A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relax...A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.展开更多
With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive ...With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive maintenance.Traditional RUL prediction methods often exhibit reduced accuracy during the nonlinear aging stages of batteries and struggle to accommodate complex degradation processes.This paper introduces a novel adaptive long short-term memory(LSTM)approach that dynamically adjusts observation and prediction horizons to optimize predictive performance across various aging stages.The proposed method employs principal component analysis(PCA)for dimensionality reduction on publicly available NASA and Mendeley battery datasets to extract health indicators(HIs)and applies K-means clustering to segment the battery lifecycle into three aging stages(run-in,linear aging,and nonlinear aging),providing aging-stage-based input features for the model.Experimental results show that,in the NASA dataset,the adaptive LSTM reduces the MAE and RMSE by 0.042 and 0.043,respectively,compared to the CNN,demonstrating its effectiveness in mitigating error accumulation during the nonlinear aging stage.However,in the Mendeley dataset,the average prediction accuracy of the adaptive LSTM is slightly lower than that of the CNN and Transformer.These findings indicate that defining aging-stage-based adaptive observation and prediction horizons for LSTM can effectively enhance its performance in predicting battery RUL across the entire lifecycle.展开更多
A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This pape...A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.展开更多
Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-depositi...Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-deposition equilibrium of Co is achieved by doping Mn in the lattice of LaCo_(1-x)Mn_(x)O_(3),prolonging the lifespan in acidic conditions by 14 times.The lattice doping of Mn produces a strain that enhances the adsorption capacity of OH^(-).The self-catalysis of Mn causes the leaching Co to be deposited in the form of CoO_(2),which ensures that the long-term stability of LaCo_(1-x)Mn_(x)O_(3)is 70 h instead of 5 h for LaCoO_(3).Mn doping enhances the deprotonation of^(*)OOH→O_(2)in acidic environments.Notably,the over-potential of optimized LaCo_(1-x)Mn_(x)O_(3)is 345 mV at 10 mA cm^(-2)for acidic OER.This work presents a promising method for developing noble metal-free catalysts that enhance the acidic OER activity and stability.展开更多
Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffo...Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.展开更多
Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a num...Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a number of track parameters.One possible reason for deviations between simulated and measured results for the dynamic track behaviour is the uncertainty of the value of some track parameters used as input for the simulation.This in turn results in an uncertainty in the simulation results.In this contribution,it is proposed to use the general transformation method to assess a uncertainty band for the results.Most relevant input parameters for determining the point input mobility and the track decay rate for a ballasted track are analysed with regard to the uncertainties and for the value of each an interval is determined.Then,the general transformation method is applied to four different simulation methods,working both in the frequency and time domains.For one example track,the resulting uncertainty bands are compared to one dataset with measurements for the point mobility and the track decay rate.In addition,a sensitivity analysis is performed to determine the parameters that significantly influence the overall result.While all four simulation methods produce broad uncertainty bands for the results,none did match the measured results for the point mobility and the track decay rate over the entire frequency range considered.Besides the large influence of the uncertain pad stiffness,it turned out that the rail wear is also a significant source of uncertainty of the results.Overall,it is demonstrated that the proposed approach allows assessing the influence of uncertain input parameters in detail.展开更多
The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can ...The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.展开更多
We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a central...We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a centrally symmetric n-dimensional convex body of volume 1 is at least 2^(n)(9/8)^([n/3]).展开更多
In low-permeability geothermal reservoirs,hydro-shearing of pre-existing natural fractures plays a crucial role in improving connectivity between injection and production wells,thereby enhancing heat extraction effici...In low-permeability geothermal reservoirs,hydro-shearing of pre-existing natural fractures plays a crucial role in improving connectivity between injection and production wells,thereby enhancing heat extraction efficiency.This process increases fracture conductivity through dilation caused by injectioninduced slip;however,it also carries the risk of inducing seismic events,posing significant challenges for geothermal operations.This study employs a coupled hydro-mechanical numerical model based on the boundary element method to simulate hydro-shearing under two distinct fluid injection scenarios:(1)monotonic injection and(2)cyclic injection regulated by a traffic light system(TLS).The model assesses the effectiveness of these injection regimes in enhancing fracture conductivity while mitigating seismic hazards.Results indicate that monotonic injection frequently triggers a cascade of seismic events,disrupting pressure and stress distributions on nearby faults and resulting in complex seismic and aseismic interactions.In contrast,TLS-regulated cyclic injection,when carefully managed,promotes stable slip behavior and improves fracture conductivity.This approach proves particularly effective over extended durations during the simultaneous stimulation of two parallel faults.However,in multi-stage stimulation scenariosdwhere natural fractures are stimulated sequentiallydTLS-based cyclic injection,while more efficient at enhancing conductivity,may increase seismicity risk with prolonged application,thereby limiting its safe operational window.展开更多
