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Fluoride-salt-cooled High-temperature Reactor (FHR) is a promising nuclear reactor technology. Among many challenges presented by the molten fluoride salts is the corrosion of salt-facing structural components. Higher moisture contents, in the FLiNaK (LiF-NaF-KF, 46.5–11.5-42 mol%) salt, aggravate intergranular corrosion and pitting for the given alloys. Therefore, several thermal dehydration tests of FLiNaK salt were performed with a batch size suitable for thermal-hydraulic experiments. Thermogravimetric Analysis (TGA) was performed for the three constituent fluoride salts individually. Preliminary thermal dehydration plans were then proposed for NaF and KF salts based on the TGA curves. However, the dehydration process may not be required for LiF since its low mass loss (500 °C) were necessary to remove a significant amount of moisture (>1 wt%) from NaF salt, while relatively low temperatures (around 300 °C) with a long holding time (>10 h) were sufficient to remove most of the moisture from KF salt.

In order to reduce costs and environmental hazards, this article explores a new synthesis method for preparing NaY zeolite using water quenching residue as the raw material. The effects of the crystallisation time, crystallisation temperature, n(SiO₂)/n(Al₂O₃) ratio and n(Na₂O)/n(Al₂O₃) ratio on the crystallisation of NaY zeolite were investigated, and an ideal synthetic route was obtained. The physical and chemical properties of the prepared NaY zeolite were characterised by XRD, SEM, STEM, FTIR and other methods. In order to understand the adsorption performance of the prepared Y zeolite, different adsorption isotherm models were studied at 30 °C, 60 °C, 90 °C and 0 to 1 bar. At these three temperatures, NaY zeolite has a much higher adsorption capacity for CO₂ than N₂. The Toth equation fits well the CO₂ adsorption of NaY zeolite. The BET test calculates that the micropore specific surface area of NaY zeolite is 838.88m²/g. The range of the zeolite micropores is mainly between 0.35∼0.45nm. The NaY zeolite obtained by the technical route reported in this study has high crystallinity, a uniform particle size, high thermal stability, and excellent CO₂ adsorption performance under flue gas conditions, and will have potential applications in the CO₂ capture in steel plant flue gas prospect

In recent years, with the increasing consumption of resources around the world, motors in various industries are also urgently added to the ranks of energy saving and emission reduction. High-speed permanent magnet air compressor is widely used in various new energy vehicles. The study on its loss can provide reference for motor manufacturing industry. In this paper, the 27 kW, 90000 r/min high-speed permanent magnet air compressor is studied and analyzed. Taking 0.1 mm thick silicon steel sheet as an example, two different kinds of silicon steel sheet materials were compared and analyzed through the study of stator core loss. At the beginning of the design of the motor, the material was tested, and the good performance, low carbon and environmentally friendly material was used in the design and manufacture of the motor, which played a good role in the stable operation of energy saving and emission reduction and the motor. The high-speed motor uses frequency converter for power supply, and its characteristics of large harmonic content and high frequency lead to the increase of rotor eddy current loss. Therefore, the analytical calculation method of rotor eddy current loss is derived. This method establishes the physical model in polar coordinate system, and considers the sub domains such as air gap, sheath and permanent magnet. A prototype and an experimental platform were made to study the influence of harmonics on the motor. In this paper, the actual output current harmonics with IGBT and SIC as controllers are studied by comparative method. The actual output current is collected and applied as excitation to the 2D finite element model of motor for analysis and calculation. Finally, the influence of motor loss is analyzed comprehensively, which has reference value for each motor manufacturing enterprise.

