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The effects of projectile/target impedance matching and projectile shape on energy, momentum transfer and projectile melting during collisions are investigated by numerical simulation. By comparing the computation results with the experimental results, the correctness of the calculation and the statistical method of momentum transfer coefficient is verified. Different shapes of aluminum, copper and heavy tungsten alloy projectiles striking aluminum, basalt, and pumice target for impacts up to 10 km/s are simulated. The influence mechanism of the shape of the projectile and projectile/target density on the momentum transfer was obtained. With an increase in projectile density and length-diameter ratio, the energy transfer time between the projectile and targets is prolonged. The projectile decelerates slowly, resulting in a larger cratering depth. The energy consumed by the projectile in the excavation stage increased, resulting in lower mass-velocity of ejecta and momentum transfer coefficient. The numerical simulation results demonstrated that for different projectile/target combinations, the higher the wave impedance of the projectile, the higher the initial phase transition velocity and the smaller the mass of phase transition. The results can provide theoretical guidance for kinetic impactor design and material selection.

Abstract Background Microsatellite instability-high (MSI-H) is a unique genomic status in many cancers. However, its role in the genomic features and immunotherapy in cholangiocarcinoma (CCA) is unclear. This study aimed to systematically investigate the genomic characterization and immunotherapy efficacy of MSI-H patients with CCA. Methods We enrolled 887 patients with CCA in this study. Tumor samples were collected for next-generation sequencing. Differences in genomic alterations between the MSI-H and microsatellite stability (MSS) groups were analyzed. We also investigated the survival of PD-1 inhibitor-based immunotherapy between two groups of 139 patients with advanced CCA. Results Differential genetic alterations between the MSI-H and MSS groups included mutations in ARID1A, ACVR2A, TGFBR2, KMT2D, RNF43, and PBRM1 which were enriched in MSI-H groups. Patients with an MSI-H status have a significantly higher tumor mutation burden (TMB) (median 41.7 vs. 3.1 muts/Mb, P

ABSTRACT: Dietary absorption and digestion are influenced by the microbiota, morphology, and digestive enzymes of intestines, and fermentation is a popular and effective technique to enhance animal rearing growth performance. This study aims to explore the pivotal role of Muscovy duck probiotics fermented feedstuff (FF) in altering the growth performance by reshaping gut morphology, microorganisms and metabolism. The findings showed that FF considerably raised the levels of fatty acids (FA) and small peptides (7-19AA) in the diet. Further feeding trial data reveals that FF greatly increased the Muscovy duck average daily gain (ADG) but had no effect on their daily feed intake (DFI), and the FCR significantly dropped (P < 0.05). Additionally, it was evident that FF improved the integrity of the intestinal mucosa in Muscovy duck by increasing villus height, villus height-to-crypt depth ratio, and lowering crypt depth. Then, in comparison to the control group (NC), there was a significant increase in the gene expression of the mucosal tight junction proteins Occludin, Claudin-1, and Zo-1 in the intestine of Muscovy duck. Additionally, there was higher expression of the mucosal transport channels SGLT-1, PepT1, AQP2, AQP3, and AQP10 in the similarly colon site, jejunum, and duodenum. Furthermore, in AB-PAS/PAS-stained duodenum, jejunum, ileum, and similarly colon site, FF markedly increased relative mucus output and goblet cells while decreasing epithelial cell apoptosis. Following 16S sequencing data indicated that the intestinal microbiota was altered and the diversity and richness of gut microbes was greatly enhanced by FF. Particularly, the boost of core probiotics, such as Rothia of duodenum, Limosilactobacillus and Lentilactobacillus of jejunum, Lactococcus and Rothia of ileum, Ligilactobacillus and Entocuccus of similarly colon site, Gallibacterium of caecum. And reduced potentially pathogenic bacteria (Campylobacter, Prevotellaceae, Clostridia-vadinBB60, and Oscillospira). Nontargeted metabolomics assay for intestinal content confirmed an increased organic acids (oxidanesulfonic acid, cholic acid, gallic acid, coumaric acid, pipecollc acid, 13s-hydroxyoctadecadienoic acid) and glycosides metabolites (5-hydroxydantrolene, 3-hydroxyguanfacine glucuronide, acetylleucine, astragalin, xanthosine, taxiphylin, sinapine, denudatine, penylalanyl-tyrosine and phenylalanyl-valine). These findings demonstrated that FF, a viable option to improve Muscovy duck growth performance through reconstructed intestinal morphology, microorganisms, and metabolism, subsequently promoted the gut health and increased diet digestion and absorption. The study that is being presented offers scientific proof that FF might be a useful strategy for improving Muscovy duck growth performance.

