Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometri...Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms,thus exhibiting superior electrocata-lytic activity and durability.However,quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging.Herein,a series of ternary Pt_(2)NiCo interme-tallic catalysts(o-Pt_(2)NiCo)with different ordering degree were synthesized by annealing temperature modulation.Among them,the o-Pt_(2)NiCo which annealed at 800℃for two hours exhibits the highest ordering degree and the optimal ORR ac-tivity,which the mass activity of o-Pt_(2)NiCo is 1.8 times and 2.8 times higher than that of disordered Pt_(2)NiCo alloy and Pt/C.Furthermore,the o-Pt_(2)NiCo still maintains 70.8%mass activity after 30,000 potential cycles.Additionally,the ORR activity test results for Pt_(2)NiCo IMC with different ordering degree also provide a positive correlation between the ordering degree and ORR activity.This work provides a prospective design direction for ternary Pt-based electrocatalysts.展开更多
Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects o...Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.展开更多
In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we pr...In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.展开更多
As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from di...As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from different studies,this study constructs a refined block model(including Qilian,Alxa,Ordos,Xining,Haiyuan,and Lanzhou blocks)and uses the grid search and simulated annealing methods to invert GPS data for slip rate and locking degree of the Haiyuan fault zone.The results are as follows:(1)The sinistral slip rates in the western,middle,and eastern segments are 4.93-5.22 mm/a,1.52-4.94 mm/a,and 0.43-1.18 mm/a,decreasing eastward on the whole,while the compression rates are 0.45-1.26 mm/a,0.58-2.62 mm/a,and3.52-4.48 mm/a,increasing eastward on the whole.(2)The locking depth of the western segment increases from about 5 km to about 20 km eastward;the middle segment decreases and then increases eastward;the eastern segment concentrates at about 20 km(PHI is about 0.86).(3)The slip deficit is relatively higher in the Lenglongling,Jinqianghe,Maomaoshan,and Liupanshan faults(averaging about 3.42 mm/a,4.16 mm/a,4.23 mm/a,and 3.43 mm/a within 20 km).(4)The Qilian,Alxa,Xining,Lanzhou,and Haiyuan blocks rotate clockwise,while the Ordos block rotates counterclockwise.Additionally,by comparing different block models,the Haiyuan block should be considered independently.The Haiyuan fault zone adjusts surrounding block movements and uplifts Liupanshan mountain tectonically.The results can provide important references for understanding the regional earthquake risk and deformation mechanism.展开更多
The dynamic behavior of high-speed craft navigating through variable sea states plays a pivotal role in ensuring maritime safety.However,many existing simulation approaches rely on linear or overly simplified represen...The dynamic behavior of high-speed craft navigating through variable sea states plays a pivotal role in ensuring maritime safety.However,many existing simulation approaches rely on linear or overly simplified representations of the marine environment,thereby limiting the fidelity of motion predictions.This study explores the motion characteristics of a 4.5-t high-speed vessel by conducting fully coupled numerical simulations using the STAR-CCM+software.The analysis considers both calm and varying sea conditions,incorporating fluctuations in wave height,wavelength,and wind speed to reflect more realistic operating scenarios.Simulation results reveal that the vessel’s hydrodynamic response is highly sensitive to changes in sea state.As conditions deteriorate,the free surface becomes increasingly complex,with higher wave amplitudes and more pronounced interactions between the waves generated by the vessel and those imposed by the external environment.These effects lead to significant increases in roll,pitch,heave,and sway motions,thereby imposing greater demands on the vessel’s dynamic stability and operational safety.Furthermore,both hydrodynamic resistance and propulsive thrust exhibit notable dependence on sea state and vessel speed.Total resistance generally increases with rougher sea conditions,while thrust tends to rise with increasing forward speed.Under calm or mildly disturbed waters,a Froude number(Fr)of 0.5 appears to offer an optimal balance for initiating and controlling primary motions such as roll,pitch,heave,and sway.Conversely,in more challenging conditions-such as those represented by a Sea State 3-effective motion control is better achieved at a higher Froude number of approximately 1.0.展开更多
Identifying critical nodes is a pivotal research topic in network science,yet the efficient and accurate detection of highly influential nodes remains a challenge.Existing centrality measures predominantly rely on loc...Identifying critical nodes is a pivotal research topic in network science,yet the efficient and accurate detection of highly influential nodes remains a challenge.Existing centrality measures predominantly rely on local or global topological structures,often overlooking indirect connections and their interaction strengths.This leads to imprecise assessments of node importance,limiting practical applications.To address this,we propose a novel node centrality measure,termed six-degree gravity centrality(SDGC),grounded in the six degrees of separation theory,for the precise identification of influential nodes in networks.Specifically,we introduce a set of node influence parameters—node mass,dynamic interaction distance,and attraction coefficient—to enhance the gravity model.Node mass is calculated by integrating K-shell and closeness centrality measures.The dynamic interaction distance,informed by the six-degrees of separation theory,is determined through path searches within six hops between node pairs.The attraction coefficient is derived from the difference in K-shell values between nodes.By integrating these parameters,we develop an improved gravity model to quantify node influence.Experiments conducted on nine real-world networks demonstrate that SDGC significantly outperforms nine existing classical and state-of-the-art methods in identifying the influential nodes.展开更多
BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To...BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To examine changes in DC values and their use as neuroimaging biomarkers in anxious and non-anxious MDD patients.METHODS We examined 23 anxious MDD patients,30 nonanxious MDD patients,and 28 healthy controls(HCs)using the DC for data analysis.RESULTS Compared with HCs,the anxious MDD group reported markedly reduced DC values in the right fusiform gyrus(FFG)and inferior occipital gyrus,whereas elevated DC values in the left middle frontal gyrus and left inferior parietal angular gyrus.The nonanxious MDD group exhibited surged DC values in the bilateral cerebellum IX,right precuneus,and opercular part of the inferior frontal gyrus.Unlike the nonanxious MDD group,the anxious MDD group exhibited declined DC values in the right FFG and bilateral calcarine(CAL).Besides,declined DC values in the right FFG and bilateral CAL negatively correlated with anxiety scores in the MDD group.CONCLUSION This study shows that abnormal DC patterns in MDD,especially in the left CAL,can distinguish MDD from its anxiety subtype,indicating a potential neuroimaging biomarker.展开更多
