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Insight into the role of ethylene glycol on thermodynamics and nucleation kinetics of dimethyl terephthalate in mixed solvent system

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Particuology 2024年第2期85卷 1-12页

作者： Yujin Zhang Chunyan Shi Jing Tang li liu Dongxia Yan Qing Zhou Xingmei Lu songyan Jia College of Chemical Engineering Shenyang University of Chemical TechnologyShenyang110142China Bejing Key Laboratoryoflonic liquids Clean Process CAS Key LaboratoryofGreen Process and EngineeringState Key Laboratoryof Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemistry and Chemical Engineering Qingdao UniversityQingdao266071China Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou450001China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

Dissolution and nucleation are two essential processes for industrial crystallization.This paper in-vestigates the effect of ethylene glycol addition on the crystallization behavior of dimethyl terephthalate(DMT)in solution.The DMT solubility in mixed solvent system(methanol-ethylene glycol)was deter-mined by isothermal satiation approach,and the solubility was associated using seven models.The model fitting results were consistent with the experimental values.Based on the results,the metastable zone width(MSZW)of DMT was detected by the polythermal approach;the modified Sangwal's theory was used to investigate the nucleation behavior,which can provide a new way of thought for better analysis of the crystallization behavior.The results demonstrated that MSZW was associated with various elements,such as cooling rate,saturation temperature and mass fraction of ethylene glycol.The addition of ethylene glycol slowed down the nucleation rate as shown by the broadening of MSZW.We derive the solid-liquid interface energy,the nucleation driving force,the critical nucleation size and the critical Gibbs free energy according to the classical nucleation theory.It is demonstrated that the nucleation driving force and the solid-liquid interface energy are dependent and jointly influence the MSZW.

关键词： Dissolution Nucleation Solubility Apparent thermodynamic parameters Metastable zone width Solid-liquid interface energy

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Cu nanowire array with designed interphases enabling high performance Si anode toward flexible lithium-ion battery

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Nano Research 2024年第3期17卷 1516-1524页

作者： Pengfei Su Ziqi Zhang linshan Luo Zhiyong Zhang Chaofei Lan Yahui li Shaowen Xu Shanpeng Pei Guangyang lin Cheng li Xiang Han Wei Huang songyan Chen Fujian Provincial Key Laboratory of Semiconductors and Applications Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient DevicesDepartment of PhysicsXiamen UniversityXiamen 361005China College of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037China Science and Technology on Analog Integrated Circuit Laboratory Chongqing 400060China Shandong Electric Power Engineering Consulting Institute Co. Ltd.Jinan 250013China

To meet the growing demand for wearable smart electronic devices,the development of flexible lithium-ion batteries(liBs)is essential.Silicon is an ideal candidate for the anode material of flexible lithium-ion batteries due to its high specific capacity,low working potential,and earth abundance.The largest challenge in developing a flexible silicon anode is how to maintain structural integrity and ensure stable electrochemical reactions during external deformation.In this work,we propose a novel design for fabricating core–shell electrodes based on a copper nanowire(CuNW)array core and magnetron sputtered Si/C shell.The nanowire array structure has characteristics of bending under longitudinal stress and twisting under transverse stress,which helps to maintain the mechanical stability of the structure during electrode bending and cycling.The low-temperature annealing generates a small amount of Cu3Si alloy,which enhances the connection strength between Si and the conductive network and solves the poor conductivity problem of Si,which is known as a semiconductor material.This unique configuration design of CuNW@Si@C-400℃ leads to stable long cycle performance of 1109 mAh∙g^(-1) after 1000 cycles and excellent rate performance of 500 mAh∙g^(-1) at a current density of 10 A∙g^(-1).Furthermore,the CuNW@Si@C-400℃||liFePO_(4)(LFP)full battery demonstrates excellent flexibility,with a capacity retention of more than 96%after 100 bends.This study provides a promising strategy for the development of flexible lithium-ion batteries.

