期刊文献+
共找到3,376篇文章
< 1 2 169 >
每页显示 20 50 100
Effect of thermal processing and fermentation with Chinese traditional starters on characteristics and allergenicity of wheat matrix 被引量:1
1
作者 Huan Rao Xi Li Wentong Xue 《Food Science and Human Wellness》 SCIE CSCD 2023年第3期789-794,共6页
Wheat allergy has become a serious health threat worldwide and its prevalence has increased alarmingly in the past few years.Factors such as food matrix and food processing may alter the structure of wheat proteins,an... Wheat allergy has become a serious health threat worldwide and its prevalence has increased alarmingly in the past few years.Factors such as food matrix and food processing may alter the structure of wheat proteins,and hence affect its allergenic properties.However,few reports have focused on the influence of Chinese traditional starter fermentation on wheat allergy.In this study,5 starters from different regions of China were used for fermentation,and protein characteristics were monitored by sodium dodecyl sulfate polyacrylamide gel electropheresis,and immunoreactivity analyzed by immunoassay with allergenic serum was obtained from New Zealand white rabbits.The allergenicity of steamed and baked matrices was also evaluated.The results showed that the allergenicity of wheat dough was basically increased at the beginning and then decreased during fermentation,but specific trends depend on different starters.With the progress of fermentation,especially as pH value decreased to 3.0-4.0,the allergenicity decreased significantly.Baking and steaming can reduce the allergenicity of wheat matrix,but fermentation is not a key factor affecting the allergenic activity of proteins.Our results can provide a theoretical basis for controlling wheat allergenicity in food proces sing or producing hypoallergenic food. 展开更多
关键词 Chinese traditional starter ermentation characteristics thermal processing ALLERGENICITY Wheat matrix
下载PDF
A systematic printability study of direct ink writing towards high-resolution rapid manufacturing
2
作者 Qingyang Zheng Bin Xie +1 位作者 Zhoulong Xu Hao Wu 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2023年第3期500-517,共18页
Direct ink writing(DIW)holds enormous potential in fabricating multiscale and multi-functional architectures by virtue of its wide range of printable materials,simple operation,and ease of rapid prototyping.Although i... Direct ink writing(DIW)holds enormous potential in fabricating multiscale and multi-functional architectures by virtue of its wide range of printable materials,simple operation,and ease of rapid prototyping.Although it is well known that ink rheology and processing parameters have a direct impact on the resolution and shape of the printed objects,the underlying mechanisms of these key factors on the printability and quality of DIW technique remain poorly understood.To tackle this issue,we systematically analyzed the printability and quality through extrusion mechanism modeling and experimental validating.Hybrid non-Newtonian fluid inks were first prepared,and their rheological properties were measured.Then,finite element analysis of the whole DIW process was conducted to reveal the flow dynamics of these inks.The obtained optimal process parameters(ink rheology,applied pressure,printing speed,etc)were also validated by experiments where high-resolution(<100μm)patterns were fabricated rapidly(>70 mm s^(-1)).Finally,as a process research demonstration,we printed a series of microstructures and circuit systems with hybrid inks and silver inks,showing the suitability of the printable process parameters.This study provides a strong quantitative illustration of the use of DIW for the high-speed preparation of high-resolution,high-precision samples. 展开更多
关键词 direct ink writing extrusion mechanism modelling computational fluid dynamic(CFD) printability process parameters high-resolution printing
下载PDF
Field observation of the thermal disturbance and freezeback processes of cast-in-place pile foundations in warm permafrost regions
3
作者 Xin Hou Ji Chen +4 位作者 YouQian Liu PengFei Rui JingYi Zhao ShouHong Zhang HaiMing Dang 《Research in Cold and Arid Regions》 CSCD 2023年第1期18-26,共9页
