The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical m...The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical model height.The Taguchi method was employed to establish the correlations between process parameter combinations and multi-objective characterization of metal deposition morphology(height error and roughness).Results show that using the signal-to-noise ratio and grey relational analysis,the optimal parameter combination for multi-layer and multi-pass deposition is determined as follows:laser power of 800 W,powder feeding rate of 0.3 r/min,step distance of 1.6 mm,and scanning speed of 20 mm/s.Subsequently,a Genetic Bayesian-back propagation(GB-BP)network is constructed to predict multi-objective responses.Compared with the traditional back propagation network,the GB-back propagation network improves the prediction accuracy of height error and surface roughness by 43.14%and 71.43%,respectively.This network can accurately predict the multi-objective characterization of morphological quality of multi-layer and multi-pass metal deposited parts.展开更多
Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.L...Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.Lipid and free fatty acid contents in grains correlate positively with cooking and eating quality of rice.This study examined Yangdao 6(YD6,a conventional taste indica inbred)and Nanjing 9108(NJ9108,a superior taste japonica inbred)cultivated under conventional irrigation(CI),alternate wetting and moderate drying irrigation(AWMD),and alternate wetting and severe drying irrigation(AWSD)from 10 days after transplanting to maturity.The research investigated the relationship between lipid and free fatty acid biosynthesis in grains and the cooking and eating quality of rice.Compared to CI treatment,AWMD significantly enhanced the contents of lipid,total free fatty acids(TFFAs),free unsaturated fatty acids(FUFAs),linoleic acid,and oleic acid in milled rice by increasing activities of enzymes associated with lipid synthesis,while AWSD produced opposite effects.Correlation analysis revealed that elevated levels of lipid,TFFAs,FUFAs,linoleic acid,and oleic acid contribute to improved rice cooking and eating quality.The findings demonstrate that AWMD enhances cooking and eating quality of milled rice through optimization of lipid and fatty acid synthesis in rice grains.展开更多
At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-laye...At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool head.The material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys.The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center area.Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped zone.The tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition sample.It is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area.The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.展开更多
The huge impact kinetic energy cannot be quickly dissipated by the energy-absorbing structure and transferred to the other vehicle through the car body structure,which will cause structural damage and threaten the liv...The huge impact kinetic energy cannot be quickly dissipated by the energy-absorbing structure and transferred to the other vehicle through the car body structure,which will cause structural damage and threaten the lives of the occupants.Therefore,it is necessary to understand the laws of energy conversion,dissipation and transfer during train collisions.This study proposes a multi-layer progressive analysis method of energy flow during train collisions,considering the characteristics of the train.In this method,the train collision system is divided into conversion,dissipation,and transfer layers from the perspective of the train,collision interface,and car body structure to analyze the energy conversion,dissipation and transfer characteristics.Taking the collision process of a rail train as an example,a train collision energy transfer path analysis model was established based on power flow theory.The results show that when the maximum mean acceleration of the vehicle meets the standard requirements,the jerk may exceed the allowable limit of the human body,and there is a risk of injury to the occupants of a secondary collision.The decay rate of the collision energy along the direction of train operation reaches 79%.As the collision progresses,the collision energy gradually converges in the structure with holes,and the structure deforms when the gathered energy is greater than the maximum energy the structure can withstand.The proposed method helps to understand the train collision energy flow law and provides theoretical support for the train crashworthiness design in the future.展开更多
The growing incidence of cyberattacks necessitates a robust and effective Intrusion Detection Systems(IDS)for enhanced network security.While conventional IDSs can be unsuitable for detecting different and emerging at...The growing incidence of cyberattacks necessitates a robust and effective Intrusion Detection Systems(IDS)for enhanced network security.While conventional IDSs can be unsuitable for detecting different and emerging attacks,there is a demand for better techniques to improve detection reliability.This study introduces a new method,the Deep Adaptive Multi-Layer Attention Network(DAMLAN),to boost the result of intrusion detection on network data.Due to its multi-scale attention mechanisms and graph features,DAMLAN aims to address both known and unknown intrusions.The real-world NSL-KDD dataset,a popular choice among IDS researchers,is used to assess the proposed model.There are 67,343 normal samples and 58,630 intrusion attacks in the training set,12,833 normal samples,and 9711 intrusion attacks in the test set.Thus,the proposed DAMLAN method is more effective than the standard models due to the consideration of patterns by the attention layers.The experimental performance of the proposed model demonstrates that it achieves 99.26%training accuracy and 90.68%testing accuracy,with precision reaching 98.54%on the training set and 96.64%on the testing set.The recall and F1 scores again support the model with training set values of 99.90%and 99.21%and testing set values of 86.65%and 91.37%.These results provide a strong basis for the claims made regarding the model’s potential to identify intrusion attacks and affirm its relatively strong overall performance,irrespective of type.Future work would employ more attempts to extend the scalability and applicability of DAMLAN for real-time use in intrusion detection systems.展开更多