Rubble-pile asteroids may be the type of near-Earth object most likely to threaten Earth in a future collision event. Small-scale impact experiments and numerical simulations for large-scale impacts were conducted to clarify the size ratio of the boulder/projectile diameter effects on ejecta size–velocity distribution. A series of small-scale impact cratering experiments were performed on porous gypsum–basalt targets at velocities of 2.3 to 5.5 km·s−1. Three successive ejection processes were observed by high-speed and ultra-high-speed cameras. The momentum transfer coefficient and cratering size were measured. A three-dimensional numerical model reflecting the random distribution of the interior boulders of the rubble-pile structure asteroid is established. The size ratio (length to diameter) of the boulder size inside the asteroid to the projectile diameter changed from 0.25 to 1.7. We conducted a smoothed particle hydrodynamics numerical simulation in the AUTODYN software to study the boulder size effect on the ejecta size–velocity distribution. Simulation results suggest that the microscopic porosity on regolith affects the propagation of shock waves and reduces the velocity of ejecta. Experiments and numerical simulation results suggest that both excavation flow and spalling ejection mechanism can eject boulders (0.12–0.72 m) out of the rubble-pile asteroid. These experiments and simulation results help us select the potential impact site in a planetary defense scenario and reduce deflection risk. are comprised primarily of boulders of a range of sizes.

Recently, image generation technology has demonstrated surprising effects. However, precisely recognizing the emotion in sound to accurately express it on the face of a designated person is a huge challenge. To address this challenge, a new framework, Sound to Expression (S2E), which can use the emotion in sound to guide facial expression image generation, is proposed. A speech dataset for emotion recognition is constructed. S2E can edit facial expressions with different emotions in sounds for different people. S2E consists of Continuous Wavelet Transform (CWT), YOLOv3, ChatGPT-3, and facial expression diffusion editing model (FEDEM). CWT is utilized to extract emotional features from different sounds. YOLOv3 is employed to identify the emotion categories. The emotion category and a specific person's name are input into ChatGPT-3 to randomly generate a description of the person and emotion. The description is input into FEDEM to generate a facial expression image. To generate more accurate images and address emotional semantic deviation, a new facial detail emotional preservation loss is proposed. The experimental results show that S2E can accurately recognize the emotion in the voice and use this emotion to guide the editing of the facial expression for the specified person to generate more accurate images.

Understanding the mutation landscape of cancer may enable the development of more targeted therapies. Here, the authors sequence a panel of genes in a large Asian cohort and compare to American cohorts and find 64% of the Asian patients have actionable mutations.

This paper proposes a reconfigurable dual-band bandpass filter with independently tunable center frequencies that is intended to be integrated into reconfigurable multiband global navigation satellite system receivers. The center frequencies can be adjusted within the range of 1160-1280 MHz and 1530-1630 MHz for the two passbands, respectively. To achieve the design goal, the input and output feed lines are shared by a pair of quarter-wave uniform impedance resonators and a stub-loaded stepped impedance resonator with terminal-loaded varactor bias circuits. The electric length of the transmission lines is changed by using bias voltage to control the varactor diodes, thereby changing the operating frequencies of the dual-band filter’s two passbands, and the independent reconfigurability of the two passbands is realized. The insertion loss is less than 1.5 dB and the return loss is better than 26 dB in all tuning ranges. The proposed dual-band reconfigurable filter demonstrates the flexibility of controlling the passband independently to be compatible with multistandard signals, which can accommodate the deployment of new GNSS standard specifications.

