Outbreak of Soybean Aphid in Suihua District in 1998 and its Control Strategies

In 1998, the soybean aphid Aphis glycines Matsumura severely infested soybeans in previously unfested areas and unprecedented damage levels in Suihua District. Damage by soybean aphids caused huge losses. Yield losses in the district were up to 30% on average with a yield reduction of 112.5 million kilograms. The development characteristics, cause and control strategies of soybean aphids in 1998 are presented as follows.Originating text in Chinese.Citation: Sun, Bo, Liang, Shubao, Zhao, Weixia. (2000). Outbreak of Soybean Aphid in Suihua District in 1998 and its Control Strategies. Soybean Bulletin, 8(1), 5-5

Diameter Estimation of Cylindrical Metal Bar Using Wideband Dual-Polarized Ground-Penetrating Radar

Ground-penetrating radar (GPR) has been an effective technology for locating metal bars in civil engineering structures. However, the accurate sizing of subsurface metal bars of small diameters remains a challenging problem for the existing reflection pattern-based method due to the limited resolution of GPR. To address the issue, we propose a reflection power-based method by exploring the relationship between the bar diameter and the maximum power of the bar reflected signal obtained by a wideband dual-polarized GPR, which circumvents the resolution limit of the existing pattern-based method. In the proposed method, the theoretical relationship between the bar diameter and the power ratio of the bar reflected signals acquired by perpendicular and parallel polarized antennas is established via the inherent scattering width of the metal bar and the wideband spectrum of the bar reflected signal. Based on the theoretical relationship, the bar diameter can be estimated using the obtained power ratio in a GPR survey. Simulations and experiments have been conducted with different GPR frequency spectra, subsurface mediums, and metal bars of various diameters and depths to demonstrate the efficacy of the method. Experimental results show that the method achieves high sizing accuracy with errors of less than 10% in different scenarios. With its simple operation and high accuracy, the method can be implemented in real-time in situ examination of subsurface metal bars.Comment: 14 pages, 15 figures, will be published at IEEE Transactions on Instrumentation and Measuremen

A secure cross-domain interaction scheme for blockchain-based intelligent transportation systems

Si, H., Li, W., Wang, Q., Cao, H., Bação, F., & Sun, C. (2023). A secure cross-domain interaction scheme for blockchain-based intelligent transportation systems. PeerJ Computer Science, (November 2023), 1-36. https://doi.org/10.7717/peerj-cs.1678, https://doi.org/10.7717/peerj-cs.1678/supp-1, https://doi.org/10.7717/peerj-cs.1678/supp-2---This work was supported by the Henan Province Key Science-technology Research Project under Grant No. 232102520006 and 232102210122, the Key Research Project of Henan Provincial Higher Education Institution under Grant No. 23A520005, and the Henan Province Major Public Welfare Projects under Grant No. 201300210300. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.In the intelligent transportation system (ITS), secure and efficient data communication among vehicles, road testing equipment, computing nodes, and transportation agencies is important for building a smart city-integrated transportation system. However, the traditional centralized processing approach may face threats in terms of data leakage and trust. The use of distributed, tamper-proof blockchain technology can improve the decentralized storage and security of data in the ITS network. However, the cross-trust domain devices, terminals, and transportation agencies in the heterogeneous blockchain network of the ITS still face great challenges in trusted data communication and interoperability. In this article, we propose a heterogeneous cross-chain interaction mechanism based on relay nodes and identity encryption to solve the problem of data cross-domain interaction between devices and agencies in the ITS. First, we propose the ITS cross-chain communication framework and improve the cross-chain interaction model. The relay nodes are interconnected through libP2P to form a relay node chain, which is used for cross-chain information verification and transmission. Secondly, we propose a relay node secure access scheme based on identity-based encryption to provide reliable identity authentication for relay nodes. Finally, we build a standard cross-chain communication protocol and cross-chain transaction lifecycle for this mechanism. We use Hyperledger Fabric and FISCO BCOS blockchain to design and implement this solution, and verify the feasibility of this cross-chain interaction mechanism. The experimental results show that the mechanism can achieve a stable data cross-chain read throughput of 2,000 transactions per second, which can meet the requirements of secure and efficient cross-chain communication and interaction among heterogeneous blockchains in the ITS, and has high application value.publishersversionpublishe

INTERMITTENT HYPOXIA-INDUCED RENAL ANTIOXIDANTS AND OXIDA- TIVE DAMAGE IN MALE MICE: HORMETIC DOSE RESPONSE

Obstructive sleep apnea causes cardiovascular disease via chronic intermittent hypoxia (IH), which may be related to oxidative stress. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important cellular defense mechanism against oxidative stress by regulating its down-stream multiple antioxidants. The present study was to define whether IH can induce renal pathogenic damage and if so, whether Nrf2 and its down-stream antioxidants are involved in IH-induced pathogenic changes. Mice were culled for exposure to inter- mittent air as control or IH that consisted of 20.9% O2/ 8% O2 FIO2 alternation cycles (30 episodes per h) with 20 seconds at the nadir FIO2 for 12 h a day during daylight. Short term IH exposure (3 – 7 days) induced significant increases in renal inflammatory response and antioxidant levels along with a reduction of the spontaneous content of mal- ondialdehyde while long-term IH exposure (8 weeks) induced a significant decrease of antioxidant levels and significant increases of renal inflammation, oxidative damage, cell death, and fibrosis. This study suggests that IH induces a hormetic response, i.e.: short term IH exposure is able to induce a protective response to protect the kidney from oxidative damage while long-term IH exposure is able to induce a damage effect on the kidney

The Tianlai Cylinder Pathfinder array: System functions and basic performance analysis

