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天然胶原的稳态流变性能和数学模拟 被引量:4
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作者 段炼 薛宇 李国英 《功能材料》 EI CAS CSCD 北大核心 2010年第12期2068-2071,共4页
用旋转流变仪研究胶原溶液的稳态流变性能,讨论了浓度和温度的变化对胶原溶液流动曲线的影响。实验数据显示胶原溶液的剪切粘度随着剪切速率的增大而降低,表明胶原溶液具有明显的假塑性。同一剪切速率下,温度升高,胶原溶液的剪切粘度降... 用旋转流变仪研究胶原溶液的稳态流变性能,讨论了浓度和温度的变化对胶原溶液流动曲线的影响。实验数据显示胶原溶液的剪切粘度随着剪切速率的增大而降低,表明胶原溶液具有明显的假塑性。同一剪切速率下,温度升高,胶原溶液的剪切粘度降低;浓度增大,剪切粘度增大。用幂律方程、Carreau方程和Cross方程对胶原溶液的流动曲线进行数学拟合,结果表明幂律方程,Carreau方程和Cross方程都能准确地描述胶原的流动曲线,其中幂律方程的粘度指数K和非牛顿指数n的变化能准确反映胶原假塑性的变化;Carreau方程和Cross方程的参数比幂律方程多,其拟合得到的曲线和实验数据吻合得更好。但在本实验条件下,Carreau方程和Cross方程预测的零剪切粘度η0和无穷剪切粘度η∞不准确。 展开更多
关键词 胶原 流变性 幂律方程 Carreau方程 Cross方程
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半固态ZA12合金的瞬态流变性能 被引量:6
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作者 朱鸣芳 高志强 苏华钦 《金属学报》 SCIE EI CAS CSCD 北大核心 1999年第10期1021-1023,共3页
采用自行研制的高温同轴双简流变仪对半固态ZA12合金的流变性能进行研究,结果表明,半固态合金的剪切应力与剪切时间的关系曲线的特征与固相分数和剪切速率有关。此外,在稳态条件和瞬态条件下。
关键词 半固合金 流变性 固相分数 铝合金
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纤维素/氯化锂/N,N-二甲基乙酰胺溶液的流变性能 被引量:3
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作者 余美琼 袁红梅 陈礼辉 《纺织学报》 EI CAS CSCD 北大核心 2021年第5期23-30,共8页
为探究纤维素溶液流变性能对其静电纺丝可纺性的影响,研究了纤维素/氯化锂(LiCl)/N,N-二甲基乙酰胺(DMAc)溶液的稳态流变性能和动态流变性能,并在此基础上进行静电纺丝。结果表明:纤维素/LiCl/DMAc溶液为假塑性流体,溶液的表观黏度、稠... 为探究纤维素溶液流变性能对其静电纺丝可纺性的影响,研究了纤维素/氯化锂(LiCl)/N,N-二甲基乙酰胺(DMAc)溶液的稳态流变性能和动态流变性能,并在此基础上进行静电纺丝。结果表明:纤维素/LiCl/DMAc溶液为假塑性流体,溶液的表观黏度、稠度系数、结构黏度指数均随着温度的升高而减小,随着纤维素质量分数的增加而增大,而非牛顿指数的变化规律则相反;20~60℃温度下,质量分数为2.5%和3.0%的纤维素/LiCl/DMAc溶液的非牛顿指数更接近1,具有较稳定的流变性能,且结构黏度指数较小,更易进行纺丝操作;室温下,质量分数为3.0%的纤维素/LiCl/DMAc溶液更适宜进行静电纺丝。 展开更多
关键词 纤维素 氯化锂/N N-二甲基乙酰胺 流变性 流变性 静电纺丝 可纺性
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海南苗族女性服饰的“短缺”设计特色及变迁分析
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作者 张红梅 《创意设计源》 2024年第2期63-67,共5页
海南苗族女性的传统服饰是我国苗族女性服饰中的一种独立类型,但外界对其服饰的设计特色知之甚少。由研究可知,海南苗族女性的传统服饰具有突出的“短缺”设计特征,主要表现在上衣的前襟左长右短、蜡染裙的门襟开敞暴露等方面,但又通过... 海南苗族女性的传统服饰是我国苗族女性服饰中的一种独立类型,但外界对其服饰的设计特色知之甚少。由研究可知,海南苗族女性的传统服饰具有突出的“短缺”设计特征,主要表现在上衣的前襟左长右短、蜡染裙的门襟开敞暴露等方面,但又通过上衣和下裙相互取长补短的配套设计弥补了这种“短缺”。海南苗族女性服饰具有半遮半露的独特风格,是适应海南苗族独特的地理居住环境和社会历史发展条件下的产物。同时,针对因这种“短缺”设计而引起的当代海南苗族女性传统服装样式的变迁现象,从非遗传承活态流变性规律的角度进行了分析和思考。 展开更多
关键词 海南苗族 女性服饰 少数民族服饰 流变性
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非物质文化遗产传承学校活态保护制度研究 被引量:7
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作者 齐爱民 曾钰诚 《创新》 2017年第1期99-108,共10页
非物质文化遗产内部特性所具有的活态流变性和传承性是构建传承学校活态保护制度的先决条件,同时出于对非物质文化遗产的保护以及自身不断传承、发展的现实需要,又使其与传承学校必然地结合在一起。非物质文化遗产传承学校活态保护制度... 非物质文化遗产内部特性所具有的活态流变性和传承性是构建传承学校活态保护制度的先决条件,同时出于对非物质文化遗产的保护以及自身不断传承、发展的现实需要,又使其与传承学校必然地结合在一起。非物质文化遗产传承学校活态保护制度正逐步成为非物质文化遗产发展、传承、保护、开发的创新性制度选择与制度模式。针对现行制度的不足,通过构建以传承学校数据信息库、教育部专项财政扶持制度、"校企共建"公益基金制度、传承人引进制度、传承人教学考核制度、传承学校评估退出制度、传承学校交流合作制度为内容的传承学校活态保护制度,以更好保护非物质文化遗产和矫正现行制度的缺陷。 展开更多
关键词 非物质文化遗产 流变性 保护 制度构建
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壳聚糖/聚乙烯醇的流变行为及其可纺性研究
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作者 曾文超 孙浩东 +2 位作者 张宗威 李建国 陈礼辉 《林产化学与工业》 CAS CSCD 北大核心 2023年第5期25-31,共7页
采用乙酸(HAc)作为溶剂,配制壳聚糖(CS)/聚乙烯醇(PVA)纺丝液,探究纺丝液稳态流变和动态流变性能并考察其静电纺丝的可行性。研究结果表明:随着CS质量分数的增加,纺丝液的稠度系数、结构黏度指数、表观黏度、储能模量(G′)、损耗模量(G... 采用乙酸(HAc)作为溶剂,配制壳聚糖(CS)/聚乙烯醇(PVA)纺丝液,探究纺丝液稳态流变和动态流变性能并考察其静电纺丝的可行性。研究结果表明:随着CS质量分数的增加,纺丝液的稠度系数、结构黏度指数、表观黏度、储能模量(G′)、损耗模量(G″)和复合黏度(η*)均相应增加,非牛顿指数相应减小,不利于CS/PVA纺丝液静电纺丝。随着测试温度的增加,纺丝液的稠度系数、结构黏度指数、表观黏度、G′、G″和η*均相应减小,非牛顿指数相应增加,纺丝液流动性能加强,可纺性提升。当CS质量分数为3.0%时,纺丝液在测试温度30℃下的稠度系数和结构黏度指数均较小,分别为7.9781和2.16,且非牛顿指数为0.8877接近于1,表明该纺丝液具有良好的流动性和加工性。结合SEM和流变行为分析,在室温条件下CS质量分数为3.0%的CS/PVA纺丝液呈现优异的可纺性,可以构建连续、均匀且不带珠状连结的纳米纤维。 展开更多
