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Effect of sintering temperature and holding time on structure and properties of Li_(1.5)Ga_(0.5)Ti_(1.5)(PO_4)_(3)electrolyte with fast ionic conductivity
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作者 Yin-yi LUO Hao-zhang LIANG +6 位作者 Ping ZHANG Lei HAN Qian ZHANG Li-dan LIU Zhi-wei LUO Tian-xiang NING An-xian LU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期2959-2971,共13页
Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects... Li1.5Ga0.5Ti1.5(PO4)3(LGTP)is recognized as a promising solid electrolyte material for lithium ions.In this work,LGTP solid electrolyte materials were prepared under different process conditions to explore the effects of sintering temperature and holding time on relative density,phase composition,microstructure,bulk conductivity,and total conductivity.In the impedance test under frequency of 1-10~6 Hz,the bulk conductivity of the samples increased with increasing sintering temperature,and the total conductivity first increased and then decreased.SEM results showed that the average grain size in the ceramics was controlled by the sintering temperature,which increased from(0.54±0.01)μm to(1.21±0.01)μm when the temperature changed from 750 to 950°C.The relative density of the ceramics increased and then decreased with increasing temperature as the porosity increased.The holding time had little effect on the grain size growth or sample density,but an extended holding time resulted in crack generation that served to reduce the conductivity of the solid electrolyte. 展开更多
关键词 sintering temperature holding time CONDUCTIVITY cracks solid-state electrolyte
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Characterization of Hydroxyapatite Extracted from Crab Shell Using the Hydrothermal Method with Varying Holding Times
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作者 Deni Fajar Fitriyana Rifky Ismail +2 位作者 Athanasius Priharyoto Bayuseno Januar Parlaungan Siregar Tezara Cionita 《Journal of Renewable Materials》 EI CAS 2024年第6期1145-1163,共19页
Hydroxyapatite(HA)is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties.Crab shells are usually disregarded as waste material despite their significant CaCO_... Hydroxyapatite(HA)is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties.Crab shells are usually disregarded as waste material despite their significant CaCO_(3) content,and have not been widely utilized in the synthesis of HA.This study aims to synthesize and analyze HA derived from crab shells using the hydrothermal method with different durations of holding time.This study utilized precipitated calcium carbonate(PCC)derived from crab shells.With a hydrothermal reactor set at 160℃ and varying holding times of 14(HA_14),16(HA_16),and 18(HA_18)h,a PCC and(NH4)2HPO4 mixture was used to synthesize HA.The synthesis results were analyzed using scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR),and X-ray diffraction(XRD)tests.This study has accomplished the synthesis of HA from crab shells.Nonetheless,the final product of synthesis still contained CaCO_(3) as an impurity.The prolonged hydrothermal holding time of 14 to 18 h resulted in a reduction of impurities while increasing the percentage of crystal weight and crystallite size of HA.Specimen CH_18 is the best-quality product generated in this study.This specimen produced HA with the highest percentage of crystal weight and crystallite size compared to the other specimens.Furthermore,specimen CH_18 exhibited the lowest concentration of impurities.The Ca/P ratio in this specimen was also the closest to 1.67.The Ca/P ratio,crystallite size,and crystal weight percentage of this specimen are 1.54,19.06 nm,and 99.1%,respectively. 展开更多
关键词 HYDROXYAPATITE crab shells CaCO_(3) HYDROTHERMAL holding time
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Application of a 2 Parameter Weibull Distribution in Modeling of State Holding Time in HIV/AIDS Transition Dynamics
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作者 Nahashon Mwirigi 《Open Journal of Modelling and Simulation》 2024年第4期130-158,共29页
This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Fai... This study investigates the application of the two-parameter Weibull distribution in modeling state holding times within HIV/AIDS progression dynamics. By comparing the performance of the Weibull-based Accelerated Failure Time (AFT) model, Cox Proportional Hazards model, and Survival model, we assess the effectiveness of these models in capturing survival rates across varying gender, age groups, and treatment categories. Simulated data was used to fit the models, with model identification criteria (AIC, BIC, and R2) applied for evaluation. Results indicate that the AFT model is particularly sensitive to interaction terms, showing significant effects for older age groups (50 - 60 years) and treatment interaction, while the Cox model provides a more stable fit across all age groups. The Survival model displayed variability, with its performance diminishing when interaction terms were introduced, particularly in older age groups. Overall, while the AFT model captures the complexities of interactions in the data, the Cox model’s stability suggests it may be better suited for general analyses without strong interaction effects. The findings highlight the importance of model selection in survival analysis, especially in complex disease progression scenarios like HIV/AIDS. 展开更多
