The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analy...The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analysis of wind pressure on the membrane roof is conducted first and then an analysis of the wind-induced responses of the structure is carried out using a numerical integral method in the time domain. In the process of calculation, the geometrical nonlinearity is taken into account. Results indicate that mean, RSM and peak values of the structure responses increase nonlinearly while the approaching flow velocity increases. Strong nonlinear characteristics are observed in the displacement responses, whereas the responses of nodal stress and cable axial force show minimal nonlinear properties when the membrane structure is subjected to wind loads. Different values of the damping ratio only have a minimal impact on the RSM response of the structure because the background component is a dominant part of the total dynamic response and the resonant component is too small. As the damping ratio increases from 0.02 to 0.05, the RMS responses of vertical displacement, nodal stress and cable axial force decrease by 8.1%, 6.7% and 17.9%, respectively. Since the mean component plays a significant role in the wind-induced response, the values of the gust response factor are not high for Expo Boulevard.展开更多
Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formula...Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads(ESWLSs)were derived based on structural dynamics and random vibration theory.The consistent coupled method(CCM)was presented to compensate the coupled term between background and resonant response.Taking the super-large cooling tower(H=215 m)of nuclear power plant in Jiangxi Province,China,which is the highest and largest in China,as the example,based on modified equivalent beam-net design method,the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out.Then,combining wind tunnel test and CCM,the effects of self-excited force on the surface pressures and wind-induced responses are discussed,and the wind-induced response characteristics of background component,resonant component,coupled term between background and resonant response,fluctuating responses,and wind vibration coefficients are discussed.It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers.展开更多
For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise...For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise buildings are very sensitive to fluctuating wind. The wind load is one of the key loads in the design of super high-rise buildings. It is known that only the basic mode is needed in the wind-response analysis of tall buildings. However, for super high-rise buildings, especially for the acceleration response, because of the frequency amplification of the high modes, the high modes and the mode coupling may need to be considered. Three typical super high-rise projects with the SMPSS in wind tunnel tests and the random vibration theory method were used to analyze the effect of high modes on the wind-induced response. The conclusions can be drawn as follows. First, for the displacement response, the basic mode is dominant, and the high modes can be neglected. Second, for the acceleration response, the high modes and the mode coupling should be considered. Lastly, the strain energy of modes can only give the vibration energy distribution of the high-rise building, and it cannot describe the local wind-induced vibration of high-rise buildings, especially for the top acceleration response.展开更多
Conical membrane structures are a typical form of tensile membrane structures. In the past, most studies focused on the static performance, but few on dynamic performance. In this paper, systematic parameter analysis ...Conical membrane structures are a typical form of tensile membrane structures. In the past, most studies focused on the static performance, but few on dynamic performance. In this paper, systematic parameter analysis of wind-induced response of conical membrane structures has been performed with nonlinear random simulation method in a time domain, by considering some parameters, such as span, rise-span ratio, prestress of membrane, and characteristic of the approaching wind flow. Moreover, formulas of the dynamic coefficient and nonlinear adjustment factor are advised, which can be conveniently used in wind-resistant design of conical membrane structures.展开更多
The main objectives of the research are to characterize the wind-induced resonant and slowly-varying (quasi-static) responses of a tall building under ambient wind excitations based on GPS measurements. The equipment ...The main objectives of the research are to characterize the wind-induced resonant and slowly-varying (quasi-static) responses of a tall building under ambient wind excitations based on GPS measurements. The equipment used includes two sets of orthogonally aligned accelerometers, two GPS receivers and an ultrasonic anemometer. The natural frequencies of the wind-induced vibration of the tall building are determined by carrying out spectral analysis of the measured time series of acceleration. The time series are also used to estimate the structural damping with the random decrement technique (RDT). The results show that GPS can be effectively used to measure the resonant and slowly-varying responses of tall buildings with 3D mode shapes under wind excitations. The results from the GPS and the accelerometers agree well with each other in both the time and frequency domains.展开更多
The displacement of transmission tower feet can seriously affect the safe operation of the tower,and the accuracy of structural health monitoring methods is limited at the present stage.The application of deep learnin...The displacement of transmission tower feet can seriously affect the safe operation of the tower,and the accuracy of structural health monitoring methods is limited at the present stage.The application of deep learning method provides new ideas for structural health monitoring of towers,but the current amount of tower vibration fault data is restricted to provide adequate training data for Deep Learning(DL).In this paper,we propose a DT-DL based tower foot displacement monitoring method,which firstly simulates the wind-induced vibration response data of the tower under each fault condition by finite element method.Then the vibration signal visualization and Data Transfer(DT)are used to add tower fault data samples to solve the problem of insufficient actual data quantity.Subsequently,the dynamic response test is carried out under different tower fault states,and the tower fault monitoring is carried out by the DL method.Finally,the proposed method is compared with the traditional online monitoring method,and it is found that this method can significantly improve the rate of convergence and recognition accuracy in the recognition process.The results show that the method can effectively identify the tower foot displacement state,which can greatly reduce the accidents that occurred due to the tower foot displacement.展开更多