Objective:To analyze the treatment effect of standardized bronchoscopic interventional therapy(i.e.,interventional therapy)on airway stenosis.Methods:Forty patients with airway stenosis admitted to the hospital betwee...Objective:To analyze the treatment effect of standardized bronchoscopic interventional therapy(i.e.,interventional therapy)on airway stenosis.Methods:Forty patients with airway stenosis admitted to the hospital between September 2022 and September 2024 were selected and randomly divided into two groups using a random number table.The experimental group received interventional therapy,while the reference group received conventional treatment.The total effective rate,degree of airway stenosis,shortness of breath score,and lung function indicators were compared.Results:The total effective rate in the experimental group was higher than that in the reference group.The proportion of mild stenosis in the degree of airway stenosis was higher in the experimental group than in the reference group.The shortness of breath score was lower in the experimental group than in the reference group.The lung function indicators were better in the experimental group than in the reference group(P<0.05).Conclusion:Interventional therapy is effective for patients with airway stenosis,as it can reduce the degree of stenosis,improve symptoms of shortness of breath,and protect patients’lung function.展开更多
BACKGROUND The degree of obstruction plays an important role in decision-making for obstructive colorectal cancer(OCRC).The existing assessment still relies on the colorectal obstruction scoring system(CROSS)which is ...BACKGROUND The degree of obstruction plays an important role in decision-making for obstructive colorectal cancer(OCRC).The existing assessment still relies on the colorectal obstruction scoring system(CROSS)which is based on a comprehensive analysis of patients’complaints and eating conditions.The data collection relies on subjective descriptions and lacks objective parameters.Therefore,a scoring system for the evaluation of computed tomography-based obstructive degree(CTOD)is urgently required for OCRC.AIM To explore the relationship between CTOD and CROSS and to determine whether CTOD could affect the short-term and long-term prognosis.METHODS Of 173 patients were enrolled.CTOD was obtained using k-means,the ratio of proximal to distal obstruction,and the proportion of nonparenchymal areas at the site of obstruction.CTOD was integrated with the CROSS to analyze the effect of emergency intervention on complications.Short-term and long-term outcomes were compared between the groups.RESULTS CTOD severe obstruction(CTOD grade 3)was an independent risk factor[odds ratio(OR)=3.390,95%confidence interval(CI):1.340-8.570,P=0.010]via multivariate analysis of short-term outcomes,while CROSS grade was not.In the CTOD-CROSS grade system,for the non-severe obstructive(CTOD 1-2 to CROSS 1-4)group,the complication rate of emergency interventions was significantly higher than that of non-emergency interventions(71.4%vs 41.8%,P=0.040).The postoperative pneumonia rate was higher in the emergency intervention group than in the non-severe obstructive group(35.7%vs 8.9%,P=0.020).However,CTOD grade was not an independent risk factor of overall survival and progression-free survival.CONCLUSION CTOD was useful in preoperative decision-making to avoid unnecessary emergency interventions and complications.展开更多
Delay aware routing is now widely used to provide efficient network transmission. However, for newly developing or developed mobile communication networks(MCN), only limited delay data can be obtained. In such a netwo...Delay aware routing is now widely used to provide efficient network transmission. However, for newly developing or developed mobile communication networks(MCN), only limited delay data can be obtained. In such a network, the delay is with epistemic uncertainty, which makes the traditional routing scheme based on deterministic theory or probability theory not applicable. Motivated by this problem, the MCN with epistemic uncertainty is first summarized as a dynamic uncertain network based on uncertainty theory, which is widely applied to model epistemic uncertainties. Then by modeling the uncertain end-toend delay, a new delay bounded routing scheme is proposed to find the path with the maximum belief degree that satisfies the delay threshold for the dynamic uncertain network. Finally, a lowEarth-orbit satellite communication network(LEO-SCN) is used as a case to verify the effectiveness of our routing scheme. It is first modeled as a dynamic uncertain network, and then the delay bounded paths with the maximum belief degree are computed and compared under different delay thresholds.展开更多
The interaction between regular waves and an oscillating wave energy converter(WEC)in front of a vertical seawall is investigated using a 2D analytical model.A three-degree of freedom(DOF)WEC and a WEC hinged to the s...The interaction between regular waves and an oscillating wave energy converter(WEC)in front of a vertical seawall is investigated using a 2D analytical model.A three-degree of freedom(DOF)WEC and a WEC hinged to the seawall(constrained to pitch mode)are considered to examine the influence of the DOF of the WEC on the wave energy extraction performance.Results show that the piston-mode water resonance in the gap and the coupled WEC and water column resonant motion significantly influence the wave energy extraction efficiency.At low frequency,the case with a 3-DOF WEC has a broader high-efficiency bandwidth than that with a heaving WEC.However,3-DOF WEC exhibits worse performance at high frequencies.The frequency response of the wave energy capture width ratio(CWR)for the pitching WEC case shows a trimodal trend under the specified conditions.It showcases the best overall wave energy extraction performance in terms of the high-efficiency bandwidth.Furthermore,a parametric study indicates that the gap distance between the WEC and the seawall has tremendous effects on the CWR of both cases.As the position of the hinge point of the pitching WEC changes,the CWR at the low and high frequencies shows opposite trends.展开更多
The use of hot recycled asphalt mixture(HRAM)allows for a reduction in the depletion of non-renewable resources and presents environmental benefits.However,concerns arise regarding the performance of HRAM due to the l...The use of hot recycled asphalt mixture(HRAM)allows for a reduction in the depletion of non-renewable resources and presents environmental benefits.However,concerns arise regarding the performance of HRAM due to the lower degree of blending(DOB)of virgin and aged asphalt(V&A asphalt).This paper aims to provide an up-to-date review on the DOB of V&A asphalt in HRAM.Initially,the paper introduces the DOB of V&A asphalt,followed by an analysis of the blending theory,evaluation methods,and influencing factors of DOB.Subsequently,the effect of DOB on the performance of HRAM is investigated,and molecular dynamic simulation is utilized to analyze the blend of V&A asphalt.Finally,methods for improving DOB are summarized.It was found that the use of high-resolution microscopy with tracer methods such as SEM/EDS was an effective way to characterize DOB.Furthermore,the chemical composition and colloid structure between virgin and aged asphalt are crucial to DOB.Additionally,improving DOB by utilizing the coupling effect of time and temperature during transportation,paving,and compaction stages is promising.Future research should focus on standardizing test methods,refining field simulation models,and developing intelligent construction technologies to achieve more efficient and durable blending.This review provides theoretical guidance and practical references for improving the DOB of V&A asphalt and promoting sustainable pavement construction.展开更多
