The paper deals mainly with the relationship between the microtexture types and the indices of physicomechanical properties of loess. The results of study demonstrate that the study of microtextures of loess is of imp...The paper deals mainly with the relationship between the microtexture types and the indices of physicomechanical properties of loess. The results of study demonstrate that the study of microtextures of loess is of importance in the prediction and preliminary evaluation of engineering geological properties of loess in a region.展开更多
This study explores the irregularity and complexity of strong earthquake ground motions from the perspective of fractal geometry, and constructs a relation with the frequency content of the ground motions. The box-cou...This study explores the irregularity and complexity of strong earthquake ground motions from the perspective of fractal geometry, and constructs a relation with the frequency content of the ground motions. The box-counting fractal dimensions and five representative period parameters of near-fault ground motions from the Chi-Chi and Northridge earthquakes are calculated and compared. Numerical results indicate that the acceleration and velocity time histories of ground motions present the statistical fractal property, and the dominant pulses of near-fault ground motions have a significant influence on their box dimensions and periods. Further, the average box dimension of near-fault impulsive ground motions is smaller, and their irregular degree of wave forms is lower. Moreover, the box dimensions of ground motions reflect their frequency properties to a large extent, and can be regarded as an alternative indicator to represent their frequency content. Finally, the box dimension D of the acceleration histories shows a considerably negative correlation with the mean period T. Meanwhile, the box dimension of the velocity histories Dye is negatively correlated with the characteristic period T and improved characteristic period Tgi.展开更多
Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. ...Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. For components operating at high temperatures, temperature measurement is very important. In many situations, the environmental conditions are too hostile for conventional techniques to be used. Researchers over the world have been looking for new techniques for temperature measurement and one such device, called Feroplug, has been developed previously by the and coworkers. The Feroplug has been patented in USA, UK and Europe by the British Technology Group. The underlying principle of the Feroplug is based on the transformation of ferrite in some specially designed duplex stainless steels. This paper describes a new invention called Sigmaplug which is a new development of the Feroplug but using an entirely different physical principle. It was discovered that the sigma phase in Fe展开更多
In order to determine a proper compaction temperature that affects the workability and compactibility of the polymer-modified asphalt（PMA）, the effect of compaction temperature was examined on the volumetric propert...In order to determine a proper compaction temperature that affects the workability and compactibility of the polymer-modified asphalt（PMA）, the effect of compaction temperature was examined on the volumetric properties and the compaction energy indices. Change in compaction temperature shows an important influence on the maximum specific gravity of mixture（G_（mm）） by internal volume change of PMA. The change in G_（mm） mainly affects the effective volume of the aggregate（V_（Eff））. Reduction in V_（Eff） from Zero shear viscosity（ZSV） to superpave temperature allows 0.1%-0.15% of the asphalt binder to occupy highly the external voids of aggregates. The volumetric properties for all compaction specimens meet superpave criteria, but the energy efforts were the lowest at ZSV temperature. Lower energy efforts at the ZSV temperature reflect easier compaction than those at excessively high temperature. Clearly, excessive compaction temperature may not be necessary to improve the compactibility and to reduce the compaction efforts.展开更多
目的:基于外来植物药丽杯角[Hoodia gordonii(Masson) Sweet ex Decne]的研究文献,结合中医药理论探讨丽杯角的中药药性,为丽杯角引入中药奠定理论基础。方法:选取国家知识基础设施数据库(CNKI)、中国学术期刊数据库(CSPD)、中文科技期...目的:基于外来植物药丽杯角[Hoodia gordonii(Masson) Sweet ex Decne]的研究文献,结合中医药理论探讨丽杯角的中药药性,为丽杯角引入中药奠定理论基础。方法:选取国家知识基础设施数据库(CNKI)、中国学术期刊数据库(CSPD)、中文科技期刊数据库(CCD)、Web of Science、PubMed、Scopus文献数据库进行检索查阅,筛选丽杯角可信度高和结论可靠的科学研究文献。最终纳入132篇相关文献,将其分为综述研究、历史应用、化学成分、临床研究、药理作用、安全性文献共6类,结合中医药理论探讨丽杯角的中药药性。结果:通过概括、归纳以及理论研究分析丽杯角中药药性为苦,微寒;归脾、胃、肝经;具有清热泻火、化浊降脂、疏肝解郁的功效。主要用于胃火炽盛,多食易饥,形体肥胖,内热消渴,肝气郁结,胸胁胀闷。结论:赋予丽杯角中药药性对将非洲植物资源引入中药,加强物种多样化,促进中医药可持续发展有重要意义。展开更多
文摘The paper deals mainly with the relationship between the microtexture types and the indices of physicomechanical properties of loess. The results of study demonstrate that the study of microtextures of loess is of importance in the prediction and preliminary evaluation of engineering geological properties of loess in a region.
