Background: Off-pump coronary artery bypass grafting (OPCAB) is a surgical procedure that has gained popularity due to its potential benefits over traditional coronary artery bypass grafting, including reduced morbidi...Background: Off-pump coronary artery bypass grafting (OPCAB) is a surgical procedure that has gained popularity due to its potential benefits over traditional coronary artery bypass grafting, including reduced morbidity and mortality. However, sternal wound complication (SWC) remains challenging following the procedure. The technique of left internal mammary artery (LIMA) harvesting has been shown to impact the incidence of SWC. This study aimed to compare the incidence of SWC between two techniques of LIMA harvesting, i.e., skeletonized and pedicled. Methods: The study was conducted at the Department of Cardiac Surgery, Bangabandhu Sheikh Mujib Medical University, and included 60 patients who underwent OPCAB. The patients were divided into two groups of 30 each based on the technique of LIMA harvesting used, i.e., skeletonized (group A) or pedicled (group B). The postoperative ICU care was given to each patient as per the protocol. The statistical analysis was conducted using the SPSS version 26.0 for Windows software. Results: The results showed that 5 (8.33%) patients developed SWC, with 1 (1.67%) patient in group A and 4 (6.66%) patients in group B. However, the occurrence of SWC was not statistically significant between the two groups (p = 0.35). The mean age, gender distribution, and comorbidities such as hypertension, diabetes, dyslipidemia, and anemia were also not statistically significant between the two groups. The number of smokers was statistically significant between the two groups (p = 0.03), and the occurrence of SWC was found to be higher in smoker patients in group B (p = 0.04). Preoperative and postoperative parameters such as duration of operation, duration of mechanical ventilation, duration of chest drains, duration of the central venous line, and amount of postoperative mediastinal bleeding were also not statistically significant between the two groups. The distribution of wound complications, duration of ICU stays, and hospital stay between the two groups was also not statistically significant. Conclusion: In conclusion, this study found that the incidence of SWC was less in skeletonized LIMA harvesting than in pedicled LIMA harvesting after OPCAB. However, this finding was not statistically significant. Further studies with larger sample sizes may be needed to confirm these results and determine the appropriate technique of LIMA harvesting to decrease the incidence of SWC after OPCAB.展开更多
The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected u...The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected using the skeletonization technique. In the group Ⅱ(n=50), the ITA was harvested as a pedicled graft. Free flow of the ITA was recorded before and 15 min after in- traluminal application of diluted papaverine. Mean arterial pressure was maintained at 9. 31 kPa (70 mmHg). The results showed that before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine, the maximum free flow was significantly higher in the skeletonized ITA's in the group Ⅰ(199. 3±69. 6 ml/min) than in the group Ⅱ(145. 7±70. 3 ml/min, P<0. 05). There was on significant differ- ence between the free flow after dilatation of the left and right ITA in the group Ⅰ (left 199. 3±69. 6 ml/mm, right 198. 9±61. 8 ml/mm, respectively). It was concluded that preparation of the ITA with the skeletonization technique resulted in significantly higher free flow capacity than in pedicled grafts and would improve the results of arterial revascularization. The complication rate seems to be lower than with the conventional method.展开更多
The Internet of Things(IoT)and mobile technology have significantly transformed healthcare by enabling real-time monitoring and diagnosis of patients.Recognizing Medical-Related Human Activities(MRHA)is pivotal for he...The Internet of Things(IoT)and mobile technology have significantly transformed healthcare by enabling real-time monitoring and diagnosis of patients.Recognizing Medical-Related Human Activities(MRHA)is pivotal for healthcare systems,particularly for identifying actions critical to patient well-being.However,challenges such as high computational demands,low accuracy,and limited adaptability persist in Human Motion Recognition(HMR).While some studies have integrated HMR with IoT for real-time healthcare applications,limited research has focused on recognizing MRHA as essential for effective patient monitoring.This study proposes a novel HMR method tailored for MRHA detection,leveraging multi-stage deep learning techniques integrated with IoT.The approach employs EfficientNet to extract optimized spatial features from skeleton frame sequences using seven Mobile Inverted Bottleneck Convolutions(MBConv)blocks,followed by Convolutional Long Short Term Memory(ConvLSTM)to capture spatio-temporal patterns.A classification module with global average pooling,a fully connected layer,and a dropout layer generates the final predictions.The model is evaluated on the NTU RGB+D 120 and HMDB51 datasets,focusing on MRHA such as sneezing,falling,walking,sitting,etc.It achieves 94.85%accuracy for cross-subject evaluations and 96.45%for cross-view evaluations on NTU RGB+D 120,along with 89.22%accuracy on HMDB51.Additionally,the system integrates IoT capabilities using a Raspberry Pi and GSM module,delivering real-time alerts via Twilios SMS service to caregivers and patients.This scalable and efficient solution bridges the gap between HMR and IoT,advancing patient monitoring,improving healthcare outcomes,and reducing costs.展开更多
In recent years,gait-based emotion recognition has been widely applied in the field of computer vision.However,existing gait emotion recognition methods typically rely on complete human skeleton data,and their accurac...In recent years,gait-based emotion recognition has been widely applied in the field of computer vision.However,existing gait emotion recognition methods typically rely on complete human skeleton data,and their accuracy significantly declines when the data is occluded.To enhance the accuracy of gait emotion recognition under occlusion,this paper proposes a Multi-scale Suppression Graph ConvolutionalNetwork(MS-GCN).TheMS-GCN consists of three main components:Joint Interpolation Module(JI Moudle),Multi-scale Temporal Convolution Network(MS-TCN),and Suppression Graph Convolutional Network(SGCN).The JI Module completes the spatially occluded skeletal joints using the(K-Nearest Neighbors)KNN interpolation method.The MS-TCN employs convolutional kernels of various sizes to comprehensively capture the emotional information embedded in the gait,compensating for the temporal occlusion of gait information.The SGCN extracts more non-prominent human gait features by suppressing the extraction of key body part features,thereby reducing the negative impact of occlusion on emotion recognition results.The proposed method is evaluated on two comprehensive datasets:Emotion-Gait,containing 4227 real gaits from sources like BML,ICT-Pollick,and ELMD,and 1000 synthetic gaits generated using STEP-Gen technology,and ELMB,consisting of 3924 gaits,with 1835 labeled with emotions such as“Happy,”“Sad,”“Angry,”and“Neutral.”On the standard datasets Emotion-Gait and ELMB,the proposed method achieved accuracies of 0.900 and 0.896,respectively,attaining performance comparable to other state-ofthe-artmethods.Furthermore,on occlusion datasets,the proposedmethod significantly mitigates the performance degradation caused by occlusion compared to other methods,the accuracy is significantly higher than that of other methods.展开更多