In practical engineering construction,multi-layered barriers containing geomembranes are extensively applied to retard the migration of pollutants.However,the associated analytical theory on pollutants diffusion still...In practical engineering construction,multi-layered barriers containing geomembranes are extensively applied to retard the migration of pollutants.However,the associated analytical theory on pollutants diffusion still needs to be further improved.In this work,general analytical solutions are derived for one-dimensional diffusion of degradable organic contaminant(DOC)in the multi-layered media containing geomembranes under a time-varying concentration boundary condition,where the variable substitution and separated variable approaches are employed.These analytical solutions with clear expressions can be used not only to study the diffusion behaviors of DOC in bottom and vertical composite barrier systems,but also to verify other complex numerical models.The proposed general analytical solutions are then fully validated via three comparative analyses,including comparisons with the experimental measurements,an existing analytical solution,and a finite-difference solution.Ultimately,the influences of different factors on the composite cutoff wall’s(CCW,which consists of two soil-bentonite layers and a geomembrane)service performance are investigated through a composite vertical barrier system as the application example.The findings obtained from this investigation can provide scientific guidance for the barrier performance evaluation and the engineering design of CCWs.This application example also exhibits the necessity and effectiveness of the developed analytical solutions.展开更多
"Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also t..."Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also the cooking techniques,ingredients selection,seasoning skills and dish innovation of Sichuan cuisine.Doing a good job in the teaching of"Sichuan Cuisine Cooking Skills"is of great significance to the cultivation and reserve of culinary professionals in China,and also has an important impact on students'employment competitiveness.Under the background of"new engineering education",the course reform of"Sichuan Cuisine Cooking Skills"was carried out in terms of the construction of teaching staff,teaching methods,students'participation degree and the innovation of course content,and specific reform suggestions were put forward,hoping to effectively promote the sustainable development of"Sichuan Cuisine Cooking Skills"and effectively improve the teaching quality.展开更多
Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological c...Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological conditions.In this study,we conducted experiments using four different sowing dates,the conventional sowing date 1(CS1),CS2(10 d later than CS1),DS1(30 d later than CS1),and DS2(30 d later than CS2),and three rice varieties,i.e.,Yixiangyou 2115,Fyou 498,and Chuanyou 6203.This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the infuence of DS on the pasting properties of rice,which are a proxy for the eating and cooking quality(ECQ).In DS1 and DS2,the rice had a signifcantly greater amylose content(AC)but a lower protein content(PC),peak viscosity(PKV),cool paste viscosity(CPV),and hot paste viscosity(HPV)than in CS1 and CS2.Moreover,except for CS2 and DS1 in 2018,DS1 and DS2 led to 2.15-11.19%reductions in breakdown viscosity(BDV)and 23.46-108.47%increases in setback viscosity(SBV).However,the infuence of DS on rice pasting properties varied by study site and rice variety.In 2019,DS1 and DS2 led to BDV reductions of 2.35-9.33,2.61-8.61,10.03-17.78,and 2.06-8.93%,and SBV increases of 2.32-60.93,63.74-144.24,55.46-91.63,and-8.28-65.37%at the Dayi,Anzhou,Nanbu,and Shehong(except for SBV in CS2 and DS1)sites,respectively.DS resulted in greater reductions in PKV,HPV,CPV,and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.The correlation analysis indicated that PKV and HPV were signifcantly and positively related to the mean,maximum,and minimum temperatures after heading.These temperatures must be greater than 25.9,31.2,and 22.3℃,respectively,to increase the relative BDV and reduce the relative SBV of rice,thereby enhancing ECQ.In conclusion,DS might contribute to a signifcant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice.展开更多
Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanism...Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanisms in these multi-layer composites is essential,as it offers intuitive insights into parametric influences and facilitates enhanced structural performance.This paper employs an improved transfer matrix method to address the limitations of existing theoretical approaches for analyzing multi-layer composite structures.By establishing a twodimensional composite pavement model,it investigates load transfer characteristics and validates the accuracy through finite element simulation.The proposed method offers a straightforward analytical approach for examining internal interactions between structural layers.Case studies indicate that the concrete surface layer is the main load-bearing layer for most vertical normal and shear stresses.The soil base layer reduces the overall mechanical response of the substructure,while horizontal actions increase the risk of interfacial slip and cracking.Structural optimization analysis demonstrates that increasing the thickness of the concrete surface layer,enhancing the thickness and stiffness of the soil base layer,or incorporating gradient layers can significantly mitigate these risks of interfacial slip and cracking.The findings of this study can guide the optimization design,parameter analysis,and damage prevention of multi-layer composite structures.展开更多
This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi...This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.展开更多
Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed ...Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed satellites,ground users now can be covered by multiple visible satellites,but also face complex handover issues with such massive high-mobility satellites in multi-layer.The end-to-end routing is also affected by the handover behavior.In this paper,we propose an intelligent handover strategy dedicated to multi-layer LEO mega-constellation networks.Firstly,an analytic model is utilized to rapidly estimate the end-to-end propagation latency as a key handover factor to construct a multi-objective optimization model.Subsequently,an intelligent handover strategy is proposed by employing the Dueling Double Deep Q Network(D3QN)-based deep reinforcement learning algorithm for single-layer constellations.Moreover,an optimal crosslayer handover scheme is proposed by predicting the latency-jitter and minimizing the cross-layer overhead.Simulation results demonstrate the superior performance of the proposed method in the multi-layer LEO mega-constellation,showcasing reductions of up to 8.2%and 59.5%in end-to-end latency and jitter respectively,when compared to the existing handover strategies.展开更多
