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Effect of carbon black on the dynamic moduli of asphalt mixtures and its master curves

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 918-925页

作者： Chuangmin li Fanbo NING yuanyuan li Engineering Laboratory of Spatial Information Technology of Highway Geological Disaster Early Warning in Hunan Province Changsha University of Science & Technology Changsha 410114 China School of Traffic and Transportation Engineering Changsha University of Science &Technology Changsha 410114 China State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology Wuhan 430070 China

Modulus is one of the main parameters during the design of asphalt pavement structure, the newest specifications of China gives the dynamic moduli ranges of commonly used asphalt mixtures with base asphalt (BA) or styrene-butadiene-styrene modified asphalt (SBS MA), while the moduli ranges of mixtures with carbon black modified asphalt (CB MA) are not recommended. To investigate the CB effect on the dynamic moduli of CB MA mixtures, one commonly used asphalt mixture (AC-20) was designed with BA, SBS MA, and CB MA, respectively. Then, the uniaxial compression dynamic modulus tests were conducted at different temperatures and loading frequencies, the master curves of asphalt mixtures were analyzed based on the time-temperature equivalence principle. The results show that with increasing loading frequency, the temperature dependence of dynamic moduli of all asphalt mixtures tend to be less obvious. Both SBS and CB can decrease the temperature sensitivity of asphalt mixture, the SBS MA mixture has the lowest temperature sensitivity, followed by CB MA and BA mixture. In addition, CB and SBS can obviously improve the dynamic modulus of the BA mixture, enhance the anti-deformation performance of pavement structure, and the improvement effect of CB is almost the same with SBS.

关键词： dynamic modulus carbon black master curve modified asphalt asphalt mixture

Explicit Analytical Solutions of Radial Permeable Power Rate Flow

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 220-223页

作者： li yuanyuan CAI Ruixian Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China

The research of different kinds of permeable non-Newtonian fluid flow is increasing day by day owing to the development of science,technology and production *** is most common to use power rate equation to describe such ***,this equation is nonlinear and very difficult to derive explicit exact analytical ***,people can only derive approximate solutions with numerical ***,an advanced separating variables method which can derive exact analytical solutions easier is developed by Academician CAI Ruixian（the method of separating variables with addition）.It is assumed that the unknown variable may be indicated as the sum of one-dimensional functions rather than the product in the common method of separating *** method is used to solve the radial permeable power rate flow unsteady nonlinear equations on account of making the process *** concise（no special functions and infinite series） exact analytical solutions is derived with the new method about this flow to develop the theory of non-Newtonian permeable fluid,which are exponential solution,two-dimensional function with time and radius,logarithmic solution,and double logarithmic solution,*** addition,the method of separating variables with addition is developed and applied instead of the conventional multiplication *** is proven to be promising and encouraging by the *** solutions yielded will be valuable to the theory of the permeable power rate flow and can be used as standard solutions to check numerical methods and their differencing schemes,grid generation ways,*** also can be used to verify the accuracy,convergency and stability of the numerical solutions and to develop the numerical computational approaches.

关键词： non-Newtonian fluid analytical solution permeable power rate flow method of separating variables with addition

Developing a novel quantitative parameter for characterizing spatial distribution of fish following exposure to chemicals and wastewater:Behavioral Gini coefficient

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Journal of Environmental Sciences 2024年第7期141卷 129-138页

作者： Xuanyue Chen yuanyuan li Zhanfen Qin State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

While the spatial distribution pattern of fish is increasingly used for toxicological test o chemicals or wastewater,no ideal parameter is available for quantitative assessment of spa tial distribution,especially uneven distribution with multiple ***,to develop a quantitative assessment parameter for spatial distribution,the zebrafish were exposed to ethanol,pentylenetetrazole(PTZ),paraquat dichloride(paraquat)and wastewater,followed by a behavioral test in a narrow *** data was acquired and analyzed by id Tracker and *** comparing the effects of all treatments on behavior parameters we confirmed that the spatial distribution was more easily altered rather than general loco motor parameters,e.g.0.7-70 mg/L PTZ and 5-20 mg/L paraquat being effective for altering spatial distribution but having little effects on general locomotor *** on the heatmap,i.e.,the cumulative proportion of grids and that of frequency in grids,we calcu lated the behavioral Gini coefficient(G_(b))for quantitative assessment of fish spatial distri *** Gini coefficient ranged from zero to 1,with larger values meaning poorer even ness of spatial *** note,G_(b)showed smaller coefficient of variations(CV)with3%-19%between replicate tanks in all treatments than the highest frequency(4%-79%),dis playing well ***,G_(b)addressed the challenge of the complicated heatmap with multiple ***,the behavioral Gini coefficient we established is an idea parameter to quantitatively assess spatial distribution of fish shoal,which is expected to be applied in toxicity testing for chemicals and wastewater and automatic quality monitoring for surface water and aquaculture water.

