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Ecological vulnerability assessment of the Ya'an-Qamdo section along the southern route of the Sichuan-Tibet transportation corridor

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Journal of Mountain Science 2022年第8期19卷 2202-2213页

作者： BAO Fang qiu jian School of Architecture Southwest Jiaotong UniversityChengdu 611756China China Railway Eryuan Engineering Group Co. Ltd.Chengdu 610031China

Identifying the ecological vulnerability of the sensitive and fragile ecosystem of the Ya’anQamdo section along the southern route of the Sichuan-Tibet transport corridor is of paramount importance to reduce environmental damage resulting from infrastructure *** paper divided the Ya’an-Qamdo transport section into 22subzones according to their ecological environment *** on the vulnerability evaluation model established by the fuzzy matter-element analysis method,the eight main assessment indicators of ecological vulnerability were windstorm,rainstorm,snowstorm,extreme temperature,extreme air pressure,geological hazard,natural conditions,and social *** rating and ranking of vulnerability in each subzone were based on the weight of the judgment *** processes were used to verify the rationality of both the indicators themselves and their *** results of this study show that subzone 9,located in the subalpine cold and humid forest and scrubland zone,is the most vulnerable,and subzone 1,located in the low-to mid-land warm and humid forest zone,is the least *** conclusion of the study suggests that targeted measures of ecological protection should be formulated before development and construction of major transportation *** should evade the most vulnerable areas,and in-depth research on ecological restoration should be carried out in low-to midvulnerability areas so that the ecological environment along the route can be protected effectively for sustainable economic and social development.

关键词： Ecosystem Vulnerability Subzone Sichuan-Tibet transportation corridor

Internal structural optimization of hollow fan blade based on sequential quadratic programming algorithm

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航空动力学报 2011年第4期26卷 787-793页

作者： YANG jian-qiu WANG Yan-rong School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

Several structural design parameters for the description of the geometric features of a hollow fan blade were determined.A structural design optimization model of a hollow fan blade which based on the strength constraint and minimum mass was established based on the finite element method through these ***,the sequential quadratic programming algorithm was employed to search the optimal *** groups of value for initial design variables were chosen,for the purpose of not only finding much more local optimal results but also analyzing which discipline that the variables according to could be benefit for the convergence and *** surface method and Monte Carlo simulations were used to analyze whether the objective function and constraint function are sensitive to the variation of variables or *** the robust results could be found among a group of different local optimal solutions.

关键词： hollow fan blade structural optimization sequential quadratic algorithm finite element method Monte Carlo simulations

Automated Kinematics Measurement and Aerodynamics of a Bioinspired Flapping Rotary Wing

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Journal of Bionic Engineering 2017年第4期14卷 726-737页

作者： jianghao Wu jian qiu Yanlai Zhang School of Transportation Science and Engineering Beihang University Beijing 1 O0191 China

A physical model for a micro air vehicle with Flapping Rotary Wings （FRW） is investigated by measuring the wing kine- matics in trim conditions and computing the corresponding aerodynamic force using computational fluid dynamics. In order to capture the motion image and reconstruct the positions and orientations of the wing, the photogrammetric method is adopted and a method for automated recognition of the marked points is developed. The characteristics of the realistic wing kinematics are presented. The results show that the non-dimensional rotating speed is a linear function of non-dimensional flapping frequency regardless of the initial angles of attack. Moreover, the effects of wing kinematics on aerodynamic force production and the underlying mechanism are analyzed. The results show that the wing passive pitching caused by elastic deformation can sig- nificantly enhance lift production. The Strouhal number of the FRW is much higher than that of general flapping wings, indi- cating the stronger unsteadiness of flows in FRW.

关键词： bioinspired flapping rotary wing aerodynamics wing kinematics measurement computational fluid dynamics micro air vehicle

Microscopic experimental and numerical research on rejuvenators: A review

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 180-207页

作者： Zhiyu Han Peiliang Cong jian qiu Engineering Research Center of Transportation Materials Ministry of EducationSchool of Materials Science and EngineeringChang’an UniversityXi'an 710064China Asfalt Nu C.V. Culemborg 4100 ADthe Netherlands

