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基于改进YOLOv3-SPP算法的道路车辆检测
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作者 王涛 冯浩 +4 位作者 秘蓉新 李林 何振学 傅奕茗 吴姝 《通信学报》 EI CSCD 北大核心 2024年第2期68-78,共11页
针对在城市道路场景下视觉检测车辆时,车辆密集和远处车辆呈现小尺度,导致出现检测精度低或者漏检的问题,提出了一种基于改进的YOLOv3-SPP算法,对激活函数进行优化,以DIOU-NMS Loss作为边界框损失函数,增强网络的表达能力。为提高所提... 针对在城市道路场景下视觉检测车辆时,车辆密集和远处车辆呈现小尺度,导致出现检测精度低或者漏检的问题,提出了一种基于改进的YOLOv3-SPP算法,对激活函数进行优化,以DIOU-NMS Loss作为边界框损失函数,增强网络的表达能力。为提高所提算法对小目标和遮挡目标的特征提取能力,引入空洞卷积模块,增大目标的感受野。实验结果表明,所提算法在检测车辆目标时m AP提高了1.79%,也有效减少了在检测紧密车辆目标时出现的漏检现象。 展开更多
关键词 车辆检测 YOLOv3-spp算法 激活函数 空洞卷积 深度学习
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Genetic Diversity of Jute Mallow (Corchorus spp.) Accessions Based on ISSR Markers
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作者 Munguatosha Ngomuo Tsvetelina Stoilova +1 位作者 Tileye Feyissa Patrick A. Ndakidemi 《American Journal of Plant Sciences》 CAS 2024年第5期316-328,共13页
Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported.... Jute mallow is a nutritious leafy vegetable. The leaves are rich in proteins, vitamins and essential amino acids. Molecular characterization of Jute mallow with focus on improvement of leaf yield is scarcely reported. In the present study, inter sequence simple repeats (ISSR) molecular markers were employed to assess genetic diversity and relationships of 83 accessions of Jute mallow from different parts of Africa and Asia conserved at the World Vegetable Center East and Southern Africa. A total of 89 bands were amplified by 8 ISSR primers. Number of polymorphic bands per primer ranged from 2 to 6 with an average of 2.75 bands per primer. Polymorphic information content (PIC) values ranged from 0.390 to 0.760 with average of 0.53. Average Nei’s gene diversity (h) and Shannon’s information index (I) were 0.335 and 0.494 respectively. The highest pairwise genetic distance was 0.431 observed in a population from East Africa accessions. PC1 and PC2 axis explained 21.69% and 11.66% of the total variation respectively. UPGMA cluster analysis grouped the accessions into six main clusters at genetic similarity coefficient of 0.53 as standard value for classification. These results have important implications for jute mallow breeding and conservation. 展开更多
关键词 Corchorus spp. Genetic Diversity ISSRS Jute Mallow Leafy Vegetable
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E3 ubiquitin ligase PbrATL18 is a positive factor in pear resistance to drought and Colletotrichum fructicola infection
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作者 Likun Lin Qiming Chen +4 位作者 Kaili Yuan Caihua Xing Qinghai Qiao Xiaosan Huang Shaoling Zhang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期698-712,共15页
