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Low-cost portable dielectric spectrometer based on mini-vector network analyzer and open-ended coaxial probe technology

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 166-172页

作者： zhuozhuo zhu Xinhua zhu Wenchuan Guo College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100ShaanxiChina School of Physics and Electronic Information Yan'an UniversityYan'an 716000ShaanxiChina Shaanxi Research Center of Agricultural Equipment Engineering Technology Yangling 712100ShaanxiChina Key Laboratory of Agricultural Internet of Things Ministry of Agriculture and Rural AffairsYangling 712100ShaanxiChina Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service Yangling 712100ShaanxiChina

As a simple,fast,and non-destructive measuring technology,dielectric spectroscopy is usually used to analyze the dielectric properties of agricultural products and food,and then to predict the main components of ***,the large and expensive vector network analyzers(VNA)with expensive analysis software applied in measuring dielectric properties make research limited to the *** acquire dielectric spectra in situ,a model for solving relative complex permittivity was derived,and its performance was ***,a low-cost portable dielectric spectrometer with a mini VNA,a Raspberry Pi,and a coaxial probe as core parts was developed over the frequency range of 1.0-3000 *** stability and accuracy of the developed spectrometer were tested using milk and *** results indicated that the relative errors of the model were within±5%for dielectric constant(ε′)and loss factor(ε″).The coefficients of variation of measuredε′andε″by the developed spectrometer at 1.0-3000 MHz were less than 1.and 2%,*** with the dielectric properties obtained by using a commercial dielectric measurement system,the relative errors of measuredε′andε″were within±3.4%and±6.0%,*** study makes fast,non-destructive,and on-site food quality detection using dielectric spectra possible.

关键词： coaxial probe mini vector network analyzer low-cost portable dielectric spectrometer

Arthropod trace fossils from the zhujiaqing Formation (Meishucunian, Yunnan) and their palaeobiological implications

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Progress in Natural Science:Materials International 2003年第10期 75-80页

作者： Bernd WEBER 1.* and zhu Maoyan 2 (1. Freie Universitt Berlin, Institut für Geologische Wissenschaften, Fachrichtung Geologie, Ackerstraβe 71.76, D 1.355 Berlin, Germany 2. LPS, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 21.008, China) Freie Universit Berlin Institut für Geologische Wissenschaften Fachrichtung Geologie Ackerstraβe 71～76 D-13355 Berlin Germany LPS Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China

Along with several non arthropod ichnotaxa and rather non specific scratchmarks, the Upper Phosphate of the zhujiaqing Formation (Early Meishucunian Stage) in Eastern Yunnan yielded well preserved resting and digging traces of the Rusophycus type interpreted as resting traces of unknown large arthropods (ca. 3～6 cm in length). The discernible morphological details of these trace fossils enable a rough estimation of the body plan characteristics of the trace originators placing the latter doubtless into the early arthropods, if not euarthropods. The spectrum of the Meishucunian ichnoassemblage, especially the different types of arthropod repichnia point to the existence of a complex benthic ecosystem consisting of animals with different behavioural patterns and life styles already during the earliest Cambrian (Nemakit Daldyn), and demands the assumption of a longer evolutionary past history of the benthic life on earth before the so called “Cambrian Explosion” of the metazoans.

关键词： Meishucunian Stage arthropods ichnofauna arthropod evolution Precambrian Cambrian Boundary Yangtze Platform.

Wood of trees:Cellular structure,molecular formation,and genetic engineering

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Journal of Integrative Plant Biology 2024年第3期66卷 443-467页

作者： Yingying zhu Laigeng Li State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems and College of Ecology Lanzhou UniversityLanzhou 730000China National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032China

Wood is an invaluable asset to human society due to its renewable nature,making it suitable for both sustainable energy production and material ***,wood derived from forest trees plays a crucial role in sequestering a significant portion of the carbon dioxide fixed during photosynthesis by terrestrial ***,with the expansion of the global population and ongoing industrialization,forest coverage has been substantially decreased,resulting in significant challenges for wood production and *** production practices have changed away from natural forests toward plantation ***,understanding the underlying genetic mechanisms of wood formation is the foundation for developing high-quality,fast-growing plantation *** ideal forest trees for wood production using genetic technologies has attracted the interest of *** studies have been carried out in recent years on the molecular,genetic,and cell-biological mechanisms of wood formation,and considerable progress and findings have been *** studies and findings indicate enormous possibilities and prospects for tree *** review will outline and assess the cellular and molecular mechanisms of wood formation,as well as studies on genetically improving forest trees,and address future development prospects.