Particulate levoglucosan is an important tracer for biomass burning emission in ambient air.However,recent studies question its reliability as a biomass burning tracer in Chinesemega cities due to important contributi...Particulate levoglucosan is an important tracer for biomass burning emission in ambient air.However,recent studies question its reliability as a biomass burning tracer in Chinesemega cities due to important contribution from potential non-biomass burning sources,such as cooking.To address this,we examined the dynamic variation and sources of levoglucosan using a chemical ionization mass spectrometer and other advanced instruments during Beijing’s summer of 2021.The average mass concentration of levoglucosan and its isomer(C_(6)H_(10)O_(5))was 0.025±0.014μg/m^(3),constituting 0.55%±0.32%of total organic carbon(OC)in this campaign.Despite cooking emissions contributing significantly to the organic aerosol(OA,20%),levoglucosan and its isomers correlated more strongly with biomass-burning related tracers(R>0.6),black carbon(R=0.72)and less so with cooking-related sources(R=0.3).This indicates that levoglucosan is primarily dominated by biomass-burning emissions rather than cooking in Beijing’s urban areas during summertime.The diurnal variation of levoglucosan concentrations highlighted the importance of daytime and nocturnal biomass burning emissions during polluted periods in Beijing.Using levoglucosan as a tracer to quantify the biomass burning OC(BBOC),we found good agreement on the time series of BBOC between the tracermethod and other independent source apportionmentmethod.This reaffirms the reliability of levoglucosan as a biomass burning tracer.Biomass burning contributed an average of 7%-8%to OC,highlighting its significant impact on Beijing’s summer air quality.Our study enhances understanding of biomass burning influences on ambient aerosol in typical urban areas.展开更多
Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the...Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the effects of textile structure,layering,and ply orientation on the stab resistance of multi-layer textiles.Three 3D warp interlock(3DWI)structures({f1},{f2},{f3})and a 2D woven fabric({f4}),all made of high-performance p-aramid yarns,were engineered and manufactured.Multi-layer specimens were prepared and subjected to drop-weight stabbing tests following HOSBD standards.Stabbing performance metrics,including Depth of Trauma(DoT),Depth of Penetration(DoP),and trauma deformation(Ymax,Xmax),were investigated and analyzed.Statistical analyses(Two-and One-Way ANOVA)indicated that fabric type and layer number significantly impacted DoP(P<0.05),while ply orientation significantly affected DoP(P<0.05)but not DoT(P>0.05).Further detailed analysis revealed that 2D woven fabrics exhibited greater trauma deformation than 3D WIF structures.Increasing the number of layers reduced both DoP and DoT across all fabric structures,with f3 demonstrating the best performance in multi-layer configurations.Aligned ply orientations also enhanced stab resistance,underscoring the importance of alignment in dissipating impact energy.展开更多
Objectives To characterize fine particulate matter(PM_(2.5))-bound polycyclic aromatic hydrocarbons(PAHs)emitted from different cooking fumes and their exposure routes and assess their health-associated impact to prov...Objectives To characterize fine particulate matter(PM_(2.5))-bound polycyclic aromatic hydrocarbons(PAHs)emitted from different cooking fumes and their exposure routes and assess their health-associated impact to provide a reference for health risk prevention from PAH exposure across different age and sex groups.Methods Sixteen PM_(2.5)-bound PAHs emitted from 11 cooking styles were analyzed using GC-MS/MS.The health hazards of these PAHs in the Handan City population(stratified by age and sex)were predicted using the incremental lifetime cancer risk(ILCR)model.The respiratory deposition doses(RDDs)of the PAHs in children and adults were calculated using the PM_(2.5)deposition rates in the upper airway,tracheobronchial,and alveolar regions.Results The total concentrations of PM_(2.5)-bound PAHs ranged from 61.10 to 403.80 ng/m3.Regardless of cooking styles,the ILCRtotal values for adults(1.23×10^(-6)to 3.70×10^(-6))and older adults(1.28×10^(-6)to 3.88×10^(-6))exceeded the acceptable limit of 1.00×10^(-6).With increasing age,the ILCRtotal value first declined and then increased,varying substantially among the population groups.Cancer risk exhibited particularly high sensitivity to short exposure to barbecue-derived PAHs under equivalent body weights.Furthermore,barbecue,Sichuan and Hunan cuisine,Chinese cuisine,and Chinese fast food were associated with higher RDDs for both adults and children.Conclusion ILCRtotal values exceeded the acceptable limit for both females and males of adults,with all cooking styles showing a potentially high cancer risk.Our findings serve as an important reference for refining regulatory strategies related to catering emissions and mitigating health risks associated with cooking styles.展开更多
Cooking fumes (CFs) are mixtures of many toxic components, such as aldehydes, heterocyclic amines, polycyclic aromatic hydrocarbons, fat aerosols and particulate matters. CFs exposure has been proven to be associate...Cooking fumes (CFs) are mixtures of many toxic components, such as aldehydes, heterocyclic amines, polycyclic aromatic hydrocarbons, fat aerosols and particulate matters. CFs exposure has been proven to be associated with many diseases. Lung cancer takes the leading place among the diseases being reported caused by CFs exposure. Molecular and biochemical studies have found that CFs exposure may lead to lung cancer by gene damage, formation of reactive oxygen species, blockage of related proteins’ function, and even cell death. However, reviews about the mechanisms of how CFs exposure leads to lung cancer are still lacking. Elucidation of the mechanisms of lung cancer caused by CFs exposure may provide a new insight into the prevention of lung cancer caused by CFs exposure, as well as laying the foundation for the toxicity study of CFs. In this minor review, the mechanisms of how CFs exposure leads to lung cancer were summarized and discussed.展开更多
PM 2.5 samples were collected by a three-stage cascade impactor at two kinds of Chinese restaurants to characterize fine organic particulate matter from Chinese cooking sources. Major individual organic compounds h...PM 2.5 samples were collected by a three-stage cascade impactor at two kinds of Chinese restaurants to characterize fine organic particulate matter from Chinese cooking sources. Major individual organic compounds have been quantified by GC/MS, including series of alkanes, n-alkanoic acids, n-alkanals, alkan-2-ones and PAHs. Alkanes and ketones make up a significant fraction of particle-phase organic compounds, ranging from C 11 to C 26, and C 9 to C 19, respectively. In addition, other organic compound classes have been identified, such as alkanols, esters, furans, lactones, amides, and nitriles. The mass concentrations of fine particles, alkanes, n-alkanoic acids and PAHs in air emitted from the Uigur style cooking are hundreds times higher than ambient PM 2.5in Beijing.展开更多
