In this letter, we simulate GNSS/LEO measurements and propose a process strategy for LEO-augmented GNSS medium length baseline RTK. Experiments show that, the performance of GNSS medium length baseline RTK can be sign...
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In this letter, we simulate GNSS/LEO measurements and propose a process strategy for LEO-augmented GNSS medium length baseline RTK. Experiments show that, the performance of GNSS medium length baseline RTK can be significantly improved by introducing LEO satellites. The convergence speed of LEO-augmented GPS or BDS float solution maybe better than GPS/BDS combined under the conditions of similar satellite geometry. Besides, the RMS error of fixed solutions are improved to better than 4 cm from sub-decimeter level.
In recent years, with the swift progression of electric vehicles, new energy storage, intelligent robots and other fields, lithium-ion batteries have been widely used to meet the needs of high energy density, high out...
In recent years, with the swift progression of electric vehicles, new energy storage, intelligent robots and other fields, lithium-ion batteries have been widely used to meet the needs of high energy density, high output voltage and wide operating range of the battery. Typically, lithium-ion batteries operate under complex conditions and are accompanied by physical and chemical changes within them. These factors lead to irreversible physical and chemical changes in lithium-ion batteries, and their potential pitfalls can lead to abnormal system operation and even catastrophic events in electrical systems. Therefore, accurate RUL prediction can effectively indicate thehealth condition of Li-ion battery, and at the same time can ensure the reliability and safety of the system, which is important for the safe operation of the whole Li-ion battery system, and its remaining life assessment has become a research hotspot in the related fields of electrochemistry, intelligent detection and reliability, and has a good development prospect. Therefore, this paper analyzes the common methods and application status of remaining life prediction of lithium-ion batteries, brings together the prediction methods based on model-based methods, data-driven methods and fusion-based methods, and analyzes the advantages and disadvantages of each method to provide reference for relevant technical personnel.
Lithium-ion batteries have become the first choice for electric vehicle power batteries and energy storage power plants due to their good output characteristics and high energy density. Taking the lithium battery as t...
Lithium-ion batteries have become the first choice for electric vehicle power batteries and energy storage power plants due to their good output characteristics and high energy density. Taking the lithium battery as the research object, a battery monomer heat production model is established to explore theheat generation mechanism of the lithium-ion battery, and the simulation results show that the internal temperature field of lithium-ion battery is unevenly distributed, and the middle temperature is higher than the surrounding temperature. The experimental analysis of the thermal runaway characteristics of the lithium-ion battery under the pinning conditions shows that the temperature change trend of the battery is the same at each point during the pinning period, but the temperature at the pinning point is the highest. With the increase of the battery SOC, the maximum temperature at each temperature point increases, but the growth rate of the maximum temperature becomes gradually slower.
Several sets of energetic particle diagnostics, including a set of neutron flux monitoring systems, a solid-state neutral particle analyzer and a fast ion loss probe (FILP), have been used to investigate the energetic...
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Several sets of energetic particle diagnostics, including a set of neutron flux monitoring systems, a solid-state neutral particle analyzer and a fast ion loss probe (FILP), have been used to investigate the energetic ion losses induced by the long-lived saturated internal mode (LLM) in the HL-2A tokamak. Clear experimental evidence for different levels of energetic ion losses induced by LLM, sawtooth and minor disruption has been observed. A numerical calculation for the evolution of neutron emissions was carried out with the FBURN code, and it shows that the neutron emission drop rate linearly increases with the LLM amplitude and no threshold perturbation amplitude exists, illustrating that the loss mechanism for LLM induced energetic ion loss is dominantly convective. In addition, measurement results of the FILP demonstrate that LLM tends to expel energetic ions with relatively low energy (E < 27 keV) and high pitch angle (? > 60(?)), and can suppress the prompt loss of energetic ions with high energy and low pitch angle to a certain degree. Furthermore, the physical process for LLM induced energetic ion loss can be explained by orbit calculations, which show that LLM induced lost energetic ions will transport from center to peripheral region first, and then get lost out of plasma. The experimental observations are successfully reproduced by calculations using the ORBIT code combined with both the NUBEAM code and the MARS-K code. The paper clearly describes the whole physical process of LLM induced energetic ion loss for the first time in the HL-2A tokamak.
Excessive carbon dioxide emissions pose a global environmental issue, and carbon sequestration technology offers a solution. This study proposes a novel approach for carbon dioxide sequestration in the overlying layer...
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