关键词 壳聚糖 流变性 流变性 静电纺丝 纳米纤维
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砂岩蠕变力学特性及流变模型研究 被引量:2
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作者 蒋腾健 赵立财 余建星 《水电能源科学》 北大核心 2021年第3期124-128,133,共6页
水利枢纽工程中库岸高边坡流变现象显著,是工程长期稳定性的潜在隐患。以某大型水利枢纽工程近坝库岸高边坡石英砂岩为例,采用RLW-2000岩石三轴流变试验系统进行不同应力状态下的蠕变力学试验。结果表明,岩石瞬时应变、蠕应变随围压的... 水利枢纽工程中库岸高边坡流变现象显著,是工程长期稳定性的潜在隐患。以某大型水利枢纽工程近坝库岸高边坡石英砂岩为例,采用RLW-2000岩石三轴流变试验系统进行不同应力状态下的蠕变力学试验。结果表明,岩石瞬时应变、蠕应变随围压的增加而逐渐增大,初始、稳态和极限加速蠕变速率随围压的提升而递增;围压促进砂岩蠕变变形发展,高围压下的初始蠕变速率可能大于低围压下的极限加速蠕变速率;砂岩在围压5、10、15MPa下的长期强度分别为24.8、32.3、39.7MPa,长期强度随围压的增强而逐渐增大。结合试验成果,分析砂岩的流变性态为粘性-粘弹性-粘塑性,基于统一流变力学模型理论,确定H-H|N-N-N|S模型结构。由于传统元件模型难以辨识不同加速蠕变阶段曲线形态,引入SN和SP非线性元件改进传统模型,得到一个新的非线性蠕变力学模型,并将其拓展到三维情形。辨识蠕变试验数据,对比预测曲线和试验数据,证明了所建模型的可行性和合理性。研究成果可为水利枢纽工程的长期稳定性分析提供参考。 展开更多
关键词 砂岩 应变 蠕变速率 流变性态 非线性 力学模型
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Rheological properties of warm mix asphalt binder by DSR test at medium temperature 被引量:6
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作者 张久鹏 刘国强 +2 位作者 杜慧 裴建中 马学军 《Journal of Southeast University(English Edition)》 EI CAS 2015年第3期384-388,共5页
The rheological properties including the complex modulus G* and the phase angle δof matrix and warm mix asphalt (WMA)binders were measured by using the dynamic shear rheometer (DSR ) test at the medium temperatu... The rheological properties including the complex modulus G* and the phase angle δof matrix and warm mix asphalt (WMA)binders were measured by using the dynamic shear rheometer (DSR ) test at the medium temperature ranging from 16 to 40 ℃,and the relationships between the fatigue factor G* sinδand the matrix binder property,WMA additive and test temperature were established.It is found that G* decreases with the increasing temperature while δincreases inversely,and G* of the asphalt binder with high WMA additive dosage is large,and δis small.G*sinδexponentially decreases with the increasing temperature and linearly increases with the increase in additive dosage,and the amplitudes of variation are large at low temperatures and high additive dosages.The effect of WMA additive on the rheological property is more remarkable for the matrix asphalt binder with low G*.Besides,aging has a great effect on the property of matrix asphalt binder,and a slight effect on the interaction between asphalt and additive.The high additive dosage can increase the fatigue cracking potential of the asphalt binder. 展开更多
关键词 warm mix asphalt dynamic shear rheometer (DSR test medium temperature rheological property fatigue factor
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Microstructure and property of rheocasting AZ91 slurry produced via ultrasonic vibration process 被引量:1
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作者 尧军平 孙众 +3 位作者 杨涛 Bharat BBUSHAN 龙文元 张磊 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期619-625,共7页
The microstructure and mechanical properties of rheocasting AZ91 magnesium alloy were investigated. The semisolid slurry of this alloy was prepared by ultrasonic vibration (USV) process and then shaped by high press... The microstructure and mechanical properties of rheocasting AZ91 magnesium alloy were investigated. The semisolid slurry of this alloy was prepared by ultrasonic vibration (USV) process and then shaped by high pressure diecasting (HPDC). The results show that fine and spherical a-Mg particles were obtained by USV at the nucleation stage, which was mainly attributed to the cavitation