Correctly tracking the evolution of spatial heterogeneity of local degree of saturation(Sr)in unsaturated soils is essential to explain the seepage phenomenon,which is crucial to assessing slope stability.Several meth...Correctly tracking the evolution of spatial heterogeneity of local degree of saturation(Sr)in unsaturated soils is essential to explain the seepage phenomenon,which is crucial to assessing slope stability.Several methods exist for quantifying the heterogeneity of local S_(r).However,a comprehensive comparison of these methods in terms of accuracy,relative advantages,and disadvantages is currently lacking.This paper presents a comparative analysis of local Sr obtained at multiple scales,ranging from the element scale to the slice,representative element volume(REV),pore,and voxel scales.The spatial heterogeneity of Sr in an unsaturated glass beads specimen at different matric suctions was visualised and quantified by multiscale X-ray micro-focus computed tomography image-based analysis methods.Local Sr obtained at different scales displayed a comparable trend along the sample depth,yet the REV-scale method showed a much scattered and discontinuous distribution.In contrast,the pore-scale method detected a distinct two-clustered,bimodal distribution of S_(r).The pore-scale method has the highest integrated resolution,as it has the highest spatial resolution(i.e.number of data points)and provides more information(i.e.number of extractable physical parameters).This method thus provides a more effective approach for tracking the spatial heterogeneity of S_(r).Based on this method,pore-scale water retention curves were determined,offering new quantitative means to characterise pore water heterogeneity and explainwater drainage processes such as hysteresis at the pore scale.展开更多
This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(S...This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(SDOF)and the experimentally validated Finite Element(FE)methods(LSDYNA).For this purpose,special atten-tion is given to calculating the response of H-shaped steel columns under blast.The damage amount is determined based on the support rotation criterion,which is expressed as a function of their maximum lateral mid-span dis-placement.To account for uncertainties in input parameters and obtain the failure probability,the Monte Carlo simulation(MCS)method is employed,complemented by the Latin Hypercube Sampling(LHS)method to reduce the number of simulations.A parametric analysis is hence performed to examine the effect of several input pa-rameters(including both deterministic and probabilistic parameters)on the probability of column damage as a function of support rotation.First,the MSDOF method confirms its higher accuracy in estimating the probability of column damage due to blast,compared to the conventional SDOF.The collected results also show that un-certainties of several input parameters have significant effects on the column behavior.In particular,geometric parameters(including cross-sectional characteristics,boundary conditions and column length)have major effect on the corresponding column response,in the same way of input blast load parameters and material properties.展开更多
A floating horizontal-axis tidal current turbine(HATT)is an underwater power generation device where cavitation inevitably occurs on blade surfaces,severely affecting a turbine’s lifespan.Under wave action,these floa...A floating horizontal-axis tidal current turbine(HATT)is an underwater power generation device where cavitation inevitably occurs on blade surfaces,severely affecting a turbine’s lifespan.Under wave action,these floating turbines exhibit six degrees of freedom motion,potentially intensifying the cavitation on the blade surfaces.This study selects three types of oscillatory motions from the six degrees of freedom:roll,yaw,and pitch.Computational fluid dynamics(CFD)methods are used for numerical calculations,and transient simulations of multiphase flow are conducted on the basis of the Reynolds-Averaged Navier-Stokes(RANS)model.Research has revealed strong correlations between flow velocity,the blade tip speed ratio,and cavitation.During oscillatory motion,the motion period and amplitude also significantly impact cavitation.In roll motion,the cavitation rate can increase by up to 59%with decreasing period,whereas in pitch and yaw motions,the increases are 7.57 times and 36%larger,respectively.With an increase in amplitude during roll motion,the cavitation rate can increase by up to 1.08 times,whereas in pitch and yaw motions,the increases are 3.49 times and 45%,respectively.The cavitation rate on the blade surfaces is the highest in pitch motion,followed by roll and yaw motions.展开更多
Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermen...Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.展开更多
In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and ...In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and subsequent annealing.Due to the identical metal core,these nanoparticles exhibite a similar permeability,but significantly varying permittivity depending on how much C shells have been graphi-tized.It was discovered that proper graphitization of Fe-C nanoparticles annealed at 1350 ℃ can pro-duce excellent microwave absorption(MA),decent dielectric loss tangent in high frequency region,and moderately strong dielectric loss and attenuation properties.Furthermore,the threshold value of 1/ω is discovered to be a crucial parameter in the theoretical analysis of nonlinear behavior of polarization loss,and thus MA performance of the nanoparticles.This research offers a useful method for creating metal-C nanoparticles with various levels of C shell graphitization.It also provides a clear answer to the crucial question of how the level of C shell graphitization affects the MA performance of metal-C nanoparticles.These results may serve as a reference for the development and mechanism analysis of highly effective metal-C based absorbers.展开更多
Polarization upconversion luminescence(PUCL)of lanthanide ions(Ln^(3+))has been widely used in single particle tracking,microfluidics detection,three-dimensional displays,and so on.However,no effective strategy has be...Polarization upconversion luminescence(PUCL)of lanthanide ions(Ln^(3+))has been widely used in single particle tracking,microfluidics detection,three-dimensional displays,and so on.However,no effective strategy has been developed for modulating PUCL.Here we report a strategy to regulate PUCL in Ho^(3+)-doped NaYF4single nanorods based on the number of upconversion photons.By constructing a multiphoton upconversion system for Ho^(3+),we regulate the degree of polarization(DOP)of PUCL from 0.590 for two-photon luminescence to 0.929 for three-photon upconversion luminescence(UCL).Furthermore,our strategy is verified from cross-relaxation between Ho^(3+)and Yb^(3+),excitation wavelength,excitation power density,and local site symmetry.And this regulation strategy of PUCL has also been achieved in Tm^(3+),with the DOP ranging from 0.233 for two-photon luminescence to 0.925 for four-photon UCL Besides,multi-dimensional anti-counterfeiting display has been explored with PUCL.This work provides an effective strategy for regulating PUCL and also provides more opportunities for the development of polarization display optical encoding,anti-counterfeiting,and integrated optical devices.展开更多
