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As the e-commerce landscape diversifies, suppliers are faced with the critical decision of how to effectively launch their products through e-commerce channels with varying business models. This study aims to explore the strategic considerations for a supplier launching products through two distinct e-commerce channels: one based on a direct sale model and the other on a reselling model. It builds a theoretical model to examine the supplier’s decision-making across three strategic options: a simultaneous launch through both channels, a sequential launch starting with the direct sale model followed by the reselling model, and vice versa. The equilibria of those options are derived through game analysis and further compared. The results reveal that for suppliers under a non-alliance pricing contract, a simultaneous product launch across both channels is the most advantageous approach. Conversely, in scenarios where an alliance pricing contract is in place, the optimal strategy shifts towards a sequential launch. The decision of which channel to ally with—whether the direct sale or the reselling model—hinges critically on the difference in service efficiency and the intensity of competition between the channels. This nuanced analysis highlights the importance of strategic flexibility and alignment with channel dynamics in maximizing product launch success in the evolving e-commerce environment.

The KLD segment of the Kenweiyuan section in Wenchang, Hainan, China is a set of aeolian sand deposits of the Last Deglaciation. The chemical element and heavy mineral analysis performed in this study reveals the chemical index of alteration (CIA) in the segment to be as high as 93–95, with all the heavy minerals identified as stable and extremely stable making up 38–45% of the total. Furthermore, the zircon, tourmaline, and rutile content (ZTR index) of the segment is determined to range between 48–71. The (Al2O3 + TOFE)/SiO2 ratios display obvious fluctuations from old to new strata in the segment, with the low values corresponding to Heinrich event (H1), Dansgaard-Oeschager (D-O), and Younger Dryas (YD) and the high values corresponding to Bølling and Allerød. Our study suggests that these fluctuations are attributed to the alternation of the East Asian winter and summer monsoons. Hainan Island is also impacted by the surface ocean climate of the South China Sea, and characteristics of the KLD segment may be connected to the climate changes in the North Atlantic related to the winter monsoon season or westerlies. Furthermore, the segment presents a clear response to millennium-scale climate changes during the Last Deglaciation on Hainan Island. Based on the high CIA values in the KLD segment, and particularly due to the observed stable detrital minerals, the ratios can be linked to the overall tropical climate, indicating a relatively warm tropical climate environment in the Last Deglaciation in Hainan. The high CIA values also reveal the cause of aeolian sand formation under the tropical environmental conditions in the low latitude region of China in the Late Quaternary.

Infant birth sizes are vital clinical parameters to predict poor growth and micronutrient deficiency in early life. However, their effects on childhood anemia remain unclear. We aimed to explore the associations between birth weight, crown–heel length, and head circumference with anemia in early childhood, as well as potential modification factors. This population-based prospective cohort study included 204,556 participants with singleton live births delivered at gestational ages of 28–42 weeks. A logistic regression model was used to estimate the associations of the measures of infant birth size and their Z-score with anemia under five years old. There were 26,802 (13.10%) children under five years old who were diagnosed has having anemia. Compared with children who did not have anemia, children who had anemia had a lower birth weight and smaller head circumference and a longer crown–heel length (all p-values < 0.05). After adjusting for confounders, not only birth weight (β coefficient, −0.008; 95% CI, −0.011–−0.004; p < 0.001) and head circumference (β coefficient, −0.004; 95% CI, −0.007–−0.001; p = 0.009), but also the related Z-scores were negatively associated with childhood anemia, while the trends for crown–heel length were the opposite. We further found significant interactions of folic acid use and maternal occupation with infant birth sizes. In conclusion, infants having abnormal sizes at birth are significantly associated with the risk for childhood anemia, which can be modified by folic acid use during pregnancy and maternal occupation.

Meloidogyne javanica is one of the most widespread and economically important sedentary endoparasites. In this study, a comparative transcriptome analysis of M. javanica between pre-parasitic second-stage juveniles (Pre-J2) and parasitic juveniles (Par-J3/J4) was conducted. A total of 48,698 unigenes were obtained, of which 18,826 genes showed significant differences in expression (p < 0.05). In the differentially expressed genes (DEGs) from transcriptome data at Par-J3/J4 and Pre-J2, a large number of unigenes were annotated to the C-type lectin (CTL, Mg01965), the cathepsin L-like protease (Mi-cpl-1), the venom allergen-like protein (Mi-mps-1), Map-1 and the cellulase (endo-β-1,4-glucanase). Among seven types of lectins found in the DEGs, there were 10 CTLs. The regulatory roles of Mj-CTL-1, Mj-CTL-2 and Mj-CTL-3 in plant immune responses involved in the parasitism of M. javanica were investigated. The results revealed that Mj-CTL-2 could suppress programmed cell death (PCD) triggered by Gpa2/RBP-1 and inhibit the flg22-stimulated ROS burst. In situ hybridization and developmental expression analyses showed that Mj-CTL-2 was specifically expressed in the subventral gland of M. javanica, and its expression was up-regulated at Pre-J2 of the nematode. In addition, in planta silencing of Mj-CTL-2 substantially increased the plant resistance to M. javanica. Moreover, yeast co-transformation and bimolecular fluorescence complementation assay showed that Mj-CTL-2 specifically interacted with the Solanum lycopersicum catalase, SlCAT2. It was demonstrated that M. javanica could suppress the innate immunity of plants through the peroxide system, thereby promoting parasitism.

There is an urgent need to design and synthesize non-noble metal electrocatalysts (NNMEs) for the replacement of platinum-based electrocatalysts to enhance the sluggish oxygen reduction reaction (ORR) for Zn–air batteries and fuel cells. Herein, Fe-N,S-C materials were fabricated through two steps: first, reprecipitating hemin by adjusting the pH and, then, decorating it with melamine and cysteine in the presence of Zn2+. The resulting Fe-N,S-C-950 (Zn) was prepared after pyrolysis at 950 °C. Using this method, abundant iron-based active species with good dispersion were obtained. The fabrication of more micropores in Fe-N,S-C-950 (Zn) plays a positive role in the improvement of ORR activity. On comparison, Fe-N,S-C-950 (Zn) outperforms Fe-N,S-C-950 and Fe-N-C-950 (Zn) with respect to the ORR due to its larger specific surface area, porous structure, multiple iron-based active sites and N- and S-doped C. Fe-N,S-C-950 (Zn) achieves outstanding ORR performances, including a half-wave potential (E1/2) of 0.844 V and 0.715 V versus a reversible hydrogen electrode (RHE) in 0.1 M KOH and 0.1 M HClO4 solution, respectively. In addition, Fe-N,S-C-950 (Zn) shows an outstanding Zn–air battery performance with an open-circuit voltage (OCV) of 1.450 V and a peak power density of 121.9 mW cm−2, which is higher than that of 20 wt% Pt/C. As a result, the as-prepared electrocatalyst in this work shows the development of the Zn-assisted strategy combined with the assembly of porphyrins as NNMEs for the enhancement of the ORR in both alkaline and acidic solutions.