关键词： Zebrafish Behavioral test Spatial distribution Behavioral Gini coefficient

Unsteady 3D algebraically explicit analytical solutions for bio-heat transfer equations

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Science China(Technological Sciences) 2011年第2期54卷 362-368页

作者： li yuanyuan CAI RuiXian Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

Reasonable unsteady three-dimensional explicit analytical solutions are derived with different methods for the widely used bio-heat transfer equation–Pennes *** condition to decide temperature oscillation is obtained in this *** other cases the temperature would vary monotonously along geometric coordinates as time goes *** have been very few open reports of explicit unsteady multidimensional exact analytical solutions published in *** its irreplaceable theoretical value,the analytical solution can also serve as standard solution to check numerical calculation,and therefore promote the development of numerical method of computational heat *** addition,some new special methods have been given originally and deserved further attention.

关键词： Pennes equation temperature oscillation three-dimensional unsteady analytical solutions

Morphological Tracing and Functional Identification of Monosynaptic Connections in the Brain:A Comprehensive Guide

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Neuroscience Bulletin 2024年第9期40卷 1364-1378页

作者： yuanyuan li yuanyuan Fang Kaiyuan li Hongbin Yang Shumin Duan li Sun Affiliated Mental Health Center and Hangzhou Seventh People’s Hospital and School of Brain Science and Brain Medicine Zhejiang University School of MedicineHangzhou310058China liangzhu Laboratory MOE Frontier Science Center for Brain Science and Brain-machine IntegrationState Key Laboratory of Brain-machine IntelligenceZhejiang UniversityHangzhou311121China NHC and CAMS Key Laboratory of Medical Neurobiology Zhejiang UniversityHangzhou310058China Department of Neurobiology and Department of Neurology of the Second Affiliated Hospital Zhejiang University School of MedicineHangzhou310058China Institute of Basic Medical Sciences Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing100005China

Behavioral studies play a crucial role in unraveling the mechanisms underlying brain *** advances in optogenetics,neuronal typing and labeling,and circuit tracing have facilitated the dissection of the neural circuitry involved in various important *** identification of monosynaptic connections,both upstream and downstream of specific neurons,serves as the foundation for understanding complex neural circuits and studying behavioral ***,the practical implementation and mechanistic understanding of monosynaptic connection tracing techniques and functional identification remain challenging,particularly for inexperienced *** application of these methods and misinterpretation of results can impede experimental progress and lead to erroneous *** this paper,we present a comprehensive description of the principles,specific operational details,and key steps involved in tracing anterograde and retrograde monosynaptic *** outline the process of functionally identifying monosynaptic connections through the integration of optogenetics and electrophysiological techniques,providing practical guidance for researchers.

关键词： Trans-monosynaptic Retrograde Anterograde Viral tool Neural circuit Optogenetics Electrophysiology

A Review on the Coupled Method of Using the Magnetic and Acoustic Fields for Biological Tissue Imaging

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Chinese Journal of Electrical Engineering 2023年第1期9卷 47-60页

作者： yuanyuan li Guoqiang liu Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China Institute of Electrical Engineering and Advanced Electromagnetic Drive Technology Qilu ZhongkeJinan 250102China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China

Magnetic field and acoustic field coupled imaging methods mainly include magnetoacoustic tomography,magneto-acousto-electrical tomography,and thermoacoustic tomography,all of which non-invasively achieve the electrical conductivity imaging of tissues with a resolution of up to the millimeter *** principles of these three imaging methods and the research progress in the last two decades are ***,the principles of the three magnetic and acoustic field coupled methods are individually *** progress in medical electromagnetic imaging is further elaborated,and finally the future directions and summary of the coupled imaging methods are summarized.

关键词： Biomedical imaging electromagnetic field acoustic field electrical conductivity coupled method

A simple strategy for constructing acylhydrazone photochromic system with visible color/emission change and its application in photo-patterning

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Chinese Chemical Letters 2020年第12期31卷 3271-3275页

作者： yuanyuan liu Qiuchen Peng yuanyuan li Hongwei Hou Kai li Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China School of Chemistry and Chemical Engineering Henan University of TechmologyZhengzhou 450001China

As a potential photochromic system,acylhydrazones exhibit many outstanding adva ntages including low cost,simple synthesis and high modifiability compared with some classic photochromic ***,the absorption wavelengths of acylhydrazones usually locate in ultraviolet regio n,which makes the band separation between the absorbance maxima of its irradiated and unirradiated forms cannot be observed by naked eyes and greatly limits their practical *** this work,a simple strategy for constructing acylhydrazone photochromic system with visible color/emission change is *** 6 G hydrazine-2-aldehyde-pyridine Schiff base(compound 3)is designed and synthesized by combining acylhydrazone with Rhodamine 6 G *** introduction of Rhodamine 6 G moiety to 3 not only makes it remain all the advantages of acylhydrazone photochromic system but also exhibits visible photo-induced color/emission changes both in solution and in a solid ***,3 exhibits reversible photochromic property with good fatigue re sistance,which makes it an excellent candidate for p hoto-patterning.