Background Growth differentiation factor 15(GDF15) is a distant member of the superfamily of the transforming growth factor beta (TGF-β). It has been established that increased GDF15 levels are associated with an increased risk of cardiovascular disease. However, the detail effect of GDF15 on cardiovascular system in patients with chronic kidney disease (CKD) needs detail analysis. Methods Patients with CKD who did not need dialysis were enrolled in the study. Blood pressure (BP), endothelial function, pulse wave velocity (PWV) and heart rate variability (HRV) were taken in all subjects. Plasma GDF15 concentration was measured by an enzyme-linked immunosorbent assay. Results Among the 355 participants, the mean age was 57.4 (±14.2) years old and the mean estimated glomerular filtration rate (eGFR) was 50.1 (±33.2) mL/min/1.73m2. The average plasma GDF15 level was 1394.7 (±610.1) pg/mL. Higher GDF15 concentrations were significantly associated with decreased eGFR and increased urine protein-to-creatinine ratio (uPCR). In multivariable models, after adjusting for potential confounders, plasma GDF15 has negative concerning with HRV parameters including the standard deviation of the normal-to-normal (NN) interval (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD) and Triangular Index. Conclusion We observed there was a link between increased plasma of GDF15 and decreased HRV. The mechanisms and prediction of GDF15 in the cardiovascular disease with CKD needs further discussion and study.

Based on the study of the geological background, it is considered that the main factors affecting helium enrichment in the northern margin of the Qaidam Basin (NMQB) are widely distributed rock masses, developed fractures, groundwater system, and more. Among these factors, the rock masses provide sufficient helium gas source, while the fractures and the groundwater system provide good natural gas migration channels and carriers. 4He, 20Ne, and other rare gas isotopes have a good linear relationship, which proves that the groundwater system plays a vital role in the helium enrichment process, and helium flux is high. Based on the theoretical understanding of helium reservoir formation formed by helium investigation in the Weihe Basin and its adjacent areas, it is predicted that the NMQB has the prospect of crustal helium resources. Through the analysis of natural gas wellhead samples in the helium prospective areas of the Mabei and Dongping gas fields in this area, it is found that the helium content is generally high. Isotope analysis shows that helium in this area is typically crust sourced. Furthermore, 21 out of the 22 source helium samples analyzed in this paper meet or exceed the industrial standard. According to the average helium gas volume fraction of sixteen samples in the Mabei area of 0.28%, Mabei area alone can become an extensive helium resource prospective area. Through further investigation and evaluation, it is expected to obtain super large helium reserves in the study area.

Abstract In this study, daidzein long-circulating liposomes (DLCL) were prepared using the ultrasonication and lipid film-hydration method. The optimized preparation conditions by the orthogonal design was as follows: 55 to 40 for the molar ratio of soybean phosphatidylcholine (SPC) to cholesterol, 1 to 10 for the mass ratio of daidzein to total lipid (SPC and cholesterol) (w:w), the indicated concentration of 5% DSPE-mPEG2000 (w:w), 50 °C for the hydration temperature, and 24 min for the ultrasonic time. Under these conditions, the encapsulation efficiency and drug loading of DLCL were 85.3 ± 3.6% and 8.2 ± 1.4%, respectively. The complete release times of DLCL in the medium of pH 1.2 and pH 6.9 increased by four- and twofold of that of free drugs, respectively. After rats were orally administered, a single dose of daidzein (30 mg/kg) and DLCL (containing equal dose of daidzein), respectively, and the MRT0−t (mean residence time, which is the time required for the elimination of 63.2% of drug in the body), t 1/2 (the elimination half-life, which is the time required to halve the plasma drug concentration of the terminal phase), and AUC0−t (the area under the plasma drug concentration-time curve, which represents the total absorption after a single dose and reflects the drug absorption degree) of daidzein in DLCL group, increased by 1.6-, 1.8- and 2.5-fold as compared with those in the free group daidzein. Our results indicated that DLCL could not only reduce the first-pass effect of daidzein to promote its oral absorption, but also prolong its mean resident time to achieve the slow-release effect.

