This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,a...This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,and samarium was prepared by dissolving their pure mixed oxide(reclaimed from spent Ni-MH batteries)in a diluted HCl solution.Key extractants,including bis(2,4,4-trimethylpentyl)phosphinic acid(Cyanex 272),Cyanex 572,trialkylphosphine oxide(Cyanex 923),and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC 88A),along with tributyl phosphate(TBP)as a phase modifier,were utilized to form organic systems.The extraction behavior and separability of these systems at various pH levels as well as their extraction mechanisms were investigated.The results demonstrated a direct relationship between the extraction trend and the experimental pH value,with enhanced selectivity when TBP was added.Notably,Nd and Pr exhibited similar extraction behaviors,with minor deviations from Ce,making their separation difficult to achieve.Sm extraction followed a distinct trend,allowing for its separation from other elements at pH≤2.In contrast,La exhibited a low affinity for coordination with extractants when pH was≤3.5,facilitating the separation of other elements from La,which could then be isolated in the raffinate.Among the studied organic systems,combinations of Cyanex 572 and PC 88A with TBP demonstrated superior performance in element separation.Optimum separation factors were calculated withβ_(Ce/La)=12,βNd/La=87,β_(Pr/La)=127,andβ_(Sm/La)=3191 for the former,andβ_(Sm/Ce)=54,β_(Sm/Nd)=20,andβ_(Sm/Pr)=14 for the latter.These findings provide valuable insights for selecting extraction systems and designing experiments for the effective solvent extraction separation of light REEs from their mixture.展开更多
1.Background In the chemical industry,process plants-commonly referred to as plantwide systems-typically consist of many process units(unit operations).Driven by the considerable economic efficiency offered by complex...1.Background In the chemical industry,process plants-commonly referred to as plantwide systems-typically consist of many process units(unit operations).Driven by the considerable economic efficiency offered by complex and interactive process designs,modern plantwide systems are becoming increasingly sophisticated.The operation of these processes is typically characterized by the complexity of individual units(subsystems)and the intricate interactions between geographically distributed units through networks of material and energy flows,as well as control loops[1].展开更多
The effectiveness of industrial character recognition on cast steel is often compromised by factors such as corrosion,surface defects,and low contrast,which hinder the extraction of reliable visual information.The pro...The effectiveness of industrial character recognition on cast steel is often compromised by factors such as corrosion,surface defects,and low contrast,which hinder the extraction of reliable visual information.The problem is further compounded by the scarcity of large-scale annotated datasets and complex noise patterns in real-world factory environments.This makes conventional OCR techniques and standard deep learning models unreliable.To address these limitations,this study proposes a unified framework that integrates adaptive image preprocessing with collaborative reasoning among LLMs.A Biorthogonal 4.4(bior4.4)wavelet transform is adaptively tuned using DE to enhance character edge clarity,suppress background noise,and retain morphological structure,thereby improving input quality for subsequent recognition.A structured three-round debate mechanism is further introduced within a multi-agent architecture,employing GPT-4o and Gemini-2.0-flash as role-specialized agents to perform complementary inference and achieve consensus.The proposed system is evaluated on a proprietary dataset of 48 high-resolution images collected under diverse industrial conditions.Experimental results show that the combination of DE-based enhancement and multi-agent collaboration consistently outperforms traditional baselines and ablated models,achieving an F1-score of 94.93%and an LCS accuracy of 93.30%.These results demonstrate the effectiveness of integrating signal processing with multi-agent LLM reasoning to achieve robust and interpretable OCR in visually complex and data-scarce industrial environments.展开更多
Polymer gears are increasingly replacing metal gears in applications with low to medium torque.Traditionally,polymer gears have been manufactured using injection molding,but additive manufacturing(AM)is becoming incre...Polymer gears are increasingly replacing metal gears in applications with low to medium torque.Traditionally,polymer gears have been manufactured using injection molding,but additive manufacturing(AM)is becoming increasingly common.Among the different types of polymer gears,nylon gears are particularly popular.However,there is currently very limited understanding of the wear resistance of nylon gears and of the impact of the manufacturing method on gear wear performance.The aims of this work are(a)to study the wear process of nylon gears made using the conventional injection molding method and two popularly used AM methods,namely,fused deposition modeling and selective laser sintering,(b)to compare and understand the wear performance by monitoring the evolution of the gear surfaces of the teeth,and(c)to study the effect of wear on the gear dynamics by analyzing gearbox vibration signals.This article presents experimental work,data analysis of the wear processes using molding and image analysis techniques,as well as the vibration data collected during gear wear tests.It also provides key results and further insights into the wear performance of the tested nylon gears.The information gained in this study is useful for better understanding the degradation process of additively manufactured nylon gears.展开更多
Manufacturers must identify and classify various defects in automotive sealing rings to ensure product quality.Deep learning algorithms show promise in this field,but challenges remain,especially in detecting small-sc...Manufacturers must identify and classify various defects in automotive sealing rings to ensure product quality.Deep learning algorithms show promise in this field,but challenges remain,especially in detecting small-scale defects under harsh industrial conditions with multimodal data.This paper proposes an enhanced version of You Only Look Once(YOLO)v8 for improved defect detection in automotive sealing rings.We introduce the Multi-scale Adaptive Feature Extraction(MAFE)module,which integrates Deformable ConvolutionalNetwork(DCN)and Spaceto-Depth(SPD)operations.This module effectively captures long-range dependencies,enhances spatial aggregation,and minimizes information loss of small objects during feature extraction.Furthermore,we introduce the Blur-Aware Wasserstein Distance(BAWD)loss function,which improves regression accuracy and detection capabilities for small object anchor boxes,particularly in scenarios involving defocus blur.Additionally,we have constructed a high-quality dataset of automotive sealing ring defects,providing a valuable resource for evaluating defect detection methods.Experimental results demonstrate our method’s high performance,achieving 98.30% precision,96.62% recall,and an inference speed of 20.3 ms.展开更多