关键词： Photochromism Acylhydrazone Rhodamine6G E/Z isomerization Photo-patternin

Experimental and numerical study on surface roughness of magnetorheological elastomer for controllable friction

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Friction 2020年第5期8卷 917-929页

作者： Rui li Xi li yuanyuan li Ping-an YANG Jiushan liU Key Laboratory of Industrial Internet of Things&Networked Control Ministry of EducationChongqing University of Posts and TelecommunicationsChongqing 400065China School of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065China

Magnetorheological elastomer (MRE) is a type of smart material of which mechanical and electrical properties can be reversibly controlled by the magnetic field. In this study, the influence of the magnetic field on the surface roughness of MRE was studied by the microscopic modeling method, and the influence of controllable characteristics of the MRE surface on its friction properties was analyzed by the macroscopic experimental method. First, on the basis of existing studies, an improved mesoscopic model based on magneto-mechanical coupling analysis was proposed. The initial surface morphology of MRE was characterized by the W–M fractal function, and the change process of the surface microstructures of MRE, induced by the magnetic interaction between particles, was studied. Then, after analyzing the simulation results, it is found that with the increase in the magnetic field and decrease in the modulus of rubber matrix, the surface of MRE changes more significantly, and the best particle volume fraction is within 7.5%–9%. Furthermore, through experimental observation, it is found that the height of the convex peak on the surface of MRE decreases significantly with the action of the magnetic field, resulting in a reduction in the surface roughness. Consistent with the simulation results, a particle volume fraction of 10% corresponds to a maximum change of 14%. Finally, the macroscopic friction experiment results show that the friction coefficients of MREs with different particle volume fractions all decrease with the decrease in surface roughness under the magnetic field. When the particle volume fraction is 10%, the friction coefficient can decrease by 24.7% under a magnetic field of 400 mT, which is consistent with the trend of surface roughness changes. This shows that the change in surface morphology with the effect of the magnetic field is an important factor in the control of MRE friction properties by magnetic field.

关键词： controllable friction surface roughness magnetorheological elastomer(MRE) mesoscopic model coupled magneto-mechanical analysis numerical simulation

Improving water-use efficiency by decreasing stomatal conductance and transpiration rate to maintain higher ear photosynthetic rate in drought-resistant wheat

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The Crop Journal 2017年第3期5卷 231-239页

作者： Yuping li Hongbing li yuanyuan li Suiqi Zhang State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources

In wheat, the ear is one of the main photosynthetic contributors to grain filling under drought stress conditions. In order to determine the relationship between stomatal characteristics and plant drought resistance, photosynthetic and stomatal characteristics and water use efficiency(WUE) were studied in two wheat cultivars: the drought-resistant cultivar ‘Changhan 58' and the drought-sensitive cultivar ‘Xinong 9871'. Plants of both cultivars were grown in pot conditions under well-watered(WW) and water-stressed(WS) conditions. In both water regimes,‘Changhan 58' showed a significantly higher ear photosynthetic rate with a lower rate of variation and a significantly higher percentage variation of transpiration compared to control plants at the heading stage under WS conditions than did ‘Xinong 9871' plants. Moreover,‘Changhan 58' showed lower stomatal density(SD) and higher stomatal area per unit organ area(A) under both water conditions. Water stress decreased SD, A, and stomatal width(SW), and increased stomatal length in flag leaves(upper and lower surfaces) and ear organs(awn, glume,lemma, and palea), with the changes more pronounced in ear organs than in flag *** WUE increased slightly, while integral WUE improved significantly in both cultivars. Integral WUE was higher in ‘Changhan 58', and increased by a greater amount, than in‘Xinong 9871'. These results suggest that drought resistance in ‘Changhan 58' is regulated by stomatal characteristics through a decrease in transpiration rate in order to improve integral WUE and photosynthetic performance, and through sustaining a higher ear photosynthetic rate, therefore enhancing overall drought-resistance.

关键词： Wheat Stomatal structure Ear photosynthesis Drought resistance Water use efficiency