基金National Natural Science Foundation of China under Grant Nos.50978047 and 11332004National Basic Research Program of China under Grant No.2010CB832703
文摘This study explores the irregularity and complexity of strong earthquake ground motions from the perspective of fractal geometry, and constructs a relation with the frequency content of the ground motions. The box-counting fractal dimensions and five representative period parameters of near-fault ground motions from the Chi-Chi and Northridge earthquakes are calculated and compared. Numerical results indicate that the acceleration and velocity time histories of ground motions present the statistical fractal property, and the dominant pulses of near-fault ground motions have a significant influence on their box dimensions and periods. Further, the average box dimension of near-fault impulsive ground motions is smaller, and their irregular degree of wave forms is lower. Moreover, the box dimensions of ground motions reflect their frequency properties to a large extent, and can be regarded as an alternative indicator to represent their frequency content. Finally, the box dimension D of the acceleration histories shows a considerably negative correlation with the mean period T. Meanwhile, the box dimension of the velocity histories Dye is negatively correlated with the characteristic period T and improved characteristic period Tgi.
文摘Improved life assessment techniques will enable engineering components to be replaced before failure, thereby reducing the risk of industrial accidents as well as minimizing financial loss due to unscheduled outages. For components operating at high temperatures, temperature measurement is very important. In many situations, the environmental conditions are too hostile for conventional techniques to be used. Researchers over the world have been looking for new techniques for temperature measurement and one such device, called Feroplug, has been developed previously by the and coworkers. The Feroplug has been patented in USA, UK and Europe by the British Technology Group. The underlying principle of the Feroplug is based on the transformation of ferrite in some specially designed duplex stainless steels. This paper describes a new invention called Sigmaplug which is a new development of the Feroplug but using an entirely different physical principle. It was discovered that the sigma phase in Fe
文摘In order to determine a proper compaction temperature that affects the workability and compactibility of the polymer-modified asphalt（PMA）, the effect of compaction temperature was examined on the volumetric properties and the compaction energy indices. Change in compaction temperature shows an important influence on the maximum specific gravity of mixture（G_（mm）） by internal volume change of PMA. The change in G_（mm） mainly affects the effective volume of the aggregate（V_（Eff））. Reduction in V_（Eff） from Zero shear viscosity（ZSV） to superpave temperature allows 0.1%-0.15% of the asphalt binder to occupy highly the external voids of aggregates. The volumetric properties for all compaction specimens meet superpave criteria, but the energy efforts were the lowest at ZSV temperature. Lower energy efforts at the ZSV temperature reflect easier compaction than those at excessively high temperature. Clearly, excessive compaction temperature may not be necessary to improve the compactibility and to reduce the compaction efforts.
文摘目的:基于外来植物药丽杯角[Hoodia gordonii(Masson) Sweet ex Decne]的研究文献,结合中医药理论探讨丽杯角的中药药性,为丽杯角引入中药奠定理论基础。方法:选取国家知识基础设施数据库(CNKI)、中国学术期刊数据库(CSPD)、中文科技期刊数据库(CCD)、Web of Science、PubMed、Scopus文献数据库进行检索查阅,筛选丽杯角可信度高和结论可靠的科学研究文献。最终纳入132篇相关文献,将其分为综述研究、历史应用、化学成分、临床研究、药理作用、安全性文献共6类,结合中医药理论探讨丽杯角的中药药性。结果:通过概括、归纳以及理论研究分析丽杯角中药药性为苦,微寒;归脾、胃、肝经;具有清热泻火、化浊降脂、疏肝解郁的功效。主要用于胃火炽盛,多食易饥,形体肥胖,内热消渴,肝气郁结,胸胁胀闷。结论:赋予丽杯角中药药性对将非洲植物资源引入中药,加强物种多样化,促进中医药可持续发展有重要意义。
