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We investigated the effect of top contact interface and microstructural characteristics of the insulating layers on resistive switching behaviors by fabricating and characterizing the HfO2/ZnO bilayer heterostructures. Different thickness of ZnO underlying layer and different deposition temperatures of the upper HfO2 layer were designed to analyze the intrinsic contribution of the crystalline microstructure of the insulating bilayer. Pt and Ti top electrodes were used to demonstrate the extrinsic contribution of the interface configuration. It was observed that all devices show bipolar RS characteristics. Unlike the device composed of Pt/HfO2/ZnO/Pt that exhibit an abrupt switching, a gradually continuous switching in the reset process was identified in the device composed of Ti/HfO2/ZnO/Pt. Interfacial charge migration process/characteristic plays a key role in the RS process as well as its conduction mechanism. The RS performance of the former is significantly better than that of the latter, including much lower reset voltage, two orders of magnitude larger OFF/ON ratio and HRS resistance. In addition, as compared to the intrinsic contribution arising from the microstructure of the HfO2/ZnO bilayer to the RS performances and current transport mechanism, the extrinsic effect contributed from the electrode characteristics (and its interface) is dominant.

UAV (Unmanned Aerial Vehicle) remote sensing technology plays an increasingly important role in disaster acquisition. At present, after the disaster occurs, the orthophoto images of the UAV in the disaster area can be quickly obtained, but the bidimensionality of the orthophoto image limits the accuracy of disaster information extraction; it is required to improve the timeliness of the large-area 3D model established using the oblique photography technology in the disaster area. Combining the advantages of orthophoto and 3D models, this paper proposes a method for rapid acquisition of disasters based on point-surface combination. The Tibet Milin M6.9 earthquake is used as an example to analyze the advantages and disadvantages of this method in practical applications.

In this article, we have proposed a unique approach to adjust optical bistability (OB) and optical multistability (OM) in a ring cavity inclusive of a three-level quantum system primarily based on quantum mean-field theory. The quantum system interacts with a weak probe light, an incoherent pumping field and a robust coupling light which carries an optical vortex that is an electromagnetic light with optical angular momentum. We confirmed that the real and imaginary parts of the susceptibility of the no-vortex probe light relies on the azimuthal angle and orbital angular momentum (OAM) of the vortex light whilst the quantum interference time period will become important. Moreover, we determined that because of the OAM number of vortex light, the switching from OB to OM is feasible for extraordinary azimuthal angle. These functions of such a three-level quantum system are not stated in any comparable studies.

TiO2is usually employed as a protective layer for Cu2O in photoelectrocatalytic CO2reduction. However, the role of TiO2layer on CO2reduction activity and selectivity is still elusive. In this work, a systematic investigation is carried out to probe the impact of the deposition parameters of TiO2overlayer, including the temperature and thickness, on CO2reduction performance. Compositional and (photo-)electrochemical analysis is performed to explore the property of TiO2overlayers. Carrier behavior, including donor density and electron energy, and stability of TiO2are demonstrated to be influenced by atomic layer deposition conditions and thus play a role in controlling CO2reduction reaction. Specifically, as the thickness of the TiO2layer increases from 2 to 50 nm, the electron energy tends to be lowered accompanying the electron transfer mode from tunneling for TiO2thin layers to type II for thick TiO2, leading to a decrease in CO2reduction selectivity. With an increase of the TiO2deposition temperature, the stability increases with a loss of conductivity. Cu2O coated with 2 nm TiO2at 150 °C is proven to be the optimized candidate in this work for photoelectrochemical reduction of CO2to CO, HCOOH and CH3COOH under an applied bias of -0.4 versus RHE.

