The design of casting gating system directly determines the solidification sequence,defect severity,and overall quality of the casting.A novel machine learning strategy was developed to design the counter pressure cas...The design of casting gating system directly determines the solidification sequence,defect severity,and overall quality of the casting.A novel machine learning strategy was developed to design the counter pressure casting gating system of a large thin-walled cabin casting.A high-quality dataset was established through orthogonal experiments combined with design criteria for the gating system.Spearman’s correlation analysis was used to select high-quality features.The gating system dimensions were predicted using a gated recurrent unit(GRU)recurrent neural network and an elastic network model.Using EasyCast and ProCAST casting software,a comparative analysis of the flow field,temperature field,and solidification field can be conducted to demonstrate the achievement of steady filling and top-down sequential solidification.Compared to the empirical formula method,this method eliminates trial-and-error iterations,reduces porosity,reduces casting defect volume from 11.23 cubic centimeters to 2.23 cubic centimeters,eliminates internal casting defects through the incorporation of an internally cooled iron,fulfilling the goal of intelligent gating system design.展开更多
Two gating systems namely stepped and tapered runners were used to cast strip samples with different thicknesses by CO2/silicate process using sand grain sizes of AFS 151 and 171. To assess the effect of mould coating...Two gating systems namely stepped and tapered runners were used to cast strip samples with different thicknesses by CO2/silicate process using sand grain sizes of AFS 151 and 171. To assess the effect of mould coating on the properties of thin wall ductile iron, half of the moulds were coated whilst the rest were not coated. Molten metal with the carbon equivalent of 4.29% was prepared and poured at 1 450 ℃. Microstructure of the specimens was analyzed by optical and scanning electron microscopes. Count, area fraction, roundness and diameter of the graphite nodules of the samples were measured by image analyzer. Brinell hardness and tensile tests of all the samples were also conducted. The results show that by using stepped runner gating system with uncoated and coarse sand mould, roundness and count of the graphite nodules decrease whereas diameter and area fraction increase. Although fine sand and coated mould cause longer distance of molten metal travel, hardness and strength of the samples decrease.展开更多
The gating system of a cylindrical magnesium casting has been designed by using multiple objective optimiza- tion and Taguchi method.Mold filling and solidification processes were simulated by using MAGMASOFT（？）. T...The gating system of a cylindrical magnesium casting has been designed by using multiple objective optimiza- tion and Taguchi method.Mold filling and solidification processes were simulated by using MAGMASOFT（？）. The simulation results indicate that the gating system design has a significant effect on the quality of magne- sium castings.In an effort to obtain the optimal design of gating system,the signal-to-noise （S/N） ratio was used to analyze the effect of various gating designs on cavity filling and casting quality by using a weighting method based on the design of an orthogonal array.Four gating system parameters,namely,ingate height, ingate width,runner height,runner width,were optimized with a consideration of multiple objective criteria including filling velocity,shrinkage porosity and product yield.展开更多
The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas.In this study,the slot gating system is employed to improve mold filling behavior and therefore,to improve the quality o...The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas.In this study,the slot gating system is employed to improve mold filling behavior and therefore,to improve the quality of aluminum castings produced in permanent molds.An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum flowing into permanent molds have been developed.Graphite molds transparent to X-rays are utilized which make it possible to observe the flow pattern through a number of vertically oriented gating systems.The investigation discovers that there are many influencing factors on the mold filling process.This paper focuses its research on some of the factors,such as the dimensions of the vertical riser and slot thickness,as well as roughness of the coating layer.The results indicate that molten metal can smoothly fill into casting cavity with a proper slot gating system.A bigger vertical riser,proper slot thickness and rougher coating can provide not only a better mold filling pattern,but also hot melt into the top of the cavity.A proper temperature gradient is obtainable,higher at the bottom and lower at the top of the casting cavity,which is in favor of feeding during casting solidification.展开更多
In foundries a lot of effort is done to minimize energy consumption in the production to reduce costs and hence increase the competitiveness. At the same time the foundries must live up to the increased demands for hi...In foundries a lot of effort is done to minimize energy consumption in the production to reduce costs and hence increase the competitiveness. At the same time the foundries must live up to the increased demands for high quality castings. Traditional gating systems are known for a straight tapered down runner, a well base and 90° bends in the runner system. Previous work has shown that the traditional way of designing gating systems creates high inconsistency in flow patterns during filling. In the streamlined gating systems there are no sharp changes in direction and a large effort is done to confine and control the flow of the molten metal during mould filling. The main objective in the work presented