Let G be a graph on n vertices whose degree sequence is d_(1)≥…≥d_(n).For a positive integer p,the degree power of G is defined by e_p(G)=∑_(i=1)^(n) d_(i)^(p).In this paper,by majorization,we prove that for a min...Let G be a graph on n vertices whose degree sequence is d_(1)≥…≥d_(n).For a positive integer p,the degree power of G is defined by e_p(G)=∑_(i=1)^(n) d_(i)^(p).In this paper,by majorization,we prove that for a minimally k-connected graph G of order n≥4k,it always holds e_(2)(G)≤kn(n-k)and the extremal graph is K_(k,n-k).Furthermore,we respectively determine the maximum degree powers among all minimally 2(3)-connected graphs and minimally 2-edgeconnected graphs,whose extremal graphs are also characterized.展开更多
Flexural toppling occurs when a series of layered rock masses bend towards their free face.It is important to evaluate the maximum bending degree and the requirement of supports of flexural toppling rock mass to preve...Flexural toppling occurs when a series of layered rock masses bend towards their free face.It is important to evaluate the maximum bending degree and the requirement of supports of flexural toppling rock mass to prevent rock mass cracking and even failure leading to a landslide.Based on the rock tensile strain-softening model,this study proposes a method for calculating the maximum curvature(C_(ppmax))of flexural toppling rock masses.By applying this method to calculate Cppmax of 9 types of rock masses with different hardness and rock layer thickness,some conclusions are drawn:(1)the internal key factors affecting C_(ppmax)are E^(⋆)(E^(⋆)=E_(ss)/E_(0),where E_(0)and E_(ss)are the mean deformation moduli of the rock before and after reaching its peak tensile strength,respectively),the strainεt corresponding to the tensile strength of rock,and the thickness(h)of rock layers;(2)hard rock layers are more likely to develop into block toppling than soft rock layers;and(3)thin rock layers are more likely to remain in flexural toppling state than thick rock layers.In addition,it is found that C_(ppmax)for flexural toppling rock masses composed of bedded rocks such as gneiss is related to the tensile direction.展开更多
基金supported by the National Natural Science Foundation(22279036)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003).
文摘Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction(ORR).Atomic ordered intermetallic compounds(IMC)provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms,thus exhibiting superior electrocata-lytic activity and durability.However,quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging.Herein,a series of ternary Pt_(2)NiCo interme-tallic catalysts(o-Pt_(2)NiCo)with different ordering degree were synthesized by annealing temperature modulation.Among them,the o-Pt_(2)NiCo which annealed at 800℃for two hours exhibits the highest ordering degree and the optimal ORR ac-tivity,which the mass activity of o-Pt_(2)NiCo is 1.8 times and 2.8 times higher than that of disordered Pt_(2)NiCo alloy and Pt/C.Furthermore,the o-Pt_(2)NiCo still maintains 70.8%mass activity after 30,000 potential cycles.Additionally,the ORR activity test results for Pt_(2)NiCo IMC with different ordering degree also provide a positive correlation between the ordering degree and ORR activity.This work provides a prospective design direction for ternary Pt-based electrocatalysts.
文摘Objective: To evaluate the improvement effect of combined treatment of eschar abrasion, nanosilver dressing, and mussel mucin spray on wound healing in patients with second-degree burns, and to explore their effects on the expression level of (advanced glycation end products) AGEs in wound tissue, so as to provide a basis for the application of AGEs expression level in wound tissue in the future clinical treatment of second-degree burns. Methods: Patients with second-degree burns admitted to the Department of Burns and Plastic Surgery of the Second Affiliated Hospital of Shantou University Medical College from July 2023 to July 2024 were selected as the research subjects. This study was a non-double-blind study, and both patients and researchers were aware of the treatment methods. They were randomly divided into Group A (control group) and Group B (study group). According to the order of their visits, the patients were numbered in advance;then the seed number was taken, and 70 random numbers were generated on the computer using SAS, the first 35 corresponding to group A, and the last 35 corresponding to group B;the random numbers were arranged from small to large, and the rank of the random numbers was the patient number;finally, the patient numbers were arranged from small to large, and the corresponding groups were the grouping scheme. 1) Wound healing time: The wound healing was observed every day, and the wound healing time was calculated when the wound was completely epithelialized. 2) Wound healing: The wound healing area was measured 1, 7, and 14 days after treatment, and transparent paper was used to record combined with a computer-assisted imaging system. Wound healing rate = wound healing area (cm2)/total wound area before treatment (cm2) × 100%. The time for complete wound healing was recorded in the two groups of patients. 3) Pain: The pain was evaluated at 1, 7, and 14 days after treatment using the visual analogue scale (VAS). The higher the score, the more severe the pain. 4) Scar condition: Scar formation was evaluated 1, 3, and 6 months after wound healing using the VAS scale, with a total score of 15 points. The higher the score, the more severe the scar. 5) Detect the expression of AGEs in wound tissue. Results: The wound healed 14.03 ± 2.28 days after eschar removal, with a cure rate of 97.8%. No infection occurred in the wound after eschar removal in all patients. The wound healing time ranged from 9 to 23 days, with an average healing time of 28.41 ± 1.45 days. The healing quality was satisfactory. The Vancouver Scar Scale scored the wound healing scar as 0.81 ± 0.73 points. Western blot was used to detect the expression of AGEs, (receptor for advanced glycation end products) RAGE, and protein in the wound tissue. Results After 7, 14, and 28 days of medication, the wounds of diabetic patients healed well. The drug treatment efficacy and hydroxyproline content showed an upward trend, and the expression levels of AGEs, RAGE, and HIF-1a proteins showed a downward trend. Compared with day 0, the hydroxyproline content of the wound granulation tissue on days 7, 14, and 28 was significantly increased (P< 0.01), and the expression levels of AGEs, RAGE, and HIF-1α proteins were significantly downregulated (P< 0.05 or P< 0.01). Conclusion: Monitoring the expression levels of AGEs and RAGE can reflect the wound-healing effect of patients with second-degree burns, and the prognosis of the wound is closely related to the expression levels of AGEs, RAGE, and scab abrasion. In the treatment of second-degree burn wounds, scab abrasion can grasp the level of necrotic scab removal, can achieve “relatively accurate” removal of necrotic tissue, maximally protect the ecological tissue between wounds and retaining normal tissue, and can play a positive role in promoting the healing process of burn wounds;at the same time, nanosilver dressings have good antibacterial properties and high safety, and mussel mucin has anti-inflammatory and antioxidant activities and the characteristics of blocking nerve endings, which can effectively relieve the burning, stinging, and itching of sensitive skin and effectively promote wound healing.