关键词 Weibull Distribution AFT Model Cox Proportional Hazards HIV/AIDS State holding Time Survival Analysis
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Dust-Holding Capacity and Bio-Chemical Changes of Plant Species Growing in an Around Opencast Mining Area of Bundelkhand Region of Uttar Pradesh, India
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作者 Priyanka Singh Amit Pal 《American Journal of Plant Sciences》 CAS 2024年第8期677-698,共22页
The present study has been carried out on a total of 50 available plant species to assess their dust-capturing capacity and biochemical performances in and around open cast granite mine areas of Jhansi district and Bu... The present study has been carried out on a total of 50 available plant species to assess their dust-capturing capacity and biochemical performances in and around open cast granite mine areas of Jhansi district and Bundelkhand University campus treated as control site. Plant species existing under a polluted environment for a long time may be considered as potentially resistant species and recommended for green belt design in mining areas, especially to cope with dust pollution. Results showed the pollution level, especially of mining-originated dust particles holding capacity of leaves and effects of different biochemical parameters (Total Chlorophyll, Protein and Carotenoid) of existing plant species both from mining areas as well as from Bundelkhand University campus. Based on their performances, Tectona grandis L., Ficus hispida L., Calotropis procera Aiton., Butea monosperma Lam. and Ficus benghalensis L., etc. are highly tolerant species while Ficus infectoria L., Artocarpus heterophyllus Lam., Ipomoea purpurea L., Allianthus excelsa Roxb. and Bauhinia variegata L. are intermediate tolerant species. T. grandis had shown the highest dust-holding capacity (2.566 ± 0.0004 mg/cm2) whereas Albizia procera (0.018 ± 0.0002 mg/cm2) was found to be the lowest dust-holding capacity. Our findings also showed that the T. grandis and F. hispida have significant dust deposition with minimal effect of dust on their leaf chlorophyll (17.447 ± 0.019 mg/g and 14.703 ± 0.201 mg/g), protein (0.699 ± 0.001 mg/g and 0.604 ± 0.002 mg/g) and carotenoid (0.372 ± 0.003 mg/g and 0.354 ± 0.003 mg/g) content respectively among all selected plant species. Therefore, in the present investigation, plant species with high tolerance to high dust-holding capacity on their leaf surfaces are preferable for green corridors as open cast granite mines and their adjacent areas. 展开更多
关键词 Bundelkhand Region Biochemical Changes Dust-holding Capacity Chlorophyll Content Open Cast Granite Mining
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Nail Holding Performance of Self-Tapping Screws on Masson Pine and Chinese Fir Dimension Lumbers
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作者 De Li Bengang Zhang +7 位作者 Yuan Tu Guoming Xiao Meifen Tian Xiaoxue Xu Xiao Zhong Qiaoyan Zhang Zhigang Wu Jiankun Liang 《Journal of Renewable Materials》 EI 2023年第10期3725-3738,共14页
Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects o... Screw connection is a type most commonly applied to timber structures.As important commercial tree species in China,Masson pine and Chinese fir have the potential to prepare wood structures.In this study,the effects of the diameter of the self-tapping screw and the guiding bores on the nail holding performance on different sections of Masson pine and Chinese fir dimension lumbers were mainly explored.The results showed that:(1)The nail holding strength of the tangential section was the maximum,followed by that of the radial section,and that of the cross section was the minimum.(2)The nail holding strength of Masson pine was higher than that of Chinese fir.(3)The nail holding strength grew with the increase in the diameter of self-tapping screws,but a large diameter would lead to plastic cracking of the timber,thus further affecting the nail holding strength.Masson pine and Chinese fir reached the maximum nail holding strength when the diameter of self-tapping screws was 3.5 mm.(4)Under a large diameter of screws,prefabricated guiding bores could mitigate timber cracking and improve its nail holding strength.(5)Prefabricated guiding bores were more necessary for the screw connection of Masson pine.The results obtained could provide a scientific basis for the screw connection design of Masson pine and Chinese fir timber structures. 展开更多