Cooking and nutrition qualities of grain are two of the most important aspects of rice quality. To understand the difference in cooking and nutrition qualities among the grains at different positions within a rice pan...Cooking and nutrition qualities of grain are two of the most important aspects of rice quality. To understand the difference in cooking and nutrition qualities among the grains at different positions within a rice panicle, the distributions of gel consistency (GC), amylose content (AC) and crude protein content (CPC) of grains in a panicle in association with different nitrogen levels (0, 120 and 240 k c/ha) were investigated by using two rice varieties, Yangdao 6 (indica) and Wuyujing 3 (japonica). In general, the grains at the basal part of a panicle had lower GC and higher AC than those at the upper or middle part of a panicle. The 1^st grain on the secondary branch with earlier flowering exhibited the highest GC, whereas the 2nd grain on the primary branch with later flowering showed the highest AC. For Yangdao 6, CPC in the grains on the primary branches was lower at the middle part of a panicle than at the upper or basal part of a panicle. For Wuyujing 3, there were no significant differences in CPCs in the grains among the upper, middle and basal parts of a panicle. GC in the grains was increased, whereas AC was reduced from zero nitrogen application (ON) to low amount of nitrogen application (LN), and the result was reversed from LN to medium amount of nitrogen application (MN). CPC was increased with the increase in the amount of nitrogen application.展开更多
Purple rice is a source of bioactive antioxidants for rice consumers. Loss of the major antioxidant compounds after a range of cooking processes was evaluated by measuring the changes in anthocyanin concentration (AT...Purple rice is a source of bioactive antioxidants for rice consumers. Loss of the major antioxidant compounds after a range of cooking processes was evaluated by measuring the changes in anthocyanin concentration (ATC) and antioxidant capacity (DPPH activity) of four non-glutinous and four glutinous genotypes. However, soaking in water prior to cooking generally decreased more ATC and antioxidant capacity in non-glutinous than in glutinous genotypes. Wet cooking (WC) and soaking before wet cooking (S-WC) led to lose almost all the ATC and antioxidant capacity with only slight variation between genotypes. In the glutinous genotype Pieisu, which had the highest raw rice ATC, ATC remained the highest when cooked by the WC method. By contrast, almost no ATC remained after WC and S-WC in the low ATC genotypes such as Kum Doi Saket. Overall, the loss of ATC was greater in non-glutinous than in glutinous genotypes for both WC and S-WC methods, but the reverse occurred for antioxidant capacity. WC using electric rice cooker retained higher ATC than the pressure cooking. Thus, for genotypes with high ATC and antioxidant capacity, the selection of cooking method is critical for retaining and stabilizing rice quality.展开更多
Stewing of rice grains by steam after boiling in excess water can be used for cooking rice perfectly. The effects of this procedure in cooking of three varieties of Iranian rice (Sang Tarom, Domsiyah and Fair) on te...Stewing of rice grains by steam after boiling in excess water can be used for cooking rice perfectly. The effects of this procedure in cooking of three varieties of Iranian rice (Sang Tarom, Domsiyah and Fair) on textural and morphological properties of cooked rice grains were investigated. The results showed that this step in rice cooking reduced the hardness and increased the adhesiveness of rice grains significantly. By the use of the scanning electron microscopy, it was shown that the outer surface of cooked rice stewed by steam had less porosity and closer pores due to the modification during cooking, and better gelatinization and more expansion of starch granules compared to non-stewed samples. The use of this procedure in rice cooking to provide a fully cooked and gelatinized, softer and stickier final product is recommended.展开更多
基金National Natural Science Foundation of China(52175237)。
文摘The key parameters that characterize the morphological quality of multi-layer and multi-pass metal laser deposited parts are the surface roughness and the error between the actual printing height and the theoretical model height.The Taguchi method was employed to establish the correlations between process parameter combinations and multi-objective characterization of metal deposition morphology(height error and roughness).Results show that using the signal-to-noise ratio and grey relational analysis,the optimal parameter combination for multi-layer and multi-pass deposition is determined as follows:laser power of 800 W,powder feeding rate of 0.3 r/min,step distance of 1.6 mm,and scanning speed of 20 mm/s.Subsequently,a Genetic Bayesian-back propagation(GB-BP)network is constructed to predict multi-objective responses.Compared with the traditional back propagation network,the GB-back propagation network improves the prediction accuracy of height error and surface roughness by 43.14%and 71.43%,respectively.This network can accurately predict the multi-objective characterization of morphological quality of multi-layer and multi-pass metal deposited parts.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20241931 and BK 20221371)the National Natural Science Foundation of China(32071943,32372214,and 31901444)the National Key Research and Development Program of China(2022YFD2300304)。
文摘Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.Lipid and free fatty acid contents in grains correlate positively with cooking and eating quality of rice.This study examined Yangdao 6(YD6,a conventional taste indica inbred)and Nanjing 9108(NJ9108,a superior taste japonica inbred)cultivated under conventional irrigation(CI),alternate wetting and moderate drying irrigation(AWMD),and alternate wetting and severe drying irrigation(AWSD)from 10 days after transplanting to maturity.The research investigated the relationship between lipid and free fatty acid biosynthesis in grains and the cooking and eating quality of rice.Compared to CI treatment,AWMD significantly enhanced the contents of lipid,total free fatty acids(TFFAs),free unsaturated fatty acids(FUFAs),linoleic acid,and oleic acid in milled rice by increasing activities of enzymes associated with lipid synthesis,while AWSD produced opposite effects.Correlation analysis revealed that elevated levels of lipid,TFFAs,FUFAs,linoleic acid,and oleic acid contribute to improved rice cooking and eating quality.The findings demonstrate that AWMD enhances cooking and eating quality of milled rice through optimization of lipid and fatty acid synthesis in rice grains.