In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the p...In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the production of parts and larger structures was investigated in detail.With different experimental setups in normal and microgravity,laser spots with diameters from 5 mm to 100 mm were realized to melt the regolith simulant EAC-1A and an 80%/20%mixture of TUBS-T and TUBS-M,which are used as a substitute for the actual lunar soil.In the experiments performed,the critical parameters are the size of the laser spot,the velocity of the laser spot on the surface of the powder bed,the gravity and the wettability of the powder bed by the melt.The stability of the melt pool as a function of these parameters was investigated and it was found that the formation of a stable melt pool is determined by gravity for large melt pool sizes in the range of 50 mm and by surface tension for small melt pool sizes in the range of a few mm.展开更多
Understanding the hydromechanical behavior and permeability stress sensitivity of hydraulic fractures is fundamental for geotechnical applications associated with fluid injection.This paper presents a three-dimensiona...Understanding the hydromechanical behavior and permeability stress sensitivity of hydraulic fractures is fundamental for geotechnical applications associated with fluid injection.This paper presents a three-dimensional(3D)benchmark model of a laboratory experiment on graywacke to examine the dynamic hydraulic fracturing process under a polyaxial stress state.In the numerical model,injection pressures after breakdown(postbreakdown)are varied to study the impact on fracture growth.The fluid pressure front and crack front are identified in the numerical model to analyze the dynamic relationship between fluid diffusion and fracture propagation.Following the hydraulic fracturing test,the polyaxial stresses are rotated to investigate the influence of the stress field rotation on the fracture slip behavior and permeability.The results show that fracture propagation guides fluid diffusion under a high postbreakdown injection pressure.The crack front runs ahead of the fluid pressure front.Under a low postbreakdown injection pressure,the fluid pressure front gradually reaches the crack front,and fluid diffusion is the main driving factor of fracture propagation.Under polyaxial stress conditions,fluid injection not only opens tensile fractures but also induces hydroshearing.When the polyaxial stress is rotated,the fracture slip direction of a fully extended fracture is consistent with the shear stress direction.The fracture slip direction of a partly extended fracture is influenced by the increase in shear stress.Normal stress affects the permeability evolution by changing the average mechanical aperture.Shear stress can induce shearing and sliding on the fracture plane,thereby increasing permeability.展开更多
The emissions from traditional fossil heavy-duty trucks have become a conspicuous issue worldwide.The electrical road system(ERS)can offer a viable solution for achieving zero CO_(2) emissions and has high energy effi...The emissions from traditional fossil heavy-duty trucks have become a conspicuous issue worldwide.The electrical road system(ERS)can offer a viable solution for achieving zero CO_(2) emissions and has high energy efficiency in long-distance road cargo transport.While many kinds of pantograph structures have been developed for the ERS,their corresponding pantograph-catenary dynamic characteristics under different road conditions have not been investigated.This work performs a numerical study on the dynamics of the pantograph-catenary interaction of an ERS considering different pantograph structures.First,a pantograph-catenary-truck-road model is proposed.The reduced catenary model and reduced-plate model transmission method are used to minimize model scale.Three different types of ERS pantograph structures are considered in the model.After validation,the pantograph-catenary dynamics under the influence of truck-road interactions with complex road roughness and different pantographs are studied and compared.The corresponding vibration transmission mechanism is further focused.The results show that the truck-road interaction has a significant effect on the pantograph-catenary interaction,but the pantograph with only one lower and upper armcan isolate the roll vibrationmotion transmission fromthe truck to the collector head,which has the best dynamic performance and is suggested for use in the ERS.展开更多
Steam cracking is the dominant technology for producing light olefins,which are believed to be the foundation of the chemical industry.Predictive models of the cracking process can boost production efficiency and prof...Steam cracking is the dominant technology for producing light olefins,which are believed to be the foundation of the chemical industry.Predictive models of the cracking process can boost production efficiency and profit margin.Rapid advancements in machine learning research have recently enabled data-driven solutions to usher in a new era of process modeling.Meanwhile,its practical application to steam cracking is still hindered by the trade-off between prediction accuracy and computational speed.This research presents a framework for data-driven intelligent modeling of the steam cracking process.Industrial data preparation and feature engineering techniques provide computational-ready datasets for the framework,and feedstock similarities are exploited using k-means clustering.We propose LArge-Residuals-Deletion Multivariate Adaptive Regression Spline(LARD-MARS),a modeling approach that explicitly generates output formulas and eliminates potentially outlying instances.The framework is validated further by the presentation of clustering results,the explanation of variable importance,and the testing and comparison of model performance.展开更多
