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
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
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
Unmanned aerial vehicles(UAVs)have been widely used in military,medical,wireless communications,aerial surveillance,etc.One key topic involving UAVs is pose estimation in autonomous navigation.A standard procedure for...Unmanned aerial vehicles(UAVs)have been widely used in military,medical,wireless communications,aerial surveillance,etc.One key topic involving UAVs is pose estimation in autonomous navigation.A standard procedure for this process is to combine inertial navigation system sensor information with the global navigation satellite system(GNSS)signal.However,some factors can interfere with the GNSS signal,such as ionospheric scintillation,jamming,or spoofing.One alternative method to avoid using the GNSS signal is to apply an image processing approach by matching UAV images with georeferenced images.But a high effort is required for image edge extraction.Here a support vector regression(SVR)model is proposed to reduce this computational load and processing time.The dynamic partial reconfiguration(DPR)of part of the SVR datapath is implemented to accelerate the process,reduce the area,and analyze its granularity by increasing the grain size of the reconfigurable region.Results show that the implementation in hardware is 68 times faster than that in software.This architecture with DPR also facilitates the low power consumption of 4 mW,leading to a reduction of 57%than that without DPR.This is also the lowest power consumption in current machine learning hardware implementations.Besides,the circuitry area is 41 times smaller.SVR with Gaussian kernel shows a success rate of 99.18%and minimum square error of 0.0146 for testing with the planning trajectory.This system is useful for adaptive applications where the user/designer can modify/reconfigure the hardware layout during its application,thus contributing to lower power consumption,smaller hardware area,and shorter execution time.展开更多
Photonic hyper-parallel quantum gates play a critical role in high-capacity quantum communication and fast quantum computing.Here,based on photon scattering in onedimensional(1D)waveguides,we present some heralded sch...Photonic hyper-parallel quantum gates play a critical role in high-capacity quantum communication and fast quantum computing.Here,based on photon scattering in onedimensional(1D)waveguides,we present some heralded schemes for constructing four-qubit hyper-controlled-not(hyper-CNOT)gates in two-photon systems.The qubits are encoded on both the polarization and spatial-mode degrees of freedoms(DOFs)of the photons,which can simplify the quantum circuit and reduce the quantum resource consumption.In our schemes,the faulty scattering events between photons and emitters caused by system imperfections can be filtered out and discarded.That is,our protocols for hyper-CNOT gates work in a heralded way.Our calculations show that,with great progress in the emitter-waveguide systems,our photonic hyper-CNOT gates may be experimentally feasible.展开更多
Traditional e-commerce recommendation systems often struggle with dynamic user preferences and a vast array of products,leading to suboptimal user experiences.To address this,our study presents a Personalized Adaptive...Traditional e-commerce recommendation systems often struggle with dynamic user preferences and a vast array of products,leading to suboptimal user experiences.To address this,our study presents a Personalized Adaptive Multi-Product Recommendation System(PAMR)leveraging transfer learning and Bi-GRU(Bidirectional Gated Recurrent Units).Using a large dataset of user reviews from Amazon and Flipkart,we employ transfer learning with pre-trained models(AlexNet,GoogleNet,ResNet-50)to extract high-level attributes from product data,ensuring effective feature representation even with limited data.Bi-GRU captures both spatial and sequential dependencies in user-item interactions.The innovation of this study lies in the innovative feature fusion technique that combines the strengths of multiple transfer learning models,and the integration of an attention mechanism within the Bi-GRU framework to prioritize relevant features.Our approach addresses the classic recommendation systems that often face challenges such as cold start along with data sparsity difficulties,by utilizing robust user and item representations.The model demonstrated an accuracy of up to 96.9%,with precision and an F1-score of 96.2%and 96.97%,respectively,on the Amazon dataset,significantly outperforming the baselines and marking a considerable advancement over traditional configurations.This study highlights the effectiveness of combining transfer learning with Bi-GRU for scalable and adaptive recommendation systems,providing a versatile solution for real-world applications.展开更多