Fe-doped CuCrO_(2) catalyst CuCr_(1-x)Fe_xO_(2) series were prepared by the sol-gel method with different Fe contents.The structure and properties of the catalysts were investigated by XRD(X-ray diffraction),SEM(scann...Fe-doped CuCrO_(2) catalyst CuCr_(1-x)Fe_xO_(2) series were prepared by the sol-gel method with different Fe contents.The structure and properties of the catalysts were investigated by XRD(X-ray diffraction),SEM(scanning electron microscope),and XPS(X-ray photoelectron spectroscopy)and the purification effect on NO_(x) and PM was measured through simulated emission experiments.The results indicate that CuCrO_(2) catalyst has good catalytic activity,the maximum NO_(x) conversion rate can be up to 28.15%,and the ignition temperature of PM can be reduced to 285℃.When the molecular ratio of Cr:Fe=9:1,the catalyst can achieve better catalytic effect,the maximum NO_(x) conversion rate will be up to 30.25%and the PM ignition temperature can be reduced to 280℃.In addition,the catalytic activity of catalyst supported on different carriers was also studied.The results show that catalyst on SiC foam ceramic carrier has better catalytic activity than that on cordierite honeycomb ceramic carrier.The maximum NO_(x) conversion of CuCrO_(2) and CuCr_(0.9)Fe_(0.1)O_(2) can be increased by 0.72%and 1.33%respectively,and the PM ignition temperature can be further reduced by 15 and 5℃respectively.展开更多
Inexpressible Island is a small rocky island in Terra Nova Bay,Victoria Land,Antarctica,which is an area with limited human activities.Understanding the distribution of antibiotic-resistance genes(ARGs)and virulence f...Inexpressible Island is a small rocky island in Terra Nova Bay,Victoria Land,Antarctica,which is an area with limited human activities.Understanding the distribution of antibiotic-resistance genes(ARGs)and virulence factor genes(VFGs)in this environment can provide key information on their potential risks to humans and their roles for microbial survival.In this study,we investigated the ARGs and VFGs in lake sediments from Inexpressible Island using metagenomic sequencing.We identified 11,502,071 open-reading frames(ORFs),with 1,749 classified as ARGs and 6,838 as VFGs.The dominant ARGs were associated with antibiotic target alteration and efflux pump mechanisms,while the VFGs were related to adher-ence and immune modulation functions.While associated within microbial genomes,these ARGs and VFGs were mobile genetic elements like viruses and insertion sequences,distinct from ecosystems with strong human influence.We identified 974 metagenome-assembled genomes(MAGs),with 465 being medium-to-high quality.Of these,325(69.9%)contained ARGs,primarily affiliated with Actinomycetota and Pseudomonadota.Additionally,269 MAGs contained VFGs,with 174 MAGs carrying both ARGs and VFGs,highlighting significant microbial antibiotic resistance and pathogenic potential.Our findings highlight the need for ongoing monitoring of ARGs and VFGs in Antarctica,particularly in light of increasing human activity and climate change.展开更多
Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,a...Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,as an environmentally friendly method for synthesizing ammonia,not only mitigates the reliance on current ammonia synthesis processes fed by traditional fossil fuels but also effectively reduces nitrate pollution resulting from agricultural and industrial activities.This review explores the fundamental principles of electrocata lytic nitrate reduction,focusing on the key steps of electron transfer and ammonia formation.Additionally,it summarizes the critical factors influencing the performance and selectivity of the reaction,including the properties of the electrolyte,operating voltage,electrode materials,and design of the electrolytic cell.Further discussion of recent advances in electrocatalysts,including pure metal catalysts,metal oxide catalysts,non-metallic catalysts,and composite catalysts,highlights their significant roles in enhancing both the efficiency and selectivity of electrocata lytic nitrate to ammonia(NRA)reactions.Critical challenges for the industrial NRA trials and further outlooks are outlined to propel this strategy toward real-world applications.Overall,the review provides an in-depth overview and comprehensive understanding of electrocata lytic NRA technology,thereby promoting further advancements and innovations in this domain.展开更多
Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materia...Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materials as a result of ongoing technological advancements.These novel materials possess intrinsic pore structures or can be assembled to form lamellar membrane channels for selective transport of water or solutes(e.g.,NaCl).Still,in real applications,the results fall below the theoretical predictions,and a few properties,including large-scale fabrication,mechanical strength,and chemical stability,also have an impact on the overall effectiveness of those materials.In view of this,we develop a new evaluation framework in the form of radar charts with five dimensions(i.e.,water permeance,water/NaCl selectivity,membrane cost,scale of development,and stability)to assess the advantages,disadvantages,and potential of state-of-the-art and newly developed desalination membranes.In this framework,the reported thin film nanocomposite membranes and membranes developed from novel materials were compared with the state-of-the-art thin film composite membranes.This review will demonstrate the current advancements in novel membrane materials and bridge the gap between different desalination membranes.In this review,we also point out the prospects and challenges of next-generation membranes for desalination applications.We believe that this comprehensive framework may be used as a future reference for designing next-generation desalination membranes and will encourage further research and development in the field of membrane technology,leading to new insights and advancements.展开更多