基金supported by the National Key Research and Development Program of China(No.2022YFB3404700)the National Natural Science Foundation of China(Nos.52105313 and 52275299)+2 种基金the Research and Development Program of Beijing Municipal Education Commission,China(No.KM202210005036)the Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0701)the National Defense Basic Research Projects of China(No.JCKY2022405C002).
文摘At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass components.In this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool head.The material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys.The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center area.Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped zone.The tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition sample.It is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area.The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.
基金Supported by the National Natural Science Foundation of China(Grant No.52172409)Postdoctoral Innovation Talents Support Program(Grant No.BX20240298)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2682024GF023)Heilongjiang Province Postdoctoral Foundation Project(Grant No.LBH-Z23041).
文摘The huge impact kinetic energy cannot be quickly dissipated by the energy-absorbing structure and transferred to the other vehicle through the car body structure,which will cause structural damage and threaten the lives of the occupants.Therefore,it is necessary to understand the laws of energy conversion,dissipation and transfer during train collisions.This study proposes a multi-layer progressive analysis method of energy flow during train collisions,considering the characteristics of the train.In this method,the train collision system is divided into conversion,dissipation,and transfer layers from the perspective of the train,collision interface,and car body structure to analyze the energy conversion,dissipation and transfer characteristics.Taking the collision process of a rail train as an example,a train collision energy transfer path analysis model was established based on power flow theory.The results show that when the maximum mean acceleration of the vehicle meets the standard requirements,the jerk may exceed the allowable limit of the human body,and there is a risk of injury to the occupants of a secondary collision.The decay rate of the collision energy along the direction of train operation reaches 79%.As the collision progresses,the collision energy gradually converges in the structure with holes,and the structure deforms when the gathered energy is greater than the maximum energy the structure can withstand.The proposed method helps to understand the train collision energy flow law and provides theoretical support for the train crashworthiness design in the future.
基金Nourah bint Abdulrahman University for funding this project through the Researchers Supporting Project(PNURSP2025R319)Riyadh,Saudi Arabia and Prince Sultan University for covering the article processing charges(APC)associated with this publication.Special acknowledgement to Automated Systems&Soft Computing Lab(ASSCL),Prince Sultan University,Riyadh,Saudi Arabia.
文摘The growing incidence of cyberattacks necessitates a robust and effective Intrusion Detection Systems(IDS)for enhanced network security.While conventional IDSs can be unsuitable for detecting different and emerging attacks,there is a demand for better techniques to improve detection reliability.This study introduces a new method,the Deep Adaptive Multi-Layer Attention Network(DAMLAN),to boost the result of intrusion detection on network data.Due to its multi-scale attention mechanisms and graph features,DAMLAN aims to address both known and unknown intrusions.The real-world NSL-KDD dataset,a popular choice among IDS researchers,is used to assess the proposed model.There are 67,343 normal samples and 58,630 intrusion attacks in the training set,12,833 normal samples,and 9711 intrusion attacks in the test set.Thus,the proposed DAMLAN method is more effective than the standard models due to the consideration of patterns by the attention layers.The experimental performance of the proposed model demonstrates that it achieves 99.26%training accuracy and 90.68%testing accuracy,with precision reaching 98.54%on the training set and 96.64%on the testing set.The recall and F1 scores again support the model with training set values of 99.90%and 99.21%and testing set values of 86.65%and 91.37%.These results provide a strong basis for the claims made regarding the model’s potential to identify intrusion attacks and affirm its relatively strong overall performance,irrespective of type.Future work would employ more attempts to extend the scalability and applicability of DAMLAN for real-time use in intrusion detection systems.
基金Project(2023YFC3707800)supported by the National Key Research and Development Program of China。
文摘In practical engineering construction,multi-layered barriers containing geomembranes are extensively applied to retard the migration of pollutants.However,the associated analytical theory on pollutants diffusion still needs to be further improved.In this work,general analytical solutions are derived for one-dimensional diffusion of degradable organic contaminant(DOC)in the multi-layered media containing geomembranes under a time-varying concentration boundary condition,where the variable substitution and separated variable approaches are employed.These analytical solutions with clear expressions can be used not only to study the diffusion behaviors of DOC in bottom and vertical composite barrier systems,but also to verify other complex numerical models.The proposed general analytical solutions are then fully validated via three comparative analyses,including comparisons with the experimental measurements,an existing analytical solution,and a finite-difference solution.Ultimately,the influences of different factors on the composite cutoff wall’s(CCW,which consists of two soil-bentonite layers and a geomembrane)service performance are investigated through a composite vertical barrier system as the application example.The findings obtained from this investigation can provide scientific guidance for the barrier performance evaluation and the engineering design of CCWs.This application example also exhibits the necessity and effectiveness of the developed analytical solutions.