关键词 Masson pine Chinese fir self-tapping screws nail holding performance
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Inter-Fraction Analysis of One Week Hypo-Fractionation of Deep Inspiration Breath Hold (DIBH) Technique for Left Sided Breast Cancer Radiation Treatment
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作者 Ntombela N. Lethukuthula Mathuthu Manny Nyathi Mpumelelo 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2024年第3期41-52,共12页
The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatme... The aim of this study was to investigate the inter-fraction variations, patient comfort and knowledge at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). The differences in set-up that occurred between treatment sessions for the left sided breast patients were observed and recorded. Measurements of routine set-up variation for 24 patients were performed by matching the cone beam computed tomography (CBCT) and the planning computed tomography (CT). Scans of all five fractions per patient were used to quantify the setup variations with standard deviation (SD) in all the three directions (anterior posterior, left right, and superior inferior). The patients DIBH comfort and knowledge was also evaluated. The average translational errors for the anterior posterior (AP, z), left-right (LR, x), and Superior-inferior (SI, y) directions were 0.40 cm, 0.40 cm, and 0.40 cm, respectively. The translation variation of the three directions showed statistical significance (P < 0.05). On comfort and knowledge investigation, among all participants, 80% moderately agreed that the therapist’s instructions for operating the deep inspiration breath hold (DIBH) technique were easy to understand, and 63.33% indicated that their comfort with the DIBH technique was neutral or average. The inter-fraction variations in patients with left-sided breast cancer were qualitatively analyzed. Significant shifts between CBCT and planning CT images were observed. The daily treatment verification could assist accurate dose delivery. 展开更多
关键词 Breast Cancer Deep Inspiration Breath hold Hypo-Fractionation Inter-Fraction
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Effects of Addition of Bee Pollen on Water Holding Capacity of Pork
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作者 王启发 王中才 《Animal Husbandry and Feed Science》 CAS 2009年第4期18-20,共3页
[ Objective] To explore the effects of different proportion of bee pollen on the water holding capacity of pork in Duroc Landrace x Yorkshire growing-finishing pigs in order to determine the optimal proportion. [ Met... [ Objective] To explore the effects of different proportion of bee pollen on the water holding capacity of pork in Duroc Landrace x Yorkshire growing-finishing pigs in order to determine the optimal proportion. [ Method] A total of 80 Duroc x Landrace x Yorkshire growing-finishing pigs, weighing (10.0 ± 1.0) kg, were randomly divided into five groups. The experimental period was 120 d including the 5-day pre-feecling period. The corn-soybean meal was not replaced during the whole period. All pigs had free access to feed and water. The pigs were fasting for 24 h but not prohibited from feed before the beginning. Group I was the control group reared with the diet not supplemented bee pollen. The pigs in group II, III ,IV and V were reared with the diet supplemented bee pollen at the concentration of 1%, 3%, 5% and 7%, respectively. After slaughtering, eye muscle was used for determination of water holding capacity through fast filter paper method, drip loss method, cooking loss method and Na- pole yield determination method. [ Resultl With the increase of the proportion of bee pollen, the water holding capacity of pork was first good and then poor. The addition of bee pollen at the concentration of 5% significantly reduced the drip loss of pork and the water holding capacity which was detected by fast filter paper method, but the cooking loss and Napole yield were not significantly influenced. [ Condmion] The bee pollen can effectively improve the water holding capacity of pork in Duroc x Landrace x Yorkshire growing-finishing pigs, and the optimal proportion is 5%. 展开更多
关键词 Bee pollen Water holding capacity Fast filter paper method Drip loss method Cooking loss method Napole yield determinationmethod
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Optimization of Holding Temperature and Holding Thickness for Controlled Rolling on Plate Mill 被引量:3
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作者 HU Xian-lei ZHAO Zhong WANG Jun WANG Zhao-dong LIU Xiang-hua WANG Guo-dong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第3期21-25,共5页
Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase co... Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase controlled rolling on plate mill was presented and its feature is as follows: (1) Determination of holding thickness can be automatically obtained based on the influence of mill safety limits, tracking zone length and holding time on holding thickness; (2) Determination of holding temperature can be automatically obtained and the holding time can be reduced as much as possible; (3) Algorithm can modify the holding temperature and thickness depending on slab size and product size. 展开更多
关键词 PLATE two-phase controlled rolling pass schedule holding temperature holding thickness
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Effects of Calcining Temperature and Holding Time on the Synthesis of Aluminum Titanate 被引量:8
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作者 沈阳 阮玉忠 于岩 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第2期228-234,共7页
We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holdin... We aim in this research at synthesizing high-purity aluminium titanate with sludge from the aluminium profile factory by shock cooling method, and mainly discuss the effect of calcining reaction temperature and holding time on crystalline, microstructure and content of aluminum titanate materials to determine the preferred calcining temperature and holding time. XRD and SEM methods were utilized to characterize the crystalline and microstructure of each specimen, Rietveld Quantification software was used for the determination of different crystalline contents of specimens, and Philips plus software was applied to determine the cell parameters of aluminium titanate in different specimens. According to the experimental results, preferred calcining temperature is determined as 1400℃ and preferred holding time is 2 h, at which the grains of aluminum titanate grow completely and the purity of aluminum titanate is 97.2wt%. 展开更多
关键词 calcining temperature holding time AL2TIO5 crystalline structure MICROSTRUCTURE
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Effect of holding pressure on density and cooling rate of cast Al-Si alloy during additive pressure casting 被引量:4
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作者 Zhen Fan Wei Song +4 位作者 Hua-rui Zhang Bao-sheng Zhou Xiao-yan Wu Li-na Jia Hu Zhang 《China Foundry》 SCIE 2019年第6期363-370,共8页
The cast Al-Si alloy was fabricated using the Additive Pressure Casting(APC)method.The effects of holding pressure from 50 to 400 k Pa on the density,cooling rate,and mechanical properties of the alloy,and the corresp... The cast Al-Si alloy was fabricated using the Additive Pressure Casting(APC)method.The effects of holding pressure from 50 to 400 k Pa on the density,cooling rate,and mechanical properties of the alloy,and the corresponding mechanism were discussed.The results indicate that the application of high holding pressure(300 k Pa)enhances the feeding ability of the alloy,leading to an increase of the density.Meanwhile,the cooling rate of the alloy is increased by 100%.In addition,the tensile testing results show that the increase of holding pressure from 50 to 300 k Pa improves the tensile strength and elongation of the alloy by 6.2%and 81.3%,respectively.However,excessive holding pressure(400 k Pa)might lower the density and cooling rate of the alloy due to the feeding channels being blocked. 展开更多
关键词 holding PRESSURE cast Al-Si alloy DENSITY cooling rate mechanical properties ADDITIVE PRESSURE CASTING
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Effect of Holding Time on the Microstructure and Mechanical Properties of Dual-Phase Steel during Intercritical Annealing 被引量:3
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作者 李壮 WU Di +3 位作者 Lü Wei YU Huanhuan SHAO Zhenyao LUO Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第1期156-161,共6页
Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820℃ were ad... Continuous annealing simulation tests were conducted by using a continuous annealing thermomechanical simulator. Holding times of 5, 60, 180, and 480 seconds for an intercritical annealing temperature of 820℃ were adopted to investigate the evolution of the mierostructure and mechanical properties of ferrite-bainite dual-phase steel. The ferrite-bainite dual-phase steel was characterized by high strength and low yield ratio due to the presence of the constituents (polygonal ferrite, bainite, martensite and retained austenite) of the steel microstructure. Specimen 3 exhibits the highest value of A50 (7.67%) and a product of Rm × A50 (10453MPa%) after a 180s holding. This is likely attributed to the presence of a C-enriched retained anstenite in the microstructure. And the effect of martensite islands and carbide precipitate is thought to be able to contribute in strengthening the present steel. It is expected that equilibrium of anstenite fraction would be reached for reasonable intercritical holding period, regardless of the heating temperature. The results suggest that long increasing holding times may not be needed because the major phase of the microstructure does not change very significantly. It is favorable for industrial production of DP steels to shorten holding times. Key words: ferrite-bainite dual-phase steel; holding time; martensite islands; mechanical properties 展开更多