Phycobilisomes and chlorophyll-a (Chla) play important roles in the photosynthetic physiology of red macroalgae and serve as the primary light-harvesting antennae and reaction center for photosystem II. Neopyropia is an economically important red macroalga widely cultivated in East Asian countries. The contents and ratios of 3 main phycobiliproteins and Chla are visible traits to evaluate its commercial quality. The traditional analytical methods used for measuring these components have several limitations. Therefore, a high-throughput, nondestructive, optical method based on hyperspectral imaging technology was developed for phenotyping the pigments phycoerythrin (PE), phycocyanin (PC), allophycocyanin (APC), and Chla in Neopyropia thalli in this study. The average spectra from the region of interest were collected at wavelengths ranging from 400 to 1000 nm using a hyperspectral camera. Following different preprocessing methods, 2 machine learning methods, partial least squares regression (PLSR) and support vector machine regression (SVR), were performed to establish the best prediction models for PE, PC, APC, and Chla contents. The prediction results showed that the PLSR model performed the best for PE (RTest2 = 0.96, MAPE = 8.31%, RPD = 5.21) and the SVR model performed the best for PC (RTest2 = 0.94, MAPE = 7.18%, RPD = 4.16) and APC (RTest2 = 0.84, MAPE = 18.25%, RPD = 2.53). Two models (PLSR and SVR) performed almost the same for Chla (PLSR: RTest2 = 0.92, MAPE = 12.77%, RPD = 3.61; SVR: RTest2 = 0.93, MAPE = 13.51%, RPD =3.60). Further validation of the optimal models was performed using field-collected samples, and the result demonstrated satisfactory robustness and accuracy. The distribution of PE, PC, APC, and Chla contents within a thallus was visualized according to the optimal prediction models. The results showed that hyperspectral imaging technology was effective for fast, accurate, and noninvasive phenotyping of the PE, PC, APC, and Chla contents of Neopyropia in situ. This could benefit the efficiency of macroalgae breeding, phenomics research, and other related applications.

The ultra-high speed permanent magnet motor (UHSPM) for hydrogen fuel cell air compressor is characterized by high speed, high motor power density, small size, and high reliability. Compared to the conventional motor, the loss per unit volume is increased and therefore the calculation of the temperature field is more important than that of conventional motors. In this paper, a UHSPM with a rated speed of 90000 r/min is designed. Firstly, a finite element (FE) model of the UHSPM is established and the losses of each part of the high-speed motor are calculated, and the calculated losses are introduced into the fluid field in the form of a heat source for motor temperature analysis. The calculated losses were introduced into the fluid field in the form of a heat source and used in the motor temperature analysis. The temperature rise was then calculated for the unidirectional and bidirectional magneto-thermal coupling (MTC) respectively. The results show that the bidirectional magneto- thermal coupling (BMTC) simulation results are about 2-3°C smaller than the experimental measured values, which can more accurately predict the motor temperature. The measurement results verify the accuracy of BMTC, and provide basic theoretical support for the subsequent cooling optimization scheme of high-speed motor.

Abstract Background Pyropia is an economically advantageous genus of red macroalgae, which has been cultivated in the coastal areas of East Asia for over 300 years. Realizing estimation of macroalgae biomass in a high-throughput way would great benefit their cultivation management and research on breeding and phenomics. However, the conventional method is labour-intensive, time-consuming, manually destructive, and prone to human error. Nowadays, high-throughput phenotyping using unmanned aerial vehicle (UAV)-based spectral imaging is widely used for terrestrial crops, grassland, and forest, but no such application in marine aquaculture has been reported. Results In this study, multispectral images of cultivated Pyropia yezoensis were taken using a UAV system in the north of Haizhou Bay in the midwestern coast of Yellow Sea. The exposure period of P. yezoensis was utilized to prevent the significant shielding effect of seawater on the reflectance spectrum. The vegetation indices of normalized difference vegetation index (NDVI), ratio vegetation index (RVI), difference vegetation index (DVI) and normalized difference of red edge (NDRE) were derived and indicated no significant difference between the time that P. yezoensis was completely exposed to the air and 1 h later. The regression models of the vegetation indices and P. yezoensis biomass per unit area were established and validated. The quadratic model of DVI (Biomass = − 5.550DVI2 + 105.410DVI + 7.530) showed more accuracy than the other index or indices combination, with the highest coefficient of determination (R2), root mean square error (RMSE), and relative estimated accuracy (Ac) values of 0.925, 8.06, and 74.93%, respectively. The regression model was further validated by consistently predicting the biomass with a high R2 value of 0.918, RMSE of 8.80, and Ac of 82.25%. Conclusions This study suggests that the biomass of Pyropia can be effectively estimated using UAV-based spectral imaging with high accuracy and consistency. It also implied that multispectral aerial imaging is potential to assist digital management and phenomics research on cultivated macroalgae in a high-throughput way.

