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Chinese Journal of Mechanical engineering 2017年第2期30卷 231-240页

作者： Hong MIAO Cheng JIANG Sixing LIU Shanwen ZHANG Yanjun ZHANG college of Mechanical engineering Yangzhou UniversityYangzhou 225009China Key Laboratory of modem Agricultural Equipment Nanjing Research Institute for Agricultural Mechanization Ministry of AgricultureNanjing 210014China

The adoption of cold-extrusion forming for internal thread net forming becomes an important component of anti-fatigue processing with the development of internal thread processing towards high performance, low cost and low energy consumption. It has vast application foreground in the field of aviation, spaceflight, high speed train and etc. The internal thread processing and anti-fatigue manufacture technology are summarized. In terms of the perspective of processing quality and fatigue serving life, the advantages and disadvantages of the processing methods from are compared. The internal thread cold-extrusion processing technology is investigated for the purpose of improving the anti-fatigue serving life of internal thread. The superiorities of the plastic deformation law and surface integrity of the metal layer in the course of cold extrusion for improving its stability and economy are summed up. The proposed research forecasts the develop- ment tendency of the internal thread anti-fatigue manufacturing technology.

关键词： High-strength steel · Internal thread · Coldextrusion · Anti-fatigue · Surface integrity

Shortwave infrared hyperspectral imaging for detection of pH value in Fuji apple

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International Journal of Agricultural and Biological engineering 2014年第2期7卷 130-137页

作者： Guo Zhiming Huang Wenqian Chen Liping Peng Yankun Wang Xiu Beijing research center of Intelligent Equipment for agriculture Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China college of engineering China Agricultural UniversityBeijing 100097China National engineering research center of Intelligent Equipment for agriculture Beijing 100097China

pH value is regarded as one of the most important attributes that affect sensory characteristics and edible quality of *** objective of the research was to explore the feasibility of applying shortwave infrared hyperspectral imaging system to detect the pH value of apple.A shortwave infrared hyperspectral imaging system was developed over the wavelength region of 1000-2500 nm and used to acquire hyperspectral images of apple *** reflectance calibration,mean reflectance spectral was calculated by averaging the intensity of all pixels within the roundness region of interest(ROI).Synergy interval partial least squares(siPLS)algorithms as an effective multivariable method was conducted on the calibration of regression model to estimate the pH value in Fuji *** performance of the final model was back-evaluated according to root mean square error of calibration(RMSEC)and correlation coefficient(Rc)in calibration set,and tested in prediction *** optimal prediction siPLS model was obtained with correlation coefficient(Rp)of 0.8474 and mean square error of prediction(RMSEP)of *** results indicated that shortwave infrared hyperspectral imaging combined with siPLS chemometrics could be an accurate and fast method for nondestructive prediction of pH value in Fuji apple.

关键词： shortwave infrared hyperspectral imaging synergy interval partial least squares pH value apple

Identification of a novel cytochrome P450 CYP321B1 gene from tobacco cutworm （Spodoptera litura） and RNA interference to evaluate its role in commonly used insecticides

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Insect Science 2017年第2期24卷 235-247页

作者： Rui-Long Wang Keyan Zhu-Salzman Scott R. Baerson Xiao-Wei Xin Jun Li Yi-Juan Su Ren-Sen Zeng Key Laboratory of Tropical Agro-Environment Ministry of Agriculture College of Natural Resources and Environment South China Agri- cultural University Guangzhou China college of Life Sciences Fujian Agriculture and Forestry University Fuzhou China Departments of Entomology Texas A&M University Texas United States Department of agriculture-Agricultural research Service Natural Products Utilization Research Unit University Mississippi USA Guangdong engineering research center for modem Eco-agriculture and Circular agriculture Guangzhou China

Insect cytochrome P450 monooxygenases （CYPs or P450s） play an important role in detoxifying insecticides leading to resistance in insect populations. A polyphagous pest, Spodoptera litura, has developed resistance to a wide range of insecticides. In the present study, a novel P450 gene, CYP321B1, was cloned from S. litura. The function of CYP321B1 was assessed using RNA interference （RNAi） and monitoring resistance levels for three commonly used insecticides, including chlorpyrifos, β-cypermethrin and methomyl. The full-length complementary DNA sequence of CYP321B1 is 1814 bp long with an open reading frame of 1 488 bp encoding 495 amino acid residues. Quantitative reverse-transcriptase polymerase chain reaction analyses during larval and pupal develop- ment indicated that CYP321B1 expression was highest in the midgut of fifth-instar larvae, followed by fat body and cuticle. The expression of CYP321B1 in the midgut was up- regulated by chlorpyrifos,β-cypermethrin and methomyl with both lethal concentration at 15% （LC15）（50, 100 and 150 μg/mL, respectively） and 50%（LC50） dosages （100,200 and 300μg/mL, respectively）. Addition of piperonyl butoxide （PBO） significantly increased the toxicity ofchlorpyrifos,β-cypermethrin and methomyl to S. litura, suggesting a marked synergism of the three insecticides with PBO and P450-mediated detoxification. RNAi- mediated silencing of CYP321B1 further increased mortality by 25.6% and 38.9% when the fifth-instar larvae were exposed to chlorpyrifos and β-cypermethrin, respectively, at the LCso dose levels. The results demonstrate that CYP321B1 might play an important role in chlorpyrifos and β-cypermethrin detoxification in S. litura.

