Woven lattice truss sandwich panels (WLTSPs) structure has excellent anti-stripping ability and energy absorption effect. The warp and weft distributions have an effect on the WLTSPs. Foam-filling ...technique and different heights of WLTSPs were double studied by the testing. Through the compression test and lateral compression test reveal the deformation, damage, failure and energy absorption. In the compression testing, the foam-filling can effectively increase peak force (PF) and energy absorption (EA), especially the weft distribution along the length direction-the specific energy absorption per unit mass of foam (△SEA) is 7.086 J/g. The foam filling transforms the piles from compression-shear coupled damage to progressive damage. In the lateral compression testing, when the WLTSPs at a low height the foam filling leads the load-displacement curve changes from brittleness to ductility. Foam filling improves the PF of PB by up to 459% at the height of 80 mm and restrain the decrease of bearing capacity with the increased height. The failure modes of the WLTSPs includes bending failure to progressive failure, concave, and the end fracture compression.
•Foam filling technology has an effect on the performance and energy absorption of WLTSPs.
Solvothermal method is used to obtain N-doped graphene hydrogels (NGHs) using hydroxylamine hydrochloride or hydroxylamine (HA) as the chemical reductant and dopant. During the process, N-doping and ...reduction of graphene oxide have been achieved simultaneously. The products have been characterized by X-ray diffraction, X-ray photoelectron, Raman spectroscopy and electrochemistry. The results show that the electrical conductivity, microstructure and doping level of NGHs are influenced by the type and quantity of reductants, temperature and time of the reaction. Their capacitive behavior has been investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in an alkaline electrolyte using the two-electrode symmetric capacitor test. The NGHs prepared at 150 °C for 12 h using HA as reductant (NGH–HA12) has N-doping level of 4.32% in atom and exhibits a specific capacitance of 205 F g−1 and good cycling stability. The energy density and power density can reach to 3.65 W h kg−1 and 20.5 kW kg−1 at a discharge of 100 A g−1 for the symmetric capacitor assembled using NGH–HA12.
•N-doped graphene hydrogels (NGHs) were prepared by thermally treating graphene oxide.•The optimum conditions were determined by using hydroxylamine as reducing agent.•The capacitor assembled by the optimum NHGs exhibit good capacitive performance.
Epidemiological evidence of short-term fine particulate matter (PM2.5) exposure on blood pressure (BP), heart rate (HR) and related inflammation biomarkers has been inconsistent. We aimed to explore ...the acute effect of PM2.5 on BP, HR and the mediation effect of related inflammation biomarkers. A total of 32 healthy college students were recruited to perform 4 h of exposure at two sites with different PM2.5 concentrations in Wuhan between May 2019 and June 2019. The individual levels of PM2.5 concentration, BP and HR were measured hourly for each participant. Blood was drawn from each participant after each visit and we measured the levels of inflammation markers, including serum high-sensitivity C-reactive protein and plasma fibrinogen. Linear mixed-effect models were to explore the acute effect of PM2.5 exposure on BP, HR, and related inflammation biomarkers. In addition, we evaluated related inflammation biomarkers as the mediator in the association of PM2.5 and cardiovascular health indicators. The results showed that a 10 μg/m3 increment in PM2.5 concentration was associated with an increase of 0.84 (95% CI: 0.54, 1.15) beats/min (bpm) in HR and a 3.52% (95% CI: 1.60%, 5.48%) increase in fibrinogen. The lag effect model showed that the strongest effect on HR was observed at lag 3 h of PM2.5 exposure 1.96 bpm (95% CI: 1.19, 2.75), but for fibrinogen, delayed exposure attenuated the association. Increased fibrinogen levels may account for 39.07% (P = 0.44) of the elevated HR by PM2.5. Null association was observed when it comes to short-term PM2.5 exposure and BP. Short-term exposure to PM2.5 was associated with elevated HR and increased fibrinogen levels. But our finding was not enough to suggest that exposure to PM2.5 might induce adverse cardiovascular effects by the pathway of inflammation.
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•PM2.5 exposure is a risk factor for cardiovascular diseases.•Personal exposure to PM2.5 for a short term can elevate heart rate and fibrinogen levels.•The role of inflammation in PM2.5-induced cardiovascular effects was explored.