Sulfometuron methyl (SM) is a widely used herbicide and thus leading to accumulation in the environment. The toxicity assessments of SM in model organisms are currently rare. In the present study, zebrafish were utilized for evaluating the detrimental effects of SM in aquatic vertebrates. Zebrafish embryos were exposed to 0, 10, 20, and 40 mg/L SM from 5.5 to 72 h post-fertilization (hpf), respectively. Consequently, SM exposure resulted in increasing the mortality rate and reducing hatching rate in larval zebrafish at 10, 20, and 40 mg/L SM-treated groups. The reduced numbers of immune cells (neutrophils and macrophages) were observed after SM exposure by a dose-dependent manner. The inflammatory responses (TLR4, MYD88, IL-1β, IL-6, IL-8, IFN-γ, IL-10, and TGF-β) were measured to estimate immune responses. Anti-inflammatory factors (IL-10 and TGF-β) were down-regulated in all the treated groups and significantly altered at 40 mg/L exposure group. Additionally, behavioral tests suggested that SM treatment significantly increased the total distance, average speed, and maximum acceleration of larval zebrafish during light-dark transition and subsequently enzymology test displayed the same trend to locomotor behaviors. The content significantly increased in oxidative stress, as reflected in ROS level in all the treated groups. The numbers of cell apoptosis were significantly increased at 20, and 40 mg/L and the highest concentration group induced the substantial increment (P

Background An artificial intelligence vessel segmentation tool, Fully Automated and Robust Analysis Technique for Popliteal Artery Evaluation (FRAPPE), was used to analyze a large databank of popliteal arteries imaged through the OAI (Osteoarthritis Initiative) to study the impact of atherosclerosis risk factors on vessel dimensions and characterize remodeling patterns. Methods and Results Magnetic resonance images from 4668 subjects contributing 9189 popliteal arteries were analyzed using FRAPPE. Age ranged from 45 to 79 years (median, 61), and 58% were women. Mean lumen diameter, mean outer wall diameter, and mean wall thickness (MWT) were measured per artery. Their median values were 5.8 mm (interquartile range, 5.2–6.5 mm), 7.3 mm (interquartile range, 6.7–8.1 mm), and 0.78 mm (interquartile range, 0.73–0.84 mm) respectively. MWT was associated with multiple cardiovascular risk factors, with age (4.2% increase in MWT per 10‐year increase in age; 95% CI, 3.9%–4.5%) and sex (8.6% higher MWT in men than women; 95% CI, 7.7%–9.3%) being predominant. On average, lumen and outer wall diameters increased with increasing MWT until the thickness was 0.92 mm for men and 0.84 mm for women. After this point, lumen diameter decreased steadily, more rapidly in men than women (−7.9% versus −6.1% per 25% increase in MWT; P

Abstract Background The reactive hyperemia index (RHI), measured by peripheral arterial tonometry (PAT), is a novel measurement of endothelial function and has been proven to be valuable in cardiovascular risk stratification in several populations. The current study aims to explore its relation to renal function and its association with traditional cardiovascular risk factors in patients with chronic kidney disease (CKD). Methods Subjects with non-dialysis dependent CKD were recruited and 252 of them had a successful PAT test. In addition to general demographic and medical information, carotid-femoral pulse wave velocity (cfPWV), carotid-radial pulse wave velocity (crPWV) and augmentation index (AIx) were recorded. Results The mean age of the study population was 57.7 (±14.7) years and 155 (61.5%) were males. The average RHI was 1.92 (±14.7) with no difference noted between males and females. There was no statistically significant correlation between RHI and eGFR (r = − 0.107, p = 0.089) or urine protein-to-creatinine ratio (r = 0.036, p = 0.570). With adjustment for age and sex, RHI was associated with systolic blood pressure (BP) (β = 0.006, p = 0.001), diastolic BP (β = 0.008, p = 0.010), heart rate (β = − 0.007, p = 0.015) crPWV (β = 0.037, p = 0.022) and AIx (β = 0.006, p = 0.001), but not with cfPWV or any other conventional risk factors analyzed. Systolic BP remained the only predictor for RHI in the stepwise regression analysis. Conclusions RHI did not decline with reduced renal function in CKD patients and had a modest association with traditional cardiovascular risk factors. Further studies are warranted to determine if RHI could predict cardiovascular outcome in CKD patients.