关键词： cambium cell wall Populus wood formation xylem

Controllable chemical redox reactions to couple microbial degradation for organic contaminated sites remediation:A review

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Journal of Environmental Sciences 2024年第5期139卷 428-445页

作者： Bin Chen Jiang Xu Lizhong zhu College of Environmental and Resource Sciences Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Zhejiang UniversityHangzhou 310058China Zhejiang Agriculture&Forest University Lin'an 311300China

Global environmental concern over organic contaminated sites has been progressively conspicuous during the process of urbanization and industrial *** traditional physical or chemical remediation technologies may significantly destroy the soil structure and function,coupling moderate chemical degradation with microbial remediation becomes a potential way for the green,economic,and efficient remediation of contaminated ***,this work systematically elucidates why and how to couple chemical technology with microbial remediation,mainly focused on the controllable redox reactions of organic *** rational design of materials structure,selective generation of reactive oxygen species,and estimation of degradation pathway are described for chemical ***,current progress on efficient and selective reductions of organic contaminants(i.e.,dechlorination,defluorination,-NO_(2) reduction)is *** with the microbial remediation of contaminated sites,several consideration factors of how to couple chemical and microbial remediation are proposed based on both fundamental and practical points of *** review will advance the understanding and development of chemical-microbial coupled remediation for organic contaminated sites.

关键词： Soil remediation Groundwater remediation Rational design Reactive species Environmental nanotechnology

Incorporating contextual evidence to improve implicit discourse relation recognition in Chinese

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Frontiers of Computer Science 2024年第3期18卷 91-104页

作者： Sheng XU Peifeng LI Qiaoming zhu School of Computer Science and Technology Soochow UniversitySuzhou 215000China

The discourse analysis task,which focuses on understanding the semantics of long text spans,has received increasing attention in recent *** a critical component of discourse analysis,discourse relation recognition aims to identify the rhetorical relations between adjacent discourse units(e.g.,clauses,sentences,and sentence groups),called arguments,in a *** works focused on capturing the semantic interactions between arguments to recognize their discourse relations,ignoring important textual information in the surrounding ***,in many cases,more than capturing semantic interactions from the texts of the two arguments are needed to identify their rhetorical relations,requiring mining more contextual *** this paper,we propose a method to convert the RST-style discourse trees in the training set into dependency-based trees and train a contextual evidence selector on these transformed *** this way,the selector can learn the ability to automatically pick critical textual information from the context(i.e.,as evidence)for arguments to assist in discriminating their *** we encode the arguments concatenated with corresponding evidence to obtain the enhanced argument ***,we combine original and enhanced argument representations to recognize their *** addition,we introduce auxiliary tasks to guide the training of the evidence selector to strengthen its selection *** experimental results on the Chinese CDTB dataset show that our method outperforms several state-of-the-art baselines in both micro and macro F1.scores.

关键词： discourse parsing discourse relation recognition contextual evidence selection

Dynamic characteristics of multi-span spinning beams with elastic constraints under an axial compressive force

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 295-310页

作者： Xiaodong GUO zhu SU Lifeng WANG State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is *** displacement and bending angle functions are represented through an improved Fourier series,which ensures the continuity of the derivative at the boundary and enhances the *** exact characteristic equations of the multi-span spinning beams with elastic constraints under an axial compressive force are derived by the Lagrange *** efficiency and accuracy of the present method are validated in comparison with the finite element method(FEM)and other *** effects of the boundary spring stiffness,the number of spans,the spinning velocity,and the axial compressive force on the dynamic characteristics of the multi-span spinning beams are *** results show that the present method can freely simulate any boundary constraints without modifying the solution *** elastic range of linear springs is larger than that of torsion springs,and it is not affected by the number of *** an increase in the axial compressive force,the attenuation rate of the natural frequency of a spinning beam with a large number of spans becomes larger,while the attenuation rate with an elastic boundary is lower than that under a classic simply supported boundary.