The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the therm... The bearing capacity of pile foundations is affected by the temperature of the frozen soil around pile foundations.The construction process and the hydration heat of cast-in-place(CIP)pile foundations affect the thermal stability of permafrost.In this paper,temperature data from inside multiple CIP piles,borehole observations of ground thermal status adjacent to the foundations and local weather stations were monitored in warm permafrost regions to study the thermal influence process of CIP pile foundations.The following conclusions are drawn from the field observation data.(1)The early temperature change process of different CIP piles is different,and the differences gradually diminish over time.(2)The initial concrete temperature is linearly related with the air temperature,net radiation and wind speed within 1 h before the completion of concrete pouring;the contributions of the air temperature,net radiation,and wind speed to the initial concrete temperature are 51.9%,20.3%and 27.9%,respectively.(3)The outer boundary of the thermal disturbance annulus is approximately 2 m away from the pile center.It took more than 224 days for the soil around the CIP piles to return to the natural permafrost temperature at the study site. 展开更多
关键词 PERMAFROST Cast-in-place pile foundations thermal disturbance Freezeback process Initial concrete temperature
下载PDF
High-resolution Transmission Electron Microscopy Characterization of the Structure of Cu Precipitate in a Thermal-aged Multicomponent Steel 被引量:1
4
作者 Lizhan Han Qingdong Liu Jianfeng Gu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第5期117-124,共8页
High-dispersed nanoscale Cu precipitates often contribute to extremely high strength due to precipitation hardening,and whereas usually lead to degraded toughness for especially ferritic steels.Hence,it is important t... High-dispersed nanoscale Cu precipitates often contribute to extremely high strength due to precipitation hardening,and whereas usually lead to degraded toughness for especially ferritic steels.Hence,it is important to understand the formation behaviors of the Cu precipitates.High-resolution transmission electron microscopy(TEM)is utilized to investigate the structure of Cu precipitates thermally formed in a high-strength low-alloy(HSLA)steel.The Cu precipitates were generally formed from solid solution and at the crystallographic defects such as martensite lath boundaries and dislocations.The Cu precipitates in the same aging condition have various structure of BCC,9 R and FCC,and the structural evolution does not greatly correlate with the actual sizes.The presence of different structures in an individual Cu precipitate is observed,which reflects the structural transformation occurring locally to relax the strain energy.The multiply additions in the steel possibly make the Cu precipitation more complex compared to the binary or the ternary Fe-Cu alloys with Ni or Mn additions.This research gives constructive suggestions on alloying design of Cu-bearing alloy steels. 展开更多
关键词 CU PRECIPITATE high-resolution transmission electron microscopy thermal aging HIGH-STRENGTH low-alloy STEEL
下载PDF
Effects of different thermal processing methods on bioactive components,phenolic compounds,and antioxidant activities of Qingke(highland hull-less barley)
5
作者 Qingyue Hong Guangjing Chen +2 位作者 Zhirong Wang Xuhui Chen Jianquan Kan 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期119-129,共11页
Qingke(highland hull-less barley)is a grain replete with substantial nutrients and bioactive ingredients.In this study,we evaluated the effects of boiling(BO),steaming(ST),microwave baking(MB),far-infrared baking(FB),... Qingke(highland hull-less barley)is a grain replete with substantial nutrients and bioactive ingredients.In this study,we evaluated the effects of boiling(BO),steaming(ST),microwave baking(MB),far-infrared baking(FB),steam explosion(SE),and deep frying(DF)on bioactive components,phenolic compounds,and antioxidant activities of Qingke compared with the effects of traditional roast(TR).Results showed that the soluble dietary fiber,beta-glucan and water-extractable pentosans of Qingke in dry heat processes of TR,SE,MB and FB had a higher content compared with other thermal methods and had a better antioxidant activity of hydroxyl radical scavenging and a better reduction capacity,while those in wet heat processes of BO and ST had a better antioxidant activity of ABTS radical scavenging and a better Fe^(2+) chelating ability.DF-and SE-Qingke had a higher content of tocopherol,phenolic,and flavonoid.Overall,6 free phenolic compounds and 12 bound phenolic compounds of Qingke were identified,and free phenolic compounds suffered more damage during thermal processing.Principal component analysis showed that SE had more advantages in retaining and improving the main biological active ingredients of Qingke,and it may be the best method for treating Qingke. 展开更多