Previous multi-view 3D human pose estimation methods neither correlate different human joints in each view nor model learnable correlations between the same joints in different views explicitly,meaning that skeleton s...Previous multi-view 3D human pose estimation methods neither correlate different human joints in each view nor model learnable correlations between the same joints in different views explicitly,meaning that skeleton structure information is not utilized and multi-view pose information is not completely fused.Moreover,existing graph convolutional operations do not consider the specificity of different joints and different views of pose information when processing skeleton graphs,making the correlation weights between nodes in the graph and their neighborhood nodes shared.Existing Graph Convolutional Networks(GCNs)cannot extract global and deeplevel skeleton structure information and view correlations efficiently.To solve these problems,pre-estimated multiview 2D poses are designed as a multi-view skeleton graph to fuse skeleton priors and view correlations explicitly to process occlusion problem,with the skeleton-edge and symmetry-edge representing the structure correlations between adjacent joints in each viewof skeleton graph and the view-edge representing the view correlations between the same joints in different views.To make graph convolution operation mine elaborate and sufficient skeleton structure information and view correlations,different correlation weights are assigned to different categories of neighborhood nodes and further assigned to each node in the graph.Based on the graph convolution operation proposed above,a Residual Graph Convolution(RGC)module is designed as the basic module to be combined with the simplified Hourglass architecture to construct the Hourglass-GCN as our 3D pose estimation network.Hourglass-GCNwith a symmetrical and concise architecture processes three scales ofmulti-viewskeleton graphs to extract local-to-global scale and shallow-to-deep level skeleton features efficiently.Experimental results on common large 3D pose dataset Human3.6M and MPI-INF-3DHP show that Hourglass-GCN outperforms some excellent methods in 3D pose estimation accuracy.展开更多
As a natural alkaloid found extensively in cereal crops, gramine not only plays a crucial role in protecting barley and other grasses from various pests, but also reduces palatability for ruminants. Scientists are try...As a natural alkaloid found extensively in cereal crops, gramine not only plays a crucial role in protecting barley and other grasses from various pests, but also reduces palatability for ruminants. Scientists are trying to figure out how gramine gets into cereal plants: is it inherently present or transformed through a special process? The latest study published in Science by Sara Leite Dias and co-authors, provides a detailed explanation. The starting point of the transformation is identified, and the transformation process is confirmed through rigorous experiments.展开更多
Two novel skeleton sesquiterpenoids(1 and 6),along with four new iphionane-type sesquiterpenes(2−5)and six new cyperane-type sesquiterpenes(7−11),were isolated from the whole plant of Artemisia hedinii(A.hedinii).The ...Two novel skeleton sesquiterpenoids(1 and 6),along with four new iphionane-type sesquiterpenes(2−5)and six new cyperane-type sesquiterpenes(7−11),were isolated from the whole plant of Artemisia hedinii(A.hedinii).The two novel skeleton compounds(1 and 6)were derived from the decarbonization of iphionane and cyperane-type sesquiterpenes,respectively.Their structures were elucidated through a comprehensive analysis of spectroscopic data,including high-resolution electrospray ionization mass spectrometry(HR-ESI-MS)and 1D and 2D nuclear magnetic resonance(NMR)spectra.The absolute configurations were determined using electronic circular dichroism(ECD)spectra,single-crystal X-ray crystallographic analyses,time-dependent density functional theory(TDDFT)ECD calculation,density functional theory(DFT)NMR calculations,and biomimetic syntheses.The biomimetic syntheses of the two novel skeletons(1 and 6)were inspired by potential biogenetic pathways,utilizing a predominant eudesmane-type sesquiterpene(A)in A.hedinii as the substrate.All compounds were evaluated in LX-2 cells for their anti-hepatic fibrosis activity.Compounds 2,8,and 10 exhibited significant activity in downregulating the expression ofα-smooth muscle actin(α-SMA),a protein involved in hepatic fibrosis.展开更多
A category of highly fused diterpenoid natural products possessing a characteristic perhydropyrene-like or rearranged tetracyclic skeleton structure are distributed in different life forms.Compared to traditional poly...A category of highly fused diterpenoid natural products possessing a characteristic perhydropyrene-like or rearranged tetracyclic skeleton structure are distributed in different life forms.Compared to traditional polycyclic diterpenoids,their biosynthetic pathways are quite unique and diverse.Chemists have pinpointed a range of this type of unusual diterpenoids:cycloamphilectanes and isocycloamphilectanes,kempenes and rippertanes,hydropyrene and hydropyrenol,along with recently disclosed cephalotanes.This review describes developments in this field and discusses the challenges associated with synthesizing this class of highly complex compounds.展开更多
The environments of tropical and subtropical coral reef regions(CRR)differ from each other;however,it is not known if these environmental differences influence coral polyp and skeleton microbiome composition.In this s...The environments of tropical and subtropical coral reef regions(CRR)differ from each other;however,it is not known if these environmental differences influence coral polyp and skeleton microbiome composition.In this study,Coelastrea palauensis corals were collected from tropical and subtropical CRR in the South China Sea,and bacterial,archaeal,and fungal communities in polyps and skeletons were analyzed.Results showed that the microbial diversity and composition of C.palauensis significantly differed between the polyps and skeletons,and between the tropical and subtropical CRR.Regarding bacteria associated with corals,C.palauensis was mainly associated with bacteria closely related to the nitrogen cycle in the subtropical CRR.The relative abundances of Terasakiellaceae and Chlorobium in both coral polyps and skeletons in the subtropical CRR were higher than those in the tropical CRR.In the tropical CRR,C.palauensis was mainly associated with opportunistic pathogenic bacteria.The relative abundances of Tenacibaculum and Vibrio in coral polyps and skeletons in the tropical CRR were higher than those in the subtropical CRR.Regarding archaea associated with corals,polyps and skeletons of C.palauensis in both tropical and subtropical reef areas were dominated by n_Woesearchaeales,and the relative abundance of n_Woesearchaeales in skeletons is significantly higher than that in polyps.In addition,the relative abundances of n_Woesearchaeales in polyps and skeletons in the subtropical CRR were significantly higher than those in the tropical CRR.Regarding fungi associated with corals,Ascomycota was dominant in polyps and skeletons in the subtropical CRR,while Sordariomycetes,Periconia,Cladosporium,and Aspergillus were dominant in polyps and skeletons in the tropical CRR.Besides,the diversity differences of coral-associated microorganisms were related to environmental factors such as nutrients and temperature that may affect the survival of coral-associated microorganisms.These results implied that corals may adjust the composition of microorganisms,conducive the coral holobiont to better adapting the environment.Our research will be beneficial in understanding the differences and adaptations of coral polyp and skeletal microbiome.展开更多