In view of the uncertainty and volatility of wind power generation and the inability to provide stable and continuous power, this paper proposes a hydrogen storage wind-gas complementary power generation system, using Matlab/Simulink to simulate and model wind generators and gas turbines. Considering the economy and power supply reliability of the wind-gas complementary power generation system, and taking the economic and environmental cost of the system as the objective function, the capacity optimization model of the wind-gas complementary power generation system is established. The brain storming algorithm (BSO) is used to solve the optimization problem, and the BSO algorithm is used to optimize the BP neural network, which improves the accuracy of the BP neural network for load forecasting. Finally, a simulation is carried out with load data in a certain area, and the simulation verification verifies that BSO-BP can improve the accuracy of load forecasting and reduce the error of load forecasting. Multi-objective optimization of system economic cost and environmental cost through BSO algorithm can make the system cost reach the most reasonable level. Through the analysis of the calculation examples, it is verified that gas-fired power generation can effectively alleviate the volatility of wind power generation, showing the role and advantages of energy complementary power generation. Therefore, the wind-gas complementary system can effectively increase energy utilization and reduce wind curtailment.

The behavior of two-phase flow and corresponding flow regimes in helical tubes significantly differ when compared to two-phase flows in straight tubes due to centrifugal and torsion effects. In order to gain physical insight and gather data for validating computational models, a large number of experiments were performed on a helical coil experimental setup operated with a mixture of water and air. The experimental data were used to assess the predictive capabilities of current two-phase Computational Fluid Dynamics (CFD) models based on the Volume of Fluid (VOF) approach. In the present paper, a comparison of the CFD simulation results with the high-resolution experimental data is discussed, with special emphasis on two-phase pressure drops and void fraction distributions. It is shown that the CFD VOF model is able to correctly capture the occurrence of five flow regimes observed in the experiments, namely bubbly flow, plug flow, slug flow, slug-annular flow, and annular flow. However, a good quantitative agreement for pressure drops and void fraction distributions is found in slug flow and slug-annular flow regimes only. The good agreement found only in a limited range of flow regimes demonstrates that there is not a single set of best-practice guidelines for CFD VOF models that can be applied across a wide range of two-phase flow regimes. Also, there is not a single mesh that can be used to simulate all of the flow regimes and a case-specific mesh and time-step convergence study is needed for each individual flow regime. In the current study, optimal mesh size and time step were obtained for a slug flow test case. Hence, good agreement was obtained only for similar flow regimes, leading to significant disagreement with experimental data for test cases with substantially different flow patterns.

The pre-pressure device of the ultrasonic motor plays a vital role in the design of the entire motor structure, the contact state of the stator and rotor of the motor, dynamic properties of the stator, friction and wear characteristics of the rotor; even the mechanical behaviors of the entire electric machinery have a profound impact. Appropriate pre-pressure is conducive to the smooth operation of the ultrasonic motor, so that the output performance remains excellent, reducing wear and effectively extend the service life of the motor. Therefore, the research on pre-stress is of great significance, as it can better optimize the structure of the three-stator ultrasonic motor and lay the foundation for the stable operation of the motor. First, this paper introduces the construction of the motor as a whole and the pre-pressure device briefly described the working mechanism of the motor, and then introduces the influence of the pre-pressure on the stator and rotor contact models, the position of the constant velocity point, and the modal frequency. Finally, the motor output under different pre-pressures is discussed. The performance experiment has determined the optimal pre-pressure interval, which provides help for its subsequent optimization.

With the development of intelligent and integrated electronic devices, leadless integrated sensors have a broad development. One of the most critical processes in TSV (Through Silicon Via) leadless packaging is Au–Au bonding, which the bond strength determines the success or failure of sensor preparation. In this research, the effect of the bonding temperature on the bonding strength was studied for the designed the temperature and pressure integrated sensor. To further increase the bonding strength, plasma treatment of the metal surface was applied. The influence of various plasma atmospheres and treatment times on the surface morphology, surface hydrophilicity, chemical state and the bonding rate were studied. And bonding interfaces under different bonding conditions were characterized. Finally, after 120 s of O2 plasma treatment and bonding for 1 h at 450 °C and 4000 mbar, the bond strength was increased by 68%, reaching 27 MPa, which enhances the feasibility of the preparation of temperature and pressure integrated sensors.