Abstract Considering the influence of the preferential degree, the hesitation psychology of customers and the heterogeneity of underlying networks in preferential information spreading, we propose a novel model called AHFB (adherent–hesitator–forwarder–beneficiary) model to illustrate the dynamic behaviors of preferential information spreading on scale-free networks. The mean-field theory is adopted to describe the formulas of AHFB model. To begin with, we analyze the spreading dynamics of preferential information. Then we determine the basic reproductive number and equilibria by the next generation matrix method. The relationship among the basic reproductive number, preferential degree, and hesitation parameter is also analyzed. In addition, the globally asymptotical stability of information-eliminate equilibrium and the permanence of the preferential information spreading are proved in detail. Furthermore, a preferential information competition model is proposed, and the corresponding dynamic behaviors are studied. We have found that under certain conditions, a greater competitive advantage can be achieved by improving a certain range of preferential strengths. Numerical simulations are also presented to verify and extend theoretical results.

To investigate the seismic performance of buckling-restrained braces under the earthquake action, the shaking table test with a two-story 1/4 scale model is carried out for the ordinary pure steel frame and the buckling-restrained bracing steel frame with low-yield-point steel as the core plate. The failure modes, dynamic characteristics, acceleration response, interstory drift ratio, strain, shear force, and other mechanical properties of those two comparative structures subjected to different levels of seismic waves are mainly evaluated by the experiment. The test results show that under the action of seismic waves with different intensities, the apparent observations of damage occur in the pure frame structure, while no obvious or serious damage in the steel members of BRB structure is observed. With the increase in loading peak acceleration for the earthquake waves, the natural frequency of both structures gradually decreases and the damping ratio gradually increases. At the end of the test, the stiffness degradation rate of the pure frame structure is 11.2%, while that of the buckling-restrained bracing steel frame structure is only 5.4%. The acceleration response of the buckling-restrained bracing steel frame is smaller than that of the pure steel frame, and the acceleration amplification factor at the second story is larger than that at the first story for both structures. The average interstory drift ratios are, respectively, 1/847 and 1/238 for the pure steel frame under the frequent earthquake and rare earthquake and are 1/3000 and 1/314 for the buckling-restrained bracing steel frame, which reveals that the reduction rate of lateral displacement reaches a maximum of 71.71% after the installation of buckling-restrained brace in the pure steel frame. The strain values at each measuring point of the structural beam and column gradually increase with the increase of the peak seismic acceleration, but the strain values of the pure steel frame are significantly larger than those of the buckling-restrained bracing steel frame, which indicates that the buckling-restrained brace as the first seismic line of defense in the structure can dramatically protect the significant structural members. The maximum shear force at each floor of the structure decreases with the increase in height, and the shear response of the pure frame is apparently higher than that of the buckling-restrained bracing structure.

Objective: A cross-sectional community prevalence survey was conducted to investigate the sero-epidemiological features of hepatitis B virus (HBV) infection among children aged 1–14 years in Guangdong Province in 2013, and to provide baseline data for the evaluation of HBV disease burden and the impacts of HBV control. Methods: A total of 2765 children aged 1–14 years from 16 villages/streets of eight cities in Guangdong Province were recruited as subjects. A blood sample was obtained from each subject. A chemiluminescence microparticle immunoassay (CMIA) was used to detect hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (HBsAb), and antibody to hepatitis B core antigen (HBcAb). Results: The prevalence rates of HBsAg, HBsAb, and HBcAb among children aged 1–14 years were 1.16%, 61.63%, and 2.35%, respectively. The prevalence of HBsAg and HBcAb increased with increasing age, and the prevalence was lowest in the 1–4 years age group (0.97% for HBsAg and 1.45% for HBcAb). In contrast, the prevalence of HBsAb decreased with increasing age; however the prevalence was also highest in the 1–4 years age group (76.48%). Eastern Guangdong had the highest prevalence of HBsAg and HBcAb, and the lowest prevalence of HBsAb. The prevalence of HBsAg was under 1% in the Pearl River Delta and western Guangdong regions. Children who had received three or more doses of vaccine had a lower prevalence of HBsAg and HBcAb and a higher prevalence of HBsAb compared to those who had received fewer than three doses of vaccine. Conclusions: The prevalence of HBsAg among children aged 1–14 years in Guangdong in 2013 was 1.2%, showing a dramatic decrease compared to the 1992 provincial-level cross-sectional survey (19.9%). Children aged 1–4 years and children from the Pearl River Delta had the lowest prevalence of HBsAg positivity. High vaccination coverage among children and timely vaccination of newborns has played an important role in reducing the prevalence of HBsAg.