BACKGROUND Gallbladder cancer(GBC)is the most common and aggressive subtype of biliary tract cancer(BTC)and has a poor prognosis.A newly developed regimen of gemcitabine,cisplatin,and durvalumab shows promise for the ...BACKGROUND Gallbladder cancer(GBC)is the most common and aggressive subtype of biliary tract cancer(BTC)and has a poor prognosis.A newly developed regimen of gemcitabine,cisplatin,and durvalumab shows promise for the treatment of advanced BTC.However,the efficacy of this treatment for GBC remains unclear.CASE SUMMARY In this report,we present a case in which the triple-drug regimen exhibited marked effectiveness in treating locally advanced GBC,thus leading to a long-term survival benefit.A 68-year-old man was diagnosed with locally advanced GBC,which rendered him ineligible for curative surgery.Following three cycles of therapy,a partial response was observed.After one year of combined therapy,a clinical complete response was successfully achieved.Subsequent maintenance therapy with durvalumab monotherapy resulted in a disease-free survival of 9 months for the patient.The patient experienced tolerable toxicities of reversible grade 2 nausea and fatigue.Tolerable adverse events were observed in the patient throughout the entirety of the treatment.CONCLUSION The combination of gemcitabine and cisplatin chemotherapy with durvalumab was proven to be an effective treatment approach for advanced GBC,with manageable adverse events.Further research is warranted to substantiate the effectiveness of the combined regimen in the context of GBC.展开更多
Projective synchronization problems of a drive system and a particular response network were investigated,where the drive system is an arbitrary system with n+1 dimensions;it may be a linear or nonlinear system,and ev...Projective synchronization problems of a drive system and a particular response network were investigated,where the drive system is an arbitrary system with n+1 dimensions;it may be a linear or nonlinear system,and even a chaotic or hyperchaotic system,the response network is complex system coupled by N nodes,and every node is showed by the approximately linear part of the drive system.Only controlling any one node of the response network by designed controller can achieve the projective synchronization.Some numerical examples were employed to verify the effectiveness and correctness of the designed controller.展开更多
Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted t...Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.展开更多
Accumulating evidence indicates that antibiotic exposure may lead to impaired vaccine responses1-4;however,the mechanisms underlying this association remain poorly understood.Here we prospectively followed 191 healthy...Accumulating evidence indicates that antibiotic exposure may lead to impaired vaccine responses1-4;however,the mechanisms underlying this association remain poorly understood.Here we prospectively followed 191 healthy,vaginally born,term infants from birth to 15 months,using a systems vaccinology approach to assess the effects of antibiotic exposure on immune responses to vaccination.Exposure to direct neonatal but not intrapartum antibiotics was associated with significantly lower antibody titres against various polysaccharides in the 13-valent pneumococcal conjugate vaccine and the Haemophilus influenzae type b polyribosylribitol phosphate and diphtheria toxoid antigens in the combined 6-in-1 Infanrix Hexa vaccine at 7 months of age.Blood from infants exposed to neonatal antibiotics had an inflammatory transcriptional profile before vaccination;in addition,faecal metagenomics showed reduced abundance of Bifidobacterium species in these infants at the time of vaccination,which was correlated with reduced vaccine antibody titres 6 months later.In preclinical models,responses to the 13-valent pneumococcal conjugate vaccine were strongly dependent on an intact microbiota but could be restored in germ-free mice by administering a consortium of Bifidobacterium species or a probiotic already widely used in neonatal units.Our data suggest that microbiota-targeted interventions could mitigate the detrimental effects of early-life antibiotics on vaccine immunogenicity.展开更多
Objective To investigate whether 2,3,5,4'-tetrahydroxystilbene-2-O-β-glucoside(TSG)ameliorated polycystic ovary syndrome(PCOS)-like characteristics by inhibiting inflammation.Methods PCOS models were established ...Objective To investigate whether 2,3,5,4'-tetrahydroxystilbene-2-O-β-glucoside(TSG)ameliorated polycystic ovary syndrome(PCOS)-like characteristics by inhibiting inflammation.Methods PCOS models were established by injecting subcutaneously with dehydroepiandrosterone into female Sprague-Dawley rats,followed by receiving intraperitoneal injection of TSG.The granular cells(GCs)KGN were transfected with small interfering RNAs(si-NC and si-CYP19A1).The cells were preincubated with lipopolysaccharide(LPS)and then treated with or without TSG.The estrous cycle was monitored using vaginal exfoliated cells.The morphology of ovarian follicles was analyzed by H&E staining.ELISA was used to analyze estradiol(E2),testosterone(T),follicle stimulating hormone(FSH),luteinizing hormone(LH),IL-6,TNF-α,AGEs,CRP and Omentin-1 levels in serum.Immunohistochemistry was performed to analyze PCNA and CYP19A1 expressions in the GCs of ovaries.Tunel staining was executed to detect the apoptosis of GCs.Quantitative polymerase chain reaction(qPCR)and Western blot were implemented to measure the expression of CYP19A1 in the ovaries and transfected cells.qPCR was used to analyze the expression of IL-6 and TNF-αin the transfected cells treated with LPS and TSG.Results The estrous cycles were restored in TSG group.Compared with model group,the sinus follicles were reduced and corpus luteums were increased in TSG group.TSG group showed increased E2,and decreased T and LH,compared with model group.Pro-inflammatory factors(IL-6,TNF-α,CRP and AGEs)were decreased,and anti-inflammatory factor(Omentin-1)was increased in TSG group compared with those in model group.TSG could partially inhibit decrease of PNCA-positive GCs and increase of Tunel-positive GCs caused by PCOS.The CYP19A1 expression of GCs in TSG group was upregulated compared with model group.The expressions of IL-6 and TNFαin si-CYP19A1 cells were increased compared with si-NC cells.Compared with cells(si-NC and si-CYP19A1)treated without LPS,the expressions of IL-6 and TNF-αcells were increased,and the expression of CYP19A1 was downregulated in LPS-preincubated cells.Compared with cells treated with LPS,the expression of IL-6 and TNF-αwere decreased,and the expression of CYP19A1 was increased in cells treated with LPS and TSG.Compared with si-NC cells treated with LPS and TSG,the expressions of IL-6 and TNF-αcells were increased in the si-CYP19A1 cells treated with LPS and TSG.Conclusion TSG could alleviate PCOS-like characteristics by increasing the expression of CYP19A1 in GCs to inhibit inflammatory response.展开更多
