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Summary: Cold plasma (CP) is a promising technology for fresh‐cut fruits and vegetables. In this study, the effects of CP on postharvest senescence, especially from the perspective of oxidative response of fresh‐cut bamboo shoots were examined, including the colour, firmness, lignin content, reactive oxygen species (ROS) accumulation and antioxidant enzymatic activities. CP treatments delayed the browning of bamboo shoots indicating by the increase of L* and b* values and decrease of a* value. The browning inhibition coincided with the reduction of PPO activities up to 62% by CP at 20 kV. Cellulose and lignin accumulated during storage. CP at 30 kV accelerated lignification, whereas CP at 10 and 20 kV inhibited the increase. These results were also reflected by PAL, CAD and POD activities that were enhanced by CP at 30 kV and inhibited by CP at 10 and 20 kV. The content of O2− and H2O2 was significantly increased at the first 3 days and decreased afterwards, with a similar trend of antioxidant enzymes SOD and CAT. As smaller increases in H2O2 and O2− production in CP treated samples than in control were probably attributed to elevated CP‐induced SOD activity. In addition, there was a delay effect observed in the internal parts of bamboo shoots compared with the surface (<5 mm thick). CP extended the shelf‐life of bamboo shoots by triggering the antioxidant defence. CP at 20 kV exhibited the best preservative effect on fresh‐cut bamboo shoots. [ABSTRACT FROM AUTHOR]

Background: Causal mediation analysis plays a crucial role in examining causal effects and causal mechanisms. Yet, limited work has taken into consideration the use of sampling weights in causal mediation analysis. In this study, we compared different strategies of incorporating sampling weights into causal mediation analysis. Methods: We conducted a simulation study to assess 4 different sampling weighting strategies-1) not using sampling weights, 2) incorporating sampling weights into mediation "cross-world" weights, 3) using sampling weights when estimating the outcome model, and 4) using sampling weights in both stages. We generated 8 simulated population scenarios comprising an exposure (A), an outcome (Y), a mediator (M), and six covariates (C), all of which were binary. The data were generated so that the true model of A given C and the true model of A given M and C were both logit models. We crossed these 8 population scenarios with 4 different sampling methods to obtain 32 total simulation conditions. For each simulation condition, we assessed the performance of 4 sampling weighting strategies when calculating sample-based estimates of the total, direct, and indirect effects. We also applied the four sampling weighting strategies to a case study using data from the National Survey on Drug Use and Health (NSDUH). Results: Using sampling weights in both stages (mediation weight estimation and outcome models) had the lowest bias under most simulation conditions examined. Using sampling weights in only one stage led to greater bias for multiple simulation conditions. Discussion: Using sampling weights in both stages is an effective approach to reduce bias in causal mediation analyses under a variety of conditions regarding the structure of the population data and sampling methods. [ABSTRACT FROM AUTHOR]

Bedridden elderly need to be repositioned at regular intervals to prevent pressure ulcers. However, repositioning, being one of the most physically demanding tasks in nursing, faces many challenges, including work-related injuries and limited manpower. To address these problems, we have developed a multifunctional nursing bed system. This system not only assists in repositioning and transitioning positions but also features in-bed position recognition, enabling automatic repositioning based on recognition results. In this paper, the repositioning process was analysed, and the nursing bed mechanism and its control design were developed. An algorithmic framework for in-bed position recognition, including preprocessing and convolutional neural networks, is proposed. The experimental results demonstrate that the nursing bed system facilitates comfortable repositioning and position transition for subjects. In a short-term experiment, the system demonstrated an accuracy rate of 96.83% for in-bed position recognition. Meanwhile, in a long-term experiment, it achieved a success rate of 93.89% for automatic repositioning. These findings indicate that the proposed system demonstrates substantial potential in nursing care, particularly in pressure ulcer prevention. [ABSTRACT FROM AUTHOR]

In this study, the influence laws of different parameters on the exclusion characteristics of hailstone and ice flake, and on the aerodynamic performance of the inlet are studied by numerical method. The motion of the hailstone and ice flake is simulated using the 6-DOF method. Results show that the inhalation of hailstone in the inlet decreases total pressure distortion by about 20%, and the total pressure recovery coefficient is essentially unchanged. Icing of the upper lip decreases the total pressure distortion of the inlet by about 22%, and the total pressure recovery coefficient decreases by 0.6%. The ice flakes on the inner and outer lip, when shed and brake by collision with the center body, will cause damage to the engine duct. The shedding and breaking of ice flake at an angle of 150° to the lip can result in a large amount of ice flake debris entering the engine duct, threatening the performance and structure of the engine in the rear. The motion characteristics of hailstone and ice flake under helicopter fuselage/rotor/inlet integration conditions are revealed. It also provides a reference on the numerical methods for the numerical study of hailstone/ice flake exclusion characteristics of helicopter fuselage/rotor/inlet integration conditions. [ABSTRACT FROM AUTHOR]