关键词： CYP321B1 cytochrome P450 monooxygenases insecticide resistance RNAinterference Spodoptera litura

6-Benzylaminopurine treatment maintains the quality of Chinese chive(Allium tuberosum Rottler ex Spreng.) by enhancing antioxidant enzyme activity

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Journal of Integrative agriculture 2017年第9期16卷 1968-1977页

作者： JIA Li-e LIU Sheng DUAN Xiao-ming ZHANG Chao WU Zhan-hui LIU Ming-chi GUO Shao-gui ZUO Jin-hua WANG Li-bin Key Laboratory of urban agriculture (North) Ministry of Agriculture/Key Laboratory of Vegetable Postharvest ProcessingMinistry of Agriculture/Key Laboratory of Vegetable Postharvest ProcessingMinistry of Agriculture/Beijing Key Laboratory of Fruits and Vegetable Storage and ProcessingNational Engineering Research Center for VegetablesBeijing Academy of Agriculture and Forestry Sciences college of Food Science and Technology Yangzhou University

Chinese chive usually develops an off-flavor after a short storage time. To explore effective ways to maintain the postharvest quality of Chinese chive, the effect of exogenous application of 6-benzylaminopurine（6-BA） on postharvest quality and antioxidant activity of chive was evaluated, and the mechanism of the physiological responses of chive to 6-BA treatment was explored. Chives were sprayed for 10 min with 100, 300, or 500 mg L–1 6-BA or with alkaline solution as the control, then stored at（2±1）°C with a relative humidity（RH） of 80–85%. We found that 300 mg L–1 6-BA significantly delayed yellowing and chlorophyll degradation, maintained the total phenolic and flavonoid content, and improved the activities of antioxidant enzymes, including superoxide dismutase（SOD）, catalase（CAT） and peroxidase（POD）. In conclusion, we identified exogenous application of 6-BA as an effective method for maintaining postharvest quality of Chinese chive. In addition, our finding that the activities of antioxidant enzymes increase in response to exogenous 6-BA provides new insights into the mechanism of cytokinin-based postharvest fresh-keeping.

关键词： 6-benzylaminopurine(6-BA) Chinese chive postharvest quality antioxidant activity

Over-Expression of Bn MAPK1 in Brassica napus Enhances Tolerance to Drought Stress

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Journal of Integrative agriculture 2014年第11期13卷 2407-2415页

作者： WENG Chang-mei LU Jun-xing WAN Hua-fang WANG Shu-wen WANG Zhen LU Kun LIANG Ying college of Agronomy and Biotechnology Southwest University Chongqing Rapeseed engineering & Technology research center engineering research center of South Upland agriculture Ministry of Education

Mitogen-activated protein kinases （MAPKs） are a family of Ser/Thr protein kinases widely conserved in all eukaryotes and involved in responses to biotic and abiotic stresses. In this study, two over-expressing BnMAPK1 oilseed rape lines, ov3 and ov11, were used to study the drought-resistant mechanism of BnMAPK1 under natural drought and simulation drought through spraying 10%PEG 8000 in seedlings. Zhongyou 821 （WT） was used as control. Compared with wild type, transgenic seedlings had higher leaf water content, higher root activity, slightly higher peroxidase （POD） and superoxide dismutase （SOD） activity, higher proline content and lower malondialdehyde （MDA） content. The expression of drought-resistant related genes, including P5CSB, PLC, LEA4 and SCE1, have been up-regulated in some degree and the expressed time of transgenic lines were earlier than that of wild type. These results suggested that over-expression of BnMAPK1 can enhance the resistance to drought in oilseed rape （Brassica napus）.