The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centi...The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centimeter-level positioning with a stand-alone receiver in real-time.Although the products are available with high accuracy almost all the time,they may occasionally suffer from unexpected significant biases,which consequently degrades the positioning perfor-mance.Therefore,quality monitoring at the system-level has become more and more crucial for providing a reliable GNSS service.In this paper,we propose a method for the monitoring of realtime satellite orbit and clock products using a monitoring station network based on the Quality Control(QC)theory.The satellites with possible biases are first detected based on the outliers identified by Precise Point Positioning(PPP)in the monitoring station network.Then,the corresponding orbit and clock parameters with temporal constraints are introduced and esti-mated through the sequential Least Square(LS)estimator and the corresponding Instantaneous User Range Errors(IUREs)can be determined.A quality indicator is calculated based on the IUREs in the monitoring network and compared with a pre-defined threshold.The quality monitoring method is experimentally evaluated by monitoring the real-time orbit and clock products generated by GeoForschungsZentrum(GFZ),Potsdam.The results confirm that the problematic satellites can be detected accurately and effectively with missed detection rate 4×10^(-6) and false alarm rate 1:2×10^(-5).Considering the quality alarms,the PPP results in terms of RMS of positioning differences with respect to the International GNSS Service(IGS)weekly solution in the north,east and up directions can be improved by 12%,10%and 27%,respectively.展开更多
During the coronavirus disease 2019 (COVID-19) emergency, many hospitals were built or renovated around the world to meet the challenges posed by the rising number of infected cases. Environmental management in the ho...During the coronavirus disease 2019 (COVID-19) emergency, many hospitals were built or renovated around the world to meet the challenges posed by the rising number of infected cases. Environmental management in the hospital life cycle is vital in preventing nosocomial infection and includes many infection control procedures. In certain urgent situations, a hospital must be completed quickly, and work process approval and supervision must therefore be accelerated. Thus, many works cannot be checked in detail. This results in a lack of work liability control and increases the difficulty of ensuring the fulfillment of key infection prevention measures. This study investigates how blockchain technology can transform the work quality inspection workflow to assist in nosocomial infection control under a fast delivery requirement. A blockchain-based life-cycle environmental management framework is proposed to track the fulfillment of crucial infection control measures in the design, construction, and operation stages of hospitals. The proposed framework allows for work quality checking after the work is completed, when some work cannot be checked on time. Illustrative use cases are selected to demonstrate the capabilities of the developed solution. This study provides new insights into applying blockchain technology to address the challenge of environmental management brought by rapid delivery requirements.展开更多
The behavior of a chemical tanker(CT)in extreme waves was discussed in detail,that is,in terms of rigid body heave and pitch motions,vertical bending moments(VBMs)amidships,green water,and slamming impacts through the...The behavior of a chemical tanker(CT)in extreme waves was discussed in detail,that is,in terms of rigid body heave and pitch motions,vertical bending moments(VBMs)amidships,green water,and slamming impacts through the analysis of the experimental data from model tests.Regular wave tests conducted for two wave steepness showed that the increase in wave steepness caused the increase in the asymmetry between hogging and sagging moments and the contribution of green water on deck to the decrease in vertical wave bending moments.Random uncertainty analysis of statistical values in irregular wave tests with various seeds revealed slight experimental uncertainties on motions and VBMs and slightly higher errors in slamming pressure peaks.With the increase in forward speed,experimental uncertainty on slamming pressures at the bow increased.Breather solutions of the nonlinear Schrödinger equation applied to generate tailored extreme waves of certain critical wavelengths showed a good performance in terms of ship response,and it was further verified for the CT.展开更多
There has been a wealth of research that has examined the nature of rework in construction.Progress toward addressing the rework problem has been limited-it still plagues practice,adversely impacting a project’s perf...There has been a wealth of research that has examined the nature of rework in construction.Progress toward addressing the rework problem has been limited-it still plagues practice,adversely impacting a project’s performance.Almost all rework studies have focused on determining its proximal or root causes and therefore have overlooked the conditions that result from its manifestation.In filling this void,this paper draws upon our previous empirical studies,amongst others,to provide a much-needed theoretical framing to understand better why rework occurs,what its consequences are,and how it can be mitigated during construction.The theoretical framing we derive from our review provides construction organizations and their projects with a realization that the journey to mitigating rework begins with creating an error-mastery culture comprising authentic leadership,psychological safety,an errormanagement orientation,and resilience.We suggest that,once an error-mastery culture is established within construction organizations and their projects,they will be better positioned to realize the benefits of the techniques,tools,and technologies espoused to address rework,such as the Last Planner® and building information modeling.We also provide directions for future research and identify implications for practice so that strides toward rework mitigation in construction can be made.展开更多
The size of hysteresis loops and interior loops in pseudoelasticity were investigated with CuZnAl memory single crystal.The results show that the width of the hysteresis loop does not change significantly with tempera...The size of hysteresis loops and interior loops in pseudoelasticity were investigated with CuZnAl memory single crystal.The results show that the width of the hysteresis loop does not change significantly with temperature;while the size of the interior loops of hysteresis strongly depends on the martensitic phase fraction induced from austenit.展开更多
