MXene-based smart contact lenses demonstrate a cutting-edge advancement in wearable ophthalmic technology,combining real-time biosensing,therapeutic capabilities,and user comfort in a single platform.These devices tak...MXene-based smart contact lenses demonstrate a cutting-edge advancement in wearable ophthalmic technology,combining real-time biosensing,therapeutic capabilities,and user comfort in a single platform.These devices take the advantage of the exceptional electrical conductivity,mechanical flexibility,and biocompatibility of two-dimensional MXenes to enable noninvasive,tear-based monitoring of key physiological markers such as intraocular pressure and glucose levels.Recent developments focus on the integration of transparent MXene films into the conventional lens materials,allowing multifunctional performance including photothermal therapy,antimicrobial and anti-inflammation protection,and dehydration resistance.These innovations offer promising strategies for ocular disease management and eye protection.In addition to their multifunctionality,improvements in MXene synthesis and device engineering have enhanced the stability,transparency,and wearability of these lenses.Despite these advances,challenges remain in long-term biostability,scalable production,and integration with wireless communication systems.This review summarizes the current progress,key challenges,and future directions of MXene-based smart contact lenses,highlighting their transformative potential in next-generation digital healthcare and ophthalmic care.展开更多
Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unco...Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.展开更多
Green transplant refers to the realization of the importance of understanding and improving the environmental footprint of transplantation through sustainable practices.This involves assessing the entire transplantati...Green transplant refers to the realization of the importance of understanding and improving the environmental footprint of transplantation through sustainable practices.This involves assessing the entire transplantation process including preoperative evaluation,donation,organ and patient transportation,surgery,postoperative recovery,and follow-up.This is a topic that has not been fully addressed yet,but its importance is being increasingly appreciated in surgery.The aim of this study was to investigate the carbon footprint associated with transplantation and propose sustainable mitigating solutions.A comprehensive review of the existing literature on transplantation was conducted and supplemented with findings from the broader fields of surgical and perioperative care,given the scarcity of available data.The analysis identified the most involved environmental factors and attempted to offer practical solutions based on current sustainability practices.Notably,no study has yet examined the carbon footprint associated with the entire transplantation procedure.Only five studies have attempted to assess the environmental impact of kidney or liver transplants,but they focused,almost explicitly,on specific steps of the process.By employing an extrapolative methodology from the broader surgical field,we determined that the primary contributors to the environmental impact of transplantation are energy,consumables and materials,anesthesia and pharmaceuticals,transportation,and water.This review offers practical solutions utilizing the 5R framework,emphasizing sustainability to ensure transplantation remains clinically and environmentally relevant.展开更多
Understanding water chemistry in karst regions is crucial for improving global water resource management and deepening our knowledge of the biogeochemical cycles shaping these sensitive environments.Despite advance-me...Understanding water chemistry in karst regions is crucial for improving global water resource management and deepening our knowledge of the biogeochemical cycles shaping these sensitive environments.Despite advance-ments in karst hydrology,significant gaps remain in long-term trends,underlying processes,and quantitative effects of environmental changes.This is especially true in areas like the Wujiang River(WJ)in China,where human activities such as reservoir construction and land use/cover changes have accelerated hydrochemical changes.We combined recent and historical monitoring data to provide a detailed analysis of the spatial and temporal characteristics,evolution,and controlling factors of major ions in WJ.These findings are important for local water management and contribute to global efforts to manage similar karst systems facing human-induced pressures.Our research shows clear seasonal differences in solute concentrations,with higher levels during the dry season.WJ’s water is rich in calcium,with Ca-HCO_(3) ion pairs being the most common.Reservoir monitor-ing stations show much higher levels of NO_(3)^(−)and SO_(4)^(2−)compared to river-type stations,likely due to longer hydraulic retention time and increased acid deposition.The study confirms the significant role of pH and water temperature in rock weathering processes.Land use/cover changes were identified as the primary drivers of solute variations(46.37%),followed by lithology(13.92%)and temperature(8.35%).Over the past two decades,in-tense carbonate weathering has been observed,especially during wet seasons.Among karstic provinces,Guizhou Province stands out with the highest ion concentrations,indicative of its extensive karst coverage and heightened weathering processes.展开更多
The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for ge...The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for geothermal resources.However,geothermal exploration within the Yuncheng Basin typically faces significant challenges due to civil and industrial noise from dense populations and industrial activities.To address these challenges,both Controlled-Source Audio-frequency Magnetotellurics(CSAMT)and radon measurements were employed in Baozigou village to investigate the geothermal structures and identify potential geothermal targets.The CSAMT method effectively delineated the structure of the subsurface hydrothermal system,identifying the reservoir as Paleogene sandstones and Ordovician and Cambrian limestones at elevations ranging from−800 m to−2500 m.In particular,two concealed normal faults(F_(a)and F_(b))were newly revealed by the combination of CSAMT and radon profiling;these previously undetected faults,which exhibit different scales and opposing dips,are likely to be responsible for controlling the convection of thermal water within the Basin’s subsurface hydrothermal system.Moreover,this study developed a preliminary conceptual geothermal model for the Fen River Depression within the Yuncheng Basin,which encompasses geothermal heat sources,cap rocks,reservoirs,and fluid pathways,providing valuable insights for future geothermal exploration.In conjunction with the 3D geological model constructed from CSAMT resistivity structures beneath Baozigou village,test drilling is recommended in the northwestern region of the Baozigou area to intersect the potentially deep fractured carbonates that may contain temperature-elevated geothermal water.This study establishes a good set of guidelines for future geothermal exploration in this region,indicating that high-permeability faults in the central segments of the Fen River Depression are promising targets.展开更多
