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DLF-YOLOF:an improved YOLOF-based surface defect detection for steel plate

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Journal of Iron and Steel Research International 2024年第2期31卷 442-451页

作者： guang-hu Liu Mao-xiang chu Rong-fen Gong Ze-hao Zheng School of Electronic and Information Engineering University of Science and Technology LiaoningAnshan114051LiaoningChina

Surface defects can affect the quality of steel *** methods based on computer vision are currently applied to surface defect detection of steel ***,their real-time performance and object detection of small defect are still *** improved object detection network based on You Only Look One-level Feature(YOLOF)is proposed to show excellent performance in surface defect detection of steel plate,called ***,the anchor-free detector is used to reduce the network ***,deformable convolution network and local spatial attention module are introduced into the feature extraction network to increase the contextual information in the feature ***,the soft non-maximum suppression is used to improve detection accuracy ***,data augmentation is performed for small defect objects during training to improve detection *** show the average precision and average precision for small objects are 42.7%and 33.5%at a detection speed of 62 frames per second on a single GPU,*** shows that DLF-YOLOF has excellent performance to meet the needs of industrial real-time detection.

关键词： Steel surface defects detection YOLOF Anchor-free detector Small object detection Real-time detection

An Improved Model of the Jovian Magnetosphere

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Chinese Physics Letters 2014年第3期31卷 184-186页

作者： LU Bin chen chu-Xin Key Laboratory of Geospace Environment Department of Geophysics and Planetary Sciences School of Earth and Space Sciences University of Science and Technology of China Hefei 230026

The Jovian magnetosphere is modulated by the solar wind and centrifugal force. The configuration of the magnetic field in the previous model of the magnetosphere including the centrifugal force is consistent with the observations at low magnetic latitude （Λ〈50°）, while there is a substantial difference between the results of the model and the observations at high magnetic latitude （Λ≥50°）, especially in the distant magnetotail. Based on the previous model, a new configuration of the Jovian magnetosphere in the night side is suggested by a three-step transformation in this study. The new magnetosphere obtained by the transformation method is flattened in the z-direction and stretched in the x-direction in distant magnetotail, which agree with general knowledge.

关键词： JUPITER (Planet) MAGNETOSPHERE RESEARCH SOLAR wind CENTRIFUGAL force PHYSICS research

Turbulence Modulations in the Boundary Layer of a Horizontal Particle-Laden Channel Flow

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Chinese Physics Letters 2010年第6期27卷 129-132页

作者： LI Jing LIU Zhao-Hui WANG Han-Feng chen Sheng LIU Ya-Ming HAN Hai-Feng ZHENG chu-guang State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074

Turbulence modulations are experimentally investigated using particle image velocimetry （PIV） in the lower boundary layer of a fully developed horizontal channel flow. A simultaneous two-phase PIV measurement technique is adopted to acquire the turbulent statistics quantities and to examine the coherent structures in the near-wall region. Polythene beads with diameters of 60 μm are used as dispersed phases, and the PIV measurements have been performed at three mass loadings varying from 2.5 ×10^-4 to 5 × 10^-3. All the experiments are performed at a wall shear Reynolds number of Reτ = 430. The results show that the presence of the particles suppresses the coherent structures, with shorter streamwise extent of the quasistrearnwise structures, and then, the wall-normal velocity fluctuations and shear Reynolds stresses are both decreased in the near-core region. In addition, as a result of the particle wake, the turbulence intensity and shear Reynolds stress both increase in the vicinity of the wall. Due to the drag effects of the particles on the gas, the streamwise velocity gradients decrease in the outer region and increase in the viscous sublayer, meanwhile the thickness of the viscous sublayer also decreases. These results cause the peak values of the streamwise velocity fluctuations adjacent to the wall to increase, and the peak positions shift to the wall. This is the reason for decreasing the near-wall region and increasing the near-core region of the streamwise velocity fluctuations in appearance.

关键词： Reynolds stress Wakes Flow in channels Turbulence intensities Statistical analysis Drag

Changes in the activities of key enzymes and the abundance of functional genes involved in nitrogen transformation in rice rhizosphere soil under different aerated conditions

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Journal of Integrative Agriculture 2023年第3期22卷 923-934页

作者： XU chun-mei XIAO De-shun chen Song chu guang LIU Yuan-hui ZHANG Xiu-fu WANG Dan-ying The State Key Laboratoty of Rice Biology China National Rice Research InstituteHangzhou 310006P.R.China

