•A new Peridynamic model for functionally graded materials;•Crack curving and branching in FGMs under dynamic loads.•The influence of the Gradient forms on the crack propagating in the FGMs plate ...under biaxial loads.
In this study, a bond-based peridynamic (PD) model for functionally graded materials (FGMs) was introduced to simulate various dynamic brittle fractures in FGMs. The PD analyses of dynamic crack propagation and branching in FGMs were discussed, and the results of the two convergence studies under uniform grid refinement (m-convergence) and decreasing radius of PD horizon (δ-convergence) were presented. The influence of material gradient pattern on crack curving and branching in FGMs under dynamic loads was analyzed. In addition, the propagation of a single crack in FGMs subjected to dynamic biaxial loads was studied. The effects of loading conditions and gradient patterns of FGMs were investigated. The results of these investigations suggest that both the material gradient patterns and the loading conditions can affect the crack propagation in FGMs, whereas the influence of a specific form of elastic modulus on the fracture behavior of FGMs is limited.
Hybrid CdS/MoS
2
with branch and leaf shaped structures are successfully synthesized by hydrothermal method. It is applied to detect volatile organic compounds, a basic source of indoor air pollution ...with deleterious effects on the human health. The sensor based on CdS/MoS
2
displays an outstanding response to alcohols among numerous gases. Their response to 100 ppm ethanol and isopropanol reaches 56 and 94, respectively. Benefiting from the dendrite-like biomimetic structure and synergy effect of CdS and MoS
2
, the sensor exhibits higher response than traditional gas sensor. For multiple alcohols, the limit of detection reached ppb level. In addition, by comparing the response of ethanol, isopropanol, isoamyl alcohol and their mixtures with acetone and methanal, a strong resistance interference is observed. This work proved that the modified detector holds broad promise in the detection of alcohols.
The structural, electronic, and optical properties of Cu
2
XSnS
4
(X = Be, Mg, Ca, Cd, Hg) were investigated through first-principles calculations based on density-functional theory combined with the ...Hubbard
U
parameter. Cu
2
XSnS
4
is a class of p-type direct band-gap semiconductors with band gaps ranging from 1.05 to 2.11 eV, isotropic effective electron masses, and anisotropic effective hole masses. Notably, Cu
2
HgSnS
4
exhibits the average electron and hole effective masses of 0.096 and 0.216
m
0
, respectively, which are lower than those of Cu
2
ZnSnS
4
. According to the absorption spectra, the absorption coefficient of Cu
2
XSnS
4
exceeds 10
4
cm
−1
, with Cu
2
HgSnS
4
exhibiting a higher average absorption coefficient compared to Cu
2
ZnSnS
4
. These findings indicate that Cu
2
HgSnS
4
is the promising material for solar cell applications.
In the present study, an integrated framework for automatic detection, segmentation, and measurement of road surface cracks is proposed. First, road images are captured, and crack regions are ...detected based on the fifth version of the You Only Look Once (YOLOv5) algorithm; then, a modified Residual Unity Networking (Res-UNet) algorithm is proposed for accurate segmentation at the pixel level within the crack regions; finally, a novel crack surface feature quantification algorithm is developed to determine the pixels of crack in width and length, respectively. In addition, a road crack dataset containing complex environmental noise is produced. Different shooting distances, angles, and lighting conditions are considered. Validated through the same dataset and compared with You Only Look at CoefficienTs ++ (YOLACT++) and DeepLabv3+, the proposed method shows higher accuracy for crack segmentation under complex backgrounds. Specifically, the crack damage detection based on the YOLOv5 method achieves a mean average precision of 91%; the modified Res-UNet achieves 87% intersection over union (IoU) when segmenting crack pixels, 6.7% higher than the original Res-UNet; and the developed crack surface feature algorithm has an accuracy of 95% in identifying the crack length and a root mean square error of 2.1 pixels in identifying the crack width, with the accuracy being 3% higher in length measurement than that of the traditional method.
Flavanols, a common class of secondary plant metabolites, exhibit several beneficial health properties by acting as antioxidant, anticarcinogen, cardioprotective, anti-microbial, anti-viral, and ...neuroprotective agents. Furthermore, some flavanols are considered functional ingredients in dairy products. Based on their structural features and health-promoting functions, flavanols have gained the attention of pharmacologists and botanists worldwide. This review collects and summarizes 121 flavanols comprising four categories: flavan-3-ols, flavan-4-ols, isoflavan-4-ols, and flavan-3,4-ols. The research of the various structural features and pharmacological activities of flavanols and their derivatives aims to lay the groundwork for subsequent research and expect to provide mentality and inspiration for the research. The current study provides a starting point for further research and development.