关键词： flexible lithium-ion battery silicon anode magnetron sputtering core–shell electrode Cu nanowire array

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Low soil C:N ratio results in accumulation and leaching of nitrite and nitrate in agricultural soils under heavy rainfall

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Pedosphere 2023年第6期33卷 865-879页

作者： Xiaosong YANG Zhengyi HU Zijian XIE songyan li Xiaolei SUN Xianlin KE Mingming TAO Resource and Environmental College University of Chinese Academy of SciencesBeijing 100049China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China National Engineering Laboratory for Lake Pollution Control and Ecological Restoration Chinese Research Academy of Environmental SciencesBeijing 100012China Institute of Bio-and Geosciences Agrosphere(IBG-3)Forschungszentrum JulichJulich 52425Germany

Nitrate (NO-3) and nitrite (NO2-) leaching threatens groundwater quality.Soil C:N ratio,i.e.,the ratio of soil organic carbon to total nitrogen,affects mineralization,nitrification,and denitrification;however,its mechanism for driving soil NO-3and NO-2accumulation and leaching remains unclear.Here,a field investigation in a fluvo-aquic soil and a soil column experiment were performed to explore the relationships between soil C:N ratio and soil NO-3and NO-2leaching in three soil layers (0–20,20–40,and 40–60 cm) under heavy rainfall (rainfall rate>25 mm d-1).The field investigation results showed that both soil NO-3-N and NO-2-N contents decreased exponentially (Pling showed that the high NO-3and NO-2levels at low soil C:N ratio might be attributed to the inhibition of NO-3reduction (i.e.,low narG gene) and NO-2oxidation (i.e.,low Nitrospira) and thus the accumulation of soil NO-3and NO-2,respectively.Therefore,the leaching of NO-2and NO-3in low C:N soils requires more attention during the rainy sea

关键词： ammonia-oxidizing bacteria ammonifying bacteria functional gene microbial community nitrite-oxidizing bacteria

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On the source of the quasi-Carrington Rotation periodic magnetic variations on the Martian surface: InSight observations and modeling

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Earth and Planetary Physics 2022年第3期6卷 275-283页

作者： Hao Luo AiMin Du ShaoHua Zhang YaSong Ge Ying Zhang ShuQuan Sun lin Zhao lin Tian songyan li Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth Science University of Chinese Academy of SciencesBeijing 100049China Beijing Institute of Spacecraft Environment Engineering Beijing 100094China

In a recent paper(Luo H et al.,2022),we found that the peak amplitudes of diurnal magnetic variations,measured during martian days(sols)at the InSight landing site,exhibited quasi Carrington-Rotation(qCR)periods at higher eigenmodes of the natural orthogonal components(NOC);these results were based on~664 sols of magnetic field measurements.However,the source of these periodic variations is still unknown.In this paper we introduce the neutral-wind driven ionospheric dynamo current model(e.g.,lillis et al.,2019)to investigate the source.Four candidates-the draped IMF,electron density/plasma density,the neutral densities,and the electron temperature in the ionosphere with artificial qCR periodicity,are applied in the modeling to find the main factor likely to be causing the observed surface magnetic field variations that exhibit the same qCR periods.Results show that the electron density/plasma density,which controls the total conductivity in the dynamo region,appears to account for the greatest part of the surface qCR variations;its contribution reaches about 67.6%.The draped IMF,the neutral densities,and the electron temperature account,respectively,for only about 12.9%,10.3%,and 9.2%of the variations.Our study implies that the qCR magnetic variations on the Martian surface are due primarily to variations of the dynamo currents caused by the electron density variations.We suggest also that the timevarying fields with the qCR period could be used to probe the Martian interior's electrical conductivity structure to a depth of at least 700 km.

关键词： InSight sol magnetic variations Carrington Rotation(CR)periodicity

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基于高干度泡沫实验的非均质咸水层CO_(2)封存能力分析

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天然气工业 2024年第4期44卷 46-55页

作者：李松岩马芮党法强中国石油大学(华东)石油工程学院

CO_(2)咸水层封存是实现“碳中和”目标的一项重要技术手段。高干度泡沫不仅能更好地控制CO_(2)流度而且还能适应地层的非均质性,明显提高了咸水层的空间利用效率。为探究高干度CO_(2)泡沫在非均质咸水层中的调剖效果与CO_(2)封存能力,... 详细信息