关键词 Qingke(highland hull-less barley) thermal processing Antioxidant activity Phenolic compounds Bioactive components
下载PDF
Effect of safety valve types on the gas venting behavior and thermal runaway hazard severity of large-format prismatic lithium iron phosphate batteries
6
作者 Zhuangzhuang Jia Yuanyuan Min +5 位作者 Peng Qin Wenxin Mei Xiangdong Meng Kaiqiang Jin Jinhua Sun Qingsong Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期195-207,I0006,共14页
The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the ... The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design. 展开更多
关键词 Lithium iron phosphate battery Safety valve thermal runaway Gas venting behavior thermal runaway hazard severity Gray-fuzzy analytic hierarchy process
下载PDF
Fabrication and Characterization of Bamboo—Epoxy Reinforced Composite for Thermal Insulation
7
作者 Nandavardhan Reddy Kopparthi Jens Schuster Yousuf Pasha Shaik 《Open Journal of Composite Materials》 2024年第1期15-32,共18页
As global warming intensifies, researchers worldwide strive to develop effective ways to reduce heat transfer. Among the natural fiber composites studied extensively in recent decades, bamboo has emerged as a prime ca... As global warming intensifies, researchers worldwide strive to develop effective ways to reduce heat transfer. Among the natural fiber composites studied extensively in recent decades, bamboo has emerged as a prime candidate for reinforcement. This woody plant offers inherent strengths, biodegradability, and abundant availability. Due to its high cellulose content, its low thermal conductivity establishes bamboo as a thermally resistant material. Its low thermal conductivity, enhanced by a NaOH solution treatment, makes it an excellent thermally resistant material. Researchers incorporated Hollow Glass Microspheres (HGM) and Kaolin fillers into the epoxy matrix to improve the insulating properties of bamboo composites. These fillers substantially enhance thermal resistance, limiting heat transfer. Various compositions, like (30% HGM + 25% Bamboo + 65% Epoxy) and (30% Kaolin + 25% Bamboo + 45% Epoxy), were compared to identify the most efficient thermal insulator. Using Vacuum Assisted Resin Transfer Molding (VARTM) ensures uniform distribution of fillers and resin, creating a structurally sound thermal barrier. These reinforced composites, evaluated using the TOPSIS method, demonstrated their potential as high-performance materials combating heat transfer, offering a promising solution in the battle against climate change. 展开更多
关键词 thermal Insulator Rooftiles Hollow Glass Microspheres BAMBOO KAOLIN EPOXY VARTM process thermal Conductivity Mechanical Properties
下载PDF
Real Time Thermal Image Based Machine Learning Approach for Early Collision Avoidance System of Snowplows
8
作者 Fletcher Wadsworth Suresh S. Muknahallipatna Khaled Ksaibati 《Journal of Intelligent Learning Systems and Applications》 2024年第2期107-142,共36页
In an effort to reduce vehicle collisions with snowplows in poor weather conditions, this paper details the development of a real time thermal image based machine learning approach to an early collision avoidance syst... In an effort to reduce vehicle collisions with snowplows in poor weather conditions, this paper details the development of a real time thermal image based machine learning approach to an early collision avoidance system for snowplows, which intends to detect and estimate the distance of trailing vehicles. Due to the operational conditions of snowplows, which include heavy-blowing snow, traditional optical sensors like LiDAR and visible spectrum cameras have reduced effectiveness in detecting objects in such environments. Thus, we propose using a thermal infrared camera as the primary sensor along with machine learning algorithms. First, we curate a large dataset of thermal images of vehicles in heavy snow conditions. Using the curated dataset, two machine-learning models based on the modified ResNet architectures were trained to detect and estimate the trailing vehicle distance using real-time thermal images. The trained detection network was capable of detecting trailing vehicles 99.0% of the time at 1500.0 ft distance from the snowplow. The trained trailing distance network was capable of estimating distance with an average estimation error of 10.70 ft. The inference performance of the trained models is discussed, along with the interpretation of the performance. 展开更多
关键词 Convolutional Neural Networks Residual Networks Object Detection Image processing thermal Imaging
下载PDF