Objective:The aim of the study was to evaluate the feasibility of functional MR in predicting the clinical response to chemotherapy in patients with colorectal liver metastases(CLM).Methods:A total of 196 eligible pat...Objective:The aim of the study was to evaluate the feasibility of functional MR in predicting the clinical response to chemotherapy in patients with colorectal liver metastases(CLM).Methods:A total of 196 eligible patients were enrolled in the study between August 2016 and January 2023.Functional MR was performed at baseline and after one cycle of chemotherapy.The diffusion kurtosis radiomic texture features were extracted and a signature model was built using the R package.The initial 100 cases were designated as the training set,the following 48 cases were designated as the validation set,and the final 48 cases were designated as the intervention validation set.Results:Good performance for the response prediction(AUC=0.818 in the training set and 0.755 in the validation set)was demonstrated.The objective response rates(ORRs)in the high-risk subgroup were significantly lower than the low-risk subgroup in the training and validation sets.Worse progression-free survival and overall survival rates were noted in the high-risk population.In the intervention set 22.9%(11/48)of the chemotherapy regimens for patients were changed in response to the model-predicted results and the ORR reached 77.1%(37/48),which was significantly higher than the training and validation sets[47.97%(71/148);P=0.000].Conclusions:A functional MR signature effectively predicted the chemotherapy response and long-term survival.The adjustment of the regimen guided by the model significantly improved the ORR.展开更多
This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-...This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-pinned,fixed-pinned,fixed-free(or cantilever),and fixed-fixed.Appendages considered include lumped masses,dampers,and springs.The modal decomposition method is employed to derive the equation of motion of the beam,for which an analytical closed-form expression of the dynamic vibration response is generated.The proposed method enables the study of the effect of a single appendage or a combination of the three types of appendages on the non-dimensional dynamic response of the beam.Numerical examples are presented to illustrate the effects of these appendages and compare them to the reference cases of a beam with no appendages.The results demonstrate the importance of considering these parameters in the design of structures.The proposed method is compared to other techniques in the literature and found to be advantageous due to its direct approach.The method also offers a versatile tool for investigating various configurations,aiding in engineering design and structural analysis for which establishing a precise prediction of beam vibrations is crucial.展开更多
Tree canopy landscapes are an important component of urban forests and have the potential to influence human emotions.However,their influence on emotional responses remains unclear.The aims of this study were:(1)to de...Tree canopy landscapes are an important component of urban forests and have the potential to influence human emotions.However,their influence on emotional responses remains unclear.The aims of this study were:(1)to determine whether the canopy landscape affects human emotions;(2)to clarify the influence of canopy landscape on individual emotional indicators;and(3)to identify the ratio of canopy landscape elements with the most beneficial effects on human emotions.Different canopy landscape images were generated,and the self-reported emotions and neural activity of the subjects assessed before and after they viewed the images.The results of the statistical analysis were intuitively displayed by a ternary phase diagram.We found that the canopy landscape affected human emotions and different proportions of canopy landscape elements led to significant differences in excitement,depression and confusion.Higher proportions of blue elements and lower proportions of green and other elements characterized the canopy landscape with the most beneficial effect on human emotions.These findings will promote further research on canopy landscapes,inform the planning and design of urban forests,and contribute to the field of landscape architecture.展开更多
Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical ap...Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical applications,the deployment of flexible pressure sensors characterized by high sensitivity and fast response time is imperative for the rapid and accurate detection and monitoring of tiny signals.Such capabilities are essential for facilitating immediate feedback and informed decision-making across a spectrum of contexts.Drawing lessons from the hypersensitive and fast-responding pressure sensing structures in the dragonfly’s neck(for stable imaging during its highly maneuverable flight),a Biomimetic Piezoresistive Pressure Sensor(BPPS)with exquisite mechanically interlocking sensing microstructures is developed.Each interlocking perceptual structure pair consists of an ox-horn-shaped and a mushroom-shaped structural unit.Through the characteristic configuration of the perceptual structure pair,the BPPS realizes a fast gradient accumulation of the contact area,thus synergistically enhancing the sensitivity and fast response capability.Remarkably,the sensitivity of the BPPS reaches 0.35 kPa^(−1),which increased by 75%compared to the 0.2 kPa^(−1) of the pressure sensors without biomimetic structures.Moreover,the BPPS also achieves rapid response/recovery times(<90/15 ms).Our BPPS finds utility in tasks such as identifying objects of different weights,monitoring human respiratory status,and tracking motion,demonstrating its potential in wearable healthcare devices,assistive technology,and intelligent soft robotics.Moreover,it possesses the advantages of high sensitivity and fast response time in practical applications.展开更多
