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黄土区3种护坡植物三维可视化模拟与根系构型参数分析

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水土保持研究 2025年第1期32卷 218-226页

作者：张旭姚晨杜婷马志强朱宏杰汪艳杜峰中国科学院教育部水土保持与生态环境研究中心中国科学院水利部水土保持研究所中国科学院大学西北农林科技大学水土保持研究所

[目的]对植物根系数字化并进行三维实体可视化模拟，对于了解植物根系形态和为水保工程制图提供植物实物图库都具有重要的理论与实践意义。[方法]逐层挖掘黄土区酸枣、沙棘、狼牙刺3种护坡植物根系，使用3D数字化仪FasTrak获取根系三维... 详细信息

[目的]对植物根系数字化并进行三维实体可视化模拟，对于了解植物根系形态和为水保工程制图提供植物实物图库都具有重要的理论与实践意义。[方法]逐层挖掘黄土区酸枣、沙棘、狼牙刺3种护坡植物根系，使用3D数字化仪FasTrak获取根系三维点阵坐标后利用SketchUp软件对根系进行三维建模并提取根系构型参数。为了建立完整的植物地上地下三维实体图库，同时使用FreeScan UE激光扫描仪得到相应地上部点云数据，经Soildworks软件渲染后建立植物地上部三维模型。[结果](1)建立了3种植物的地上地下三维实体模型图；(2)3种植物的根幅/根深均大于1(1.10～3.41),根系在水平方向上占有优势，狼牙刺最小为1.10;(3)3种植物冠幅/根幅分别为酸枣(0.25)、沙棘(0.69)、狼牙刺(0.73),均小于1,植物根系较地上部在水平方向上占优；(4)3种植物Fitter拓扑指数均接近于1,分别为酸枣(0.915)、沙棘(0.802)、狼牙刺(0.771),接近于鱼尾型分支；(5)植物根系总根长、总表面积、总体积在上坡方向占比大于50%,均在上坡方向更有优势。[结论]所建立的植物三维模型图对植物还原度高，为整株植物三维可视化模拟提供了一种方法。

关键词：黄土区整株植物三维可视化模拟 SketchUp 根系形态

Predicting protein subchloroplast locations:the 10th anniversary

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Frontiers of Computer Science 2021年第2期15卷 1-11页

作者： Jian SUN Pu-feng du College of Intelligence and Computing Tianjin UniversityTianjin300350China

Chloroplast is a type of subcellular organelle in green plants and *** is the main subcellular organelle for conducting photosynthetic *** proteins,which localize within the chloroplast,are responsible for the photosynthetic process at molecular *** chloroplast can be further divided into several *** in different compartments are related to different steps in the photosynthetic *** the molecular function of a protein is highly correlated to the exact cellular localization,pinpointing the subchloroplast location of a chloroplast protein is an important step towards the understanding of its role in the photosynthetic *** process for determining protein subchloroplast location is always costly and time ***,computational approaches were developed to predict the protein subchloroplast locations from the primary *** the last decades,more than a dozen studies have tried to predict protein subchloroplast locations with machine learning *** sequence features and various machine learning algorithms have been introduced in this research *** this review,we collected the comprehensive information of all existing studies regarding the prediction of protein subchloroplast *** compare these studies in the aspects of benchmarking datasets,sequence features,machine learning algorithms,predictive performances,and the implementation *** summarized the progress and current status in this special research *** also try to figure out the most possible future works in predicting protein subchloroplast *** hope this review not only list all existing works,but also serve the readers as a useful resource for quickly grasping the big picture of this research *** also hope this review work can be a starting point of future methodology studies regarding the prediction of protein subchloroplast locations.