关键词 ferrite-bainite dual-phase steel holding time maxtensite islands mechanical properties
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An improved GGNMOS triggered SCR for high holding voltage ESD protection applications 被引量:2
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作者 张帅 董树荣 +3 位作者 吴晓京 曾杰 钟雷 吴健 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期591-593,共3页
Developing an electrostatic discharge(ESD) protection device with a better latch-up immunity has been a challenging issue for the nanometer complementary metal-oxide semiconductor(CMOS) technology. In this work, a... Developing an electrostatic discharge(ESD) protection device with a better latch-up immunity has been a challenging issue for the nanometer complementary metal-oxide semiconductor(CMOS) technology. In this work, an improved grounded-gate N-channel metal-oxide semiconductor(GGNMOS) transistor triggered silicon-controlled rectifier(SCR)structure, named GGSCR, is proposed for high holding voltage ESD protection applications. The GGSCR demonstrates a double snapback behavior as a result of progressive trigger-on of the GGNMOS and SCR. The double snapback makes the holding voltage increase from 3.43 V to 6.25 V as compared with the conventional low-voltage SCR. The TCAD simulations are carried out to verify the modes of operation of the device. 展开更多
关键词 electrostatic discharge holding voltage GGSCR
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Microstructure evolution of isothermal holding treatment during melt solidification of Ti-6Al-4V alloy
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作者 张守银 李金山 +3 位作者 寇宏超 杨劼人 杨光 王军 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第4期1091-1096,共6页
Effect of isothermal holding treatment in the solidification process on the microstructure of Ti-6Al-4V alloy was studied by temperature controlled induced melting apparatus. The result shows that with isothermal hold... Effect of isothermal holding treatment in the solidification process on the microstructure of Ti-6Al-4V alloy was studied by temperature controlled induced melting apparatus. The result shows that with isothermal holding treatment above the β transus temperature during solidification, the colony structure consisting of parallel lamellae was obtained. While the isothermal holding treatment was set at 960 °C, a unique bi-modal microstructure consisting of coarse primary α and fine secondary lamellar α was obtained. The primary lamellar α tended to break into several pieces, globularize and present equiaxed morphology. The formation mechanism of the equiaxed α can be explained with the atom immigration, high density dislocations, combined action with the interface tension of formed α phase during the isothermal holding treatment. After the isothermal holding, the retained β matrix transformed into fine lamellar α, thus, bi-modal microstructure was acquired. Compared with the lamellar structure, the grain boundary α presented discontinuously and cannot be distinguished from the primary α lamellae easily. The size of colonies α was greatly decreased. The microstructure tended to be much more homogeneous in the whole section of the samples. 展开更多
关键词 titanium alloy isothermal holding treatment bi-modal structure grain boundaries equiaxed α phase
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Numerical simulation of aluminum holding furnace with fluid-solid coupled heat transfer 被引量:8
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作者 周乃君 周善红 +1 位作者 张家奇 潘青林 《Journal of Central South University》 SCIE EI CAS 2010年第6期1389-1394,共6页
To predict three-dimensional temperature distribution of molten aluminum and its influencing factors inside an industrial aluminum holding furnace,a fluid-solid coupled method was presented.The fluid-solid coupled mat... To predict three-dimensional temperature distribution of molten aluminum and its influencing factors inside an industrial aluminum holding furnace,a fluid-solid coupled method was presented.The fluid-solid coupled mathematics models of aluminum holding furnace in the premixed combustion processing were established based on mass conservation,moment conservation,momentum conservation,energy conservation and chemistry species conservation.Computational results agree well with the test data of the typical condition.The maximum combustion temperature is 1 850 K.The average temperature of the molten aluminum is 1 158 K,and the maximum temperature difference is about 240 K.The average temperature increases 0.3 ℃ while the temperature of combustion air increases 1 ℃.The optimal excess air ratio is 1.25-1.30. 展开更多