Non-selective hunting of waterbirds poses a significant challenge in biodiversity-rich areas such as Important Bird Areas (IBAs), where protected and game species congregate. Here, we present evidence from three conse...Non-selective hunting of waterbirds poses a significant challenge in biodiversity-rich areas such as Important Bird Areas (IBAs), where protected and game species congregate. Here, we present evidence from three consecutive hunting seasons spanning autumn 2021 to spring 2024 at a Natura 2000 site in western Poland, based on analyses of hunting bag photographs, local hunting records, and standardized bird monitoring data. We recorded 1331 hunted individuals from 14 species, 43% of which are protected under national or EU legislation. Among these was the Vulnerable Common Pochard (Aythya ferina), listed on the IUCN Red List. For nearly all species, harvest rates exceeded the sustainable thresholds defined by BirdLife International. Statistical comparisons between species' environmental abundance and their representation in hunting bags indicated no selectivity in shooting, pointing to indiscriminate hunting practices. Simultaneous waterbird monitoring (2018–2024) revealed steep declines in the local waterbird community and a marked decrease in Common Crane (Grus grus) numbers, with average autumn roost counts dropping from over 2000 individuals prior to hunting to 320 during hunting seasons. Although causality cannot be directly confirmed, these patterns suggest substantial disturbance effects. Our findings demonstrate the impracticality of selective hunting in species-rich wetland refuges and highlight the systematic killing of protected species. We recommend banning waterbird hunting in IBAs and implementing mandatory bird identification training and certification for hunters to reduce unintended impacts on vulnerable species.展开更多
Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and th...Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.展开更多
Chronic,non-healing wounds represent a significant challenge for healthcare systems worldwide,often requiring significant human and financial resources.Chronic wounds arise from the complex interplay of underlying com...Chronic,non-healing wounds represent a significant challenge for healthcare systems worldwide,often requiring significant human and financial resources.Chronic wounds arise from the complex interplay of underlying comorbidities,such as diabetes or vascular diseases,lifestyle factors,and genetic risk profiles which may predispose extremities to local ischemia.Injuries are further exacerbated by bacterial colonization and the formation of biofilms.Infection,consequently,perpetuates a chronic inflammatory microenvironment,preventing the progression and completion of normal wound healing.The current standard of care(SOC)for chronic wounds involves surgical debridement along with localized wound irrigation,which requires inpatient care under general anesthesia.This could be followed by,if necessary,defect coverage via a reconstructive ladder utilizing wound debridement along with skin graft,local,or free flap techniques once the wound conditions are stabilized and adequate blood supply is restored.To promote physiological wound healing,a variety of approaches have been subjected to translational research.Beyond conventional wound healing drugs and devices that currently supplement treatments,cellular and immunotherapies have emerged as promising therapeutics that can behave as tailored therapies with cell-or molecule-specific wound healing properties.However,in contrast to the clinical omnipresence of chronic wound healing disorders,there remains a shortage of studies condensing the current body of evidence on cellular therapies and immunotherapies for chronic wounds.This review provides a comprehensive exploration of current therapies,experimental approaches,and translational studies,offering insights into their efficacy and limitations.Ultimately,we hope this line of research may serve as an evidence-based foundation to guide further experimental and translational approaches and optimize patient care long-term.展开更多
BACKGROUND In 2017,our institution implemented a high efficiency(HE)pathway for lower limb orthopedic surgery.The employed strategy included patient selection,surgical instrument standardization,preoperative surgical ...BACKGROUND In 2017,our institution implemented a high efficiency(HE)pathway for lower limb orthopedic surgery.The employed strategy included patient selection,surgical instrument standardization,preoperative surgical nerve blocks,avoidance of general anesthesia and bypassing phase one recovery.We conducted a historic cohort study whose primary outcome was the postoperative recovery time between the HE and traditional(T)pathway.AIM To determine whether the implementation of a HE pathway was correlated with a reduction in postoperative recovery time.METHODS Patients who had unilateral elective lower limb orthopedic procedures through the T and HE pathway were screened between 2017 to 2019.Patients were at least 18 years old,and American Society of Anesthesiologists(ASA)Physical Status I to III without major systemic comorbidities were included.Propensity score was generated using multivariable regression taking age,body mass index,sex,ASA class and surgical type as covariates using nearest neighbour methods between the two pathways.Mann Whitney U test were used to analyzed total postoperative time.RESULTS There was an associated reduction in total postoperative recovery time of 63 minutes(95%CI:-69 to-57)in the HE group.The operating room time and total length of stay also had an associated decrease of 20 minutes(95%CI:-23 to-17)and 84 minutes(95%CI:-92 to-75)respectively.CONCLUSION Utilizing multifaceted strategies to improve perioperative efficiency was associated with a reduction in the postoperative recovery time in our retrospective study.This model can be a potential strategy to deal with surgical backlog in the face of ongoing human resource challenges.展开更多
The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pr...The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pressure transient and rate transient data.The initial flowback involves producing back the fracturing fuid after hydraulic fracturing,while the second flowback involves producing back the preloading fluid injected into the parent wells before fracturing of child wells.The main objective of this research is to compare the initial and second flowback data to capture the changes in fracture volume after production and preload processes.Such a comparison is useful for evaluating well performance and optimizing frac-turing operations.We construct rate-normalized pressure(RNP)versus material balance time(MBT)diagnostic plots using both initial and second flowback data(FB;and FBs,respectively)of six multi-fractured horizontal wells completed in Niobrara and Codell formations in DJ Basin.In general,the slope of RNP plot during the FB,period is higher than that during the FB;period,indicating a potential loss of fracture volume from the FB;to the FB,period.We estimate the changes in effective fracture volume(Ver)by analyzing the changes in the RNP slope and total compressibility between these two flowback periods.Ver during FB,is in general 3%-45%lower than that during FB:.We also compare the drive mechanisms for the two flowback periods by calculating the compaction-drive index(CDI),hydrocarbon-drive index(HDI),and water-drive index(WDI).The dominant drive mechanism during both flowback periods is CDI,but its contribution is reduced by 16%in the FB,period.This drop is generally compensated by a relatively higher HDI during this period.The loss of effective fracture volume might be attributed to the pressure depletion in fractures,which occurs during the production period and can extend 800 days.展开更多
Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face...Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.展开更多