关键词： subchloroplast locations sequence features performance measures online services machine learning

How ploughing and frictional melting regulate ice-skating friction

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Friction 2023年第11期11卷 2036-2058页

作者： feng du Peng KE Ping HONG School of Transportation Science and Engineering Beihang UniversityBeijing 100191China Beijing Sports University Beijing 100084China

The slipperiness of ice is well known while,for ice skating,its mechanism still needs further investigation,where the complex interactions including the thermal conduction of the skate–meltwater–ice system,the ploughing and the frictional melting of ice to the friction force are still *** study presents a theoretical framework and a simplified analytical solution to unveil the friction mechanism when a curved skate sliding on *** theory is validated by experiments and the effects of these various factors,including the sliding velocity,the ice temperature,the supporting weight,and the geometry of the skate blade to the friction are revealed in *** study finds that the contribution of friction force from the ploughing deformation through skate indentation and that from the fluid friction through the shear motion of the meltwater layer is comparable with each other,which thus clarifies how the ploughing deformation of the ice substrate together with its frictional melting regulates the friction during skating.

关键词： ice friction skating ploughing frictional melting coefficient of friction

Reilly-type inequalities for p-Laplacian on compact Riemannian manifolds

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Frontiers of Mathematics in China 2015年第3期10卷 583-594页

作者： feng du Jing MAO School of Mathematics and Physics Science Jingchu University of Technology Jingmen 448000 China Department of Mathematics Harbin Institute of Technology (Weihai) Weihai 264209 China

For a compact Riemannian manifold M immersed into a higher dimensional manifold which can be chosen to be a Euclidean space, a unit sphere, or even a projective space, we successfully give several upper bounds in terms of the norm of the mean curvature vector of M for the first non-zero eigenvalue of the p-Laplacian （1 〈 p 〈＋∞） on M. This result can be seen as an extension of Reilly＇s bound for the first non-zero closed eigenvalue of the Laplace operator.

关键词： p-Laplacian eigenvalue mean curvature vector

EXPERIMENTAL INVESTIGATION FOR THE EFFECT OF ROTATION ON THREE-DIMENSIONAL FLOW FIELD IN FILM-COOLED TURBINE

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Chinese Journal of Mechanical Engineering 2007年第1期20卷 10-15页

作者： YUAN feng ZHU Xiaocheng du Zhaohui School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

An experimental investigation of three-dimensional flow field in a film-cooled turbine model is carried out by using particle image velocimeter （PIV） in a low-speed wind tunnel. The effects of different blowing ratios （M=1.5, 2） on the flow field are studied. The experimental results reveal the classical phenomena of the formation of kidney vortex pair and secondary flow in wake region behind the jet hole. And the changes of the kidney vortex pair and the wake at different locations away from the hole on the suction and pressure sides are also studied. Compared with the flow field in stationary cascade, there are centrifugal force and Coriolis force existing in the flow field of rotating turbine, and these forces bring the radial velocity in the jet flow. The effect of rotatien on the flow field of the pressure side is more distinct than that on the suction side from the measured flow fields in Y-Z plane and radial velocity contours. The increase of blowing ratio makes the kidney vortex pair and the secondary flow in the wake region stronger and makes the range of the wake region enlarged.

关键词： Film-cooled turbine rotor PIV measurement Blowing ratio Three-dimensional flow field

An Iterative Rounding 2-approximation Algorithm for the k-partial Vertex Cover Problem

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Acta Mathematicae Applicatae Sinica 2014年第2期30卷 271-278页

作者： Jian-hua TU Jun-feng du feng-mei YANG School of Science Beijing University of Chemical Technology

We study a generalization of the vertex cover problem. For a given graph with weights on the vertices and an integer k, we aim to find a subset of the vertices with minimum total weight, so that at least k edges in the graph are covered. The problem is called the k-partial vertex cover problem. There are some 2-approximation algorithms for the problem. In the paper we do not improve on the approximation ratios of the previous algorithms, but we derive an iterative rounding algorithm. We present our technique in two algorithms. The first is an iterative rounding algorithm and gives a （2 ＋ Q/OPT ）-approximation for the k-partial vertex cover problem where Q is the largest finite weight in the problem definition and OPT is the optimal value for the instance. The second algorithm uses the first as a subroutine and achieves an approximation ratio of 2.