As one of the most important components of the vanadium redox flow battery （VRFB）, the electrolyte can impose a significant impact on cell properties, performance and capital cost. In particular, the electrolyte com...As one of the most important components of the vanadium redox flow battery （VRFB）, the electrolyte can impose a significant impact on cell properties, performance and capital cost. In particular, the electrolyte composition will influence energy density, operating temperature range and the practical applications of the VRFB. Various approaches to increase the energy density and operating temperature range have been proposed. The presence of electrolyte impurities, or the addition of a small amount of other chemical species into the vanadium solution can alter the stability of the electrolyte and influence cell perfor- mance, operating temperature range, energy density, electrochemical kinetics and cost effectiveness. This review provides a detailed overview of research on electrolyte additives including stabilizing agents, im- mobilizing agents, kinetic enhancers, as well as electrolyte impurities and chemical reductants that can be used for different purposes in the VRFBs.展开更多
Strata failure is a principal hazard in open cut coal mining as it has the potential to cause multiple fatalities.Prior to the excavation of any slope,a geotechnical assessment should review the likely slope performan...Strata failure is a principal hazard in open cut coal mining as it has the potential to cause multiple fatalities.Prior to the excavation of any slope,a geotechnical assessment should review the likely slope performance,including the risk of slope failure.Controls to manage this risk to an acceptable level should accompany the geotechnical analysis.A survey of 43 practising geotechnical engineers indicated that kinematic and 2D limit equilibrium analyses were the methods most commonly applied to analyse excavated slope stability.While these methods are well established and widely applied in the broad rock engineering disciplines(e.g.civil,hard rock),a recent review of over 60 slope failures suggests these methods have limited suitability for modelling the complex failure mechanisms observed in excavated coal mine slopes.Kinematic techniques do not adequately capture the rock mass component of excavated slope failure and do not provide a geospatial location of potential failure,while 2D limit equilibrium techniques do not adequately capture the 3D mechanisms of excavated slope failures.Methods which do consider the 3D mechanisms of slope failure are summarized for industry consideration and application.展开更多
A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At...A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At the time, a continuous miner was being used to mine a longwall development gate road through heavily structured coal, at a depth of approximately 550 m. A number of pre-cursor bumps had occurred on previous shifts, emanating from the coal ribs of the roadway, in proximity to the coal face.This paper reviews the geological, geotechnical and mining conditions and circumstances leading up to the coal burst event; and presents and discusses the available evidence and possible interpretations relating to the geomechanical behaviour mechanisms that may have been critical factors in this incident. The paper also discusses some key technical and operational considerations of ground support systems and mining practices and strategies needed for operating in such conditions in the future.展开更多
The service failure of rock bolts and cable bolts are frequently reported issues in underground coal mines. Whilst numerous experimental investigations concerned with the service failure of bolts have been conducted, ...The service failure of rock bolts and cable bolts are frequently reported issues in underground coal mines. Whilst numerous experimental investigations concerned with the service failure of bolts have been conducted, numerical modelling offers an alternative approach in evaluating the factors contributing to service failures of bolts in underground mines. In this study, analysis of the influence of groundwater and tensile stress on bolts in underground coal mines was studied through the numerical modelling of a grouted bolt in the immediate roadway roof. Bolt tensile stress and groundwater dripping rates in the immediate roadway roof were analysed using a package based on finite element method to assess the effect of coal roof thickness and claystone bands, as main contributors of known service failures of bolts in roadways of underground coal mines. Increasing coal roof thickness was found to increase bolt dripping rates. Probable location of stress corrosion cracking (SCC) occurrence was established through examining the shift and increase in maximum bolt tensile stress that was exhibited along the bolt length with increasing coal roof thickness. Claystone bands situated at the top and centre horizon of a grouted bolt produced lower bolt dripping rates compared with scenarios with no claystone bands. Intersecting claystone bands at the centre horizon of a bolt for a fully grouted bolt could increase the likelihood of SCC corrosion and bolt failure by contributing to microbial corrosion processes and grout fracturing by tensile stress. This study improves the understanding the bolt failure associated with the presence of groundwater and changing stress environments, which in turn is imperative in formulating strategies to mitigate support element failures and improve the ground support viability.展开更多
The study of flow behaviour of water-sand mixtures in fractured rocks is of great necessity to understand the producing mechanism and prevention of water inrush and sand gushing accidents.A self-developed seepage test...The study of flow behaviour of water-sand mixtures in fractured rocks is of great necessity to understand the producing mechanism and prevention of water inrush and sand gushing accidents.A self-developed seepage test system is used in this paper to conduct laboratory experiments in order to study the influence of the particle size distribution,the void ratio,and the initial mass of Aeolian sand on the flow behavior.It is concluded that the water flow velocity is insensitive to the initial mass of the Aeolian sand but increases with the power exponent in the Talbot formula and the specimen height.The outflow of the Aeolian sand increases with the power exponent in the Talbot formula,the specimen height,and the initial mass of the Aeolian sand.Besides,the outflow of the Aeolian sand changes exponentially with the water flow velocity.Finally,it is found that the fractured specimen has a maximum sand filtration capacity beyond which the outflow of the Aeolian sand significantly increases with the initial mass of the Aeolian sand.展开更多
Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiat...Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt.In this study,the role of Acidithiobacillus ferrooxidans(A.ferrooxidans)bacterium in the occurrence of pitting corrosion in cable bolts was studied.Stressed coupons,made from the wires of cable bolts,were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A.ferrooxidans and geomaterials.It was observed that A.ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment.The presence of geomaterials slightly affected the p H of the environment;however,it did not have any significant influence on the corrosion activity of A.ferrooxidans.This study suggests that the common bacterium A.ferrooxidans found in many underground environments can be a threat to cable bolts'integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking.展开更多
We live in an era of rapid urbanization as many cities are experiencing an unprecedented rate of population growth and congestion.Public transport is playing an increasingly important role in urban mobility with a nee...We live in an era of rapid urbanization as many cities are experiencing an unprecedented rate of population growth and congestion.Public transport is playing an increasingly important role in urban mobility with a need to move people and goods efficiently around the city.With such pressures on existing public transportation systems,this paper investigates the opportunities to use social media to more effectively engage with citizens and customers using such services.This research forms a case study of the use of passively collected forms of big data in cities-focusing on Sydney,Australia.Firstly,it examines social media data(Tweets)related to public transport performance.Secondly,it joins this to longitudinal big data-delay information continuously broadcast by the network over a year,thus forming hundreds of millions of data artifacts.Topics,tones,and sentiment are modeled using machine learning and Natural Language Processing(NLP)techniques.These resulting data,and models,are compared to opinions derived from a citizen survey among users.The validity of such data and models versus the intentions of users,in the context of systems that monitor and improve transport performance,are discussed.As such,key recommendations for developing Smart Cities were formed in an applied research context based on these data and techniques.展开更多
Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be ...Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be required to focus their cooling resources more intensively to manage a challenging thermal environment where virgin coal temperatures over 50 °C at a depth of 500 m are expected. Currently, mine cooling systems are employed to maintain the wet bulb temperatures(WBT) to below 27 °C at which point the risks of heat stroke or other heat related issues are manageable. The capacities of these systems are in the range of 6–10 MW refrigeration power. The relationship between high working temperature environment and injury frequency rates is well established. Therefore, provision of appropriate cooling strategies and understanding their optimum performance and suitability are important to Australian coal mines of the future. This paper evaluates the underground temperature profiles of deep, gassy coal mines with propensity for spontaneous combustion and proposes the long term cooling pathways to effectively manage the thermal hazards. Thermodynamic modeling is performed on a longwall face and includes air leakage effects from goaf streams at various locations along the longwall face. The strategy summarizes the application of underground bulk air cooling, chilled water sprays on the shearer and the resulting temperature profiles. Considering the new mining projects planned for the Bowen Basin region, a review of implementable cooling strategies such as mid-gate mobile bulk air coolers(BACs), spot coolers, underground bulk air cooling and the use of chilled water to enhance the positional efficiency of cooling plants,are discussed in this paper. Finally, the comparison of ‘rental' versus ‘ownership' of cooling plants is analysed as part of long-term cooling strategies.展开更多
This paper presents a new risk assessment methodology for coal mine excavated slopes. This new empirical-statistical slope.stability assessment m. ethodology （SSAM! is intended for use by geotechnical engineers at bo...This paper presents a new risk assessment methodology for coal mine excavated slopes. This new empirical-statistical slope.stability assessment m. ethodology （SSAM! is intended for use by geotechnical engineers at both the design review and operational stages of a mine＇s life to categonse the risk of an excavated coal mine slope. A likelihood of failure is determined using a new slope stability classification system for excavated coal mine slopes developed using a database of 119 intact and failed case studies sourced from open cut coal mines in Australia. Consequence of failure is based on slope height and stand-off distance at the toe of the excavated slope. Results are presented in a new risk matrix, with slope risk being divided into low, medium and high categories. The SSAM is put forward as a new risk assess- ment methodology to assess the potential for, and consequence of, excavated coal mine slope failure. Unlike existing classification systems, assumptions about the likely failure mode or mechanism are not required. Instead, the SSAM applies an approach which compares the conditions present within the exca- vated slope face, with the known past performance of slopes with similar geotechnical and geometrical conditions, to estimate the slope＇s propensity for failure. The SSAM is novel in that it considers the depo- sitional history of strata in an excavated slope and how this sequence affects slope stability. It is further novel in that it does not require explicit measurements of intact rock, rock mass and/or defect strength to rapidly calculate a slope＇s likelihood of failure and overall risk. Ratings can be determined entirely from visual observations of the excavated slope face. The new SSAM is designed to be used in conjunction with existing slope stability assessment tools.展开更多
基金support from the Australian Research Council’s Industrial Transformation Research Hub funding scheme(project IH190100009).