CO_(2)咸水层封存是实现“碳中和”目标的一项重要技术手段。高干度泡沫不仅能更好地控制CO_(2)流度而且还能适应地层的非均质性,明显提高了咸水层的空间利用效率。为探究高干度CO_(2)泡沫在非均质咸水层中的调剖效果与CO_(2)封存能力,利用自行设计的高温高压驱替实验装置,进行了不同渗透率级差的并联岩心CO_(2)泡沫驱室内实验研究,分析了驱替过程中岩心的气液产出情况与CO_(2)饱和度的变化规律,指出了不同渗透率级差非均质岩心模型的碳封存效果与机理。研究结果表明:①与CO_(2)气驱相比高干度泡沫驱用于CO_(2)咸水层埋存具有更大优势,当岩心渗透率级差介于2.6~10.8时,泡沫均能有效封堵高渗透岩心,使阻力因子维持在36左右,增大了驱替压差与低渗透岩心的产气、产液速度;②岩心中气相饱和度与渗透率存在一定关系,当岩心的渗透率小于2450 mD时,最高气相饱和度随渗透率增加而增大,当渗透率超过2450 mD时,岩心最高气相饱和度在80%左右;③采用高干度泡沫驱可以有效扩大岩心中CO_(2)封存量,渗透率级差为4时,泡沫驱的CO_(2)封存体积较气驱增长219%,当渗透率级差扩大至10.8,CO_(2)封存量能始终维持在较高水平。结论认为,咸水层条件下CO_(2)泡沫驱替实验探究了CO_(2)封存能力变化,提供了非均质储层提高碳封存效率的实验认识,可为非均质咸水层中CO_(2)的地质封存技术优化提供参考和借鉴。

关键词：碳中和 CO_(2)地质封存高干度泡沫咸水层非均质地层封存效率

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Implications of Stahl's Theorems to Holomorphic Embedding Part I: Theoretical Convergence

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CSEE Journal of Power and Energy Systems 2021年第4期7卷 761-772页

作者： songyan li Daniel Tylavsky Di Shi Zhiwei Wang School of Electrical Computer and Energy Engineering in Arizona State University TempeAZ 85287USA AINERGY LLC Santa ClaraCA 95051 State Grid Jiangsu Electric Power Company Nanjing 210024China

What is known as StahPs Theorem in power engineering circles is used to justify a convergence guarantee of the Holomorphic Embedding Method(HEM)as it applies to powerflow(PF)problem.In this two-part paper,we examine in more detail the implications of Stahl's theorems to both theoretical and numerical convergence for a wider range of problems to which these theorems are now being applied.We show that the difference between StahPs extremal domain and the function's domain is responsible for theoretical nonconvergence and that the fundamental cause of numerical nonconvergence is the magnitude of logarithmic capacity of the branch cut,a concept central to understanding nonconvergence.We introduce theorems using the necessary mathematical parlance and then translate the language to show its implications to convergence of nonlinear problems in general and specifically to the PF problem.We show that,among other possibilities,the existence of Chebotarev points,which are embedding specific,are a possible theoretical impediment to convergence・The theoretical foundation of Part I is necessary for understanding the numerical behavior of HEM discussed in Part II.

关键词： Analytic continuation holomorphic embedding method power flow Pade approximants HEM Stahl's theorems

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Dynamic simulation and safety evaluation of high-speed trains meeting in open air

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Acta Mechanica Sinica 2016年第2期32卷 206-214页

作者： songyan li Zhijun Zheng Jilin Yu Chunqiang Qian CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China

Dynamic responses of a carriage under excitation with the German high-speed low-interference track spectrum together with the air pressure pulse generated as high-speed trains passing each other are investigated with a multi-body dynamics method.The variations of degrees of freedom（DOFs：horizontal movement,roll angle,and yaw angle）,the lateral wheel-rail force,the derailment coefficient and the rate of wheel load reduction with time when two carriages meet in open air are obtained and compared with the results of a single train travelling at specifie speeds.Results show that the rate of wheel load reduction increases with the increase of train speed and meets some safety standard at a certain speed,but exceeding the value of the rate of wheel load reduction does not necessarily mean derailment.The evaluation standard of the rate of wheel load reduction is somewhat conservative and may be loosened.The pressure pulse has significan effects on the train DOFs,and the evaluations of these safety indexes are strongly suggested in practice.The pressure pulse has a limited effect on the derailment coefficien and the lateral wheel-rail force,and,thus,their further evaluations may be not necessary.