文摘"Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also the cooking techniques,ingredients selection,seasoning skills and dish innovation of Sichuan cuisine.Doing a good job in the teaching of"Sichuan Cuisine Cooking Skills"is of great significance to the cultivation and reserve of culinary professionals in China,and also has an important impact on students'employment competitiveness.Under the background of"new engineering education",the course reform of"Sichuan Cuisine Cooking Skills"was carried out in terms of the construction of teaching staff,teaching methods,students'participation degree and the innovation of course content,and specific reform suggestions were put forward,hoping to effectively promote the sustainable development of"Sichuan Cuisine Cooking Skills"and effectively improve the teaching quality.
基金supported by the National Natural Science Foundation of China(U20A2022 and 32372217)the National Key Research and Development Program of China(2022YFD2300700)the Free Exploration Program of State Key Laboratory of Crop Gene Exploration and Utilization in Sichuan Basin,China(SKL-ZY202216)。
文摘Adjustment of the sowing date is a widely used measure in rice production for adapting to high-temperature conditions.However,the impact of a delayed sowing date(DS)on rice quality may vary by variety and ecological conditions.In this study,we conducted experiments using four different sowing dates,the conventional sowing date 1(CS1),CS2(10 d later than CS1),DS1(30 d later than CS1),and DS2(30 d later than CS2),and three rice varieties,i.e.,Yixiangyou 2115,Fyou 498,and Chuanyou 6203.This experiment was conducted at four sites in the Sichuan Basin in 2018 and 2019 to evaluate the infuence of DS on the pasting properties of rice,which are a proxy for the eating and cooking quality(ECQ).In DS1 and DS2,the rice had a signifcantly greater amylose content(AC)but a lower protein content(PC),peak viscosity(PKV),cool paste viscosity(CPV),and hot paste viscosity(HPV)than in CS1 and CS2.Moreover,except for CS2 and DS1 in 2018,DS1 and DS2 led to 2.15-11.19%reductions in breakdown viscosity(BDV)and 23.46-108.47%increases in setback viscosity(SBV).However,the infuence of DS on rice pasting properties varied by study site and rice variety.In 2019,DS1 and DS2 led to BDV reductions of 2.35-9.33,2.61-8.61,10.03-17.78,and 2.06-8.93%,and SBV increases of 2.32-60.93,63.74-144.24,55.46-91.63,and-8.28-65.37%at the Dayi,Anzhou,Nanbu,and Shehong(except for SBV in CS2 and DS1)sites,respectively.DS resulted in greater reductions in PKV,HPV,CPV,and BDV and greater increases in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.The correlation analysis indicated that PKV and HPV were signifcantly and positively related to the mean,maximum,and minimum temperatures after heading.These temperatures must be greater than 25.9,31.2,and 22.3℃,respectively,to increase the relative BDV and reduce the relative SBV of rice,thereby enhancing ECQ.In conclusion,DS might contribute to a signifcant deterioration in ECQ in machine-transplanted rice in the Sichuan Basin.A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice.
基金supported by Fundamental Research Funds for the Central Universities(No.lzujbky-2024-05)Innovation Foundation of Provincial Education Department of Gansu(2024B-005)+2 种基金Scientific Department of Gansu(24CXGA083,24CXGA024,JK2024-28,JK2024-32 and 23CXJA0007)Industrial Support Plan Project of Provincial Education Department of Gansu(2025CYZC-003 and CYZC-2024-10)the Hunan Natural Science Foundation Science and Education Joint Fund Project(2022JJ60109).
文摘Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanisms in these multi-layer composites is essential,as it offers intuitive insights into parametric influences and facilitates enhanced structural performance.This paper employs an improved transfer matrix method to address the limitations of existing theoretical approaches for analyzing multi-layer composite structures.By establishing a twodimensional composite pavement model,it investigates load transfer characteristics and validates the accuracy through finite element simulation.The proposed method offers a straightforward analytical approach for examining internal interactions between structural layers.Case studies indicate that the concrete surface layer is the main load-bearing layer for most vertical normal and shear stresses.The soil base layer reduces the overall mechanical response of the substructure,while horizontal actions increase the risk of interfacial slip and cracking.Structural optimization analysis demonstrates that increasing the thickness of the concrete surface layer,enhancing the thickness and stiffness of the soil base layer,or incorporating gradient layers can significantly mitigate these risks of interfacial slip and cracking.The findings of this study can guide the optimization design,parameter analysis,and damage prevention of multi-layer composite structures.
基金Projects(42477162,52108347,52178371,52168046,52178321,52308383)supported by the National Natural Science Foundation of ChinaProjects(2023C03143,2022C01099,2024C01219,2022C03151)supported by the Zhejiang Key Research and Development Plan,China+6 种基金Project(LQ22E080010)supported by the Exploring Youth Project of Zhejiang Natural Science Foundation,ChinaProject(LR21E080005)supported by the Outstanding Youth Project of Natural Science Foundation of Zhejiang Province,ChinaProject(2022M712964)supported by the Postdoctoral Science Foundation of ChinaProject(2023AFB008)supported by the Natural Science Foundation of Hubei Province for Youth,ChinaProject(202203)supported by Engineering Research Centre of Rock-Soil Drilling&Excavation and Protection,Ministry of Education,ChinaProject(202305-2)supported by the Science and Technology Project of Zhejiang Provincial Communication Department,ChinaProject(2021K256)supported by the Construction Research Founds of Department of Housing and Urban-Rural Development of Zhejiang Province,China。
文摘This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.