The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The...The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The key to realizing this process lies in the multiple trapping of the in situ generated ketenimine cation by the 3-aminoindazole,which results in the formation of four new chemical bonds and two new rings in one pot.Moreover,the products of this new reaction were found to exhibit aggregationinduced emission(AIE)without modification.展开更多
Ultrathin Li-rich Li-Cu binary alloy has become a competitive anode material for Li metal batteries of high energy density.However,due to the poor-lithiophilicity of the single skeleton structure of Li-Cu alloy,it has...Ultrathin Li-rich Li-Cu binary alloy has become a competitive anode material for Li metal batteries of high energy density.However,due to the poor-lithiophilicity of the single skeleton structure of Li-Cu alloy,it has limitations in inducing Li nucleation and improving electrochemical performance.Hence,we introduced Ag species to Li-Cu alloy to form a 30μm thick Li-rich Li-Cu-Ag ternary alloy(LCA)anode,with Li-Ag infinite solid solution as the active phase,and Cu-based finite solid solutions as three-dimensional(3D)skeleton.Such nano-wire networks with LiCu4 and CuxAgy finite solid solution phases were prepared through a facile melt coating technique,where Ag element can act as lithiophilic specie to enhance the lithiophilicity of built-in skeleton,and regulate the deposition behavior of Li effectively.Notably,the formation of CuxAgy solid solution can strengthen the structural stability of the skeleton,ensuring the geometrical integrity of Li anode,even at the fully delithiated state.Meanwhile,the Li-Ag infinite solid solution phase can promote the Li plating/stripping reversibility of the LCA anode with an improved coulombic efficiency(CE).The synergistic effect between infinite and finite solid solutions could render an enhanced electrochemical performance of Li metal batteries.The LCA|LCA symmetric cells showed a long lifespan of over 600 h with stable polarization voltage of 40 mV,in 1 mA·cm^(-2)/1 mAh·cm^(-2).In addition,the full cells matching our ultrathin LCA anode with 17.2 mg·cm^(-2)mass loading of LiFePO_(4) cathode,can continuously operate beyond 110 cycles at 0.5C,with a high capacity retention of 91.5%.Kindly check and confirm the edit made in the article title.展开更多
In order to realize the resource utilization of construction waste,industrial waste slag and silt,this paper used Portland cement,mineral waste residue and phosphogypsum composite to make cementing material(CMPS)with ...In order to realize the resource utilization of construction waste,industrial waste slag and silt,this paper used Portland cement,mineral waste residue and phosphogypsum composite to make cementing material(CMPS)with construction waste recycled aggregate to solidify silt.The mechanical properties of the solidified silt were analyzed by laboratory solidification test and microscopic examination respectively.In order to clarify the mineral composition,microscopic morphology and pore characteristics of the regenerated aggregate and CMPS solidified silt,X-ray diffractometer(XRD),scanning electron microscope(SEM),and nitrogen adsorption pore analyzer(NA)were used to further explore and analyze the regenerated aggregate and CMPS solidified silt effectively,and further reveal the internal mechanism of the regenerated aggregate and CMPS solidified silt effectively.The experimental results show that the strength of Portland cement-mineral waste residue phosphogypsum terpolymer system curing agent increases by 107.34%than that of single Port-land cement solidified silt at 56 d,and the strength of CMPS solidified silt increases by 25.68%under the action of recycled aggregate framework.The curing age and moisture content of the silt have a high correlation with the strength of the solidified silt.Therefore,the influence law of the above two influencing factors on its mechanical properties is further explored and the strength prediction is made.The microscopic test results show that,based on the hydration of Port-land cement and the pozzolans reaction of mineral waste residue,the solidified system has produced calcium silicate hydrate gel and ettringite crystals with gelatinous properties,which helps to fill the pores and form a denser structure.展开更多
In an era where technological advancement and sustainability converge,developing renewable materials with multifunctional integration is increasingly in demand.This study filled a crucial gap by integrating energy sto...In an era where technological advancement and sustainability converge,developing renewable materials with multifunctional integration is increasingly in demand.This study filled a crucial gap by integrating energy storage,multi-band electromagnetic interference(EMI)shielding,and structural design into bio-based materials.Specifically,conductive polymer layers were formed within the 2,2,6,6-tetramethylpiperidine-1-oxide(TEMPO)-oxidized cellulose fiber skeleton,where a mild TEMPO-mediated oxidation system was applied to endow it with abundant macropores that could be utilized as active sites(specific surface area of 105.6 m2 g-1).Benefiting from the special hierarchical porous structure of the material,the constructed cellulose fiber-derived composites can realize high areal-specific capacitance of 12.44 F cm^(-2)at 5 m A cm^(-2)and areal energy density of 3.99 m Wh cm^(-2)(2005 m W cm^(-2))with an excellent stability of maintaining 90.23%after 10,000 cycles at 50 m A cm^(-2).Meanwhile,the composites showed a high electrical conductivity of 877.19 S m-1 and excellent EMI efficiency(>99.99%)in multiple wavelength bands.The composite material’s EMI values exceed 100 d B across the L,S,C,and X bands,effectively shielding electromagnetic waves in daily life.The proposed strategy paves the way for utilizing bio-based materials in applications like energy storage and EMI shielding,contributing to a more sustainable future.展开更多
Layered ammonium vanadate has become a promising cathode material for aqueous zinc ion batteries(ZIBs)due to its small mass and large ionic radius of ammonium ions as well as the consequent large layer spacing and hig...Layered ammonium vanadate has become a promising cathode material for aqueous zinc ion batteries(ZIBs)due to its small mass and large ionic radius of ammonium ions as well as the consequent large layer spacing and high specific capacity.However,the irreversible de-ammoniation caused by N·H···O bonds damaged would impair cycle life of ZIBs and the strong electrostatic interaction between Zn^(2+)and V-O frame could slower the mobility of Zn^(2+).Furthermore,the thermal instability of ammonium vanadate also limits the use of common carbon coating modification method to solve the problem.Herein,V_(2)CT_(X)MXene was innovatively selected as a bifunctional source to in-situ derivatized(NH_(4))_(2)V_(8)O_(20)·x H_(2)O with amorphous carbon-coated(NHVO@C)via one-step hydrothermal method in relatively moderate temperature.The amorphous carbon shell derived from the V_(2)CT_(X)MXene as a conductive framework to effectively improve the diffusion kinetics of Zn^(2+)and the robust carbon skeleton could alleviate the ammonium dissolution during long-term cycling.As a result,zinc ion batteries using NHVO@C as cathode exhibit superior electrochemical performance.Moreover,the assembled foldable or high loading(10.2 mg/cm^(2))soft-packed ZIBs further demonstrates its practical application.This study provided new insights into the development of the carbon cladding process for thermally unstable materials in moderate temperatures.展开更多