关键词 aluminum holding furnace COMBUSTION heat transfer fluid-solid coupled numerical simulation
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Effect of melt holding on morphological evolution and sedimentation behavior of iron-rich intermetallic phases in Al-Si-Fe-Mn-Mg alloy 被引量:7
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作者 Dong-fu SONG Shun-cheng WANG +5 位作者 Yu-liang ZHAO Shu-hong LIU Yong DU Yue-hua KANG Zhi WANG Wei-wen ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第1期1-13,共13页
The effect of the melt holding temperature on the morphological evolution and sedimentation behavior of iron-rich intermetallics in Al-7.0 Si-1.0 Fe-1.2 Mn-0.25 Mg alloy was investigated using an optical microscope,sc... The effect of the melt holding temperature on the morphological evolution and sedimentation behavior of iron-rich intermetallics in Al-7.0 Si-1.0 Fe-1.2 Mn-0.25 Mg alloy was investigated using an optical microscope,scanning electron microscope and differential thermal analyzer.The results show that as the holding temperature decreases,the morphologies of the primary iron-rich phase in matrix change from star-like to polygonal,and the number of the primary phases gradually decreases and disappears at 615°C.Finally,the Chinese script phases with small size,high compact and uniform distribution are obtained.In contrast,the primary iron-rich phases in slag transform into a coarser polygonal shape with lower roundness,and some of them have hollow structures.Furthermore,the area fraction of intermetallics and Fe content in the matrix decrease gradually due to the formation and growth of sludge and subsequent natural sedimentation during melt holding.With the decrease of holding temperature,the main factors hindering the settlement of the primary phases are morphology,size,and density in turn. 展开更多
关键词 Al-Si alloy melt holding iron-rich intermetallic phases morphological evolution sedimentation behaviour
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Grain refinement of AZ91D alloy by intensive melt shearing and its persistence after remelting and isothermal holding 被引量:4
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作者 Zuo Yubo Fan Zhongyun Cui Jianzhong 《China Foundry》 SCIE CAS 2013年第1期39-42,共4页
Intensive melt shearing has a significant grain refining effect on some light alloys.However,the persistence of the grain refining effect during isothermal holding and remelting is still unclear,although it is very im... Intensive melt shearing has a significant grain refining effect on some light alloys.However,the persistence of the grain refining effect during isothermal holding and remelting is still unclear,although it is very important for the practical application.In this study,intensive melt shearing was achieved in a twin-screw mechanism to investigate its grain refining effect on AZ91D magnesium alloy.The refinement mechanism was discussed and the persistence of grain refinement after remelting and isothermal holding was also studied.A Zeiss imaging system with polarized light was used for quantitative measurement of grain size.The results show that the intensive melt shearing has a significant grain refining effect on AZ91D magnesium alloy.With the application of intensive melt shearing,the grain size of AZ91D magnesium alloy can be reduced from 530 μm(for a typical as-cast microstructure) to 170 μm,which is about 70% size reduction.The grain refinement achieved by the intensive melt shearing can be partially kept after isothermal holding and remelting.It is believed that the refinement effect was mainly due to the finer and well dispersed oxide particles formed by high intensive shearing.The smaller size of oxide particles and their slow motion velocity in the sheared melt could make important contributions to the remained grain refinement. 展开更多
关键词 magnesium alloy microstructure intensive melt shearing REMELTING isothermal holding
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Water Holding Characteristics of Coarse Woody Debris of Abies fabri Forest on the East Slope of Tibet Sygera Mountain 被引量:1
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作者 Han Yanying Wei Liping +3 位作者 Chen Chen Du Jiahao Lei Yafang Ye Yanhui 《Meteorological and Environmental Research》 CAS 2018年第5期11-14,18,共5页
Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD i... Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD in subalpine forest of southeast Tibet,CWD reserve of primitive A. fabri forest in Sygera Mountain was investigated by sample plot method,and water absorption and storage capacity of CWD was studied by using soaking method. The results showed that decay grade was positively related to water storage potential,that is to say,the higher the decay grade,the larger the water storage potential. Saturated water holding capacity,saturated water holding rate,effective water holding capacity and effective water holding rate of A. fabri CWD all rose with decay grade increased,and the order was Ⅴ>Ⅳ>Ⅲ>Ⅱ>Ⅰ. CWD reserve was 51.555 t/hm^2,and the maximum water storage capacity was 71.601 t/hm^2,while effective water storage capacity was 60.861 t/hm2,which was equivalent to 6.086 mm of rainfall. 展开更多
