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| 1 | Prediction of nitrogen and phosphorus contents in citrus leaves based on hyperspectral imaging显示文摘The nutritional status of citrus leaves is very important to the determining of fertilization plans.The spectrum technique is a quick,un-injured method and is becoming widely used for plant nutrient estimation.The possibility and method of using spectrum technique to estimate the nutrient of citrus leaf was explored in this study.A total amount of 135 leaves from the mature spring shoots of navel orange trees(C.sinensis Osbeck,“Newhall”)were collected and randomly grouped into two sets of samples:100 leaves for the calibration set and 35 leaves for the prediction set.The hyperspectral images were scanned upper and lower side of each leaf and then the total nitrogen(N)and phosphorus(P)contents of each leaf were measured.The raw spectra data were extracted to generate average spectra curves,preprocessed with five different methods,and was used to build N and P content prediction models.The performances of the five preprocessing methods,i.e.,Savitzky-Golay smoothing(SGS),standard normal variate(SNV),multiplicative scatter correction(MSC),first-derivative(1-Der)and second-derivative(2-Der),were tested with linear partial least squares(PLS)models and nonlinear least squares-support vector machine(LS-SVM)models.The results showed that the SG-PLS and PLS were the best for the N predicting(Rp=0.9049,RMSEP=0.1041)and P(Rp=0.9235,RMSEP=0.0514)in citrus leaves,respectively;the hyperspectral image data from leaf‟s upper side predicting better for the contents of N and P.The study suggested that the hyperspectral image data from the upper side of the citrus leaves are suitable for nondestructive estimation of nutrient content. | Liu Yanli Lyu Qiang He Shaolan Yi Shilai Liu Xuefeng Xie Rangjin Zheng Yongqiang Deng Lie | 2015 | International Journal of Agricultural and Biological Engineering2015，8，2： | 5 |
| 2 | Estimation of carbon and nitrogen contents in citrus canopy by low-altitude remote sensing显示文摘The study aimed to investigate the fast and nondestructive method for detecting carbon and nitrogen content in citrus canopy.The multispectral imagery of Tarocco blood orange(Citrus sinensis L.Osbeck)plant canopy was obtained by a multispectral camera array mounted at an eight-rotor unmanned aerial vehicle(UAV)flying at an altitude of 100 m above the canopy in Wanzhou District of Chongqing Municipality,China.Average spectral reflectance data of the whole canopy,mature leaf areas and young leaves areas were extracted from the imagery.Two spectral pre-processing methods,multiplicative scatter correction(MSC)and standard normal variable(SNV),and two modeling methods,the partial least squares(PLS)and the least squares support vector machine(LS-SVM),were adopted and compared for their prediction accuracy of total content of nitrogen,soluble sugar and starch in the leaves.The results showed that,based on the spectral data extracted from the mature leaves in the multispectral imagery,the PLS model based on the original spectrum obtained a Rp(correlation coefficient)of 0.6469 and RMSEP(root mean squares error of prediction)of 0.1296,suggested that it was the best for the prediction of total nitrogen content;the PLS model based on MSC(multiplicative scatter correction)spectrum pre-processing was the best for predicting total soluble sugar content(Rp=0.6398 and RMSEP=8.8891);and the LS-SVM model based on MSC was the best for the starch content prediction(Rp=0.6822 and RMSEP=14.9303).The prediction accuracy for carbon and nitrogen contents based on the spectral data extracted from the whole canopy and the young leaves were lower than that from the mature leaves.The results indicate that it is feasible to estimate the carbon and nitrogen contents by low-altitude airborne multispectral images. | Liu Xuefeng Lyu Qiang He Shaolan Yi Shilai Hu Deyu Wang Zhitao Xie Rangjin Zheng Yongqiang Deng Lie | 2016 | International Journal of Agricultural and Biological Engineering2016，9，5： | 2 |
| 3 | Pd/TiO2 Nanospheres with Three-dimensional Hyperstructure for Enhanced Photodegradation of Organic Dye显示文摘Pd/TiO2 nanospheres assembled from nanorods with three-dimensional hyperstructure for enlianced photodegradation of organic dye was prepared by a sample solvothemial method. Further, it was used for degradation of methyl orange(MO) under the illumination of visible-light(simulated).The results show that Pd/TiO2 with 2%(mass fraction) Pd exhibits the noticeable activity in photodegrading of MO.The detailed analysis shows that this enhancement is attributed to the reduction of the rate of electron-hole recombination and surface plasmon resonance of Pd. The high activity and good stability of the obtained Pd/TiO2 nano spheres make it a promising photocatalyst for solving the environmental pollution problems. | WANG Huan XIAO Liguang WANG Chao LIN Bin LYU Sa CHU Xuefeng CHI Yaodan YANG Xiaotian WANG Xinyan | 2019 | Chemical Research in Chinese Universities2019，35，4： | 1 |