Water pollution is becoming more and more serious nowadays, and water resources are in shortage. As an environmentally friendly wastewater treatment technology without secondary pollution, the three-dimensional electrode method has received more and more attention. However, the conventional direct current (DC) three-dimensional electrode method has the disadvantages of high energy consumption and low current efficiency. Based on this, this work investigated the treatment of malachite green (MG) dye wastewater by pulse three-dimensional electrode method. The influences of pulse duty cycle, pulse period, electrolysis voltage, initial pH, aeration rate and Na2SO4 concentration on MG degradation were investigated. The results showed that under the optimal operating conditions of pulse duty cycle of 0.4, pulse period of 15 s, electrolysis voltage of 15 V, initial pH of 5, aeration rate of 0.5 L/min, Na2SO4 concentration of 0.10 mol/L, the removal rates of MG and COD reached 96.2% and 80.5%, respectively, the current efficiency reached 93.4%, and the energy consumption was 24.2 kWh/kg COD after 150 min. Compared with DC power supply mode, the MG removal rate, COD removal rate and current efficiency were enhanced, and the energy consumption was reduced by 83.9%. Moreover, the generation capacity of ·OH was increased under pulse power supply mode. Finally, a possible degradation pathway of MG in pulse power supply mode was inferred using UV-vis and GC-MS analysis. This study indicates that the pulse three-dimensional electrode method is an efficient and low-energy-consumption wastewater treatment method with stable degradation performance for MG dye wastewater. [ABSTRACT FROM AUTHOR]

Phosphogypsum, which contains toxic components (e.g., heavy metal elements and fluoride), is one of the byproducts of phosphoric acid production, and filling subgrade is one of the recycling methods for it. In this study, phosphogypsum was stabilized by lime to improve the mechanical properties [California bearing ratio (CBR), resilience modulus, unconfined compressive strength, and shear strength], water stability, and harmful substances dissolubility. Combined with scanning electron microscopy, the strength formation and water stability enhancement mechanism of lime-stabilized phosphogypsum (LSP) were explored. The results demonstrated that the mechanical properties of LSP were better with the lime content of 6%–10%. The CBR, resilience modulus, unconfined compressive strength, and shear strength were 3.35 times, 2.46 times, 8.61 times, and 1.39 times that of plain phosphogypsum, respectively. An intensity prediction model with a correlation of 97% was constructed. The CBR and resilience modulus softening coefficient of LSP reached best values when lime content was 6%–8%. The leaching concentration of arsenic, chromium, and lead of LSP with 2% lime met the quality standards of groundwater levels I, II, and IV, respectively. Fluoride and phosphate were not detected in LSP when lime content was greater than 6.0%. The results show that LSP is feasible as subgrade filler. Considering the mechanical properties, water stability, and dissolution of hazardous substances of LSP, it is recommended to add 6%–8% lime content to LSP as highway subgrade filler. [ABSTRACT FROM AUTHOR]

Herein we synthesized biochar/iron oxide composite (C/α‐Fe2O3/γ‐Fe2O3) by two‐step calcination method. The prepared C/α‐Fe2O3/γ‐Fe2O3 had a highly pure and a concentration ratio of α‐Fe2O3 and γ‐Fe2O3 about 1 : 1. The optical properties of as‐synthesized C/α‐Fe2O3/γ‐Fe2O3 show a lower bandgap energy (1.90 eV) than that of pure C/α‐Fe2O3 (2.02 eV). The effects of different biochar composite catalysts on the removal of amino black were investigated. Upon illumination, the total removal rate of amino black dye by C/α‐Fe2O3/γ‐Fe2O3 catalyst reached 98 %, which was about 1.7 times that of C/α‐Fe2O3. In addition, the coercivity and the remanence intensity of C/α‐Fe2O3/γ‐Fe2O3 is respectively 1.81 times and 7.17 times that of C/α‐Fe2O3. The catalyst could be magnetically separated and reused for five times with a slight loss of its reactivity. The study of biochar composite provides a new direction for the removal of toxic organic dye in wastewater. [ABSTRACT FROM AUTHOR]