This paper investigates the trajectory tracking control issue of four-wheel independently actuated electric vehicles (FWIA EVs) with steer-by-wire devices concerning parameter uncertainties, external disturbances, input saturation, and vehicle sideslip angle not easily obtained. A robust H∞ dynamic output feedback control strategy is proposed for the integrated control of the steering motor current and direct yaw moment without using sideslip angle information to ensure the reference trajectory tracking and the improvement of handling performance and yaw stability. In the proposed integration control framework, the steer-by-wire device dynamic is involved in the polyhedral linear parameter-varying (LPV) trajectory tracking error model considering the time-varying longitudinal velocity, and the norm-bounded parameter uncertainties such as road adhesion coefficient, tire cornering stiffness, vehicle mass, and vehicle moment of inertia. With the help of the LPV model of all the states of the steer-by-wire FWIA EV, a dynamic output feedback trajectory tracking controller is designed using the robust H∞ technique. The controller gain matrices are obtained by solving the linear matrix inequalities. Finally, the high-fidelity full-vehicle model based on the CarSim-MATLAB/Simulink joint simulation platform verifies the robustness and advantages of the designed control strategy in the accelerated lane-change scenario.

We performed this study to clarify the dynamic changes in maternal manganese (Mn) concentration during pregnancy and its association with spontaneous preterm birth (SPB). A nested case–control study was conducted based on the Beijing Birth Cohort Study (BBCS) from 2018 to 2020. Singleton pregnancy women aged 18–44 (n = 488) were involved in the study, including 244 cases of SPB and 244 controls. All of the participants provided blood samples twice (in their first and third trimesters). Inductively coupled plasma mass spectrometry (ICP-MS) was used for the laboratory analysis, and unconditional logistic regression was used for the statistical analysis. We found that the maternal Mn levels were significantly higher in the third trimester than those in the first trimester (median: 1.23 vs. 0.81 ng/mL). The SPB risk was increased to 1.65 (95% CI: 1.04–2.62, p = 0.035) in the highest Mn level (third tertile) in the third trimester, especially in normal-weight women (OR: 2.07, 95% CI: 1.18–3.61, p = 0.011) or non-premature rupture of membrane (PROM) women (OR: 3.93, 95% CI: 2.00–7.74, p < 0.001). Moreover, a dose-dependent relationship exists between the SPB risk and maternal Mn concentration in non-PROM women (P trend < 0.001). In conclusion, dynamic monitoring of maternal Mn level during pregnancy would be helpful for SPB prevention, especially in normal-weight and non-PROM women.

The pathological mechanisms of neural tube defects (NTDs) are not yet fully understood. Although the dysregulation of histone modification in NTDs is recognized, it remains to be fully elucidated on a genome-wide level. We profiled genome-wide H3K27me3 and H3K27ac occupancy by CUT&Tag in neural tissues from ICR mouse embryos with benzo[a]pyrene (BaP)-induced NTDs (250 mg kg−1) at E9.5. Furthermore, we performed RNA sequencing (RNA-seq) to investigate the regulation of histone modifications on gene expressions. Gene ontology and KEGG analysis were conducted to predict pathways involved in the development of NTDs. Our analysis of histone 3 lysine 27 modification in BaP-NTD neural tissues compared to BaP-nonNTD revealed 6045 differentially trimethylated regions and 3104 acetylated regions throughout the genome, respectively. The functional analysis identified a number of pathways uniquely enriched for BaP-NTD embryos, including known neurodevelopment related pathways such as anterior/posterior pattern specification, ephrin receptor signaling pathway, neuron migration and neuron differentiation. RNA-seq identified 423 differentially expressed genes (DEGs) between BaP-NTD and BaP-nonNTD group. The combination analysis of CUT&Tag and RNA-seq found that 55 DEGs were modified by H3K27me3 and 25 by H3K27ac in BaP-NTD, respectively. In the transcriptional regulatory network, transcriptional factors including Srsf1, Ume6, Zbtb7b, and Cad were predicated to be involved in gene expression regulation. In conclusion, our results provide an overview of histone modifications during neural tube closure and demonstrate a key role of genome-wide alterations in H3K27me3 and H3K27ac in NTDs corresponding with changes in transcription profiles.

Au particles are commonly used for deposition on the surface of a bipolar electrode (BPE) in order to amplify electrochemical and electrochemiluminescence (ECL) signal because of their excellent conductivity, biocompatibility, and large surface area. In this work, a closed BPE device was fabricated and Au particles were deposited on the two poles of a BPE via bipolar deposition. Results indicated that the electrochemical stability of Au film on the anode part of the BPE and the reduction of AuCl4– to Au on the cathode part of the BPE depended on the conductivity of the solution. The prepared Au–Au BPE exhibited a remarkable amplification effect on the ECL signal. Then, a specific sensing interface was constructed on one pole of the BPE for the visual detection of prostate-specific antigens (PSA) based on sandwich-type immunoreactions between primary PSA antibodies (Ab1) on the electrode surface, PSA, and SiO2 nanoparticles labeled secondary PSA antibodies (SiO2-Ab2). The designed biosensor exhibited a good linear relationship for the ECL detection of PSA in the range of 1 × 10−6 to 1 × 10−10 g/mL with a correlation coefficient of 0.9866; the limit of detection (LOD) was 1.5 × 10−11 g/mL. Additionally, the biosensor can realize the electrochemical imaging of PSA by regulating the electrochemical oxidation of the Au anode with the immunoreactions on the cathode part of BPE. Therefore, the small, portable and highly sensitive biosensors have great potential for on-site detection.