Patients in intensive care units(ICUs)require rapid critical decision making.Modern ICUs are data rich,where information streams from diverse sources.Machine learning(ML)and neural networks(NN)can leverage the rich da...Patients in intensive care units(ICUs)require rapid critical decision making.Modern ICUs are data rich,where information streams from diverse sources.Machine learning(ML)and neural networks(NN)can leverage the rich data for prognostication and clinical care.They can handle complex nonlinear relation-ships in medical data and have advantages over traditional predictive methods.A number of models are used:(1)Feedforward networks;and(2)Recurrent NN and convolutional NN to predict key outcomes such as mortality,length of stay in the ICU and the likelihood of complications.Current NN models exist in silos;their integration into clinical workflow requires greater transparency on data that are analyzed.Most models that are accurate enough for use in clinical care operate as‘black-boxes’in which the logic behind their decision making is opaque.Advan-ces have occurred to see through the opacity and peer into the processing of the black-box.In the near future ML is positioned to help in clinical decision making far beyond what is currently possible.Transparency is the first step toward vali-dation which is followed by clinical trust and adoption.In summary,NNs have the transformative ability to enhance predictive accuracy and improve patient management in ICUs.The concept should soon be turning into reality.展开更多
Unmanned Aerial Vehicles(UAVs)integrated with Wireless Sensor Networks(WSNs)present a transformative approach to environmental monitoring by enabling real-time,low power,wide-area,and high-resolution data collection.T...Unmanned Aerial Vehicles(UAVs)integrated with Wireless Sensor Networks(WSNs)present a transformative approach to environmental monitoring by enabling real-time,low power,wide-area,and high-resolution data collection.This paper proposes a UAV-based WSN framework designed for efficient ecological data acquisition,including parameters such as temperature,humidity,various gases,detection of motion of a material,and safety features.The system leverages UAVs for dynamic deployment and data retrieval from distributed sensor nodes in remote or inaccessible areas,reducing the reliance on fixed infrastructure.Long Range Communication(LoRa)technology is also integrated with a WSN to enhance network coverage and adaptability issues.The proposed system covers vast areas through LoRa communication ensuring minimal energy consumption and cost-effective sensing capabilities.Field tests and simulation findings show how well the system captures spatiotemporal environmental fluctuations,making it an invaluable tool for monitoring climate change,ecological research,and disaster response.展开更多
BACKGROUND People living with human immunodeficiency virus(HIV)are aging as a result the benefits of combination antiretroviral therapy.AIM To provide descriptions of eligible existing studies on demographics,methodol...BACKGROUND People living with human immunodeficiency virus(HIV)are aging as a result the benefits of combination antiretroviral therapy.AIM To provide descriptions of eligible existing studies on demographics,methodologies,and outcome measures related to health-related quality of life(HRQoL)in the context of HIV and aging.METHODS The MEDLINE,CINAHL,Scopus,and PsycINFO databases were systematically searched using the terms HIV,age,and HRQoL to find studies published between January 1995 and June 2022.Key variables of the eligible studies were identified and categorized into demographics(e.g.,study sites,study year),methodologies(e.g.,use of conceptual frameworks,measures used),and outcome measures[e.g.,HRQoL,quality of life(QoL)].The PRISMA 2009 checklist was followed.RESULTS A total of 68 published studies involving 53504 participants were included.The majority of the studies(55.88%)were conducted in North America,with relatively few studies conducted in Africa.The median age of participants was 51.0 years(IQR=11.0).Over one-third(32.56%)of all participants were older people living with HIV aged 50 years and older Four studies included only older female participants,and six studies included only men who have sex with men.Outcome mea-sures were assessed as HRQoL(26.47%)or QoL(36.76%).Overall,data from African studies,older women living with HIV,socioeconomic status(e.g.,employment,income,education),sexual behavioral risks,theoretical frameworks used,and follow-up studies were limited.CONCLUSION This narrative review highlights imbalances and gaps in research on HRQoL in the context of HIV and aging,providing direction for future studies in this area.展开更多
This paper presents a fully integrated platform that leverages hardware,software,and specially formulated O/W emulsions to provide localized mechanical stimuli for manipulating cellular behaviors.The system comprises ...This paper presents a fully integrated platform that leverages hardware,software,and specially formulated O/W emulsions to provide localized mechanical stimuli for manipulating cellular behaviors.The system comprises a hexapole magnetic tweezer device,position-based current calculation software,and biocompatible micro-robots embedded with magnetic microbeads for vibration-driven force generation.High-permeability materials in the tweezer tips,combined with fast-response current regulators,enable rapid and precise force control,ensuring uniform and continuous mechanical stimuli in the pico-newton range.Closed-loop control algorithms automatically adjust coil currents based on the micro-robot’s position,thereby compensating for potential hysteresis and optimizing system stability.Experimental results demonstrate stable operation at frequencies up to 4 Hz,with a theoretical possibility of extending to 8 Hz under a 2 A current,delivering mean forces around 20 pN at 1 Hz with a 57μm emulsion.Additionally,the platform allows fine-tuning of forces by altering emulsion size or bead concentrations,thereby providing researchers with a versatile approach to study apoptosis,proliferation,and the other mechanotransduction pathways.The biodegradable and cell-friendly emulsion serves as a protective membrane for the magnetic microbeads while effectively mimicking the mechanical properties of living cells.By bridging the gap between precise motion control and continuous vibrational force application,this novel platform offers a promising tool for advancing targeted cellular studies,fostering insights into tissue engineering,and improving cancer therapies.展开更多
The complex non-equilibrium solidification effects of the laser powder bed fusion(LPBF)combined with the high solubility of rare-earth(RE)elements,provide a new advanced powder metallurgy process for Mg RE alloys with...The complex non-equilibrium solidification effects of the laser powder bed fusion(LPBF)combined with the high solubility of rare-earth(RE)elements,provide a new advanced powder metallurgy process for Mg RE alloys with outstanding mechanical performances.However,its creep mechanism has not been revealed yet.The present study systematically investigates and evaluates the high-temperature creep mechanism of LPBFed WE43 alloy under varying temperatures and applied stress conditions.In addition,it thoroughly elucidates the interactions and evolution mechanisms between precipitates and disloca-tions during the creep process.Subject to residual stresses and thermal cycling,theβphase is formed in the form of“precipitation chains”(PCs)within the grains.The metastable phasesβ″,β′,andβ_(1) in-situ precipitate between the PCs.The creep resistance of the(LPBFed)WE43 alloy is governed by the evolution of precipitates and their interactions with dislocations during the creep.Under creep condi-tions at 200℃,a large number of<c+a>anddislocations undergo climb and cross-slip behaviors within the grains.During the climb and cross-slip of dislocations,the Orowan strengthening effect ofβ″,the cutting mechanisms ofβ′andβ_(1) phases relative to dislocations,and the dislocation barriers formed by theβphase arrays collectively impart excellent creep resistance to the WE43 alloy.As creep time progresses,dislocations accumulate within the grains,and theβandβ_(1) phases promote the forma-tion of subgrain boundaries,further triggering discontinuous dynamic recrystallization behaviors during the creep process.Furthermore,influenced by the directional diffusion of elements,precipitates