In recent years,machine learning(ML)and deep learning(DL)have significantly advanced intrusion detection systems,effectively addressing potential malicious attacks across networks.This paper introduces a robust method...In recent years,machine learning(ML)and deep learning(DL)have significantly advanced intrusion detection systems,effectively addressing potential malicious attacks across networks.This paper introduces a robust method for detecting and categorizing attacks within the Internet of Things(IoT)environment,leveraging the NSL-KDD dataset.To achieve high accuracy,the authors used the feature extraction technique in combination with an autoencoder,integrated with a gated recurrent unit(GRU).Therefore,the accurate features are selected by using the cuckoo search algorithm integrated particle swarm optimization(PSO),and PSO has been employed for training the features.The final classification of features has been carried out by using the proposed RF-GNB random forest with the Gaussian Naïve Bayes classifier.The proposed model has been evaluated and its performance is verified with some of the standard metrics such as precision,accuracy rate,recall F1-score,etc.,and has been compared with different existing models.The generated results that detected approximately 99.87%of intrusions within the IoT environments,demonstrated the high performance of the proposed method.These results affirmed the efficacy of the proposed method in increasing the accuracy of intrusion detection within IoT network systems.展开更多
Cyclic nucleotide-gated ion channels （CNGs） are distributed most widely in the neuronal cell. Great progress has been made in molecular mechanisms of CNG channel gating in the recent years. Results of many experimen...Cyclic nucleotide-gated ion channels （CNGs） are distributed most widely in the neuronal cell. Great progress has been made in molecular mechanisms of CNG channel gating in the recent years. Results of many experiments have indicated that the stoichiometry and assembly of CNG channels affect their property and gating. Experiments of CNG mutants and analyses of cys- teine accessibilities show that cyclic nucleotide-binding domains （CNBD） bind cyclic nucleotides and subsequently conformational changes occurred followed by the concerted or cooperative conformational change of all four subunits during CNG gating. In order to provide theoretical assistances for further investigation on CNG channels, especially regarding the disease pathogenesis of ion channels, this paper reviews the latest progress on mechanisms of CNG channels, functions of subunits, processes of subunit assembly, and conformational changes of subunit regions during gating.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
Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive ...Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate response.However,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of time.Herein we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor application.We systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 nW.The sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on it.Moreover,there was almost no performance loss for the device as left in the air for two months.展开更多
A coordination polymer{[Cd(H_(2)dpa)(bpy)]·3H_(2)O}_(n)(Cd-CP)was designed and hydrothermal synthesized based on 4-(2,4-dicarboxyphenoxy)phthalic acid(H_(4)dpa),2,2'-bipyridine(bpy)and Cd(NO_(3))_(2)·4H_...A coordination polymer{[Cd(H_(2)dpa)(bpy)]·3H_(2)O}_(n)(Cd-CP)was designed and hydrothermal synthesized based on 4-(2,4-dicarboxyphenoxy)phthalic acid(H_(4)dpa),2,2'-bipyridine(bpy)and Cd(NO_(3))_(2)·4H_(2)O.The structure was characterized by single-crystal X-ray diffraction,powder X-ray diffraction,elemental analysis,and infrared spectroscopy.Cd-CP belongs to the monoclinic crystal system with the P2_1/c space group and performs in a 1D double-chain structure.The adjacent double chains further form a 3D supramolecular network structure through hydrogen bonding.Thermogravimetric analysis shows that Cd-CP has good thermal stability.Fluorescence analysis showed that Cd-CP had good choosing selectively and was sensitive to metal ions(Fe^(3+)and Zn^(2+)),2,4,6-trinitrophenylhydrazine(TRI),and pyrimethanil(Pth).Interestingly,when Cd-CP was used for fluorescence detection of metal ions,it was found to have a fluorescence quenching effect on Fe^(3+)but had an obvious enhancement effect on Zn^(2+).Therefore,we designed an“on-off-on”logic gate.In addition,the mechanism of fluorescence sensing has been deeply explored.CCDC:2258625.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financially supported by the National Council for Scientific and Technological Development(CNPq,Brazil),Swedish-Brazilian Research and Innovation Centre(CISB),and Saab AB under Grant No.CNPq:200053/2022-1the National Council for Scientific and Technological Development(CNPq,Brazil)under Grants No.CNPq:312924/2017-8 and No.CNPq:314660/2020-8.
