of stress detection, which provides a theoretical basis for the key technologies of nondestructive online stress detection of oil and gas pipelines.

Automatic image registration of multimodal urban remote sensing images remains a critical challenging task in remote sensing image analysis due to significant nonlinear radiation distortions between multimodal image pairs; most of the traditional methods focus on the feature point detection and its local description and ignore the robust road information in multimodal urban remote sensing images. Motivated by this, we propose a fast and robust registration method for multimodal urban remote sensing images via road intersection triangular features. The proposed method obtains three main stages: Road lines extraction from images, intersection triangular feature construction, and triangular feature matching. The qualitative and quantitative experimental results show that the proposed method significantly outperforms other state-of-the-art methods, even when others completely fail to achieve the registration task of cross-modal images, our method still maintains good robustness and matching efficiency.

Two-dimensional electron gas (2DEG) at the interface between two insulating perovskite oxides has attracted much interest for both fundamental physics and potential applications. Here, we report the discovery of a new 2DEG formed at the interface between spinel MgAl

The search for new superconductors capable of carrying loss-free current has been a research theme in condensed matter physics for the past decade. Among superconducting compounds, titanates have not been pursued as much as Cu2+ (3d9) (cuprate) and Fe2+ (3d6) (pnictide) compounds. Particularly, Ti3+-based compounds or electron systems with a special 3d1 filling are thought to be promising candidates as high-TC superconductors, but there has been no report on such pure Ti3+-based superconducting titanates. With the advent of thin-film growth technology, stabilizing new structural phases in single-crystalline thin films is a promising strategy to realize physical properties that are absent in the bulk counterparts. Herein, we report the discovery of unexpected superconductivity in orthorhombic-structured thin films of Ti2O3, a 3d1 electron system, which is in strong contrast to the conventional semiconducting corundum-structured Ti2O3. This is the first report of superconductivity in a titanate with a pure 3d1 electron configuration. Superconductivity at 8 K was observed in the orthorhombic Ti2O3 films. Leveraging the strong structure-property correlation in transition-metal oxides, our discovery introduces a previously unrecognized route for inducing emergent superconductivity in a newly stabilized polymorph phase in epitaxial thin films. Researchers have discovered a titanate -based single-crystal film with a rare structure that allows superconductivity to emerge at low temperatures. Titanium (III) oxide, Ti2O3, has garnered recent interest for solar and energy harvesting devices because its electrons are easily excited by electromagnetic radiation. A team led by Tom Wu from University of New South Wales in Sydney, Australia and Shuai Dong from Southeast University in Nanjing, China, report that these electrons have a very high density comparable to metals and are strongly coupled with lattice in constrained thin films. The researchers used a sapphire substrate to direct the growth of nanometer-thick Ti2O3 layers into a solid-state structure not normally found in free-grown crystals. One particular combination of growth temperature and film thickness yielded an orthorhombic crystal phase that exhibited an unusual semiconductor-to-superconductor electronic transition when cooled to 8 K. Polymorph-dependent superconductivity was discovered in orthorhombic-structured Ti2O3 thin films, which is in strong contrast to the conventional semiconducting trigonal corundum-structured Ti2O3. Leveraging on the strong structure-property correlation in transition-metal oxides, our discovery introduces a hitherto unrecognized route towards inducing superconductivity in 3d1 electron systems via polymorph engineering.

Titanium nitride (TiN) exhibits extremely high wear resistance and corrosion resistance, leading to a broad range of applications. Despite the extensive theoretical efforts on the structural stability of TiN under pressure, a few experimental observations of the pressure-induced phase transition through x-ray diffraction are still in debate. Here, the Raman spectra of TiN under pressure are studied in a diamond anvil cell up to 36 GPa. The discontinuity in the pressure dependent phonon frequencies suggests a phase transition at around 5 GPa with the bonding between Ti and N hardly changing. The phase transition is ascribed to an isostructural transition or a vacancy filling mechanism.