Soil microorganisms play important roles in nitrogen transformation. The aim of this study was to characterize changes in the activity of nitrogen transformation enzymes and the abundance of nitrogen function genes in rhizosphere soil aerated using three different methods(continuous flooding(CF), continuous flooding and aeration(CFA), and alternate wetting and drying(AWD)). The abundances of amoA ammonia-oxidizing archaea(AOA) and ammonia-oxidizing bacteria(AOB), nirS, nirK, and nifH genes, and the activities of urease, protease, ammonia oxidase, nitrate reductase, and nitrite reductase were measured at the tillering(S1), heading(S2), and ripening(S3) stages. We analyzed the relationships of the aforementioned microbial activity indices, in addition to soil microbial biomass carbon(MBC) and soil microbial biomass nitrogen(MBN), with the concentration of soil nitrate and ammonium nitrogen. The abundance of nitrogen function genes and the activities of nitrogen invertase in rice rhizosphere soil were higher at S2 compared with S1 and S3 in all treatments. AWD and CFA increased the abundance of amoA and nifH genes, and the activities of urease, protease, and ammonia oxidase, and decreased the abundance of nirS and nirK genes and the activities of nitrate reductase and nitrite reductase, with the effect of AWD being particularly strong. During the entire growth period, the mean abundances of the AOA amoA, AOB amoA, and nifH genes were 2.9, 5.8, and 3.0 higher in the AWD treatment than in the CF treatment, respectively, and the activities of urease, protease, and ammonia oxidase were 1.1, 0.5, and 0.7 higher in the AWD treatment than in the CF treatment, respectively. The abundances of the nirS and nirK genes, and the activities of nitrate reductase and nitrite reductase were 73.6, 84.8, 10.3 and 36.5% lower in the AWD treatment than in the CF treatment, respectively. The abundances of the AOA amoA, AOB amoA, and nifH genes were significantly and positively correlated wi

关键词： rhizosphere aeration gene abundance enzyme activities soil microbial biomass carbon soil microbial nitrogen

Risk assessment of gas control and spontaneous combustion of coal under gas drainage of an upper tunnel

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International Journal of Mining Science and Technology 2019年第3期29卷 491-498页

作者： Tingxiang chu Pin Li Yuexia chen School of Safety Engineering North China Institute of Science and TechnologySanhe 065201China School of Safety Science and Engineering Henan Polytechnic UniversityJiaozuo 454003China

The adjustment of the gas drainage rate has an immediate impact on air leakage in gob,thus resulting in the change of self-heating of *** regulating the gas drainage parameters,the risk of spontaneous combustion of coal should be *** risk assessment of gas control and spontaneous combustion of coal under gas drainage in a tunnel was investigated at different gas drainage *** distributions of the air volume along the working face,the gas management effects and the width of the oxidation zone were subjected to risk *** the simulation results showed,with increasing gas drainage rate,although the safety of gas dilution by ventilation was assured,the intensifying air leakage caused the oxidation zone to move into the deeper gob and led to an increase in the width of the oxidation zone.A risk assessment method was proposed to determine a suitable gas drainage rate for the upper *** correctness of the risk assessment and the validity of the numerical modelling were confirmed by the field measurements.

关键词： Gas drainage Risk assessment Air leakage Oxidation zone Spontaneous combustion

Metalizing reduction and magnetic separation of vanadium titano-magnetite based on hot briquetting

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International Journal of Minerals,Metallurgy and Materials 2014年第3期21卷 225-233页

作者： Shuang-yin chen Man-sheng chu School of Materials and Metallurgy Northeastern University

To achieve high efficiency utilization of Panzhihua vanadium titano-magnetite, a new process of metalizing reduction and magnetic separation based on hot briquetting is proposed, and factors that affect the cold strength of the hot-briquetting products and the efficiency of reduction and magnetic separation are successively investigated through laboratory experiments. The relevant mechanisms are elucidated on the basis of microstructural observations. Experimental results show that the optimal process parameters for hot briquetting include a hot briquetting temperature of 475°C, a carbon ratio of 1.2, ore and coal particle sizes of less than 74 μm. Additionally, with respect to metalizing reduction and magnetic separation, the rational parameters include a magnetic field intensity of 50 mT, a reduction temperature of 1350°C, a reduction time of 60 min, and a carbon ratio of 1.2. Under these above conditions, the crushing strength of the hot-briquetting agglomerates is 1480 N, and the recovery ratios of iron, vanadium, and titanium are as high as 91.19%, 61.82%, and 85.31%, respectively. The new process of metalizing reduction and magnetic separation based on hot briquetting demonstrates the evident technological advantages of high efficiency separation of iron from other valuable elements in the vanadium titano-magnetite.

关键词： magnetite hot briquetting ore reduction magnetic separation

20-Hydroxyecdysone Improves Neuronal Differentiation of Adult Hippocampal Neural Stem Cells in High Power Microwave Radiation-Exposed Rats

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Biomedical and Environmental Sciences 2022年第6期35卷 504-517页

作者： LIU Jing Jing ZHANG Hong Yan chen Xin ZHANG guang Bin LIN Jiang Kai FENG Hua chu Wei Hua Department of Neurosurgery and Key Laboratory of Neurotrauma Southwest HospitalThird Military Medical University(Army Medical University)Chongqing 400038China Department of Occupational Health Faculty of Preventive MedicineThird Military Medical University(Army Medical University)Chongqing 400038China