The isothermal compression dynamics of ternary Ti-6Al-4V alloy with initial martensitic structures were investigated in the high temperature range 1083–1173 K and moderate strain rate regime 0.01–10 s−1. Shear banding was found to still dominate the deformation mechanism of this process, despite its nonadiabatic feature. The constitutive equation was derived with the aid of Zener–Hollomon parameter, which predicted the apparent activation energy as 534.39 kJ/mol. A combination of higher deformation temperature and lower strain rate suppressed the peak flow stress and promoted the evolution of shear bands. Both experiments and calculations demonstrated that a conspicuous temperature rise up to 83K could be induced by severe plastic deformation. This facilitated the dynamic recrystallization of deformed martensites, as evidenced by the measured microhardness profiles across shear bands.

At present, there are more than 280,000 hidden danger points of geological disasters in China. It has been proved that one of effective ways of reducing geological disasters is using professional equipment to monitor and mobilize the masses. The commonly professional devices include slope radar, crack gauge, laser radar and optical images in early warning period and in rescue phase. Each device has its own unique advantages and we developed a reasonable technical route to achieve the aim that combining the advantages of these various data. The mainly steps: the first step is to process the various data separately; secondly, to fuse the data that can be merged; thirdly, to perform overlay analysis and display on non-integratable data. We takes the high-level landslide of Xinmo Village, Sichuan Province on June 24, 2017 to verify the route’s effective. The results show that the multi-data fusion method can not only achieved the all-round monitoring of key hidden points, but also combined the advantages of multiple data and achieved millimetre-level monitoring accuracy and clear and intuitive effects.

As unmanned aerial vehicle (UAV) remote sensing is applied in small area aerial photogrammetry surveying, disaster monitoring and emergency command, 3D urban construction and other fields, the image processing of UAV has become a hot topic in current research. The precise matching of UAV image is a key problem, which affects the subsequent processing precision directly, such as 3D reconstruction and automatic aerial triangulation, etc. At present, SIFT (Scale Invariant Feature Transform) algorithm proposed by DAVID G. LOWE as the main method is, is widely used in image matching, since its strong stability to image rotation, shift, scaling, and the change of illumination conditions. It has been successfully applied in target recognition, SFM (Structure from Motion), and many other fields. SIFT algorithm needs the colour images to be converted into grayscale images, detects extremum points under different scales and uses neighbourhood pixels to generate descriptor. As we all know that UAV images with rich colour information, the SIFT algorithm improved through combining with the image colour information in this paper, the experiments are conducted from matching efficiency and accuracy compared with the original SIFT algorithm. The results show that the method which proposed in this paper decreases on the efficiency, but is improved on the precision and provides a basis choice for matching method.

Marine gravity field information has a great significance for the resource, environment and military affairs. As a new way to get marine gravity data, the satellite altimetry technique makes up for what ship measuring means lack. The paper carries out the researches on how altimeter data applied for calculating marine gravity anomaly based on inverse Stokes formula. In the article, the editing of 14-track Jason-1 data over South China Sea for 7 years is for collinear processing and cross-point adjustment. The inverse Stokes formula and fast Flourier transform technique are applied to calculate marine gravity anomaly of the region (0°~23°N, 103°~120°E), and to draw gravity anomaly map. Compared with the gravity anomaly by ship observation, RMS is 12.6mGal, and single altimetry satellite has a good precision.

Organic-inorganic hybrid waveguide films doped with disperse red 13 (DR13) were prepared by a low-temperature sol–gel process. The third-order nonlinearity and planar waveguide property of the hybrid films were studied by using z-scan technique under a femtosecond laser pulsed at 800 nm and prism coupling technique. Results indicate that the performance of the third-order nonlinearity in the near ultraviolet region is greatly improved. It is also noted that the as-prepared waveguide films exhibit the properties of low propagation loss and multimode transmission. These results demonstrate that the hybrid planar films might be promising candidates for photonic applications.

We show that it is possible to generate a quadripartite square graph-state entanglement in two-photon resonant systems. Every vertex of the square represents an optical field and every side stands for the entanglement of the two vertices. Four optical fields of different frequencies are coupled to coherently driven three-level ladder atoms. Through such a system, quantum beats and two-photon resonant interactions combine to cause the collective-mode parametric interactions. This results in the collective-mode entanglement, which corresponds to the square graph-state entanglement of the four individual fields.