and acoustic streaming induced by the USV. Extending USV treatment time increased the solid volume fraction and average particle size, the shape factors were nearly the same, about 0.7. Excellent semisolid slurry of AZ91 magnesium alloy could be obtained within 6 rain by USV near its liquidus temperature. The rheo-HPDC samples treated by USV for 6 min had the maximum ultimate tensile strength and elongation, which were 248 MPa and 7.4%, respectively. It was also found that the ductile fracture mode prevailed in the rheocasting AZ91 magnesium alloy. 展开更多
关键词 AZ91 magnesium alloy ultrasonic vibration RHEOCASTING semisolid slurry mechanical properties fracture surface
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MORPHOLOGICAL MODEL FOR RHEOLOGICAL PROPERTIES OF PLANT CELL SUSPENSION CULTURE SYSTEM
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作者 吴兆亮 元英进 +1 位作者 邢允 胡宗定 《Transactions of Tianjin University》 EI CAS 1999年第2期61-64,共4页
This paper puts forward a physical and mathematical model for the rheological properties of a plant cell suspension culture system.The model can explain why the system is pseudoplastic satisfactorily,thus the rheologi... This paper puts forward a physical and mathematical model for the rheological properties of a plant cell suspension culture system.The model can explain why the system is pseudoplastic satisfactorily,thus the rheological properties of the system as the effect of the flow behavior index on plant cell concentration are interpreted correctly and the mechanism of the rheological properties of the system is further understood.Therefore the model can be applied in the technological design and optimum conditions of the system and the reformation,evaluation and scale up of reactors. 展开更多
关键词 morphological model rheological property plant cell suspension culture pseudoplastic fluid
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Mechanical model of control of key strata in deep mining 被引量:2
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作者 Pu Hai Zhang Jian 《Mining Science and Technology》 EI CAS 2011年第2期267-272,共6页
Based on the characteristic of deep rock layers and the theory of key strata,we analysed elastic mechanical characteristics of key strata by using elastic plate theory.The results show that the deformation and distrib... Based on the characteristic of deep rock layers and the theory of key strata,we analysed elastic mechanical characteristics of key strata by using elastic plate theory.The results show that the deformation and distribution of internal forces of key strata vary with different mine boundary conditions.The boundary values of key strata with three point boundaries and one fixed boundary is greater than that with four fixed boundaries.Considering the rheology of key strata under low stress conditions,we selected a generalized Kelvin model to analyse the rheology characteristics of the key strata and discovered their instantaneous elastic phases.The rate of deformation decreased over time to the point where the key strata reached stability.But over this time,the effect on deformation became very clear. For high stress conditions,we chose a Burgers model and found deformation of key strata in the form of attenuation and steady-state creep and although the rate of deformation remained constant,secondary creep was obvious,causing instability in the system.As well,we analysed the effect of creep buckling and derived a relation between buckling force and time. 展开更多