Prompting high content of reclaimed asphalt pavement(RAP) to be used in road building and maintenance has drawn great attention. The application of rejuvenators is an efficient way to ensure the performance of recycled asphalt mixtures. However, as various types of rejuvenators emerging, limited understanding about rejuvenation poses challenges to put effective ones into use. For precisely evaluating the performance of rejuvenators, plenty of studies were conducted to ascertain the fundamental mechanism of rejuvenating from the microscopic view. This paper provides an overview of studies focusing on the change inside asphalt after adding rejuvenators. Chemical compositions of rejuvenators were collected as basic information. Both laboratorial experiments and molecular dynamic simulations were investigated to not only compare the effectiveness of several rejuvenators but also explain the rejuvenating mechanism. Finally, functional groups of rejuvenator structures were comprehensively examined to provide global understanding about how chemical compositions influence the efficacy of rejuvenators. This review highlights that the essential capacity of a true rejuvenator is to disturb asphaltene agglomerations. Besides, the molecular structures of rejuvenators will not only affect their deagglomerating abilities but also the performances of diffusion and durability. It has been found that gel-permeation chromatography(GPC) analysis is effective in evaluating the performance of rejuvenators, while Fourier transform infrared spectroscopy(FT-IR) and SARA(saturates, aromatics, resins and asphaltenes) analysis are only suitable for assessing asphalt oxidization. In addition, comparing some tests can only detect changes, molecular dynamic simulation can reveal the mechanism both of data and vision. The results of this work can provide comprehensive knowledge for the evaluation and development of rejuvenators.

关键词： Road engineering Rejuvenator Deagglomeration Molecular simulation GPC

Neighbor Sum Distinguishing Index of Sparse Graphs

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Acta Mathematica Sinica,English Series 2020年第6期36卷 673-690页

作者： Ji Hui WANG Bao jian qiu jian Sheng CAI School of Mathematical Sciences University of JinanJinan 250022P.R.China School of Mathematics and Information Sciences Weifang UniversityWeifang 261061P.R.China

A proper k-edge coloring of a graph G is an assignment of one of k colors to each edge of G such that there are no two edges with the same color incident to a common *** f(v)denote the sum of colors of the edges incident to v.A k-neighbor sum distinguishing edge coloring of G is a proper k-edge coloring of G such that for each edge uv∈E(G),f(u)≠f(v).Byχ’_∑(G),we denote the smallest value k in such a coloring of *** mad(G)denote the maximum average degree of a graph *** this paper,we prove that every normal graph with mad(G)<10/3 andΔ(G)≥8 admits a(Δ(G)+2)-neighbor sum distinguishing edge *** approach is based on the Combinatorial Nullstellensatz and discharging method.

关键词： Proper edge coloring neighbor sum distinguishing edge coloring maximum average degree Combinatorial Nullstellensatz

A Polynomial Prediction Filter Method for Estimating Multisensor Dynamically Varying Biases

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Chinese Journal of Aeronautics 2007年第3期20卷 240-246页

作者： GAO Yu ZHANG jian-qiu HU Bo Department of Electronics Fudan University Shanghai 200433 China

The estimation of the sensor measurement biases in a multisensor system is vital for the sensor data fusion. A solution is provided for the estimation of dynamically varying multiple sensor biases without any knowledge of the dynamic bias model parameters. It is shown that the sensor bias pseudomeasurement can be dynamically obtained via a parity vector. This is accomplished by multiplying the sensor uncalibrated measurement equations by a projection matrix so that the measured variable is eliminated from the equations. Once the state equations of the dynamically varying sensor biases are modeled by a polynomial prediction filter, the dynamically varying multisensor biases can be obtained by Kalman filter. Simulation results validate that the proposed method can estimate the constant biases and dynamic biases of multisensors and outperforms the methods reported in literature.

关键词： signal processing dynamic bias estimation simulation multisensor Kalman filter

Suppression of Rayleigh-Taylor instability by gyroviscosity and sheared axial flow in imploding plasma pinches

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核聚变与等离子体物理 2007年第2期27卷 87-94页

作者： HUANG Lin jian Guang-de qiu Xiao-ming Southwestern In stitute of Physics Chengdu 610041

The synergistic stabilizing effect of gyroviscosity and sheared axial flow on the Rayleigh-Taylor instability in Z-pinch implosions is studied by means of the incompressible viscid magneto-hydrodynamic *** gyroviscosity(or finite Larmor radius) effects are introduced in the momentum equation through an anisotropic ion stress *** relation with the effect of a density discontinuity is *** results indicate that the short-wavelength modes of the Rayleigh-Taylor instability are easily stabilized by the gyroviscosity *** long wavelength modes are stabilized by the sufficient sheared axial ***,the synergistic effects of the finite Larmor radius and sheared axial flow can heavily mitigate the Rayleigh-Taylor *** synergistic effect can compress the Rayleigh-Taylor instability to a narrow wave number *** with a sufficient gyroviscosity and large enough flow velocity,the synergistic effect can completely suppressed the Rayleigh-Taylor instability in whole wave number region.