The Arabidopsis Toxicos en Levadura(ATL)protein is a subfamily of the E3 ubiquitin ligases,which exists widely in plants and is extensively involved in plant growth and development.Although the ATL family has been ide... The Arabidopsis Toxicos en Levadura(ATL)protein is a subfamily of the E3 ubiquitin ligases,which exists widely in plants and is extensively involved in plant growth and development.Although the ATL family has been identified in other species,such as Arabidopsis,Oryza sativa,and grapevine,few reports on pear ATL gene families have been reported.In this study,92 PbrATL genes were identified and analyzed from the Pyrus breschneideri genome.Motif analysis and phylogenetic tree generation divided them into nine subgroups,and chromosome localization analysis showed that the 92 PbrATL genes were distributed in 16 of 17 pear chromosomes.Transcriptome data and quantitative real-time polymerase chain reaction(qRT-PCR)experiments demonstrated that PbrATL18,PbrATL41,and PbrATL88 were involved in both pear drought resistance and Colletotrichum fructicola infection.In addition,Arabidopsis thaliana overexpressing PbrATL18 showed greater resistance to drought stress than the wild type(WT),and PbrATL18-silenced pear seedlings showed greater sensitivity to drought and C.fructicola infection than the controls.PbrATL18 regulated plant resistance by regulating chitinase(CHI),phenylalanine ammonia-lyase(PAL),polyphenol oxidase(PPO),catalase(CAT),peroxidase(POD),and superoxide dismutase(SOD)activities.This study provided a reference for further exploring the functions of the PbrATL gene in drought resistance and C.fructicola infection. 展开更多
关键词 PEAR colletotrichum fructicola Arabidopsis Toxicos en Levadura(ATL) Drought stress
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Early Detection of Colletotrichum Kahawae Disease in Coffee Cherry Based on Computer Vision Techniques
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作者 Raveena Selvanarayanan Surendran Rajendran Youseef Alotaibi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期759-782,共24页
Colletotrichum kahawae(Coffee Berry Disease)spreads through spores that can be carried by wind,rain,and insects affecting coffee plantations,and causes 80%yield losses and poor-quality coffee beans.The deadly disease ... Colletotrichum kahawae(Coffee Berry Disease)spreads through spores that can be carried by wind,rain,and insects affecting coffee plantations,and causes 80%yield losses and poor-quality coffee beans.The deadly disease is