A novel Co-free non-equiatomic Ni2FeCr medium-entropy alloy (MEA) was designed, and the Hall–Petch strengthening by grain boundaries and annealing twin boundaries was investigated. For this purpose, the alloy was prepared by cold rolling and recrystallization at 873–1323 K for 40 min–6 h. Annealing at different temperatures revealed that Ni2CrFe alloy forms a stable face-centered cubic (FCC) solid solution. Mean grain sizes (excluding annealing twin boundaries) and mean crystallite sizes (including both grain and annealing twin boundaries) were determined using the linear intercept method and the equivalent circle diameter in electron back-scattered diffraction (EBSD) soft. Tensile tests at 293 K indicated that the Hall-Petch slopes of grain sizes and crystallite sizes are 673 and 544 MPa μm1/2, respectively, and this contribution was then subtracted from the overall strength to calculate the intrinsic uniaxial lattice strength (90 MPa). Additionally, tensile tests, performed between 293 K and 873 K, revealed that the Ni2CrFe MEA has a stronger resistance to softening at high temperatures. Transmission electron microscopy of deformed specimens revealed the formation of dislocation pile-ups at annealing twin boundaries, indicating that it is also an obstacle to dislocation slip. Furthermore, the thickening of the annealing twin boundary after deformation was observed and illustrated by the interaction between different dislocations and annealing twin boundaries.

The North Yellow Sea, located at the intersection of the Eurasian continent and North Pacific Ocean at mid-latitudes, is a sensitive area subjected to the joint actions of the ocean, land, and monsoons. On its southern shore, loess and paleosol sedimentary sequences were widely developed during the last interglacial period, which is of great significance for revealing patterns of climate change and dynamic conditions. In this paper, we focus on the Zhifu section (ZFS) on Zhifu Island within the Shandong Province of China. The optically stimulated luminescence (OSL) dating method was used to construct our chronological framework. Grain size and its endmember (EM) components were then analyzed; EM1 is a clay component EM, which represents a weak dynamic environment and strong weathering pedogenesis, while EM2 and EM3 are silt and very fine sand component EMs, respectively, representing a strong dynamic environment and weak weathering pedogenesis. Maximum EM1, mean grain size, clay content, and pH values occur in the paleosol layers (ZF4, ZF6, and ZF8), with minimum values in the loess layers (ZF5 and ZF7); EM3 values show the opposite pattern. This indicates that the ZF4, ZF6, and ZF8 layers represent warm and humid environments with abundant precipitation, where the East Asian summer monsoon (EASM) was enhanced, corresponding to Marine Isotope Stages (MIS) 5a, 5c, and 5e. In contrast, ZF5 and ZF7 represent sub-warm and humid environments with less precipitation, where the EASM was weakened, corresponding to MIS 5b and 5d. Among these stages, MIS5e is the warmest and wettest. These climatic events reveal the pattern of climate fluctuation over a ten-thousand-year timescale; they are synchronous with climate changes recorded in other geological repositories, such as cave stalagmites in southern China and sea-level fluctuations in the Yellow-Bohai Sea, which result from changes in global solar radiation.

The co-deposition between polyphenols and amines has been demonstrated in order to prepare positively charged nanofiltration (NF) membranes for multivalent cation rejection in recent years; however, the low reactivities of the involved polyphenols usually cause a long co-deposition time and unsatisfactory rejection. Herein, a novel plant polyphenol (PG) was co-deposited with tetraethylenepentamine (TEPA) in a much shorter time period to prepare positively charged NF with high multivalent cation rejection membranes. The performance of the co-deposition membranes can be easily controlled by adjusting the mass ratio of PG and TEPA, reaction time, and pH value of the buffer solution. The optimal membrane, prepared under a polyphenol and polyamine mass ratio of 1:1, coating time of 2 h, and pH value of 8.0, shows a decent pure water permeability of 8.43 L m−2 h−1 bar−1 while maintaining a superior 96.24% MgCl2 rejection. More importantly, the universality of this method was corroborated by employing other amines with different molecular weights in the co-deposition. This work provides new insights for the preparation of high-performance positively charged NF membranes.

In this work, we formulate the image in-painting as a matrix completion problem. Traditional matrix completion methods are generally based on linear models, assuming that the matrix is low rank. When the original matrix is large scale and the observed elements are few, they will easily lead to over-fitting and their performance will also decrease significantly. Recently, researchers have tried to apply deep learning and nonlinear techniques to solve matrix completion. However, most of the existing deep learning-based methods restore each column or row of the matrix independently, which loses the global structure information of the matrix and therefore does not achieve the expected results in the image in-painting. In this paper, we propose a deep matrix factorization completion network (DMFCNet) for image in-painting by combining deep learning and a traditional matrix completion model. The main idea of DMFCNet is to map iterative updates of variables from a traditional matrix completion model into a fixed depth neural network. The potential relationships between observed matrix data are learned in a trainable end-to-end manner, which leads to a high-performance and easy-to-deploy nonlinear solution. Experimental results show that DMFCNet can provide higher matrix completion accuracy than the state-of-the-art matrix completion methods in a shorter running time.

Objective: Comorbid congenital malformation of multiple organs may indicate a shared genetic/teratogenic causality. Folic acid supplementation reduces the population-level prevalence of isolated neural tube defects (NTDs), but whether complex cases involving independent malformations are also responsive is unknown. We aimed to describe the epidemiology of NTDs with comorbid malformations in a Chinese population and assess the impact of folic acid supplementation. Study Design: Data from five counties in Northern China were obtained between 2002 and 2021 through a population-based birth defects surveillance system. All live births, stillbirths, and terminations because of NTDs at any gestational age were recorded. NTDs were classified as spina bifida, anencephaly, or encephalocele. Isolated NTDs included spina bifida cases with presumed secondary malformations (hydrocephalus, hip dislocation, talipes). Non-isolated NTDs were those with independent concomitant malformations. Results: A total of 296,306 births and 2031 cases of NTDs were recorded from 2002–2021. A total of 4.8% of NTDs (97/2031) had comorbid defects, which primarily affected the abdominal wall (25/97), musculoskeletal system (24/97), central nervous system (22/97), and face (15/97). The relative risk of cleft lip and/or palate, limb reduction defects, hip dislocation, gastroschisis, omphalocele, hydrocephalus, and urogenital system defects was significantly greater in infants with NTDs than in the general population. Population-level folic acid supplementation significantly reduced the prevalence of both isolated and non-isolated NTDs. Conclusion: Epidemiologically, non-isolated NTDs follow similar trends as isolated cases and are responsive to primary prevention by folic acid supplementation. Various clinically-important congenital malformations are over-represented in individuals with NTDs, suggesting a common etiology.