关键词： MAPK Brassica napus transgenic drought-stress qRT-PCR

Preparation and characterization of NaYF_4:Er^(3+),Tm^(3+)@NaYF_4:Ce^(3+),Tb^(3+) microcrystals with dual-mode emissions at the single-particle level

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Journal of Rare Earths 2020年第7期38卷 697-704,I0001页

作者： Xianfu Jiao Weihao Ye Qiying Huang Jie Luo Linliang Yu Xiaotang Liu Guangdong engineering Technology research center for Optical agriculture College of Materials and EnergySouth China Agricultural UniversityGuangzhou 510642China

Under hydrothermal environment,we synthesized lanthanide ions doped sodium yttrium fluoride(NaYF4:Er,Tm@NaYF4:Ce,Tb) luminescent microcrystals via an epitaxial growth *** structure and morphology of these microcrystals were examined by SEM,TEM,EDS and XRD *** particles show dual-mode emissions with red upconversion(UC) and green down conversion(DC) as single particles *** mean length and diameter of these microparticles increase from 0.43 to2.26 μm and from 1.33 to 1.86 μm,*** interestingly,the photoluminescence properties of NaYF4:Er,Tm@NaYF4:Ce,Tb phosphor crystals are highly dependent on the crystallite *** microcrystals fluoresce emit dual-mode emissions when they are solid or dispersed in *** its intensive fluorescence and uniform morphology,these materials hold great potential for security and anti-counterfeiting applications.

关键词： NaYF4 microcrystals Dual-mode fluorescence materials Single-particles Core-shell Hydrothermal Rare earths

Spatial and Temporal Characteristics of Rice Potential Productivity and Potential Yield Increment in Main Production Regions of China

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Journal of Integrative agriculture 2013年第1期12卷 45-56页

作者： JIANG Xiao-jian TANG Liang LIU Xiao-jun CAO Wei-xing ZHU Yan National engineering and Technology center for Information agriculture Ministry of Industry and Information Technology/Key Laboratory for Information AgricultureScience and Technology Department of Jiangsu Province/College of AgricultureNanjing Agricultural University

The vast area and marked variation of China make it difficult to predict the impact of climate changes on rice productivity in different ***,analyzing the spatial and temporal characteristics of rice potential productivity and predicting the possible yield increment in main rice production regions of China is important for guiding rice production and ensuring food *** meteorological data of main rice production regions from 1961 to 1970（the 1960s） and from 1996 to 2005（the 2000s） provided by 333 stations,the potential photosynthetic,photo-thermal and climatic productivities in rice crop of the 1960s and 2000s in main rice production regions of China were predicted,and differences in the spatial and temporal distribution characteristics between two decades were ***,the potential yield increment based on the high yield target and actual yield of rice in the 2000s were *** with the 1960s,the potential photosynthetic productivity of the 2000s was seen to have decreased by 5.40%,with rates in northeastern and southwestern China found to be lower than those in central and southern *** potential photo-thermal productivity was generally seen to decrease（2.56%） throughout main rice production regions,decreasing most in central and southern ***,an increase was seen in northeastern and southwestern *** potential climatic productivity was observed to be lower（7.44%） in the 2000s compared to the 1960s,but increased in parts of central and southern *** potential yield increment from the actual yield to high yield target in the 2000s were no more than 6×103 kg ha-1 and ranged from 6×103 to 12×103 kg ha-1 in most of the single-and double-cropping rice growing regions,*** yield increasing potential from the high yield target to the potential photo-thermal productivity in 2000s were less than 10×103 kg ha-1 and ranged from 10×103 to 30×103 kg ha-1 in most of the single-and double-croppi

关键词： rice photosynthetic productivity photo-thermal productivity climatic productivity yield increment spatial and temporal distribution China

Detection and Identification of Tassel States at Different Maize Tasseling Stages Using UAV Imagery and Deep Learning

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Plant Phenomics 2024年第3期6卷 563-578页

作者： Jianjun Du Jinrui Li Jiangchuan Fan Shenghao Gu Xinyu Guo Chunjiang Zhao Information Technology research center Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China Beijing Key Lab of Digital Plants National Engineering Research Center for Information Technology in AgricultureBeijing 100097China college of Information engineering Northwest A&F UniversityYanglingShanxi 712100 China

The tassel state in maize hybridization fields not only reflects the growth stage of the maize but also reflects the performance of the detasseling *** tassel detection models are primarily used to identify mature tassels with obvious features,making it difficult to accurately identify small tassels or detasseled *** study presents a novel approach that utilizes unmanned aerial vehicles(UAVs)and deep learning techniques to accurately identify and assess tassel states,before and after manually detasseling in maize hybridization *** proposed method suggests that a specific tassel annotation and data augmentation strategy is valuable for substantial enhancing the quality of the tassel training *** study also evaluates mainstream object detection models and proposes a series of highly accurate tassel detection models based on tassel categories with strong data *** addition,a strategy for blocking large UAV images,as well as improving tassel detection accuracy,is proposed to balance UAV image acquisition and computational *** experimental results demonstrate that the proposed method can accurately identify and classify tassels at various stages of *** tassel detection model optimized with the enhanced data achieves an average precision of 94.5%across all *** optimal model combination that uses blocking strategies for different development stages can improve the tassel detection accuracy to 98%.This could be useful in addressing the issue of missed tassel detections in maize hybridization *** data annotation strategy and image blocking strategy may also have broad applications in object detection and recognition in other agricultural scenarios.