Methane Conversion Using Dielectric Barrier Discharge: Comparison with Thermal Process and Catalyst Effects 被引量:4
9
作者 Antonius Indarto Jae-Wook Choi +1 位作者 Hwaung Lee Hyung Keun Song 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第2期87-92,共6页
The direct conversion of methane using a dielectric barrier discharge has been experimentally studied. Experiments with different values of flow rates and discharge voltages have been performed to investigate the effe... The direct conversion of methane using a dielectric barrier discharge has been experimentally studied. Experiments with different values of flow rates and discharge voltages have been performed to investigate the effects on the conversion and reaction products both qualitatively and quantitatively. Experimental results indicate that the maximum conversion of methane has been 80% at an input flow rate of 5 ml/min and a discharge voltage of 4 kV. Experimental results also show that the optimum condition has occurred at a high discharge voltage and higher input flow rate. In terms of product distribution, a higher flow rate or shorter residence time can increase the selectivity for higher hydrocarbons. No hydrocarbon product was detected using the thermal method, except hydrogen and carbon. Increasing selectivity for ethane was found when Pt and Ru catalysts presented in the plasma reaction. Hydrogenation of acetylene in the catalyst surface could have been the reason for this phenomenon as the selectivity for acetylene in the products was decreasing. 展开更多
关键词 PLASMA dielectric barrier discharge thermal process methane conversion CATALYST
下载PDF
Application of Spectral Angle Mapper Classification to Discriminate Hydrothermal Alteration in Southwest Birjand, Iran, Using Advanced Spaceborne Thermal Emission and Reflection Radiometer Image Processing 被引量:5
10
作者 Maryam ABDI Mohammd H. KARIMPOUR 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第5期1289-1296,共8页
The purpose of this study is to evaluate the Spectral Angle Mapper (SAM) classification method for determining the optimum threshold (maximum spectral angle) to unveil the hydrothermal mineral assemblages related ... The purpose of this study is to evaluate the Spectral Angle Mapper (SAM) classification method for determining the optimum threshold (maximum spectral angle) to unveil the hydrothermal mineral assemblages related to mineral deposits. The study area indicates good potential for Cu-Au porphyry, epithermal gold deposits and hydrothermal alteration well developed in arid and semiarid climates, which makes this region significant for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image processing analysis. Given that achieving an acceptable mineral mapping requires knowing the alteration patterns, petrochemistry and petrogenesis of the igneous rocks while considering the effect of weathering, overprinting of supergene alteration, overprinting of hypogene alteration and host rock spectral mixing, SAM classification was implemented for argillic, sericitic, propylitic, alunitization, silicification and iron oxide zones of six previously known mineral deposits: Maherabad, a Cu-Au porphyry system; Sheikhabad, an upper part of Cu-Au porphyry system; Khoonik, an Intrusion related Au system; Barmazid, a low sulfidation epithermal system; Khopik, a Cu-Au porphyry system; and Hanish, an epithermal Au system. Thus, the investigation showed that although the whole alteration zones are affected by mixing, it is also possible to produce a favorable hydrothermal mineral map by such complementary data as petrology, petrochemistry and alteration patterns. 展开更多
关键词 hydrothermal alteration Spectral Angle Mapper Advanced Spaceborne thermal Emission and Reflection Radiometer image process Iran
下载PDF
Research on Development of Dolomite-Ferrosilicon Thermal Reduction Process of Magnesium Production 被引量:3
11
作者 李华清 谢水生 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第S1期606-610,共5页