| 4 | Experimental,analytical and numerical investigation on tensile behavior of twisted fiber yarns显示文摘Stitched composite materials are emerging as a promising material due to their high interlaminar strength,combined performance and light weight.The mechanical properties of stitch yarns are very essential for stitched composite structures.In this study,the tensile behaviors of the twisted fiber yarn in stitched composites were investigated experimentally,analytically and numerically.Two kinds of cross-sectional area of twisted yarn are proposed and discussed.The paper presents an intersecting circle model to describe the cross-section of twisted fiber yarns,and a physics-based theoretical model to predict the effective tensile moduli.The numerical models take into account the cross-sectional characteristic and the twist architecture.The investigation shows that:the sum of each fiber area should be used for experimental analysis;and the crosssectional area surrounded by the yarn profile should be used for theoretical predictions and finite element(FE)simulations.The relative errors of the prediction method and the FE simulation are less than 2%and 1%,respectively.The friction between the fibers is derived,and the effect of friction on mechanical properties is discussed.The investigation method will serve as a fundamental component of twisted fiber bundle/yarn analysis. | Xuefeng TENG Duoqi SHI Xin JING Shuangqi LYU Xiaoguang YANG | 2021 | Chinese Journal of Aeronautics2021，34，5： | 1 |
| 5 | Discovering Cathodic Biocompatibility for Aqueous Zn–MnO_(2)Battery:An Integrating Biomass Carbon Strategy显示文摘Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2)uniformly loaded on N-doped carbon derived from grapefruit peel is successfully fabricated in this work,and particularly the composite cathode with carbon carrier quality percentage of 20 wt%delivers the specific capacity of 391.2 mAh g^(−1)at 0.1 A g^(−1),outstanding cyclic stability of 92.17%after 3000 cycles at 5 A g^(−1),and remarkable energy density of 553.12 Wh kg^(−1)together with superior coulombic efficiency of~100%.Additionally,the cathodic biosafety is further explored specifically through in vitro cell toxicity experiments,which verifies its tremendous potential in the application of clinical medicine.Besides,Zinc ion energy storage mechanism of the cathode is mainly discussed from the aspects of Jahn–Teller effect and Mn domains distribution combined with theoretical analysis and experimental data.Thus,a novel perspective of the conversion from biomass waste to biocompatible Mn-based cathode is successfully developed. | Wei Lv Zilei Shen Xudong Li Jingwen Meng Weijie Yang Fang Ding Xing Ju Feng Ye Yiming Li Xuefeng Lyu Miaomiao Wang Yonglan Tian Chao Xu | 2024 | Nano-Micro Letters2024，16，6： | 0 |
| 6 | A buried submarine canyon in the northwest South China Sea:architecture,development processes and implications for hydrocarbon exploration显示文摘High-resolution multichannel seismic data enables the discovery of a previous,undocumented submarine canyon(Huaguang Canyon)in the Qiongdongnan Basin,northwest South China Sea.The Huaguang Canyon with a NW orientation is 140 km in length,and 2.5 km to 5 km in width in its upper reach and 4.6 km to 9.5 km in width in its lower reach.The head of the Huaguang Canyon is close to the Xisha carbonate platform and its tail is adjacent to the central canyon.This buried submarine canyon is formed by gravity flows from the Xisha carbonate platform when the sea level dropped in the early stage of the late Miocene(~10.5 Ma).The internal architecture of the Huaguang Canyon is mainly characterized by high amplitude reflections,indicating that this ancient submarine canyon was filled with coarse-grained sediments.The sediment was principally scourced from the Xisha carbonate platform.In contrast to other buried large-scale submarine canyons(central canyon and Zhongjian Canyon)in the Qiongdongnan Basin,the Huaguang Canyon displays later formation time,smaller width and length,and single sediment supply.The coarse-grained deposits within Huaguang Canyon provide a good environment for reserving oil and gas,and the muddy fillings in Huaguang Canyon have been identified as regional caps.Therefore,Huaguang Canyon is potential area for future hydrocarbon exploration in the northwest South China Sea.Our results may contribute to a better understanding of the evolution of submarine canyons formed in carbonate environment. | Bin Wang Fuliang Lyu Shuang Li Jian Li Zhili Yang Li Li Xuefeng Wang Yintao Lu Taotao Yang Jingwu Wu Guozhong Sun Hongxia Ma Xiaoyong Xu | 2021 | Acta Oceanologica Sinica2021，40，3： | 0 |
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