Accurately predicting the critical differential pressure (CDP) of sand production contributes to improving the peak-shaving capacity and ensuring safe operation of underground gas storage (UGS). The CDP of sanding production in the target wells of the UGS was predicted coupling laboratory tests, inversed analysis with well logging data and numerical simulations. The in-situ mechanical properties of rock were estimated by coupling the laboratory test results and well-logging data. The in-situ stress field of the target formation was then deduced through inversed analysis coupled finite element method (FEM) and genetic algorithm (GA), based on the existing known stress data and the seismic data of the measured points. Using the critical strain limit (CSL) of 5‰ as the sanding criterion of the wellbore, the CDPs of the gas production in the UGS were predicted, which was 5.59 MPa, 3.98 MPa, and 4.01 MPa for well #1, well #2 and well #3, when the pressure of the gas storage was 30 MPa, respectively. The simulation results showed good agreements with the field-measured benchmark data of well #2 and well #3. The effects of moisture contents (ranging from 10 to ~40%), and cycling times of gas injection and withdrawal (ranging from 40 to ~200 cycling times) on the critical differential pressure were simulated and analyzed. The results indicated that the CDP decreased with an increase of the moisture content and the cycling times. This study provides a reliable tool for the sanding prediction of the wellbore in the UGS.

Hypertension during pregnancy may increase the risk of anemia in the offspring. However, few studies have investigated the effects of elevated blood pressure during the preconception period on childhood anemia. This large population-based birth cohort study was performed to determine whether abnormal preconception blood pressure has long-term consequences for childhood health. Data were obtained from the China–US Collaborative Project for Neural Tube Defect Prevention. The study consisted of 40,638 women with singleton live births who were registered in a monitoring system before pregnancy in southern China during the period 1993–1996. Children were assessed by hemoglobin measurement at approximately 53 months of age. The incidences of childhood anemia were 19.80% in the hypertension group and 16.07% in the non-hypertension group. Compared with the non-hypertension group, the hypertension group had an increased risk of childhood anemia (adjusted risk ratio (RR): 1.25; 95% confidence interval (CI): 1.11–1.41). After categorization according to blood pressure, combined systolic and diastolic hypertension was associated with a significantly increased risk of childhood anemia, compared with normotension (adjusted RR: 1.37; 95% CI: 1.16–1.63). Compared with women who had normal blood pressure, the adjusted RRs for childhood anemia were 1.20 (95% CI: 1.13–1.28), 1.26 (95% CI: 1.08–1.47), and 1.38 (95% CI: 1.14–1.67) among women with prehypertension, stage-1 hypertension, and stage-2 hypertension, respectively. Our results suggest a linear association between prepregnancy hypertension and the risk of childhood anemia in the Chinese population. Interventions targeting preconception blood pressure may have a positive effect on childhood health.

Gestational hypertension may interfere with the placental iron metabolism, thus probably increasing the risk of childhood anemia. We aim to examine the association between gestational hypertension and childhood anemia at different ages in two large Chinese birth cohorts. Cohort 1 was conducted in 5 counties in northern China and was comprised of 17,264 mother–children pairs (97.3%) during 2006–2009, whereas cohort 2 was conducted in 21 counties in southern China and was comprised of 185,093 mother–children pairs (93.8%) during 1993–1996. All pregnant women were registered in a monitoring system and followed up until the termination of pregnancies. The childhood anemia was diagnosed at 6 month and 12 month in cohort 1 and at 55 month in cohort 2. The overall incidence of childhood anemia was 6.78% and 5.28% at 6 month and 12 month, respectively, in cohort 1 and 13.18% at 55 month in cohort 2. Gestational hypertension was associated with increased risk of anemia at 6 month (adjusted Odds Ratio (OR): 1.31; 95% confidence interval (CI): 1.05, 1.63) and at 12 month (adjusted OR: 1.50; 95% CI: 1.18, 1.90) in cohort 1 and at 55 month (adjusted OR: 1.06; 95% CI: 1.01, 1.12) in cohort 2. The hemoglobin values of children at different ages were lower among gestational hypertension group in the linear models, which was consistent with the results of binary regression analysis. Our study found gestational hypertension may associate with an increased risk of childhood anemia. It suggests a possible need for exploring changes in prenatal care that might prevent childhood anemia.

Babies who are born small for their gestational age (SGA) have low iron reserves, thus probably increasing the risk of offspring anemia. We studied two longitudinal birth cohorts to evaluate the association of SGA with the risk of anemia during early childhood. Cohort 1 was recruited from five counties in northern China involving 17,180 singleton infants born during 2006–2009 and cohort 2 from 21 counties or cities in southern China involving 180,619 children born during 1993–1996. Anemia was diagnosed by hemoglobin at 6 and 12 months in cohort 1 and at 55 months in cohort 2. The overall incidences of SGA were 7.07% and 5.73% in cohort 1 and cohort 2, respectively. SGA was associated with increased anemia at 6 months (adjusted odds ratio (OR): 1.52; 95% confidence interval (CI): 1.24, 1.86) and 12 months (adjusted OR: 1.42; 95% CI: 1.13, 1.79) in cohort 1 and at 55 months (adjusted OR: 1.11; 95% CI: 1.05, 1.17) in cohort 2. The positive associations for anemia at 6, 12, and 55 months persisted in both logistics and multiple linear models. Our results support a gradually decreased association between SGA and the increased risk of childhood anemia with a longer follow-up time in infants and children.

The endoparasitoid body size hypothesis suggests that the size of larvae that develop in a single host should be subject to a trade-off: larger size could lead to increase overall fitness but could simultaneously increase the risk of resource depletion and starvation, resulting in a body size just below the host holding capacity. However, this hypothesis has not been rigorously tested using mathematical models thus far. The camellia weevil, C.styracis (Coleoptera: Curculionidae), is a notorious pest attacking fruits of Camellia oleifera Abel. and C. meiocarpa Hu., in which the larvae develop within a single fruit and larval development is limited by the available food resources. We developed a feasible method to test this hypothesis. First, five models were used to describe the relationship between larval mass and host size. Then, the minimum fruit threshold that had to be met for ad libitum larval development and the corresponding larval size (Wa) of this threshold were calculated based on the characteristics of the optimal model. Finally, the difference between the measured larval size and the predicted larval size (Wa) was determined. The results showed that (1) the data were better described by a logistic function than any other equation; (2) larval size in both host plants increased with increasing fruit size until leveling off when the fruits were large enough to allow unconstrained larval development; (3) larval size remained just below the host-fruit holding capacity, as there was no difference between the measured and predicted larval sizes (Wa); and (4) larvae developed in host plant with larger fruits had a larger size. These results confirmed the endoparasitoid body size hypothesis.