关键词：雷利-泰勒不稳定性回转粘性内向爆炸等离子体箍缩增敏作用有限拉莫尔旋进半径增长比率

Linking soil organic carbon mineralization to soil physicochemical properties and bacterial alpha diversity at different depths following land use changes

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Ecological Processes 2023年第1期12卷 545-559页

作者： Jing Guo Wulai Xiong jian qiu Guibin Wang Co-Innovation Center for Sustainable Forestry in Southern China College of ForestryNanjing Forestry University159 Longpan RoadNanjing 210037China

Background Anthropogenic land use changes(LUCs)impart intensifying impacts on soil organic carbon(SOC)turnover,leading to uncertainty concerning SOC mineralization patterns and determining whether soils act as“source”or“sink”in the global carbon ***,understanding the SOC mineralization characteristics of different LUC patterns and their potential influencing factors is *** indoor incubation experiment was conducted to study the SOC mineralization patterns and their relevance to soil physicochemical properties,soil enzyme activity,SOC fractions,and bacterial alpha *** soils were collected from two layers of five typical LUC patterns in Yellow Sea Forest Park,including four that were converted from wheat-corn rotation systems[a gingko plantation(G),a metasequoia plantation(M),a gingko-wheat-corn agroforestry system(GW),and a gingko-metasequoia system(GM)]and a traditional wheat-corn system(W).Results LUCs had significant and diverse impacts on the SOC content and SOC fraction contents and on soil enzyme *** cumulative SOC mineralization was significantly higher in the M systen than in the W and GW systems at 0-20 cm depth and higher in the G system than in the GW system at 20-40 cm depth after 60-day *** mineralization ratio was highest in the W system and lowest in the GW *** soil pH and bulk density had a significant negative correlation with the cumulative SOC mineralization,while the soil bacterial Shannon index had a significant positive correlation with cumulative SOC *** stepwise linear regression analysis showed that the SOC mineralization potential was dominantly explained by the bacterial Shannon index and operational taxonomic units(OTUs).The GW system had lower potentially mineralizable SOC and higher SOC ***,the incubation time and cumulative SOC mineralization were well fitted by the first-order kinetic *** LUCs significantly changed SOC miner

关键词： Land use change Indoor incubation Soil organic carbon mineralization Soil enzyme activity Bacterial alpha diversity

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Neuronomodulation of Excitable Neurons

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Neuroscience Bulletin 2024年第1期40卷 103-112页

作者： Yizhang Chen Lin Xiao jian qiu Institute of Neuroscience Second Military Medical UniversityShanghai 200433China Institute for Brain Research and Rehabilitation Key Laboratory of BrainCognition and Education Sciences of Ministry of EducationSouth China Normal UniversityGuangzhou 510631China Department of Chemical Physiology and Biochemistry Oregon Health and Science UniversityPortlandOR 97239USA

Neuronomodulation refers to the modulation of neural conduction and synaptic transmission(i.e.,the conduction process involved in synaptic transmission)of excitable neurons via changes in the membrane potential in response to chemical substances,from spillover neuro-transmitters to paracrine or endocrine hormones circulating in the *** can be direct or indirect,depending on the transduction pathways from the ligand binding site to the ion pore,either on the same molecule,*** ion channel,or through an intermediate step on different *** major players in direct neurono-modulation are ligand-gated or voltage-gated ion *** key process of direct neuronomodulation is the binding and chemoactivation of ligand-gated or voltage-gated ion channels,either orthosterically or allosterically,by various *** neuronomodulation involves metabotropic receptor-mediated slow potentials,where steroid hormones,cytokines,and chemokines can implement these *** neuronomodulation is of great significance for understanding the physiological mechanisms of brain function,and the occurrence and treatment of diseases.

关键词： Neuron Membrane potential Excitability Chemoactivation Neuronomodulation