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三藩之乱期间琉球王国的外交抉择——以《华夷变态》的记载为中心
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作者 陈波 《元史及民族与边疆研究集刊》 CSSCI 2016年第2期103-114,共12页
清初三藩之乱的发生,造成东亚地缘政治格局的大震荡.经历了明末萨摩藩入侵之后的琉球王国,突然面临极其复杂的外交抉择.当时琉球的内政外交皆处于日本的严密监视之下,同时又与清朝缔结了宗藩关系,但是清琉之间的宗藩关系因台湾郑氏政权... 清初三藩之乱的发生,造成东亚地缘政治格局的大震荡.经历了明末萨摩藩入侵之后的琉球王国,突然面临极其复杂的外交抉择.当时琉球的内政外交皆处于日本的严密监视之下,同时又与清朝缔结了宗藩关系,但是清琉之间的宗藩关系因台湾郑氏政权陆梁滨海而并不稳固.郑氏兵船在三藩之乱爆发前夜的康熙九年(1670)和十二年(1673),曾两度攻击琉球贡船,引起台湾郑氏政权与日本及琉球关系紧张,也使得琉球对于三藩之乱的态度,持有相当程度的保留.1674年三藩之乱爆发后,琉球使团成员大部被羁留福州,对于耿精忠政权有近距离的观察.关于上述历史过程,日本海外情报集《华夷变态》一书有比较完整的呈现.本文试图结合中文与日文史料,揭示作为弱国的琉球在三藩之乱期间如何周旋于地域强权之间以图生存的外交努力. 展开更多
关键词 三藩之乱 琉球贡船 华夷
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Improved AVOA based on LSSVM for wind power prediction
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作者 ZHANG Zhonglin WEI Fan +1 位作者 YAN Guanghui MA Haiyun 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第3期344-359,共16页
Improving the prediction accuracy of wind power is an effective means to reduce the impact of wind power on power grid.Therefore,we proposed an improved African vulture optimization algorithm(AVOA)to realize the predi... Improving the prediction accuracy of wind power is an effective means to reduce the impact of wind power on power grid.Therefore,we proposed an improved African vulture optimization algorithm(AVOA)to realize the prediction model of multi-objective optimization least squares support vector machine(LSSVM).Firstly,the original wind power time series was decomposed into a certain number of intrinsic modal components(IMFs)using variational modal decomposition(VMD).Secondly,random numbers in population initialization were replaced by Tent chaotic mapping,multi-objective LSSVM optimization was introduced by AVOA improved by elitist non-dominated sorting and crowding operator,and then each component was predicted.Finally,Tent multi-objective AVOA-LSSVM(TMOALSSVM)method was used to sum each component to obtain the final prediction result.The simulation results show that the improved AVOA based on Tent chaotic mapping,the improved non-dominated sorting algorithm with elite strategy,and the improved crowding operator are the optimal models for single-objective and multi-objective prediction.Among them,TMOALSSVM model has the smallest average error of stroke power values in four seasons,which are 0.0694,0.0545 and 0.0211,respectively.The average value of DS statistics in the four seasons is 0.9902,and the statistical value is the largest.The proposed model effectively predicts four seasons of wind power values on lateral and longitudinal precision,and faster and more accurately finds the optimal solution on the current solution space sets,which proves that the method has a certain scientific significance in the development of wind power prediction technology. 展开更多
关键词 African vulture optimization algorithm(AVOA) least squares support vector machine(LSSVM) variational mode decomposition(VMD) multi-objective prediction wind power
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Slope displacement prediction based on multisource domain transfer learning for insufficient sample data
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作者 Zheng Hai-Qing Hu Lin-Ni +2 位作者 Sun Xiao-Yun Zhang Yu Jin Shen-Yi 《Applied Geophysics》 SCIE CSCD 2024年第3期496-504,618,共10页
Accurate displacement prediction is critical for the early warning of landslides.The complexity of the coupling relationship between multiple influencing factors and displacement makes the accurate prediction of displ... Accurate displacement prediction is critical for the early warning of landslides.The complexity of the coupling relationship between multiple influencing factors and displacement makes the accurate prediction of displacement difficult.Moreover,in engineering practice,insufficient monitoring data limit the performance of prediction models.To alleviate this problem,a displacement prediction method based on multisource domain transfer learning,which helps accurately predict data in the target domain through the knowledge of one or more source domains,is proposed.First,an optimized variational mode decomposition model based on the minimum sample entropy is used to decompose the cumulative displacement into the trend,periodic,and stochastic components.The trend component is predicted by an autoregressive model,and the periodic component is predicted by the long short-term memory.For the stochastic component,because it is affected by uncertainties,it is predicted by a combination of a Wasserstein generative adversarial network and multisource domain transfer learning for improved prediction accuracy.Considering a real mine slope as a case study,the proposed prediction method was validated.Therefore,this study provides new insights that can be applied to scenarios lacking sample data. 展开更多
关键词 slope displacement multisource domain transfer learning(MDTL) variational mode decomposition(VMD) generative adversarial network(GAN) Wasserstein-GAN
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Boehmeria nivea var. strigosa (Urticaceae), a new variety from Southwest China 被引量:1