Less is known about the impact of maternal preconception anemia on birth outcomes. We aimed to examine associations between preconception hemoglobin (Hb) concentrations with risk of low birth weight (LBW) and small-for-gestational-age (SGA). This study was from a large population-based prospective cohort in China and included 124,725 women with singleton live births delivered at gestational ages of 28–45 weeks who were registered before pregnancy. Maternal Hb concentrations were measured during registration, and other health-related information was recorded prospectively. Logistic regression was used to evaluate the associations between preconception Hb concentrations with risk of LBW and SGA, adjusting for potential confounders. The results showed women with preconception anemia accounted for 22.28%. The incidences of LBW/SGA were 2.37%/6.30% among anemic women, and 2.01%/5.48% among non-anemic women, respectively. Preconception mild anemia increased by 17% (95% confidence interval (CI): 1.06, 1.28) and 14% (95% CI: 1.07, 1.21) the risk for LBW and SGA, while moderate-to-severe anemia had no significant association with LBW and SGA. Compared with the 120–129 g/L group, a U-shaped association was observed between preconception Hb concentrations with LBW and SGA. In conclusion, not only maternal anemia but also elevated Hb concentrations before pregnancy contribute to an increased risk of LBW and SGA.

The numerical accuracy of drop process simulation and collision response for drones is primarily determined by the finite element modeling method and simplified method of drone airframe structure. For light and small drones exhibiting diverse shapes and configurations, mixed materials and structures, deformation and complex destruction behaviors, the way of developing a reasonable and easily achieved high-precision simplified modeling method by ensuring the calculation accuracy and saving the calculation cost has aroused increasing concern in impact dynamics simulation. In the present study, the full-size modeling and simplified modeling methods that are specific to different components of a relatively popular light and small drone were analyzed in an LS-DYNA software environment. First, a full-size high-precision model of the drone was built, and the model accuracy was verified by performing the drop tests at the component level as well as the whole machine level. Subsequently, based on the full-size high-precision model, the property characteristics of the main components of the light and small drone and their common simplification methods were classified, a series of simplified modeling methods for different components were developed, several single simplified models and combined simplified models were built, and a method to assess the calculation error of the peak impact load in the simplified models was proposed. Lastly, by comparing and analyzing the calculation accuracy of various simplified models, the high-precision simplified modeling strategy was formulated, and the suggestions were proposed for the impact dynamics simulation of the light and small drone falling. Given the analysis of the calculation scale and solution time of the simplified model, the high-precision simplified modeling method developed here is capable of noticeably reducing the modeling difficulty, the solution scale and the calculation time while ensuring the calculation accuracy. Moreover, it shows promising applications in several fields (e.g., structure design, strength analysis and impact process simulation of drone).

To reduce the failure probability of rigid supporting structures caused by large deformation of deeply buried high-stress soft rock roadways, the mechanical properties and failure features of basalt fiber-rubber granular concrete (BFRGC) are investigated based on triaxial compression tests. The post-peak strain softening equations of BFRGC, based on the Mohr–Coulomb yield criterion, are deduced and then compiled in the finite-difference software (FLAC3D) to simulate the post-peak strain-softening process of BFRGC. Combined with practical engineering, the supporting effects of BFRGC with different proportions are evaluated by FLAC3D. The results of compression tests show that the yield strength of the BFRGC increases significantly when the mass percentage of basalt fiber is 0.4%. Moreover, mixing basalt fibers into both the plain concrete and rubber concrete can effectively restrain the development of the fractures under three-dimensional stress. The numerical results show that when the mass fractions of basalt fibers and rubber particles are 0.4% and 5–10%, respectively, both the plastic zone in the surrounding rocks and the deformation of the rigid supporting structures decrease obviously. It is indicated that the optimal ratio of BFRGC can effectively reduce the stress concentration around the roadway and improve the overall bearing capacity of the supporting structures.

During the process of automated crop picking, the two hand–eye coordination operation systems, namely “eye to hand” and “eye in hand” have their respective advantages and disadvantages. It is challenging to simultaneously consider both the operational accuracy and the speed of a manipulator. In response to this problem, this study constructs a “global–local” visual servo picking system based on a prototype of a picking robot to provide a global field of vision (through binocular vision) and carry out the picking operation using the monocular visual servo. Using tomato picking as an example, experiments were conducted to obtain the accuracies of judgment and range of fruit maturity, and the scenario of fruit-bearing was simulated over an area where the operation was ongoing to examine the rate of success of the system in terms of continuous fruit picking. The results show that the global–local visual servo picking system had an average accuracy of correctly judging fruit maturity of 92.8%, average error of fruit distance measurement in the range 0.485 cm, average time for continuous fruit picking of 20.06 s, and average success rate of picking of 92.45%.

In this work, LiFePO4/C composite were synthesized via a green route by using Iron (III) oxide (Fe2O3) nanoparticles, Lithium carbonate (Li2CO3), glucose powder and phosphoric acid (H3PO4) solution as raw materials. The reaction principles for the synthesis of LiFePO4/C composite were analyzed, suggesting that almost no wastewater and air polluted gases are discharged into the environment. The morphological, structural and compositional properties of the LiFePO4/C composite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman and X-ray photoelectron spectroscopy (XPS) spectra coupled with thermogravimetry/Differential scanning calorimetry (TG/DSC) thermal analysis in detail. Lithium-ion batteries using such LiFePO4/C composite as cathode materials, where the loading level is 2.2 mg/cm2, exhibited excellent electrochemical performances, with a discharge capability of 161 mA h/g at 0.1 C, 119 mA h/g at 10 C and 93 mA h/g at 20 C, and a cycling stability with 98.0% capacity retention at 1 C after 100 cycles and 95.1% at 5 C after 200 cycles. These results provide a valuable approach to reduce the manufacturing costs of LiFePO4/C cathode materials due to the reduced process for the polluted exhaust purification and wastewater treatment.

The effects of hydrothermal pretreatment (170–180 °C, 30–60 min) on the structural characteristics of enzymatic and extracted lignin from Triarrhena lutarioriparia (TL) during the integrated delignification process have been comprehensively investigated. Ion chromatography and NMR characterization showed that liquid products after mild hydrothermal process (170 °C, 30 min) were mainly composed of xylooligosaccharide (XOS) with different degrees of polymerization (DP ≥ 2). In addition, the structural changes of lignin during hydrothermal pretreatment and organic acid delignification process have been demonstrated by quantitative 2D heteronuclear single quantum coherence (2D-HSQC) and 31P-NMR techniques. Results showed that the structural changes of lignin (e.g., cleavage of β-O-4 linkages) induced by the hydrothermal pretreatment will facilitate the subsequent organic acid delignification process, and acetylated lignin could be obtained with a considerable yield, which can be used in lignin-based composite and candidate feedstock for catalytic upgrading of lignin. In short, the proposed process facilitates the producing of XOS and acetylated lignin for lignin valorization.