hard to control because wind,rain,and insects carry spores.Colombian researchers utilized a deep learning system to identify CBD in coffee cherries at three growth stages and classify photographs of infected and uninfected cherries with 93%accuracy using a random forest method.If the dataset is too small and noisy,the algorithm may not learn data patterns and generate accurate predictions.To overcome the existing challenge,early detection of Colletotrichum Kahawae disease in coffee cherries requires automated processes,prompt recognition,and accurate classifications.The proposed methodology selects CBD image datasets through four different stages for training and testing.XGBoost to train a model on datasets of coffee berries,with each image labeled as healthy or diseased.Once themodel is trained,SHAP algorithmto figure out which features were essential formaking predictions with the proposed model.Some of these characteristics were the cherry’s colour,whether it had spots or other damage,and how big the Lesions were.Virtual inception is important for classification to virtualize the relationship between the colour of the berry is correlated with the presence of disease.To evaluate themodel’s performance andmitigate excess fitting,a 10-fold cross-validation approach is employed.This involves partitioning the dataset into ten subsets,training the model on each subset,and evaluating its performance.In comparison to other contemporary methodologies,the model put forth achieved an accuracy of 98.56%. 展开更多
关键词 Computer vision coffee berry disease colletotrichum kahawae XG boost shapley additive explanations
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Strawberry (Fragaria spp.): Cultivation, Production, Consumption, and Marketing in Cameroon
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作者 Djeuani Astride Carole Moutamal Djem Rose Theophine Derricka +21 位作者 Mbouobda Hermann Désiré Abdoulaye Souaibou Meliga Essimi Célestine Bouopda Nono Joël Anafack Donasson Dioril Messouang Bernard Didier Ndongo III Boris Charlen Kaffo Emmanuel Kamga Fossouo Anselme Xavier Tiki Antoine Marie Kevin Nyimiebolo Bengono Audrey Maguy Manuela Diobe Motassy Adounga Samuel Brice Amama Amama Benjamin Nshanji Jones Panguepko Fendju Christophe Nzie Oussena Nguetrapouna Issofa Mpon Ikoyin Linda NKouéya Christelle Ladone Amang Amang A. Ziem Niemenak Nicolas 《Agricultural Sciences》 2024年第4期449-471,共23页
Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms ... Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas. 展开更多
关键词 Fragaria spp. Cultivation Technique Attack of Pathogens Annual Production Cameroon