The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with...The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.展开更多
Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune res...Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune responses.Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health.However,the regulatory mechanisms of sRNAs in P.plecoglossicida remain unclear.This study focused on sRNA113,previously identified as a potential regulator of the fliP gene,a key component of the lateral flagellar type III secretion system.To investigate the effects of sRNA113on P.plecoglossicida virulence,as well as its role in regulating pathogenic processes and host immune responses,mutant strains lacking this sRNA were generated and analyzed.Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P.plecoglossicida,which enhanced bacterial swarming motility,biofilm formation,and chemotaxis ability in vitro.In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P.plecoglossicida.This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system,resulting in higher bacterial loads within host tissues.This amplification of pathogenic activity intensified tissue damage,disrupted immune responses,and impaired the ability of the host to clear infection,ultimately leading to mortality.These findings underscore the critical role of sRNA113 in regulating the virulence of P.plecoglossicida and its interaction with host immune defenses.This study provides a foundation for further exploration of sRNAmediated mechanisms in bacterial pathogenesis and hostpathogen interactions,contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens.展开更多
Flutter and forced response, as two main branches of aeroelasticity, can lead to high-cycle fatigue failure of turbomachinery blades. Efficiently and accurately assessing aeroelastic performance of turbomachinery blad...Flutter and forced response, as two main branches of aeroelasticity, can lead to high-cycle fatigue failure of turbomachinery blades. Efficiently and accurately assessing aeroelastic performance of turbomachinery blades is essential in the routine design. In this work, the Time Collocation Method (TCM) which uses the cubic B-spline to approximate flow variables is first thoroughly studied and then combined with the moving grid technique to analyze aeroelastic flow fields. To showcase its advantage over the Harmonic Balance (HB) method which uses a truncated Fourier series to approximately represent flow variables, a matrix analysis of the one-dimensional advection equation is first performed. The results of stability analysis are verified by two test cases: the Durham linear oscillating turbine cascade and a two-blade-row transonic compressor. The vibration of the blade of the first case is driven by a motor while the excitation force of the second case comes from blade row interaction. The results show that the time collocation method has a faster convergence rate and is more stable than the harmonic balance method, especially for cases with a large maximum grid reduced frequency. More importantly, the time collocation method is capable of accurately predicting aeroelastic performance of turbomachinery blades.展开更多
The use of ultra-high molecular weight polyethylene(UHMWPE)composite in the design of lightweight protective equipment,has gained a lot of interest.However,there is an urgent need to understand the ballistic response ...The use of ultra-high molecular weight polyethylene(UHMWPE)composite in the design of lightweight protective equipment,has gained a lot of interest.However,there is an urgent need to understand the ballistic response mechanism and theoretical prediction model of performance.This paper explores the ballistic response mechanism of UHMWPE composite through experimental and simulation analyses.Then,a resistance-driven modeling method was proposed to establish a theoretical model for predicting the bulletproof performance.The ballistic response mechanism of UHMWPE composite encompassed three fundamental modes:local response,structural response,and coupled response.The occurrence ratio of these fundamental response modes during impact was dependent on the projectile velocity and laminate thickness.The bulletproof performance of laminate under different response modes was assessed based on the penetration depth of the projectile,the bulging height on the rear face of the laminate,the thickness of remaining sub-laminate,and residual velocity of the projectile.The absolute deviations of bulletproof performance indicator between theoretical value and experimental value were well within 11.13%,demonstrating that the established evaluation model possessed high degree of prediction accuracy.展开更多
The strongest earthquake to hit Myanmar in over a century has caused huge damage and numerous deaths since it struck the Southeast Asian country on March 28.As of April 2,the 7.9-magnitude quake had killed 2,886 peopl...The strongest earthquake to hit Myanmar in over a century has caused huge damage and numerous deaths since it struck the Southeast Asian country on March 28.As of April 2,the 7.9-magnitude quake had killed 2,886 people and wounded 4,639,according to official statistics.The numbers are expected to rise as rescue efforts and damage assessments continue.展开更多
基金National Natural Science Foundation under Grant No. 51278368the Fundamental Research Funds for the Central Universities
文摘The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analysis of wind pressure on the membrane roof is conducted first and then an analysis of the wind-induced responses of the structure is carried out using a numerical integral method in the time domain. In the process of calculation, the geometrical nonlinearity is taken into account. Results indicate that mean, RSM and peak values of the structure responses increase nonlinearly while the approaching flow velocity increases. Strong nonlinear characteristics are observed in the displacement responses, whereas the responses of nodal stress and cable axial force show minimal nonlinear properties when the membrane structure is subjected to wind loads. Different values of the damping ratio only have a minimal impact on the RSM response of the structure because the background component is a dominant part of the total dynamic response and the resonant component is too small. As the damping ratio increases from 0.02 to 0.05, the RMS responses of vertical displacement, nodal stress and cable axial force decrease by 8.1%, 6.7% and 17.9%, respectively. Since the mean component plays a significant role in the wind-induced response, the values of the gust response factor are not high for Expo Boulevard.
