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| 1 | Fusion of machine vision technology and AlexNet-CNNs deep learning network for the detection of postharvest apple pesticide residues显示文摘Pesticide residue is an important factor that affects food safety.In order to achieve effective detection of pesticide residues in apples,a machine-vision-based segmentation algorithm and hyperspectral techniques were used to segment the foreground and background regions of the apple image.By calculating the roundness value and extracting the region with the highest roundness value in the connected region,a region of interest(ROI)maskwas created for the apple.Four pesticides(chlorpyrifos,carbendazimand two mixed pesticides)and an inactive control were used at the same concentration of 100 ppm(except for the control group),and the hyperspectral region of the corresponding sample image was extracted by obtaining the different types of pesticide residues in the ROI masks.To increase the diversity of the samples and to expand the dataset,Gaussianwhite noise with a varying signal-to-noise ratio was added to each of the hyperspectral images of the apple.The number of samples was increased from four types of 12 samples to four types of 72 samples,giving 4608 hyperspectral data images in each category.The structure and parameters of a convolutional neural network(CNN)were determined using theoretical analysis and experimental verification.All the extracted hyperspectral images of apples were normalized to 227×227×3 pixels as the input of the CNN network for pesticide residue detection.There were 18,432 sample data of four types for 72 samples.Of these,12,288 images were selected using a bootstrap sampling method as the training set,and 6144 as the test set,with no overlap.The test results showthatwhen the number of training epochswas 10,the accuracy of the test set detectionwas 99.09%,and the detection accuracy of the single-band average imagewas 95.35%.A comparison with traditional k-nearest neighbor(KNN)and support vectormachine classification algorithms showed that the detection accuracy for KNNwas 43.75%and the average time was 0.7645 s.These results demonstrate that our method is a small-sample,noncontact,fast,effective and low-cost technique that can provide effective pesticide residue detection in postharvest apples. | Bo Jiang Jinrong He Shuqin Yang Hongfei Fu Tong Li Huaibo Song Dongjian He | 2019 | Artificial Intelligence in Agriculture2019，，1： | 8 |
| 2 | Tuning exsolution of nanoparticles in defect engineered layered perovskite oxides for efficient CO_(2) electrolysis显示文摘Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC. | Zhengrong Liu Jun Zhou Yueyue Sun Xiangling Yue Jiaming Yang Lei Fu Qinyuan Deng Hongfei Zhao Chaofan Yin Kai Wu | 2023 | Journal of Energy Chemistry2023，，9： | 1 |
| 3 | Time-resolved chemiluminescence strategy for multiplexed immunoassay of clenbuterol and ractopamine显示文摘 | Jing Han Hongfei Gao Wenwen Wang Zhenxing Wang Zhifeng Fu | 2013 | Biosensors and Bioelectronics2013，，： | 1 |
| 4 | Evaluation of antioxidant activities of principal carotenoids available in water spinach (lpomoea aquatica)显示文摘 | FU Hongfei XIE Bijun MA Shaojun | 2011 | Journal of Food Composition and Analysis2011，24，2： | 1 |
| 5 | Effect of esterification with fatty acid of β-cryptoxanthin on its thermal stability and antioxidant activity by chemiluminescence method显示文摘 | HongFei Fu BiJun Xie Gang Fan ShaoJun Ma XinRong Zhu SiYi Pan | 2010 | Food Chemistry2010，，3： | 1 |
| 6 | Evaluation of an- tioxidant activities of principal carotenoids available in water spinach ( Ipomoea aquatica) 显示文摘 | Hongfei Fu Bijun Xie Shaojun Ma | 2011 | Journal of Food Composition and Analysis2011，24，： | 1 |
| 7 | Two splitting positive definite mixed finite element methods for parabolic integro-differential equations显示文摘 | Hui Guo Jiansong Zhang Hongfei Fu | 2012 | Applied Mathematics and Computation2012，，22： | 1 |
| 8 | Finite Element Approximation of Semilinear Parabolic Optimal Control Problems显示文摘In this paper,the finite element approximation of a class of semilinear parabolic optimal control problems with pointwise control constraint is studied.We discretize the state and co-state variables by piecewise linear continuous functions,and the control variable is approximated by piecewise constant functions or piecewise linear discontinuous functions.Some a priori error estimates are derived for both the control and state approximations.The convergence orders are also obtained. | Hongfei Fu Hongxing Rui | 2011 | Numerical Mathematics(Theory,Methods and Applications)2011，4，4： | 1 |