Objective The hippocampus is thought to be a vulnerable target of microwave *** aim of the present study was to investigate whether 20-hydroxyecdysone(20E)acted as a fate regulator of adult rat hippocampal neural stem cells(NSCs).Furthermore,we investigated if 20E attenuated high power microwave(HMP)radiation-induced learning and memory *** Sixty male Sprague-Dawley rats were randomly divided into three groups:normal controls,radiation treated,and radiation+20E *** in the radiation and radiation+20E treatment groups were exposed to HPM radiation from a microwave emission *** learning and memory abilities of the rats were assessed using the Morris water maze *** adult rat hippocampal NSCs were isolated in vitro and cultured to evaluate their proliferation and *** addition,hematoxylin&eosin staining,western blotting,and immunofluorescence were used to detect changes in the rat brain and the proliferation and differentiation of the adult rat hippocampal NSCs after HPM radiation *** The results showed that 20E induced neuronal differentiation of adult hippocampal NSCs from HPM radiation-exposed rats via the Wnt3a/β-catenin signaling pathway in ***,20E facilitated neurogenesis in the subgranular zone of the rat brain following HPM radiation *** of 20E attenuated learning and memory deficits in HPM radiation-exposed rats and frizzled-related protein(FRZB)reduced the 20E-induced nuclear translocation ofβ-catenin,while FRZB treatment also reversed 20E-induced neuronal differentiation of NSCs in *** These results suggested that 20E was a fate regulator of adult rat hippocampal NSCs,where it played a role in attenuating HPM radiation-induced learning and memory deficits.

关键词： High power microwave Hippocampus 20-hydroxyecdysone Learning and memory

A hybrid CNN-LSTM model for diagnosing rice nutrient levels at the rice panicle initiation stage

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Journal of Integrative Agriculture 2024年第2期23卷 711-723页

作者： Fubing Liao Xiangqian Feng Ziqiu Li Danying Wang chunmei Xu guang chu Hengyu Ma Qing Yao Song chen School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China China National Rice Research Institute Chinese Academy of Agricultural SciencesHangzhou 310006China School of Agriculture Yangtze UniversityJingzhou 434025China

Nitrogen(N)and potassium(K)are two key mineral nutrient elements involved in rice *** diagnosis of N and K status is very important for the rational application of fertilizers at a specific rice growth ***,we propose a hybrid model for diagnosing rice nutrient levels at the early panicle initiation stage(EPIS),which combines a convolutional neural network(CNN)with an attention mechanism and a long short-term memory network(LSTM).The model was validated on a large set of sequential images collected by an unmanned aerial vehicle(UAV)from rice canopies at different growth stages during a two-year *** with VGG16,AlexNet,GoogleNet,DenseNet,and inceptionV3,ResNet101 combined with LSTM obtained the highest average accuracy of 83.81%on the dataset of Huanghuazhan(HHZ,an indica cultivar).When tested on the datasets of HHZ and Xiushui 134(XS134,a japonica rice variety)in 2021,the ResNet101-LSTM model enhanced with the squeeze-and-excitation(SE)block achieved the highest accuracies of 85.38 and 88.38%,*** the cross-dataset method,the average accuracies on the HHZ and XS134 datasets tested in 2022 were 81.25 and 82.50%,respectively,showing a good *** proposed model works with the dynamic information of different rice growth stages and can efficiently diagnose different rice nutrient status levels at EPIS,which are helpful for making practical decisions regarding rational fertilization treatments at the panicle initiation stage.

关键词： dynamic model of deep learning UAV rice panicle initiation nutrient level diagnosis image classification

An Evaluation of Metronidazole Degradation in a Plasma-Assisted Rotating Disk Reactor Coupled with TiO2 in Aqueous Solution

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Engineering 2021年第11期7卷 1603-1610页

作者： Yong Cai guang-Wen chu Yong Luo Meng-Jun Su Bao-Ju Wang Bao-Chang Sun Jian-Feng chen State Key Laboratory of Organic–Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High-Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China

Pollution involving pharmaceutical components in bodies of water is an increasingly serious environmental *** discharge for the degradation of antibiotics is an emerging technology that may be relevant toward addressing this *** this work,a plasma-assisted rotating disk reactor(plasma-RDR)and a photocatalyst—namely,titanium dioxide(TiO_(2))—were coupled for the treatment of metronidazole(MNZ).Discharge uniformity was improved by the use of a rotating electrode in the plasma-RDR,which contributed to the utilization of ultraviolet(UV)light radiation in the presence of TiO_(2).The experimental results showed that the degradation efficiency of MNZ and the concentration of generated hydroxyl radicals respectively increased by 41%and 2.954 mg∙L^(-1) as the rotational speed increased from 0 to 500 r∙min^(-1).The synergistic effect of plasma-RDR plus TiO_(2) on the generation of hydroxyl radicals was *** intermediate products were identified using three-dimensional(3D)excitation emission fluorescence matrices(EEFMs)and liquid chromatography-mass spectrometry(LC-MS),and a possible degradation pathway is proposed *** plasma-catalytic process has bright prospects in the field of antibiotics degradation.

关键词： Plasma-assisted rotating disk reactor Pulsed discharge Metronidazole Degradation TiO_(2)