To address the issues of slow magnetization current tracking speed, prolonged magnetization time, and low accuracy during magnetic particle testing of ship castings, forgings, and welded components, this study designed a high-precision rapid current tracking control system. By integrating the predictive characteristics of the Newton interpolation algorithm with the robustness of PID control, a compound control algorithm with a pre-judgment mechanism was developed. An innovative three-phase zero-crossing detection circuit architecture was also implemented, combining high-speed A/D converters and CS5460 chips to optimize current tracking methods, resolving the conflict between initial tracking phase deviation and dynamic process overshoot in conventional approaches. Experimental results demonstrated that this method significantly improves magnetization speed, achieving target current tracking within 0.5 seconds with errors below 2%, meeting the design requirements for non-destructive testing in ship welding applications.
Chlorine is a crucial radionuclide that must be removed in irradiated nuclear graphite. Understanding the interaction between chlorine and graphene-based materials is essential for studying the removal process of 36Cl from irradiated nuclear graphite. In this study, first-principle density functional theory (DFT) was utilized to investigate the adsorption characteristic of chlorine on the original and reconstructed edges of graphene-based materials. Based on the calculation of adsorption energy of the structures after each step of adsorption, the most energetically favorable adsorption routes at four types of edge were determined: Along the armchair edge and reconstructed zigzag edge, the following adatoms would be adsorbed to compensate the distortion induced by the previously adsorbed atom. Meanwhile at the original zigzag edge, chlorine atoms would be adsorbed alternatively along the edge to minimize the repulsion between two adjacent chlorine atoms. The chemical nature of the bonds formed as a result of adsorption was elucidated through an examination of the density of states (DOS) for the two adsorbed chlorine atoms and the carbon atoms attached. Furthermore, to assess the relative stability of the adsorption structures, formation energy of all energetically favorable structures following adsorption was computed. Consequently, the predominant adsorption structure was identified as the reconstructed armchair edge with two chlorine atoms adsorbed. The desorption process of 36Cl2 from the predominant structure following adsorption was simulated, revealing an energy barrier of 1.14 V for desorption. Comparison with experimental results suggests that the chlorine removed from reconstructed armchair edges significantly contributes to the low-temperature removal stage of 36Cl from irradiated nuclear graphite.
In this paper, the formation and characterization of Pt2, Pt3 as well as Pt4 atomic clusters in cup-stacked carbon nanotubes (CSCNTs) are evaluated by DFT to examine the adsorption capacity under the clusters. The results show that the Pt clusters move toward the bottom edge or form rings in the optimized stable structure. Pt far from the carbon substrate possesses more active electrons and adsorption advantages. The three clusters can adsorb up to 17, 18, and 16 hydrogen molecules. Loading metal clusters at the bottom edge maintains a relatively good adsorption property despite the low binding energy through comparative studies. The adsorption capacity does not increase with the number of Pt for metal aggregation reducing the hydrogen adsorption area thus impacting the hydrogen storage ability and the aggregation phenomenon limiting the action of Pt metal. During adsorption, chemisorption occurs only in the Pt2 cluster, while multiple hydrogen molecules achieve physiochemical adsorption in the Pt3 and Pt4 clusters. Compared with the atomic loading of the dispersion system in equal quantities, the dispersion system features higher molecular stability and can significantly reduce the energy of the carbon substrates, providing more sites for hydrogen adsorption in space.
A phenylboric acid functionalized carbon dot (2-FPBA-CD) for rapid fluorescent sensing of glucose in blood was synthesized by simply mixing N, S-doped carbon dots (CDs) with phenylboric acid at room temperature. At pH 7.4, the response of 2-FPBA-CD to glucose could reach equilibrium in a very short time (10 min), with a wide responsive linear range of 19.70 μM to 2.54 mM, which can be applied to the detection of glucose in serum. The mechanism studies showed that the layered carbon film of 2-FPBA-CD aggregated after adding glucose, thereby leading to the fluorescence quenching of 2-FPBA-CD.
This scholarly investigation delves into the legal complexities arising from the People’s Republic of China’s high-altitude balloons entering US airspace. By analyzing landmark cases, such as the Lockerbie incident, this study emphasizes the urgent need for clear liability norms in international airspace. The 2023 Montana Incursion served to clarify the self-defense and proportionality principles under international law. This study examines the nature of these balloons to determine whether they fall under international accords such as the Chicago Convention. It also explores military classifications and legal ambiguities surrounding non-combatant operators in armed conflicts. This paper identifies gaps in the principles of privacy and ethics concerning intelligence gathering within sovereign boundaries. It advocates for new multilateral treaties with geofencing standards to regulate high-altitude unmanned aerial vehicles. This author aims to fortify legal frameworks based on technological advances.
With the increasing value of data and the growing power in the field of digital economy, China has taken the governance of cross-border data flow(CBDF) as an important national strategy. At the domestic policy level, China has piloted Beijing, Shanghai, Hainan and Xiongan New Area to create international data centers with the intention to control inbound and outbound data resources. At the domestic legislative level, China insists that the outbound data transfers be conducted in a secure environment. At the international cooperation level, on the basis of the Global Data Security Initiative, China builds the consensus of countries and promotes cooperation among countries along the Belt and Road routes on CBDF through the Digital Silk Road. Simultaneously, China will engage proactively in the newly international economic and trade agreements, with RCEP standing as a prime example. China’s discourse and model on CBDF governance have been continuously enhanced.