We investigated the influence of minor additions of B, Al and Nb that have representative atomic sizes on the glass forming ability (GFA) and stability of Zr-Ni amorphous alloys during mechanical alloying. The results show that the minor addition of B, Al or Nb does not shorten the initial time of the full amorphization reaction or improve the glass forming ability of the Zr-Ni alloys at a low rotation speed. However, B addition can effectively improve the mechanical stability of the amorphous phase against mechanically induced crystallization. Furthermore, the amorphous phase gradually transforms into a metastable fcc-phase with increasing milling time. The addition of Al and Nb that have similar atomic sizes has a similar effect on the GFA and the mechanical stability of the Zr-Ni amorphous phase. Moreover, Al and Nb addition can alter the crystallization behavior and improve the thermal stability of the Zr-Ni amorphous phase.

Association rule mining is one of the most important areas in data mining, which has received a great deal of attention. The purpose of association rule mining is the discovery of association relationships or correlations among a set of items.In this paper, we present an efficient way to find the valid association rules among the infrequent items, which is seldom mentioned and whose importance often get ignored by other researchers. We design a new data structure, called Transactional Co-Occurrence Matrix, in short TCOM, by two passing of the original transactional database. Then the occurrence count of the itemsets and valid association rules will be mined based on TCOM, which combines the advantages of both transactional oriented (horizontal) layout and item oriented (vertical) layout of the database. It turns out that any itemsets could be randomly accessed and counted without full scan of either the original database or the TCOM, which significantly improves the efficiency of the mining processes.

Materials with mesoscopic structural and electronic phase separation, either inherent from synthesis or created via external means, are known to exhibit functionalities absent in the homogeneous counterparts. One of the most notable examples is the colossal magnetoresistance discovered in mixed-valence manganites, where the coexistence of nano- to micrometer-sized phase-separated domains dictates the magnetotransport. However, it remains challenging to pattern and process such materials into predesigned structures and devices. In this work, a direct laser interference irradiation (LII) method is employed to produce periodic stripes in thin films of a prototypical phase-separated manganite Pr0.65 (Ca0.75 Sr0.25 )0.35 MnO3 (PCSMO). LII induces selective structural amorphization within the crystalline PCSMO matrix, forming arrays with dimensions commensurate with the laser wavelength. Furthermore, because the length scale of LII modification is compatible to that of phase separation in PCSMO, three orders of magnitude of increase in magnetoresistance and significant in-plane transport anisotropy are observed in treated PCSMO thin films. Our results show that LII is a rapid, cost-effective and contamination-free technique to tailor and improve the physical properties of manganite thin films, and it is promising to be generalized to other functional materials.

In this paper, we investigate the electric field effect on epitaxial Pr0.65(Ca0.75Sr0.25)0.35MnO3 thin films in electric double-layer transistors. Different from the conventional transistors with semiconducting channels, the sub(micrometer)-scale phase separation in the manganite channels is expected to result in inhomogeneous distribution of mobile carriers and local enhancement of electric field. The field effect is much larger in the low-temperature phase separation region compared to that in the high-temperature polaron transport region. Further enhancement of electroresistance is achieved by applying a magnetic field, and a 250% modulation of resistance is observed at 80 K, equivalent to an increase of the ferromagnetic metallic phase fraction by 0.51%, as estimated by the general effective medium model. Our results illustrate the complementary nature of electric and magnetic field effects in phase-separated manganites, providing insights on such novel electronic devices based on complex oxides. Published version

We report the electrostatic modulation of transport in strained Pr0.65(Ca0.75Sr0.25)0.35MnO3 thin films grown on SrTiO3 by gating with ionic liquid in electric double layer transistors (EDLT). In such manganite films with strong phase separation, a cluster glass magnetic state emerges at low temperatures with a spin freezing temperature of about 99 K, which is accompanied by the reentrant insulating state with high resistance below 30 K. In the EDLT, we observe bipolar and asymmetric modulation of the channel resistance, as well as an enhanced electroresistance up to 200% at positive gate bias. Our results provide insights on the carrier-density-dependent correlated electron physics of cluster glass systems. Published version