基金Projects(50978203,51208254)supported by the National Natural Science Foundation of ChinaProject(BK2012390)supported by Natural Science Foundation of Jiangsu Province,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads(ESWLSs)were derived based on structural dynamics and random vibration theory.The consistent coupled method(CCM)was presented to compensate the coupled term between background and resonant response.Taking the super-large cooling tower(H=215 m)of nuclear power plant in Jiangxi Province,China,which is the highest and largest in China,as the example,based on modified equivalent beam-net design method,the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out.Then,combining wind tunnel test and CCM,the effects of self-excited force on the surface pressures and wind-induced responses are discussed,and the wind-induced response characteristics of background component,resonant component,coupled term between background and resonant response,fluctuating responses,and wind vibration coefficients are discussed.It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers.
基金National Natural Science Foundation of China Under Grant No.50908044 Jiangsu Provincial Natural Science Foundation of China Under Grant No.SBK201123270 a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions and StateKey Lab of Subtropical Building Science,South China University of Technology Under Grant No.2011KA05
文摘For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise buildings are very sensitive to fluctuating wind. The wind load is one of the key loads in the design of super high-rise buildings. It is known that only the basic mode is needed in the wind-response analysis of tall buildings. However, for super high-rise buildings, especially for the acceleration response, because of the frequency amplification of the high modes, the high modes and the mode coupling may need to be considered. Three typical super high-rise projects with the SMPSS in wind tunnel tests and the random vibration theory method were used to analyze the effect of high modes on the wind-induced response. The conclusions can be drawn as follows. First, for the displacement response, the basic mode is dominant, and the high modes can be neglected. Second, for the acceleration response, the high modes and the mode coupling should be considered. Lastly, the strain energy of modes can only give the vibration energy distribution of the high-rise building, and it cannot describe the local wind-induced vibration of high-rise buildings, especially for the top acceleration response.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50338010).
文摘Conical membrane structures are a typical form of tensile membrane structures. In the past, most studies focused on the static performance, but few on dynamic performance. In this paper, systematic parameter analysis of wind-induced response of conical membrane structures has been performed with nonlinear random simulation method in a time domain, by considering some parameters, such as span, rise-span ratio, prestress of membrane, and characteristic of the approaching wind flow. Moreover, formulas of the dynamic coefficient and nonlinear adjustment factor are advised, which can be conveniently used in wind-resistant design of conical membrane structures.
文摘The main objectives of the research are to characterize the wind-induced resonant and slowly-varying (quasi-static) responses of a tall building under ambient wind excitations based on GPS measurements. The equipment used includes two sets of orthogonally aligned accelerometers, two GPS receivers and an ultrasonic anemometer. The natural frequencies of the wind-induced vibration of the tall building are determined by carrying out spectral analysis of the measured time series of acceleration. The time series are also used to estimate the structural damping with the random decrement technique (RDT). The results show that GPS can be effectively used to measure the resonant and slowly-varying responses of tall buildings with 3D mode shapes under wind excitations. The results from the GPS and the accelerometers agree well with each other in both the time and frequency domains.
基金supported by the Key Projects of Shaanxi Province Key R&D Program(2018ZDXM-GY-040)supported by Natural Science Foundation of Shaanxi Province,Basic Research Program Project(2019JQ-843)supported by Graduate Scientific Innovation Fund for Xi’an Polytechnic University(chx2023012).
文摘The displacement of transmission tower feet can seriously affect the safe operation of the tower,and the accuracy of structural health monitoring methods is limited at the present stage.The application of deep learning method provides new ideas for structural health monitoring of towers,but the current amount of tower vibration fault data is restricted to provide adequate training data for Deep Learning(DL).In this paper,we propose a DT-DL based tower foot displacement monitoring method,which firstly simulates the wind-induced vibration response data of the tower under each fault condition by finite element method.Then the vibration signal visualization and Data Transfer(DT)are used to add tower fault data samples to solve the problem of insufficient actual data quantity.Subsequently,the dynamic response test is carried out under different tower fault states,and the tower fault monitoring is carried out by the DL method.Finally,the proposed method is compared with the traditional online monitoring method,and it is found that this method can significantly improve the rate of convergence and recognition accuracy in the recognition process.The results show that the method can effectively identify the tower foot displacement state,which can greatly reduce the accidents that occurred due to the tower foot displacement.