基金supported by the National Natural Science Foundation of China(No.62401597)Natural Science Foundation of Hunan Province,China(No.2024JJ6469)the Research Project of National University of Defense Technology,China(No.ZK22-02).
文摘Low Earth Orbit(LEO)mega-constellation networks,exemplified by Starlink,are poised to play a pivotal role in future mobile communication networks,due to their low latency and high capacity.With the massively deployed satellites,ground users now can be covered by multiple visible satellites,but also face complex handover issues with such massive high-mobility satellites in multi-layer.The end-to-end routing is also affected by the handover behavior.In this paper,we propose an intelligent handover strategy dedicated to multi-layer LEO mega-constellation networks.Firstly,an analytic model is utilized to rapidly estimate the end-to-end propagation latency as a key handover factor to construct a multi-objective optimization model.Subsequently,an intelligent handover strategy is proposed by employing the Dueling Double Deep Q Network(D3QN)-based deep reinforcement learning algorithm for single-layer constellations.Moreover,an optimal crosslayer handover scheme is proposed by predicting the latency-jitter and minimizing the cross-layer overhead.Simulation results demonstrate the superior performance of the proposed method in the multi-layer LEO mega-constellation,showcasing reductions of up to 8.2%and 59.5%in end-to-end latency and jitter respectively,when compared to the existing handover strategies.
基金supported by the National Key R&D Program of China(Nos.2022YFC3701000 and 2021YFA1601800)the National Natural Science Foundation of China(Nos.42230701 and 42375105)+1 种基金the Foundation for Program of Science and Technology Research(No.2024A1515011937)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049).
文摘Particulate levoglucosan is an important tracer for biomass burning emission in ambient air.However,recent studies question its reliability as a biomass burning tracer in Chinesemega cities due to important contribution from potential non-biomass burning sources,such as cooking.To address this,we examined the dynamic variation and sources of levoglucosan using a chemical ionization mass spectrometer and other advanced instruments during Beijing’s summer of 2021.The average mass concentration of levoglucosan and its isomer(C_(6)H_(10)O_(5))was 0.025±0.014μg/m^(3),constituting 0.55%±0.32%of total organic carbon(OC)in this campaign.Despite cooking emissions contributing significantly to the organic aerosol(OA,20%),levoglucosan and its isomers correlated more strongly with biomass-burning related tracers(R>0.6),black carbon(R=0.72)and less so with cooking-related sources(R=0.3).This indicates that levoglucosan is primarily dominated by biomass-burning emissions rather than cooking in Beijing’s urban areas during summertime.The diurnal variation of levoglucosan concentrations highlighted the importance of daytime and nocturnal biomass burning emissions during polluted periods in Beijing.Using levoglucosan as a tracer to quantify the biomass burning OC(BBOC),we found good agreement on the time series of BBOC between the tracermethod and other independent source apportionmentmethod.This reaffirms the reliability of levoglucosan as a biomass burning tracer.Biomass burning contributed an average of 7%-8%to OC,highlighting its significant impact on Beijing’s summer air quality.Our study enhances understanding of biomass burning influences on ambient aerosol in typical urban areas.
文摘Stab-resistant textiles play a critical role in personal protection,necessitating a deeper understanding of how structural and layering factors influence their performance.The current study experimentally examines the effects of textile structure,layering,and ply orientation on the stab resistance of multi-layer textiles.Three 3D warp interlock(3DWI)structures({f1},{f2},{f3})and a 2D woven fabric({f4}),all made of high-performance p-aramid yarns,were engineered and manufactured.Multi-layer specimens were prepared and subjected to drop-weight stabbing tests following HOSBD standards.Stabbing performance metrics,including Depth of Trauma(DoT),Depth of Penetration(DoP),and trauma deformation(Ymax,Xmax),were investigated and analyzed.Statistical analyses(Two-and One-Way ANOVA)indicated that fabric type and layer number significantly impacted DoP(P<0.05),while ply orientation significantly affected DoP(P<0.05)but not DoT(P>0.05).Further detailed analysis revealed that 2D woven fabrics exhibited greater trauma deformation than 3D WIF structures.Increasing the number of layers reduced both DoP and DoT across all fabric structures,with f3 demonstrating the best performance in multi-layer configurations.Aligned ply orientations also enhanced stab resistance,underscoring the importance of alignment in dissipating impact energy.
基金supported by the National Natural Science Foundation of China(No.52330002)the Natural Science Foundation of Beijing Municipality(No.8232020)the First Batch of Key Disciplines on Public Health in Chongqing(YWBF2022072).
文摘Objectives To characterize fine particulate matter(PM_(2.5))-bound polycyclic aromatic hydrocarbons(PAHs)emitted from different cooking fumes and their exposure routes and assess their health-associated impact to provide a reference for health risk prevention from PAH exposure across different age and sex groups.Methods Sixteen PM_(2.5)-bound PAHs emitted from 11 cooking styles were analyzed using GC-MS/MS.The health hazards of these PAHs in the Handan City population(stratified by age and sex)were predicted using the incremental lifetime cancer risk(ILCR)model.The respiratory deposition doses(RDDs)of the PAHs in children and adults were calculated using the PM_(2.5)deposition rates in the upper airway,tracheobronchial,and alveolar regions.Results The total concentrations of PM_(2.5)-bound PAHs ranged from 61.10 to 403.80 ng/m3.Regardless of cooking styles,the ILCRtotal values for adults(1.23×10^(-6)to 3.70×10^(-6))and older adults(1.28×10^(-6)to 3.88×10^(-6))exceeded the acceptable limit of 1.00×10^(-6).With increasing age,the ILCRtotal value first declined and then increased,varying substantially among the population groups.Cancer risk exhibited particularly high sensitivity to short exposure to barbecue-derived PAHs under equivalent body weights.Furthermore,barbecue,Sichuan and Hunan cuisine,Chinese cuisine,and Chinese fast food were associated with higher RDDs for both adults and children.Conclusion ILCRtotal values exceeded the acceptable limit for both females and males of adults,with all cooking styles showing a potentially high cancer risk.Our findings serve as an important reference for refining regulatory strategies related to catering emissions and mitigating health risks associated with cooking styles.