文摘This study details a comprehensive approach focusing on the effective separation of light rare earth elements(REEs)via solvent extraction technique.A stock solution containing lanthanum,cerium,neodymium,praseodymium,and samarium was prepared by dissolving their pure mixed oxide(reclaimed from spent Ni-MH batteries)in a diluted HCl solution.Key extractants,including bis(2,4,4-trimethylpentyl)phosphinic acid(Cyanex 272),Cyanex 572,trialkylphosphine oxide(Cyanex 923),and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC 88A),along with tributyl phosphate(TBP)as a phase modifier,were utilized to form organic systems.The extraction behavior and separability of these systems at various pH levels as well as their extraction mechanisms were investigated.The results demonstrated a direct relationship between the extraction trend and the experimental pH value,with enhanced selectivity when TBP was added.Notably,Nd and Pr exhibited similar extraction behaviors,with minor deviations from Ce,making their separation difficult to achieve.Sm extraction followed a distinct trend,allowing for its separation from other elements at pH≤2.In contrast,La exhibited a low affinity for coordination with extractants when pH was≤3.5,facilitating the separation of other elements from La,which could then be isolated in the raffinate.Among the studied organic systems,combinations of Cyanex 572 and PC 88A with TBP demonstrated superior performance in element separation.Optimum separation factors were calculated withβ_(Ce/La)=12,βNd/La=87,β_(Pr/La)=127,andβ_(Sm/La)=3191 for the former,andβ_(Sm/Ce)=54,β_(Sm/Nd)=20,andβ_(Sm/Pr)=14 for the latter.These findings provide valuable insights for selecting extraction systems and designing experiments for the effective solvent extraction separation of light REEs from their mixture.
基金the National Natural Science Foundation of China(NSFC)(62103283)the Australia Research Council’s Discovery Pro-jects Scheme(DP220100355).
文摘1.Background In the chemical industry,process plants-commonly referred to as plantwide systems-typically consist of many process units(unit operations).Driven by the considerable economic efficiency offered by complex and interactive process designs,modern plantwide systems are becoming increasingly sophisticated.The operation of these processes is typically characterized by the complexity of individual units(subsystems)and the intricate interactions between geographically distributed units through networks of material and energy flows,as well as control loops[1].
文摘The effectiveness of industrial character recognition on cast steel is often compromised by factors such as corrosion,surface defects,and low contrast,which hinder the extraction of reliable visual information.The problem is further compounded by the scarcity of large-scale annotated datasets and complex noise patterns in real-world factory environments.This makes conventional OCR techniques and standard deep learning models unreliable.To address these limitations,this study proposes a unified framework that integrates adaptive image preprocessing with collaborative reasoning among LLMs.A Biorthogonal 4.4(bior4.4)wavelet transform is adaptively tuned using DE to enhance character edge clarity,suppress background noise,and retain morphological structure,thereby improving input quality for subsequent recognition.A structured three-round debate mechanism is further introduced within a multi-agent architecture,employing GPT-4o and Gemini-2.0-flash as role-specialized agents to perform complementary inference and achieve consensus.The proposed system is evaluated on a proprietary dataset of 48 high-resolution images collected under diverse industrial conditions.Experimental results show that the combination of DE-based enhancement and multi-agent collaboration consistently outperforms traditional baselines and ablated models,achieving an F1-score of 94.93%and an LCS accuracy of 93.30%.These results demonstrate the effectiveness of integrating signal processing with multi-agent LLM reasoning to achieve robust and interpretable OCR in visually complex and data-scarce industrial environments.
文摘Polymer gears are increasingly replacing metal gears in applications with low to medium torque.Traditionally,polymer gears have been manufactured using injection molding,but additive manufacturing(AM)is becoming increasingly common.Among the different types of polymer gears,nylon gears are particularly popular.However,there is currently very limited understanding of the wear resistance of nylon gears and of the impact of the manufacturing method on gear wear performance.The aims of this work are(a)to study the wear process of nylon gears made using the conventional injection molding method and two popularly used AM methods,namely,fused deposition modeling and selective laser sintering,(b)to compare and understand the wear performance by monitoring the evolution of the gear surfaces of the teeth,and(c)to study the effect of wear on the gear dynamics by analyzing gearbox vibration signals.This article presents experimental work,data analysis of the wear processes using molding and image analysis techniques,as well as the vibration data collected during gear wear tests.It also provides key results and further insights into the wear performance of the tested nylon gears.The information gained in this study is useful for better understanding the degradation process of additively manufactured nylon gears.
文摘Manufacturers must identify and classify various defects in automotive sealing rings to ensure product quality.Deep learning algorithms show promise in this field,but challenges remain,especially in detecting small-scale defects under harsh industrial conditions with multimodal data.This paper proposes an enhanced version of You Only Look Once(YOLO)v8 for improved defect detection in automotive sealing rings.We introduce the Multi-scale Adaptive Feature Extraction(MAFE)module,which integrates Deformable ConvolutionalNetwork(DCN)and Spaceto-Depth(SPD)operations.This module effectively captures long-range dependencies,enhances spatial aggregation,and minimizes information loss of small objects during feature extraction.Furthermore,we introduce the Blur-Aware Wasserstein Distance(BAWD)loss function,which improves regression accuracy and detection capabilities for small object anchor boxes,particularly in scenarios involving defocus blur.Additionally,we have constructed a high-quality dataset of automotive sealing ring defects,providing a valuable resource for evaluating defect detection methods.Experimental results demonstrate our method’s high performance,achieving 98.30% precision,96.62% recall,and an inference speed of 20.3 ms.