基金supported in part by the Education Reform Key Projects of Heilongjiang Province under Grant Nos.SJGZ20220011,SJGZ20220012,and SJGZY2024008。
文摘In response to the current issues in the construction of software engineering(SE)degree granting program,such as insufficient resource integration,low level of internationalization,and inadequate quality control,we propose the Software Engineering Degree Granting Program Construction Practice Project at Harbin Institute of Technology(HIT).This project aims to explore new models for software talent cultivation,establish a superior SE degree granting program,and ultimately cultivate outstanding internationalized composite SE professionals to support the high-quality development of the national software industry.To this end,we design a distinctive overall construction idea and plan for the SE degree granting program,which are characterized by“3I3S:three highlights for specialized cultivation and strictness in three aspects to ensure quality control”.After years of practice and validation of the project at the School of Software at HIT,this project has proven effective in optimizing talent cultivation models,enhancing students’practical abilities,promoting international exchange and cooperation,advancing industry-education integration,and meeting industrial needs.
基金supported by the National Natural Science Foundation of China(42474003,42074007)the Fundamental Research Funds for the Central Universities(2042023kfyq01)。
文摘As a major fault in the northeastern Qinghai-Xizang Plateau,the Haiyuan fault zone is important for understanding the regional deformation.Aiming at the differences in the slip rate and locking degree obtained from different studies,this study constructs a refined block model(including Qilian,Alxa,Ordos,Xining,Haiyuan,and Lanzhou blocks)and uses the grid search and simulated annealing methods to invert GPS data for slip rate and locking degree of the Haiyuan fault zone.The results are as follows:(1)The sinistral slip rates in the western,middle,and eastern segments are 4.93-5.22 mm/a,1.52-4.94 mm/a,and 0.43-1.18 mm/a,decreasing eastward on the whole,while the compression rates are 0.45-1.26 mm/a,0.58-2.62 mm/a,and3.52-4.48 mm/a,increasing eastward on the whole.(2)The locking depth of the western segment increases from about 5 km to about 20 km eastward;the middle segment decreases and then increases eastward;the eastern segment concentrates at about 20 km(PHI is about 0.86).(3)The slip deficit is relatively higher in the Lenglongling,Jinqianghe,Maomaoshan,and Liupanshan faults(averaging about 3.42 mm/a,4.16 mm/a,4.23 mm/a,and 3.43 mm/a within 20 km).(4)The Qilian,Alxa,Xining,Lanzhou,and Haiyuan blocks rotate clockwise,while the Ordos block rotates counterclockwise.Additionally,by comparing different block models,the Haiyuan block should be considered independently.The Haiyuan fault zone adjusts surrounding block movements and uplifts Liupanshan mountain tectonically.The results can provide important references for understanding the regional earthquake risk and deformation mechanism.
基金funded by the National College Students Innovation and Entrepreneurship Training Program(202411646031)the Zhejiang Xinmiao Talents Program(2024R405A052)the SRIP Research Program of Ningbo University(2025SRIP1707).
文摘The dynamic behavior of high-speed craft navigating through variable sea states plays a pivotal role in ensuring maritime safety.However,many existing simulation approaches rely on linear or overly simplified representations of the marine environment,thereby limiting the fidelity of motion predictions.This study explores the motion characteristics of a 4.5-t high-speed vessel by conducting fully coupled numerical simulations using the STAR-CCM+software.The analysis considers both calm and varying sea conditions,incorporating fluctuations in wave height,wavelength,and wind speed to reflect more realistic operating scenarios.Simulation results reveal that the vessel’s hydrodynamic response is highly sensitive to changes in sea state.As conditions deteriorate,the free surface becomes increasingly complex,with higher wave amplitudes and more pronounced interactions between the waves generated by the vessel and those imposed by the external environment.These effects lead to significant increases in roll,pitch,heave,and sway motions,thereby imposing greater demands on the vessel’s dynamic stability and operational safety.Furthermore,both hydrodynamic resistance and propulsive thrust exhibit notable dependence on sea state and vessel speed.Total resistance generally increases with rougher sea conditions,while thrust tends to rise with increasing forward speed.Under calm or mildly disturbed waters,a Froude number(Fr)of 0.5 appears to offer an optimal balance for initiating and controlling primary motions such as roll,pitch,heave,and sway.Conversely,in more challenging conditions-such as those represented by a Sea State 3-effective motion control is better achieved at a higher Froude number of approximately 1.0.