To address the problem that there are many limestone particle decomposition reaction models and it is difficult to accurately select the appropriate one, this paper established two typical one-dimensional unsteady numerical calculation models for single-particle limestone decomposition, coupling the convective heat transfer, thermal conduction, and CO2 mass transfer processes. Two numerical calculation models were solved through the Matlab R2021a platform, and the internal temperature, CO2 concentration distribution, and decomposition reaction rate of the limestone particles during the period from the beginning of temperature rise to the end of decomposition were obtained. Compared with the experimental data, Model 1 has a better agreement with a relative error of less than 10%. The simulation results have shown that the average decomposition reaction rate is 20% higher than the average mass transfer rate. As the particle size increases from 20 mm to 80 mm, the time required for temperature rise in the initial stage changes from 6.6 min to 42.7 min. It is noted that the CO2 volume fraction increment increases by 0.42% with a particle size of 80 mm and a heating temperature of 1050 °C, indicating that the influence of the distribution of CO2 on the limestone decomposition may not be ignored. [ABSTRACT FROM AUTHOR]

Homography estimation serves an important role in many computer vision tasks. Depending heavily on hand‐craft feature quality, traditional methods degenerate sharply in scenes with low texture. Existing deep homography methods can handle the low‐texture problem but are not robust for scenes with low overlap rates and/or illumination changes. This paper proposes a novel unsupervised homography estimation method that can simultaneously handle such low overlap and illumination change. Specifically, a powerful module, named global transformer contextual encoder (GTCE) is first designed, together with a correlation encoder to effectively aggregate global contextual information and reduce matching ambiguity between feature maps. Moreover, a hybrid photo‐perceptual loss for unsupervised homography estimation is proposed. The proposed loss function considers alignment information on both pixel level and perceptual level thus helping this network to be more adaptive to various scenes, including normal cases and illumination change cases. The results of extensive experiments on synthetic and real‐world datasets demonstrate the superiority of this proposed method over current state‐of‐the‐art solutions especially on challenging scenes with low overlap rates, repetitive patterns and illumination changes. [ABSTRACT FROM AUTHOR]

In this paper, a unique hydrolysis reaction process for the production of 4‐Aminoantipyrine (AA) is investigated. A liquid‐phase analytical method for AA is established, and the amount of sulfuric acid, reaction temperature, reaction time are studied. On the basis of single factor experiments, the response surface method (RSM) is used to systematically optimize the conditions of the hydrolysis reaction. The optimum conditions are n(AT‐SO4): n(H2SO4)=0.73, the reaction temperature is 98 °C, the reaction time is 91 min, and the AA yield reaches 90.80 %. Compared with the previous process, the yield of AA is improved and colloids are significantly reduced. Under optimum process conditions, a kinetic model is constructed in the range of 358 K–373 K, which activation energy, Ea=33.21 kJ/mol, and the pre‐exponential factor, A=1586.84. In addition, the product AA is characterized by IR analysis, LC‐MS analysis, GC‐MS analysis and hydrolysis reaction mechanism are investigated. [ABSTRACT FROM AUTHOR]

In this paper, a unique process for the production of methyl anthranilate (MA) was investigated. The factors of the phthalimide/sodium hypochlorite/methanol molar ratio, reaction temperature, hydrolysis temperature, and water consumption on the yield and purity of MA were analyzed. Response surface methodology (RSM) was used to optimize conditions for the semi-batch synthesis process of MA. The best synthetic conditions for the formation of MA were reaction temperature 0.5 °C, hydrolysis temperature 70 °C and n (phthalimide)/ n (sodium hypochlorite)/ n (methanol) = 1:2.03:5.87, and water consumption m (H2 O)/ m (phthalimide) = 7.16:1. The yield of MA could reach 90% under the optimal conditions, which is more than 10% higher than that of the previous semi-batch process. Furthermore, the reaction mechanism was investigated by infrared spectroscopy analysis, and the mechanism of ester group formation and the structure of intermediate products are proposed. The byproduct of the reaction was studied by GC-MS analysis, a byproduct called 2-cyanobenzoic acid has been discovered. Therefore, an unprecedented reaction mechanism of the whole synthesis process is proposed. [ABSTRACT FROM AUTHOR]