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Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso
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作者 Stéphanie Lynseh Carine Sita Bénao Dabiré Amana Métuor +7 位作者 Abdoul Karim Ouattara Rahimatou Yasmine Wendkouni Tiemtoré Nicolas Ouédraogo Blandine Ouédraogo Rhaina Olivia Badini Lionel Eliada Benoit Bambara Serge Sougué Jacques Simporé 《Open Journal of Applied Sciences》 2024年第4期881-892,共12页
Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales site... Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections. 展开更多
关键词 MULTIDRUG-RESISTANT CHICKEN OUAGADOUGOU Escherichia coli Salmonella spp. Antibiotic
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基于SPPs的二维多凹槽结构MIM波导透射特性的研究
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作者 胡月 陈春梅 孙文汇 《科技与创新》 2024年第9期40-42,共3页
不规则结构对波导的传播特性有着很大的影响,但对于MIM(Metal-Insulator-Metal,金属-介质-金属型)波导双边矩形槽并添加多凹槽结构对传播特性的影响方面的研究尚少。在研究内嵌凹槽位置对MIM波导透射特性影响的基础上,提出了在双矩形波... 不规则结构对波导的传播特性有着很大的影响,但对于MIM(Metal-Insulator-Metal,金属-介质-金属型)波导双边矩形槽并添加多凹槽结构对传播特性的影响方面的研究尚少。在研究内嵌凹槽位置对MIM波导透射特性影响的基础上,提出了在双矩形波导模型基础的内部添加多凹槽结构来影响波导的透射特性,并对波长与透射的关系及不同凹槽位置、不同凹槽数目的电场模图进行了对比分析。在凹槽位置改变时,Fano共振峰位置发生了移动,在小波长区域共振峰的数目也有所改变。随着上凹槽位置的增大,最大透射峰位置发生了蓝移,透射强度也有一定的增强;增加凹槽对数,得到波长与透射特性的关系曲线发生了改变,随着凹槽对数的增加,Fano共振峰的位置发生了一定的红移,且在小波长600~1 000 nm区域,Fano共振峰数目及透射峰值均发生了变化。这些研究结果可为预测金属缝隙波导制备过程中小尺度、多凹槽局部缺陷结构对其传播特性的影响提供理论依据。 展开更多
关键词 sppS 异常透射 MIM波导 透射特性
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一种山茶刺盘孢Colletotrichum camelliae实时荧光定量PCR快速检测方法的建立
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作者 张晓阳 程淑媛 +11 位作者 蒋军喜 陈艳 黄纪刚 刘爽 刘克东 邱慧芳 江武 叶茵 袁倩 余玉华 单崇蕾 刘家鑫 《生物灾害科学》 2024年第1期134-141,共8页
【目的】建立一种快速检测茶树炭疽病病原菌山茶刺盘孢(Colletotrichumcamelliae)的实时荧光定量PCR检测方法。【方法】以茶树炭疽病病原菌山茶刺盘孢(C. camelliae)为检测目标,根据刺盘孢属ApMat基因片段设计特异性引物,建立q PCR检测... 【目的】建立一种快速检测茶树炭疽病病原菌山茶刺盘孢(Colletotrichumcamelliae)的实时荧光定量PCR检测方法。【方法】以茶树炭疽病病原菌山茶刺盘孢(C. camelliae)为检测目标,根据刺盘孢属ApMat基因片段设计特异性引物,建立q PCR检测技术体系,验证引物特异性,测试反应的灵敏度,绘制标准曲线,并采集田间病叶测试检测效果。【结果】设计的四组引物对中,引物对CcF/CcR特异性最好,扩增效率最高;用于定量检测C. camelliae的灵敏度为10 pg/μL,DNA浓度的对数(X)与Ct值(Y)之间的线性关系为Y=-3.529 6X+36.938(R^(2)=0.9957,E=92.01);该体系检测C.camelliae溶解曲线对应的特异峰值Tm为(85.5±0.5)℃;用该体系在人工接种C. camelliae的病斑组织和田间病叶中检测到了C. camelliae的存在。【结论】建立的q PCR反应体系可特异性定量检测C. camelliae,并可应用于田间病害的早期诊断。 展开更多
关键词 茶炭疽病 山茶刺盘孢 实时荧光定量PCR 快速检测
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葡萄炭疽病菌(Colletotrichum spp.)种群对多菌灵的抗药性监测 被引量:7
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作者 杨敬辉 许媛 +3 位作者 肖婷 褚姝频 芮东明 姚克兵 《果树学报》 CAS CSCD 北大核心 2021年第2期242-249,共8页