Up to now, the Pedgion magnesium reduction process is the dominating magnesium production process. In 2004, about 98% of raw magnesium is produced by Pedgion magnesium reduction process in China which equals to 60% of... Up to now, the Pedgion magnesium reduction process is the dominating magnesium production process. In 2004, about 98% of raw magnesium is produced by Pedgion magnesium reduction process in China which equals to 60% of the global output. It shows that the dolomite-ferrosilicon thermal reduction process is the most important method to produce magnesium in the world. Limited by the disadvantage of dolomite-ferrosilicon thermal reduction process, the magnesium producing process always followed by relatively severe pollution, while the resource utilizing efficiency keeps very low. With the rapid development of dolomite-ferrosilicon thermal reduction process in China, many research works have been done aiming at the process technology and the reduction theory, and the magnesium producing process has got great evolution. The history of dolomite-ferrosilicon thermal reduction process was introduced; the process character, the merits and which defects were also discussed. Defects in dolomite-ferrosilicon thermal reduction process were expatiated, and feasible method and idea to upgrade the process was put forward. The main problems and the potential troubles hindering the development of magnesium industry were analyzed. Finally, the probability to further improve the thermal reduction process and the effective approaches to develop Chinese magnesium industry were discussed. 展开更多
关键词 Pedgion process dolomite-ferrosilicon thermal reduction process
下载PDF
Thermal Evolution of Plutons and Uplift Process of the Yanshan Orogenic Belt 被引量:2
12
作者 WU Zhenhan CUI Shengqin +2 位作者 ZHU Dagang FENG Xiangyang MA Yinsheng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第1期7-13,共7页
Abstract: Thermochronological dating was used to study the thermal evolution of the Mesozoic plutons and uplift history of the Yanshan orogenic belt. The results show that the cooling history of the plutons is complic... Abstract: Thermochronological dating was used to study the thermal evolution of the Mesozoic plutons and uplift history of the Yanshan orogenic belt. The results show that the cooling history of the plutons is complicated, corresponding to the inhomogeneous uplift process of the Yanshan orogenic belt. The Panshan granite cooled fast during 226.48–204.95 Ma at a rate of 10.22°C/Ma after its emplacement at a depth of about 10 km, and its fast uplift occurred in about 96–35 Ma at an average rate of 0.115 mm/a. The Wulingshan pluton cooled fast during 132–127.23 Ma at a rate of 94.34°C/Ma, and its rapid uplift occurred in 86–45 Ma at an average rate of 0.186 mm/a. The Yunmengshan granite cooled fast during 143–120.99 Ma at a rate of 19.51°C/Ma, and its rapid uplift occurred in 106–103.95 Ma and 20–0.0 Ma at a rate of 1.06 mm/a and 0.15 mm/a respectively. The Sihetang granite-gneiss uplifted rapidly since 13 Ma at an average rate of 0.256 mm/a. The Badaling granite uplifted rapidly since 6 Ma at an average rate of 0.556 mm/a. The Cenozoic uplift of the Yanshan Mountains can be well correlated to the rifting process of the surrounding basins. 展开更多
关键词 thermal evolution uplift process thermochronological dating Yanshan orogenic belt
下载PDF
Analytical and numerical investigations of displaced thermal state evolutions in a laser process 被引量:2
13
作者 杜传勋 孟祥国 +1 位作者 张冉 王继锁 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期102-108,共7页
We investigate how displaced thermal states (DTSs) evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly ... We investigate how displaced thermal states (DTSs) evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions. 展开更多
关键词 displaced thermal state laser process infinitive operator-sum representation photon number Wigner function von Neumann entropy
下载PDF
Surface modification of magnesium alloys using thermal and solid-state cold spray processes:Challenges and latest progresses 被引量:4
14
作者 Mohammadreza Daroonparvar Hamid Reza Bakhsheshi-Rad +8 位作者 Abbas Saberi Mahmood Razzaghi Ashish K Kasar Seeram Ramakrishna Pradeep L.Menezes Manoranjan Misra Ahmad Fauzi Ismail Safian Sharif Filippo Berto 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第8期2025-2061,共37页
Potential engineering applications of magnesium(Mg)and Mg-based alloys,as the lightest structural metal,have made them a popular subject of study.However,the inferior corrosion and wear characteristics significantly l... Potential engineering applications of magnesium(Mg)and Mg-based alloys,as the lightest structural metal,have made them a popular subject of study.However,the inferior corrosion and wear characteristics significantly limit their application range.It is widely recognized that surface treatment is the most commonly utilized technique for remarkably improving a substrate’s surface characteristics.Numerous methods have been introduced for the surface treatment of Mg and Mg-based alloys to improve their corrosion behavior and tribological performance.Among these,thermal spray(TS)technology provides several methods for deposition of various functional metallic,ceramic,cermet,or other coatings