Seawater photoelectrolysis is showing huge potential in green energy conversion field,yet it is still a formidable challenge to develop one catalyst that can drive the electrolysis reaction stably,economically and eff...Seawater photoelectrolysis is showing huge potential in green energy conversion field,yet it is still a formidable challenge to develop one catalyst that can drive the electrolysis reaction stably,economically and efficiently.Motivated by this point,the inorganic–organic hybridization strategy is proposed to insitu construct one hierarchical electrode via concurrent electroless plating and polymerization,which assures the growth of boron-modulated nickel–cobalt oxyhydroxide nanoballs and photosensitive polyaniline nanochains on the self-supporting Ti-based foil(B-Co Ni OOH/PANI@TiO_(2)/Ti).Upon inducing photoelectric effect(PEE),the designed target electrode delivers overpotentials as low as 196 and 398 mV at 100 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively,corresponding to an activity enhancement by about 15%as compared to those without PEE.Inspiringly,when served as bifunctional electrocatalysts for overall seawater electrolysis,it can stably maintain at 200 mA cm^(-2)with negligible decay over 72 h.Further analysis reveals that the exceptional catalytic performance can be credit to the B-CoNiOOH,polyaniline(PANI)and TiO_(2)subunit coupling-induced physically and chemically synergistic catalysis effect such as admirable composition stability,photoelectric function and adhesion capability.The finding in this contribution may trigger much more broad interest to the novel hybrid catalysts consisting of photosensitive polymer and transition metal-based electrocatalysts.展开更多
This study investigates the potential of cannabidiol(CBD),one major cannabinoid of the plant Cannabis sativa,alone and in combination with a terpene-enriched extract from Humulus lupulus(“Hops 1”),on the LPS-respons...This study investigates the potential of cannabidiol(CBD),one major cannabinoid of the plant Cannabis sativa,alone and in combination with a terpene-enriched extract from Humulus lupulus(“Hops 1”),on the LPS-response of RAW 264.7 macrophages as an established in vitro model of inflammation.With the present study,we could support earlier findings of the anti-inflammatory potential of CBD,which showed a dose-dependent[0-5μM]reduction in nitric oxide and tumor necrosis factor-alpha(TNF-α)released by LPS-stimulated RAW 264.7 macrophages.Moreover,we observed an additive anti-inflammatory effect after combined CBD[5μM]and hops extract[40μg/mL]treatment.The combination of CBD and Hops 1 showed effects in LPS-stimulated RAW 264.7 cells superior to the single sub-stance treatments and akin to the control hydrocortisone.Furthermore,cellular CBD uptake increased dose-depend-ently in the presence of terpenes from Hops 1 extract.The anti-inflammatory effect of CBD and its cellular uptake positively correlated with terpene concentration,as indicated by comparison with a hemp extract containing both CBD and terpenes.These findings may contribute to the postulations for the so-called“entourage effect”between cannabinoids and terpenes and support the potential of CBD combined with phytomolecules from a non-cannabi-noid source,such as hops,for the treatment of inflammatory diseases.展开更多
基金support of her postdoctoral research at the GFZ Helmholtz Centre for Geosciences.P.Pan acknowledges the financial support of the National Natural Science Foundation of China(Grant No.52339001)H.Hofmann and Y.Ji acknowledge the financial support of the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(contract number VH-NG-1516).
文摘A multi-stage stress relaxation test was performed on a granodiorite sample to understand the deformation process prior to the macroscopic failure of brittle rocks,as well as the transient response during stress relaxation.Distributed optical fiber sensing was used to measure strains across the sample surface by helically wrapping the single-mode fiber around the cylindrical sample.Close agreement was observed between the circumferential strains obtained from the optical fibers and the extensometer.The reconstructed full-field strain contours show strain heterogeneity from the crack closure phase,and the strains in the later deformation phase are dominantly localized within the former high-strain zone.The Gini coefficient was used to quantify the degree of strain localization and shows an initial increase during the crack closure phase,a decrease during the linear elastic phase,and a subsequent increase during the post-yielding phase.This behavior corresponds to a process of initial localization from an imperfect boundary condition,homogenization,and eventual relocalization prior to the macroscopic failure of the sample.The transient strain rate decay during the stress relaxation phase was quantified using the p-value in the“Omori-like"power law function.A higher initial stress at the onset of relaxation results in a lower p-value,indicating a slower strain rate decay.As the sample approaches macroscopic failure,the lowest p-value shifts from the most damaged zone to adjacent areas,suggesting stress redistribution or crack propagation in deformed crystalline rocks under stress relaxation conditions.
基金supported by National Natural Science Foundation of China(Grant No.62403475).
文摘With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive maintenance.Traditional RUL prediction methods often exhibit reduced accuracy during the nonlinear aging stages of batteries and struggle to accommodate complex degradation processes.This paper introduces a novel adaptive long short-term memory(LSTM)approach that dynamically adjusts observation and prediction horizons to optimize predictive performance across various aging stages.The proposed method employs principal component analysis(PCA)for dimensionality reduction on publicly available NASA and Mendeley battery datasets to extract health indicators(HIs)and applies K-means clustering to segment the battery lifecycle into three aging stages(run-in,linear aging,and nonlinear aging),providing aging-stage-based input features for the model.Experimental results show that,in the NASA dataset,the adaptive LSTM reduces the MAE and RMSE by 0.042 and 0.043,respectively,compared to the CNN,demonstrating its effectiveness in mitigating error accumulation during the nonlinear aging stage.However,in the Mendeley dataset,the average prediction accuracy of the adaptive LSTM is slightly lower than that of the CNN and Transformer.These findings indicate that defining aging-stage-based adaptive observation and prediction horizons for LSTM can effectively enhance its performance in predicting battery RUL across the entire lifecycle.