【目的】阐明江苏丘陵地区葡萄炭疽病菌(Colletotrichum spp.)种群(GG)对多菌灵的抗药性流行动态及抗性分子机制。【方法】采用区分剂量法和菌丝生长速率法分别测定GG的抗药性流行动态和敏感性;田间人工接种GG后再检测回分离菌株对药剂... 【目的】阐明江苏丘陵地区葡萄炭疽病菌(Colletotrichum spp.)种群(GG)对多菌灵的抗药性流行动态及抗性分子机制。【方法】采用区分剂量法和菌丝生长速率法分别测定GG的抗药性流行动态和敏感性;田间人工接种GG后再检测回分离菌株对药剂敏感性的方法评价GG的抗药性流行演化;药剂作用标靶基因序列分析阐明抗性分子机制。【结果】2013年和2017年GG对多菌灵的EC50均值(ρ)分别为0.528 5 mg·L-1和7.787 8 mg·L^-1。GG对多菌灵的抗性菌株比率从2013年的2.34%上升至2017年的32.21%。2017年和2018年多菌灵接种抗性菌株处理的防效分别为0.64%和4.18%。回分离GG中抗性菌株/敏感菌株的比率2017年和2018年分别为65.00%和68.18%,均高于接种比率50%。抗性菌株靶标基因(TUB2)第198位的谷氨酸突变成丙氨酸(E198A),或第200位的苯丙氨酸突变成络氨酸(F200Y)。【结论】江苏丘陵地区GG对多菌灵已形成抗药性流行。多菌灵持续施用是GG田间抗药性流行的驱动因子。GG抗性菌株标靶基因突变类型为E198A或F200Y。 展开更多
关键词 葡萄 炭疽病菌 多菌灵 抗药性监测 分子机制
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水葫芦生防炭疽菌(Colletotrichum spp.)的分离与生物学性状 被引量:7
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作者 丁义 顾振芳 +2 位作者 吴辉辉 庄奇佳 褚建君 《上海交通大学学报(农业科学版)》 2006年第1期13-19,共7页
本文研究了光照、温度、pH、湿度和介质对水葫芦生防真菌炭疽菌(Colletotrichum spp.)生长、产孢和分生孢子萌发的影响。结果表明全黑暗和光暗交替处理有利于该菌菌丝的生长和孢子萌发;光照处理对产孢量无显著影响。该菌菌丝生长、产孢... 本文研究了光照、温度、pH、湿度和介质对水葫芦生防真菌炭疽菌(Colletotrichum spp.)生长、产孢和分生孢子萌发的影响。结果表明全黑暗和光暗交替处理有利于该菌菌丝的生长和孢子萌发;光照处理对产孢量无显著影响。该菌菌丝生长、产孢和孢子萌发的温度范围为5 ̄35℃;菌丝生长、产孢最适温度25℃;孢子萌发最适温度35℃。该菌生长和产孢的pH范围为5.0 ̄9.5;最适生长pH为5.6 ̄6.0;最适产孢pH6.6、7.5;孢子萌发的pH范围为3.6 ̄8.0,最适pH5.0、6.6。在相对湿度为75% ̄100%和水滴中,孢子均可萌发,最适湿度90% ̄100%。玉米粉、1%蛋白胨等介质对孢子萌发有促进作用。 展开更多
关键词 水葫芦 生物防治 炭疽菌 生物学性状
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智能手机BDS-3/GPS数据质量及SPP性能分析 被引量:1
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作者 王瑞光 王中元 +2 位作者 胡超 王阳阳 刘冰雨 《大地测量与地球动力学》 CSCD 北大核心 2023年第2期168-172,共5页
使用可观测到BDS-3 B1I/B1C/B2a频率和GPS L1/L5频率的智能手机Xiaomi 11(青春版)作为研究对象,分别进行静态实验和不同场地的动态实验,分析手机输出的三频BDS和双频GPS原始观测数据质量及单频SPP性能。实验结果表明,智能手机的GNSS天... 使用可观测到BDS-3 B1I/B1C/B2a频率和GPS L1/L5频率的智能手机Xiaomi 11(青春版)作为研究对象,分别进行静态实验和不同场地的动态实验,分析手机输出的三频BDS和双频GPS原始观测数据质量及单频SPP性能。实验结果表明,智能手机的GNSS天线成本低致使其信号质量不佳,其中GPS L1频率和BDS B1C频率抗干扰性较强:BDS B1C频率定位结果在静态和动态实验中均较为稳定;GPS L1频率定位结果在动态实验中优于GPS L5频率,在静态实验中略差于GPS L5频率。 展开更多
关键词 Android智能手机 单频spp BDS-3 GPS 数据质量分析
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辣椒炭疽病菌Colletotrichum nigrum鉴定、生物学特性及药剂敏感性研究 被引量:2
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作者 陈鹏宇 杨立辉 +4 位作者 翟长兰 田慧迪 张敏 白庆荣 赵廷昌 《中国瓜菜》 CAS 北大核心 2023年第3期27-35,共9页
对2021年9—10月从吉林省和内蒙古自治区东部辣椒主产区采集的辣椒果实炭疽病样本进行病菌的组织分离和纯化,获得212株形态特征基本一致的菌株,对代表菌株进行柯氏验证,证明其具有致病性,为该病害的病原菌。结果表明,结合病原菌的形态... 对2021年9—10月从吉林省和内蒙古自治区东部辣椒主产区采集的辣椒果实炭疽病样本进行病菌的组织分离和纯化,获得212株形态特征基本一致的菌株,对代表菌株进行柯氏验证,证明其具有致病性,为该病害的病原菌。结果表明,结合病原菌的形态学特征及基于ITS、TUB2、ACT、GAPDH和CHS-1基因序列构建系统发育树,确定病原菌为Colletotrichum nigrum。病原菌的生物学特性研究发现,OA培养基适合病原菌菌丝生长;D-麦芽糖是最佳碳源;蛋白胨为最佳氮源;最佳pH为10;最适培养温度为20℃;全黑暗时最适合菌丝生长。代表菌株对25种杀菌剂敏感性研究表明,400 g·L^(-1)氯氟醚·吡唑酯SC、240 g·L^(-1)氯氟醚·吡唑酯EC、42.4%唑醚·氟酰胺SC、40%唑醚·戊唑醇SC、43%唑醚·氟酰胺SC对病菌菌丝生长速率和孢子萌发均有明显抑制作用,其EC_(50)<1 mg·L^(-1),可作为该病害防治的优选药剂。 展开更多