关键词： approximation algorithm iterative rounding k-partial vertex cover combinatorial optimization

Graphene-supported bimetal phosphorus trisulfides as novel 0D–2D nanohybrid for high rate Li-ion storage

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Journal of Energy Chemistry 2018年第1期27卷 190-194页

作者： Cheng-feng du Qinghua Liang Qingyu Yan School of Materials Science and Engineering Nanyang Technological University

Herein, we report on the synthesis and Li-ion storage properties of the 0D–2D nanohybrid consisted of bimetal phosphorus trisulfides nanoneedles（Co_（0.5）Ni_（0.5）PS_3） and graphene nanosheets（denoted as Co_（0.5）Ni_（0.5）PS_3@G）. By choosing the Co_（0.5）Ni_（0.5）（OH）_2 nanoneedles as precursor, the Co_（0.5）Ni_（0.5）PS_3 derived by a simple solid-state transformation（SST） process was successfully attached onto the graphene *** as-prepared nanohybrids showed a superior cycling stability and rate performance for Li-ion *** cycling at a current density of 0.5 A g^（-1） for 500 cycles, the capacity are 456 mAh g^（-1）. Particularly,the capacity can reach 302 mAh g^（-1） at a current density of 10 A g^（-1）, which is 66.2% of the capacity at0.5 A g^（-1）. Even cycling at a current density of 50 A g^（-1）, the nanocomposite can still kept a capacity of 153 mAh g^（-1） with a capacity retention of 33.6%.

关键词： Metal phosphorus trisulfides Nanohybrid GrapheneLi-ion storage

Preparation of a biomimetic superomniphobic hierarchical structure and analysis of droplet wettability

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Biosurface and Biotribology 2022年第2期8卷 129-139页

作者： Jing Li Qunxiang feng Nan Guo Fei Wang Xin du feng du College of Mechanical and Electric Engineering Changchun University of Science and TechnologyChangchunChina School of Opto-Electronic Engineering Changchun University of Science and TechnologyChangchunChina Non-Commissioned Officer School of Army Academy of Armored Forces Changchun Economic and Technological Development Zone of Jilin ProvinceChangchunChina

In this study,a bioinspired hierarchical structure was formed with superomniphobicity on a 7075 aluminium alloy using laser *** morphology and wetting characteristics of the biomimetic sample surface were characterised using scanning electron microscopy,laser confocal microscopy,and contact angle *** effect of the liquid properties and surface structures on the rolling behaviour was *** results suggest that the fabricated biomimetic sample surface was a hierarchical *** prepared sample had superomniphobicity and low adhesion properties,and the contact angles of six different liquid droplets on the sample surface reached or approached 150°.Specifically,the largest contact angle was 152°,and the average rolling angle was 7.7°.This multi-hydrophobic surface provides a valuable reference for the research study and use of a variety of solid–liquid contacts.

关键词： bioinspiration hierarchical structures low adhesion superomniphobicity

Tuning the reversible chemisorption of hydroxyl ions to promote the electrocatalysis on ultrathin metal-organic framework nanosheets

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Journal of Energy Chemistry 2022年第2期31卷 71-77页

作者： Hong Yu Yao Jing Cheng-feng du Jiong Wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072ShaanxiChina Institute of Advanced Synthesis Northwestern Polytechnical UniversityXi’an 710072ShaanxiChina

Interfacial engineering to alter the configuration of active sites in heterogeneous catalysts is a potential strategy for activity enhancement,but it remains unelucidated for metal-organic frameworks(MOFs).Here,we demonstrate that the surface of two-dimensional Co-based MOF is modified by decorating Ag quantum dots(QDs)simply through in-situ reduction of Ag+*** oxygen evolution reaction(OER),it reveals that the catalysis is mediated by the reversible redox of Co sites between Co^(3+) and Co^(4+) states coupling with transfer of OH*** decoration of Ag QDs decreases the redox potential of Co sites,and thus effectively decreases the overpotential of *** TOFs of Co sites are increased by 77 times to reach 5.4 s^(-1) at an overpotential of 0.35 *** attribute the activity enhancement to the tuning of the coupling process between Co sites and OHions during the redox of Co sites by Ag QDs decoration based on Pourbaix analysis.

关键词： 2D metal-organic frameworks Interfacial engineering Pourbaix analysis Chemisorption of hydroxyl ions Oxygen evolution reaction