Search

With the development of blockchain technology, due to the different system architecture and application scenarios of blockchain platforms, it is difficult to realize the interconnection and intercommunication of data and assets on different blockchains, which affects the promotion and application of blockchain. The cross-chain tech-nology of blockchain is an important technical solution to realize the interconnection of blockchain and improve the interoperability and extensibility of blockchain. The blockchain cross-chain protocol is the specific design specifi-cations to realize the cross-chain interoperability between different blockchains through cross-chain technology, so it is of great significance to the realization of blockchain interoperability and the construction of blockchain cross-chain application. This paper systematically arranges and analyzes the latest researches on the integration and implemen-tation of blockchain cross-chain protocols, and places them in four hierarchies: Firstly, the current research status of blockchain cross-chain interoperability is explained from three aspects, Internet of blockchains, cross-chain techno-logy and blockchain interoperability. Secondly, the cross-chain protocols are divided into cross-chain communi-cation agreements, cross-chain asset transaction agreements and cross-chain smart contract call agreements, and the latest research is analyzed. Thirdly, the key design principles of cross-chain protocols are summarized, and the solutions for the problems of security, privacy and scalability of cross-chain protocol are provided. Finally, com-bined with the actual needs of blockchain cross-chain applications, the future research direction of blockchain cross-chain protocol is given.

In this work g-C3N4/CuS composite film was prepared by successive ion layer adsorption and reaction (SILAR) method and used as the counter electrode in quantum dot sensitized solar cell (QDSSCs). To configure the cell, CdSe and CdS quantum dots acted as sensitizers on the photoanode side, polysulphide was used as the electrolyte and copper sulphide was deposited into the g-C3N4 film structure on the counter electrode side. Scanning electron microscope and X-ray diffraction were used to characterize the morphology and structure of the electrode materials, respectively. The photovoltaic performance of the cell was analysed by a standard solar simulator. The results revealed that the photoelectric conversion efficiency of the cell reached 3.65% under condition of AM 1.5 and irradiation intensity of 100mW/cm2.

The effects of precursor powder uniformity on structure and electrical properties of Gd-doped CeO2 (GDC) electrolytes were studied. The as-synthesized GDCx powders (x = 5, 10 and 15 at.%) were calcined at 600 and 1200°C and combined in mass ratios of 100:0 and 95:5 to obtain two precursor powders with different particle size distributions. Sintering of the pressed pellets was performed at 1300 and 1400°C for 10 h. Crystal structure, microstructure and electrical properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and AC impedance spectroscopy, respectively. When a smaller proportion of large particles (calcined at 1200 °C) were present in the precursor powders, sinterability of the prepared samples is slowed down, which had an adverse effect on electrical conductivity. The lower the concentration of Gd, the more significant is the adverse effect. At higher sintering temperature (1400°C), the influence of Gd concentration on microstructure and ionic conductivity is more obvious. The GDC15 sample, prepared from the precursor powder calcined at 600°C, had the highest conductivity and σasGB/σBulk ratio at 300°C.

To address the issue of accuracy in Simultaneous Localization and Mapping (SLAM) for forested areas, a novel point cloud adaptive filtering algorithm is proposed in the paper, based on point cloud data obtained by backpack Light Detection and Ranging (LiDAR). The algorithm employs a K-D tree to construct the spatial position information of the 3D point cloud, deriving a linear model that is the guidance information based on both the original and filtered point cloud data. The parameters of the linear model are determined by minimizing the cost function using an optimization strategy, and a guidance point cloud filter is subsequently constructed based on these parameters. The results demonstrate that, comparing the diameter at breast height (DBH) and tree height before and after filtering with the measured true values, the accuracy of SLAM mapping is significantly improved after filtering. The Mean Absolute Error (MAE) of DBH before and after filtering are 2.20 cm and 1.16 cm; the Root Mean Square Error (RMSE) values are 4.78 cm and 1.40 cm; and the relative RMSE values are 29.30% and 8.59%. For tree height, the MAE before and after filtering are 0.76 m and 0.40 m; the RMSE values are 1.01 m and 0.50 m; the relative RMSE values are 7.33% and 3.65%. The experimental results validate that the proposed adaptive point cloud filtering method based on guided information is an effective point cloud preprocessing method for enhancing the accuracy of SLAM mapping in forested areas. [ABSTRACT FROM AUTHOR]

The diversity of the carrier transport mechanism in the resistive switching process remains a significant obstacle for the design and application of resistive random access memory (RRAM) devices. In this study, the influence of annealing on the dielectric properties of the Ti/HfOx/Pt RRAM device and its associated carrier transport mechanism is investigated. The results reveal that the current conduction in both annealed and unannealed devices is primarily attributed to grain boundary (GB) relaxation, with only the GB acting as a depletion layer that induces dielectric relaxation. Furthermore, annealing decreases the interfacial polarization and changes the relaxation time at the GB. In addition, the charge carriers exhibit nearest‐neighbor hopping conduction at a higher temperature in Ti/HfOx/Pt RRAM devices, whereas variable‐range‐hopping conduction occurs at lower temperatures. Long‐range charge carrier transport also plays a significant role in the conduction process. To offer a deeper understanding of the conduction processes in the Ti/HfOx/Pt RRAM device, a carrier transport model is proposed, which provides valuable insights into the intricate mechanisms governing conduction in these devices. [ABSTRACT FROM AUTHOR]

Supercapacitors often deliver a significantly high-power density with a long cycling life but low energy density. An exceedingly promising approach is to construct asymmetric supercapacitors (ASCs) reconciling the compromise between power density and energy density. However, ASCs combining transition metal oxides (TMOs) and activated carbon (AC) struggle to improve energy density due to a vast difference in their specific capacitance. To cross this hurdle, we first proposed a new strategy to construct the ASCs with α-MoO3 as the anode and conductive polymer polypyrrole (PPy) as the cathode. The remarkable features of α-MoO3, including its layered structure and ultra-high specific capacitance, along with the stability and fast charge–discharge ability of PPy, have contributed significantly to the augmentation of power density and energy density in ASCs. Taking advantage of these bright features, the operation voltage for α-MoO3//PPy is effectively expanded to 2.0 V, exhibiting a high energy density of 25.9 W h kg−1 at 1538 W kg−1. Furthermore, the energy density presented a remarkable recovery rate, reaching 91.04% of its initial state after undergoing full rate tests. These conclusions reveal that the construction of α-MoO3//PPy can effectively enhance the energy density and power density of supercapacitors. [ABSTRACT FROM AUTHOR]

Blockchain provides a new technology for building transmission and trust mechanism of social ralue. The rapid development of blockchain has promoted the deep integration of smart contract with artificial Intelligence, big data and internet of things, so its security has attracted attention. In recent years, researches on security of blockchain and smart contract have made great progress. Thus, based on smart contract on the blockchain, the related works on security of operating mechanism, on-chain smart contract security and off-chain security were classified, analyzed, compared, summarized and discussed. The hot issues of smart contract security in the future were forecasted.