关键词 辣椒炭疽病 colletotrichum nigrum 病原鉴定 生物学特性 药剂敏感性
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鸭SPP1基因的生物信息学分析、原核表达及其在鸭胚胎期骨骼肌中表达规律研究 被引量:1
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作者 曹敞 职卓 +6 位作者 蔡瑛婕 李雨笑 张纪桥 张淑雅 刘小林 胡志刚 张建勤 《中国畜牧杂志》 CAS CSCD 北大核心 2023年第7期147-154,共8页
分泌型焦磷酸蛋白1(SPP1)是一种具有多种功能的分泌型酸性糖蛋白,在肌肉发育过程中具有重要的调控作用,但SPP1基因在鸭骨骼肌中的结构和功能尚不明确。本研究选择胚胎期第17天(E17 d)、第21天(E21 d)、第24(E24 d)和第27天(E27 d)北京... 分泌型焦磷酸蛋白1(SPP1)是一种具有多种功能的分泌型酸性糖蛋白,在肌肉发育过程中具有重要的调控作用,但SPP1基因在鸭骨骼肌中的结构和功能尚不明确。本研究选择胚胎期第17天(E17 d)、第21天(E21 d)、第24(E24 d)和第27天(E27 d)北京鸭和汉中麻鸭胸肌及腿肌组织作为实验材料,克隆了SPP1基因的CDS区序列并对该序列进行分析,进一步诱导基因表达,采用SDS-PAGE检测表达蛋白。同时采用qPCR方法分析SPP1基因在胚胎期北京鸭与汉中麻鸭胸肌和腿肌组织中的相对表达。结果表明:SPP1基因开放阅读框大小为915 bp,编码304个氨基酸,是有SP型信号肽的亲水性不稳定蛋白,无跨膜结构,有磷酸化和糖基化位点。qPCR结果表明,北京鸭骨骼肌SPP1的表达量在E27 d达到最高;而汉中麻鸭胸肌SPP1在E17 d的表达量最高,在E21 d的腿肌中表达量最高。在胚胎期北京鸭与汉中麻鸭骨骼肌的比较中,汉中麻鸭胸肌SPP1基因在E17 d时的表达量显著高于北京鸭,而在E27 d则低于北京鸭。北京鸭腿肌SPP1在E17 d和E27 d的表达量均高于汉中麻鸭,而在E21 d和E24 d则均低于汉中麻鸭。本研究揭示了鸭SPP1基因的结构及该基因在北京鸭和汉中麻鸭骨骼肌中的表达规律,为鸭生长发育的调控机制研究提供一定的参考。 展开更多
关键词 spp1 骨骼肌 原核表达 生物信息学分析 表达规律
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城市复杂环境下不同加权模型对动态SPP定位性能影响分析 被引量:2
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作者 付红波 《测绘通报》 CSCD 北大核心 2023年第3期139-143,共5页
城市复杂环境下,由于建筑物的遮挡,卫星定位严重受到非视距信号的影响。测量值随机误差加权模型是卫星定位的关键环节,它能够合理地分配各卫星在解算中所起作用的大小。因此,加权模型常用于缓解非视距信号对卫星定位的影响。本文针对目... 城市复杂环境下,由于建筑物的遮挡,卫星定位严重受到非视距信号的影响。测量值随机误差加权模型是卫星定位的关键环节,它能够合理地分配各卫星在解算中所起作用的大小。因此,加权模型常用于缓解非视距信号对卫星定位的影响。本文针对目前主流的多种加权模型进行了系统总结和阐述,比较和分析了城市复杂环境下不同加权模型对卫星动态单点定位的影响。试验结果表明,各加权模型均能够在一定程度上提高定位精度,其中综合加权模型具有最优的性能表现。 展开更多
关键词 城市复杂环境 非视距信号 加权模型 动态spp
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根际溶磷伯克霍尔德菌Paraburkholderia spp.对马尾松苗的促生作用 被引量:3
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作者 徐红云 吕俊 于存 《生物技术通报》 CAS CSCD 北大核心 2023年第6期274-285,共12页
为筛选溶磷效果较好的根际细菌(phosphate-solubilizing rhizobacteria,PSB),并明确其对马尾松苗的促生效果和作用机制。利用土壤稀释平板法进行PSB菌株的分离和纯化,通过形态学和16S rDNA分子测序等方法进行PSB菌株的鉴定,最后将PSB菌... 为筛选溶磷效果较好的根际细菌(phosphate-solubilizing rhizobacteria,PSB),并明确其对马尾松苗的促生效果和作用机制。利用土壤稀释平板法进行PSB菌株的分离和纯化,通过形态学和16S rDNA分子测序等方法进行PSB菌株的鉴定,最后将PSB菌株接种至马尾松苗,培养60 d后测定马尾松苗生长、生理、苗根际土壤理化性质和根际细菌群落结构和组成。结果表明:由马尾松根际土中分离获得溶磷能力较强的3个PSB菌株WJ10、WJ25和WJ41均为伯克霍尔德菌Paraburkholderia spp.;3个PSB菌株对磷酸铝的增溶能力最强,其次是磷酸三钙、磷酸氢钙和磷酸铁;盆栽试验表明,3个PSB菌株均可促进幼苗的生长,其中WJ25对苗高、根长的促进效果最明显,WJ41和WJ10次之。3个PSB菌株对苗促生的主要机制包括,PSB提高了马尾松苗的根系活力、叶绿素b、可溶性蛋白等生长指标及氮、磷和钾等养分含量;同时,提升了根际土有效磷、速效钾、活性氮、土壤养分含量、土壤酶活性;此外,3个PSB菌株的添加还影响了马尾松苗根际细菌群落的组成和多样性,促进了Bacillus、Nitrosospira、Gemmata和Cytophaga等有益菌在根际土壤中的显著富集。综上,本研究筛选获得的3个溶磷伯克霍尔德菌,它们能够通过调控植物生理及改变根际微环境从而促进马尾松苗的生长。通过本研究,为马尾松根际溶磷细菌菌肥的开发和应用提供了理论依据。 展开更多