基金Funded by National Natural Science Foundation of China(No.52494933)。
文摘Fe-doped CuCrO_(2) catalyst CuCr_(1-x)Fe_xO_(2) series were prepared by the sol-gel method with different Fe contents.The structure and properties of the catalysts were investigated by XRD(X-ray diffraction),SEM(scanning electron microscope),and XPS(X-ray photoelectron spectroscopy)and the purification effect on NO_(x) and PM was measured through simulated emission experiments.The results indicate that CuCrO_(2) catalyst has good catalytic activity,the maximum NO_(x) conversion rate can be up to 28.15%,and the ignition temperature of PM can be reduced to 285℃.When the molecular ratio of Cr:Fe=9:1,the catalyst can achieve better catalytic effect,the maximum NO_(x) conversion rate will be up to 30.25%and the PM ignition temperature can be reduced to 280℃.In addition,the catalytic activity of catalyst supported on different carriers was also studied.The results show that catalyst on SiC foam ceramic carrier has better catalytic activity than that on cordierite honeycomb ceramic carrier.The maximum NO_(x) conversion of CuCrO_(2) and CuCr_(0.9)Fe_(0.1)O_(2) can be increased by 0.72%and 1.33%respectively,and the PM ignition temperature can be further reduced by 15 and 5℃respectively.
基金supported by the National Natu-ral Science Foundation of China(42171138 and 32241037)the Ministry of Science and Technology of the People's Republic of China(2021YFC2300904).
文摘Inexpressible Island is a small rocky island in Terra Nova Bay,Victoria Land,Antarctica,which is an area with limited human activities.Understanding the distribution of antibiotic-resistance genes(ARGs)and virulence factor genes(VFGs)in this environment can provide key information on their potential risks to humans and their roles for microbial survival.In this study,we investigated the ARGs and VFGs in lake sediments from Inexpressible Island using metagenomic sequencing.We identified 11,502,071 open-reading frames(ORFs),with 1,749 classified as ARGs and 6,838 as VFGs.The dominant ARGs were associated with antibiotic target alteration and efflux pump mechanisms,while the VFGs were related to adher-ence and immune modulation functions.While associated within microbial genomes,these ARGs and VFGs were mobile genetic elements like viruses and insertion sequences,distinct from ecosystems with strong human influence.We identified 974 metagenome-assembled genomes(MAGs),with 465 being medium-to-high quality.Of these,325(69.9%)contained ARGs,primarily affiliated with Actinomycetota and Pseudomonadota.Additionally,269 MAGs contained VFGs,with 174 MAGs carrying both ARGs and VFGs,highlighting significant microbial antibiotic resistance and pathogenic potential.Our findings highlight the need for ongoing monitoring of ARGs and VFGs in Antarctica,particularly in light of increasing human activity and climate change.
基金supported by the National Key Research and Development Program of China(2023YFE0120900)the National Natural Science Foundation of China(52377160)+2 种基金the National Natural Science Foundation of China National Young Talents Project(GYKP010)Shaanxi Provincial Natural Science Program(2023-JCYB-425)Xi’an Jiaotong University Young Top Talents Program。
文摘Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,as an environmentally friendly method for synthesizing ammonia,not only mitigates the reliance on current ammonia synthesis processes fed by traditional fossil fuels but also effectively reduces nitrate pollution resulting from agricultural and industrial activities.This review explores the fundamental principles of electrocata lytic nitrate reduction,focusing on the key steps of electron transfer and ammonia formation.Additionally,it summarizes the critical factors influencing the performance and selectivity of the reaction,including the properties of the electrolyte,operating voltage,electrode materials,and design of the electrolytic cell.Further discussion of recent advances in electrocatalysts,including pure metal catalysts,metal oxide catalysts,non-metallic catalysts,and composite catalysts,highlights their significant roles in enhancing both the efficiency and selectivity of electrocata lytic nitrate to ammonia(NRA)reactions.Critical challenges for the industrial NRA trials and further outlooks are outlined to propel this strategy toward real-world applications.Overall,the review provides an in-depth overview and comprehensive understanding of electrocata lytic NRA technology,thereby promoting further advancements and innovations in this domain.
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administration Region,China(SRFS2021-7S04)Partial support was also received from the Seed Funding for Strategic Interdisciplinary Research Scheme(102010174)+1 种基金Seed Fund for Basic Research(202111159075)of The University of Hong KongIn addition,part of this work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement INTELWAT(No 958454).
文摘Membrane desalination is an economical and energy-efficient method to meet the current worldwide water scarcity.However,state-of-the-art reverse osmosis membranes are gradually being replaced by novel membrane materials as a result of ongoing technological advancements.These novel materials possess intrinsic pore structures or can be assembled to form lamellar membrane channels for selective transport of water or solutes(e.g.,NaCl).Still,in real applications,the results fall below the theoretical predictions,and a few properties,including large-scale fabrication,mechanical strength,and chemical stability,also have an impact on the overall effectiveness of those materials.In view of this,we develop a new evaluation framework in the form of radar charts with five dimensions(i.e.,water permeance,water/NaCl selectivity,membrane cost,scale of development,and stability)to assess the advantages,disadvantages,and potential of state-of-the-art and newly developed desalination membranes.In this framework,the reported thin film nanocomposite membranes and membranes developed from novel materials were compared with the state-of-the-art thin film composite membranes.This review will demonstrate the current advancements in novel membrane materials and bridge the gap between different desalination membranes.In this review,we also point out the prospects and challenges of next-generation membranes for desalination applications.We believe that this comprehensive framework may be used as a future reference for designing next-generation desalination membranes and will encourage further research and development in the field of membrane technology,leading to new insights and advancements.