Bi
2
WO
6
flower-like materials (FMs) were prepared by a hydrothermal method, followed by an in-situ reduction method to prepare Au@Bi
2
WO
6
FMs. X-ray diffraction, scanning electron microscopy, ...transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy were employed to characterize the samples. It was discovered that the calculated O
V
content of Au@Bi
2
WO
6
FMs is 25.16% whereas that of Bi
2
WO
6
FMs is 20.81%, offering appropriate active sites for the absorption of gases and thus enhancing outstanding sensing property. Moreover, the detection of volatile and hazardous substances such as formaldehyde, methanol, acetone, benzene, toluene, and xylene was carried out to assess the efficacy of the Au@Bi
2
WO
6
FMs sensors. The optimal operating temperatures for the Bi
2
WO
6
FMs and Au@Bi
2
WO
6
FMs sensors were 290 and 260 °C, respectively. Compared with Au@Bi
2
WO
6
FMs sensor and Bi
2
WO
6
FMs one, the best response of the front was 250 (900)–100 (800) ppm formaldehyde whereas that of the latter was 90 (230). Therefore, Au@ Bi
2
WO
6
FMs have good response and selectivity, which are promising candidates for formaldehyde detection.
We report on the studies of strong exciton photon coupling and polariton lasing at room temperature from single GaN microrods grown by metal-organic vapor phase epitaxy technique. Emission spectra ...were recorded at room temperature by exciting GaN microrods with pulsed Nd:YAG laser of 355 nm wavelength at different excitation power density. Clear mode formation corresponding to Whispering gallery modes in GaN microrod cavity has been observed. Strong exciton–photon coupling as well as large Rabi splitting energy of maximum 400 ± 40 meV has been observed from the microrods. This is attributed to the formation of new quasi-particles named polaritons with much lighter mass than free electron mass. Among those polariton modes, one of the modes increases super linearly with the increase in excitation power density which is an indication of polariton lasing.
For real-application gas sensors, high performances (response, selectivity, response/recovery time and stability) are demanded. An effective strategy is applying nanomaterials in gas sensors. In this ...study, the anatase TiO
2
flower-like nanomaterials (FLNMs) are prepared through a one-step hydrothermal method which exhibit high-performance toward acetone vapor. TiO
2
FLNMs sensors property are characterized at optimal working temperature of 330 °C with selectivity (acetone), response (
S
= 33.72 toward 250 ppm acetone), linear dependence (
R
2
= 0.9913), response/recovery time (46/24 s toward 250 ppm acetone) and long-term stability (30 days). These demonstrate that TiO
2
FLNMs get a high performance for acetone sensor. Moreover, the limit of detection of acetone is 0.65 ppm which is lower than that of exhaled air for diabetes (0.8 ppm), indicating that TiO
2
FLNMs gas sensor gets potential application in medical diagnosis.
There remain gaps in quantifying mortality risk among individuals co-infected with chronic hepatitis B (HBV) and human immunodeficiency virus (HIV) in sub-Saharan African contexts. Among a cohort of ...HIV-positive individuals in Rwanda, we estimate the difference in time-to mortality between HBV-positive (HIV/HBV co-infected) and HBV-negative (HIV mono-infected) individuals.
Using a dataset of HIV-infected adults screened for hepatitis B surface antigen (HBsAg) from January to June 2016 in Rwanda, we performed time-to-event analysis from the date of HBsAg results until death or end of study (31 December 2019). We used the Kaplan-Meier method to estimate probability of survival over time and Cox proportional hazard models to adjust for other factors associated with mortality.
Of 21,105 available entries, 18,459 (87.5%) met the inclusion criteria. Mean age was 42.3 years (SD = 11.4) and 394 (2.1%) died during follow-up (mortality rate = 45.7 per 100,000 person-months, 95% confidence interval (CI) 41.4-50.4) Mortality rate ratio for co-infection was 1.7, 95% CI 1.1-2.6, however, Cox regression analysis did not show any association with mortality between compared groups. The adjusted analysis of covariates stratified by co-infection status showed that males, residing outside of the capital Kigali, drinking alcohol, WHO-HIV-clinical stage 3 and 4 were associated with increased mortality in this HIV cohort.
HBV infection does not significantly influence mortality among HIV-infected individuals in Rwanda. The current cohort is likely to have survived a period of high-risk exposure to HBV and HIV mortality and limited health care until their diagnosis.
Uncovering genetic variation through resequencing is limited by the fact that only sequences with similarity to the reference genome are examined. Reference genomes are often incomplete and cannot ...represent the full range of genetic diversity as a result of geographical divergence and independent demographic events. To more comprehensively characterize genetic variation of pigs (
), we generated de novo assemblies of nine geographically and phenotypically representative pigs from Eurasia. By comparing them to the reference pig assembly, we uncovered a substantial number of novel SNPs and structural variants, as well as 137.02-Mb sequences harboring 1737 protein-coding genes that were absent in the reference assembly, revealing variants left by selection. Our results illustrate the power of whole-genome de novo sequencing relative to resequencing and provide valuable genetic resources that enable effective use of pigs in both agricultural production and biomedical research.
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