关键词： identification different learning imagery detection deep maize stages states tasseling

Non-uniform clustering routing protocol of wheat farmland based on effective energy consumption

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International Journal of Agricultural and Biological engineering 2021年第3期14卷 163-170页

作者： Yisheng Miao Chunjiang Zhao Huarui Wu college of Computer Science Beijing University of TechnologyBeijing 100124China National engineering research center for Information Technology in agriculture Beijing 100097China Beijing research center for Information Technology in agriculture Beijing Academy of Agriculture and Forestry SciencesBeijing100097China

Wireless sensor network(WSN)can achieve real-time data collection and transmission of environment,soil,meteorology,crop physiology and other information in *** data provided by WSN could be used for decision making and management,which is very important in precision *** farmland wireless sensor network has the characteristics of wide coverage area,long planting period,inconvenient energy supply,and serious impact of crop environment on wireless signal *** protocol is an important method to achieve long-term WSN monitoring by selecting an appropriate path with low energy consumption for data *** to the phenomenon of uneven environment and channel parameters caused by intensive crop growth in farmland,a non-uniform clustering routing protocol based on effective energy consumption(UCEEC)was proposed in this *** method combined with the characteristics of multi-path fading of farmland environment *** idea of image segmentation was *** with high similarity were divided into a cluster area by the dissimilarity between nodes in order to improve the intracluster communication ***,a multi-hop path selection method between cluster-heads based on the estimation of two-hop effective energy consumption is *** energy consumption cost factor is calculated by the effective energy consumption and the average energy consumption within the cluster to achieve the minimum and balance of the overall energy consumption of the *** results show that,compared with the existing Maximum Residual Energy Based Routing(MREBR)protocol,minimum Energy Consumption Based Routing(MEC)routing protocols,UCEEC improves the energy balance effect between nodes,prolongs the network life cycle,and realizes efficient energy utilization of wireless sensor network data collection in the complex environment of wheat field.

关键词： farmland wireless sensor networks multi-path fading channel routing protocol energy optimization

Responses of water productivity to irrigation and N supply for hybrid maize seed production in an arid region of Northwest China

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Journal of Arid Land 2017年第4期9卷 504-514页

作者： RAN Hui KANG Shaozhong LI Fusheng DU Taisheng DING Risheng LI Sien TONG Ling center for Agricultural Water research in China China Agricultural University college of agriculture Guangxi University

Water and nitrogen（N） are generally two of the most important factors in determining the crop productivity. Proper water and N managements are prerequisites for agriculture sustainable development in arid areas. Field experiments were conducted to study the responses of water productivity for crop yield（WP_（Y-ET）） and final biomass（WP_（B-ET）） of film-mulched hybrid maize seed production to different irrigation and N treatments in the Hexi Corridor, Northwest China during April to September in 2013 and also during April to September in 2014. Three irrigation levels（70%–65%, 60%–55%, and 50%–45% of the field capacity） combined with three N rates（500, 400, and 300 kg N/hm^2） were tested in 2013. The N treatments were adjusted to 500, 300, and 100 kg N/hm^2 in 2014. Results showed that the responses of WP_（Y-ET） and WP_（B-ET） to different irrigation amounts were different. WP_（Y-ET） was significantly reduced by lowering irrigation amounts while WP_（B-ET） stayed relatively insensitive to irrigation amounts. However, WP_（Y-ET） and WP_（B-ET） behaved consistently when subjected to different N treatments. There was a slight effect of reducing N input from 500 to 300 kg/hm^2 on the WP_（Y-ET） and WP_（B-ET）, however, when reducing N input to 100 kg/hm^2, the values of WP_（Y-ET） and WP_（B-ET） were significantly reduced. Water is the primary factor and N is the secondary factor in determining both yield（Y） and final biomass（B）. Partial factor productivity from applied N（PFP_N） was the maximum under the higher irrigation level and in lower N rate（100–300 kg N/hm^2） in both years（2013 and 2014）. Lowering the irrigation amount significantly reduced evapotranspiration（ET）, but ET did not vary with different N rates（100–500 kg N/hm^2）. Both Y and B had robust linear relationships with ET, but the correlation between B and ET（R^2=0.8588） was much better than that between Y and ET（R^2=0.6062）. When ET increased, WP_（Y-ET） linearly increased and WP_（B-ET） decreased. Taking the indices of

关键词： water use efficiency water stress nitrogen use efficiency evapotranspiration water productivity for yield water productivity for biomass arid region