基金Supported by General Project of Natural Science Foundation of Chongqing,China,No.cstc2021jcyj-msxmX0604Chongqing Doctoral"Through Train"Research Program,China,No.CSTB2022BSXM-JCX0045.
文摘BACKGROUND Gallbladder cancer(GBC)is the most common and aggressive subtype of biliary tract cancer(BTC)and has a poor prognosis.A newly developed regimen of gemcitabine,cisplatin,and durvalumab shows promise for the treatment of advanced BTC.However,the efficacy of this treatment for GBC remains unclear.CASE SUMMARY In this report,we present a case in which the triple-drug regimen exhibited marked effectiveness in treating locally advanced GBC,thus leading to a long-term survival benefit.A 68-year-old man was diagnosed with locally advanced GBC,which rendered him ineligible for curative surgery.Following three cycles of therapy,a partial response was observed.After one year of combined therapy,a clinical complete response was successfully achieved.Subsequent maintenance therapy with durvalumab monotherapy resulted in a disease-free survival of 9 months for the patient.The patient experienced tolerable toxicities of reversible grade 2 nausea and fatigue.Tolerable adverse events were observed in the patient throughout the entirety of the treatment.CONCLUSION The combination of gemcitabine and cisplatin chemotherapy with durvalumab was proven to be an effective treatment approach for advanced GBC,with manageable adverse events.Further research is warranted to substantiate the effectiveness of the combined regimen in the context of GBC.
基金Supported by the National Natural Science Foundation of China (11161027)。
文摘Projective synchronization problems of a drive system and a particular response network were investigated,where the drive system is an arbitrary system with n+1 dimensions;it may be a linear or nonlinear system,and even a chaotic or hyperchaotic system,the response network is complex system coupled by N nodes,and every node is showed by the approximately linear part of the drive system.Only controlling any one node of the response network by designed controller can achieve the projective synchronization.Some numerical examples were employed to verify the effectiveness and correctness of the designed controller.
基金National Natural Science Foundation of China under Grant No.52278135。
文摘Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.
文摘Accumulating evidence indicates that antibiotic exposure may lead to impaired vaccine responses1-4;however,the mechanisms underlying this association remain poorly understood.Here we prospectively followed 191 healthy,vaginally born,term infants from birth to 15 months,using a systems vaccinology approach to assess the effects of antibiotic exposure on immune responses to vaccination.Exposure to direct neonatal but not intrapartum antibiotics was associated with significantly lower antibody titres against various polysaccharides in the 13-valent pneumococcal conjugate vaccine and the Haemophilus influenzae type b polyribosylribitol phosphate and diphtheria toxoid antigens in the combined 6-in-1 Infanrix Hexa vaccine at 7 months of age.Blood from infants exposed to neonatal antibiotics had an inflammatory transcriptional profile before vaccination;in addition,faecal metagenomics showed reduced abundance of Bifidobacterium species in these infants at the time of vaccination,which was correlated with reduced vaccine antibody titres 6 months later.In preclinical models,responses to the 13-valent pneumococcal conjugate vaccine were strongly dependent on an intact microbiota but could be restored in germ-free mice by administering a consortium of Bifidobacterium species or a probiotic already widely used in neonatal units.Our data suggest that microbiota-targeted interventions could mitigate the detrimental effects of early-life antibiotics on vaccine immunogenicity.
文摘Objective To investigate whether 2,3,5,4'-tetrahydroxystilbene-2-O-β-glucoside(TSG)ameliorated polycystic ovary syndrome(PCOS)-like characteristics by inhibiting inflammation.Methods PCOS models were established by injecting subcutaneously with dehydroepiandrosterone into female Sprague-Dawley rats,followed by receiving intraperitoneal injection of TSG.The granular cells(GCs)KGN were transfected with small interfering RNAs(si-NC and si-CYP19A1).The cells were preincubated with lipopolysaccharide(LPS)and then treated with or without TSG.The estrous cycle was monitored using vaginal exfoliated cells.The morphology of ovarian follicles was analyzed by H&E staining.ELISA was used to analyze estradiol(E2),testosterone(T),follicle stimulating hormone(FSH),luteinizing hormone(LH),IL-6,TNF-α,AGEs,CRP and Omentin-1 levels in serum.Immunohistochemistry was performed to analyze PCNA and CYP19A1 expressions in the GCs of ovaries.Tunel staining was executed to detect the apoptosis of GCs.Quantitative polymerase chain reaction(qPCR)and Western blot were implemented to measure the expression of CYP19A1 in the ovaries and transfected cells.qPCR was used to analyze the expression of IL-6 and TNF-αin the transfected cells treated with LPS and TSG.Results The estrous cycles were restored in TSG group.Compared with model group,the sinus follicles were reduced and corpus luteums were increased in TSG group.TSG group showed increased E2,and decreased T and LH,compared with model group.Pro-inflammatory factors(IL-6,TNF-α,CRP and AGEs)were decreased,and anti-inflammatory factor(Omentin-1)was increased in TSG group compared with those in model group.TSG could partially inhibit decrease of PNCA-positive GCs and increase of Tunel-positive GCs caused by PCOS.The CYP19A1 expression of GCs in TSG group was upregulated compared with model group.The expressions of IL-6 and TNFαin si-CYP19A1 cells were increased compared with si-NC cells.Compared with cells(si-NC and si-CYP19A1)treated without LPS,the expressions of IL-6 and TNF-αcells were increased,and the expression of CYP19A1 was downregulated in LPS-preincubated cells.Compared with cells treated with LPS,the expression of IL-6 and TNF-αwere decreased,and the expression of CYP19A1 was increased in cells treated with LPS and TSG.Compared with si-NC cells treated with LPS and TSG,the expressions of IL-6 and TNF-αcells were increased in the si-CYP19A1 cells treated with LPS and TSG.Conclusion TSG could alleviate PCOS-like characteristics by increasing the expression of CYP19A1 in GCs to inhibit inflammatory response.