Localized surface plasmon resonance (LSPR)-based sensors exhibit enormous potential in the areas of medical diagnosis, food safety regulation and environmental monitoring. However, the broadband ...spectral lineshape of LSPR hampers the observation of wavelength shifts in sensing processes, thus preventing its widespread applications in sensors. Here, we describe an improved plasmonic sensor based on Fano resonances between LSPR and the Rayleigh anomaly (RA) in a metal-insulator-metal (MIM) meta-grating, which is composed of silver nanoshell array, an isolation grating mask and a continuous gold film. The MIM configuration offers more freedom to control the optical properties of LSPR, RA and the Fano resonance between them. Strong couplings between LSPR and RA formed a series of narrowband reflection peaks (with a linewidth of ~20 nm in full width at half maximum (FWHM) and a reflectivity nearing 100%) within an LSPR-based broadband extinction window in the experiment, making the meta-grating promising for applications of high-efficiency reflective filters. A Fano resonance that is well optimized between LSPR and RA by carefully adjusting the angles of incident light can switch such a nano-device to an improved biological/chemical sensor with a figure of merit (FOM) larger than 57 and capability of detecting the local refractive index changes caused by the bonding of target molecules on the surface of the nano-device. The figure of merit of the hybrid sensor in the detection of target molecules is 6 and 15 times higher than that of the simple RA- and LSPR-based sensors, respectively.
Breast Ultrasound (BUS) imaging is an essential tool for the early detection of breast cancer. The Breast Imaging Reporting and Data System (BI-RADS) in BUS images helps standardize the ...interpretation and reporting process by categorizing breast tumors into multiple classes, which enables radiologists to make more accurate diagnoses and treatment plans. However, most existing classification methods distinguish only between benign and malignant categories. In addition, features extracted by classic convolutional neural networks tend to be insufficient when subdividing BUS images into fine-grained BI-RADS classes, as they typically do not consider prior knowledge in medical applications, such as foreground shape. To address the above problems, we propose a novel fine-grained BI-RADS classification approach that integrates tumor edges to provide more efficient discriminative features. Firstly, weakly supervised pseudo-label generation: we detect coarse tumor edge regions utilizing a pre-trained PiDiNet and two novel loss functions based on prior knowledge from our dataset. The detected tumor edges are subsequently used as pseudo-labels for the next step. Secondly, co-training a tumor edge detection network and a BI-RADS classification network: edge images generated by the edge detection network are used as weight masks to highlight tumor edge regions as discriminative parts for better classification results, especially for categories with high similarities. The proposed method is evaluated on a BUS image dataset of 1061 images with BI-RADS categories. Experimental results indicate that the proposed method significantly improves over the baseline model by 4.73% in terms of top-1 accuracy.
The mesoporous carbon nanofibers (MCFs) with large cage-like pores have been fabricated by thermally treating electrospun fibers of polyvinyl alcohol containing tin compound. During the process, tin ...oxide is reduced to melting tin and the carbon is activated to form the porous carbon. The results of X-ray diffraction and transmission electron microscopy at different temperatures show that particles of SnO2 (∼1.9nm) exist in the fibers at 300°C while mixtures of Sn and SnO with rod-like shapes appear in the matrix when the fibers are heated at 400°C, and that Sn migrates to the surface of fibers and pores are formed in the fibers at higher temperature. Specific surface area of MCFs can reach 800m2g−1 and the average diameter of interior pores is about 10.3nm while the entrance pores are small. The specific capacitance of MCFs is 105Fg−1 and the fabricated symmetrical capacitors exhibit high-rate capacitive properties and excellent stability, Pt nanoparticles which can be densely loaded on MCFs exhibit relatively high activity and stability toward electro-oxidation of methanol, which indicate that MCFs may be used as electrodes for high-rate energy storage and support for catalyst. This approach may be extended to prepare other porous carbon materials.
Abstract
Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying ...microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (
Q
10
) in a temperate grassland ecosystem persistently decreases by 12.0 ± 3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5–19%, and reduces model parametric uncertainty by 55–71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6 ± 7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.