The Tianlai Cylinder Pathfinder is a radio interferometer array designed to test techniques for 21 cm intensity mapping in the post-reionization Universe, with the ultimate aim of mapping the large scale structure and measuring cosmological parameters such as the dark energy equation of state. Each of its three parallel cylinder reflectors is oriented in the north-south direction, and the array has a large field of view. As the Earth rotates, the northern sky is observed by drift scanning. The array is located in Hongliuxia, a radio-quiet site in Xinjiang, and saw its first light in September 2016. In this first data analysis paper for the Tianlai cylinder array, we discuss the sub-system qualification tests, and present basic system performance obtained from preliminary analysis of the commissioning observations during 2016-2018. We show typical interferometric visibility data, from which we derive the actual beam profile in the east-west direction and the frequency band-pass response. We describe also the calibration process to determine the complex gains for the array elements, either using bright astronomical point sources, or an artificial on site calibrator source, and discuss the instrument response stability, crucial for transit interferometry. Based on this analysis, we find a system temperature of about 90 K, and we also estimate the sensitivity of the array

Learning to Remove Clutter in Real-World GPR Images Using Hybrid Data

The clutter in the ground-penetrating radar (GPR) radargram disguises or distorts subsurface target responses, which severely affects the accuracy of target detection and identification. Existing clutter removal methods either leave residual clutter or deform target responses when facing complex and irregular clutter in the real-world radargram. To tackle the challenge of clutter removal in real scenarios, a clutter-removal neural network (CR-Net) trained on a large-scale hybrid dataset is presented in this study. The CR-Net integrates residual dense blocks into the U-Net architecture to enhance its capability in clutter suppression and target reflection restoration. The combination of the mean absolute error (MAE) loss and the multi-scale structural similarity (MS-SSIM) loss is used to effectively drive the optimization of the network. To train the proposed CR-Net to remove complex and diverse clutter in real-world radargrams, the first large-scale hybrid dataset named CLT-GPR dataset containing clutter collected by different GPR systems in multiple scenarios is built. The CLT-GPR dataset significantly improves the generalizability of the network to remove clutter in real-world GPR radargrams. Extensive experimental results demonstrate that the CR-Net achieves superior performance over existing methods in removing clutter and restoring target responses in diverse real-world scenarios. Moreover, the CR-Net with its end-to-end design does not require manual parameter tuning, making it highly suitable for automatically producing clutter-free radargrams in GPR applications. The CLT-GPR dataset and the code implemented in the paper can be found at https://haihan-sun.github.io/GPR.html

Excitation device for mining steel wire rope based on magnetic flux leakage detection

The current research does not consider the influence of wire rope swing on the excitation device in the context of engineering applications, resulting in unsatisfactory detection results. In order to solve this problem, a set of mining wire rope excitation devices has been designed. Through the establishment of the wire rope simulation model, the influence of different air gap and lift off value on the magnetic leakage field of wire rope is simulated and studied. It is found that increasing the air gap or lift off value will reduce the magnetic induction intensity of the magnetic leakage field of the wire rope and affect the magnetic leakage detection results of the wire rope. However, in practical applications, the swing amplitude of mining wire ropes is large and the ropes are easy to be polluted. Therefore, the air gap and lift off value of the wire rope excitation device should not be too small. Under the conditions of considering engineering applicability, the air gap is set to 6 mm and the lift off value is set to 5 mm. Further simulation analysis is conducted on the effects of permanent magnet thickness and length, magnetic pole spacing, and armature thickness on the leakage magnetic field of steel wire ropes. It is found that the thickness and length of permanent magnets have the greatest influence on the leakage magnetic field of steel wire ropes. The magnetic pole spacing has a small influence on the leakage magnetic field of steel wire ropes. The influence of armature thickness on the leakage magnetic field of steel wire ropes can be ignored. Based on the simulation results and considering economy and portability, the parameters of the wire rope excitation device are set. The permanent magnet thickness is set to 10 mm, the permanent magnet length is set to 30 mm, the magnetic pole spacing is set to 180 mm, and the armature thickness is set to 10 mm. The dynamic simulation results show that the peak-to-peak value of the magnetic flux density of the wire rope magnetic leakage field reaches 0.9 mT. It indicates that the excitation device can ensure high magnetic leakage at the damage. The experimental results show that the magnetic flux leakage signal shows significant fluctuations at different broken wire locations of the steel wire rope. It indicates that the excitation device has a good excitation effect and can accurately detect broken wire damage of the steel wire rope

Estimating the diameter of reinforcing bars using an ultra-wideband MIMO GPR array

Ground-penetrating radar (GPR) is an effective non-destructive detection technology for locating and characterizing reinforcing bars in concrete structures. However, the accurate quantification of reinforcing bar diameters, especially in small-diameter cases, remains a challenging issue. In this paper, a sizing method based on multiple-input-multiple-output (MIMO) GPR arrays is presented to estimate the reinforcing bar diameter in concrete. The method employs a linear array of ultra-wideband (UWB) antennas to acquire the full-matrix MIMO data of the reinforcing bar embedded in concrete. The diffraction stacking algorithm is applied to the obtained MIMO data to reconstruct the reinforcing bar. The 3 decibels (dB) drop technique is used to measure the chord length that passes through the peak intensity point of the reconstruction image of the reinforcing bar. Following that, the diameter of the reinforcing bar can be determined based on its cover depth and the chord length. Extensive numerical studies and experiments have been conducted to examine the performance of the proposed method in different scenarios. The method shows excellent sizing accuracy for reinforcing bars with different diameters and cover depths.Agency for Science, Technology and Research (A*STAR)The authors acknowledge funding from A*STAR Science and Engineering Research Council, Singapore under AME Individual Research Grant (IRG) 2018 Grant Call (Project No. A1983c0030)