here is to use the principles of the streamlined gating systems to reduce the weight of the gating system relative to the traditional layouts. By reducing the weight of gating system and thereby improving yield, the amount of molten iron needed is also reduced, hence reducing the energy consumption for melting. Experiments in real production lines have proven that it is possible to achieve a reduction in the poured weight by using the streamlined gating systems. In a layout for casting of three valve housings in a vertically parted mould the weight of the gating system was reduced by 1.1 kg changing from the traditional layouts to the streamlined gating systems. This weight reduction corresponds in this case to a 20% weight reduction for the gating system. Using streamlined gating systems with fan gates to give a beneficial heat distribution in the castings may be an efficient tool to eliminate the need for heat treatment. In the experiments the change in gating system from the traditional layout to the streamlined layout removed the need for heat treatment. This obviously means a huge energy saving in the foundry. The energy consumption for heat treatment of iron has been found to be 0.489 kWh/ kg. The valve housing in the experiments weighs 3 kg so when the need for heat treatment is removed, around 1.5 kWh is saved per casting. Along with the reduction in energy used the foundry also save the cost of handling the castings for the heat treatment and the production times is reduced considerably When the moulds for the vertical layout is produced on a DISAMATIC that produces 350 moulds an hour the total energy saved per hour for both melting and heat treatment becomes 2,000 kWh and per eight hour work day 16,000 kWh. Seen in this perspective the potential for saving energy in the foundries is substantial. Furthermore the experiments where ductile iron valve housings was cast also proved that it is possible to lower the pouring temperature from 1,400℃ to 1,300℃ without the risk of cold runs. This is possible due to a high flow rate during mould filling in combination with low velocities due to the use of fan gates. All of this has also been investigated in experiments using glass plate fronted moulds.展开更多
This work is concerned with the hydraulics and f low characterization in a pressurized,horizontal gating system with multiple ingates attached to a plate mold,using transparent water models.Runners with two different ...This work is concerned with the hydraulics and f low characterization in a pressurized,horizontal gating system with multiple ingates attached to a plate mold,using transparent water models.Runners with two different aspect ratios(w/h=0.5 and 2)and four different types of ingates(rectangular,convergent,divergent and venturi)were examined for their influence on flow behavior.Flow behavior was visualized using a high speed camera capable of capturing images up to 10,000 frames per second.Real time experimentation with a few runner–ingate combinations were carried out to validate the usefulness of water models in predicting the f illing behavior.Comparison of the approaches provided useful insights into the filling behavior in critical sections of the flow passages as well as the utility of water models towards understanding of the f illing behavior during real time casting.展开更多
High pressure die casting(HPDC) is a kind of near net shape manufacturing method. However, air entrapment in HPDC parts has serious effects upon the casting quality. In order to reduce the air entrapment defects in a ...High pressure die casting(HPDC) is a kind of near net shape manufacturing method. However, air entrapment in HPDC parts has serious effects upon the casting quality. In order to reduce the air entrapment defects in a AlSi10 MnMg alloy thin-wall longitudinal load-bearing beam produced by HPDC, different gating systems were designed and simulated by software Flow-3D to evaluate the entrapped air. Simulation results showed that when the beam is produced by the original designed gating system with a middle ingate, there exist obvious air entrapments in the critical area; the volume of air entrapment was reduced by replacing the middle ingate to an overflow well, and the filling of molten metal became more stable. When the middle ingate was removed for further improvement, the volume of air entrapment was decreased drastically. The parts with glossy surface and good microstructure have been successfully produced by using the final optimized gating system based on simulation results.展开更多
Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical si...Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%.展开更多
In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing method...In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing methods struggle to dynamically adjust cross-modal complementary strength to optimize fusion quality and lack effective mechanisms to model the dynamic evolution of emotions.To address these issues,we propose a multi-level dynamic gating and emotion transfer framework for multi-modal emotion recognition.A dynamic gating mechanism is applied across unimodal encoding,cross-modal alignment,and emotion transfer modeling,substantially improving noise robustness and feature alignment.First,we construct a unimodal encoder based on gated recurrent units and feature-selection gating to suppress intra-modal noise and enhance contextual representation.Second,we design a gated-attention crossmodal encoder that dynamically calibrates the complementary contributions of visual and audio modalities to the dominant textual features and eliminates redundant information.Finally,we introduce a gated enhanced emotion transfer module that explicitly models the temporal dependence of emotional evolution in dialogues via transfer gating and optimizes continuity modeling with a comparative learning loss.Experimental results demonstrate that the proposed method outperforms state-of-the-art models on the public MELD and IEMOCAP datasets.展开更多
Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has...Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.展开更多
Microbubbles have attracted considerable attention due to their distinctive properties,such as large surface area,inherent selfcompression,and exceptional mass transfer efficiency.These features render microbubbles va...Microbubbles have attracted considerable attention due to their distinctive properties,such as large surface area,inherent selfcompression,and exceptional mass transfer efficiency.These features render microbubbles valuable across a diverse range of industries,such as water treatment,mineral flotation,and the food industry.While several methods for microbubble generation exist,the gas–liquid membrane dispersion technique emerges as a reproducible and efficient alternative.Nevertheless,conventional approaches struggle to achieve active in situ control of bubble generation.In this study,we introduce an electrostatically responsive liquid gating system(ERLGS)designed for the active management of microbubble production.Utilizing electric fields and anionic surfactants,our system showcases the capability to dynamically regulate bubble size by manipulating the solid–liquid adsorption.Experiments confirm that this active control relies on the electrostatic adsorption and desorption of anionic surfactants,thereby regulating the interactions among the solid–liquid–gas interfaces.Our research elucidates the ERLGS's ability of precisely controlling the generation of bubbles in situ,enabling nearly one-order-of-magnitude change in bubble size,underscoring its applicability in various fields.展开更多
Attosecond light pulses have revolutionized the study of electron dynamics in materials by enabling the observation of ultrafast processes with unprecedented attosecond temporal resolution.They are primarily generated...Attosecond light pulses have revolutionized the study of electron dynamics in materials by enabling the observation of ultrafast processes with unprecedented attosecond temporal resolution.They are primarily generated through the process of high-order harmonic generation.This paper presents a comprehensive setup for attosecond pulse generation and measurement.Using a 900 nm,7 mJ,and 7 fs femtosecond laser with stabilized carrier-envelope phase,we employ polarization gating to generate a near single-cycle,linearly polarized pulse that interacts with neon gas to produce a broadband extreme-ultraviolet continuum with a cutoff photon energy of∼120 eV.The temporal and spectral characteristics of the generated single attosecond pulses are measured using an attosecond streak camera,and the pulse duration is determined to be 59 as through the frequency-resolved optical gating for complete reconstruction of attosecond bursts retrieval algorithm.As part of the Synergetic Extreme Condition User Facility,this setup will facilitate ultrafast research in transient absorption and photoelectron spectroscopy,providing global users with a powerful tool for studying electron dynamics in various materials.展开更多
The development of multi-stimuli-responsive luminescent system to address emerging demands is essential in anti-counterfeiting field.Herein,a photoswitchable system was reported,which was constructed from photoacid su...The development of multi-stimuli-responsive luminescent system to address emerging demands is essential in anti-counterfeiting field.Herein,a photoswitchable system was reported,which was constructed from photoacid sulfonato-merocyanine(MEH-D)serving as H+donor and diarylethene derivative(DAEA1)as acceptor.After capturing 2 equiv.HCl,the obtained fluorescent molecule DAE-A1-H showed solvatochromic property.Further on,benefiting from that MEH-D released protons and became a ring-closed isomer spiropyran(SP-D)under 440 nm irradiation,DAE-A1 was protonated,turning on fluorescence effect was realized in DAE-A1/MEH-D.In dark,a photo-activated reversible process was realized with SPD changed to MEH-D in situ system.In addition,the OF-DAE-A1-H/SP-D could efficiently and reversibly switch on/off its luminescence upon irradiation by UV–vis light.Significantly,the multi-stimuli-responsive system was successfully applied in logic gate and fluorescence ink,making it an efficient strategy for information encryption and decryption with higher security requirements.展开更多
QR codes are widely used in applications such as information sharing,advertising,and digital payments.However,their growing adoption has made them attractive targets for malicious activities,including malware distribu...QR codes are widely used in applications such as information sharing,advertising,and digital payments.However,their growing adoption has made them attractive targets for malicious activities,including malware distribution and phishing attacks.Traditional detection approaches rely on URL analysis or image-based feature extraction,whichmay introduce significant computational overhead and limit real-time applicability,and their performance often depends on the quality of extracted features.Previous studies in malicious detection do not fully focus on QR code securitywhen combining convolutional neural networks(CNNs)with recurrent neural networks(RNNs).This research proposes a deep learning model that integrates AlexNet for feature extraction,principal component analysis(PCA)for dimensionality reduction,and RNNs to detect malicious activity in QR code images.The proposed model achieves both efficiency and accuracy by transforming image data into a compact one-dimensional sequence.Experimental results,including five-fold cross-validation,demonstrate that the model using gated recurrent units(GRU)achieved an accuracy of 99.81%on the first dataset and 99.59%in the second dataset with a computation time of only 7.433 ms per sample.A real-time prototype was also developed to demonstrate deployment feasibility.These results highlight the potential of the proposed approach for practical,real-time QR code threat detection.展开更多