文摘A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.
基金financially supported by the Shandong Provincial Natural Science Foundation(ZR2023LFG005)the National Natural Science Foundation of China(Nos.22479161,52274308 and U22B20144)the Fundamental Research Funds for the Central Universities(No.24CX03012A)。
文摘Non-precious metal cobalt-based oxide inevitably dissolves for acid oxygen evolution reaction(OER).Designing an efficient deposition channel for leaching cobalt species is a promising approach.The dissolution-deposition equilibrium of Co is achieved by doping Mn in the lattice of LaCo_(1-x)Mn_(x)O_(3),prolonging the lifespan in acidic conditions by 14 times.The lattice doping of Mn produces a strain that enhances the adsorption capacity of OH^(-).The self-catalysis of Mn causes the leaching Co to be deposited in the form of CoO_(2),which ensures that the long-term stability of LaCo_(1-x)Mn_(x)O_(3)is 70 h instead of 5 h for LaCoO_(3).Mn doping enhances the deprotonation of^(*)OOH→O_(2)in acidic environments.Notably,the over-potential of optimized LaCo_(1-x)Mn_(x)O_(3)is 345 mV at 10 mA cm^(-2)for acidic OER.This work presents a promising method for developing noble metal-free catalysts that enhance the acidic OER activity and stability.
文摘Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.
文摘Rolling noise is an important source of railway noise and depends also on the dynamic behaviour of a railway track.This is characterized by the point or transfer mobility and the track decay rate,which depend on a number of track parameters.One possible reason for deviations between simulated and measured results for the dynamic track behaviour is the uncertainty of the value of some track parameters used as input for the simulation.This in turn results in an uncertainty in the simulation results.In this contribution,it is proposed to use the general transformation method to assess a uncertainty band for the results.Most relevant input parameters for determining the point input mobility and the track decay rate for a ballasted track are analysed with regard to the uncertainties and for the value of each an interval is determined.Then,the general transformation method is applied to four different simulation methods,working both in the frequency and time domains.For one example track,the resulting uncertainty bands are compared to one dataset with measurements for the point mobility and the track decay rate.In addition,a sensitivity analysis is performed to determine the parameters that significantly influence the overall result.While all four simulation methods produce broad uncertainty bands for the results,none did match the measured results for the point mobility and the track decay rate over the entire frequency range considered.Besides the large influence of the uncertain pad stiffness,it turned out that the rail wear is also a significant source of uncertainty of the results.Overall,it is demonstrated that the proposed approach allows assessing the influence of uncertain input parameters in detail.
基金German research Foundation(DFG,grant numbers:CH2321/1–1 and SCHO1231/7–1)JH has received a scholarship from the Chinese Scholarship Council(CSC No.:201908350115).
文摘The oviduct epithelium is the initial maternal contact site for embryos after fertilization,offering the microenviron-ment before implantation.This early gestation period is particularly sensitive to stress,which can cause reduced fertil-ity and reproductive disorders in mammals.Nevertheless,the local impact of elevated stress hormones on the ovi-duct epithelium has received limited attention to date,except for a few reports on polyovulatory species like mice and pigs.In this study,we focused on the effects of chronic maternal stress on cattle,given its association with infertil-ity issues in this monoovulatory species.Bovine oviduct epithelial cells(BOEC)differentiated at the air–liquid interface(ALI)were stimulated with 250 nmol/L cortisol for 1 or 3 weeks.Subsequently,they were assessed for morphology,bioelectrical properties,and gene expression related to oviduct function,glucocorticoid pathway,cortisol metabo-lism,inflammation,and apoptosis.Results revealed adverse effects of cortisol on epithelium structure,featured by deciliation,vacuole formation,and multilayering.Additionally,cortisol exposure led to an increase in transepithelial potential difference,downregulated mRNA expression of the major glucocorticoid receptor(NR3C1),upregulated the expression of cortisol-responsive genes(FKBP5,TSC22D3),and significant downregulation of oviductal glycopro-tein 1(OVGP1)and steroid receptors PGR and ESR1.The systematic comparison to a similar experiment previously performed by us in porcine oviduct epithelial cells,indicated that bovine cultures were more susceptible to elevated cortisol levels than porcine.The distinct responses between both species are likely linked to their divergence in the cortisol-induced expression changes of HSD11B2,an enzyme controlling the cellular capacity to metabolise cortisol.These findings provide insights into the species-specific reactions and reproductive consequences triggered by maternal stress.