基金Supported by the Development Project of Community Health Nursing Innovative Practice Model of China(CMB08883)
文摘Cooking fumes (CFs) are mixtures of many toxic components, such as aldehydes, heterocyclic amines, polycyclic aromatic hydrocarbons, fat aerosols and particulate matters. CFs exposure has been proven to be associated with many diseases. Lung cancer takes the leading place among the diseases being reported caused by CFs exposure. Molecular and biochemical studies have found that CFs exposure may lead to lung cancer by gene damage, formation of reactive oxygen species, blockage of related proteins’ function, and even cell death. However, reviews about the mechanisms of how CFs exposure leads to lung cancer are still lacking. Elucidation of the mechanisms of lung cancer caused by CFs exposure may provide a new insight into the prevention of lung cancer caused by CFs exposure, as well as laying the foundation for the toxicity study of CFs. In this minor review, the mechanisms of how CFs exposure leads to lung cancer were summarized and discussed.
文摘PM 2.5 samples were collected by a three-stage cascade impactor at two kinds of Chinese restaurants to characterize fine organic particulate matter from Chinese cooking sources. Major individual organic compounds have been quantified by GC/MS, including series of alkanes, n-alkanoic acids, n-alkanals, alkan-2-ones and PAHs. Alkanes and ketones make up a significant fraction of particle-phase organic compounds, ranging from C 11 to C 26, and C 9 to C 19, respectively. In addition, other organic compound classes have been identified, such as alkanols, esters, furans, lactones, amides, and nitriles. The mass concentrations of fine particles, alkanes, n-alkanoic acids and PAHs in air emitted from the Uigur style cooking are hundreds times higher than ambient PM 2.5in Beijing.
文摘Cooking and nutrition qualities of grain are two of the most important aspects of rice quality. To understand the difference in cooking and nutrition qualities among the grains at different positions within a rice panicle, the distributions of gel consistency (GC), amylose content (AC) and crude protein content (CPC) of grains in a panicle in association with different nitrogen levels (0, 120 and 240 k c/ha) were investigated by using two rice varieties, Yangdao 6 (indica) and Wuyujing 3 (japonica). In general, the grains at the basal part of a panicle had lower GC and higher AC than those at the upper or middle part of a panicle. The 1^st grain on the secondary branch with earlier flowering exhibited the highest GC, whereas the 2nd grain on the primary branch with later flowering showed the highest AC. For Yangdao 6, CPC in the grains on the primary branches was lower at the middle part of a panicle than at the upper or basal part of a panicle. For Wuyujing 3, there were no significant differences in CPCs in the grains among the upper, middle and basal parts of a panicle. GC in the grains was increased, whereas AC was reduced from zero nitrogen application (ON) to low amount of nitrogen application (LN), and the result was reversed from LN to medium amount of nitrogen application (MN). CPC was increased with the increase in the amount of nitrogen application.
基金the Royal Golden Jubilee Ph.D.Program(Grant No.PHD/0098/2556)the Functional Food Research Centre for Well-Being,Chiang Mai University,Thailand for financial supported
文摘Purple rice is a source of bioactive antioxidants for rice consumers. Loss of the major antioxidant compounds after a range of cooking processes was evaluated by measuring the changes in anthocyanin concentration (ATC) and antioxidant capacity (DPPH activity) of four non-glutinous and four glutinous genotypes. However, soaking in water prior to cooking generally decreased more ATC and antioxidant capacity in non-glutinous than in glutinous genotypes. Wet cooking (WC) and soaking before wet cooking (S-WC) led to lose almost all the ATC and antioxidant capacity with only slight variation between genotypes. In the glutinous genotype Pieisu, which had the highest raw rice ATC, ATC remained the highest when cooked by the WC method. By contrast, almost no ATC remained after WC and S-WC in the low ATC genotypes such as Kum Doi Saket. Overall, the loss of ATC was greater in non-glutinous than in glutinous genotypes for both WC and S-WC methods, but the reverse occurred for antioxidant capacity. WC using electric rice cooker retained higher ATC than the pressure cooking. Thus, for genotypes with high ATC and antioxidant capacity, the selection of cooking method is critical for retaining and stabilizing rice quality.
文摘Stewing of rice grains by steam after boiling in excess water can be used for cooking rice perfectly. The effects of this procedure in cooking of three varieties of Iranian rice (Sang Tarom, Domsiyah and Fair) on textural and morphological properties of cooked rice grains were investigated. The results showed that this step in rice cooking reduced the hardness and increased the adhesiveness of rice grains significantly. By the use of the scanning electron microscopy, it was shown that the outer surface of cooked rice stewed by steam had less porosity and closer pores due to the modification during cooking, and better gelatinization and more expansion of starch granules compared to non-stewed samples. The use of this procedure in rice cooking to provide a fully cooked and gelatinized, softer and stickier final product is recommended.