关键词 Deep mining Key strata RHEOLOGY Creep buckling
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Viscoelastic Characteristics of Asphalt Binders at Softening Point Temperature 被引量:1
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作者 Fan Liang Lin Jian +2 位作者 Wei Jianming Zhang Yuzhen Wang Lin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2014年第3期19-25,共7页
In this paper, in order to investigate the viscoelasticity of asphalt binder at the softening point temperature, more than 30 different asphalt binders were selected and tested by dynamic rheological scan method using... In this paper, in order to investigate the viscoelasticity of asphalt binder at the softening point temperature, more than 30 different asphalt binders were selected and tested by dynamic rheological scan method using a dynamic shear rheometer(DSR). The softening points and the rheological parameters of the asphalt samples were measured and analyzed. The results indicated that at the softening point temperature the neat asphalt and the SBS modified asphalt showed two different rheological states. The neat asphalt binders had a majority of viscous components in viscoelastic composition, with the phase angles being mostly higher than 80 o. The SBS modified binders had lower phase angles, with their elasticity still retained. Meanwhile, the Shapiro-Wilk normality test showed that at a confidence level of 0.05, at whatever aging state, the neat asphalt had a stable complex modulus corresponding to the softening point, which was 13.034 kPa at a standard deviation of 2.105 kPa under the same test condition. The softening point of neat asphalt binder can be calculated via the equivalent modulus rule. It is found out that there is a good relationship between the calculated and the measured softening points. And it is suggested that more data are needed to validate this finding. 展开更多
关键词 asphalt binder softening point VISCOELASTICITY equivalent modulus temperature
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Analysis and Verification on the Chain-like Model with Normal Distribution of Magnetorheological Elastomer 被引量:1
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作者 Miao Yu Yong-qiang Xia Xiao-rui Yan 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第5期545-550,I0002,共7页
Magnetorheological elastomer (MRE) is a new kind of smart materials, the rheological properties can be controlled rapidly by the external magnetic field. It is mainly composed of rubber and micron-sized ferromagneti... Magnetorheological elastomer (MRE) is a new kind of smart materials, the rheological properties can be controlled rapidly by the external magnetic field. It is mainly composed of rubber and micron-sized ferromagnetic particles, which forms a chain-like structure. Therefore its mechanical, electric, and magnetic properties can be changed by the applied magnetic field, which is called as the magneto-induced effect. But this effect is not remarkable enough currently for the engineering application. So it is important for material preparation to optimize parameters to enhance the magneto-induced effect. In this work, based on chain-like model, some factors influencing the magneto-induced effect of MRE were analyzed theoretically by using dipole method with the normal distribution of chain's angle introduced. The factors included the oblique angle of particles chains, magnetic field intensity, and shear strain, etc. Some experiments were also carried out. 展开更多