文摘As one of the most important components of the vanadium redox flow battery （VRFB）, the electrolyte can impose a significant impact on cell properties, performance and capital cost. In particular, the electrolyte composition will influence energy density, operating temperature range and the practical applications of the VRFB. Various approaches to increase the energy density and operating temperature range have been proposed. The presence of electrolyte impurities, or the addition of a small amount of other chemical species into the vanadium solution can alter the stability of the electrolyte and influence cell perfor- mance, operating temperature range, energy density, electrochemical kinetics and cost effectiveness. This review provides a detailed overview of research on electrolyte additives including stabilizing agents, im- mobilizing agents, kinetic enhancers, as well as electrolyte impurities and chemical reductants that can be used for different purposes in the VRFBs.
基金The research presented in this paper is funded by the Austrlian Coal Association Research Program(ACARP),grant no.C25078.
文摘Strata failure is a principal hazard in open cut coal mining as it has the potential to cause multiple fatalities.Prior to the excavation of any slope,a geotechnical assessment should review the likely slope performance,including the risk of slope failure.Controls to manage this risk to an acceptable level should accompany the geotechnical analysis.A survey of 43 practising geotechnical engineers indicated that kinematic and 2D limit equilibrium analyses were the methods most commonly applied to analyse excavated slope stability.While these methods are well established and widely applied in the broad rock engineering disciplines(e.g.civil,hard rock),a recent review of over 60 slope failures suggests these methods have limited suitability for modelling the complex failure mechanisms observed in excavated coal mine slopes.Kinematic techniques do not adequately capture the rock mass component of excavated slope failure and do not provide a geospatial location of potential failure,while 2D limit equilibrium techniques do not adequately capture the 3D mechanisms of excavated slope failures.Methods which do consider the 3D mechanisms of slope failure are summarized for industry consideration and application.
文摘A coal burst occurred on 15 April, 2014 at the Austar Coal Mine, located west of Newcastle, NSW,Australia. The burst resulted in fatal injuries to two men working as part of the mining crew at the development face. At the time, a continuous miner was being used to mine a longwall development gate road through heavily structured coal, at a depth of approximately 550 m. A number of pre-cursor bumps had occurred on previous shifts, emanating from the coal ribs of the roadway, in proximity to the coal face.This paper reviews the geological, geotechnical and mining conditions and circumstances leading up to the coal burst event; and presents and discusses the available evidence and possible interpretations relating to the geomechanical behaviour mechanisms that may have been critical factors in this incident. The paper also discusses some key technical and operational considerations of ground support systems and mining practices and strategies needed for operating in such conditions in the future.
文摘The service failure of rock bolts and cable bolts are frequently reported issues in underground coal mines. Whilst numerous experimental investigations concerned with the service failure of bolts have been conducted, numerical modelling offers an alternative approach in evaluating the factors contributing to service failures of bolts in underground mines. In this study, analysis of the influence of groundwater and tensile stress on bolts in underground coal mines was studied through the numerical modelling of a grouted bolt in the immediate roadway roof. Bolt tensile stress and groundwater dripping rates in the immediate roadway roof were analysed using a package based on finite element method to assess the effect of coal roof thickness and claystone bands, as main contributors of known service failures of bolts in roadways of underground coal mines. Increasing coal roof thickness was found to increase bolt dripping rates. Probable location of stress corrosion cracking (SCC) occurrence was established through examining the shift and increase in maximum bolt tensile stress that was exhibited along the bolt length with increasing coal roof thickness. Claystone bands situated at the top and centre horizon of a grouted bolt produced lower bolt dripping rates compared with scenarios with no claystone bands. Intersecting claystone bands at the centre horizon of a bolt for a fully grouted bolt could increase the likelihood of SCC corrosion and bolt failure by contributing to microbial corrosion processes and grout fracturing by tensile stress. This study improves the understanding the bolt failure associated with the presence of groundwater and changing stress environments, which in turn is imperative in formulating strategies to mitigate support element failures and improve the ground support viability.
基金financially supported by the National Natural Science Foundation of China(Nos.41807209,51778215,51708185,and 51974293)the Young Teacher Foundation of HPU(No.2019XQG-19)+3 种基金the Henan Provincial Youth Talent Promotion Program(No.2020HYTP003)the Jiangsu Province Science Foundation for Youths(No.BK20180658)the Doctor Foundation of Henan Polytechnic University(Nos.B2017-51 and B2017-53)China Postdoctoral Science Foundation(No.2018M632422)。
文摘The study of flow behaviour of water-sand mixtures in fractured rocks is of great necessity to understand the producing mechanism and prevention of water inrush and sand gushing accidents.A self-developed seepage test system is used in this paper to conduct laboratory experiments in order to study the influence of the particle size distribution,the void ratio,and the initial mass of Aeolian sand on the flow behavior.It is concluded that the water flow velocity is insensitive to the initial mass of the Aeolian sand but increases with the power exponent in the Talbot formula and the specimen height.The outflow of the Aeolian sand increases with the power exponent in the Talbot formula,the specimen height,and the initial mass of the Aeolian sand.Besides,the outflow of the Aeolian sand changes exponentially with the water flow velocity.Finally,it is found that the fractured specimen has a maximum sand filtration capacity beyond which the outflow of the Aeolian sand significantly increases with the initial mass of the Aeolian sand.