关键词 根际溶磷细菌 促生 伯克霍尔德菌 马尾松 根际微生物
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Resistance risk and molecular mechanism associated with resistance to picoxystrobin in Colletotrichum truncatum and Colletotrichum gloeosporioides 被引量:1
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作者 SHI Niu-niu LIAN Jin-pan +2 位作者 QIU De-zhu CHEN Fu-ru DU Yi-xin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第12期3681-3693,共13页
Anthracnose,caused by Colletotrichum truncatum and C.gloeosporioides,is amongst the most serious diseases of soybean in China.Picoxystrobin,a quinone outside inhibitor fungicide,is commonly used for the control of ant... Anthracnose,caused by Colletotrichum truncatum and C.gloeosporioides,is amongst the most serious diseases of soybean in China.Picoxystrobin,a quinone outside inhibitor fungicide,is commonly used for the control of anthracnose.Its resistance risk and mechanism in C.truncatum and C.gloeosporioides are unclear.In this study,the sensitivities of 128 C.truncatum and 121 C.gloeosporioides isolates to picoxystrobin were investigated,and unimodal distributions were observed with average EC_(50)values of 0.7740 and 1.1561μg mL^(-1),respectively.Eleven picoxystrobin-resistant mutants of C.truncatum and six mutants of C.gloeosporioides were acquired,with EC_(50)values varying from 5.40-152.96 and 13.53-28.30μg mL^(-1),respectively.Compared to the parental isolates,mutants showed similar or higher relative fitness in conidial production and germination,and pathogenicity.Collectively,the resistance risk of C.truncatum and C.gloeosporioides to picoxystrobin is moderate to high.There was positive cross-resistance between picoxystrobin and pyraclostrobin,but not between picoxystrobin and fluazinam,difenoconazole,or propiconazole.The G143S mutation in Cyt b protein was detected in seven high-resistant mutants of C.truncatum(RF>100),and G137R occurred in four moderate-resistant mutants(RF<_(50)).Contrastingly,there were no point mutations in Cyt b of any C.gloeosporioides mutants.Molecular docking confirmed that two mutations conferred different resistance levels to picoxystrobin.Under greenhouse trials,picoxystrobin did not control mutants with the G143S mutation,those bearing G137R or no point mutation were somewhat controlled,but at a lower level compared to wild-type isolates.These results showed that integrated management strategies should be implemented to preserve fungicide effectiveness. 展开更多
关键词 colletotrichum truncatum colletotrichum gloeosporioides picoxystrobin point mutation Cyt b molecular docking
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基于YOLOv3-spp的汽车轮毂表面缺陷检测算法研究与分析 被引量:2