Studying various aurora morphology helps us understand space's physical processes and the mechanisms behind these patterns.Auroral arcs are the brightest and most prominent auroral patterns.Due to the difficulty i...Studying various aurora morphology helps us understand space's physical processes and the mechanisms behind these patterns.Auroral arcs are the brightest and most prominent auroral patterns.Due to the difficulty in precisely defining auroral shape edges,auroral arc skeleton extraction is expected as an alternative representation for studying auroral morphology,resorting skeletons extract key morphological features from complex auroral shapes.Transformer models provide a better understanding of the relationship between the overall morphology and the details when processing image data,so we proposed a Transformer-based method for auroral arc skeleton extraction.Combined with ridge-guided annotation on all-sky images,a Transformer-based skeleton extractor is trained and used to estimate the number of auroral arcs.Experiments demonstrate that the Transformer-based model can more effectively capture structural information and local details of auroral arcs,which is suitable for complex auroral morphologies.展开更多
Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nano...Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nanofiber(PNF)based composite aerogel with excellent EM wave absorption performance was fabricated with cobalt-nickel alloy(CoNi)nanoparticles and carbon nanotubes(CNTs)as magnetic and conductive fillers,respectively.A CNT/PNF composite aerogel was first prepared through a sol-gel and freeze-drying method,and then CoNi nanoparticles were introduced therein through hydrothermal reaction and thermal annealing to obtain the CoNi/CNT/PNF aerogel.CNTs and PNFs were interwoven and constructed a three-dimensional conductive/magnetic cage-like skeleton structure decorating with magnetic CoNi nanoparticles.The cage-like skeleton structure allowed the dissipation of EM waves through multiple mechanisms encompassing conduction loss,magnetic loss,multiple reflection,scattering,and absorption.When its thickness was 4 mm,the CoNi/CNT/PNF aerogel showed a minimal reflection loss of-44.7 dB(at 6.88 GHz),and its broad effective absorption bandwidth covered the entire X-band and Ku-band and most of the C-band(12.32 GHz,from 5.68 GHz to 18 GHz).In addition,the rigid aerogel exhibited an ultralow density(0.107 g/cm^(3)),excellent thermal insulation,and flame retardancy,demonstrating its potential application as a high-performance EM wave absorption material in the fields of aerospace and national defense.展开更多
Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to u...Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to understand the interplays between the mechanical behavior of roots and the root architecture.Full three-dimensional(3D)models of natural tree root systems,Lovell,Marianna,and Myrobalan,that were extracted from the ground by vertical pullout are reconstructed through photogrammetry and later skeletonized as nodes and root branch segments.Combined analyses of the full 3D models and skeletonized models enable a detailed examination of basic bulk properties and quantification of architectural parameters.While the root segments are divided into three categories,trunk root,main lateral root,and remaining roots,the patterns in branching and diameter distributions show significant differences between the trunk and main laterals versus the remaining lateral roots.In general,the branching angle decreases over the sequence of bifurcations.The main lateral roots near the trunk show significant spreading while the lateral roots near the ends grow roughly parallel to the parent root.For branch length,the roots bifurcate more frequently near the trunk and later they grow longer.Local thickness analysis confirms that the root diameter decays at a higher rate near the trunk than in the remaining lateral roots,while the total cross-sectional area across a bifurcation node remains mostly conserved.The histograms of branching angle,and branch length and thickness gradient can be described using lognormal and exponential distributions,respectively.This unique study presents data to characterize mechanically important structural roots,which may help link root architecture to the mechanical behaviors of root structures.展开更多
The next-generation lithium(Li)metal batteries suffer severe low-temperature capacity degradation,appealing for expeditions on solutions.Herein,the feasibility of copper-based skeletons(i.e.,2D Cu foil,3D Cu mesh,and ...The next-generation lithium(Li)metal batteries suffer severe low-temperature capacity degradation,appealing for expeditions on solutions.Herein,the feasibility of copper-based skeletons(i.e.,2D Cu foil,3D Cu mesh,and CuZn mesh)frequently adopted in the stabilization of Li are evaluated at low temperatures.Li growth patterns and stripping behaviors on different skeletons and at different temperatures uncover the dendrite-free and dead-Li-less Li deposition/dissolution on CuZn mesh.Three-electrode impedance indicates the dynamic advantages of CuZn mesh,driving fast Li^(+)crossing through solidelectrolyte-interphase and charge transfer process.Notably,CuZn mesh enables the stable operation and fast charging(1.8 mA cm^(-2))of Li||LiFePO_(4)cells for over 120 cycles at-10℃ with a superior capacity retention of 88%.The success of CuZn mesh can be translated into lower temperature(-20℃)and 1.0-Ah-level pouch cells.This work provides fundamentals on improving low-temperature battery performances by skeletons with regulated spatial structure and lithiophilicity.展开更多
Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystalliz...Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.展开更多
Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, d...Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.展开更多
文摘Background: Off-pump coronary artery bypass grafting (OPCAB) is a surgical procedure that has gained popularity due to its potential benefits over traditional coronary artery bypass grafting, including reduced morbidity and mortality. However, sternal wound complication (SWC) remains challenging following the procedure. The technique of left internal mammary artery (LIMA) harvesting has been shown to impact the incidence of SWC. This study aimed to compare the incidence of SWC between two techniques of LIMA harvesting, i.e., skeletonized and pedicled. Methods: The study was conducted at the Department of Cardiac Surgery, Bangabandhu Sheikh Mujib Medical University, and included 60 patients who underwent OPCAB. The patients were divided into two groups of 30 each based on the technique of LIMA harvesting used, i.e., skeletonized (group A) or pedicled (group B). The postoperative ICU care was given to each patient as per the protocol. The statistical analysis was conducted using the SPSS version 26.0 for Windows software. Results: The results showed that 5 (8.33%) patients developed SWC, with 1 (1.67%) patient in group A and 4 (6.66%) patients in group B. However, the occurrence of SWC was not statistically significant between the two groups (p = 0.35). The mean age, gender distribution, and comorbidities such as hypertension, diabetes, dyslipidemia, and anemia were also not statistically significant between the two groups. The number of smokers was statistically significant between the two groups (p = 0.03), and the occurrence of SWC was found to be higher in smoker patients in group B (p = 0.04). Preoperative and postoperative parameters such as duration of operation, duration of mechanical ventilation, duration of chest drains, duration of the central venous line, and amount of postoperative mediastinal bleeding were also not statistically significant between the two groups. The distribution of wound complications, duration of ICU stays, and hospital stay between the two groups was also not statistically significant. Conclusion: In conclusion, this study found that the incidence of SWC was less in skeletonized LIMA harvesting than in pedicled LIMA harvesting after OPCAB. However, this finding was not statistically significant. Further studies with larger sample sizes may be needed to confirm these results and determine the appropriate technique of LIMA harvesting to decrease the incidence of SWC after OPCAB.