Abstract Background Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the leading chronic liver disease globally, and there are no approved pharmacotherapies to treat this disease. Ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1) has been found to be related to insulin resistance and lipid accumulation. However, the role and mechanism of Enpp1 in the development of MAFLD remain unknown. Results Here we discovered that Enpp1 is lowly expressed in the liver of MAFLD patients by clinical investigation. Knocking out Enpp1 in the liver of mice aggravated obesity, insulin resistance and hepatic steatosis, and these effects were reversed by liver-specific Enpp1 overexpression. Through transcriptomic data mining and experimental validation, we demonstrated that Enpp1 deficiency inhibited the expression of AMPK (energy receptor) and PPARα (nuclear transcription factor for lipid metabolism), thereby promoting the transcription of lipid synthesis factors and mediating the progression of MAFLD. Mechanistically, Enpp1 enhanced the activity of AMPK by increasing the AMP-to-ATP ratio, which in turn raised PPARα levels and promoted the transcription of its downstream lipid metabolism factors. Pharmacological inhibition of AMPK activity abolished the promoting effect of Enpp1 on PPARα protein expression. Conclusions This study indicate that Enpp1 can effectively ameliorate MAFLD through effects on AMPK/PPARα signaling pathway-mediated lipid metabolism, revealing the significance of Enpp1 as a promising therapeutic target against MAFLD.

The study explores the relationship between subway passenger satisfaction and passenger travel behaviour characteristics from the perspective of subway passengers. This study takes Qingdao as an example and designs a questionnaire that includes the basic personal information and travel behaviour characteristics of passengers and evaluates their subway satisfaction. A total of 6340 valid questionnaires were obtained through the combination of online surveys and on-site random surveys. By using the fuzzy synthetic evaluation, the overall score of passenger satisfaction with the Qingdao subway is determined. According to the relationship between passenger satisfaction and travel behaviour characteristics, the chi-square test is used to select the correlation variables group. The results show that there is no significant correlation among the satisfaction of subway passengers, the main means of transportation and the availability of private cars; the frequency of taking the subway is related to the satisfaction of subway passengers; and the purpose of travelling and the reasons for choosing the subway are significantly related to the satisfaction of subway passengers. Finally, based on the analysis of the differences in satisfaction under different conditions, some suggestions were proposed to improve the satisfaction of subway passengers.

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions. Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2 agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice. After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.

Tendon injury is a common and challenging problem in the motor system that lacks an effective treatment, affecting daily activities and lowering the quality of life. Limited tendon regenerative capability and immune microenvironment dyshomeostasis are considered the leading causes hindering tendon repair. The chirality of biomaterials was proved to dictate immune microenvironment and dramatically affect tissue repair. Herein, chiral hierarchical structure hydroxylapatite (CHAP) nanoplates are innovatively synthesized for immunomodulatory purposes and further coated onto polylactic acid electrospinning membranes to achieve long-term release for tendon regeneration adaption. Notably, levorotatory-chiral HAP (L-CHAP) nanoplates rather than dextral-chiral or racemic-chiral exhibit good biocompatibility and bioactivity. In vitro experiments demonstrate that L-CHAP induces macrophage M2 polarization by enhancing macrophage efferocytosis, which alleviates inflammatory damage to tendon stem cells (TDSCs) through downregulated IL-17-NF-κB signaling. Meanwhile, L-CHAP-mediated macrophage efferocytosis also promotes TDSCs proliferation and tenogenic differentiation. By establishing a rat model of Achilles tendon injury, L-CHAP was demonstrated to comprehensively promoting tendon repair by enhancing macrophage efferocytosis and M2 polarization in vivo, finally leading to improvement of tendon ultrastructural and mechanical properties and motor function. This novel strategy highlights the role of L-CHAP in tendon repair and thus provides a promising therapeutic strategy for tendon injury.