We investigate the impact of coupling on the reliability of the logic system as well as the logical stochastic resonance （LSR） phenomenon in the coupled logic gates system. It is found that compared with single logi...We investigate the impact of coupling on the reliability of the logic system as well as the logical stochastic resonance （LSR） phenomenon in the coupled logic gates system. It is found that compared with single logic gate, the coupled system could yield reliable logic outputs in a much wider noise region, which means coupling can obviously improve the reliability of the logic system and thus enhance the LSR effect. Moreover, we find that the enhancement is larger for larger system size, whereas for large enough size the enhancement seems to be saturated. Finally, we also examine the effect of coupling strength, it can be observed that the noise region where reliable logic outputs can be obtained evolves non-monotonically as the coupling strength increases, displaying a resonance-like effect.展开更多
The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molec...The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molecular sieving emerges as the most promising approach,but it will be significantly compromised at high temperatures due to the significant thermal motion.Here,we report a thermally robust zinc-based metal-organic framework(MOF)that can be synthesized on sub-kilogram scale and achieve exceptional C_(3)H_(6)/C_(3)H_(8) separation performances across a broad temperature range(298–353 K).Unlike conventional MOFs suffering from thermal lattice expansion to give poorer selectivity,this new MOF gives the adsorption capacity of C_(3)H_(6)essentially unchanged and that of C_(3)H_(8) negligible at elevated temperatures,outperforming most state-of-the-art adsorbents,in virtue of multiple hydrogen bonds at the aperture.Column breakthrough experiments confirmed the excellent separation capability,and showed no performance degradation over multi-round adsorption-desorption cycles at 353 K.This study addresses the critical challenge of the trade-off between temperature and selectivity in adsorptive separation,which offers new insights into the design of porous structures for highly effective separation at high temperatures.展开更多
In multi-domain neural machine translation tasks,the disparity in data distribution between domains poses significant challenges in distinguishing domain features and sharing parameters across domains.This paper propo...In multi-domain neural machine translation tasks,the disparity in data distribution between domains poses significant challenges in distinguishing domain features and sharing parameters across domains.This paper proposes a Transformer-based multi-domain-aware mixture of experts model.To address the problem of domain feature differentiation,a mixture of experts(MoE)is introduced into attention to enhance the domain perception ability of the model,thereby improving the domain feature differentiation.To address the trade-off between domain feature distinction and cross-domain parameter sharing,we propose a domain-aware mixture of experts(DMoE).A domain-aware gating mechanism is introduced within the MoE module,simultaneously activating all domain experts to effectively blend domain feature distinction and cross-domain parameter sharing.A loss balancing function is then added to dynamically adjust the impact of the loss function on the expert distribution,enabling fine-tuning of the expert activation distribution to achieve a balance between domains.Experimental results on multiple Chinese-to-English and English-to-French datasets demonstrate that our proposed method significantly outperforms baseline models in both BLEU,chrF,and COMET metrics,validating its effectiveness in multi-domain neural machine translation.Further analysis of the probability distribution of expert activations shows that our method achieves remarkable results in both domain differentiation and cross-domain parameter sharing.展开更多
Regulation of apoptosis represents a key parameter in all living organisms.In this paper,an input-induced logic-gated modular nanocalculator is designed to regulate cancer cell apoptosis by programmatically combining ...Regulation of apoptosis represents a key parameter in all living organisms.In this paper,an input-induced logic-gated modular nanocalculator is designed to regulate cancer cell apoptosis by programmatically combining and connecting logic gate modules with different functions.Via rational design of the various logic gate modules of the nanocalculator,different apoptosis related operations including cancer cell targeting,apoptosis induction,and apoptosis monitoring could be performed.Importantly,each of these logic gate modules could independently perform apoptosis related YES logic operations when ran separately.After combining each YES logic gate module into a logic circuit and connecting it to the GO scaffold to construct a logic-gated nanocalculator,the input-induced logic-gated modular nanocalculator could selectively enter cancer cells and control the drug release to logically apoptosis(output),by performing AND logic gate operations when inputs(nucleolin and H^(+)) were included at the same time.Moreover,evidence suggests that these efficient logical calculations proceed in cancer cell apoptosis regulation without the general limiations of lithography in nanotechnology.As such,this work provides a new vision for the construction of a logic-gated modular nanocalculator with logical calculation proficiency potentially useful in cancer therapy and the regulation of life.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52074246,52275390,52375394)the National Defense Basic Scientific Research Program of China(No.JCKY2020408B002)the Key R&D Program of Shanxi Province(No.202102050201011).