| 9 | ANALYSIS OF A MULTI-TERM VARIABLE-ORDER TIME-FRACTIONAL DIFFUSION EQUATION AND ITS GALERKIN FINITE ELEMENT APPROXIMATION显示文摘In this paper,we study the well-posedness and solution regularity of a multi-term variable-order time-fractional diffusion equation,and then develop an optimal Galerkin finite element scheme without any regularity assumption on its true solution.We show that the solution regularity of the considered problem can be affected by the maximum value of variable-order at initial time t=0.More precisely,we prove that the solution to the multi-term variable-order time-fractional diffusion equation belongs to C 2([0,T])in time provided that the maximum value has an integer limit near the initial time and the data has sufficient smoothness,otherwise the solution exhibits the same singular behavior like its constant-order counterpart.Based on these regularity results,we prove optimalorder convergence rate of the Galerkin finite element scheme.Furthermore,we develop an efficient parallel-in-time algorithm to reduce the computational costs of the evaluation of multi-term variable-order fractional derivatives.Numerical experiments are put forward to verify the theoretical findings and to demonstrate the efficiency of the proposed scheme. | Huan Liu Xiangcheng Zheng Hongfei Fu | 2022 | Journal of Computational Mathematics2022，40，5： | 0 |
| 10 | A CHARACTERISTIC FINITE ELEMENT METHOD FOR CONSTRAINED CONVECTION-DIFFUSION-REACTION OPTIMAL CONTROL PROBLEMS显示文摘 | Hongfei Fu Hongxing Rui Hui Guo | 2013 | Journal of Computational Mathematics2013，31，1： | 0 |
| 11 | COMPENSATION FOR THE EFFECTS OF MUTUAL COUPLING ON THE PERFORMANCE OF ADAPTIVE ARRAYS显示文摘Using the Method of Moments(MoM) and the spectral method, the effect of mutual coupling on the performance of adaptive arrays is compensated. First, the MoM is used to compute the behavior of the array, where the accurate analytical model and odd nnmbers of piecewise sinusoids are applied. Then the covariance matrix with mutual coupling being taken into account is analyzed, and the expression for the weight of the Least Mean Square(LMS)algorithm with mutual coupling being compensated is given. Finally, the method given in this letter is tested on an example. | Gao Xue Hu Hongfei Fu Demin (National Key Lab. of Antennas and Microwave Technology, Xidian University, Xi’an 710071) | 2002 | Journal of Electronics(China)2002，19，1： | 0 |
| 12 | ANALYSIS OF THE EFFECT OF THE TRUNCATED SCAN PLANE IN TIME-DOMAIN NEAR-FIELD MEASUREMENTS显示文摘The thought and formulation for near-field far-field transformation based on the direct time-domain computation scheme are given. The effect of the truncated scan plane is investigated by simulating time-domain measurement of an open-ended waveguide antenna, and a simple and effective criterion is derived for removing the truncation errors in the practical time-domain near-field measurements. | Hu Hongfei Gao Xue Fu Demin(National Key Lab. of Antennas and Microwave Technology, Xidian University, Xi’an 710071) | 2002 | Journal of Electronics(China)2002，19，1： | 0 |
| 13 | Green synthesis of ZSM-5 using silica fume and catalytic co-cracking of lignin and plastics for production of monocyclic aromatics显示文摘ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates.The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 μm and weak acid-dominated with proper Brønsted(B)and Lewis(L)acid sites.The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol,lowdensity polyethylene(LDPE)and alkali lignin(AL)to enhance the production of benzene,toluene,ethylbenzene and xylene(BTEX).The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3,under the condition,the achieved BTEX selectivity were 24%and 33%(mass)higher than the calculated values(weighted average).The highest BTEX selectivity reached 88.5%,which was 3.7%and 54.2%higher than those from individual cracking LDPE and AL.The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5,indicating potential application prospect. | Hongbing Fu Yufei Gu Tianhua Gao Fuwei Li Hengshuo Gu Hucheng Ge Yuke Liu Zhixia Li Hongfei Lin Jiangfei Cao | 2024 | Chinese Journal of Chemical Engineering2024，65，1： | 0 |
| 14 | A posteriori error estimates for optimal control problems constrained by convection-diffusion equations显示文摘我们建议进化类型传送对流散开的典型有限元素 discretization 最佳的控制问题。Nondivergence 免费的速度地和双边的不平等控制限制被处理。然后,一个 posteriori 错误估计的某剩余类型为控制,状态,和伴随状态的近似被分析。基于导出的错误评估者,我们在开发有效多集合把他们用作错误指示物适应网孔特征为如此的最佳的控制问题的有限元素算法。最后,一个数字例子被给检查多集合的可行性和有效性适应网孔精炼。 | Hongfei FU Hongxing RUI Zhaojie ZHOU | 2016 | Frontiers of Mathematics in China2016，11，1： | 0 |