关键词： multi-span spinning beam elastic constraint improved Fourier series free vibration semi-analytical solution

Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties

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Chinese Journal of Chemical Engineering 2024年第2期66卷 19-30页

作者： Kang He Liangyu zhu Yanmei Wang CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored *** mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force *** mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon *** the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1.,and 93.5%,*** is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=1.^(-3)mol·L^(-1.for pepsin,and pH 5,I=1.^(-5)mol·L^(-1.for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=1.^(-1.mol·L^(-1.for pepsin,and pH 9,I=1.^(-1.mol·L^(-1.for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=1.^(-5)mol·L^(-1.,while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-1.^(-1.mol·L^(-1..However,alkaline protein(lysozyme,whose isoelectric point was higher than

关键词： Switchable conformation transition Controllable protein adsorption Mixed brushes Isoelectric point Antibacterial surface

Edge and lithium concentration effects on intercalation kinetics for graphite anodes

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Journal of Energy Chemistry 2024年第3期90卷 337-347,I0009页

作者： Keming zhu Denis Kramer Chao Peng School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048ShanxiChina Faculty of Mechanical Engineering Helmut-Schmidt UniversityHamburg 22043Germany School of Engineering University of SouthamptonSouthampton SO171BJUK Multiscale Crystal Materials Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina

Graphite interfaces are an important part of the anode in lithium-ion batteries(LIBs),significantly influencing Li intercalation *** anodes adopt different stacking sequences depending on the concentration of the intercalated Li *** this work,we performed first-principles calculations to comprehensively address the energetics and dynamics of Li intercalation and Li vacancy diffusion near the no n-basal edges of graphite,namely the armchair and zigzag-edges,at high Li *** find that surface effects persist in stage-Ⅱ that bind Li strongly at the edge ***,the pronounced effect previously identified at the zigzag edge of pristine graphite is reduced in LiC_(1.),penetrating only to the subsurface site,and eventually disappearing in LiC_(6).Consequently,the distinctive surface state at the zigzag edge significantly impacts and restrains the charging rate at the initial lithiation of graphite anodes,whilst diminishes with an increasing degree of *** diffusion time for Li hopping to the bulk site from either the zigzag edge or the armchair edge in LiC_(6) was observed during high state of charge due to charge *** controlling Li occupation and diffusion kinetics at this stage is also crucial for enhancing the charge rate.

关键词： Graphite anode Edge Interface Lithium-ion batteries Density functional theory

Heat Storage Performance of PCM in a Novel Vertical Pointer-Shaped Finned Latent Heat Tank

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Journal of Thermal Science 2024年第2期33卷 422-434页

作者： MAO Qianjun zhu Yuanyuan LI Tao School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China

The heat storage performance of latent heat storage systems is not good due to the poor thermal conductivity of phase change *** this paper,a new type of pointer-shaped fins combining rectangular and triangular fins has been employed to numerically simulate the melting process in the heat storage tank,and the fin geometry parameter effects on heat storage performance have been *** results indicate that compared with the bare tube and the rectangular finned tank,the melting time of the phase change material in the pointer-shaped finned tank is reduced by 64.2%and 1..1.,*** closer the tip of the triangular fin is to the hot wall,the better the heat transfer *** optimal height of the triangular fin is about 8 *** the number of fins from 4 to 6 and from 6 to 8 reduces the melting time by 1..0%and 1..7%***,increasing the number of fins from 8 to 1. only reduces the melting time by 8.4%.When the fin dimensionless length is increased from 0.3 to 0.5 and from 0.5 to 0.7,the melting time is shortened by 1..5%and 1..0%.But the melting time is only reduced by 2.9%when the dimensionless fin length is increased from 0.7 to *** optimising the design of the thermal storage system,the results can provide a reference value.

关键词： thermal energy storage phase change material pointer-shaped fins heat storage performance