文摘The design of casting gating system directly determines the solidification sequence,defect severity,and overall quality of the casting.A novel machine learning strategy was developed to design the counter pressure casting gating system of a large thin-walled cabin casting.A high-quality dataset was established through orthogonal experiments combined with design criteria for the gating system.Spearman’s correlation analysis was used to select high-quality features.The gating system dimensions were predicted using a gated recurrent unit(GRU)recurrent neural network and an elastic network model.Using EasyCast and ProCAST casting software,a comparative analysis of the flow field,temperature field,and solidification field can be conducted to demonstrate the achievement of steady filling and top-down sequential solidification.Compared to the empirical formula method,this method eliminates trial-and-error iterations,reduces porosity,reduces casting defect volume from 11.23 cubic centimeters to 2.23 cubic centimeters,eliminates internal casting defects through the incorporation of an internally cooled iron,fulfilling the goal of intelligent gating system design.
文摘Two gating systems namely stepped and tapered runners were used to cast strip samples with different thicknesses by CO2/silicate process using sand grain sizes of AFS 151 and 171. To assess the effect of mould coating on the properties of thin wall ductile iron, half of the moulds were coated whilst the rest were not coated. Molten metal with the carbon equivalent of 4.29% was prepared and poured at 1 450 ℃. Microstructure of the specimens was analyzed by optical and scanning electron microscopes. Count, area fraction, roundness and diameter of the graphite nodules of the samples were measured by image analyzer. Brinell hardness and tensile tests of all the samples were also conducted. The results show that by using stepped runner gating system with uncoated and coarse sand mould, roundness and count of the graphite nodules decrease whereas diameter and area fraction increase. Although fine sand and coated mould cause longer distance of molten metal travel, hardness and strength of the samples decrease.
文摘The gating system of a cylindrical magnesium casting has been designed by using multiple objective optimiza- tion and Taguchi method.Mold filling and solidification processes were simulated by using MAGMASOFT（？）. The simulation results indicate that the gating system design has a significant effect on the quality of magne- sium castings.In an effort to obtain the optimal design of gating system,the signal-to-noise （S/N） ratio was used to analyze the effect of various gating designs on cavity filling and casting quality by using a weighting method based on the design of an orthogonal array.Four gating system parameters,namely,ingate height, ingate width,runner height,runner width,were optimized with a consideration of multiple objective criteria including filling velocity,shrinkage porosity and product yield.
文摘The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas.In this study,the slot gating system is employed to improve mold filling behavior and therefore,to improve the quality of aluminum castings produced in permanent molds.An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum flowing into permanent molds have been developed.Graphite molds transparent to X-rays are utilized which make it possible to observe the flow pattern through a number of vertically oriented gating systems.The investigation discovers that there are many influencing factors on the mold filling process.This paper focuses its research on some of the factors,such as the dimensions of the vertical riser and slot thickness,as well as roughness of the coating layer.The results indicate that molten metal can smoothly fill into casting cavity with a proper slot gating system.A bigger vertical riser,proper slot thickness and rougher coating can provide not only a better mold filling pattern,but also hot melt into the top of the cavity.A proper temperature gradient is obtainable,higher at the bottom and lower at the top of the casting cavity,which is in favor of feeding during casting solidification.
文摘In foundries a lot of effort is done to minimize energy consumption in the production to reduce costs and hence increase the competitiveness. At the same time the foundries must live up to the increased demands for high quality castings. Traditional gating systems are known for a straight tapered down runner, a well base and 90° bends in the runner system. Previous work has shown that the traditional way of designing gating systems creates high inconsistency in flow patterns during filling. In the streamlined gating systems there are no sharp changes in direction and a large effort is done to confine and control the flow of the molten metal during mould filling. The main objective in the work presented here is to use the principles of the streamlined gating systems to reduce the weight of the gating system relative to the traditional layouts. By reducing the weight of gating system and thereby improving yield, the amount of molten iron needed is also reduced, hence reducing the energy consumption for melting. Experiments in real production lines have proven that it is possible to achieve a reduction in the poured weight by using the streamlined gating systems. In a layout for casting of three valve housings in a vertically parted mould the weight of the gating system was reduced by 1.1 kg changing from the traditional layouts to the streamlined gating systems. This weight reduction corresponds in this case to a 20% weight reduction for the gating system. Using streamlined gating systems with fan gates to give a beneficial heat distribution in the castings may be an efficient tool to eliminate the need for heat treatment. In the experiments the change in gating system from the traditional layout to the streamlined layout removed the need for heat treatment. This obviously means a huge energy saving in the foundry. The energy consumption for heat treatment of iron has been found to be 0.489 kWh/ kg. The valve housing in the experiments weighs 3 kg so when the need for heat treatment is removed, around 1.5 kWh is saved per casting. Along with the reduction in energy used the foundry also save the cost of handling the castings for the heat treatment and the production times is reduced considerably When the moulds for the vertical layout is produced on a DISAMATIC that produces 350 moulds an hour the total energy saved per hour for both melting and heat treatment becomes 2,000 kWh and per eight hour work day 16,000 kWh. Seen in this perspective the potential for saving energy in the foundries is substantial. Furthermore the experiments where ductile iron valve housings was cast also proved that it is possible to lower the pouring temperature from 1,400℃ to 1,300℃ without the risk of cold runs. This is possible due to a high flow rate during mould filling in combination with low velocities due to the use of fan gates. All of this has also been investigated in experiments using glass plate fronted moulds.