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作者 张震宇 刘阳 刘福才 《计量学报》 CSCD 北大核心 2023年第9期1375-1382,共8页
针对传统人工检测方法效率低且准确率不高等问题,提出一种基于YOLOv3-spp网络的自动缺陷检测方法。首先通过图像切片提取缺陷区域,然后将提取的缺陷图片经过数据增强后组成数据集并以此训练YOLOv3-spp网络,接着对比分析了不同深度学习... 针对传统人工检测方法效率低且准确率不高等问题,提出一种基于YOLOv3-spp网络的自动缺陷检测方法。首先通过图像切片提取缺陷区域,然后将提取的缺陷图片经过数据增强后组成数据集并以此训练YOLOv3-spp网络,接着对比分析了不同深度学习网络及数据集筛选方法对轮毂表面缺陷的检测效果。实验结果表明:在工业现场采集的数据集上,训练好的YOLOv3-spp神经网络可以准确地定位,并识别出点状、线性、油泥油漆、针孔4类缺陷,其平均准确率分别为84.5%、93.4%、95.4%和89.5%,检测速度达到35 ms/幅,满足检测的实时性要求,且检测准确率优于Faster R-CNN和SSD两种常用神经网络。 展开更多
关键词 计量学 表面缺陷检测 汽车轮毂 机器视觉 深度学习 YOLOv3-spp 平均准确率
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RTKLIB(b34)SPP数据处理解析
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作者 胡小华 刘长建 《测绘与空间地理信息》 2023年第2期52-56,共5页
伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功... 伪距单点定位(Pseudo-range Single Point Positioning,SPP)应用较早且广泛。随着GNSS相关技术的不断进步,伪距观测值与广播星历的精度也在不断提高,多GNSS系统还带来了更多的伪距观测值,SPP依然值得关注。RTKLIB作为一款广为接受的多功能GNSS数据处理开源软件,是实现二次开发的良好平台,为此,本文对新版本RTKLIB(b34)SPP数据处理进行了解析,给出了其处理流程,分析了其平差求解、结果检验、异常检测的原理,指出了其优缺点,为今后借鉴或改进提供了参考。 展开更多
关键词 RTKLIB(b34) spp 处理流程 原理分析
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基于YOLOv3-SPP的遥感图像目标检测压缩模型
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作者 齐保贵 赵鹏赫 +2 位作者 陈禾 陈亮 龙腾 《信号处理》 CSCD 北大核心 2023年第9期1621-1632,共12页
近年来,卷积神经网络模型已被广泛应用于遥感图像目标检测任务中,但自然场景图像与遥感图像的目标特性存在差异,针对自然场景设计的模型往往难以在遥感图像任务中取得良好的效果。同时,很多遥感图像处理任务需要在星载、机载等资源有限... 近年来,卷积神经网络模型已被广泛应用于遥感图像目标检测任务中,但自然场景图像与遥感图像的目标特性存在差异,针对自然场景设计的模型往往难以在遥感图像任务中取得良好的效果。同时,很多遥感图像处理任务需要在星载、机载等资源有限的平台中进行,难以部署参数量、计算量大的复杂模型。针对以上问题,本文对在自然场景中性能优异的YOLOv3-SPP模型进行适应性改进及参数压缩。首先,对原始的L1范数剪枝算法进行改进,提出基于L1范数和均值差的加权剪枝算法,能够更好地保留重要的通道。其次,对剪枝后的子网集合进行快速评估,选取评估结果最好的子网进行微调。在预训练和微调阶段,本文将SPP模块中的最大池化层替换为softmax加权池化层,着重突出深层网络中权重较大的特征,提高了模型的检测精度。本文在多个公开遥感数据集上进行实验,结果表明改进的YOLOv3-SPP模型在遥感目标检测任务上具有更好的性能,同时本文的剪枝算法可以在相同的参数压缩比例条件下,降低模型的性能损失。 展开更多
关键词 目标检测 YOLOv3-spp 遥感 模型压缩
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改进YOLOv3-SPP水下目标检测研究 被引量:7
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作者 叶赵兵 段先华 赵楚 《计算机工程与应用》 CSCD 北大核心 2023年第6期231-240,共10页
针对水下目标检测任务中图像模糊、背景复杂以及目标小而导致误检和漏检问题,提出一种改进YOLOv3-SPP的水下目标检测算法。利用UWGAN网络对水下原始图像进行恢复,采用Mixup方法增强数据,减少错误标签记忆;以YOLOv3-SPP网络结构为基础,... 针对水下目标检测任务中图像模糊、背景复杂以及目标小而导致误检和漏检问题,提出一种改进YOLOv3-SPP的水下目标检测算法。利用UWGAN网络对水下原始图像进行恢复,采用Mixup方法增强数据,减少错误标签记忆;以YOLOv3-SPP网络结构为基础,增加网络预测尺度,提高小目标检测性能;引入CIoU边框回归损失,提高定位精度;利用K-Means++聚类算法,筛选最佳Anchor box。将改进YOLOv3-SPP算法在处理后的URPC数据集上进行实验,平均检测精度由79.58%提升到88.71%,速度为28.9FPS。结果表明,改进算法综合检测能力优于其他算法。 展开更多
关键词 水下目标 图像增强 YOLOv3-spp UWGAN CIoU K-Means++
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