文摘We show that the volume of the projection bodyΠ(Z)of an n-dimensional zonotope Z with n+1 generators and of volume 1 is always exactly 2^(n).Moroever,we point out that an upper bound on the volume ofΠ(K)of a centrally symmetric n-dimensional convex body of volume 1 is at least 2^(n)(9/8)^([n/3]).
基金the financial support of the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES(Contract number VHNG-1516).
文摘In low-permeability geothermal reservoirs,hydro-shearing of pre-existing natural fractures plays a crucial role in improving connectivity between injection and production wells,thereby enhancing heat extraction efficiency.This process increases fracture conductivity through dilation caused by injectioninduced slip;however,it also carries the risk of inducing seismic events,posing significant challenges for geothermal operations.This study employs a coupled hydro-mechanical numerical model based on the boundary element method to simulate hydro-shearing under two distinct fluid injection scenarios:(1)monotonic injection and(2)cyclic injection regulated by a traffic light system(TLS).The model assesses the effectiveness of these injection regimes in enhancing fracture conductivity while mitigating seismic hazards.Results indicate that monotonic injection frequently triggers a cascade of seismic events,disrupting pressure and stress distributions on nearby faults and resulting in complex seismic and aseismic interactions.In contrast,TLS-regulated cyclic injection,when carefully managed,promotes stable slip behavior and improves fracture conductivity.This approach proves particularly effective over extended durations during the simultaneous stimulation of two parallel faults.However,in multi-stage stimulation scenariosdwhere natural fractures are stimulated sequentiallydTLS-based cyclic injection,while more efficient at enhancing conductivity,may increase seismicity risk with prolonged application,thereby limiting its safe operational window.
基金supported by 40th DLR Parabolic Flight Campaign and within the project"Powder based Additive Manufacturing at reduced Gravitation"(Grant No.FKZ:50WM2068)European Space Agency,OSIP Off-Earth Manufacturing and Construction Campaign(Grant No.4000134280/21/NL/GLC/mk)。
文摘In order to increase the sustainability of future lunar missions,techniques for in-situ resource utilization(ISRU)must be developed.In this context,the local melting of lunar dust(regolith)by laser radiation for the production of parts and larger structures was investigated in detail.With different experimental setups in normal and microgravity,laser spots with diameters from 5 mm to 100 mm were realized to melt the regolith simulant EAC-1A and an 80%/20%mixture of TUBS-T and TUBS-M,which are used as a substitute for the actual lunar soil.In the experiments performed,the critical parameters are the size of the laser spot,the velocity of the laser spot on the surface of the powder bed,the gravity and the wettability of the powder bed by the melt.The stability of the melt pool as a function of these parameters was investigated and it was found that the formation of a stable melt pool is determined by gravity for large melt pool sizes in the range of 50 mm and by surface tension for small melt pool sizes in the range of a few mm.
基金supported by the Knowledge Innovation Program of Wuhan-Basic Research (Grant No.2022010801010159)support from the Helmholtz Association's Initiative and Networking Fund for the Helmholtz Young Investigator Group ARES (Contract number VH-NG-1516)supported by the Swedish Radiation Safety Authority (Project SSM2020-2758).
文摘Understanding the hydromechanical behavior and permeability stress sensitivity of hydraulic fractures is fundamental for geotechnical applications associated with fluid injection.This paper presents a three-dimensional(3D)benchmark model of a laboratory experiment on graywacke to examine the dynamic hydraulic fracturing process under a polyaxial stress state.In the numerical model,injection pressures after breakdown(postbreakdown)are varied to study the impact on fracture growth.The fluid pressure front and crack front are identified in the numerical model to analyze the dynamic relationship between fluid diffusion and fracture propagation.Following the hydraulic fracturing test,the polyaxial stresses are rotated to investigate the influence of the stress field rotation on the fracture slip behavior and permeability.The results show that fracture propagation guides fluid diffusion under a high postbreakdown injection pressure.The crack front runs ahead of the fluid pressure front.Under a low postbreakdown injection pressure,the fluid pressure front gradually reaches the crack front,and fluid diffusion is the main driving factor of fracture propagation.Under polyaxial stress conditions,fluid injection not only opens tensile fractures but also induces hydroshearing.When the polyaxial stress is rotated,the fracture slip direction of a fully extended fracture is consistent with the shear stress direction.The fracture slip direction of a partly extended fracture is influenced by the increase in shear stress.Normal stress affects the permeability evolution by changing the average mechanical aperture.Shear stress can induce shearing and sliding on the fracture plane,thereby increasing permeability.
基金supported by the National Natural Science Foundation of China(grant number 12302048,received by author Yan Xu)Yunnan fundamental research projects(grant No.202501AT070321,received by author Yan Xu).