基金funded by the Department of Science and Technology,Government of India(File No.SR/S3/MERC/0123/2009 dated 28.02.2011& Diary No.100/IFD/12365/2010-11 dated 28.02.2011)
文摘This work is concerned with the hydraulics and f low characterization in a pressurized,horizontal gating system with multiple ingates attached to a plate mold,using transparent water models.Runners with two different aspect ratios(w/h=0.5 and 2)and four different types of ingates(rectangular,convergent,divergent and venturi)were examined for their influence on flow behavior.Flow behavior was visualized using a high speed camera capable of capturing images up to 10,000 frames per second.Real time experimentation with a few runner–ingate combinations were carried out to validate the usefulness of water models in predicting the f illing behavior.Comparison of the approaches provided useful insights into the filling behavior in critical sections of the flow passages as well as the utility of water models towards understanding of the f illing behavior during real time casting.
基金supported by the Major Project of NSFC(51690161)the Student Innovation Program Major Project of Northeastern University(ZD1708)
文摘High pressure die casting(HPDC) is a kind of near net shape manufacturing method. However, air entrapment in HPDC parts has serious effects upon the casting quality. In order to reduce the air entrapment defects in a AlSi10 MnMg alloy thin-wall longitudinal load-bearing beam produced by HPDC, different gating systems were designed and simulated by software Flow-3D to evaluate the entrapped air. Simulation results showed that when the beam is produced by the original designed gating system with a middle ingate, there exist obvious air entrapments in the critical area; the volume of air entrapment was reduced by replacing the middle ingate to an overflow well, and the filling of molten metal became more stable. When the middle ingate was removed for further improvement, the volume of air entrapment was decreased drastically. The parts with glossy surface and good microstructure have been successfully produced by using the final optimized gating system based on simulation results.
基金financially supported by the National Key Research and Development Program of China (2022YFB3706802)。
文摘Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%.
基金funded by“the Fanying Special Program of the National Natural Science Foundation of China,grant number 62341307”“the Scientific research project of Jiangxi Provincial Department of Education,grant number GJJ200839”“theDoctoral startup fund of JiangxiUniversity of Technology,grant number 205200100402”.
文摘In multi-modal emotion recognition,excessive reliance on historical context often impedes the detection of emotional shifts,while modality heterogeneity and unimodal noise limit recognition performance.Existing methods struggle to dynamically adjust cross-modal complementary strength to optimize fusion quality and lack effective mechanisms to model the dynamic evolution of emotions.To address these issues,we propose a multi-level dynamic gating and emotion transfer framework for multi-modal emotion recognition.A dynamic gating mechanism is applied across unimodal encoding,cross-modal alignment,and emotion transfer modeling,substantially improving noise robustness and feature alignment.First,we construct a unimodal encoder based on gated recurrent units and feature-selection gating to suppress intra-modal noise and enhance contextual representation.Second,we design a gated-attention crossmodal encoder that dynamically calibrates the complementary contributions of visual and audio modalities to the dominant textual features and eliminates redundant information.Finally,we introduce a gated enhanced emotion transfer module that explicitly models the temporal dependence of emotional evolution in dialogues via transfer gating and optimizes continuity modeling with a comparative learning loss.Experimental results demonstrate that the proposed method outperforms state-of-the-art models on the public MELD and IEMOCAP datasets.
基金supported by the Natural Science Foundation of Guangdong Province,China (No.2025A1515011654)the National Natural Science Foundation of China (No.22090053)+3 种基金the Fundamental Research Funds for National Universities,China University of Geosciences (Wuhan)support from the program of China Scholarships Council (No.202406410155)Young Elite Scientists Sponsorship Program by CAST-Doctoral Student Special Plansupport from the S&T Special Program of Huzhou (No.2024GZ07)。
文摘Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.