关键词 Sygera MOUNTAIN A.fabri forest CWD WATER holding CHARACTERISTICS
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Combustion and energy balance of aluminum holding furnace with bottom porous brick purging system 被引量:3
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作者 ZHANG Jia-qi ZHOU Nai-jun ZHOU Shan-hong 《Journal of Central South University》 SCIE EI CAS 2012年第1期200-205,共6页
For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and... For acquiring the details in aluminum holding furnace with bottom porous brick purging system,efforts were performed to try to find out the potential optimal operation schemes.By adopting transient analysis scheme and constant boundary temperature,combustion in the furnace was investigated numerically using computational fluid dynamics(CFD).The predicted gas temperature shows good agreement with the measured results,and the predicted energy distribution of the furnace is consistent with that obtained from energy balance experiment,which confirms the reliability of the numerical solution.The results show that as the fuel-air mixture temperature rises up from 300 K to 500 K,the energy utilization of the furnace could increase from 34.55% to 37.14%.However,as the excess air coefficient increases from 1.0 to 1.4,energy utilization drops from 34.55% to 29.56%.Increasing the combustion temperature is the most effective way to improve the energy efficiency of the furnace.High reactant temperature and medium excess air coefficient are recommended for high operation performance,and keeping the furnace jamb sealed well for avoiding leakage has to be emphasized. 展开更多
关键词 aluminum holding furnace COMBUSTION FLOW numerical study computational fluid dynamics
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An Inventory Model for Deteriorating Items with Generalised Exponential Decreasing Demand, Constant Holding Cost and Time-Varying Deterioration Rate 被引量:2
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作者 Isiyaku Aliyu Babangida Sani 《American Journal of Operations Research》 2018年第1期1-16,共16页
In this present paper, an inventory model with a generalised exponential decreasing demand is considered. A numerical example is used to illustrate the application of the model. Sensitivity analysis of the optimal sol... In this present paper, an inventory model with a generalised exponential decreasing demand is considered. A numerical example is used to illustrate the application of the model. Sensitivity analysis of the optimal solution with respect to various parameters is carried out to see the effect of parameter changes on the solution. 展开更多
关键词 Linear DETERIORATION Generalize EXPONENTIAL DECREASING DEMAND Inventory CONSTANT holding Cost
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Numerical simulation and combination optimization of aluminum holding furnace linings based on simulated annealing 被引量:2
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作者 王计敏 兰申 +2 位作者 陈涛 李文科 楚化强 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第6期880-889,共10页
To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simula... To reduce heat loss and save cost, a combination decision model of reverb aluminum holding furnace linings in aluminum casting industry was established based on economic thickness method, and was resolved using simulated annealing. Meanwhile, a three-dimensional mathematical model of aluminum holding furnace linings was developed and integrated with user-defined heat load distribution regime model. The optimal combination was as follows: side wall with 80 mm alumino-silicate fiber felts, 232 mm diatomite brick and 116 mm chamotte brick; top wall with 50 mm clay castables, 110 mm alumino-silicate fiber felts and 200 mm refractory concrete;and bottom wall with 232 mm high-alumina brick, 60 mm clay castables and 68 mm diatomite brick. Lining temperature from high to low was successively bottom wall, side wall, and top wall. Lining temperature gradient in increasing order of magnitude was refractory layer and insulation layer. It was indicated that the results of combination optimization of aluminum holding furnace linings were valid and feasible, and its thermo-physical mechanism and cost characteristics were reasonably revealed. 展开更多
关键词 Aluminum holding furnace linings Reaction engineering Transport processes Numerical simulation Combination optimization Simulated annealing
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