dynami-cally form around the grain boundaries of recrystallized grains,thereby enhancing the resistance to grain boundary sliding.When the creep temperature increases to 250℃ or 300℃,a large number of<c+a>dislocations,accompanied by the dissolution of metastable phases and elemental re-diffusion,transform during the creep process into stacking faults(SFs).SFs not only exhibit high thermal stability but also act as effective dislocation barriers at high temperatures through lattice mismatch mechanisms.However,under high-temperature conditions,thermal activation leads to the dissolution of unstable metastable phases,promoting rapid coarsening and transformation of precipitates into various morphologies ofβphases,thereby causing a catastrophic decline in creep performance.At the same time,high tempera-tures further exacerbate elemental diffusion,resulting in precipitate-free zones near grain boundaries,thereby inducing crack initiation.Therefore,the creep resistance of as-deposited alloys decreases signif-icantly at higher temperatures.Building on this,the future development trends of LPBFed WE43 alloys are envisioned,where homogenizing heterostructures or introducing high aspect ratio precipitates and high-density SFs prior to creep can be regarded as a promising approach for enhancing creep resistance in LPBFed WE43 alloys.展开更多
Hydrophilicity is critical in Nafion membranes during fuel cell operation as insufficient membrane hydration leads to brittle behavior and a drop in proton conductivity.The incorporation of APTS(3-(aminopro pyl)trieth...Hydrophilicity is critical in Nafion membranes during fuel cell operation as insufficient membrane hydration leads to brittle behavior and a drop in proton conductivity.The incorporation of APTS(3-(aminopro pyl)triethoxysilane)into exfoliated graphene oxide(EGO)by covalent functionalization to be used as filler into Nafion membranes allows higher hydrophilicity for these membranes.This is associated with promoting hydroxyl,carbonyl,siloxane,silane,and amine groups within the EGO-APTS matrix.The incorporation of these materials as Fuel Cell MEAs leads to a significant reduction of the ohmic resistance measured at high frequency resistance(HFR)in electrochemical impedance spectroscopy(EIS)experiments and achieves maximum power densities of 1.33 W cm^(-2)at 60℃ at 100%RH(APTS-EGO,0.2 wt%)and1.33 W cm^(-2)at 60℃ at 70%RH(APTS-EGO,0.3 wt%),which represents an improvement of 190%compared to the commercial Nafion 212 when utilizing low humidification conditions(70%).Moreover,the as-synthesized membrane utilizes lower Nafion ionomer mass,which,in conjunction with the excellent cell performance,has the potential to decrease the cost of the membrane from 87 to 80￡/W as well as a reduction of fluorinated compounds within the membrane.展开更多
We present the discovery of TCP J07222683+6220548,a new ultracompact binary system of the AM CVn type.This system was first identified displaying aΔV=7.6 mag outburst on 2025-01-20.9416 UTC by the New Milky Way wide-...We present the discovery of TCP J07222683+6220548,a new ultracompact binary system of the AM CVn type.This system was first identified displaying aΔV=7.6 mag outburst on 2025-01-20.9416 UTC by the New Milky Way wide-field survey for transients and later independently detected by ASAS-SN and ZTF.The outburst peaked at V_(max)=12.45 and lasted for seven days,followed by a series of rebrightenings.No previous outbursts are found in archival data.Positive superhumps with a period of 0.032546±0.000084 day(46.87±0.12 minutes),barely detectable during the main outburst,became clearly visible during the first rebrightening that lasted from day 18 to day 24 after the initial outburst.No convincing change in the superhump period was detected.Dense time-series photometry follow-up by a pair of 0.5 m INASAN robotic telescopes,together with VSNET and AAVSO observers,was essential for identifying TCP J07222683+6220548 as an AM CVn system and triggering confirmation spectroscopy with the 2.5 m CMO SAI telescope.Some outbursting AM CVn systems lacking such detailed follow-up may remain unrecognized among the newly discovered cataclysmic variable candidates.展开更多
The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respe...The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respectively)and incoming flow velocities was experimentally investigated in a water channel.A surface scanner was implemented to quantify bed topography,and a tomographic particle image velocimetry system was used to characterize the three-dimensional wake flows.The results showed that due to the deflection of incoming flow,the velocity magnitude increased at the lateral sides of the blade,thereby producing distinctive symmetric scour holes in these regions.The normalized morphology profiles of the sedimentary bed,which were extracted along the streamwise direction at the location of the maximum erosion depth,exhibited a self-similar pattern that closely followed a sinusoidal wave profile.The level of velocity magnitude enhancement was highly correlated to the postures of the flexible blade.At a given flow velocity,the blade with lower aspect ratios exhibited less significant deformation,causing more significant near-bed velocity enhancement in the wake deflection zone and therefore leading to higher erosion volumes.Further investigation indicated that when the blade underwent slight deformation,the larger velocity enhancement close to the bed can be attributed to more significant flow deflection effects at the lateral sides of the blade and stronger flow mixing with high momentum flows away from the bed.Supported with measurements,a basic formula was established to quantify the shear stress acting on the sedimentary bed as a function of incoming flow velocity and blade aspect ratio.展开更多
A numerical model of low frequency waves is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called Weighted- Average Flux (WAF) method wi...A numerical model of low frequency waves is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called Weighted- Average Flux (WAF) method with Time-Operator- Splitting JOS) used for the treatment of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modeling wave setup. The short wave (or primary wave) energy equation is solved with a traditional Lax-Wendroff technique. A nonlinear wave theory is introduced. The model described in this paper is found to be satisfactory in modeling low frequency waves associated with incident bichromatic waves.展开更多
文摘MXene-based smart contact lenses demonstrate a cutting-edge advancement in wearable ophthalmic technology,combining real-time biosensing,therapeutic capabilities,and user comfort in a single platform.These devices take the advantage of the exceptional electrical conductivity,mechanical flexibility,and biocompatibility of two-dimensional MXenes to enable noninvasive,tear-based monitoring of key physiological markers such as intraocular pressure and glucose levels.Recent developments focus on the integration of transparent MXene films into the conventional lens materials,allowing multifunctional performance including photothermal therapy,antimicrobial and anti-inflammation protection,and dehydration resistance.These innovations offer promising strategies for ocular disease management and eye protection.In addition to their multifunctionality,improvements in MXene synthesis and device engineering have enhanced the stability,transparency,and wearability of these lenses.Despite these advances,challenges remain in long-term biostability,scalable production,and integration with wireless communication systems.This review summarizes the current progress,key challenges,and future directions of MXene-based smart contact lenses,highlighting their transformative potential in next-generation digital healthcare and ophthalmic care.
基金supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)grant LU 2347/3-1(to PL).
文摘Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.