基金supported by the National Natural Science Foundation of China(52025132,52300138,21621091,22021001,and 22121001)the National Postdoctoral Program for Innovative Talents(BX20230198)+4 种基金the China Postdoctoral Science Foundation(2023M732945)the Higher Education Discipline Innovation Project(B17027,B16029)the Natural Science Foundation of Fujian Province of China(2022J02059,2023J05012)the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)(RD2022070601)the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘Microbubbles have attracted considerable attention due to their distinctive properties,such as large surface area,inherent selfcompression,and exceptional mass transfer efficiency.These features render microbubbles valuable across a diverse range of industries,such as water treatment,mineral flotation,and the food industry.While several methods for microbubble generation exist,the gas–liquid membrane dispersion technique emerges as a reproducible and efficient alternative.Nevertheless,conventional approaches struggle to achieve active in situ control of bubble generation.In this study,we introduce an electrostatically responsive liquid gating system(ERLGS)designed for the active management of microbubble production.Utilizing electric fields and anionic surfactants,our system showcases the capability to dynamically regulate bubble size by manipulating the solid–liquid adsorption.Experiments confirm that this active control relies on the electrostatic adsorption and desorption of anionic surfactants,thereby regulating the interactions among the solid–liquid–gas interfaces.Our research elucidates the ERLGS's ability of precisely controlling the generation of bubbles in situ,enabling nearly one-order-of-magnitude change in bubble size,underscoring its applicability in various fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174435,12034020,and 92250303)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-091)the National Key R&D Program of China(Grant No.2022YFA1604200).
文摘Attosecond light pulses have revolutionized the study of electron dynamics in materials by enabling the observation of ultrafast processes with unprecedented attosecond temporal resolution.They are primarily generated through the process of high-order harmonic generation.This paper presents a comprehensive setup for attosecond pulse generation and measurement.Using a 900 nm,7 mJ,and 7 fs femtosecond laser with stabilized carrier-envelope phase,we employ polarization gating to generate a near single-cycle,linearly polarized pulse that interacts with neon gas to produce a broadband extreme-ultraviolet continuum with a cutoff photon energy of∼120 eV.The temporal and spectral characteristics of the generated single attosecond pulses are measured using an attosecond streak camera,and the pulse duration is determined to be 59 as through the frequency-resolved optical gating for complete reconstruction of attosecond bursts retrieval algorithm.As part of the Synergetic Extreme Condition User Facility,this setup will facilitate ultrafast research in transient absorption and photoelectron spectroscopy,providing global users with a powerful tool for studying electron dynamics in various materials.
基金financially supported by Natural Science Foundation of Shandong Province(Nos.ZR2022QB061,2022KJ181)National Key R&D Program of China(No.2023YFD1700903)。
文摘The development of multi-stimuli-responsive luminescent system to address emerging demands is essential in anti-counterfeiting field.Herein,a photoswitchable system was reported,which was constructed from photoacid sulfonato-merocyanine(MEH-D)serving as H+donor and diarylethene derivative(DAEA1)as acceptor.After capturing 2 equiv.HCl,the obtained fluorescent molecule DAE-A1-H showed solvatochromic property.Further on,benefiting from that MEH-D released protons and became a ring-closed isomer spiropyran(SP-D)under 440 nm irradiation,DAE-A1 was protonated,turning on fluorescence effect was realized in DAE-A1/MEH-D.In dark,a photo-activated reversible process was realized with SPD changed to MEH-D in situ system.In addition,the OF-DAE-A1-H/SP-D could efficiently and reversibly switch on/off its luminescence upon irradiation by UV–vis light.Significantly,the multi-stimuli-responsive system was successfully applied in logic gate and fluorescence ink,making it an efficient strategy for information encryption and decryption with higher security requirements.
基金funded by the Deanship of Scientific Research(DSR)at King Abdulaziz University Jeddah,under grant no.(GPIP:1168-611-2024)The authors acknowledge the DSR for financial and technical support.
文摘QR codes are widely used in applications such as information sharing,advertising,and digital payments.However,their growing adoption has made them attractive targets for malicious activities,including malware distribution and phishing attacks.Traditional detection approaches rely on URL analysis or image-based feature extraction,whichmay introduce significant computational overhead and limit real-time applicability,and their performance often depends on the quality of extracted features.Previous studies in malicious detection do not fully focus on QR code securitywhen combining convolutional neural networks(CNNs)with recurrent neural networks(RNNs).This research proposes a deep learning model that integrates AlexNet for feature extraction,principal component analysis(PCA)for dimensionality reduction,and RNNs to detect malicious activity in QR code images.The proposed model achieves both efficiency and accuracy by transforming image data into a compact one-dimensional sequence.Experimental results,including five-fold cross-validation,demonstrate that the model using gated recurrent units(GRU)achieved an accuracy of 99.81%on the first dataset and 99.59%in the second dataset with a computation time of only 7.433 ms per sample.A real-time prototype was also developed to demonstrate deployment feasibility.These results highlight the potential of the proposed approach for practical,real-time QR code threat detection.