关键词： High-speed train Pressure pulse Derailment Dynamics simulation Safety standard

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Asymmetrical Diffusion-Induced Directional Motion

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Communications in Theoretical Physics 2004年第5X期42卷 707-710页

作者： BAOJing-Dong WANGHai-Yan songyan-li TheKeyLaboratoryofBeamTechniqueandMaterialModificationoftheMinistryofEducation BeijingNormalUniversityBeijing100875China DepartmentofPhysics BeijingNormalUniversityBeijing100875China

Competition between anomalous diffusion and normal diffusion along two different directions of the track for a Brownian motor, combined with a periodic potential flashing, can lead to a macroscopic motion. The current is calculated analytically by using the Astumian-Bier's approach of the step number per cycle. It is shown that the direction of current occurs reversal for different waiting times of the potential off and the magnitude of current is prominently enhanced. Moreover, a thermal "green" noise is proposed to produce the ballistic diffusion, numerical simulations for the average velocity of the particle in the presence of ballistic and normal diffusions support the present theoretical findings.

关键词：不平衡波动不对称结构对称分布时间周期偏微分方程

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Implications of Stahl's Theorems to Holomorphic Embedding Part II: Numerical Convergence

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CSEE Journal of Power and Energy Systems 2021年第4期7卷 773-784页

作者： Abhinav Dronamraju songyan li Qirui li Yuting li Daniel Tylavsky Di Shi Zhiwei Wang School of Electrical Computer and Energy Engineering in Arizona State University TempeAZ 85287USA Southwest Electric Power Design Institute Co. Ltd.of China Siemens 8850 Fallbrook Dr.HoustonTexas 77064United States AINERGY LLC Santa ClaraCA 95051 State Grid Jiangsu Electric Power Company Nanjing 210024China

What has become known as Stahl's Theorem in power-engineering circles has been used to justify a convergence guarantee of the Holomorphic Embedding Method(HEM)as it applies to the power-flow problem.In this,the second part of a two-part paper,we examine implications to numerical convergence of the HEM and the numerical properties of a Pade approximant algorithm.We show that even if the point of interest is within the convergence domain,numerical convergence of the sequence of Pade approximants computed with finite precision is not guaranteed.We propose a convergence factor equation that can be used to both estimate the convergence rate and the capacity of the branch cut.We also show that the study of convergence properties of the Pade approximant is the study of the location of the branch-points of the function,which in turn dictate branch-cut topology and capacity and,therefore,convergence rate.

关键词： Analytic continuation HEM holomorphic embedding method power flow Pade approximants StahPs theorems

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Asymmetry of Coordinate and Velocity in Noisy Oscillator

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Communications in Theoretical Physics 2005年第1期43卷 97-101页

作者： songyan-li BAOJing-Dong WANGHai-Yan JIQing DepartmentofPhysics BeijingNormalUniversityBeijing100875China DepartmentofPhysics BeijingNormalUniversityBeijing100875China／／TheKeyLaboratoryofBeamTechniqueandMaterialModificationofMinistryofEducationBeijingNormalUniversityBeijing100875China DepartmentofPhysics HebeiUniversityofTechnologyTianjin300130China

The velocity variable of a noise oscillator as an internal or external noise is proposed, the spectrum of which is quite different from that of the coordinate variable of the same noise oscillator. The former leads to ballistic diffusion for a free particle in long time limit and the asymptotical results of the system are sensitive to the initial condition. However, diffusion process induced by the coordinate of noise oscillator is a normal one and depends on the initial condition only in the transient time. This allows us to classify two kinds of non-Markovian processes: normal one and strong one, just like the processes induced by the coordinate and the velocity of noise oscillator, respectively.Applying to a correlation ratchet, we have found that the steady current of a particle subjected to the velocity of noise oscillator is opposite to that subjected to its coordinate, thus the former shows greenness and the latter redness.

关键词：行进噪音坐标噪音冲击扩散非马尔可夫Langevin方程关联棘轮

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