文摘Green transplant refers to the realization of the importance of understanding and improving the environmental footprint of transplantation through sustainable practices.This involves assessing the entire transplantation process including preoperative evaluation,donation,organ and patient transportation,surgery,postoperative recovery,and follow-up.This is a topic that has not been fully addressed yet,but its importance is being increasingly appreciated in surgery.The aim of this study was to investigate the carbon footprint associated with transplantation and propose sustainable mitigating solutions.A comprehensive review of the existing literature on transplantation was conducted and supplemented with findings from the broader fields of surgical and perioperative care,given the scarcity of available data.The analysis identified the most involved environmental factors and attempted to offer practical solutions based on current sustainability practices.Notably,no study has yet examined the carbon footprint associated with the entire transplantation procedure.Only five studies have attempted to assess the environmental impact of kidney or liver transplants,but they focused,almost explicitly,on specific steps of the process.By employing an extrapolative methodology from the broader surgical field,we determined that the primary contributors to the environmental impact of transplantation are energy,consumables and materials,anesthesia and pharmaceuticals,transportation,and water.This review offers practical solutions utilizing the 5R framework,emphasizing sustainability to ensure transplantation remains clinically and environmentally relevant.
基金supported by Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515110824 and 2025A1515011839)Shenzhen Science and Technology Program(No.RCBS20231211090638066).
文摘Understanding water chemistry in karst regions is crucial for improving global water resource management and deepening our knowledge of the biogeochemical cycles shaping these sensitive environments.Despite advance-ments in karst hydrology,significant gaps remain in long-term trends,underlying processes,and quantitative effects of environmental changes.This is especially true in areas like the Wujiang River(WJ)in China,where human activities such as reservoir construction and land use/cover changes have accelerated hydrochemical changes.We combined recent and historical monitoring data to provide a detailed analysis of the spatial and temporal characteristics,evolution,and controlling factors of major ions in WJ.These findings are important for local water management and contribute to global efforts to manage similar karst systems facing human-induced pressures.Our research shows clear seasonal differences in solute concentrations,with higher levels during the dry season.WJ’s water is rich in calcium,with Ca-HCO_(3) ion pairs being the most common.Reservoir monitor-ing stations show much higher levels of NO_(3)^(−)and SO_(4)^(2−)compared to river-type stations,likely due to longer hydraulic retention time and increased acid deposition.The study confirms the significant role of pH and water temperature in rock weathering processes.Land use/cover changes were identified as the primary drivers of solute variations(46.37%),followed by lithology(13.92%)and temperature(8.35%).Over the past two decades,in-tense carbonate weathering has been observed,especially during wet seasons.Among karstic provinces,Guizhou Province stands out with the highest ion concentrations,indicative of its extensive karst coverage and heightened weathering processes.
基金supported by the Shanxi Province Basic Research Program(No.20210302123374)Yuncheng University Doctoral Research Initiation Fund(No.YQ-2021008)+3 种基金Excellent doctors come to Shanxi to reward scientific research projects(No.QZX-2023020)Open Fund of State Key Laboratory of Precision Geodesy(No.SKLPG2025-1-1)Joint Open Fund of the Research Platforms of School of Computer Science,China University of Geosciences,Wuhan(No.PTLH2024-B-03)Hubei Provincial Natural Science Foundation Project(No.2025AFC095).
文摘The Yuncheng Basin,located in the southern part of the Fenwei Rift,North China,exhibits obvious crust thinning(Moho uplift of 6-8 km)and shallow Curie point depth(less than 18 km)and hence holds great potential for geothermal resources.However,geothermal exploration within the Yuncheng Basin typically faces significant challenges due to civil and industrial noise from dense populations and industrial activities.To address these challenges,both Controlled-Source Audio-frequency Magnetotellurics(CSAMT)and radon measurements were employed in Baozigou village to investigate the geothermal structures and identify potential geothermal targets.The CSAMT method effectively delineated the structure of the subsurface hydrothermal system,identifying the reservoir as Paleogene sandstones and Ordovician and Cambrian limestones at elevations ranging from−800 m to−2500 m.In particular,two concealed normal faults(F_(a)and F_(b))were newly revealed by the combination of CSAMT and radon profiling;these previously undetected faults,which exhibit different scales and opposing dips,are likely to be responsible for controlling the convection of thermal water within the Basin’s subsurface hydrothermal system.Moreover,this study developed a preliminary conceptual geothermal model for the Fen River Depression within the Yuncheng Basin,which encompasses geothermal heat sources,cap rocks,reservoirs,and fluid pathways,providing valuable insights for future geothermal exploration.In conjunction with the 3D geological model constructed from CSAMT resistivity structures beneath Baozigou village,test drilling is recommended in the northwestern region of the Baozigou area to intersect the potentially deep fractured carbonates that may contain temperature-elevated geothermal water.This study establishes a good set of guidelines for future geothermal exploration in this region,indicating that high-permeability faults in the central segments of the Fen River Depression are promising targets.
文摘Non-selective hunting of waterbirds poses a significant challenge in biodiversity-rich areas such as Important Bird Areas (IBAs), where protected and game species congregate. Here, we present evidence from three consecutive hunting seasons spanning autumn 2021 to spring 2024 at a Natura 2000 site in western Poland, based on analyses of hunting bag photographs, local hunting records, and standardized bird monitoring data. We recorded 1331 hunted individuals from 14 species, 43% of which are protected under national or EU legislation. Among these was the Vulnerable Common Pochard (Aythya ferina), listed on the IUCN Red List. For nearly all species, harvest rates exceeded the sustainable thresholds defined by BirdLife International. Statistical comparisons between species' environmental abundance and their representation in hunting bags indicated no selectivity in shooting, pointing to indiscriminate hunting practices. Simultaneous waterbird monitoring (2018–2024) revealed steep declines in the local waterbird community and a marked decrease in Common Crane (Grus grus) numbers, with average autumn roost counts dropping from over 2000 individuals prior to hunting to 320 during hunting seasons. Although causality cannot be directly confirmed, these patterns suggest substantial disturbance effects. Our findings demonstrate the impracticality of selective hunting in species-rich wetland refuges and highlight the systematic killing of protected species. We recommend banning waterbird hunting in IBAs and implementing mandatory bird identification training and certification for hunters to reduce unintended impacts on vulnerable species.