关键词 Magnetorheological elastomer DIPOLE Magneto-induced effect Normal distri-bution
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Effect of Ultraviolet Aging on Asphalt Rheological Properties
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作者 Wang Jiani Xue Zhongjun +1 位作者 Tan Yiqiu Zhang Lei 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第4期26-32,共7页
This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis (DMA) method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienc... This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis (DMA) method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienced ultravio- let aging, the low temperature performance of asphalt binder decreased significantly, with its complex modulus increased and phase angle decreased along with changing rheological properties as compared to the performance of original asphalt binder. The ultraviolet aging process would make asphalt binder more sensitive to brittle and fatigue failure. On the basis of the time-temperature superposition principle (TTSP), the viscoelastic transition frequency (coT) is proposed to evaluate the effect of ultraviolet aging. It is found that with the increase in ultraviolet aging time, the cox moves to the lower frequency range gradually. Since the viscoelastic transition frequency is sensitive to the effect of aging, it can be used as an indicator of ultraviolet aging. 展开更多
关键词 ASPHALT ultraviolet aging rheological properties viscoelastic transition frequency
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Spatio-temporal variability of periphytic protozoa related to environment in the Niyang River,Tibet,China 被引量:1
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作者 刘海平 叶少文 +6 位作者 杨学峰 郭传波 张惠娟 范丽卿 张良松 Sovan Lek 李钟杰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第3期489-500,共12页
The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau fiver ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and fiver ecolo... The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau fiver ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and fiver ecology. In this study, the composition, abundance, and diversity of periphytic protozoa were investigated across four seasons from 2008 to 2009 to better understand their spatio-temporal patterns and relationship to the environment. Our investigation shows that periphytic protozoa in the Niyang River contained 15 genera, belonged to Tubulinea, Alveolata, Discosea and Rhizaria, Alveolata possessed most genera, up to nine, with highest share in abundance, exceeding 50%, Difflugia and Glaucoma were dominant genera. Moreover, four diversity indices of periphytic protozoa, including species richness, total abundance, Shannon-Wiener diversity index and Pielou's evenness index, displayed a significant descending trend as the seasons continued, in the order of winter, spring, summer and autumn; with a significant difference existing between winter and summer (or autumn) for Shannon-Wiener diversity index and species richness (P〈0.05). Four of these diversity indices also presented a V-shaped pattern between the upper middle course of the Niyang River and the confluence of the Niyang River and Yarlung Zangbo River, with the lowest value occurred in the middle course of the Niyang River. However, no significant variation was found through the Niyang River (P〉0.05). In addition, canonical correlation analysis (CCA) shows that the densities of