Big data technology has greatly promoted the construction of intelligent administrative management and improved the decision-making ability continuously. Data mining also lays a solid foundation for the construction of administrative management platform and reflects the potential value of data. In this study, an intelligent management platform based on big data is designed and implemented. First, the problems of the intellectualization of administrative management are discussed, and the big data platform and functional framework of administrative management are introduced. Second, in order to apply data mining to administrative management, the object of data mining in administrative management is defined, and a data mining system is designed. Finally, the application of machine learning methods such as cluster analysis in administrative management is analyzed in detail. The research results show that the application of intelligent management platform based on big data can promote the construction of intelligent administration and lay a good foundation for the development of more perfect intelligent administrative management. [ABSTRACT FROM AUTHOR]

This paper interprets an image space accelerating branch and bound algorithm for globally solving a class of multiplicative programming problems (MP). In this algorithm, in order to obtain the global optimal solution, the problem (MP) is transformed into an equivalent problem (P2) by introducing new variables. By utilizing new linearizing relaxation technique, the problem (P2) can be converted into a series of linear relaxation programming problems, which provide the reliable lower bound in the branch and bound search. Meanwhile, an image space accelerating method is constructed to improve the computational performance of the algorithm by deleting the subintervals which have no global optimal solution. Furthermore, the global convergence of the algorithm is proved. The computational complexity of the algorithm is analyzed, and the maximum iterations of the algorithm are estimated. Finally, numerical experimental results show that the algorithm is robust and efficient. [ABSTRACT FROM AUTHOR]

In this paper, a full-order terminal sliding-mode control method is proposed for the rectifier side and the inverter side of the soft open point (SOP). The rectifier-side DC voltage control system consists of the voltage- and current-loops with controllers which are designed using full-order sliding-mode (FOSM) to enhance the dynamic performances and anti-disturbance. The integral type virtual control signal without chattering is designed to compensate for the unmatched uncertainties including external disturbances and some parameter perturbations. The full-order terminal sliding-mode (FOTSM) controller for the current-loop can force the current response to track its reference in finite time. The inverter side power control system is designed to regulate the power. The FOTSM controller for the power-loop ensures the power-tracking accuracy under a disturbed condition. Finally, the simulations demonstrate the effectiveness of the proposed controllers for the rectifier and inverter sides in the soft open point (SOP). [ABSTRACT FROM AUTHOR]

This paper presents a disturbance observer-based model predictive of super-twisting control for Soft Open Point (SOP). First, with the consideration of the disturbances caused by parameter mismatches and unmodelled dynamics, a super-twisting sliding-mode observer (STO) is proposed to observe the disturbances, and the observed disturbances are introduced into the inner-loop as the compensation to improve the anti-disturbance of SOP system. Second, the outer-loop controller is designed by applying the super-twisting sliding-mode control (STC) approach to improve the dynamic performance and robustness. Third, to deal with large current harmonics by traditional model predictive control (MPC), a Three-Vector-based MPC (TV-MPC) is proposed to increase the number of voltage vectors in a sampling time. Finally, it is verified by simulations that the proposed method can reduce current harmonics, DC-side voltage setting time and improve the dynamic performance of SOP system effectively. In case of parameter mismatches, the proposed observer can observe the disturbances correctly to enhance the robustness of the SOP system. [ABSTRACT FROM AUTHOR]

Cooperation of multiple robots in simultaneous localization and mapping (SLAM) systems has more advantages compared to single robot configurations such as a faster exploration speed of the environment and the ability to perform tasks with high complexity. In this paper, we present an online multi-robot SLAM system which merges range measurements provided by UWB sensors and Lidar data provided by different mobile robots to build a globally-consistent map that contains individual point cloud maps and the trajectory estimations of all the robots. The proposed system does not require overlaps between robot trajectories. However, when the maps of different robots overlap, the system can further refine the relative robot transformations. The performance of the proposed system is evaluated through two experiments. The results of the experiments show that the proposed system can achieve accurate environment mapping and self-positioning by the cooperation of multiple robots in real-time. [ABSTRACT FROM AUTHOR]