In this paper, a numerical model of hydrological and hydrodynamic processes—GAST model (GPU Accelerated Surface Water Flow and Associated Transport) is introduced to simulate the runoff control ...effect of rain garden based on a two-dimensional dynamic wave method. After validation with an experimental rain garden and a real rain garden in a sponge community, the results indicated a good agreement between simulated process of water growth and measured results. The RMSE values of 0.00084 and 0.1809 were less than half of the standard deviation of the simulated values, which showed that the model had a good performance and it was an ideal tool for the runoff control effect simulation in a single bioretention facility. Additionally, the results simulated by GAST model and SWMM model were compared with the measured results. For GAST model, the RMSE was 0.1809, and for SWMM model, the RMSE was 0.5226. It meant that GAST model had a higher accuracy in this test case. This model was also used to study the runoff control rules of rain garden at different return periods. The results showed that when the ponding depth was 15 cm and the flow area ratio was 15:1, the shorter the return period was, the greater the runoff-control rate was. The runoff-control rate of rain garden was 31.89%–100% for 0.5a to 50a. When the return period was shorter, the difference of the runoff-control rate was greater, and it was the opposite when the return period was longer. For example, the runoff-control rate was 53.02%–100% for the 0.5a to 5a inflow conditions, and the difference of the control rates between 1a and 2a was 25.79%, while the runoff-control rate for the return periods of 5a and 50a was 31.89%–53.02%, of which the difference between 10a and 20a control rates was only 4.30%.
This study reviewed the prediction of fine particulate matter (PM2.5) from satellite aerosol optical depth (AOD) and summarized the advantages and limitations of these predicting models. A total of ...116 articles were included from 1436 records retrieved. The number of such studies has been increasing since 2003. Among these studies, four predicting models were widely used: Multiple Linear Regression (MLR) (25 articles), Mixed-Effect Model (MEM) (23 articles), Chemical Transport Model (CTM) (16 articles) and Geographically Weighted Regression (GWR) (10 articles). We found that there is no so-called best model among them and each has both advantages and limitations. Regarding the prediction accuracy, MEM performs the best, while MLR performs worst. CTM predicts PM2.5 better on a global scale, while GWR tends to perform well on a regional level. Moreover, prediction performance can be significantly improved by combining meteorological variables with land use factors of each region, instead of only considering meteorological variables. In addition, MEM has advantages in dealing with the AOD data with missing values. We recommend that with the help of higher resolution AOD data, future works could be focused on developing satellite-based predicting models for the prediction of historical PM2.5 and other air pollutants.
The geological units in Shandong Province, North China are important parts of the North China Craton and offer important insights into their crustal evolutionary history. This work compiled 611 sets ...of Nd isotopic data of Archean-Mesozoic rocks from Shandong including the Luxi, Jiaobei, and Sulu terranes, which provided important constraints for crustal growth and reactivation. Nd-depleted mantle model ages (
T
DM
) of Archean rocks with positive
ε
Nd
(
t
) values showed that ca. 2.9 and 2.8-2.7 Ga were the most important periods of crustal growth in the Jiaobei and Luxi terranes, respectively, while the period of ca. 2.6-2.5 Ga in the Jiaobei terrane likely indicated a coherent event of crustal growth and reworking. During the Proterozoic, multi-stage rifting and collisional orogenic events possibly led to the reworking of Archean crust in the source region. The Nd isotopic data of the Paleoproterozoic and Neoproterozoic rocks from Sulu indicated significant reworking of older crust with juvenile magmatic input. Crustal reactivation occurred during the Mesozoic. The younger
T
DM
ages of the Mesozoic rocks with low negative
ε
Nd
(
t
) values indicated that a juvenile crustal/mantle component was added to the ancient basement. The reactivation reflected significant crust-mantle interaction via the mechanism of crustal subduction and mantle-derived magma un-derplating, or possibly asthenospheric upwelling. Our work also attempted to establish the crustal correlation between Shandong and Korea (including the Gyeonggi massif, Ogcheon belt, and Yeongnam massif). The
T
DM
age distribution provided evidence favoring the affinity relationship between the Gyeonggi massif and Ogcheon belt of South Korea and the Jiaobei and Sulu terranes of Shandong, while the Yeongnam massif was more correlated with the South China Block.
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