tailored to particular conditions.Recent researches have shown the tremendous potential for thermal spray coated Mg alloys for biomedical and industrial applications.In this context,the cold spray(CS)method,as a comparatively new TS coating technique,can generate the coating layer using kinetic energy rather than combined thermal and kinetic energies,like the high-velocity oxy-fuel(HVOF)spray method.Moreover,the CS process,as a revolutionary method,is able to repair and refurbish with a faster turnaround time;it also provides solutions that do not require dealing with the thermal stresses that are part of the other repair processes,such as welding or other TS processes using a high-temperature flame.In this review paper,the recently designed coatings that are specifically applied to Mg alloys(primarily for industrial applications)employing various coating processes are reviewed.Because of the increased utilization of CS technology for both 3D printed(additively manufactured)coatings and repair of structurally critical components,the most recent CS methods for the surface treatment,repair,and refurbishment of Mg alloys as well as their benefits and restrictions are then discussed and reviewed in detail.Lastly,the prospects of this field of study are briefly discussed,along with a summary of the presented work. 展开更多
关键词 Mg-based alloys Surface modification thermal and cold spray processes Corrosion behavior Wear resistance
下载PDF
Numerical simulation of dynamic thermal process during doublesided asymmetrical TIG backing welding of large thick plates 被引量:2
15
作者 刘殿宝 赵慧慧 +2 位作者 李福泉 张广军 吴林 《China Welding》 EI CAS 2011年第1期44-48,共5页
The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates ( 1 000 mm×700 mm×50 mm) is numerically simulated using MSC. MARC. The effect of arc distance on the t... The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates ( 1 000 mm×700 mm×50 mm) is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance. 展开更多
关键词 numerical simulation double-sided asymmetrical TIG backing welding thermal process double heat sources on double sides
下载PDF
Modeling and simulation of 3D thermal stresses of large-sized castings in solidification processes 被引量:2
16
作者 J.Q.Wang D.W.Yu +2 位作者 X.Sun S.F.Su B.Z.Li 《China Foundry》 SCIE CAS 2004年第S1期20-24,共5页
When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large-sized steel castings, aluminum castings and etc. Some defects of hot cracking by therm... When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large-sized steel castings, aluminum castings and etc. Some defects of hot cracking by thermal stress often appear during solidification process as these castings are produced, which results in failure of castings. Therefore predicting the effects of technological parameters for production of castings on the thermal stress during solidification process becomes an important means. In this paper, the mathematical models have been established and numerical calculation of temperature fields by using finite difference method (FDM) and then thermal stress fields by using finite element method (FEM) during solidification process of castings have been carried out. The technological parameters of production have been optimized by the results of calculation and the defects of hot cracking have been eliminated. Modeling and simulation of 3D thermal stress during solidification processes of large-sized castings provided a scientific basis, which promoted further development of advanced manufacturing technique. 展开更多
关键词 Large-sized castings simulation of 3D temperature fields simulation of 3D thermal stress fields defect of hot cracking solidification process
下载PDF
Perturbation Solutions for Thermal Process of Honeycomb Regenerator 被引量:1
17
作者 AI Yuan-fang MEI Chi HUANG Guo-dong JIANG Shao-iian 《Journal of Iron and Steel Research(International)》 SCIE EI CAS CSCD 2007年第4期6-10,48,共6页
A parameter perturbation for the unsteady-state heat-transfer characteristics of honeycomb regenerator is presented. It is limited to the cases where the storage matrix has a small wall thickness so that no temperatur... A parameter perturbation for the unsteady-state heat-transfer characteristics of honeycomb regenerator is presented. It is limited to the cases where the storage matrix has a small wall thickness so that no temperature variation in the matrix perpendicular to the flow direction is considered. Starting from a two-phase transient thermal model for the gas and storage matrix, an approximate solution for regenerator heat transfer process is derived using the multiple-scale method for the limiting case where the longitudinal heat conduction of solid matrix is far less than the convective heat transfer between the gas and the solid. The regenerator temperature profiles are expressed as Taylor series of the coefficient of solid heat conduction item in the model. The analytical validity is shown by comparing the perturbation solution with the experiment and the numerical solution. The results show that it is possible for the perturbation to improve the effectiveness and economics of thermal research on regenerators. 展开更多