Difflugia, Glaucomais, Enchelydium, Cyphoderia, and Enchelys correlate with water temperature, alkalinity, hardness, pH, and dissolved oxygen, respectively. Lastly, the relationship between periphytic protozoa diversity and the environmental factors of the Niyang River can be predicted using classification and regression trees (CART) annalysis, which suggests that the total abundance and Shannon-Wiener diversity index would be higher when the elevation is above 3 308 m. On the other hand, the Shannon-Wiener diversity index and Pielou's evenness index would be lower when pH and ammoniacal nitrogen have lower or higher values. Finally yet importantly, close attention should be paid to periphytic protozoa and its environment to ensure sustainable development of the Niyang River ecosystem. 展开更多
关键词 Tibetan Plateau Niyang River periphytic protozoa ENVIRONMENT spatio-temporal dynamic
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Low-temperature Properties of Biodiesel:Rheological Behavior and Crystallization Morphology 被引量:1
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作者 Chen Boshui Sun Yuqiu +2 位作者 Fang Jianhua Wang Jiu Wu Jiang (Department of Petrochemistry,Logistical Engineering University,Chongqing 401311,China) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第1期29-33,共5页
A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperatu... A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals. 展开更多
关键词 BIODIESEL cold flow property VISCOSITY RHEOLOGY CRYSTALLIZATION
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Laboratory and Field Investigations of Polymer and Crumb Rubber Modified Bitumen 被引量:9
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作者 Jan B. Krol Piotr Radziszewski +2 位作者 Karol J. Kowalski Michal Samowski Pawel Czajkowski 《Journal of Civil Engineering and Architecture》 2014年第10期1327-1334,共8页
In this paper, properties of new kind of modified bitumen are presented. Bituminous binder was modified with mix modification using polymer and additive of crumb rubber. Terminal blend process at the refinery was appl... In this paper, properties of new kind of modified bitumen are presented. Bituminous binder was modified with mix modification using polymer and additive of crumb rubber. Terminal blend process at the refinery was applied to produce the mixed modified binder. Laboratory tests were focused on the characterization of the properties of 45/80-55 CR binder with comparison to reference 50/70 and conventional polymer modified 45/80-55 bitumen. Based on conventional binder tests such as penetration, softening point and Fraass breaking point as well as BBR (bending beam rheometer) and DSR (dynamic shear rheometer) tests, rheological properties were investigated. For determination of stability of the polymer and crumb rubber, modified bitumen tube testing method was used. Based on the results analysis, improvement of the viscoelastic properties of polymer and crumb rubber modified bitumen was observed. Conventional properties and stability tests showed that it is possible to pass standard requirements for polymer modified bitumen. Mixed modification and terminal blend allow to use crumb rubber as a modifier with elimination of the separation of crumb rubber during transportation and storage at high temperature. In this paper, experience from filed sections with use of the asphalt mixture with new kind of modified bitumen is presented. 展开更多
关键词 Polymer modified bitumen crumb rubber terminal blend.