Many commonly used electrical resistive switching devices are based on films of metal-oxide-metal ``sandwiches.'' Now scientists have observed ultrafast and reversible resistive switching in a thin-film device composed of a metallic platinum layer and two ultrathin layers of insulating oxides, LaAlO${}_{3}$ and SrTiO${}_{3}$, and revealed its origin in the oxides' charge-carrying oxygen vacancies.

We report on the interfacial magnetic coupling in manganite bilayers of collinear ferromagnetic La0.7 Sr0.3 MnO3 and noncollinear multiferroic TbMnO3. Exchange bias is observed at the Néel temperature of TbMnO3 (∼41 K) due to the onset of long-range antiferromagnetic ordering in the Mn spin sublattice. Interestingly, an anomalous plateau of exchange bias emerges at the ordering temperature of Tb spins (∼10 K), and we ascribe this unique feature to the strong coupling between Tb and Mn spin sublattices in TbMnO3, which in turn influences the magnetic coupling across the interface. On the other hand, the enhancement of coercivity in La0.7 Sr0.3 MnO 3/TbMnO3 shows monotonous temperature dependence. Our results illustrate a strong interfacial magnetic interaction at the La 0.7 Sr 0.3 MnO3/TbMnO3 interface, highlighting the roles of competing spin orders, magnetic frustration, and coupling between multiple spin sublattices in artificial collinear/noncollinear spin heterostructures. Published version

We report that electrode engineering, particularly tailoring the metal work function, measurement configuration and geometric shape, has significant effects on the bipolar resistive switching (RS) in lateral memory devices based on self-doped SrTiO3 (STO) single crystals. Metals with different work functions (Ti and Pt) and their combinations are used to control the junction transport (either ohmic or Schottky-like). We find that the electric bias is effective in manipulating the concentration of oxygen vacancies at the metal/STO interface, influencing the RS characteristics. Furthermore, we show that the geometric shapes of electrodes (e.g., rectangular, circular, or triangular) affect the electric field distribution at the metal/oxide interface, thus plays an important role in RS. These systematic results suggest that electrode engineering should be deemed as a powerful approach toward controlling and improving the characteristics of RS memories. Published version

We report on the magnetic properties of cuprate/manganite bilayers composed of antiferromagnetic (AFM) La2CuO4 and ferromagnetic La0.70Sr0.30MnO3. The temperature dependent magnetization data indicate an interfacial spin-glass state. Furthermore, the bilayer exhibits significant enhancement of coercivity compared to the La0.70Sr0.30MnO3 single layer and reaches 705 Oe at 5 K. The dependence of coercivity on the AFM layer thickness indicates that the enhancement cannot be explained by the interfacial charge diffusion. Our results suggest that the exchange coupling between Mn and Cu spins and the magnetic frustration at the La2CuO4/La0.70Sr0.30MnO3 interface must be considered to harness the properties of cuprate/manganite heterostructures. Published version

Solid oxide electrolyser cells (SOECs) have been considered effective to produce hydrogen at a high conversion efficiency through high temperature electrolysis (HTE) process and has a potential to scale up to a large-scale economy hydrogen source. The crucial issue for the SOEC moving into practical applications is stability. In this paper, investigation was conducted with the focus on the anode degradation using SOEC cells with strontium doped lanthanum manganite (LSM) anode and strontium doped lanthanum ferro-cobaltites (LSCF) anode. The results showed a more stable performance in LSM cells than LSCF cells when testing at 750ºC anode degradation and anode delamination contributed most of performance drop. The LSM cell is thus more suitable for HTE than the LSCF cell due to its better bonding between the electrolyte and anode.