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作者 ZHAO Ying Richard I.MILNE +2 位作者 LI Zhipeng Amos KIPKOECH WU Zengyuan 《广西植物》 CAS CSCD 北大核心 2024年第9期1617-1624,I0001-I0006,共14页
Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly charact... Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly characterized by its green abaxial leaf blade,partly connate stipules,and densely patent strigose hairs on stems and potioles.The phylogenetic analysis based on rbc L,nrDNA and rbc L+nrDNA datasets,revealed that all individuals of B.nivea var.strigosa formed a monophyletic group.The conservation status of B.nivea var.strigosa is assessed as“Near Threatened”(NT)according to IUCN evaluation criteria.The discovery of this new variety is not only crucial for the taxonomy of ramie,but also provides reference for the exploration and utilization of ramie. 展开更多
关键词 Boehmeria nivea MORPHOLOGY molecular phylogeny new variety Southwest China YUNNAN
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A comprehensive review of carbon sequestration of seagrass in China from 2013
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作者 HUANG Xiaotong 《Marine Science Bulletin》 2024年第1期31-41,共11页
Seagrass is not only known for its ecological role,but also for its high capacity on the carbon sequestration.Although the area of seagrass meadows was less than 0.2%of the world’s oceans,the yearly organic carbon bu... Seagrass is not only known for its ecological role,but also for its high capacity on the carbon sequestration.Although the area of seagrass meadows was less than 0.2%of the world’s oceans,the yearly organic carbon burial of seagrass reached 10%of that in the ocean.Anthropogenic activities in the past two decades and the climate change have led to a significant decrease of seagrass meadow.Since seagrass is widely distributed along the coastline of China,it is necessary to put more efforts on the seagrass conservation and restoration,which will consequently be a suitable nature based solution for mitigating the climate change.This paper provides a comprehensive review on the following five aspects:1)the seagrass distribution in China;2)the role that seagrass plays in the climate mitigation;3)carbon sequestration of seagrass in China;4)loss of seagrass habitats and 5)the restoration of seagrass habitat in China since 2013.Current research gap and prospective research direction were also pointed out in this study. 展开更多
关键词 SEAGRASS carbon sequestration climate mitigation RESTORATION DISTRIBUTION ecological role
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Pricing Catastrophe Options with Credit Risk in a Regime-Switching Model
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作者 XU Yajuan WANG Guojing 《应用概率统计》 CSCD 北大核心 2024年第4期572-587,共16页
In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space... In this paper,we consider the price of catastrophe options with credit risk in a regime-switching model.We assume that the macroeconomic states are described by a continuous-time Markov chain with a finite state space.By using the measure change technique,we derive the price expressions of catastrophe put options.Moreover,we conduct some numerical analysis to demonstrate how the parameters of the model affect the price of the catastrophe put option. 展开更多
关键词 PRICING catastrophe option credit risk REGIME-SWITCHING measure change
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Shear mechanical properties and frictional sliding responses of rough joint surfaces under dynamic normal displacement conditions
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作者 ZHU Qiang YIN Qian +9 位作者 TAO Zhi-gang HE Man-chao ZHENG Bo-wen JING Hong-wen REN Shu-lin ZHANG Qiang MENG Bo BAI Dong-feng WU Sai-sai WU Jiang-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2393-2410,共18页
A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating... A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating geological disasters.This study conducted shear experiments on rough rock joints under displacement-controlled dynamic normal loads,investigating the shear behaviors of joints across varying initial normal loads,normal loading frequencies,and normal loading amplitudes.Experimental results showed that the peak/valley shear force values increased with initial normal loads and normal loading frequencies but showed an initial increase followed by a decrease with normal loading amplitudes.Dynamic normal loading can either increase or decrease shear strength,while this study demonstrates that higher frequencies lead to enhanced friction.Increased initial normal loading and normal loading frequency result in a gradual decrease in joint roughness coefficient(JRC)values of joint surfaces after shearing.Positive correlations existed between frictional energy dissipation and peak shear forces,while post-shear joint surface roughness exhibited a negative correlation with peak shear forces through linear regression analysis.This study contributes to a better understanding of the sliding responses and shear mechanical characteristics of rock joints under dynamic disturbances. 展开更多