文摘The free flow of skeletonized ITA grafts was compared with that of pedicled ITA grafts. One hundred patients with coronary artery diseases underwent elective CABG. In the group Ⅰ(n= 50), the left ITA was dissected using the skeletonization technique. In the group Ⅱ(n=50), the ITA was harvested as a pedicled graft. Free flow of the ITA was recorded before and 15 min after in- traluminal application of diluted papaverine. Mean arterial pressure was maintained at 9. 31 kPa (70 mmHg). The results showed that before the application of papaverine, free flow of skeletonized and pedicled ITA grafts was identical between the two groups. After treatment with papaverine, the maximum free flow was significantly higher in the skeletonized ITA's in the group Ⅰ(199. 3±69. 6 ml/min) than in the group Ⅱ(145. 7±70. 3 ml/min, P<0. 05). There was on significant differ- ence between the free flow after dilatation of the left and right ITA in the group Ⅰ (left 199. 3±69. 6 ml/mm, right 198. 9±61. 8 ml/mm, respectively). It was concluded that preparation of the ITA with the skeletonization technique resulted in significantly higher free flow capacity than in pedicled grafts and would improve the results of arterial revascularization. The complication rate seems to be lower than with the conventional method.
基金funded by the ICT Division of theMinistry of Posts,Telecommunications,and Information Technology of Bangladesh under Grant Number 56.00.0000.052.33.005.21-7(Tracking No.22FS15306)support from the University of Rajshahi.
文摘The Internet of Things(IoT)and mobile technology have significantly transformed healthcare by enabling real-time monitoring and diagnosis of patients.Recognizing Medical-Related Human Activities(MRHA)is pivotal for healthcare systems,particularly for identifying actions critical to patient well-being.However,challenges such as high computational demands,low accuracy,and limited adaptability persist in Human Motion Recognition(HMR).While some studies have integrated HMR with IoT for real-time healthcare applications,limited research has focused on recognizing MRHA as essential for effective patient monitoring.This study proposes a novel HMR method tailored for MRHA detection,leveraging multi-stage deep learning techniques integrated with IoT.The approach employs EfficientNet to extract optimized spatial features from skeleton frame sequences using seven Mobile Inverted Bottleneck Convolutions(MBConv)blocks,followed by Convolutional Long Short Term Memory(ConvLSTM)to capture spatio-temporal patterns.A classification module with global average pooling,a fully connected layer,and a dropout layer generates the final predictions.The model is evaluated on the NTU RGB+D 120 and HMDB51 datasets,focusing on MRHA such as sneezing,falling,walking,sitting,etc.It achieves 94.85%accuracy for cross-subject evaluations and 96.45%for cross-view evaluations on NTU RGB+D 120,along with 89.22%accuracy on HMDB51.Additionally,the system integrates IoT capabilities using a Raspberry Pi and GSM module,delivering real-time alerts via Twilios SMS service to caregivers and patients.This scalable and efficient solution bridges the gap between HMR and IoT,advancing patient monitoring,improving healthcare outcomes,and reducing costs.
基金supported by the National Natural Science Foundation of China(62272049,62236006,62172045)the Key Projects of Beijing Union University(ZKZD202301).
文摘In recent years,gait-based emotion recognition has been widely applied in the field of computer vision.However,existing gait emotion recognition methods typically rely on complete human skeleton data,and their accuracy significantly declines when the data is occluded.To enhance the accuracy of gait emotion recognition under occlusion,this paper proposes a Multi-scale Suppression Graph ConvolutionalNetwork(MS-GCN).TheMS-GCN consists of three main components:Joint Interpolation Module(JI Moudle),Multi-scale Temporal Convolution Network(MS-TCN),and Suppression Graph Convolutional Network(SGCN).The JI Module completes the spatially occluded skeletal joints using the(K-Nearest Neighbors)KNN interpolation method.The MS-TCN employs convolutional kernels of various sizes to comprehensively capture the emotional information embedded in the gait,compensating for the temporal occlusion of gait information.The SGCN extracts more non-prominent human gait features by suppressing the extraction of key body part features,thereby reducing the negative impact of occlusion on emotion recognition results.The proposed method is evaluated on two comprehensive datasets:Emotion-Gait,containing 4227 real gaits from sources like BML,ICT-Pollick,and ELMD,and 1000 synthetic gaits generated using STEP-Gen technology,and ELMB,consisting of 3924 gaits,with 1835 labeled with emotions such as“Happy,”“Sad,”“Angry,”and“Neutral.”On the standard datasets Emotion-Gait and ELMB,the proposed method achieved accuracies of 0.900 and 0.896,respectively,attaining performance comparable to other state-ofthe-artmethods.Furthermore,on occlusion datasets,the proposedmethod significantly mitigates the performance degradation caused by occlusion compared to other methods,the accuracy is significantly higher than that of other methods.
基金supported in part by the National Natural Science Foundation of China under Grants 61973065,U20A20197,61973063.