Soft open point (SOP) can improve the flexibility and reliability of power supplies; thus, they are widely used in distribution network systems. Traditional single-vector model predictive control (SV-MPC) can quickly and flexibly control the power and current at both ports of the SOP. However, SV-MPC can only select one voltage vector in a sampling time, producing large current ripples, and power fluctuations. In order to solve the above problems, this paper proposes a three-vector-based low complexity model predictive control (TV-MPC). In the proposed control method, two effective voltage vectors and one zero voltage vector are selected in a sampling time. For the two-port SOP, methods are given to judge the sectors on both sides and select the voltage vectors. Furthermore, the calculation method of the distribution time is proposed as well. Finally, the effectiveness of the proposed method is verified by steady-state and dynamic-state simulation results compared with the SV-MPC. [ABSTRACT FROM AUTHOR]

Favipiravir was chosen as a model for study on cocrystal screening of nucleoside analog. Seven coformer candidates were selected according to supramolecular synthon method and verified with molecular modeling and hot-stage. Only 4-amino benzoic acid was able to form cocrystal with the color transformation from white to yellow. Fluorescence study was investigated and compared during cocrystallization. Due to the fluorescent emission nature of nitrogen heterocyclic nucleoside analog, fluorescence could also be utilized as a promising tool in screening cocrystals. This study provides an efficient pathway toward nucleoside analog cocrystal and affords a fluorescent screening method for drug cocrystal research. [ABSTRACT FROM AUTHOR]

It has been proved that dual-armature permanent magnet (PM) machines have higher power density than conventional PM machines under the same copper loss. However, the thermal conditions of these machines are different. This paper makes a fair comparison between a dual-armature linear switched flux PM machine (DALSFPMM) and a linear surface-mounted PM machine (LSPMM) by considering both electromagnetic performances and thermal conditions. First, the topologies of two machines and platform are introduced. Then, the 2D and 3D finite element (FE) models are employed for the electromagnetic and thermal analyses, respectively. During the machine optimization, the thermal analysis is used to determine the copper loss under the fixed machine dimensions, while the electromagnetic analysis is used to optimize the machine dimensions under the fixed copper loss. After iterations, two machines are optimized and their performances are compared. Under the limitations of 80 °C maximum PM temperature and 120 °C maximum winding temperature, the DALSFPMM can exhibit 38% higher thrust force density for the continuous duty and up to 43% higher thrust force density for the short-time duty. Finally, a prototype machine of DALSFPMM is tested to validate the analyses. [ABSTRACT FROM AUTHOR]

A flexible hybrid integration strategy combing both advantages of the silicon chip and the printed polymer sensors is demonstrated for low cost smart packaging with internet-of-things connectivity. In the system, the silicon chip, as the general part, performs wireless energy harvesting, sensor signal acquisition, data processing and transmission through mature standard interfaces. The functions, form factor, and substrate of the printed polymer sensors can be customized according to the packaging requirements. To prove the feasibility, a 13.56 MHz radio frequency identification (RFID) chip with multi-sensor interface is designed and taped out. Ammonia and anti-open sensors are fabricated using the same conducting polymer (PEDOT:PSS) through solution printing processes. After characterization of their performance individually, a flexible smart packaging system is implemented with packed pork by integrating the RFID chip and the sensors onto a packaging film. Both the product quality and the integrity of the packaging are able to be conveniently inspected with a smartphone. [ABSTRACT FROM AUTHOR]

• Injection parameters of H 2 -rich gas over sintering process were optimized. • Experiment and numerical simulation were used to elucidate function mechanism. • A novel method on hydrogen-rich energy application in practical plants was developed. H 2 -rich gas has been widely regarded as a promising energy to substitute fossil energy in iron ore sintering process for CO 2 reduction. This investigation mainly focused on researching the influences of H 2 -rich gas injection parameters over sintering bed on sintering performance, and elucidated the potential function mechanism through both experiment and numerical simulation. Results indicated that increasing injection concentration and prolonging injection time within a proper range improved sinter quality, and the recommended value was 0.6∼0.8 % and 8 min, respectively. Injecting H 2 -rich gas at earlier sintering stages achieved greater improvement in sintering quality compared with the ones injecting at later sintering stages, and the recommended injection area was 5∼13min. Both experiment and numerical simulation results indicated that injecting H 2 -rich improved the thermal patterns of sintering bed, with extended high-temperature areas for increasing the generation of high-strength calcium ferrite. Especially when injecting H 2 -rich gas under the recommended parameters, the heat distribution in sintering bed was optimized and the sintering quality of upper sintering layer was obviously improved. Finally, an injection method for guiding the industrial application with its essence to inject H 2 -rich at earlier sintering stages was proposed. The research findings provide a promising way for the efficient utilization of clean energy in iron ore sintering plants. [ABSTRACT FROM AUTHOR]