This is the second and final part of our Cesium Markup Language (CZML) study. Here, we describe the relevant applications, academic influence, and future developments of CZML. Since its emergence in 2011, CZML has become widely used in the geoscientific environment. It is also having a positive impact on geoscience. Numerous applications use CZML for generating time-dynamic geovisualization, facilitating data interoperability, and promoting spatial data infrastructures. In this paper, we give an overview of the available tools and services, representative applications, as well as the role that CZML plays for geoscientific research. Furthermore, we also discuss key similarities and differences between CZML and KML (Keyhole Markup Language), and outline some of the future improvements for CZML’s research and development.

Cesium Markup Language (CZML) is an emerging specification for the representation and exchange of time-dynamic geospatial objects on virtual globes. The principal focus of CZML is on the definition of time-varying characteristics that are important for applications of geospatial objects, such as changeable positions/extents, graphical appearances, and other geospatial properties. Due to its unique ability to stream massive geospatial datasets, CZML is ideally suited for efficient, incremental streaming to the client in the network environment. Our goal is to explore and outline the overall perspective of CZML as an efficient schema for representing time-dynamic geospatial objects on virtual globes. Such a perspective is the topic of the two present companion papers. Here, in the first part, we provide an overview of CZML and explore two key issues, and their associated solutions, for representing time-dynamic geospatial objects using CZML: one is how to use CZML properties to describe time-varying characteristics of geospatial objects, and the other is how to use CZML to support streaming data. These innovative improvements provide highly-efficient and more reliable supports for representing time-dynamic geospatial objects. The relevant applications, academic influence, and future developments of CZML are explored in a second paper.

Propofol is one of the main sedatives but its negative side effects limit its clinical application. Chitosan oligosaccharide (COS), a kind of natural product with anti-pain and anti-inflammatory activities, may be a potential adjuvant to propofol use. A total of 94 patients receiving surgeries were evenly and randomly assigned to two groups: 10 mg/kg COS oral administration and/or placebo oral administration before being injected with propofol. The target-controlled infusion of propofol was adjusted to maintain the values of the bispectral index at 50. All patients’ pain was evaluated on a four-point scale and side effects were investigated. To explore the molecular mechanism for the functions of COS in propofol use, a mouse pain model was established. The activities of Nav1.7 were analyzed in dorsal root ganglia (DRG) cells. The results showed that the patients receiving COS pretreatment were likely to require less propofol than the patients pretreated with placebo for maintaining an anesthetic situation (p < 0.05). The degrees of injection pain were lower in a COS-pretreated group than in a propofol-pretreated group. The side effects were also more reduced in a COS-treated group than in a placebo-pretreated group. COS reduced the activity of Nav1.7 and its inhibitory function was lost when Nav1.7 was silenced (p > 0.05). COS improved propofol performance by affecting Nav1.7 activity. Thus, COS is a potential adjuvant to propofol use in surgical anesthesia.

Three new 30-noroleanane triterpenoid saponins, akebonoic acid 28-O-β-d-glucopyranosyl-(1′′→6′)-β-d-glucopyranosyl ester (1), akebonoic acid 28-O-(6′′-O-caffeoyl)-β-d-glucopyranosyl-(1′′→6′)-β-d-glucopyranosyl ester (Holboelliside A, 2) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 3-O-(6′-O-caffeoyl)-β-d-glucopyranoside (Holboelliside B, 3) were isolated from the stems of Holboellia coriacea Diels, together with five known compounds, eupteleasaponin VIII (4), 3α-akebonoic acid (5), quinatic acid (6), 3β-hydroxy-30-norhederagenin (7) and quinatoside A (8). The structures of these compounds were determined on the basis of spectral and chemical evidence. Compounds 1–5 were evaluated for their inhibitory activity against three human tumors HepG2, HCT116 and SGC-7901 cell lines in vitro.

Demand response (DR) can ensure electricity supply security by shifting or shedding loads, which plays an important role in a power system with a high proportion of renewable energy sources. Industrial loads are vital participants in DR, but it is difficult to assess DR potential because of many complex factors. In this paper, a new method based on fuzzy control is given to assess the DR potential of industrial loads. A complete assessment framework including four steps is presented. Firstly, the industrial load data are preprocessed to mitigate the influence of noisy and transmission losses, and then the K-means algorithm considering the optimal cluster number is used to calculate baseline load of industrial load. Subsequently, an open-loop fuzzy controller is designed to predict the response factor of different industrial loads. Three strongly correlated indicators, namely peak load rate, electricity intensity, and load flexibility, are selected as the input of fuzzy control, which represents response willingness. Finally, the baseline load of diverse clustering scenarios and the response factor are used to calculate the DR potential of different industrial loads. The proposed method takes into account both economic and technical factors comprehensively, and thus, the results better represent the available DR potential in real-world situations. To demonstrate the effectiveness of the proposed method, the case of a medium-sized city in China is studied. The simulation focuses on the top eight industrial types, and the results show they can contribute about 189 MW available DR potential.

GaN Schottky diodes show great potential in high-power terahertz frequency multipliers. The thermal characteristics of GaN Schottky diodes with single and double-row anode arrangements are described in this paper. The temperature distribution inside the Schottky diode is discussed in detail under the coupling condition of Joule heat and solid heat transfer. The effects of different substrates and substrate geometric parameters on the thermal characteristics of the Schottky diode chips with single and double-row anode arrangements are systematically analyzed. Compared with that of the chip with single-row anode arrangement, the maximum temperature of the chip with double-row anode arrangement can be reduced by 40 K at the same conditions. For chips with different substrates, chips with diamond substrates can withstand greater power dissipation when reaching the same temperature. The simulation results are instructive for the design and optimization of Schottky diodes in the terahertz field.

The digital twin workshop contains a vast quantity of heterogeneous data from multiple sources, such as the historical state of workshop equipment, which is essential for analyzing implicit problems and bottlenecks in manufacturing tasks. Nevertheless, the current unidirectional and irreversible time flow of the digital twin workshop makes it difficult to optimize workshop productivity using historical data. This paper proposes a scene equipment saving and loading method for the digital twin workshop to address this issue. The initial steps involve defining a workshop information model which represents multiple pieces of workshop equipment in the virtual space and the content of the data it covers. This model stores data for each object type on the workshop using distinct data structures; a workshop element data saving and loading method is proposed, which can save the historical scene equipment data of the digital twin workshop and load the saved data into the digital twin software; finally, a case study is conducted to determine the data compatibility, the saving and loading efficiency, and the system’s ability to save and load actual workshop scenes. The results demonstrate that this method can efficiently save and load scene equipment data on the workshop, enabling workshop administrators to identify problems and bottlenecks in historical manufacturing tasks and then take steps to increase workshop productivity.