基金supported by the National Natural Science Foundation of China(Grant nos.82271946 and 82202101)Innovative Achievement Transformation of Shenkang MedicalEnterprise Integration(Grant no.SHDC2023CRD014)。
文摘Objective:The aim of the study was to evaluate the feasibility of functional MR in predicting the clinical response to chemotherapy in patients with colorectal liver metastases(CLM).Methods:A total of 196 eligible patients were enrolled in the study between August 2016 and January 2023.Functional MR was performed at baseline and after one cycle of chemotherapy.The diffusion kurtosis radiomic texture features were extracted and a signature model was built using the R package.The initial 100 cases were designated as the training set,the following 48 cases were designated as the validation set,and the final 48 cases were designated as the intervention validation set.Results:Good performance for the response prediction(AUC=0.818 in the training set and 0.755 in the validation set)was demonstrated.The objective response rates(ORRs)in the high-risk subgroup were significantly lower than the low-risk subgroup in the training and validation sets.Worse progression-free survival and overall survival rates were noted in the high-risk population.In the intervention set 22.9%(11/48)of the chemotherapy regimens for patients were changed in response to the model-predicted results and the ORR reached 77.1%(37/48),which was significantly higher than the training and validation sets[47.97%(71/148);P=0.000].Conclusions:A functional MR signature effectively predicted the chemotherapy response and long-term survival.The adjustment of the regimen guided by the model significantly improved the ORR.
文摘This paper addresses the problem of a viscoelastic Euler-Bernoulli beam under the influence of a constant velocity moving mass and different types of appendages.Four types of boundary conditions are considered:pinned-pinned,fixed-pinned,fixed-free(or cantilever),and fixed-fixed.Appendages considered include lumped masses,dampers,and springs.The modal decomposition method is employed to derive the equation of motion of the beam,for which an analytical closed-form expression of the dynamic vibration response is generated.The proposed method enables the study of the effect of a single appendage or a combination of the three types of appendages on the non-dimensional dynamic response of the beam.Numerical examples are presented to illustrate the effects of these appendages and compare them to the reference cases of a beam with no appendages.The results demonstrate the importance of considering these parameters in the design of structures.The proposed method is compared to other techniques in the literature and found to be advantageous due to its direct approach.The method also offers a versatile tool for investigating various configurations,aiding in engineering design and structural analysis for which establishing a precise prediction of beam vibrations is crucial.
基金co-funded by the Talent Initiation Program of the Scientific Research Development Fund of Zhejiang A&F University(2021LFR041and 2022LFR040)the National Natural Science Foundation of China(52278084).
文摘Tree canopy landscapes are an important component of urban forests and have the potential to influence human emotions.However,their influence on emotional responses remains unclear.The aims of this study were:(1)to determine whether the canopy landscape affects human emotions;(2)to clarify the influence of canopy landscape on individual emotional indicators;and(3)to identify the ratio of canopy landscape elements with the most beneficial effects on human emotions.Different canopy landscape images were generated,and the self-reported emotions and neural activity of the subjects assessed before and after they viewed the images.The results of the statistical analysis were intuitively displayed by a ternary phase diagram.We found that the canopy landscape affected human emotions and different proportions of canopy landscape elements led to significant differences in excitement,depression and confusion.Higher proportions of blue elements and lower proportions of green and other elements characterized the canopy landscape with the most beneficial effect on human emotions.These findings will promote further research on canopy landscapes,inform the planning and design of urban forests,and contribute to the field of landscape architecture.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)National Natural Science Foundation of China(Nos.52222509,52105301)+1 种基金the Natural Science Foundation of Jilin Province(Grant No.20220101220JC)supported by“Fundamental Research Funds for the Central Universities”.