文摘Previous multi-view 3D human pose estimation methods neither correlate different human joints in each view nor model learnable correlations between the same joints in different views explicitly,meaning that skeleton structure information is not utilized and multi-view pose information is not completely fused.Moreover,existing graph convolutional operations do not consider the specificity of different joints and different views of pose information when processing skeleton graphs,making the correlation weights between nodes in the graph and their neighborhood nodes shared.Existing Graph Convolutional Networks(GCNs)cannot extract global and deeplevel skeleton structure information and view correlations efficiently.To solve these problems,pre-estimated multiview 2D poses are designed as a multi-view skeleton graph to fuse skeleton priors and view correlations explicitly to process occlusion problem,with the skeleton-edge and symmetry-edge representing the structure correlations between adjacent joints in each viewof skeleton graph and the view-edge representing the view correlations between the same joints in different views.To make graph convolution operation mine elaborate and sufficient skeleton structure information and view correlations,different correlation weights are assigned to different categories of neighborhood nodes and further assigned to each node in the graph.Based on the graph convolution operation proposed above,a Residual Graph Convolution(RGC)module is designed as the basic module to be combined with the simplified Hourglass architecture to construct the Hourglass-GCN as our 3D pose estimation network.Hourglass-GCNwith a symmetrical and concise architecture processes three scales ofmulti-viewskeleton graphs to extract local-to-global scale and shallow-to-deep level skeleton features efficiently.Experimental results on common large 3D pose dataset Human3.6M and MPI-INF-3DHP show that Hourglass-GCN outperforms some excellent methods in 3D pose estimation accuracy.
基金supported by the National Key Research and Development Program of China(2023YFD1700500,2021YFD1700100)the National Natural Science Foundation of China(22177051,32061143045)+2 种基金the Fundamental Research Funds for the Central Universities(KYCYXT2022010)Sichuan Key Research and Development Program(22ZDYF0186,2021YFN0134)the College Student Research Training Program(202110307002T).
文摘As a natural alkaloid found extensively in cereal crops, gramine not only plays a crucial role in protecting barley and other grasses from various pests, but also reduces palatability for ruminants. Scientists are trying to figure out how gramine gets into cereal plants: is it inherently present or transformed through a special process? The latest study published in Science by Sara Leite Dias and co-authors, provides a detailed explanation. The starting point of the transformation is identified, and the transformation process is confirmed through rigorous experiments.
基金supported from the National Natural Science Foundation of China(No.21920102003)the Key-Area Research and Development Program of Guangdong Province(No.2020B0303070002)the National Key R&D Program“Strategic Scientific and Technological Innovation Cooperation”Key Project(No.2022YFE0203600).
文摘Two novel skeleton sesquiterpenoids(1 and 6),along with four new iphionane-type sesquiterpenes(2−5)and six new cyperane-type sesquiterpenes(7−11),were isolated from the whole plant of Artemisia hedinii(A.hedinii).The two novel skeleton compounds(1 and 6)were derived from the decarbonization of iphionane and cyperane-type sesquiterpenes,respectively.Their structures were elucidated through a comprehensive analysis of spectroscopic data,including high-resolution electrospray ionization mass spectrometry(HR-ESI-MS)and 1D and 2D nuclear magnetic resonance(NMR)spectra.The absolute configurations were determined using electronic circular dichroism(ECD)spectra,single-crystal X-ray crystallographic analyses,time-dependent density functional theory(TDDFT)ECD calculation,density functional theory(DFT)NMR calculations,and biomimetic syntheses.The biomimetic syntheses of the two novel skeletons(1 and 6)were inspired by potential biogenetic pathways,utilizing a predominant eudesmane-type sesquiterpene(A)in A.hedinii as the substrate.All compounds were evaluated in LX-2 cells for their anti-hepatic fibrosis activity.Compounds 2,8,and 10 exhibited significant activity in downregulating the expression ofα-smooth muscle actin(α-SMA),a protein involved in hepatic fibrosis.
基金the National Natural Science Foundation of China(No.22471224)。
文摘A category of highly fused diterpenoid natural products possessing a characteristic perhydropyrene-like or rearranged tetracyclic skeleton structure are distributed in different life forms.Compared to traditional polycyclic diterpenoids,their biosynthetic pathways are quite unique and diverse.Chemists have pinpointed a range of this type of unusual diterpenoids:cycloamphilectanes and isocycloamphilectanes,kempenes and rippertanes,hydropyrene and hydropyrenol,along with recently disclosed cephalotanes.This review describes developments in this field and discusses the challenges associated with synthesizing this class of highly complex compounds.
基金The National Natural Science Foundation of China under contract Nos 42206157,42030502,and 42090041the Natural Science Foundation of Guangxi Province under contract No.2022GXNSFBA035449the Self-Topic Project of Guangxi Laboratory on the Study of Coral Reefs in the South China Sea under contract No.GXLSCRSCS2022103.
文摘The environments of tropical and subtropical coral reef regions(CRR)differ from each other;however,it is not known if these environmental differences influence coral polyp and skeleton microbiome composition.In this study,Coelastrea palauensis corals were collected from tropical and subtropical CRR in the South China Sea,and bacterial,archaeal,and fungal communities in polyps and skeletons were analyzed.Results showed that the microbial diversity and composition of C.palauensis significantly differed between the polyps and skeletons,and between the tropical and subtropical CRR.Regarding bacteria associated with corals,C.palauensis was mainly associated with bacteria closely related to the nitrogen cycle in the subtropical CRR.The relative abundances of Terasakiellaceae and Chlorobium in both coral polyps and skeletons in the subtropical CRR were higher than those in the tropical CRR.In the tropical CRR,C.palauensis was mainly associated with opportunistic pathogenic bacteria.The relative abundances of Tenacibaculum and Vibrio in coral polyps and skeletons in the tropical CRR were higher than those in the subtropical CRR.Regarding archaea associated with corals,polyps and skeletons of C.palauensis in both tropical and subtropical reef areas were dominated by n_Woesearchaeales,and the relative abundance of n_Woesearchaeales in skeletons is significantly higher than that in polyps.In addition,the relative abundances of n_Woesearchaeales in polyps and skeletons in the subtropical CRR were significantly higher than those in the tropical CRR.Regarding fungi associated with corals,Ascomycota was dominant in polyps and skeletons in the subtropical CRR,while Sordariomycetes,Periconia,Cladosporium,and Aspergillus were dominant in polyps and skeletons in the tropical CRR.Besides,the diversity differences of coral-associated microorganisms were related to environmental factors such as nutrients and temperature that may affect the survival of coral-associated microorganisms.These results implied that corals may adjust the composition of microorganisms,conducive the coral holobiont to better adapting the environment.Our research will be beneficial in understanding the differences and adaptations of coral polyp and skeletal microbiome.