文摘We investigate the impact of coupling on the reliability of the logic system as well as the logical stochastic resonance （LSR） phenomenon in the coupled logic gates system. It is found that compared with single logic gate, the coupled system could yield reliable logic outputs in a much wider noise region, which means coupling can obviously improve the reliability of the logic system and thus enhance the LSR effect. Moreover, we find that the enhancement is larger for larger system size, whereas for large enough size the enhancement seems to be saturated. Finally, we also examine the effect of coupling strength, it can be observed that the noise region where reliable logic outputs can be obtained evolves non-monotonically as the coupling strength increases, displaying a resonance-like effect.
基金supported by the National Natural Science Foundation of China(22475240,22090061,22488101)the State Key Laboratory of Catalysis(2024SKL-A-010)。
文摘The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molecular sieving emerges as the most promising approach,but it will be significantly compromised at high temperatures due to the significant thermal motion.Here,we report a thermally robust zinc-based metal-organic framework(MOF)that can be synthesized on sub-kilogram scale and achieve exceptional C_(3)H_(6)/C_(3)H_(8) separation performances across a broad temperature range(298–353 K).Unlike conventional MOFs suffering from thermal lattice expansion to give poorer selectivity,this new MOF gives the adsorption capacity of C_(3)H_(6)essentially unchanged and that of C_(3)H_(8) negligible at elevated temperatures,outperforming most state-of-the-art adsorbents,in virtue of multiple hydrogen bonds at the aperture.Column breakthrough experiments confirmed the excellent separation capability,and showed no performance degradation over multi-round adsorption-desorption cycles at 353 K.This study addresses the critical challenge of the trade-off between temperature and selectivity in adsorptive separation,which offers new insights into the design of porous structures for highly effective separation at high temperatures.
基金supported by the NationalNatural Science Foundation of China(U2004163)Key Research and Development Program of Henan Province(No.251111211200).
文摘In multi-domain neural machine translation tasks,the disparity in data distribution between domains poses significant challenges in distinguishing domain features and sharing parameters across domains.This paper proposes a Transformer-based multi-domain-aware mixture of experts model.To address the problem of domain feature differentiation,a mixture of experts(MoE)is introduced into attention to enhance the domain perception ability of the model,thereby improving the domain feature differentiation.To address the trade-off between domain feature distinction and cross-domain parameter sharing,we propose a domain-aware mixture of experts(DMoE).A domain-aware gating mechanism is introduced within the MoE module,simultaneously activating all domain experts to effectively blend domain feature distinction and cross-domain parameter sharing.A loss balancing function is then added to dynamically adjust the impact of the loss function on the expert distribution,enabling fine-tuning of the expert activation distribution to achieve a balance between domains.Experimental results on multiple Chinese-to-English and English-to-French datasets demonstrate that our proposed method significantly outperforms baseline models in both BLEU,chrF,and COMET metrics,validating its effectiveness in multi-domain neural machine translation.Further analysis of the probability distribution of expert activations shows that our method achieves remarkable results in both domain differentiation and cross-domain parameter sharing.
基金financially supported by the National Natural Science Foundation of China (NSFC,Nos.22134005 and 22074124)Chongqing Talents Program for Outstanding Scientists (No.cstc2021ycjh-bgzxm0178)+1 种基金Natural Science Foundation of Chongqing (No.CSTB2022NSCQ-MSX0521)the Chongqing Graduate Student Scientific Research Innovation Project (No.CYB21119)。
文摘Regulation of apoptosis represents a key parameter in all living organisms.In this paper,an input-induced logic-gated modular nanocalculator is designed to regulate cancer cell apoptosis by programmatically combining and connecting logic gate modules with different functions.Via rational design of the various logic gate modules of the nanocalculator,different apoptosis related operations including cancer cell targeting,apoptosis induction,and apoptosis monitoring could be performed.Importantly,each of these logic gate modules could independently perform apoptosis related YES logic operations when ran separately.After combining each YES logic gate module into a logic circuit and connecting it to the GO scaffold to construct a logic-gated nanocalculator,the input-induced logic-gated modular nanocalculator could selectively enter cancer cells and control the drug release to logically apoptosis(output),by performing AND logic gate operations when inputs(nucleolin and H^(+)) were included at the same time.Moreover,evidence suggests that these efficient logical calculations proceed in cancer cell apoptosis regulation without the general limiations of lithography in nanotechnology.As such,this work provides a new vision for the construction of a logic-gated modular nanocalculator with logical calculation proficiency potentially useful in cancer therapy and the regulation of life.