文摘The emissions from traditional fossil heavy-duty trucks have become a conspicuous issue worldwide.The electrical road system(ERS)can offer a viable solution for achieving zero CO_(2) emissions and has high energy efficiency in long-distance road cargo transport.While many kinds of pantograph structures have been developed for the ERS,their corresponding pantograph-catenary dynamic characteristics under different road conditions have not been investigated.This work performs a numerical study on the dynamics of the pantograph-catenary interaction of an ERS considering different pantograph structures.First,a pantograph-catenary-truck-road model is proposed.The reduced catenary model and reduced-plate model transmission method are used to minimize model scale.Three different types of ERS pantograph structures are considered in the model.After validation,the pantograph-catenary dynamics under the influence of truck-road interactions with complex road roughness and different pantographs are studied and compared.The corresponding vibration transmission mechanism is further focused.The results show that the truck-road interaction has a significant effect on the pantograph-catenary interaction,but the pantograph with only one lower and upper armcan isolate the roll vibrationmotion transmission fromthe truck to the collector head,which has the best dynamic performance and is suggested for use in the ERS.
基金supported by the National Key Research and Development Program of China(2021 YFB 4000500,2021 YFB 4000501,and 2021 YFB 4000502)。
文摘Steam cracking is the dominant technology for producing light olefins,which are believed to be the foundation of the chemical industry.Predictive models of the cracking process can boost production efficiency and profit margin.Rapid advancements in machine learning research have recently enabled data-driven solutions to usher in a new era of process modeling.Meanwhile,its practical application to steam cracking is still hindered by the trade-off between prediction accuracy and computational speed.This research presents a framework for data-driven intelligent modeling of the steam cracking process.Industrial data preparation and feature engineering techniques provide computational-ready datasets for the framework,and feedstock similarities are exploited using k-means clustering.We propose LArge-Residuals-Deletion Multivariate Adaptive Regression Spline(LARD-MARS),a modeling approach that explicitly generates output formulas and eliminates potentially outlying instances.The framework is validated further by the presentation of clustering results,the explanation of variable importance,and the testing and comparison of model performance.
基金funded by the National Natural Science Foundation of China(42030109).
文摘The Real-Time Global Navigation Satellite System(GNSS)Precise Positioning Service(RTPPS)is recognized as the most promising system by providing precise satellite orbit and clock correc-tions for users to achieve centimeter-level positioning with a stand-alone receiver in real-time.Although the products are available with high accuracy almost all the time,they may occasionally suffer from unexpected significant biases,which consequently degrades the positioning perfor-mance.Therefore,quality monitoring at the system-level has become more and more crucial for providing a reliable GNSS service.In this paper,we propose a method for the monitoring of realtime satellite orbit and clock products using a monitoring station network based on the Quality Control(QC)theory.The satellites with possible biases are first detected based on the outliers identified by Precise Point Positioning(PPP)in the monitoring station network.Then,the corresponding orbit and clock parameters with temporal constraints are introduced and esti-mated through the sequential Least Square(LS)estimator and the corresponding Instantaneous User Range Errors(IUREs)can be determined.A quality indicator is calculated based on the IUREs in the monitoring network and compared with a pre-defined threshold.The quality monitoring method is experimentally evaluated by monitoring the real-time orbit and clock products generated by GeoForschungsZentrum(GFZ),Potsdam.The results confirm that the problematic satellites can be detected accurately and effectively with missed detection rate 4×10^(-6) and false alarm rate 1:2×10^(-5).Considering the quality alarms,the PPP results in terms of RMS of positioning differences with respect to the International GNSS Service(IGS)weekly solution in the north,east and up directions can be improved by 12%,10%and 27%,respectively.
基金supported by the National Natural Science Foundation of China(71732001,51878311,72271106,U21A20151,and 71821001)Engineering Fronts Project(2021-HYZD-5-13)+1 种基金Major Science&Technology Project of Hubei(2020ACA006)China Scholarship Council(202006160115).
文摘During the coronavirus disease 2019 (COVID-19) emergency, many hospitals were built or renovated around the world to meet the challenges posed by the rising number of infected cases. Environmental management in the hospital life cycle is vital in preventing nosocomial infection and includes many infection control procedures. In certain urgent situations, a hospital must be completed quickly, and work process approval and supervision must therefore be accelerated. Thus, many works cannot be checked in detail. This results in a lack of work liability control and increases the difficulty of ensuring the fulfillment of key infection prevention measures. This study investigates how blockchain technology can transform the work quality inspection workflow to assist in nosocomial infection control under a fast delivery requirement. A blockchain-based life-cycle environmental management framework is proposed to track the fulfillment of crucial infection control measures in the design, construction, and operation stages of hospitals. The proposed framework allows for work quality checking after the work is completed, when some work cannot be checked on time. Illustrative use cases are selected to demonstrate the capabilities of the developed solution. This study provides new insights into applying blockchain technology to address the challenge of environmental management brought by rapid delivery requirements.