基金supported by the National Natural Science Foundation of China(Nos.21971080,22171098)supported by Chengdu Guibao Science&Technology Co.,Ltd.This work was also supported by the 111 Project(No.B17019)。
文摘The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The key to realizing this process lies in the multiple trapping of the in situ generated ketenimine cation by the 3-aminoindazole,which results in the formation of four new chemical bonds and two new rings in one pot.Moreover,the products of this new reaction were found to exhibit aggregationinduced emission(AIE)without modification.
基金supported by the National Natural Science Foundation of China(Nos.22379019,52172184)Sichuan Science and Technology Program(No.2024YFHZ0313)S&T Special Program of Huzhou(No.2023GZ03)。
文摘Ultrathin Li-rich Li-Cu binary alloy has become a competitive anode material for Li metal batteries of high energy density.However,due to the poor-lithiophilicity of the single skeleton structure of Li-Cu alloy,it has limitations in inducing Li nucleation and improving electrochemical performance.Hence,we introduced Ag species to Li-Cu alloy to form a 30μm thick Li-rich Li-Cu-Ag ternary alloy(LCA)anode,with Li-Ag infinite solid solution as the active phase,and Cu-based finite solid solutions as three-dimensional(3D)skeleton.Such nano-wire networks with LiCu4 and CuxAgy finite solid solution phases were prepared through a facile melt coating technique,where Ag element can act as lithiophilic specie to enhance the lithiophilicity of built-in skeleton,and regulate the deposition behavior of Li effectively.Notably,the formation of CuxAgy solid solution can strengthen the structural stability of the skeleton,ensuring the geometrical integrity of Li anode,even at the fully delithiated state.Meanwhile,the Li-Ag infinite solid solution phase can promote the Li plating/stripping reversibility of the LCA anode with an improved coulombic efficiency(CE).The synergistic effect between infinite and finite solid solutions could render an enhanced electrochemical performance of Li metal batteries.The LCA|LCA symmetric cells showed a long lifespan of over 600 h with stable polarization voltage of 40 mV,in 1 mA·cm^(-2)/1 mAh·cm^(-2).In addition,the full cells matching our ultrathin LCA anode with 17.2 mg·cm^(-2)mass loading of LiFePO_(4) cathode,can continuously operate beyond 110 cycles at 0.5C,with a high capacity retention of 91.5%.Kindly check and confirm the edit made in the article title.
基金Funded by the Jiangsu Province Industry University Research Project(No.BY20231142)the Yangzhou Science&Technology Program(No.YZ2023061)the Zhenjiang Science&Technology Program(No.SH2022018)。
文摘In order to realize the resource utilization of construction waste,industrial waste slag and silt,this paper used Portland cement,mineral waste residue and phosphogypsum composite to make cementing material(CMPS)with construction waste recycled aggregate to solidify silt.The mechanical properties of the solidified silt were analyzed by laboratory solidification test and microscopic examination respectively.In order to clarify the mineral composition,microscopic morphology and pore characteristics of the regenerated aggregate and CMPS solidified silt,X-ray diffractometer(XRD),scanning electron microscope(SEM),and nitrogen adsorption pore analyzer(NA)were used to further explore and analyze the regenerated aggregate and CMPS solidified silt effectively,and further reveal the internal mechanism of the regenerated aggregate and CMPS solidified silt effectively.The experimental results show that the strength of Portland cement-mineral waste residue phosphogypsum terpolymer system curing agent increases by 107.34%than that of single Port-land cement solidified silt at 56 d,and the strength of CMPS solidified silt increases by 25.68%under the action of recycled aggregate framework.The curing age and moisture content of the silt have a high correlation with the strength of the solidified silt.Therefore,the influence law of the above two influencing factors on its mechanical properties is further explored and the strength prediction is made.The microscopic test results show that,based on the hydration of Port-land cement and the pozzolans reaction of mineral waste residue,the solidified system has produced calcium silicate hydrate gel and ettringite crystals with gelatinous properties,which helps to fill the pores and form a denser structure.
基金the financial support of a special fund from the Beijing Key Laboratory of Lignocellulosic Chemistry,College of Materials Science and Technology,Beijing Forestry UniversityFinancial support from NSERC Discovery grant(RGPIN-2017-06737)+1 种基金Canada Research Chair program is also acknowledgedthe China Scholarship Council(CSC)for its financial support(CSC No.202306510047)。
文摘In an era where technological advancement and sustainability converge,developing renewable materials with multifunctional integration is increasingly in demand.This study filled a crucial gap by integrating energy storage,multi-band electromagnetic interference(EMI)shielding,and structural design into bio-based materials.Specifically,conductive polymer layers were formed within the 2,2,6,6-tetramethylpiperidine-1-oxide(TEMPO)-oxidized cellulose fiber skeleton,where a mild TEMPO-mediated oxidation system was applied to endow it with abundant macropores that could be utilized as active sites(specific surface area of 105.6 m2 g-1).Benefiting from the special hierarchical porous structure of the material,the constructed cellulose fiber-derived composites can realize high areal-specific capacitance of 12.44 F cm^(-2)at 5 m A cm^(-2)and areal energy density of 3.99 m Wh cm^(-2)(2005 m W cm^(-2))with an excellent stability of maintaining 90.23%after 10,000 cycles at 50 m A cm^(-2).Meanwhile,the composites showed a high electrical conductivity of 877.19 S m-1 and excellent EMI efficiency(>99.99%)in multiple wavelength bands.The composite material’s EMI values exceed 100 d B across the L,S,C,and X bands,effectively shielding electromagnetic waves in daily life.The proposed strategy paves the way for utilizing bio-based materials in applications like energy storage and EMI shielding,contributing to a more sustainable future.
基金financially supported by the National Natural Science Foundation of China(Nos.52402271,22005167 and52302273)the Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province(No.2024KJH129)+2 种基金the Taishan Scholar Project of Shandong Provinceof China(Nos.tsqn202211160,tsqn202312199)Shandong Provincial Natural Science Foundation of China(Nos.ZR2022QE003 and ZR2023QE176)China Postdoctoral Science Foundation(No.2023M741810)。
文摘Layered ammonium vanadate has become a promising cathode material for aqueous zinc ion batteries(ZIBs)due to its small mass and large ionic radius of ammonium ions as well as the consequent large layer spacing and high specific capacity.However,the irreversible de-ammoniation caused by N·H···O bonds damaged would impair cycle life of ZIBs and the strong electrostatic interaction between Zn^(2+)and V-O frame could slower the mobility of Zn^(2+).Furthermore,the thermal instability of ammonium vanadate also limits the use of common carbon coating modification method to solve the problem.Herein,V_(2)CT_(X)MXene was innovatively selected as a bifunctional source to in-situ derivatized(NH_(4))_(2)V_(8)O_(20)·x H_(2)O with amorphous carbon-coated(NHVO@C)via one-step hydrothermal method in relatively moderate temperature.The amorphous carbon shell derived from the V_(2)CT_(X)MXene as a conductive framework to effectively improve the diffusion kinetics of Zn^(2+)and the robust carbon skeleton could alleviate the ammonium dissolution during long-term cycling.As a result,zinc ion batteries using NHVO@C as cathode exhibit superior electrochemical performance.Moreover,the assembled foldable or high loading(10.2 mg/cm^(2))soft-packed ZIBs further demonstrates its practical application.This study provided new insights into the development of the carbon cladding process for thermally unstable materials in moderate temperatures.