关键词 dynamic normal displacement shear strength variations phase lag phenomenon STICK-SLIP
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Competitive Strategies of Two Species of Co-occuring Tadpoles 被引量:3
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作者 张晋东 熊晔 +3 位作者 傅之屏 李玉杰 戴强 王跃招 《Zoological Research》 CAS CSCD 北大核心 2007年第1期41-46,共6页
We examined the competitive ability of larval toads (Bufo gargarizans ) and frogs (Rana kukunoris ) which co-occur in natural pools in the Jiuzhaigou Nature Reserve. We measured the activity level, growth rate, ma... We examined the competitive ability of larval toads (Bufo gargarizans ) and frogs (Rana kukunoris ) which co-occur in natural pools in the Jiuzhaigou Nature Reserve. We measured the activity level, growth rate, mass at metamorphosis and larval period in a laboratory experiment. Tadpoles of B. gargarizans were significantly more active when food was abundant than scarce, while there was no significant difference in the activity of R. kukunoris tadpoles at different food levels. At low food availability, mass at metamorphosis and growth rate of R. kukunoris were significantly increased in the presence of B. gargarizans, whereas the presence of R. kukunoris had no significant effect on the mass and growth rate of B. gargarizans. In all treatments, the larval period of B. gargarizans at low food availability was the shortest. These results suggest that B. gargarizans can adapt to different food levels by changing their activity rate. At high food level, B. gargarizans increased activity to gain more food. At low food level, B. gargarizans decreased activity and achieved early metamorphosis. However, when food resources were limited, R. kukunoris could gain more food than B.gargarizans . 展开更多
关键词 Activity level Mass at metamorphosis Bufo gargarizans Rana kukunoris Interspecific competition
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Flow softening behavior and microstructure evolution of Al-5Zn-2Mg aluminum alloy during dynamic recovery 被引量:13
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作者 李落星 王冠 +1 位作者 刘杰 姚再起 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第1期42-48,共7页
The flow stress behavior and microstructure development of Al-5Zn-2Mg (7005) aluminum alloy were studied by hot compression tests at deformation temperatures between 300-500 &#176;C and strain rates between 0.05-50... The flow stress behavior and microstructure development of Al-5Zn-2Mg (7005) aluminum alloy were studied by hot compression tests at deformation temperatures between 300-500 &#176;C and strain rates between 0.05-50 s-1. The deformed structures of the samples were observed by optical microscopy (OM), transmission electron microscopy (TEM) and electron backscattering diffraction (EBSD) analysis. The calculated activation energy is 147 kJ/mol, which is very close to the activation energy for lattice self-diffusion in aluminum (142 kJ/mol). Dynamic recovery is the dominant restoration mechanism during the deformation. At high strain rate of 50 s-1, temperature rise due to deformation heating leads to a significant flow softening. Microstructure observations indicated that the remaining softening after deformation heating correction at high strain rate and the softening observed at high temperature are associated with grain coarsening induced by grain boundary migration during dynamic recovery process. 展开更多
关键词 7005 aluminum alloy DEFORMATION dynamic recovery flow softening microstructure evolution
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Eco-environment Evolution and Its Sustainable Development Strategies in Western China 被引量:7
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作者 张巧显 柯兵 +2 位作者 刘昕 刘国华 吴钢 《Agricultural Science & Technology》 CAS 2010年第1期176-181,共6页
Natural condition in Western China is relatively poor and regional economy level is low. The ecological environment has been seriously damaged by population growth and over-exploitation of natural resources. It is ver... Natural condition in Western China is relatively poor and regional economy level is low. The ecological environment has been seriously damaged by population growth and over-exploitation of natural resources. It is very important for coordinating the regional development and safeguarding ecological security to discuss the eco-environment evolution trend and its sustainable development strategies in Western China. Based on analyzing documents and relative research,the changes of main ecological and environmental problems in the western region,such as degradation of forest and grassland ecosystems,shrinkage of wetland,desertification,water and soil erosion,etc. were synthetically discussed. Then,according to the development trend,some countermeasures for eco-environment protection and rehabilitation and sustainable development were proposed. 展开更多
关键词 Eco-environment evolution Ecological degradation Sustainable development Western China
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Modeling of strain hardening and dynamic recrystallization of ZK60 magnesium alloy during hot deformation 被引量:11
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作者 何运斌 潘清林 +3 位作者 陈琴 张志野 刘晓艳 李文斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期246-254,共9页