文摘Flexible piezoresistive pressure sensors have attracted much attention for applications in health monitoring and human-machine interfaces due to their simple device structures and easy-to-read signals.For practical applications,the deployment of flexible pressure sensors characterized by high sensitivity and fast response time is imperative for the rapid and accurate detection and monitoring of tiny signals.Such capabilities are essential for facilitating immediate feedback and informed decision-making across a spectrum of contexts.Drawing lessons from the hypersensitive and fast-responding pressure sensing structures in the dragonfly’s neck(for stable imaging during its highly maneuverable flight),a Biomimetic Piezoresistive Pressure Sensor(BPPS)with exquisite mechanically interlocking sensing microstructures is developed.Each interlocking perceptual structure pair consists of an ox-horn-shaped and a mushroom-shaped structural unit.Through the characteristic configuration of the perceptual structure pair,the BPPS realizes a fast gradient accumulation of the contact area,thus synergistically enhancing the sensitivity and fast response capability.Remarkably,the sensitivity of the BPPS reaches 0.35 kPa^(−1),which increased by 75%compared to the 0.2 kPa^(−1) of the pressure sensors without biomimetic structures.Moreover,the BPPS also achieves rapid response/recovery times(<90/15 ms).Our BPPS finds utility in tasks such as identifying objects of different weights,monitoring human respiratory status,and tracking motion,demonstrating its potential in wearable healthcare devices,assistive technology,and intelligent soft robotics.Moreover,it possesses the advantages of high sensitivity and fast response time in practical applications.
基金National Natural Science Foundation of China under Grant No.51578463。
文摘The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.
基金supported by the National Natural Science Foundation of China (32373181)National Key Research and Development Program (2023YFD2400700)+2 种基金Science and Technology Plan Project of Fujian Province (2022L3059)High-quality Development of Marine and Fishery Industry Special Fund Project of Fujian Province (FJHYF-L-2023-5)Open Fund of Fujian Province Key Laboratory of Special Aquatic Formula Feed (TMKJZ2302)。
文摘Small RNAs(sRNAs)are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression,thereby influencing bacterial virulence and host immune responses.Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health.However,the regulatory mechanisms of sRNAs in P.plecoglossicida remain unclear.This study focused on sRNA113,previously identified as a potential regulator of the fliP gene,a key component of the lateral flagellar type III secretion system.To investigate the effects of sRNA113on P.plecoglossicida virulence,as well as its role in regulating pathogenic processes and host immune responses,mutant strains lacking this sRNA were generated and analyzed.Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P.plecoglossicida,which enhanced bacterial swarming motility,biofilm formation,and chemotaxis ability in vitro.In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P.plecoglossicida.This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system,resulting in higher bacterial loads within host tissues.This amplification of pathogenic activity intensified tissue damage,disrupted immune responses,and impaired the ability of the host to clear infection,ultimately leading to mortality.These findings underscore the critical role of sRNA113 in regulating the virulence of P.plecoglossicida and its interaction with host immune defenses.This study provides a foundation for further exploration of sRNAmediated mechanisms in bacterial pathogenesis and hostpathogen interactions,contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens.
基金supported by the Science Center for Gas Turbine Project,China(No.P2022-C-II-001-001)the National Science and Technology Major Project,China and the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.CX2022045).
文摘Flutter and forced response, as two main branches of aeroelasticity, can lead to high-cycle fatigue failure of turbomachinery blades. Efficiently and accurately assessing aeroelastic performance of turbomachinery blades is essential in the routine design. In this work, the Time Collocation Method (TCM) which uses the cubic B-spline to approximate flow variables is first thoroughly studied and then combined with the moving grid technique to analyze aeroelastic flow fields. To showcase its advantage over the Harmonic Balance (HB) method which uses a truncated Fourier series to approximately represent flow variables, a matrix analysis of the one-dimensional advection equation is first performed. The results of stability analysis are verified by two test cases: the Durham linear oscillating turbine cascade and a two-blade-row transonic compressor. The vibration of the blade of the first case is driven by a motor while the excitation force of the second case comes from blade row interaction. The results show that the time collocation method has a faster convergence rate and is more stable than the harmonic balance method, especially for cases with a large maximum grid reduced frequency. More importantly, the time collocation method is capable of accurately predicting aeroelastic performance of turbomachinery blades.
基金supported by the National Key Research and Development of China(Grant No.2022YFB4601901)the National Natural Science Foundation of China(Grant No.12122202)。
文摘The use of ultra-high molecular weight polyethylene(UHMWPE)composite in the design of lightweight protective equipment,has gained a lot of interest.However,there is an urgent need to understand the ballistic response mechanism and theoretical prediction model of performance.This paper explores the ballistic response mechanism of UHMWPE composite through experimental and simulation analyses.Then,a resistance-driven modeling method was proposed to establish a theoretical model for predicting the bulletproof performance.The ballistic response mechanism of UHMWPE composite encompassed three fundamental modes:local response,structural response,and coupled response.The occurrence ratio of these fundamental response modes during impact was dependent on the projectile velocity and laminate thickness.The bulletproof performance of laminate under different response modes was assessed based on the penetration depth of the projectile,the bulging height on the rear face of the laminate,the thickness of remaining sub-laminate,and residual velocity of the projectile.The absolute deviations of bulletproof performance indicator between theoretical value and experimental value were well within 11.13%,demonstrating that the established evaluation model possessed high degree of prediction accuracy.
文摘The strongest earthquake to hit Myanmar in over a century has caused huge damage and numerous deaths since it struck the Southeast Asian country on March 28.As of April 2,the 7.9-magnitude quake had killed 2,886 people and wounded 4,639,according to official statistics.The numbers are expected to rise as rescue efforts and damage assessments continue.