基金supported by the National Natural Science Foundation of China(Grant no.41874173)。
文摘Studying various aurora morphology helps us understand space's physical processes and the mechanisms behind these patterns.Auroral arcs are the brightest and most prominent auroral patterns.Due to the difficulty in precisely defining auroral shape edges,auroral arc skeleton extraction is expected as an alternative representation for studying auroral morphology,resorting skeletons extract key morphological features from complex auroral shapes.Transformer models provide a better understanding of the relationship between the overall morphology and the details when processing image data,so we proposed a Transformer-based method for auroral arc skeleton extraction.Combined with ridge-guided annotation on all-sky images,a Transformer-based skeleton extractor is trained and used to estimate the number of auroral arcs.Experiments demonstrate that the Transformer-based model can more effectively capture structural information and local details of auroral arcs,which is suitable for complex auroral morphologies.
基金the National Natural Science Foundation of China(52203100)Shaanxi Province Key Research and Development Plan Project(2024GX-YBXM-386)+3 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Foundation of Chongqing,China(2023NSCQ-MSX2682)Undergraduate Innovation&Business Program of Northwestern Polytechnical University(S202310699322)the Analytical&Testing Center of Northwestern Polytechnical University for SEM tests performed in this work.
文摘Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nanofiber(PNF)based composite aerogel with excellent EM wave absorption performance was fabricated with cobalt-nickel alloy(CoNi)nanoparticles and carbon nanotubes(CNTs)as magnetic and conductive fillers,respectively.A CNT/PNF composite aerogel was first prepared through a sol-gel and freeze-drying method,and then CoNi nanoparticles were introduced therein through hydrothermal reaction and thermal annealing to obtain the CoNi/CNT/PNF aerogel.CNTs and PNFs were interwoven and constructed a three-dimensional conductive/magnetic cage-like skeleton structure decorating with magnetic CoNi nanoparticles.The cage-like skeleton structure allowed the dissipation of EM waves through multiple mechanisms encompassing conduction loss,magnetic loss,multiple reflection,scattering,and absorption.When its thickness was 4 mm,the CoNi/CNT/PNF aerogel showed a minimal reflection loss of-44.7 dB(at 6.88 GHz),and its broad effective absorption bandwidth covered the entire X-band and Ku-band and most of the C-band(12.32 GHz,from 5.68 GHz to 18 GHz).In addition,the rigid aerogel exhibited an ultralow density(0.107 g/cm^(3)),excellent thermal insulation,and flame retardancy,demonstrating its potential application as a high-performance EM wave absorption material in the fields of aerospace and national defense.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2024-00340851)the Engineering Research Center Program of the National Science Foundation(NSF)under NSF Cooperative Agreement EEC-1449501.
文摘Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to understand the interplays between the mechanical behavior of roots and the root architecture.Full three-dimensional(3D)models of natural tree root systems,Lovell,Marianna,and Myrobalan,that were extracted from the ground by vertical pullout are reconstructed through photogrammetry and later skeletonized as nodes and root branch segments.Combined analyses of the full 3D models and skeletonized models enable a detailed examination of basic bulk properties and quantification of architectural parameters.While the root segments are divided into three categories,trunk root,main lateral root,and remaining roots,the patterns in branching and diameter distributions show significant differences between the trunk and main laterals versus the remaining lateral roots.In general,the branching angle decreases over the sequence of bifurcations.The main lateral roots near the trunk show significant spreading while the lateral roots near the ends grow roughly parallel to the parent root.For branch length,the roots bifurcate more frequently near the trunk and later they grow longer.Local thickness analysis confirms that the root diameter decays at a higher rate near the trunk than in the remaining lateral roots,while the total cross-sectional area across a bifurcation node remains mostly conserved.The histograms of branching angle,and branch length and thickness gradient can be described using lognormal and exponential distributions,respectively.This unique study presents data to characterize mechanically important structural roots,which may help link root architecture to the mechanical behaviors of root structures.
基金the funding support of the National Natural Science Foundation of China(52103342,22209032 and 22479134)Natural Science Foundation of Zhejiang Province(LY24B030008)+1 种基金China Jiliang University Research Fund Program for Young Scholars(221040)the funding support of the Zhejiang Provincial College Students’Scientific Research and Innovation Activity(Xinmiao Talent)Program(2023R409A045)。
文摘The next-generation lithium(Li)metal batteries suffer severe low-temperature capacity degradation,appealing for expeditions on solutions.Herein,the feasibility of copper-based skeletons(i.e.,2D Cu foil,3D Cu mesh,and CuZn mesh)frequently adopted in the stabilization of Li are evaluated at low temperatures.Li growth patterns and stripping behaviors on different skeletons and at different temperatures uncover the dendrite-free and dead-Li-less Li deposition/dissolution on CuZn mesh.Three-electrode impedance indicates the dynamic advantages of CuZn mesh,driving fast Li^(+)crossing through solidelectrolyte-interphase and charge transfer process.Notably,CuZn mesh enables the stable operation and fast charging(1.8 mA cm^(-2))of Li||LiFePO_(4)cells for over 120 cycles at-10℃ with a superior capacity retention of 88%.The success of CuZn mesh can be translated into lower temperature(-20℃)and 1.0-Ah-level pouch cells.This work provides fundamentals on improving low-temperature battery performances by skeletons with regulated spatial structure and lithiophilicity.
基金Project supported by Anhui Natural Science(1808085ME136)。
文摘Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.
文摘Visible light photocatalytic redox catalysis has become a powerful tool for organic synthesis, and has opened up new avenues for the formation of challenging structural skeletons and chemical bonds. In this respect, diverse photocatalysts, including ruthenium(II), iridium(Ⅲ), and organic dyes, have been most commonly applied.
