The mitogen-activated protein kinase(MAPK)cascade is crucial to plant growth,development,and stress responses.MAPK kinases(MAPKK)play a vital role in linking upstream MAPKK kinases(MAPKKK)with the downstream MAPK.Blac...The mitogen-activated protein kinase(MAPK)cascade is crucial to plant growth,development,and stress responses.MAPK kinases(MAPKK)play a vital role in linking upstream MAPKK kinases(MAPKKK)with the downstream MAPK.Black spot is one of the most serious fungal diseases of pear which is an important part of the fruit industry in China.The MAPKK genes have been identified in many plants,however,none has been reported in pear(Pyrus bretschneideri).In order to explore whether MAPK gene of pear is related to black spot disease,we designed this experiment.The present study investigated eight putative PbrMAPKK genes obtained from the Chinese white pear genome.The phylogenetic analysis revealed that PbrMAPKK genes were divided into A,B,C,and D groups.These PbrMAPKK genes are randomly distributed on 7 out of 17 chromosomes and mainly originated from the whole-genome duplication(WGD)event.The expression analysis of PbrMAPKK genes in seven pear tissues and the leaves of susceptible and resistant varieties after Alternaria alternata infection by quantitative real-time PCR(qRT-PCR)identified seven candidate genes associated with resistance.Furthermore,virus-induced gene silencing(VIGS)indicated that PbrMAPKK6 gene enhanced resistance to pear black spot disease in pear.展开更多
This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The ...This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The aim was to provide stakeholders with information that will aid their understanding of accident prone locations and accessible rescue possibilities for accident victims on the roads in FCT. GPS Map 76S Mark (GARMIN) was used to locate and pick coordinates of data in the study area. A total of 16 possible emergency health care facilities, seventy (70) RTC black spots and Five Zebra point locations were obtained from FRSC. ArcGIS 10.0 was used to compute the data by plotting the coordinates to produce maps of the spatial relationship and to carry out Nearest Neighbour Analysis (NNA). The result was further used to determine the spatial patterns of RTC black spots as well as patterns of the emergency facilities. Generally, the result shows that the spatial trend is turning towards dispersion. However, there is less than 1% likelihood that the dispersed patterns could be the result of random chance. It was recommended that, the Federal Road Safety Commission should be staffed with trained professionals that can be responsible for accident data surveillance and analysis using geospatial techniques.展开更多
[Objective]The aim was to isolate and identify the pathogen causing black spot disease in guava(Psidium guajava),so as to determine its taxonomic status.[Method]The fungus was identified by determining its pathogeni...[Objective]The aim was to isolate and identify the pathogen causing black spot disease in guava(Psidium guajava),so as to determine its taxonomic status.[Method]The fungus was identified by determining its pathogenicity,observing its morphology characteristics and analyzing its ITS sequence.[Result]The pathogen causing black spot disease in guava was a strain of Guignardia mangiferae.[Conclusion]This study will provide theoretical basis for curing black spot disease of guava.展开更多
[Objective] Disease analysis and pathogen identification of black spot disease of Chinese cabbage [Alternaria brassicae(Berk.) Sace.] in Bijie City of Guizhou Province was carried out,so as to raise the correspondin...[Objective] Disease analysis and pathogen identification of black spot disease of Chinese cabbage [Alternaria brassicae(Berk.) Sace.] in Bijie City of Guizhou Province was carried out,so as to raise the corresponding prevention measures.[Method] Pathogen was isolated from diseased leaves using tissue surface separation method for cultivation,microscopic examination,spore size determination and pathogen identification.[Result] Microscopic examination showed that the disease was caused by Alternaria sp.,the size of its spores was(15.0-38.5) μm×(7.5-13.5) μm.Combining with the characteristics of host and pathogen,the pathogen caused black spot disease of Chinese cabbage was identified to be Alternaria brassicicola.[Conclusion] A.brassicicola was the pathogenic fungi of black spot disease of Chinese cabbage in Bijie City of Guizhou Province,and damage caused by the disease could be reduced through agricultural measures and chemical control.展开更多