基金supported by the National Natural Science Foundation of China(Grant No.62173065)the Natural Science Foundation of Beijing(Grant No.4242040)+1 种基金the Intelligent Policing and National Security Risk Management Laboratory Open Topics for the year 2025(Grant No.ZHKFYB2503)the Intelligent Policing and National Security Risk Management Laboratory Open Topics for the year 2024(Grant No.ZHKFZD2401).
文摘Identifying critical nodes is a pivotal research topic in network science,yet the efficient and accurate detection of highly influential nodes remains a challenge.Existing centrality measures predominantly rely on local or global topological structures,often overlooking indirect connections and their interaction strengths.This leads to imprecise assessments of node importance,limiting practical applications.To address this,we propose a novel node centrality measure,termed six-degree gravity centrality(SDGC),grounded in the six degrees of separation theory,for the precise identification of influential nodes in networks.Specifically,we introduce a set of node influence parameters—node mass,dynamic interaction distance,and attraction coefficient—to enhance the gravity model.Node mass is calculated by integrating K-shell and closeness centrality measures.The dynamic interaction distance,informed by the six-degrees of separation theory,is determined through path searches within six hops between node pairs.The attraction coefficient is derived from the difference in K-shell values between nodes.By integrating these parameters,we develop an improved gravity model to quantify node influence.Experiments conducted on nine real-world networks demonstrate that SDGC significantly outperforms nine existing classical and state-of-the-art methods in identifying the influential nodes.
基金Supported by Hubei Provincial Department of Science and Technology Natural Fund,No.2024AFC056the Open Fund of the Mental Health Research Institute at Three Gorges University,No.YCXL-23-11.
文摘BACKGROUND Major depressive disorder(MDD)with comorbid anxiety is an intricate psychiatric condition,but limited research is available on the degree centrality(DC)between anxious MDD and nonanxious MDD patients.AIM To examine changes in DC values and their use as neuroimaging biomarkers in anxious and non-anxious MDD patients.METHODS We examined 23 anxious MDD patients,30 nonanxious MDD patients,and 28 healthy controls(HCs)using the DC for data analysis.RESULTS Compared with HCs,the anxious MDD group reported markedly reduced DC values in the right fusiform gyrus(FFG)and inferior occipital gyrus,whereas elevated DC values in the left middle frontal gyrus and left inferior parietal angular gyrus.The nonanxious MDD group exhibited surged DC values in the bilateral cerebellum IX,right precuneus,and opercular part of the inferior frontal gyrus.Unlike the nonanxious MDD group,the anxious MDD group exhibited declined DC values in the right FFG and bilateral calcarine(CAL).Besides,declined DC values in the right FFG and bilateral CAL negatively correlated with anxiety scores in the MDD group.CONCLUSION This study shows that abnormal DC patterns in MDD,especially in the left CAL,can distinguish MDD from its anxiety subtype,indicating a potential neuroimaging biomarker.
文摘Objective:To analyze the treatment effect of standardized bronchoscopic interventional therapy(i.e.,interventional therapy)on airway stenosis.Methods:Forty patients with airway stenosis admitted to the hospital between September 2022 and September 2024 were selected and randomly divided into two groups using a random number table.The experimental group received interventional therapy,while the reference group received conventional treatment.The total effective rate,degree of airway stenosis,shortness of breath score,and lung function indicators were compared.Results:The total effective rate in the experimental group was higher than that in the reference group.The proportion of mild stenosis in the degree of airway stenosis was higher in the experimental group than in the reference group.The shortness of breath score was lower in the experimental group than in the reference group.The lung function indicators were better in the experimental group than in the reference group(P<0.05).Conclusion:Interventional therapy is effective for patients with airway stenosis,as it can reduce the degree of stenosis,improve symptoms of shortness of breath,and protect patients’lung function.
基金the Youth Foundation of Fujian Provincial Health Commission,No.2021QNA014the Construction Project of Fujian Province Minimally Invasive Medical Center,No.[2021]76.
文摘BACKGROUND The degree of obstruction plays an important role in decision-making for obstructive colorectal cancer(OCRC).The existing assessment still relies on the colorectal obstruction scoring system(CROSS)which is based on a comprehensive analysis of patients’complaints and eating conditions.The data collection relies on subjective descriptions and lacks objective parameters.Therefore,a scoring system for the evaluation of computed tomography-based obstructive degree(CTOD)is urgently required for OCRC.AIM To explore the relationship between CTOD and CROSS and to determine whether CTOD could affect the short-term and long-term prognosis.METHODS Of 173 patients were enrolled.CTOD was obtained using k-means,the ratio of proximal to distal obstruction,and the proportion of nonparenchymal areas at the site of obstruction.CTOD was integrated with the CROSS to analyze the effect of emergency intervention on complications.Short-term and long-term outcomes were compared between the groups.RESULTS CTOD severe obstruction(CTOD grade 3)was an independent risk factor[odds ratio(OR)=3.390,95%confidence interval(CI):1.340-8.570,P=0.010]via multivariate analysis of short-term outcomes,while CROSS grade was not.In the CTOD-CROSS grade system,for the non-severe obstructive(CTOD 1-2 to CROSS 1-4)group,the complication rate of emergency interventions was significantly higher than that of non-emergency interventions(71.4%vs 41.8%,P=0.040).The postoperative pneumonia rate was higher in the emergency intervention group than in the non-severe obstructive group(35.7%vs 8.9%,P=0.020).However,CTOD grade was not an independent risk factor of overall survival and progression-free survival.CONCLUSION CTOD was useful in preoperative decision-making to avoid unnecessary emergency interventions and complications.
基金National Natural Science Foundation of China (61773044,62073009)National key Laboratory of Science and Technology on Reliability and Environmental Engineering(WDZC2019601A301)。
文摘Delay aware routing is now widely used to provide efficient network transmission. However, for newly developing or developed mobile communication networks(MCN), only limited delay data can be obtained. In such a network, the delay is with epistemic uncertainty, which makes the traditional routing scheme based on deterministic theory or probability theory not applicable. Motivated by this problem, the MCN with epistemic uncertainty is first summarized as a dynamic uncertain network based on uncertainty theory, which is widely applied to model epistemic uncertainties. Then by modeling the uncertain end-toend delay, a new delay bounded routing scheme is proposed to find the path with the maximum belief degree that satisfies the delay threshold for the dynamic uncertain network. Finally, a lowEarth-orbit satellite communication network(LEO-SCN) is used as a case to verify the effectiveness of our routing scheme. It is first modeled as a dynamic uncertain network, and then the delay bounded paths with the maximum belief degree are computed and compared under different delay thresholds.
