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Mathematical and Experimental Investigation of Water Migration in Plant Xylem

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Journal of Bionic Engineering 2017年第4期14卷 622-630页

作者： jiaju hong Sheng Liu Paul Glover Shenyi Wu Yuying Yan Fluids & Thermal Engineering Group Faculty of Engineering University of Nottingham Nottingham NG7 2RD UK Marine Engineering College Dalian Maritime University Dalian 116026 China College of Mechanical and Electrical Engineering Hohai University Changzhou 213022 China School of Physics University of Nottingham Nottingham NG7 2RD UK Fluids & Thermal Engineering Research Centre University of Nottingham Ningbo Ningbo 315100 China

Plant can take water from soil up to several metres high. However, the mechanism of how water rises against gravity is still controversially discussed despite a few mechanisms have been proposed. Also, there still lacks of a critical transportation model because of the diversity and complex xylem structure of plants. This paper mainly focuses on the water transport process within xylem and a mathematical model is presented. With a simplified micro channel from xylem structure and the calculation using the model of water migration in xylem, this paper identified the relationship between various forces and water migration velocity. The velocity of water migration within the plant stem is considered as detail as possible using all major forces involved, and a full mathmetical model is proposed to calculate and predict the velocity of water migration in plants. Using details of a specific plant, the velocity of water migration in the plant can be calculated, and then compared to the experimental result from Magnetic Resonance Imaging （MRI）. The two results match perfectly to each other, indicating the accuracy of the mathematical model, thus the mathematical model should have brighter furore in further applications.

关键词： plant water migration mathematical model MRI bionic

Observation of accurately designed bound states in the continuum in momentum space

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Photonics Research 2024年第4期12卷 638-647页

作者： jiaju WU JINGGUANG CHEN XIN QI ZHIWEI GUO jiajuN WANG FENG WU YONG SUN YUNHUI LI HAITAO JIANG LEI SHI JIAN ZI hong CHEN MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghai 200433China School of Optoelectronic Engineering Guangdong Polytechnic Normal UniversityGuangzhou 510665China

Bound states in the continuum(BICs)in artificial photonic structures have received considerable attention since they offer unique methods for the extreme field localization and enhancement of light-matter ***,the symmetry-protected BICs are located at high symmetric points,while the positions of accidental BICs achieved by tuning the parameters will appear at some points in momentum *** to now,to accurately design the position of the accidental BIC in momentum space is still a ***,we theoretically and experimentally demonstrate an accurately designed accidental BIC in a two-coupled-oscillator system consisting of bilayer gratings,where the optical response of each grating can be described by a single resonator *** changing the interlayer distance between the gratings to tune the propagation phase shift related to wave vectors,the position of the accidental BIC can be arbitrarily controlled in momentum ***,we present a general method and rigorous numerical analyses for extracting the polarization vector fields to observe the topological properties of BICs from the polarization-resolved transmission ***,an application of the highly efficient second harmonic generation assisted by quasi-BIC is *** work provides a straightforward strategy for manipulating BICs and studying their topological properties in momentum space.

关键词： polarization tuning resonator

Observation of maximal intrinsic chirality empowered by dual quasi-bound states in the continuum in a planar metasurface

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Photonics Research 2024年第2期12卷 244-252页

作者： XIN QI jiaju WU FENG WU SONG ZHAO CHAO WU YUEYANG MIN MINA REN YUFEI WANG HAITAO JIANG YUNHUI LI ZHIWEI GUO YAPING YANG WANHUA ZHENG hong CHEN YONG SUN MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China School of Optoelectronic Engineering Guangdong Polytechnic Normal UniversityGuangzhou 510665China l3 Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Electrical Engineering Tongji UniversityShanghai 201804China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional *** this paper,we propose a planar metasurface capable of generating maximal intrinsic chirality and achieving dual-band spinselective transmission utilizing dual quasi-bound states in the continuum(quasi-BICs)caused by the structural symmetry ***,the value of circular dichroism(CD)and the transmittance of two kinds of circular polarization states can be arbitrarily controlled by tuning the asymmetry *** CD approaching unity with the maximum transmittance up to 0.95 is experimentally achieved in the dual ***,assisted by chiral BICs,the application in polarization multiplexed near-field image display is also *** work provides a new avenue to flexibly control intrinsic chirality in planar structure and offers an alternative strategy to develop chiral sensing,multiband spin-selective transmission,and high-performance circularly polarized wave *** basic principle and design method of our experiments in the microwave regime can be extended to other bands,such as the terahertz and infrared wavelengths.