基金funded by the National Key Research and Development Program of China(2024YFD1501602)the National Natural Science Foundation of China(42407437)conducted as part of the Coordinated Research Project D1.50.16,implemented by the Soil and Water Management and Crop Nutrition Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture,Department of Nuclear Sciences and Applications,Vienna,Austria。
文摘Nitrogen use efficiency in rice is lower than in upland crops,likely due to differences in soil nitrogen dynamics and crop nitrogen preferences.However,the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood.The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer.To address this poor understanding,we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops.Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil,while dissimilatory nitrate reduction to ammonium is higher in paddies,these differences being driven by flooding and lower total nitrogen content in paddies.Rice exhibited higher ammonium uptake,while upland crops had over twice the nitrate uptake.Autotrophic nitrification stimulated by p H reduced rice nitrogen uptake,while heterotrophic nitrification enhanced nitrogen uptake of upland crops.Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils,which further affected the balance of plant nitrogen uptake.These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.
基金supported by grants from the German Research Foundation (DFG)
文摘Chronic,non-healing wounds represent a significant challenge for healthcare systems worldwide,often requiring significant human and financial resources.Chronic wounds arise from the complex interplay of underlying comorbidities,such as diabetes or vascular diseases,lifestyle factors,and genetic risk profiles which may predispose extremities to local ischemia.Injuries are further exacerbated by bacterial colonization and the formation of biofilms.Infection,consequently,perpetuates a chronic inflammatory microenvironment,preventing the progression and completion of normal wound healing.The current standard of care(SOC)for chronic wounds involves surgical debridement along with localized wound irrigation,which requires inpatient care under general anesthesia.This could be followed by,if necessary,defect coverage via a reconstructive ladder utilizing wound debridement along with skin graft,local,or free flap techniques once the wound conditions are stabilized and adequate blood supply is restored.To promote physiological wound healing,a variety of approaches have been subjected to translational research.Beyond conventional wound healing drugs and devices that currently supplement treatments,cellular and immunotherapies have emerged as promising therapeutics that can behave as tailored therapies with cell-or molecule-specific wound healing properties.However,in contrast to the clinical omnipresence of chronic wound healing disorders,there remains a shortage of studies condensing the current body of evidence on cellular therapies and immunotherapies for chronic wounds.This review provides a comprehensive exploration of current therapies,experimental approaches,and translational studies,offering insights into their efficacy and limitations.Ultimately,we hope this line of research may serve as an evidence-based foundation to guide further experimental and translational approaches and optimize patient care long-term.
文摘BACKGROUND In 2017,our institution implemented a high efficiency(HE)pathway for lower limb orthopedic surgery.The employed strategy included patient selection,surgical instrument standardization,preoperative surgical nerve blocks,avoidance of general anesthesia and bypassing phase one recovery.We conducted a historic cohort study whose primary outcome was the postoperative recovery time between the HE and traditional(T)pathway.AIM To determine whether the implementation of a HE pathway was correlated with a reduction in postoperative recovery time.METHODS Patients who had unilateral elective lower limb orthopedic procedures through the T and HE pathway were screened between 2017 to 2019.Patients were at least 18 years old,and American Society of Anesthesiologists(ASA)Physical Status I to III without major systemic comorbidities were included.Propensity score was generated using multivariable regression taking age,body mass index,sex,ASA class and surgical type as covariates using nearest neighbour methods between the two pathways.Mann Whitney U test were used to analyzed total postoperative time.RESULTS There was an associated reduction in total postoperative recovery time of 63 minutes(95%CI:-69 to-57)in the HE group.The operating room time and total length of stay also had an associated decrease of 20 minutes(95%CI:-23 to-17)and 84 minutes(95%CI:-92 to-75)respectively.CONCLUSION Utilizing multifaceted strategies to improve perioperative efficiency was associated with a reduction in the postoperative recovery time in our retrospective study.This model can be a potential strategy to deal with surgical backlog in the face of ongoing human resource challenges.
文摘The fracture volume is gradually changed with the depletion of fracture pressure during the production process.However,there are few flowback models available so far that can estimate the fracture volume loss using pressure transient and rate transient data.The initial flowback involves producing back the fracturing fuid after hydraulic fracturing,while the second flowback involves producing back the preloading fluid injected into the parent wells before fracturing of child wells.The main objective of this research is to compare the initial and second flowback data to capture the changes in fracture volume after production and preload processes.Such a comparison is useful for evaluating well performance and optimizing frac-turing operations.We construct rate-normalized pressure(RNP)versus material balance time(MBT)diagnostic plots using both initial and second flowback data(FB;and FBs,respectively)of six multi-fractured horizontal wells completed in Niobrara and Codell formations in DJ Basin.In general,the slope of RNP plot during the FB,period is higher than that during the FB;period,indicating a potential loss of fracture volume from the FB;to the FB,period.We estimate the changes in effective fracture volume(Ver)by analyzing the changes in the RNP slope and total compressibility between these two flowback periods.Ver during FB,is in general 3%-45%lower than that during FB:.We also compare the drive mechanisms for the two flowback periods by calculating the compaction-drive index(CDI),hydrocarbon-drive index(HDI),and water-drive index(WDI).The dominant drive mechanism during both flowback periods is CDI,but its contribution is reduced by 16%in the FB,period.This drop is generally compensated by a relatively higher HDI during this period.The loss of effective fracture volume might be attributed to the pressure depletion in fractures,which occurs during the production period and can extend 800 days.
基金supported in part by the Natural Sciences and Engineering Research Council of Canada(NSERC)supported by the National Natural Science Foundation of China under Grant 62303403Zhejiang Provincial Natural Science Foundation of China under Grants LR25F030004 and LQ24F030022。
文摘Switched systems play an imperative role in modeling many real industrial systems with abrupt changes.Due to possible exposure to unreliable and complex physical environments,switching dynamics may simultaneously face multiple faults,including the unexpected controller disconnect,the temporary mismatch between subsystems and desired corresponding controllers,and the intermittent disordering of mode transitions.These commonly arising faults may result in severe and detrimental impacts on the reliability and convergence of the closed-loop solution,thereby bringing significant yet challenging issues to be tackled.This paper provides the first attempt to investigate the stabilization problem for a class of constrained switched linear systems with multiple faults under mode-dependent dwell time(MDT).From a set-theory perspective,we demonstrate a critical necessary and sufficient stability condition for switched systems without uncertainties.Moreover,the non-conservative stability criterion is further extended to the perturbed switched systems with rigorous proof.A switching communication network example verifies the validity of the theoretical result and demonstrates their advantages.