Human epidermal growth factor receptor-3 (HER-3) plays a key role in the growth and metastasis of cancer cells. The detection of HER-3 is very important for early screening and treatment of cancer. The AlGaN/GaN-based ion-sensitive heterostructure field effect transistor (ISHFET) is sensitive to surface charges. This makes it a promising candidate for the detection of HER-3. In this paper, we developed a biosensor for the detection of HER-3 with AlGaN/GaN-based ISHFET. The AlGaN/GaN-based ISHFET biosensor exhibits a sensitivity of 0.53 ± 0.04 mA/dec in 0.01 M phosphate buffer saline (1× PBS) (pH = 7.4) solution with 4% bovine serum albumin (BSA) at a source and drain voltage of 2 V. The detection limit is 2 ng/mL. A higher sensitivity (2.20 ± 0.15 mA/dec) can be achieved in 1× PBS buffer solution at a source and drain voltage of 2 V. The AlGaN/GaN-based ISHFET biosensor can be used for micro-liter (5 μL) solution measurements and the measurement can be performed after incubation of 5 min.

Sixty percent of the failures of launch vehicles in the ascending phase occur in the propulsion system. Among them, the vibration generated by the engine is an important factor in the occurrence of failure. At present, health assessment methods in the aerospace field are mostly for specific equipment, and scholars mostly assess the real-time health status of launch vehicle engines which can only reflect the current health status of the launch vehicle. Existing methods cannot be applied to different equipment, and there is a lack of research on health assessments of fuzzy and complex mechanical systems. In this article, we propose a multi-layer and multi-factor predictive evaluation method for a fuzzy and complex system and conduct experiments on real vibration data of rockets. First, we divide the health assessment level according to the vibration data that affect the normal operation of the rocket. Secondly, we obtain the future trend of vibration signals based on five data prediction methods and calculate the health status interval of the rocket engine’s working conditions based on the boxplot method. At the same time, we calculate the single health evaluation set of every vibration signal. We obtain the weights of each level and factor for the health value based on an analytic hierarchy process (AHP). The optimization of this step avoids an over-reliance on expert experience. Finally, we complete a fuzzy comprehensive evaluation of the engine system from the bottom up to obtain the final health value. The minimum evaluation error is 0.0193% on the test data of the Long March series launch vehicle engine, which shows that the proposed method can successfully predict and evaluate the launch vehicle engine.

The reliability and safety of launch vehicle launch missions might be effectively increased thanks to the fault prediction and health management (PHM) technology of engines, which could also improve with problem diagnostics and decrease the cost of operation and maintenance overhaul. This paper combines the equipment characteristics and the current state of safeguarding for large, complex space systems, introduces the intelligent launch vehicle engine PHM technology methods that are being gradually implemented in space systems, and discusses and compares fault detection and health assessment techniques. Subsequently, analysis of the measurement signals from a rocket engine was performed using an example, and it was shown that the established comprehensive health assessment structure, which is based on the fault prediction algorithm method and the fuzzy comprehensive assessment method, could successfully realize the effectiveness of the rocket engine system health assessment, which had an outstanding application value.

The present paper is concerned with the uniform boundedness of the normalized eigenfunctions of Sturm–Liouville problems and shows that the sequence of eigenvalues is uniformly local Lipschitz continuous with respect to the weighted functions.

This study aimed to achieve the accurate and real-time geographic positioning of UAV aerial image targets. We verified a method of registering UAV camera images on a map (with the geographic location) through feature matching. The UAV is usually in rapid motion and involves changes in the camera head, and the map is high-resolution and has sparse features. These reasons make it difficult for the current feature-matching algorithm to accurately register the two (camera image and map) in real time, meaning that there will be a large number of mismatches. To solve this problem, we used the SuperGlue algorithm, which has a better performance, to match the features. The layer and block strategy, combined with the prior data of the UAV, was introduced to improve the accuracy and speed of feature matching, and the matching information obtained between frames was introduced to solve the problem of uneven registration. Here, we propose the concept of updating map features with UAV image features to enhance the robustness and applicability of UAV aerial image and map registration. After numerous experiments, it was proved that the proposed method is feasible and can adapt to the changes in the camera head, environment, etc. The UAV aerial image is stably and accurately registered on the map, and the frame rate reaches 12 frames per second, which provides a basis for the geo-positioning of UAV aerial image targets.

This study proposes a novel reduced-order model (ROM), based on the Volterra series, for the aerodynamic force of the bridge deck section. Moreover, the ROM of the aerodynamic force of the streamlined box girder section of the Great Belt East Bridge (GBEB) is identified with computational fluid dynamic (CFD) simulations. Furthermore, an analysis method combining ROM aerodynamic force and Newmark-β integration is established to simulate the aeroelastic responses of the bridge deck section. Finally, the wind-induced vibration responses of the GBEB section are calculated near the flutter critical wind speed based on the Volterra series-based aeroelastic analysis and the fluid–structure interaction (FSI) numerical simulations in ANSYS Fluent, respectively. Moreover, to verify the applicability of the proposed method, the aeroelastic responses of the main deck section with the crash barriers of Lingdingyang Bridge (LDYB) are also simulated via the Volterra model and Newmark-β integration near the flutter critical wind speed. The results show that the first-order truncated Volterra model established in this study can accurately capture the aerodynamic response of the main girder, and the results are in good agreement with those of the CFD numerical simulation under forced vibration. Furthermore, the proposed method combined with ROM aerodynamic force and Newmark-β integration can effectively calculate the FSI of the bridge girder. The numerical results of the flutter critical wind speed and flutter frequency of GBEB and LDYB are consistent with the numerical results by the FSI method based on ANSYS Fluent and the existing numerical and experimental results, respectively.