关键词： planar intrinsic quasi

Plant type effect overweighs seasonal variation in n-alkanoic acid biomarker on regional Loess Plateau of China

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Science China Earth Sciences 2024年第8期67卷 2547-2562页

作者： Jinzhao LIU S.Nemiah LADD jiaju ZHAO Dongna YAN Ding HE Yunning CAO Zhisheng AN State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China CAS Center for Excellence in Quaternary Science and Global Change Xi’an 710061China Department of Environmental Sciences University of BaselBasel 4056Switzerland Department of Ocean Science and Center for Ocean Research in hong Kong and Macao The Hong Kong University of Science and TechnologyHong Kong 999077China

The effect of plant type on n-alkane biomarker has been widely studied,but the influence of plant type on n-alkanoic acids(n-FAs)has received less *** the effect of the distribution of n-FAs and their hydrogen isotope composition(δ^(2)H_(FA))is critical for interpreting sedimentaryδ^(2)H_(FA)values as proxies of hydroclimate and/or vegetation *** this study,we systematically investigated the distribution ofn-FAs andδ^(2)H_(FA)values across seasons on the Chinese Loess Plateau(CLP).Our results showed that there were no significant seasonal differences in n-FAs distribution andδ^(2)H_(FA)values,but there were significant differences inδ^(2)H_(FA)values across plant ***δ^(2)H_(FA)values ranged from-185‰to-125‰in dicots(-161‰±28‰),and from-215‰to-170‰in monocots(-196‰±22‰)on the *** fractionation betweenδ^(2)H_(FA)values and precipitationδ^(2)H(ε_(FA-P))was also^(2)H-enriched in dicots relative to *** the regional scale of the CLP,δ^(2)H_(FA)values were not correlated withδ^(2)H values of ***,δ^(2)H_(FA)values from the CLP were similar to expectations from a global comparison,both in terms of their mean values and high variability among plants growing in sites with similarδ^(2)H values of *** some of this variability inεFA-Pis due to the effect of plant type,a careful assessment of the likely sources of waxes in terrestrial sediments is critical when usingδ^(2)H_(FA)values for paleohydroclimate reconstruction.

关键词： n-Alkanoic acid Hydrogen isotope Plant type Paleohydroclimate Chinese Loess Plateau

摇摆对TFE-TEGDME降膜吸收影响的可视化实验研究

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制冷学报 2019年第2期40卷 142-147页

作者：高洪涛孙玮廷祖德洲洪嘉驹大连海事大学制冷与低温工程研究所大连116026

本文搭建以TFE-TEGDME溶液为制冷工质对的摇摆吸收式制冷实验台,对竖直管降膜吸收器进行可视化实验研究。静止状态下实验表明:当溶液质量流量为0.1～0.2 kg/min时,液膜呈层流和单色波状态;当流量为0.5 kg/min和0.8 kg/min时,液膜表面出... 详细信息

本文搭建以TFE-TEGDME溶液为制冷工质对的摇摆吸收式制冷实验台,对竖直管降膜吸收器进行可视化实验研究。静止状态下实验表明:当溶液质量流量为0.1～0.2 kg/min时,液膜呈层流和单色波状态;当流量为0.5 kg/min和0.8 kg/min时,液膜表面出现稳定波状流与合并波状流;当质量流量为1.2 kg/min时,液膜出现脱落现象。在不同波形下吸收器的吸收效果差别很大。摇摆状态下实验表明:随着摇摆幅度的增大或摇摆周期的减小,液膜受到的扰动越大,当摇摆幅度达到15°或摇摆周期达到4 s时将出现合并波状流和脱落现象;在同一个摇摆幅度和周期下,液膜在摆幅边缘受到扰动较大,在摆幅中间流动较为平缓;当溶液质量流量为0.28 kg/min时,在摇摆幅度为8°或摇摆周期为10 s时系统COP最大,而当质量流量为0.14 kg/min时,COP峰值出现在摇摆幅度10°或摇摆周期8 s时,同时说明溶液质量流量更大时液膜受到摇摆的扰动就更大。

关键词：吸收式制冷摇摆状态降膜波形可视化

基于有限元方法的溴化锂降膜吸收传热传质的数值研究

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热科学与技术 2021年第3期20卷 238-245页

作者：毛菲高洪涛余立东宋玉超洪嘉驹大连海事大学制冷与低温工程研究所辽宁大连116026

吸收器是吸收式制冷系统的重要部件。溴化锂溶液的降膜吸收是吸收器中最常见的传质传热形式之一。通过对溴化锂溶液在降膜吸收过程中传质和传热特性的分析,使用基于有限元法的COMSOL Multiphysics软件,建立了溴化锂溶液和水蒸汽降膜吸... 详细信息

吸收器是吸收式制冷系统的重要部件。溴化锂溶液的降膜吸收是吸收器中最常见的传质传热形式之一。通过对溴化锂溶液在降膜吸收过程中传质和传热特性的分析,使用基于有限元法的COMSOL Multiphysics软件,建立了溴化锂溶液和水蒸汽降膜吸收的物理数学模型,计算了液膜内部温度和质量分数的分布、界面处传质通量、界面处传热通量、传质传热速率和液相传质传热系数。根据计算结果分析了喷淋密度对平均传质通量、平均传热通量和平均传质传热系数的影响。结果表明:平均传质系数和平均传热系数均随着喷淋密度的增大而增大;平均传质通量和平均传热通量均随喷淋密度的增大而先增后减。