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Effects of Moisture on Rheological Properties of PAV Aged Asphalt Binders
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作者 Yu Xin Wei Jianming +3 位作者 Liu Yunxin Luo Yilin Wang Ying Yin Long 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第3期38-44,共7页
For the most coastal areas where the air is very humid,study on the effect of humidity on the performance of asphalt has its practical significance.However,limited research has been done to investigate the effect of h... For the most coastal areas where the air is very humid,study on the effect of humidity on the performance of asphalt has its practical significance.However,limited research has been done to investigate the effect of humidity on rheological properties of asphalt.In this study,asphalt binders were aged in the pressure aging vessel(PAV)under different conditions of moisture and aging time.Then Dynamic Shear Rheometer(DSR)and Bending Beam Rheometer(BBR)measurements were conducted to obtain the parameters relating to the complex modulus,phase angle,failure temperature,and creep stiffness.It was found that the low temperature performance decreased as evidenced by the results of the creep stiffness.While there were no significant differences among conditioned binders based on complex modulus G*and phase angleδ,it was found that theδvalue increased when the humidity increased from 0% to 80% ,and then theδvalue decreased when the humidity increased to 100% .In addition,the results of the failure temperature indicated that the humidity of 80% would be a critical point for the high temperature performance of the asphalt binders. 展开更多
关键词 humidity PAV aging asphalt binders rheological properties
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Metal-ligand coordinated Ca(DS)_2/C_(14)DMAO/H_2O system:Phase behavior and rheological property
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作者 LI Xiang TIAN HongShan +1 位作者 DING Qi SONG AiXin 《Science China Chemistry》 SCIE EI CAS 2011年第3期490-496,共7页
A metal-ligand coordinated surfactant system formed by calcium dodecylsulfate(Ca(DS)2)/tetradecyldimethylamine oxide (C14DMAO)/H2O was studied in terms of surface tension,conductivity,negative-staining TEM,phase behav... A metal-ligand coordinated surfactant system formed by calcium dodecylsulfate(Ca(DS)2)/tetradecyldimethylamine oxide (C14DMAO)/H2O was studied in terms of surface tension,conductivity,negative-staining TEM,phase behavior and rheological operation.In C14DMAO solution,when Ca(DS)2 is added,metal-ligand complexes form between the Ca 2+and N→O group of C14DMAO.Under this metal-ligand driving force,different phases can be obtained at different concentrations and different ratios of Ca(DS)2 and C14DMAO.At the fixed C14DMAO concentration,L1-phase consisting of spherical micelles forms at first.With the addition of Ca(DS)2,the spherical micelles elongate to be wormlike micelles and then after an L1/L-two phase region,the birefringent vesicle-phase(Lv-phase)region is observed.When Ca(DS)2 concentration continues to increase,a gel-phase region is found after the Lv-phase region and then precipitates of undissolved Ca(DS)2 appear.The transition between different phases is affected by temperature remarkably.The wormlike micellar solutions and vesicle solutions were checked by rheological measurements and showed apparent viscoelasticity at high surfactant concentrations. 展开更多
关键词 metal-ligand phase behavior Lvphase wormlike micellar phase rheological property
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Excellent ductility and serration feature of metastable CoCrFeNi high-entropy alloy at extremely low temperatures 被引量:18
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作者 Junpeng Liu Xiaoxiang Guo +10 位作者 Qingyun Lin Zhanbing He Xianghai An Laifeng Li Peter K. Liaw Xiaozhou Liao Liping Yu Junpin Lin Lu Xie Jingli Ren Yong Zhang 《Science China Materials》 SCIE EI CSCD 2019年第6期853-863,共11页
Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA... Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature. 展开更多
关键词 high-entropy alloy liquid-helium temperature TWINNING phase transition serration feature
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