Calculations of first principles were employed to explore the elastic constants of the β-Mg17Al12 intermetallic complex under pressure, along with several related physical parameters, including the bulk modulus, the shear modulus, Young’s modulus, Poisson’s ratio, and the anisotropy index. The volume of the β-Mg17Al12 crystal in the ground state was V0 = 1180.353 Å3, and the lattice parameter was 10.57 Å. This is in agreement with the available results in the literature, which indicate that the calculations were correct. The three independent elastic constants, C11, C12, and C44, increased with increasing pressure. The bulk modulus B, shear modulus G, and Young’s modulus E increased with increasing pressure, indicating that the bulk deformation resistance, shear deformation resistance, and stiffness of the β-Mg17Al12 phase increased with increasing pressure. The phase had a B/G > 1.75 and a Poisson’s ratio of ν > 0.26 and increased with pressure, indicating that the β-Mg17Al12 crystals were ductile and that the ductility increased with pressure. The Cauchy pressure C12–C44 increased with increasing pressure. The anisotropy coefficients A(100) and A(110) deviated further from 1, and the anisotropy increased. The electronic structure calculations showed that the total density of the states (TDOS) was achieved mainly by the Mg-3p and Al-3p states, and the total density of states moved toward the higher energy regions under pressure, with enhanced interatomic bonding, leading to an increase in the elastic constants and ultimately to an increase in each physical property with increasing pressure.

Diabetic kidney disease (DKD) is a major complication of diabetes mellitus (DM) and the leading cause of end-stage kidney disease (ESKD) worldwide. A significant number of drugs have been clinically investigated for the treatment of DKD. However, a large proportion of patients still develop end-stage kidney disease unstoppably. As a result, new effective therapies are urgently needed to slow down the progression of DKD. Recently, there is increasing evidence that targeted drug delivery strategies such as large molecule carriers, small molecule prodrugs, and nanoparticles can improve drug efficacy and reduce adverse side effects. There is no doubt that targeted drug delivery strategies have epoch-making significance and great application prospects for the treatment of DKD. In addition, the proximal tubule plays a very critical role in the progression of DKD. Consequently, the purpose of this paper is to summarize the current understanding of proximal tubule cell-targeted therapy, screen for optimal targeting strategies, and find new therapeutic approaches for the treatment of DKD.

Traditional GaAs-based frequency multipliers still exhibit great challenges to meet the demand for solid-state high-power THz sources due to low breakdown voltage and heat dissipation of the Schottky barrier diode (SBD). In this study, a GaN SBD chain was fabricated with n−/n+-GaN structure. As a consequence, the breakdown voltage of 54.9 V at 1 μA and cut-off frequency of 587.5 GHz at zero bias were obtained. A 120 GHz frequency-doubler module based on the GaN SBD chain was designed and fabricated. When driven with 500 mW input power in a continuous wave, the output power of the frequency-doubler module was 15.1 mW at 120 GHz. Moreover, the experiments show that the frequency-doubler module can endure an input power of 2 W. In addition, it is worth noting that the SBD chain works well at an anode temperature of 337.2 °C.

In this work, the epitaxial semipolar (11–22) AlN was prepared on nonpolar m-sapphire substrate by combining sputtering and high-temperature annealing. According to our systematic measurements and analysis from XRD, Raman spectra, and AFM, the evolution of crystalline structure and morphology was investigated upon increasing AlN thickness and annealing duration. The annealing operation intensively resets the lattice and improves the crystalline quality. By varying the film thickness, the contribution from the AlN-sapphire interface on crystalline quality and lattice parameters during the annealing process was investigated, and its contribution was found to be not so obvious when the thickness increased from 300 nm to 1000 nm. When the annealing was performed under durations from 1 to 5 h, the crystalline quality was found unchanged; meanwhile, the evolution of morphology was pronounced, and it means the crystalline reorganization happens prior to morphology reset. Finally, the annealing treatment enabled a zig-zag morphology on the AlN template along the sapphire [0001] direction in the plane, which potentially affects the subsequent device epitaxy process. Therefore, our results act as important experience for the semipolar nitride semiconductor laser device preparation, particularly for the epitaxy of microcavity structure through providing the crystalline evolution.

In the present work, a single-crystalline epitaxial nonpolar a-plane AlN film with in-plane two-folder symmetries was successfully achieved on an r-plane sapphire substrate, by combining physical vapor deposition and a high-temperature annealing technique. Moreover, by varying the AlN thickness, the evolution of crystalline quality and structure were systematically investigated using X-ray diffraction, Raman spectroscopy, and atomic force microscopy. The crystalline quality was much improved by the annealing treatment. Most importantly, when the thickness of AlN was increased up to 1000 nm, the AlN lattice was found to endure strong distortion along the out-of-plane direction, and the lattice showed an obvious expansion. The change of the surface morphology induced by high-temperature annealing was also tracked, and the morphology displayed structural anisotropy along the [11¯00] direction. Our results act as a crucial platform to better understand and employ the nonpolar AlN template; in particular, it is of importance for subsequent device fabrication.

Extrusion experiments and 3D numerical modeling were conducted to investigate the dynamic recrystallization and welding quality of a 6063 aluminum alloy hollow square tube extruded by a porthole die at the ram speeds of 3 mm/s, 7 mm/s, 9 mm/s and 11 mm/s. The results showed that average grain size of hollow square tube extruded at the ram speed of 7 mm/s was the smallest. The profile extruded at the ram speed of 3 mm/s exhibited the highest expansion ratio. Dynamic recrystallization (DRX) fractions were highly variable at different ram speeds. DRX fractions in the matrix zones were higher than those in the welding zones, resulting in smaller grain sizes in the matrix zones. Mechanical properties in the welding zones and matrix zones was different. A local strain concentration would occurred during expansion, which would affect the welding quality. Finally, it was found that the uniform microstructure near the welding line would also affect the welding quality.

Carbon fiber reinforced plastics (CFRP) are widely used in aerospace and new energy vehicles due to their high specific strength and flexible design ability. At present, the traditional forming process of CFRP curved surface components has problems of low mechanical properties and long processing time. In this paper, a new method of hot gas forming was proposed to obtain CFRP components. By applying high temperature and high-pressure gas on one side of CFRP, the material was forced to deform and solidify at the same time. A special device for hot gas forming was designed and developed. The curing behavior and mechanical properties of original CFRP plates were studied. The main defects and the corresponding control methods of hot gas forming parts were analyzed by forming spherical parts, and the feasibility of the hot gas forming process was verified. Taking the battery cover plate of a new energy vehicle as the research object, the influence of forming temperature, gas pressure, pressurization rate and other process parameters on the mechanical properties of complex CFRP components were analyzed. The mechanism of both strength and efficiency improvement was analyzed. The results showed that with the increasing of gas pressure, the tensile strength and forming efficiency of the CFRP curved components were improved obviously. Under reasonable forming parameters, the tensile strength of the obtained parts was increased by 37%, and the forming efficiency was increased by 58%. The fiber bundles were distributed more evenly and compactly under the hot gas forming. This showed that the use of hot gas forming had good potential in the preparation of high-performance CFRP parts, which was helpful to improve the processing efficiency and forming quality of CFRP curved parts in the aerospace and new energy automotive fields.