关键词：溴化锂溶液降膜吸收传热传质有限元方法

Steerable merging bound states in the continuum on a quasi-flatband of photonic crystal slabs without breaking symmetry

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光子学研究:英文版 2023年第7期11卷 1262-1274页

作者： XIN QI jiaju WU FENG WU MINA REN QIAN WEI YUFEI WANG HAITAO JIANG YUNHUI LI ZHIWEI GUO YAPING YANG WANHUA ZHENG YONG SUN hong CHEN MOE Key Laboratory of Advanced Micro-structured Materials School of Physics Sciences and EngineeringTongji UniversityShanghai 200092China School of Optoelectronic Engineering Guangdong Polytechnic Normal UniversityGuangzhou 510665China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Department of Electrical Engineering Tongji UniversityShanghai 201804China

Optical resonators with high quality(Q)factors are paramount for the enhancement of light–matter interactions in engineered photonic structures,but their performance always suffers from the scattering loss caused by fabrication *** bound states in the continuum(BICs)provide us with a nontrivial physical mechanism to overcome this challenge,as they can significantly improve the Q factors of ***,most of the reported merging BICs are found atΓpoint(the center of the Brillouin zone),which intensively limits many potential applications based on angular *** date,studies on manipulating merging BICs at off-Γpoint are always accompanied by the breaking of structural symmetry that inevitably increases process difficulty and structural defects to a certain ***,we propose a scheme to construct merging BICs at almost an arbitrary point in momentum space without breaking *** by the topological features of BICs,we merge four accidental BICs with one symmetry-protected BIC at theΓpoint and merge two accidental BICs with opposite topological charges at the off-Γpoint only by changing the periodic constant of a photonic crystal ***,the position of off-Γmerging BICs can be flexibly tuned by the periodic constant and height of the structure ***,it is observed that the movement of BICs occurs in a quasi-flatband with ultra-narrow ***,merging BICs in a tiny band provide a mechanism to realize more robust ultrahigh-Q resonances that further improve the optical performance,which is limited by wide-angle ***,as an example of application,effective angle-insensitive second-harmonic generation assisted by different quasi-BICs is numerically *** findings demonstrate momentum-steerable merging BICs in a quasi-flatband,which may expand the application of BICs to the enhancement of frequency-sensitive light–matter interaction with angular selectivit

关键词： quasi symmetry breaking

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高压侧电压控制对电压稳定性的影响

高电压技术 2005年第11期31卷 83-84,87页

作者：周晓渊邱家驹周宏浙江大学电气工程学院杭州310027 华中电网有限公司武汉430072

简要介绍了发电厂高压侧电压控制原理和特性,并根据简化的发电机模型,应用特征根方法分析了HS-VC对一单机—恒功率负荷系统电压稳定性的影响,分析表明,高压侧电压控制可有效改善系统电压稳定性,改善程度和电压控制点位置α有关,α越大,... 详细信息

简要介绍了发电厂高压侧电压控制原理和特性,并根据简化的发电机模型,应用特征根方法分析了HS-VC对一单机—恒功率负荷系统电压稳定性的影响,分析表明,高压侧电压控制可有效改善系统电压稳定性,改善程度和电压控制点位置α有关,α越大,控制点越接近高压侧,改善效果越好。实际系统算例的时域仿真验证了分析的正确性。

关键词：高压侧电压控制电压稳定单机-单负荷系统

Non-peripherally octaalkyl-substituted nickel phthalocyanines used as non-dopant hole transport materials in perovskite solar cells

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Chinese Physics B 2021年第10期30卷 698-704页

作者： Fei Qi Bo Wu Junyuan Xu Qian Chen Haiquan Shan jiaju Xu Zong-Xiang Xu Department of Chemistry Southern University of Science and TechnologyShenzhen 518000China Guangdong-hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices Southern University of Science and TechnologyShenzhen 518000China

This report presents two non-perihperally octaalkyl-substituted nickel phthalocyanines(NiPcs),namely,NiEt2Pc and NiPr_(2)Pc,for use as dopant-free hole transport materials in perovskite solar cells(PSCs).The length extension of the alkyl chains from ethyl to propyl significantly tunes the NiPcs’energy levels,thus reducing charge carrier recombination at the perovskite/hole transport layer(HTL)interface and leading to higher open-circuit voltage(VOC)and short-circuit current density(JSC)observed for the NiPr_(2)Pc-based *** higher charge carrier mobility,higher thin film crystallinity,and lower surface roughness of the NiPr_(2)Pc HTL compared with that of the NiEt2Pc one also lead to higher JSC and fill factor(FF)observed for the NiPr_(2)Pc-based ***,the NiPr_(2)Pc-based PSC exhibits a higher power conversion efficiency(PCE)of 14.07%than that of the NiEt2Pc-based device(8.63%).

关键词： perovskite solar cells metal phthalocyanines hole transport layers