关键词 honeycomb regenerator thermal process asymptotic analysis semi-analytic method
下载PDF
Segregation of Molten Salt on Chromizing in Thermal Diffusion Process 被引量:1
18
作者 王洪福 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第6期1189-1192,共4页
The segregation of thermal diffusion salt bath chromizing process was analyzed. The experimental chromizing ingredients were prepared by the four groups A, B, C, and D. In order to study the segregation status of this... The segregation of thermal diffusion salt bath chromizing process was analyzed. The experimental chromizing ingredients were prepared by the four groups A, B, C, and D. In order to study the segregation status of this case, the cooling molten salt in the crucible was removed by drilling from the heart core of molten salt. The core of molten salt was analyzed by X-ray fluorescence spectroscopy and XRD. Through the analysis, we can conclude that the Cr element deposited in the bottom was 4.51 times than the top. Chloride added to the molten salt will reduce segregation. Meantime we proposed some measures to overcome the segregation problem. 展开更多
关键词 SEGREGATION thermal diffusion process chromizing
下载PDF
Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics 被引量:2
19
作者 Zhaoxiang Zhang Fei Guo +2 位作者 Wei Song Xiaohong Jia Yuming Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期132-144,共13页
Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction ra... Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were considered.Two types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate,and two types of correction methods are provided.The model was explained and verified using published experimental data of different polymer thermal reaction systems,and its effectiveness and wide adaptability were confirmed.For the given kinetic model,only one parameter needs to be determined.The proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process. 展开更多
关键词 thermal reaction Polymer processing Reaction kinetics Mathematical modeling Empirical correction
下载PDF
Thermal recovery process of a backfilled open-pit in permafrost area at the Gulian strip coal mine in Northeast China 被引量:1
20
作者 GAO Shu-hui HE Rui-xia +3 位作者 JIN Hui-jun HUANG Ya-dong ZHANG Jian-ming LUO Dong-liang 《Journal of Mountain Science》 SCIE CSCD 2017年第11期2212-2229,共18页
Timely and proper backfilling of open-pits in strip coal-mines has been an effective measurement for the recovery of the hydrothermal regimes and ecological environment in permafrost regions. In this study, numerical ... Timely and proper backfilling of open-pits in strip coal-mines has been an effective measurement for the recovery of the hydrothermal regimes and ecological environment in permafrost regions. In this study, numerical simulations and statistical regressions were applied for analyzing the recovery processes of the backfill and its major influencing factors for the thermal equilibrium in recently backfilled open pits at the Gulian strip coalmine in Mo'he, Northeast China. Results show that the thermal recovery time of backfilled areas is positively correlated to the backfill depth(BD) of the soils, the backfilled soil temperature(BST), and the mean annual ground surface temperature(MAGST); meanwhile, climate warming can impact on thermal regimes of the backfill area. The impact of climate warming on ground temperature of the backfill will show up significantly in about 50 years afterbackfilling(BD at 10.0 and 20.0 m, BST at 20.0°C) under the climate warming scenario(CWS) of 0.025°C·year ^(-1). Grey-relation analyses show that the sensitivity of the backfill recovery time declines in the order of the BD, BST and MAGST. On the basis of the abovementioned studies, the layer-by-layer backfilling in cold seasons is advised for more effective and more rapid recovery of thermal regimes of the backfilled open-pits in cold regions. 展开更多
关键词 Coal-mine open-pit BACKFILL Numericalsimulation thermal recovery process SENSITIVITYANALYSIS Gulian STRIP coal mine
下载PDF
上一页 1 2 169 下一页 到第
使用帮助 返回顶部