文摘Unmanned aerial vehicles(UAVs)have been widely used in military,medical,wireless communications,aerial surveillance,etc.One key topic involving UAVs is pose estimation in autonomous navigation.A standard procedure for this process is to combine inertial navigation system sensor information with the global navigation satellite system(GNSS)signal.However,some factors can interfere with the GNSS signal,such as ionospheric scintillation,jamming,or spoofing.One alternative method to avoid using the GNSS signal is to apply an image processing approach by matching UAV images with georeferenced images.But a high effort is required for image edge extraction.Here a support vector regression(SVR)model is proposed to reduce this computational load and processing time.The dynamic partial reconfiguration(DPR)of part of the SVR datapath is implemented to accelerate the process,reduce the area,and analyze its granularity by increasing the grain size of the reconfigurable region.Results show that the implementation in hardware is 68 times faster than that in software.This architecture with DPR also facilitates the low power consumption of 4 mW,leading to a reduction of 57%than that without DPR.This is also the lowest power consumption in current machine learning hardware implementations.Besides,the circuitry area is 41 times smaller.SVR with Gaussian kernel shows a success rate of 99.18%and minimum square error of 0.0146 for testing with the planning trajectory.This system is useful for adaptive applications where the user/designer can modify/reconfigure the hardware layout during its application,thus contributing to lower power consumption,smaller hardware area,and shorter execution time.
基金supported by the Tianjin Natural Science Foundation under Grant No.23JCQNJC00560the Natural Science Funds of Tianjin Normal University under Grant No.YJRC202421+2 种基金the National Natural Science Foundation of China under Grants Nos.12004281 and 62371038the Scientific Research the Natural Science Basic Research Program of Shaanxi under Grant No.2023-JC-QN-0092the Program Funded by Education Department of Shaanxi Provincial Government under Grant No.23JK0705。
文摘Photonic hyper-parallel quantum gates play a critical role in high-capacity quantum communication and fast quantum computing.Here,based on photon scattering in onedimensional(1D)waveguides,we present some heralded schemes for constructing four-qubit hyper-controlled-not(hyper-CNOT)gates in two-photon systems.The qubits are encoded on both the polarization and spatial-mode degrees of freedoms(DOFs)of the photons,which can simplify the quantum circuit and reduce the quantum resource consumption.In our schemes,the faulty scattering events between photons and emitters caused by system imperfections can be filtered out and discarded.That is,our protocols for hyper-CNOT gates work in a heralded way.Our calculations show that,with great progress in the emitter-waveguide systems,our photonic hyper-CNOT gates may be experimentally feasible.
文摘Traditional e-commerce recommendation systems often struggle with dynamic user preferences and a vast array of products,leading to suboptimal user experiences.To address this,our study presents a Personalized Adaptive Multi-Product Recommendation System(PAMR)leveraging transfer learning and Bi-GRU(Bidirectional Gated Recurrent Units).Using a large dataset of user reviews from Amazon and Flipkart,we employ transfer learning with pre-trained models(AlexNet,GoogleNet,ResNet-50)to extract high-level attributes from product data,ensuring effective feature representation even with limited data.Bi-GRU captures both spatial and sequential dependencies in user-item interactions.The innovation of this study lies in the innovative feature fusion technique that combines the strengths of multiple transfer learning models,and the integration of an attention mechanism within the Bi-GRU framework to prioritize relevant features.Our approach addresses the classic recommendation systems that often face challenges such as cold start along with data sparsity difficulties,by utilizing robust user and item representations.The model demonstrated an accuracy of up to 96.9%,with precision and an F1-score of 96.2%and 96.97%,respectively,on the Amazon dataset,significantly outperforming the baselines and marking a considerable advancement over traditional configurations.This study highlights the effectiveness of combining transfer learning with Bi-GRU for scalable and adaptive recommendation systems,providing a versatile solution for real-world applications.
基金the Deanship of Scientific Research at Shaqra University for funding this research work through the project number(SU-ANN-2023051).