文摘Patients in intensive care units(ICUs)require rapid critical decision making.Modern ICUs are data rich,where information streams from diverse sources.Machine learning(ML)and neural networks(NN)can leverage the rich data for prognostication and clinical care.They can handle complex nonlinear relation-ships in medical data and have advantages over traditional predictive methods.A number of models are used:(1)Feedforward networks;and(2)Recurrent NN and convolutional NN to predict key outcomes such as mortality,length of stay in the ICU and the likelihood of complications.Current NN models exist in silos;their integration into clinical workflow requires greater transparency on data that are analyzed.Most models that are accurate enough for use in clinical care operate as‘black-boxes’in which the logic behind their decision making is opaque.Advan-ces have occurred to see through the opacity and peer into the processing of the black-box.In the near future ML is positioned to help in clinical decision making far beyond what is currently possible.Transparency is the first step toward vali-dation which is followed by clinical trust and adoption.In summary,NNs have the transformative ability to enhance predictive accuracy and improve patient management in ICUs.The concept should soon be turning into reality.
文摘Unmanned Aerial Vehicles(UAVs)integrated with Wireless Sensor Networks(WSNs)present a transformative approach to environmental monitoring by enabling real-time,low power,wide-area,and high-resolution data collection.This paper proposes a UAV-based WSN framework designed for efficient ecological data acquisition,including parameters such as temperature,humidity,various gases,detection of motion of a material,and safety features.The system leverages UAVs for dynamic deployment and data retrieval from distributed sensor nodes in remote or inaccessible areas,reducing the reliance on fixed infrastructure.Long Range Communication(LoRa)technology is also integrated with a WSN to enhance network coverage and adaptability issues.The proposed system covers vast areas through LoRa communication ensuring minimal energy consumption and cost-effective sensing capabilities.Field tests and simulation findings show how well the system captures spatiotemporal environmental fluctuations,making it an invaluable tool for monitoring climate change,ecological research,and disaster response.
文摘BACKGROUND People living with human immunodeficiency virus(HIV)are aging as a result the benefits of combination antiretroviral therapy.AIM To provide descriptions of eligible existing studies on demographics,methodologies,and outcome measures related to health-related quality of life(HRQoL)in the context of HIV and aging.METHODS The MEDLINE,CINAHL,Scopus,and PsycINFO databases were systematically searched using the terms HIV,age,and HRQoL to find studies published between January 1995 and June 2022.Key variables of the eligible studies were identified and categorized into demographics(e.g.,study sites,study year),methodologies(e.g.,use of conceptual frameworks,measures used),and outcome measures[e.g.,HRQoL,quality of life(QoL)].The PRISMA 2009 checklist was followed.RESULTS A total of 68 published studies involving 53504 participants were included.The majority of the studies(55.88%)were conducted in North America,with relatively few studies conducted in Africa.The median age of participants was 51.0 years(IQR=11.0).Over one-third(32.56%)of all participants were older people living with HIV aged 50 years and older Four studies included only older female participants,and six studies included only men who have sex with men.Outcome mea-sures were assessed as HRQoL(26.47%)or QoL(36.76%).Overall,data from African studies,older women living with HIV,socioeconomic status(e.g.,employment,income,education),sexual behavioral risks,theoretical frameworks used,and follow-up studies were limited.CONCLUSION This narrative review highlights imbalances and gaps in research on HRQoL in the context of HIV and aging,providing direction for future studies in this area.
基金part supported by JSPS KAKENHI Grant Number JP23K28396.
文摘This paper presents a fully integrated platform that leverages hardware,software,and specially formulated O/W emulsions to provide localized mechanical stimuli for manipulating cellular behaviors.The system comprises a hexapole magnetic tweezer device,position-based current calculation software,and biocompatible micro-robots embedded with magnetic microbeads for vibration-driven force generation.High-permeability materials in the tweezer tips,combined with fast-response current regulators,enable rapid and precise force control,ensuring uniform and continuous mechanical stimuli in the pico-newton range.Closed-loop control algorithms automatically adjust coil currents based on the micro-robot’s position,thereby compensating for potential hysteresis and optimizing system stability.Experimental results demonstrate stable operation at frequencies up to 4 Hz,with a theoretical possibility of extending to 8 Hz under a 2 A current,delivering mean forces around 20 pN at 1 Hz with a 57μm emulsion.Additionally,the platform allows fine-tuning of forces by altering emulsion size or bead concentrations,thereby providing researchers with a versatile approach to study apoptosis,proliferation,and the other mechanotransduction pathways.The biodegradable and cell-friendly emulsion serves as a protective membrane for the magnetic microbeads while effectively mimicking the mechanical properties of living cells.By bridging the gap between precise motion control and continuous vibrational force application,this novel platform offers a promising tool for advancing targeted cellular studies,fostering insights into tissue engineering,and improving cancer therapies.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.52201105 and 52475324)the National Key Research and Development Program of China(Nos.2023YFB3408003 and 2023YFB3308001)+4 种基金the Graduate Sci-entific Research and Innovation Foundation of Chongqing(No.CYB23018)the Innovation Support Program for Overseas Re-turnees in Chongqing(No.cx2023061)the Research Project from Chongqing Key Laboratory of High-performance Structural Additive Manufacturing(No.02090011044158)the Chengdu Key Research and Development Support Program(No.2023-YF11-00077-HZ)the Fundamental Research Foundation for the Central Universities in China(Nos.2024IAIS-QN012 and 2023CDJKYJH049)。
文摘The complex non-equilibrium solidification effects of the laser powder bed fusion(LPBF)combined with the high solubility of rare-earth(RE)elements,provide a new advanced powder metallurgy process for Mg RE alloys with outstanding mechanical performances.However,its creep mechanism has not been revealed yet.The present study systematically investigates and evaluates the high-temperature creep mechanism of LPBFed WE43 alloy under varying temperatures and applied stress conditions.In addition,it thoroughly elucidates the interactions and evolution mechanisms between precipitates and disloca-tions during the creep process.Subject to residual stresses and thermal cycling,theβphase is formed in the form of“precipitation chains”(PCs)within the grains.The metastable phasesβ″,β′,andβ_(1) in-situ precipitate between the PCs.The creep resistance of the(LPBFed)WE43 alloy is governed by the evolution of precipitates and their interactions with dislocations during the creep.Under creep condi-tions at 200℃,a large number of<c+a>anddislocations undergo climb and cross-slip behaviors within the grains.During the climb and cross-slip of dislocations,the Orowan strengthening effect ofβ″,the cutting mechanisms ofβ′andβ_(1) phases relative to dislocations,and the dislocation barriers formed by theβphase arrays collectively impart excellent creep resistance to the WE43 alloy.As creep time progresses,dislocations accumulate within the grains,and theβandβ_(1) phases promote the forma-tion of subgrain boundaries,further triggering discontinuous dynamic recrystallization behaviors during the creep process.Furthermore,influenced by the directional diffusion of elements,precipitates dynami-cally form around the grain boundaries of recrystallized grains,thereby enhancing the resistance to grain boundary sliding.When the creep temperature increases to 250℃ or 300℃,a large number of<c+a>dislocations,accompanied by the dissolution of metastable phases and elemental re-diffusion,transform during the creep process into stacking faults(SFs).SFs not only exhibit high thermal stability but also act as effective dislocation barriers at high temperatures through lattice mismatch mechanisms.However,under high-temperature conditions,thermal activation leads to the dissolution of unstable metastable phases,promoting rapid coarsening and transformation of precipitates into various morphologies ofβphases,thereby causing a catastrophic decline in creep performance.At the same time,high tempera-tures further exacerbate elemental diffusion,resulting in precipitate-free zones near grain boundaries,thereby inducing crack initiation.Therefore,the creep resistance of as-deposited alloys decreases signif-icantly at higher temperatures.Building on this,the future development trends of LPBFed WE43 alloys are envisioned,where homogenizing heterostructures or introducing high aspect ratio precipitates and high-density SFs prior to creep can be regarded as a promising approach for enhancing creep resistance in LPBFed WE43 alloys.