文摘The behavior of a chemical tanker(CT)in extreme waves was discussed in detail,that is,in terms of rigid body heave and pitch motions,vertical bending moments(VBMs)amidships,green water,and slamming impacts through the analysis of the experimental data from model tests.Regular wave tests conducted for two wave steepness showed that the increase in wave steepness caused the increase in the asymmetry between hogging and sagging moments and the contribution of green water on deck to the decrease in vertical wave bending moments.Random uncertainty analysis of statistical values in irregular wave tests with various seeds revealed slight experimental uncertainties on motions and VBMs and slightly higher errors in slamming pressure peaks.With the increase in forward speed,experimental uncertainty on slamming pressures at the bow increased.Breather solutions of the nonlinear Schrödinger equation applied to generate tailored extreme waves of certain critical wavelengths showed a good performance in terms of ship response,and it was further verified for the CT.
基金financial support of the Australian Research Council (DP210101281)。
文摘There has been a wealth of research that has examined the nature of rework in construction.Progress toward addressing the rework problem has been limited-it still plagues practice,adversely impacting a project’s performance.Almost all rework studies have focused on determining its proximal or root causes and therefore have overlooked the conditions that result from its manifestation.In filling this void,this paper draws upon our previous empirical studies,amongst others,to provide a much-needed theoretical framing to understand better why rework occurs,what its consequences are,and how it can be mitigated during construction.The theoretical framing we derive from our review provides construction organizations and their projects with a realization that the journey to mitigating rework begins with creating an error-mastery culture comprising authentic leadership,psychological safety,an errormanagement orientation,and resilience.We suggest that,once an error-mastery culture is established within construction organizations and their projects,they will be better positioned to realize the benefits of the techniques,tools,and technologies espoused to address rework,such as the Last Planner® and building information modeling.We also provide directions for future research and identify implications for practice so that strides toward rework mitigation in construction can be made.
文摘The size of hysteresis loops and interior loops in pseudoelasticity were investigated with CuZnAl memory single crystal.The results show that the width of the hysteresis loop does not change significantly with temperature;while the size of the interior loops of hysteresis strongly depends on the martensitic phase fraction induced from austenit.
基金supported by the National Natural Science Foundation of China(22109098)the Shanghai Sailing Program(20YF1432300)+4 种基金the Shanghai Engineering Research Center for Food Rapid Detection(19DZ2251300)the Natural Science Foundation of Jiangsu Province(BK20210735)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(21KJB430043)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Projectthe Suzhou Key Laboratory of Functional Nano&Soft Materials。
文摘Seawater photoelectrolysis is showing huge potential in green energy conversion field,yet it is still a formidable challenge to develop one catalyst that can drive the electrolysis reaction stably,economically and efficiently.Motivated by this point,the inorganic–organic hybridization strategy is proposed to insitu construct one hierarchical electrode via concurrent electroless plating and polymerization,which assures the growth of boron-modulated nickel–cobalt oxyhydroxide nanoballs and photosensitive polyaniline nanochains on the self-supporting Ti-based foil(B-Co Ni OOH/PANI@TiO_(2)/Ti).Upon inducing photoelectric effect(PEE),the designed target electrode delivers overpotentials as low as 196 and 398 mV at 100 mA cm^(-2)for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively,corresponding to an activity enhancement by about 15%as compared to those without PEE.Inspiringly,when served as bifunctional electrocatalysts for overall seawater electrolysis,it can stably maintain at 200 mA cm^(-2)with negligible decay over 72 h.Further analysis reveals that the exceptional catalytic performance can be credit to the B-CoNiOOH,polyaniline(PANI)and TiO_(2)subunit coupling-induced physically and chemically synergistic catalysis effect such as admirable composition stability,photoelectric function and adhesion capability.The finding in this contribution may trigger much more broad interest to the novel hybrid catalysts consisting of photosensitive polymer and transition metal-based electrocatalysts.
文摘This study investigates the potential of cannabidiol(CBD),one major cannabinoid of the plant Cannabis sativa,alone and in combination with a terpene-enriched extract from Humulus lupulus(“Hops 1”),on the LPS-response of RAW 264.7 macrophages as an established in vitro model of inflammation.With the present study,we could support earlier findings of the anti-inflammatory potential of CBD,which showed a dose-dependent[0-5μM]reduction in nitric oxide and tumor necrosis factor-alpha(TNF-α)released by LPS-stimulated RAW 264.7 macrophages.Moreover,we observed an additive anti-inflammatory effect after combined CBD[5μM]and hops extract[40μg/mL]treatment.The combination of CBD and Hops 1 showed effects in LPS-stimulated RAW 264.7 cells superior to the single sub-stance treatments and akin to the control hydrocortisone.Furthermore,cellular CBD uptake increased dose-depend-ently in the presence of terpenes from Hops 1 extract.The anti-inflammatory effect of CBD and its cellular uptake positively correlated with terpene concentration,as indicated by comparison with a hemp extract containing both CBD and terpenes.These findings may contribute to the postulations for the so-called“entourage effect”between cannabinoids and terpenes and support the potential of CBD combined with phytomolecules from a non-cannabi-noid source,such as hops,for the treatment of inflammatory diseases.
