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食用蔬菜能吸收和积累微塑料 期刊论文 OAI收割
科学通报, 2019, 卷号: 64, 期号: 9, 页码: 928-934
作者: 李连祯; 周倩; 尹娜; 涂晨; 骆永明

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收藏 | 浏览/下载：145/0 | 提交时间：2020/06/17

微塑料生菜聚苯乙烯微球吸收积累健康风险 microplastics lettuce polystyrene microbeads uptake accumulation human health risk Microplastic (MP, 100 nm-5 mm) may present an attributable risk to ecosystem and human health, and its pollution has become a global environmental concern. Despite a wealth of information on the accumulation of MPs in aquatic species, there is no information on the uptake and accumulation of MPs by higher plants. Terrestrial edible plants are directly exposed to MPs when agricultural soil was applied with organic manure, sewage sludge as fertilizer or plastic mulching. In this paper, the uptake of two sizes of polystyrene (PS) microbeads (0.2 and 1.0 mum) and then their distribution and migration in an edible plant lettuce were firstly investigated based on laboratory experiments. We used fluorescent markers to track PS microbeads in plant tissues and found fluorescence to be a sensitive and reliable detection method. Sections from untreated control lettuce showed no autofluorescence. When roots were treated with fluorescently labeled PS microbeads, the microbeads could be identified by its fluorescence. Our main study investigated the uptake of 0.2 mum beads, as few luminescence signals were observed in lettuce roots for 1.0 mum beads in our experiment. We observed that 0.2 mum fluorescent microbeads were extracellularly trapped in the root cap mucilage (which is a highly hydrated polysaccharide) and a dark green tip (which was typical of lettuce roots exposed to label PS beads) was usually visible to the naked eye. Confocal images revealed that the PS luminescence signals were mainly located in the vascular system and on the cell walls of the cortex tissue of the roots, indicated that the beads passed through the intercellular space via the apoplastic transport system. Once inside the central cylinder, the 0.2 mum PS beads were transferred from the roots to the stems and leaves via the vascular system following the transpiration stream. We also observed that the PS beads adhered to one another and self-assembled systematically into grape-like and (chain) string-like clusters in the intercellular space of the root and stem vascular tissue of lettuce plant. In contrast to the root and stem, PS beads were dispersed in the leaf tissue. Here, for the first time we provide evidence of the adherence, uptake, accumulation, and translocation of submicrometer MPs within an edible plant. Our findings highlight the previously underappreciated human exposure pathway to MPs through the consumption of contaminated crops and emphasize the need for new management strategies to control the release of MPs waste products into the terrestrial environment. Ultimately, the potential impacts of low range sized MPs on food safety of crop plants and human health need to be urgently considered.

The global solution and nonlinear stability for the coupled CGL-Burgers equations for sequential flames in R-N 期刊论文 OAI收割
ANALYSIS AND APPLICATIONS, 2017, 卷号: 15, 期号: 4, 页码: 477-504
作者: Wu, Xinglong; Guo, Boling

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收藏 | 浏览/下载：28/0 | 提交时间：2017/12/06

The Coupled Cgl-burgers Equations Sequential Flames Global Solution Besov Spaces Bony Decomposition Nonlinear Stability And inStability Plane Wave Linearized Method

A global procedure for stability analysis of slopes based on the Morgenstern-Price assumption and its applications 期刊论文 OAI收割
COMPUTERS AND GEOTECHNICS, 2016, 卷号: 80, 页码: 97-106
作者: Jiang, Wei; Zheng, Hong; Sun, Guanhua; Cheng, Shengguo

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收藏 | 浏览/下载：58/0 | 提交时间：2018/06/05

Landslide Limit equilibrium methods Slope Methods of slices The global method

A shape context based Hausdorff similarity measure in image matching 会议论文 OAI收割
5th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Infrared Imaging and Applications, Beijing, June 25-27, 2013
作者: Ma TL(马天磊); Liu YP(刘云鹏); Shi ZL(史泽林); Yin J(尹健)

收藏 | 浏览/下载：37/0 | 提交时间：2013/12/26

The traditional Hausdorff measure, which uses Euclidean distance metric (L2 norm) to define the distance between coordinates of any two points, has poor performance in the presence of the rotation and scale change although it is robust to the noise and occlusion. To address the problem, we define a novel similarity function including two parts in this paper. The first part is Hausdorff distance between shapes which is calculated by exploiting shape context that is rotation and scale invariant as the distance metric. The second part is the cost of matching between centroids. Unlike the traditional method, we use the centroid as reference point to obtain its shape context that embodies global information of the shape. Experiment results demonstrate that the function value between shapes is rotation and scale invariant and the matching accuracy of our algorithm is higher than that of previously proposed algorithm on the MEPG-7 database.

Retrieval of snow depth in Northeast China using FY-3B/MWRI passive microwave remote sensing data (EI CONFERENCE) 会议论文 OAI收割
Satellite Data Compression, Communications, and Processing VIII, August 12, 2012 - August 13, 2012, San Diego, CA, United states
Ren R.; Gu L.; Chen H.; Cao J.