Abstract Background C-type natriuretic peptide (CNP) is a member of the natriuretic peptide family and have been implicated to be involved in maintaining vascular homeostasis and acting as a cardiac chronotropic agent in experimental studies. However, clinical evidence of its participation in cardiovascular regulation is lacking, especially in patients with chronic kidney disease (CKD). We aimed to explore the association of circulating CNP with cardiovascular alterations in CKD. Methods Seventy-six subjects with CKD were recruited. Plasma CNP-22, the bioactive form of CNP in the circulation, was measured by an enzyme immunoassay. The patients also underwent several cardiovascular evaluations including measurement of blood pressure, endothelial function, heart rate variability (HRV) and pulse wave velocity. Results Mean (±standard deviation) age of the patients were 59.9 (±14.9) years and 56.6% were male. Average plasma CNP level was 790.8 ± 309.1 pg/ml. Plasma CNP level was not increased as estimated glomerular filtration rate declined. There was no significant difference of CNP between patients with or without endothelial dysfunction (with vs. without endothelial dysfunction: 844.6 ± 365.5 pg/ml vs. 738.3 ± 231.8 pg/ml, p = 0.14). Plasma CNP showed no association with blood pressure or pulse wave velocity, but was negatively associated with time-domain HRV parameters (SDNN, RMSSD, Triangular Index). The association of CNP with HRV persisted after adjustment for potential covariates. Conclusions Our data highlights a possible link between circulating CNP and autonomic dysfunction in CKD patients. Further studies are warranted to explore the mechanisms underlying this association, as well as evaluate the ability of circulating CNP in predicting adverse cardiovascular event in CKD patients.

Nowadays, human behaviors are known to spread through social contact. Word-of-mouth (WOM) communication has also become a prevalent strategy for product sales on the internet and most consumers attribute a higher importance to WOM communication. Mathematical modeling is an important approach to study WOM communication in online social networks. In order to investigate the characteristics of WOM communication and heterogeneity of online social networks, a SIALS (susceptible-infected-acknowledged-loath) model is presented on scale-free networks. The spreading dynamics of WOM are analyzed in detail by using the theory of mean field. The basic reproductive number R0 is calculated by the next generation matrix method and two equilibriums are derived. The theoretical analysis indicates that the basic reproductive number depends mainly on the transmission of WOM and the topology of the underlying networks. Furthermore, the global stability of the WOM-disappearance equilibrium is proved. The permanence of WOM information spreading and the global attractivity of the WOM-prevailing equilibrium are also studied in detail. Finally, numerical simulations confirm the analytical results.

Abstract Background Adipokines are a set of cytokines secreted by white adipose tissue that have been suggested to be involved in the development of cardiovascular diseases. We aimed to evaluate the cross-sectional associations of a panel of representative adipokines with cardiovascular measures in a cohort of hemodialysis patients. Methods We measured plasma adiponectin, resistin, plasminogen activator inhibitor-1 (PAI-1), leptin, monocyte chemotactic protein 1 (MCP-1) and adipsin levels in 366 dialysis patients and 60 healthy controls. The associations of these adipokines with systolic blood pressure (assessed by ambulatory blood pressure monitoring), pulse wave velocity (PWV) and cardiac markers (BNP, NT-proBNP, Troponin I, Troponin T) in these patients were determined by general linear models with stepwise adjustment for covariates. Results In unadjusted comparison with controls, dialysis patients showed increased adiponectin, resistin, MCP-1 and adipsin levels, decreased PAI-1 concentrations (all p