基金financially supported by the UK Research Council EPRSC EP/W03395X/1the Program grant SynHiSel EP/V047078/1the Hydrogen and Fuel Cells Hub(H_(2)FC SUPERGEN)EP/P024807/1。
文摘Hydrophilicity is critical in Nafion membranes during fuel cell operation as insufficient membrane hydration leads to brittle behavior and a drop in proton conductivity.The incorporation of APTS(3-(aminopro pyl)triethoxysilane)into exfoliated graphene oxide(EGO)by covalent functionalization to be used as filler into Nafion membranes allows higher hydrophilicity for these membranes.This is associated with promoting hydroxyl,carbonyl,siloxane,silane,and amine groups within the EGO-APTS matrix.The incorporation of these materials as Fuel Cell MEAs leads to a significant reduction of the ohmic resistance measured at high frequency resistance(HFR)in electrochemical impedance spectroscopy(EIS)experiments and achieves maximum power densities of 1.33 W cm^(-2)at 60℃ at 100%RH(APTS-EGO,0.2 wt%)and1.33 W cm^(-2)at 60℃ at 70%RH(APTS-EGO,0.3 wt%),which represents an improvement of 190%compared to the commercial Nafion 212 when utilizing low humidification conditions(70%).Moreover,the as-synthesized membrane utilizes lower Nafion ionomer mass,which,in conjunction with the excellent cell performance,has the potential to decrease the cost of the membrane from 87 to 80￡/W as well as a reduction of fluorinated compounds within the membrane.
基金support of the Foundation for the Development of Theoretical Physics and Mathematics BASIS(project 24-2-1-6-1)supported by the UKRI Science and Technology Facilities Council and is a collaboration between the University of Edinburgh(grant ST/N002512/1)and Queen’s University Belfast(grant ST/N002520/1)within the LSST:UK Science Consortium+4 种基金supported by the National Science Foundation under grants No.AST-1440341 and AST-2034437primarily funded to search for near earth asteroids through NASA grants NN12AR55G,80NSSC18K0284,and80NSSC18K1575partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889STFC grants ST/T000198/1 and ST/S006109/1made use of the Astrophysics Data System,funded by NASA under Cooperative Agreement 80NSSC21M00561。
文摘We present the discovery of TCP J07222683+6220548,a new ultracompact binary system of the AM CVn type.This system was first identified displaying aΔV=7.6 mag outburst on 2025-01-20.9416 UTC by the New Milky Way wide-field survey for transients and later independently detected by ASAS-SN and ZTF.The outburst peaked at V_(max)=12.45 and lasted for seven days,followed by a series of rebrightenings.No previous outbursts are found in archival data.Positive superhumps with a period of 0.032546±0.000084 day(46.87±0.12 minutes),barely detectable during the main outburst,became clearly visible during the first rebrightening that lasted from day 18 to day 24 after the initial outburst.No convincing change in the superhump period was detected.Dense time-series photometry follow-up by a pair of 0.5 m INASAN robotic telescopes,together with VSNET and AAVSO observers,was essential for identifying TCP J07222683+6220548 as an AM CVn system and triggering confirmation spectroscopy with the 2.5 m CMO SAI telescope.Some outbursting AM CVn systems lacking such detailed follow-up may remain unrecognized among the newly discovered cataclysmic variable candidates.
基金supported by the National Science Foundation under Grant No.2327916.
文摘The sedimentary bed morphology modulated by the wake flow of a wall-mounted flexible aquatic vegetation blade across various structural aspect ratios(A_(R)=l/b,where l and b are the length and width of the blade,respectively)and incoming flow velocities was experimentally investigated in a water channel.A surface scanner was implemented to quantify bed topography,and a tomographic particle image velocimetry system was used to characterize the three-dimensional wake flows.The results showed that due to the deflection of incoming flow,the velocity magnitude increased at the lateral sides of the blade,thereby producing distinctive symmetric scour holes in these regions.The normalized morphology profiles of the sedimentary bed,which were extracted along the streamwise direction at the location of the maximum erosion depth,exhibited a self-similar pattern that closely followed a sinusoidal wave profile.The level of velocity magnitude enhancement was highly correlated to the postures of the flexible blade.At a given flow velocity,the blade with lower aspect ratios exhibited less significant deformation,causing more significant near-bed velocity enhancement in the wake deflection zone and therefore leading to higher erosion volumes.Further investigation indicated that when the blade underwent slight deformation,the larger velocity enhancement close to the bed can be attributed to more significant flow deflection effects at the lateral sides of the blade and stronger flow mixing with high momentum flows away from the bed.Supported with measurements,a basic formula was established to quantify the shear stress acting on the sedimentary bed as a function of incoming flow velocity and blade aspect ratio.
基金This project was supported by the British Councilthe National Natural Science Foundation of China (Grant No.59809001 and 1 9732004)
文摘A numerical model of low frequency waves is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called Weighted- Average Flux (WAF) method with Time-Operator- Splitting JOS) used for the treatment of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modeling wave setup. The short wave (or primary wave) energy equation is solved with a traditional Lax-Wendroff technique. A nonlinear wave theory is introduced. The model described in this paper is found to be satisfactory in modeling low frequency waves associated with incident bichromatic waves.