The flow stress behavior of ZK60 alloy at elevated temperature was investigated. The strain hardening and dynamic recrystallization of the alloy were modeled by Kocks-Meching model and Avrami equation, respectively. A... The flow stress behavior of ZK60 alloy at elevated temperature was investigated. The strain hardening and dynamic recrystallization of the alloy were modeled by Kocks-Meching model and Avrami equation, respectively. A new constitutive equation during hot deformation was constructed to predict the flow stress considering the dynamic recrystallization. The results show that the flow stress curves predicted by the proposed equation have high correlation coefficients with the experimental data, which confirms that the developed model is accurate and effective to establish the flow stress equation of ZK60 magnesium alloy during hot deformation. Microstructure observation shows that dynamic recovery occurs in the initial stage of hot deformation. However, the microstructure turns to recrvstallization structure as the strain increases. 展开更多
关键词 magnesium alloys flow stress strain hardening dynamic recrystallization hot deformation
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Variation of Sugar, Acid and Vitamin C Contents in Fruit Development in Different Types of Kiwifruit 被引量:5
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作者 葛翠莲 刘科鹏 +2 位作者 曲雪艳 徐小彪 黄春辉 《Agricultural Science & Technology》 CAS 2013年第12期1772-1774,1778,共4页
The variation of sugar, acid and vitamin C contents in fruits of red flesh kiwifruit (Actinidia chinensis) "Hongyang" and green fresh kiwifruit (A. deliciosa) 'Jinkui' were investigated during fruit developmen... The variation of sugar, acid and vitamin C contents in fruits of red flesh kiwifruit (Actinidia chinensis) "Hongyang" and green fresh kiwifruit (A. deliciosa) 'Jinkui' were investigated during fruit development. The results showed that the to- tal sugar soluble contents of "Hongyang' and 'Jinkui" during fruit development ex- isted different variations. With the upward trend of 'Hongyang' fruit development, 95 days after full bloom (DAFB), the total soluble sugar accumulation was relatively slow, and then rose rapidly until harvest with the maximum content (6.87%). While 'Jinkui' fruit showed a fluctuant process, rising in 50 DAFB, then declining, then rising rapidly and decreasing slightly right before harvest. The variation of fruit titrat- able acid between them was more consistent, which was increased and then de- creased. The only difference was that the titratable acid content of 'Jinkui' fruit de- creased slowly from the late of fruit development to fruit ripening, similar to the maximum value, but that of 'Hongyang' fruit decreased rapidly in the late. Titrat- able acid contents of them in the maturity were 1.08% and 1.20%, respectively. The trends of sugar acid ratio for 'Hongyang' and 'Jinkui' fruit were quite different. 'Hongyang' fruit increased slowly and then rapidly; 'Jinkui' changed from decreas- ing to increasing, followed by slight decreasing in mature stage. In addition, the two kiwifruit varieties had a similar change trend of Vc content during fruit development, which changed from rapid increasing to declining, followed by slight growing in the harvest. The changing tendency of 'Jinkui' fruit was later than that of 'Hengyang'. 展开更多
关键词 KIWIFRUIT Fruit development SUGAR ACID VC VARIATION
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Deformation behavior of Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy with two initial microstructures during hot working 被引量:4
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作者 罗皎 李莲 李淼泉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期414-422,共9页
The effects of initial microstructure on the flow stress, strain rate sensitivity (m), strain hardening exponent (n), apparent activation energy (Q) for deformation of Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy were investiga... The effects of initial microstructure on the flow stress, strain rate sensitivity (m), strain hardening exponent (n), apparent activation energy (Q) for deformation of Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy were investigated using isothermal compression tests. Results show that the alloy with Widmanst-tten alpha plates shows a higher peak stress and flow softening. Additionally, the alloy with equiaxed primary alpha exhibits an early yield drop at or above 810 ℃ and at strain rates of 0.1-5.0 s^-1. In the strain range of 0.5-0.7,m of the alloy with equiaxed primary alpha is found to be larger at 0.01 s^-1 and lower deformation temperatures. This phenomenon could be reasonably explained based on the microstructure evolution. The strain has a significant effect onn of the alloy with Widmanst-tten alpha plates, which is attributed to platelet bending/kinking and dynamic globularization ofα phase. In the strain range of 0.15-0.55,Q of the alloy with Widmanst-tten alpha plates is larger. 展开更多
关键词 titanium alloy isothermal compression flow stress microstructure evolution dynamic globularization