收藏 | 浏览/下载：138/0 | 提交时间：2013/03/25

Comparing with optical remote sensing techniques passive remote sensing data have been proved to be effective for observing snowpack parameters such as snow depth and snow water equivalent which can penetrate snowpack without clouds interferences. The Microwave Radiation Imager (MWRI) loaded on the Chinese FengYun-3B (FY-3B) satellite is gradually used in the global environment research through November 2011. In this paper we proposed a snow depth retrieval algorithm to estimate snow depth in Northeast China using MWRI passive microwave remote sensing data. A decision tree method of snow identification was firstly designed to distinguish different snow cover conditions in order to eliminate other interference signals. After using the proposed decision tree method the processing results were further used to retrieve the snow depth in Northeast China. Finally the practical snow depth data and the MODIS data were collected for the accuracy assessment of the proposed snow depth retrieval method. The experimental results demonstrated that the RMSE of snow depth used the proposed method was approximately 3 cm in Northeast China. 2012 SPIE.

Parameter optimization of passive dynamic walking biped with knees (EI CONFERENCE) 会议论文 OAI收割
2012 2nd International Conference on Materials Science and Information Technology, MSIT 2012, August 24, 2012 - August 26, 2012, Xi'an, Shaan, China
作者: Zhang P.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

A method to find the optimized parameter values of passive dynamic walking biped is presented. The effects of biped physical parameters on the stability property of passive gaits are studied by simulation experiments. The chosen parameters include the mass distribution length of leg and slope angle. The stability property of passive walking limit cycles is used as criterion of optimization calculation including the orbital stability described by eigen-values of linearized Poincare map and the global property described by size of attraction region. The simulation results show how the stability of limit cycle varies when physical parameters of the passive biped change. The work is useful to explore the inherent property of passive dynamic walking and can be used as an important instruction in the mechanical design of biped robots based on principle of passive dynamic walking. (2012) Trans Tech Publications Switzerland.

Classification of hyperspectral image based on SVM optimized by a new particle swarm optimization (EI CONFERENCE) 会议论文 OAI收割
2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2012, June 1, 2012 - June 3, 2012, Nanjing, China
作者: Gao X.; Yu P.; Yu P.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

Support Vector Machine (SVM) is used to classify hyperspectral remote sensing image in this paper. Radial Basis Function (RBF) which is most widely used is chosen as the kernel function of SVM. Selection of kernel function parameter is a pivotal factor which influences the performance of SVM. For this reason Particle Swarm Optimization (PSO) is provided to get a better result. In order to improve the optimization efficiency of kernel function parameter firstly larger steps of grid search method is used to find the appropriate rang of parameter. Since the PSO tends to be trapped into local optimal solutions a weight and mutation particle swam optimization algorithm was proposed in which the weight dynamically changes with a liner rule and the global best particle mutates per iteration to optimize the parameters of RBF-SVM. At last a 220-bands hyperspectral remote sensing image of AVIRIS is taken as an experiment which demonstrates that the method this paper proposed is an effective way to search the SVM parameters and is available in improving the performance of SVM classifiers. 2012 IEEE.

Image matching using a bat algorithm with mutation (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Mechatronic Systems and Automation Systems, MSAS 2012, July 21, 2012 - July 21, 2012, Wuhan, China
作者: Zhang J.; Wang G.; Zhang J.; Zhang J.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

Due to shortcoming of traditional image matching for computing the fitness for every pixel in the searching space a new bat algorithm with mutation (BAM) is proposed to solve image matching problem and a modification is applied to mutate between bats during the process of the new solutions updating. This new approach can accelerate the global convergence speed while preserving the strong robustness of the basic BA. The realization procedure for this improved meta-heuristic approach BAM is also presented. To prove the performance of this proposed meta-heuristic method BAM is compared with BA and other population-based optimization methods DE and SGA. The experiment shows that the proposed approach is more effective and feasible in image matching than the other model. (2012) Trans Tech Publications Switzerland.

The movement estimation of target and background by fourier phase spectrum difference (EI CONFERENCE) 会议论文 OAI收割
2010 6th International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2010, September 23, 2010 - September 25, 2010, Chengdu, China
作者: Zhang X.; Zhang X.; Zhang X.; Wang J.; Zhang S.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

An algorithm for estimating displacement of the moving target and background by shift theory of Fourier transform is presented. According to the relation between the change and the Fourier transform of image sequence the method employs the displacement value of the moving target and background by the difference of Fourier phase spectrum. The algorithm estimates the movements from the whole field of the image with excellent global property. This paper provides the calculus and experiments of the algorithm which show the accuracy of 1 pixel. 2010 IEEE.

Environment modeling of AS-R robot based on BP Neural Network (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
Xie M.-J.; Yu X.-L.; Wang Z.-Q.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

There are some limitations when environment model of AS-R mobile robot is obtained by only using a separate CCD camera or ultrasonic sensor array. The BP neural network is designed to fuse information of the two sensors to obtain the robot's environment model in this paper. The input of BP neural network is the intercept and slope of the edge line obtained CCD camera and ultrasonic sensor arrays which is processed by through the global coordinates of coordinate transformation. The output of BP network is the fused intercept and slope of the straight edge. Experiment shows that environment model is feasible for the AS-R mobile robot and the environment modeling method has more reliability and accuracy. 2010 IEEE.