基金supported by the Key R&D Program of Shandong Province,China(No.2021ZLGX04)the National Natural Science Foundation of China(No.52171284)。
文摘The interaction between regular waves and an oscillating wave energy converter(WEC)in front of a vertical seawall is investigated using a 2D analytical model.A three-degree of freedom(DOF)WEC and a WEC hinged to the seawall(constrained to pitch mode)are considered to examine the influence of the DOF of the WEC on the wave energy extraction performance.Results show that the piston-mode water resonance in the gap and the coupled WEC and water column resonant motion significantly influence the wave energy extraction efficiency.At low frequency,the case with a 3-DOF WEC has a broader high-efficiency bandwidth than that with a heaving WEC.However,3-DOF WEC exhibits worse performance at high frequencies.The frequency response of the wave energy capture width ratio(CWR)for the pitching WEC case shows a trimodal trend under the specified conditions.It showcases the best overall wave energy extraction performance in terms of the high-efficiency bandwidth.Furthermore,a parametric study indicates that the gap distance between the WEC and the seawall has tremendous effects on the CWR of both cases.As the position of the hinge point of the pitching WEC changes,the CWR at the low and high frequencies shows opposite trends.
基金supported in part by the key project supported by the Joint Funds of the National Natural Science Foundation of China(grant No.U2433210)Shaanxi Province Postdoctoral Science Foundation(2024BSHSDZZ225)+1 种基金Natural Science Basic Research Program of Shaanxi Province(2025JC-YBQN-595)the Fundamental Research Funds for the Central Universities,CHD(300102215102).
文摘The use of hot recycled asphalt mixture(HRAM)allows for a reduction in the depletion of non-renewable resources and presents environmental benefits.However,concerns arise regarding the performance of HRAM due to the lower degree of blending(DOB)of virgin and aged asphalt(V&A asphalt).This paper aims to provide an up-to-date review on the DOB of V&A asphalt in HRAM.Initially,the paper introduces the DOB of V&A asphalt,followed by an analysis of the blending theory,evaluation methods,and influencing factors of DOB.Subsequently,the effect of DOB on the performance of HRAM is investigated,and molecular dynamic simulation is utilized to analyze the blend of V&A asphalt.Finally,methods for improving DOB are summarized.It was found that the use of high-resolution microscopy with tracer methods such as SEM/EDS was an effective way to characterize DOB.Furthermore,the chemical composition and colloid structure between virgin and aged asphalt are crucial to DOB.Additionally,improving DOB by utilizing the coupling effect of time and temperature during transportation,paving,and compaction stages is promising.Future research should focus on standardizing test methods,refining field simulation models,and developing intelligent construction technologies to achieve more efficient and durable blending.This review provides theoretical guidance and practical references for improving the DOB of V&A asphalt and promoting sustainable pavement construction.
基金support provided by the research funds from the Hong Kong Research Grants Council(Grant Nos.16206623,N_HKUST603/22,and C6006-20G).
文摘Correctly tracking the evolution of spatial heterogeneity of local degree of saturation(Sr)in unsaturated soils is essential to explain the seepage phenomenon,which is crucial to assessing slope stability.Several methods exist for quantifying the heterogeneity of local S_(r).However,a comprehensive comparison of these methods in terms of accuracy,relative advantages,and disadvantages is currently lacking.This paper presents a comparative analysis of local Sr obtained at multiple scales,ranging from the element scale to the slice,representative element volume(REV),pore,and voxel scales.The spatial heterogeneity of Sr in an unsaturated glass beads specimen at different matric suctions was visualised and quantified by multiscale X-ray micro-focus computed tomography image-based analysis methods.Local Sr obtained at different scales displayed a comparable trend along the sample depth,yet the REV-scale method showed a much scattered and discontinuous distribution.In contrast,the pore-scale method detected a distinct two-clustered,bimodal distribution of S_(r).The pore-scale method has the highest integrated resolution,as it has the highest spatial resolution(i.e.number of data points)and provides more information(i.e.number of extractable physical parameters).This method thus provides a more effective approach for tracking the spatial heterogeneity of S_(r).Based on this method,pore-scale water retention curves were determined,offering new quantitative means to characterise pore water heterogeneity and explainwater drainage processes such as hysteresis at the pore scale.
文摘This paper aims to evaluate the stochastic response of steel columns subjected to blast loads using the modified single degree of freedom(MSDOF)method,which assessed towards the conventional single degree of freedom(SDOF)and the experimentally validated Finite Element(FE)methods(LSDYNA).For this purpose,special atten-tion is given to calculating the response of H-shaped steel columns under blast.The damage amount is determined based on the support rotation criterion,which is expressed as a function of their maximum lateral mid-span dis-placement.To account for uncertainties in input parameters and obtain the failure probability,the Monte Carlo simulation(MCS)method is employed,complemented by the Latin Hypercube Sampling(LHS)method to reduce the number of simulations.A parametric analysis is hence performed to examine the effect of several input pa-rameters(including both deterministic and probabilistic parameters)on the probability of column damage as a function of support rotation.First,the MSDOF method confirms its higher accuracy in estimating the probability of column damage due to blast,compared to the conventional SDOF.The collected results also show that un-certainties of several input parameters have significant effects on the column behavior.In particular,geometric parameters(including cross-sectional characteristics,boundary conditions and column length)have major effect on the corresponding column response,in the same way of input blast load parameters and material properties.
基金supported by the National Natural Science Foundation of China(Grant No.52171261).