文摘In recent years,machine learning(ML)and deep learning(DL)have significantly advanced intrusion detection systems,effectively addressing potential malicious attacks across networks.This paper introduces a robust method for detecting and categorizing attacks within the Internet of Things(IoT)environment,leveraging the NSL-KDD dataset.To achieve high accuracy,the authors used the feature extraction technique in combination with an autoencoder,integrated with a gated recurrent unit(GRU).Therefore,the accurate features are selected by using the cuckoo search algorithm integrated particle swarm optimization(PSO),and PSO has been employed for training the features.The final classification of features has been carried out by using the proposed RF-GNB random forest with the Gaussian Naïve Bayes classifier.The proposed model has been evaluated and its performance is verified with some of the standard metrics such as precision,accuracy rate,recall F1-score,etc.,and has been compared with different existing models.The generated results that detected approximately 99.87%of intrusions within the IoT environments,demonstrated the high performance of the proposed method.These results affirmed the efficacy of the proposed method in increasing the accuracy of intrusion detection within IoT network systems.
基金This work was supported by the Provincial Key Projects for Scientifical and Technological Research of Zhejiang Province (No. 2006C12058)National Natural Science Foundation of China (No. 30571335) and a Grant-in-Aid for Innovative Training of Doctoral Students in JIangsu Province,China.
文摘Cyclic nucleotide-gated ion channels （CNGs） are distributed most widely in the neuronal cell. Great progress has been made in molecular mechanisms of CNG channel gating in the recent years. Results of many experiments have indicated that the stoichiometry and assembly of CNG channels affect their property and gating. Experiments of CNG mutants and analyses of cys- teine accessibilities show that cyclic nucleotide-binding domains （CNBD） bind cyclic nucleotides and subsequently conformational changes occurred followed by the concerted or cooperative conformational change of all four subunits during CNG gating. In order to provide theoretical assistances for further investigation on CNG channels, especially regarding the disease pathogenesis of ion channels, this paper reviews the latest progress on mechanisms of CNG channels, functions of subunits, processes of subunit assembly, and conformational changes of subunit regions during gating.
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financially supported by the National Natural Science Foundation of China(Nos.52272160,U2330112,and 52002254)Sichuan Science and Technology Foundation(Nos.2020YJ0262,2021YFH0127,2022YFH0083,2022YFSY0045,and 2023YFSY0002)+1 种基金the Chunhui Plan of Ministry of Education,Fundamental Research Funds for the Central Universities,China(No.YJ201893)the Foundation of Key Laboratory of Lidar and Device,Sichuan Province,China(No.LLD2023-006)。
文摘Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other fields.Two-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate response.However,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of time.Herein we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor application.We systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 nW.The sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on it.Moreover,there was almost no performance loss for the device as left in the air for two months.
文摘A coordination polymer{[Cd(H_(2)dpa)(bpy)]·3H_(2)O}_(n)(Cd-CP)was designed and hydrothermal synthesized based on 4-(2,4-dicarboxyphenoxy)phthalic acid(H_(4)dpa),2,2'-bipyridine(bpy)and Cd(NO_(3))_(2)·4H_(2)O.The structure was characterized by single-crystal X-ray diffraction,powder X-ray diffraction,elemental analysis,and infrared spectroscopy.Cd-CP belongs to the monoclinic crystal system with the P2_1/c space group and performs in a 1D double-chain structure.The adjacent double chains further form a 3D supramolecular network structure through hydrogen bonding.Thermogravimetric analysis shows that Cd-CP has good thermal stability.Fluorescence analysis showed that Cd-CP had good choosing selectively and was sensitive to metal ions(Fe^(3+)and Zn^(2+)),2,4,6-trinitrophenylhydrazine(TRI),and pyrimethanil(Pth).Interestingly,when Cd-CP was used for fluorescence detection of metal ions,it was found to have a fluorescence quenching effect on Fe^(3+)but had an obvious enhancement effect on Zn^(2+).Therefore,we designed an“on-off-on”logic gate.In addition,the mechanism of fluorescence sensing has been deeply explored.CCDC:2258625.