基金funding provided by the Australian Research Council(ARC)Linkage Projects(Nos.100200238 and 140100153)supported by Jennmar Australia Pty Ltd+5 种基金Glencore Australia Holdings Pty LtdIllawarra Coal Holdings Pty LtdSpringvale Coal Pty LtdAnglo Operations Pty LtdAnglo Coal AustraliaNarrabri Coal Operations Pty Ltd。
文摘Reports on corrosion failure of cable bolts,used in mining and civil industries,have been increasing in the past two decades.The previous studies found that pitting corrosion on the surface of a cable bolt can initiate premature failure of the bolt.In this study,the role of Acidithiobacillus ferrooxidans(A.ferrooxidans)bacterium in the occurrence of pitting corrosion in cable bolts was studied.Stressed coupons,made from the wires of cable bolts,were immersed in testing bottles containing groundwater collected from an underground coal mine and a mixture of A.ferrooxidans and geomaterials.It was observed that A.ferrooxidans caused pitting corrosion on the surface of cable bolts in the near-neutral environment.The presence of geomaterials slightly affected the p H of the environment;however,it did not have any significant influence on the corrosion activity of A.ferrooxidans.This study suggests that the common bacterium A.ferrooxidans found in many underground environments can be a threat to cable bolts'integrity by creating initiation points for other catastrophic failures such as stress corrosion cracking.
文摘We live in an era of rapid urbanization as many cities are experiencing an unprecedented rate of population growth and congestion.Public transport is playing an increasingly important role in urban mobility with a need to move people and goods efficiently around the city.With such pressures on existing public transportation systems,this paper investigates the opportunities to use social media to more effectively engage with citizens and customers using such services.This research forms a case study of the use of passively collected forms of big data in cities-focusing on Sydney,Australia.Firstly,it examines social media data(Tweets)related to public transport performance.Secondly,it joins this to longitudinal big data-delay information continuously broadcast by the network over a year,thus forming hundreds of millions of data artifacts.Topics,tones,and sentiment are modeled using machine learning and Natural Language Processing(NLP)techniques.These resulting data,and models,are compared to opinions derived from a citizen survey among users.The validity of such data and models versus the intentions of users,in the context of systems that monitor and improve transport performance,are discussed.As such,key recommendations for developing Smart Cities were formed in an applied research context based on these data and techniques.
基金support received from Anglo American Metallurgical CoalAnglo American Operations (Pty) Ltd in preparing this paper
文摘Cooling of coal mines in the Bowen Basin, characterized by steep geothermal gradient, is presently achieved mostly through rental surface bulk air cooling in summer months. This paper argues that future mines will be required to focus their cooling resources more intensively to manage a challenging thermal environment where virgin coal temperatures over 50 °C at a depth of 500 m are expected. Currently, mine cooling systems are employed to maintain the wet bulb temperatures(WBT) to below 27 °C at which point the risks of heat stroke or other heat related issues are manageable. The capacities of these systems are in the range of 6–10 MW refrigeration power. The relationship between high working temperature environment and injury frequency rates is well established. Therefore, provision of appropriate cooling strategies and understanding their optimum performance and suitability are important to Australian coal mines of the future. This paper evaluates the underground temperature profiles of deep, gassy coal mines with propensity for spontaneous combustion and proposes the long term cooling pathways to effectively manage the thermal hazards. Thermodynamic modeling is performed on a longwall face and includes air leakage effects from goaf streams at various locations along the longwall face. The strategy summarizes the application of underground bulk air cooling, chilled water sprays on the shearer and the resulting temperature profiles. Considering the new mining projects planned for the Bowen Basin region, a review of implementable cooling strategies such as mid-gate mobile bulk air coolers(BACs), spot coolers, underground bulk air cooling and the use of chilled water to enhance the positional efficiency of cooling plants,are discussed in this paper. Finally, the comparison of ‘rental' versus ‘ownership' of cooling plants is analysed as part of long-term cooling strategies.
基金funded by the Australian Coal Association Research Program(ACARP)
文摘This paper presents a new risk assessment methodology for coal mine excavated slopes. This new empirical-statistical slope.stability assessment m. ethodology （SSAM! is intended for use by geotechnical engineers at both the design review and operational stages of a mine＇s life to categonse the risk of an excavated coal mine slope. A likelihood of failure is determined using a new slope stability classification system for excavated coal mine slopes developed using a database of 119 intact and failed case studies sourced from open cut coal mines in Australia. Consequence of failure is based on slope height and stand-off distance at the toe of the excavated slope. Results are presented in a new risk matrix, with slope risk being divided into low, medium and high categories. The SSAM is put forward as a new risk assess- ment methodology to assess the potential for, and consequence of, excavated coal mine slope failure. Unlike existing classification systems, assumptions about the likely failure mode or mechanism are not required. Instead, the SSAM applies an approach which compares the conditions present within the exca- vated slope face, with the known past performance of slopes with similar geotechnical and geometrical conditions, to estimate the slope＇s propensity for failure. The SSAM is novel in that it considers the depo- sitional history of strata in an excavated slope and how this sequence affects slope stability. It is further novel in that it does not require explicit measurements of intact rock, rock mass and/or defect strength to rapidly calculate a slope＇s likelihood of failure and overall risk. Ratings can be determined entirely from visual observations of the excavated slope face. The new SSAM is designed to be used in conjunction with existing slope stability assessment tools.