文摘A floating horizontal-axis tidal current turbine(HATT)is an underwater power generation device where cavitation inevitably occurs on blade surfaces,severely affecting a turbine’s lifespan.Under wave action,these floating turbines exhibit six degrees of freedom motion,potentially intensifying the cavitation on the blade surfaces.This study selects three types of oscillatory motions from the six degrees of freedom:roll,yaw,and pitch.Computational fluid dynamics(CFD)methods are used for numerical calculations,and transient simulations of multiphase flow are conducted on the basis of the Reynolds-Averaged Navier-Stokes(RANS)model.Research has revealed strong correlations between flow velocity,the blade tip speed ratio,and cavitation.During oscillatory motion,the motion period and amplitude also significantly impact cavitation.In roll motion,the cavitation rate can increase by up to 59%with decreasing period,whereas in pitch and yaw motions,the increases are 7.57 times and 36%larger,respectively.With an increase in amplitude during roll motion,the cavitation rate can increase by up to 1.08 times,whereas in pitch and yaw motions,the increases are 3.49 times and 45%,respectively.The cavitation rate on the blade surfaces is the highest in pitch motion,followed by roll and yaw motions.
基金the financial support received from The Key Project of R&D Program of Ningxia Hui Autonomous Region,China(2022BBF01003)China Agriculture Research System of MOF and MARA(CARS-29).
文摘Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.
基金Hunan Provincial Natural Science Foundation of China(Nos.2022JJ40121,2021JJ40153 and 2021JJ50108)Scientific Research Fund of Hunan Provincial Education Department(Nos.21B0657,22A0518).
文摘In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and subsequent annealing.Due to the identical metal core,these nanoparticles exhibite a similar permeability,but significantly varying permittivity depending on how much C shells have been graphi-tized.It was discovered that proper graphitization of Fe-C nanoparticles annealed at 1350 ℃ can pro-duce excellent microwave absorption(MA),decent dielectric loss tangent in high frequency region,and moderately strong dielectric loss and attenuation properties.Furthermore,the threshold value of 1/ω is discovered to be a crucial parameter in the theoretical analysis of nonlinear behavior of polarization loss,and thus MA performance of the nanoparticles.This research offers a useful method for creating metal-C nanoparticles with various levels of C shell graphitization.It also provides a clear answer to the crucial question of how the level of C shell graphitization affects the MA performance of metal-C nanoparticles.These results may serve as a reference for the development and mechanism analysis of highly effective metal-C based absorbers.
基金financially supported by the National Natural Science Foundation of China(Nos.11704081,52125205,52250398,U20A20166,52192614 and 52003101)Guangxi Natural Science Foundation(Nos.2020GXNSFAA297182,2020GXNSFAA297041 and 2017GXNSFBA19-8229)+5 种基金the special fund for Guangxi Bagui ScholarsNational Science and Technology Innovation Talent Cultivation Program(No.2023BZRC016)National Key R&D Program of China(Nos.2021YFB3200302 and2021YFB3200304)the Natural Science Foundation of Beijing Municipality(No.2222088)Shenzhen Science and Technology Innovation Program(No.KQTD20170810105439418)the Fundamental Research Funds for the Central Universities。
文摘Polarization upconversion luminescence(PUCL)of lanthanide ions(Ln^(3+))has been widely used in single particle tracking,microfluidics detection,three-dimensional displays,and so on.However,no effective strategy has been developed for modulating PUCL.Here we report a strategy to regulate PUCL in Ho^(3+)-doped NaYF4single nanorods based on the number of upconversion photons.By constructing a multiphoton upconversion system for Ho^(3+),we regulate the degree of polarization(DOP)of PUCL from 0.590 for two-photon luminescence to 0.929 for three-photon upconversion luminescence(UCL).Furthermore,our strategy is verified from cross-relaxation between Ho^(3+)and Yb^(3+),excitation wavelength,excitation power density,and local site symmetry.And this regulation strategy of PUCL has also been achieved in Tm^(3+),with the DOP ranging from 0.233 for two-photon luminescence to 0.925 for four-photon UCL Besides,multi-dimensional anti-counterfeiting display has been explored with PUCL.This work provides an effective strategy for regulating PUCL and also provides more opportunities for the development of polarization display optical encoding,anti-counterfeiting,and integrated optical devices.
基金Supported by NSFC(No.12011530064)Natural Science Foundation of Shanghai(No.22ZR1416300)。
文摘Let G be a graph on n vertices whose degree sequence is d_(1)≥…≥d_(n).For a positive integer p,the degree power of G is defined by e_p(G)=∑_(i=1)^(n) d_(i)^(p).In this paper,by majorization,we prove that for a minimally k-connected graph G of order n≥4k,it always holds e_(2)(G)≤kn(n-k)and the extremal graph is K_(k,n-k).Furthermore,we respectively determine the maximum degree powers among all minimally 2(3)-connected graphs and minimally 2-edgeconnected graphs,whose extremal graphs are also characterized.
基金funded by the National Natural Science Foundation of China(No.41972264)Zhejiang Provincial Natural Science Foundation of China(No.LR22E080002)the Key R&D Project of Zhejiang Province(No.2021C03159).
文摘Flexural toppling occurs when a series of layered rock masses bend towards their free face.It is important to evaluate the maximum bending degree and the requirement of supports of flexural toppling rock mass to prevent rock mass cracking and even failure leading to a landslide.Based on the rock tensile strain-softening model,this study proposes a method for calculating the maximum curvature(C_(ppmax))of flexural toppling rock masses.By applying this method to calculate Cppmax of 9 types of rock masses with different hardness and rock layer thickness,some conclusions are drawn:(1)the internal key factors affecting C_(ppmax)are E^(⋆)(E^(⋆)=E_(ss)/E_(0),where E_(0)and E_(ss)are the mean deformation moduli of the rock before and after reaching its peak tensile strength,respectively),the strainεt corresponding to the tensile strength of rock,and the thickness(h)of rock layers;(2)hard rock layers are more likely to develop into block toppling than soft rock layers;and(3)thin rock layers are more likely to remain in flexural toppling state than thick rock layers.In addition,it is found that C_(ppmax)for flexural toppling rock masses composed of bedded rocks such as gneiss is related to the tensile direction.