Impact cratering experiments were performed on semi-infinite concrete targets with 7 mm-diameter 40CrNiMo steel long-rod projectiles at impact velocities ranging from 2117 m/s to 3086 m/s by using a two-stage combustion light-gas gun. After the impact experiments, the crater diameter and depth as well as the crater volume were carefully measured. The concrete fragments were collected from the target chamber and the fragment mass was measured. The size of the crater (including the volume, diameter, and depth) and the fragment mass increased with increasing impact velocities, while the fragment distributions at different impact velocities were almost the same. Scaling laws for the crater volume impacted by the rod-shaped projectile were discussed and an empirical formula of crater volume was determined by the experimental data from the literature. Through the verification of the present experimental results, the predictive ability of the empirical formula proved to be reliable. Scaling laws for the size distribution of concrete fragments were also discussed. The normalized fragment mass distribution was proportional to the impact velocity raised to the power 1.5.

Three types of multi-wall shielding were experimentally investigated for their performances under the high-velocity impact of a cm-size cylindrical projectile by using a two-stage light-gas gun. The three shields contained the same two aluminum bumpers but different rear walls, which were 7075-T651 aluminum (Al) plate, boron carbide (B4C)/Al 7075-T651/Kevlar composite plate and B4C/ultra-high molecular weight polyethylene (UHMW-PE) composite plate. The impact test was carried out using a cylindrical shape of 6 g mass 7075-T651 Al projectile in a speed range (1.6 to 1.9 km/s) to achieve an effective shield configuration. A numerical simulation was undertaken by using ANSYS Autodyn-3D and the results of this were in good agreement with the experimental results. Meanwhile, both the experimental and the numerical simulation results indicated that B4C/UHMW-PE composite plates performed a better interception of the high-velocity projectiles within the specific speed range and could be considered as a good configuration for intercepting large fragments in shielding design.

The structure of cucurbit[6]uril (CB[6]), as a fascinating supramolecular receptor, is regarded as ‘indestructible’. Herein, we investigated the hydrolysis of CB[6] catalysed by alkali. Our results showed that CB[6] was easily hydrolysed in 30% NaOH at 160°C within 3 h. Separation and purification of hydrolytic products demonstrated the presence of NH3, CO2, HCOONa, glycine and hydantoic acid. Based on the studies of the hydrolysis of substances similar to CB[6] including 4,5-dihydroxyethyleneurea, glycoluril and glycoluril dimer, we proposed that a plausible reaction mechanism involved a Cannizzaro reaction, which is supported by HPLC, mass spectrometry data and previous reports. Further studies are dedicated towards a controlled hydrolysis of CB[6], which will provide a new route for direct functionalization of CB[6].

High-entropy alloys have been recently found to have novel microstructures and unique properties. In this study, a novel Al𝑋FeCoNiCuCr high-entropy alloy was prepared by laser cladding. The microstructure, chemical composition, and constituent phases of the synthesized alloy were characterized by SEM, EDS, XRD, and TEM, respectively. High-temperature hardness was also evaluated. Experimental results demonstrate that the Al𝑋FeCoNiCuCr clad layer is composed of only BCC and FCC phases. The clad layers exhibit higher hardness at higher Al atomic content. The AlFeCoNiCuCr clad layer exhibits increased hardness at temperature between 400–700°C.

To address the stressful and time-consuming problem with the current notched antenna modelling optimization tools, an improved deep multilayer perceptron (DMLP) neural network framework is designed. The method introduces an attention mechanism (Attn) layer to improve the interpretability of the model, uses the leaky ReLU activation function to prevent the gradient from vanishing, and optimizes the structure of the DMLP model using an improved particle swarm algorithm (PSO) to improve the model prediction accuracy. Then, the notch structure geometric parameters of the designed double-notch ultra-wideband (UWB) antenna serve as input to predict the return loss S11 of the antenna. The experimental results show that the method reduces the root mean square error of prediction for S11 by 73.01% compared to the traditional MLP and 64.14% compared to the unimproved DMLP, which provides a solution for modelling notched UWB antennas and helps to optimize the design of this type of antenna. [ABSTRACT FROM AUTHOR]