| 15 | An Efficient Second-Order Finite Volume ADI Method for Nonlinear Three-Dimensional Space-Fractional Reaction-Diffusion Equations显示文摘In this paper,a three-dimensional time-dependent nonlinear Riesz spacefractional reaction-diffusion equation is considered.First,a linearized finite volume method,named BDF-FV,is developed and analyzed via the discrete energy method,in which the space-fractional derivative is discretized by the finite volume element method and the time derivative is treated by the backward differentiation formulae(BDF).The method is rigorously proved to be convergent with second-order accuracy both in time and space with respect to the discrete and continuous L2 norms.Next,by adding high-order perturbation terms in time to the BDF-FV scheme,an alternating direction implicit linear finite volume scheme,denoted as BDF-FV-ADI,is proposed.Convergence with second-order accuracy is also strictly proved under a rough temporal-spatial stepsize constraint.Besides,efficient implementation of the ADI method is briefly discussed,based on a fast conjugate gradient(FCG)solver for the resulting symmetric positive definite linear algebraic systems.Numerical experiments are presented to support the theoretical analysis and demonstrate the effectiveness and efficiency of the method for large-scale modeling and simulations. | Bingyin Zhang Hongfei Fu Xueting Liang Jun Liu Jiansong Zhang | 2022 | Advances in Applied Mathematics and Mechanics2022，14，6： | 0 |
| 16 | Distinct structural characteristics define a new subfamily of Mycoplasma ferritin显示文摘Ferritins can generally be divided into four subfamilies based on their structural characteristics,namely,the classic ferritins(Ftns),bacterioferritins(Bfrs),DNA-binding proteins from starved cells(Dps’),and encapsulated ferritins(Enc Ftns).However,the ferritin from Mycoplasma penetrans(Mpef)possesses a particular ferroxidase center with an extreme low activity and exhibits unusual characteristics,indicating that it could be a member of a quite different subfamily of ferritins.Hereby,the crystal structure of the ferritin from Ureaplasma urealyticum(Uurf)is presented,Mpef and Uurf have very similar properties,though they display very low sequence similarity.Thus,ferritins from Mycoplasma with these unique properties do not belong to any known subfamily,but they should rather be placed in a novel ferritin subfamily,which we term Mycoplasma Ferritin(Mfr). | Wenming Wang Xiaojia Liu Yajie Wang Yuan Wang Dan Fu Hongfang Xi Yi Zhao Hongfei Wang | 2022 | Chinese Chemical Letters2022，33，11： | 0 |
| 17 | Peroxidase-like single Fe atoms anchored on Ti_(3)C_(2)T_(x)MXene as surface enhanced Raman scattering substrate for the simultaneous discrimination of multiple antioxidants显示文摘Single-atom nanozymes(SAzymes)are emerging as promising alternatives to mimic natural enzyme,which is due to high atomic utilization efficiency,well-defined geometric,and unique electronic structure.Herein,Fe single atoms supported on Ti_(3)C_(2)T_(x)(Fe-SA/Ti_(3)C_(2)T_(x))with intrinsic peroxidase activity is developed,further constructing a sensitive Raman sensor array for sensing of five antioxidants.Fe-SA/Ti_(3)C_(2)T_(x)shows excellent peroxidase-like performance in catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)with colorimetric reactions.X-ray adsorption fine structure(XAFS)reveals that the electron transport between the Ti_(3)C_(2)T_(x)and Fe atoms occurs along Fe-O-Ti ligands,meanwhile the density functional theory(DFT)calculations confirm the spontaneous dissociation of H_(2)O_(2)and the formation of OH radicals.Furthermore,the peroxidase-like Fe-SA/Ti_(3)C_(2)T_(x)was used as surface enhanced Raman scattering(SERS)substrate of oxidized TMB(TMB+)and achieved satisfied signal amplification performance.Using the blocking effects of free radical reactions,one-off identification of 5 antioxidants,including ascorbic acid(AA),uric acid(UA),glutathione(GSH),melatonin(Mel),and tea polyphenols(TPP),could be realized with this high identifiable catalytic property.This principle could realize 100%distinguish accuracy combined with linear discriminant analysis(LDA)and heat map data analysis.A wide detection concentration ranges from 10^(-8)to 10^(-3)M for five antioxidants was also achieved. | Hongyan Xi Hongfei Gu Yurui Han Tingting You Pengfei Wu Qingqing Liu Lirong Zheng Shuhu Liu Qiang Fu Wenxing Chen Yukun Gao Yuting Wang Penggang Yin | 2023 | Nano Research2023，16，7： | 0 |
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