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Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998 被引量:35
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作者 曹明奎 陶波 +2 位作者 李克让 邵雪梅 Stephen D PRIENCE 《Acta Botanica Sinica》 CSCD 2003年第5期552-560,共9页
A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in clima... A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains. 展开更多
关键词 China net primary productivity (NPP) soil heterotrophic respiration (HR) net ecosystem productivity (NEP) climate change
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The Content Variations of Main Nutrients in Storage Root Expanding Stages of Sweet Potato and Their Mutual Relationships 被引量:3
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作者 后猛 张允刚 +5 位作者 刘亚菊 王欣 唐维 闫会 马代夫 李强 《Agricultural Science & Technology》 CAS 2015年第11期2481-2484,共4页
[Objective] The content variations of the main nutrients in storage root during expanding stages and their mutual relationships in orange-fleshed sweet pota-to (Ipomoea Batatas(L.) Lam) were studied in this paper.... [Objective] The content variations of the main nutrients in storage root during expanding stages and their mutual relationships in orange-fleshed sweet pota-to (Ipomoea Batatas(L.) Lam) were studied in this paper. [Method] The dynamics of main nutritional ingredients in orange-fleshed sweet potato-variety at 40, 70, 100 and 125 days after transplanting were investigated, and these traits included the 6- carotene content, Fe content, Zn content, starch content, protein content, glucose content, fructose content, and sucrose content. The relationships among these nutri- ents were analyzed during whole developing stage. [Result] B-carotene content in the whole growth period showed straightly increasing firstly, and then decreasing trend, which was unimodal fluctuation curve. The variation tendency of protein con- tent was gently decreasing firstly and then ascending. The dynamics of starch con- tent was similar to l^carotene content, while the fluctuation was stable. The chang- ing curve of carbohydrate was opposite to starch, showing decreasing firstly and then ascending. Fe content was decreasing all the whole developing stage, falling fast and then slowing down. Moreover, Zn content was plummeting. The sucrose content in fresh storage root had significantly negative correlation with β-carotene content, and had positive correlation with fructose content. Starch content had significantly negative correlation with fructose content, and had positive correlation with Zn content. [Conclusion] These research conclusions could guide the variety to har- vest at suitable time, so as to achieve the aim of micronutrition improvement. 展开更多
关键词 Sweet potato Nutritional quality Changing dynamic Correlation
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Arrhenius-type constitutive model and dynamic recrystallization behavior of V-5Cr-5Ti alloy during hot compression 被引量:9
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作者 李鱼飞 王震宏 +2 位作者 张林英 罗超 赖新春 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第6期1889-1900,共12页
To clarify the high temperature flow stress behavior and microstructures evolution of a V-5Cr-5Ti (mass fraction, %) alloy, the isothermal hot compression tests were conducted in the temperature range of 1423-1573 K... To clarify the high temperature flow stress behavior and microstructures evolution of a V-5Cr-5Ti (mass fraction, %) alloy, the isothermal hot compression tests were conducted in the temperature range of 1423-1573 K with strain rates of 0.01, 0.1, and 1 s-1. The results show that the measured flow stress should be revised by friction and the calculated values of friction coefficient m are in the range of 0.45-0.56. Arrhenius-type constitutive equation was developed by regression analysis. The comparison between the experimental and predicted flow stress shows that the R~ and the average absolute relative error (AARE) are 0.948 and 5.44%, respectively. The measured apparent activation energy Qa is in the range of 540-890 kJ/mol. Both dis-continuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) mechanisms are observed in the deformed alloy, but dynamic recovery (DRV) is the dominant softening mechanism up to a true strain of 1.5. 展开更多
关键词 V-5Cr-5Ti alloy constitutive model flow stress dynamic recrystallization
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Study on the Quantity Dynamic Changes of Heterobacteria and Vibrios in Larvae Industrialized Culture System 被引量:7
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作者 马妍 李健 +2 位作者 王斌 王群 刘淇 《Agricultural Science & Technology》 CAS 2008年第2期116-121,共6页
[ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibr... [ Objective ] The dynamic change of heterobacteria and vibrios in larvae industrialized culture system was studied to provide scientific reference for healthy cultivation of shrimp. [ Method ] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were monitored in larvae industrialized culture system. [ Result] The heterobacteria, vibrios and pathogenic vibrio parahaemolyticus were the most in fertilized eggs of shrimp but the least in nauplius, then their number would increase with growth. During whole rearing period, both boterobacteria in larvae, vibrios in water would increase by one order of magnitude, while both vibrios in larvae and heterobacteria in water would increase by two orders of magnitude. There were many heterobacteria and vibrios but few vibrio parahaemolyticus in living bait. The correlation coefficients between larvae and heterobacteria and vibrios in water were 0. 704 and 0. 840 in culture system respectively, while the correlation among heterobacteria, vibrios in living bait and larvae, water were weak or negative. [ Conclusion ] There was a dynamic relation between water and larvae in rearing period, and restrictly control of culture condition would restrain the occurrence of disease caused by vibrio parahaemolyticus, besides that bacteria number in bait was not obviously correlated with bacteria nubmer in culture system. 展开更多
关键词 Chinese shrimp larvae Heterotrophic bacteria VIBRIO Vibrio parahaemolyticus Dynamic change
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Hot deformation behavior and processing map of Cu-Ni-Si-P alloy 被引量:6
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作者 张毅 刘平 +3 位作者 田保红 刘勇 李瑞卿 许倩倩 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第8期2341-2347,共7页
The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation ene... The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation energy, Q, was calculated and the hot compression constitutive equation was established. The processing maps of the alloy were constructed based on the experiment data and the forging process parameters were then optimized based on the generated maps for forging process determination. The flow behavior and the microstructural mechanism of the alloy were studied. The flow stress of the Cu-Ni-Si-P alloy increases with increasing strain rate and decreasing deformation temperature, and the dynamic recrystallization temperature of alloy is around 700 ℃. The hot deformation activation energy for dynamic recrystallization is determined as 485.6 kJ/mol. The processing maps for the alloy obtained at strains of 0.3 and 0.5 were used to predict the instability regimes occurring at the strain rate more than 1 s-1 and low temperature (〈650 ℃). The optimum range for the alloy hot deformation processing in the safe domain obtained from the processing map is 750-800 ℃ at the strain rate of 0.01-0.1 s i The characteristic microstructures predicted from the processing map agree well with the results of microstructural observations. 展开更多
关键词 Cu-Ni-Si-P alloy hot compression deformation dynamic recrystallization constitutive equation processing maps
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Hot deformation behavior of high Ti 6061 Al alloy 被引量:3
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作者 陈微 官英平 王振华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期369-377,共9页
The hot deformation behavior of a high Ti 6061 aluminum alloy in the temperature range from 350 to 510 ℃ and strain rate range from 0.001 to 10 s^-1 was investigated using stress-strain curve analysis, processing map... The hot deformation behavior of a high Ti 6061 aluminum alloy in the temperature range from 350 to 510 ℃ and strain rate range from 0.001 to 10 s^-1 was investigated using stress-strain curve analysis, processing map, transmission electron microscopy and electron backscatter diffraction analysis. The results show that the peak stress decreases with increasing deformation temperatures and decreasing strain rate. The average deformation activation energy is 185 kJ/mol in the parameter range investigated. The flow stress model was constructed. The main softening mechanism is dynamic recovery. The processing map was obtained using dynamic material model, and the suggested processing window is 400-440℃ and 0.001-0.1 s^-1. 展开更多
关键词 6061 A1 alloy hot deformation dynamic recovery hot processing map DISLOCATION
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Hot deformation behavior at low-rate strain of 316LN stainless steel 被引量:1
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作者 裴海祥 侯华 +1 位作者 李大赵 闫锋 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2017年第2期168-172,共5页
The study on hot deformation behavior of 316LN stainless steel at low-rate strain is very seldom at present. By sam-pling from industrial 316LN stainless steel and carrying out a compression heat deformation test by m... The study on hot deformation behavior of 316LN stainless steel at low-rate strain is very seldom at present. By sam-pling from industrial 316LN stainless steel and carrying out a compression heat deformation test by means of a Gleeble-3800 thermal simulation testing machine at a strain rate of 3×10^-3s^-1 and a deformation temperature of 600 - 1 100℃, true stress- strain curves are obtained. By analyzing the true stress-strain curves and microscopic structure of the samples, it can be conclu-ded that 1 000℃ and slightly higher temperature are suitable for low-rate strain processing of 316LN stainless steel. 展开更多
关键词 316LN stainless steel low-rate strain dynamic recrystallization
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