柑橘黑斑病(Citrus Black Spot,CBS)主要危害果实,在果皮上形成各种病斑而影响果实的外观品质和销售价格,严重时可造成田间落果和贮藏期果实腐烂。同时,黑斑病被欧盟列为A1类外来有害生物,美国对此也有严格的限制。因此,该病害影响柑橘...柑橘黑斑病(Citrus Black Spot,CBS)主要危害果实,在果皮上形成各种病斑而影响果实的外观品质和销售价格,严重时可造成田间落果和贮藏期果实腐烂。同时,黑斑病被欧盟列为A1类外来有害生物,美国对此也有严格的限制。因此,该病害影响柑橘鲜果的国际贸易。黑斑病的病原属球座菌(Guignardia),其无性态为叶点霉菌(Phyl-losticta)。宽皮柑橘(Citrus reticulata)、橙类(C.sinensis)和柠檬(C.limon)上为柑橘球座菌(G.citricarpa),无性态为柑橘叶点霉(P.citricarpa)。而最新研究表明亚洲柚黑斑病(也称tan spot,棕褐斑病)的病原与上述柑橘上的不同,其有性态尚未发现,无性态则为亚洲柑橘叶点霉菌(P.citriasiana)。此外,P.capitalensis作为一种内生菌普遍存在于各类柑橘中,常干扰病害的检测。鉴于该病害在我国发生普遍,局部危害严重,而相关信息匮乏,作者综合国内外相关研究报道,结合自身部分工作,就病害发生历史、分布和危害性,病害症状,病原菌种类,发生规律和检测,病害在欧盟国家的发生风险,以及病害的防治等方面作了较为详细的介绍,以期满足读者对柑橘黑斑病的全方位了解需求。展开更多
Taking tumorous stem mustard infected by black spot disease as the research material, the ribosomal 5.8S rDNA and its flanking ITS region were cloned, sequenced and aligned in the study. The results showed that the ba...Taking tumorous stem mustard infected by black spot disease as the research material, the ribosomal 5.8S rDNA and its flanking ITS region were cloned, sequenced and aligned in the study. The results showed that the base sequence of pathogens collected from five different sites was almost identical with that of Alternaria brassicae, and the similarity degree reached 99.68%, without base difference greater than 3 bp. It had obvious differences with the sequences of A. brassicicola and A. japonica, and the base difference was greater than 3 bp with a lot of fragment deletions. It was preliminarily determined that the pathogen cau- sing black spot disease on tumorous stem mustard was A. brassicae.展开更多
In this study,the factors affecting the formation of small black spot defects on the surface of a hot-dip galvanized pure zinc strip are analyzed. These defects are primarily formed w hen the iron-aluminum inhibition ...In this study,the factors affecting the formation of small black spot defects on the surface of a hot-dip galvanized pure zinc strip are analyzed. These defects are primarily formed w hen the iron-aluminum inhibition layer is incompletely formed or fails to form or when foreign matter adheres to the surface or embeds in the zinc layer.The defects can be reduced by controlling the cleanliness and activity of the strip base before coating,regulating the zinc pot process parameters,and ensuring the cleanliness of the passline and workshop.展开更多
Marigold ( Tagetes erecta) originated in South America is the main raw material of lutein, which plays a vital role in treating maeula lutea retinae, im- proving immunity and delaying aging. Black spot is the main d...Marigold ( Tagetes erecta) originated in South America is the main raw material of lutein, which plays a vital role in treating maeula lutea retinae, im- proving immunity and delaying aging. Black spot is the main disease reducing marigold production. This paper concluded occurrence and damage of black spot, the species and symptoms of pathogens, pathogenic factors, selection of disease-resistant varieties and effective means against black spot, and made a briefly analysis of the existing problems and the corresponding solutions, in order to provide a theoretical basis for disease-resistant breeding of marigold.展开更多
In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is close...In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is closely related to plant residues,rainfall,cultivation conditions and varieties.On the basis of understanding the symptoms and occurrence regularity of Chinese rose black spot,combination measures of agricultural and chemical prevention and control should be taken.展开更多
In general, the location of traffic accidents is described as an address with text, so they are difficult to display on the map. The paper discusses how to utilize the geocoding technology and VRS-GPS positioning tech...In general, the location of traffic accidents is described as an address with text, so they are difficult to display on the map. The paper discusses how to utilize the geocoding technology and VRS-GPS positioning technology to record the traffic accidents with Geo-spatial information. Based on the spatial relationship between traffic accidents and road network elements, two-way association relationship is defined by spatial relationship computation. Then the paper presents the method which takes the potential of reducing accidents as an index to extract the black spots. Finally, in the discussion, the association relationship between black spots and traffic attributes is used to analyze the factors that resulting in traffic accidents.展开更多
This paper describes the development of a hyperspectral imaging approach for identifying fruits infected with citrus black spot(CBS).Hyperspectral images were taken of healthy fruit and those with CBS symptoms or othe...This paper describes the development of a hyperspectral imaging approach for identifying fruits infected with citrus black spot(CBS).Hyperspectral images were taken of healthy fruit and those with CBS symptoms or other potentially confounding peel conditions such as greasy spot,wind scar,or melanose.Spectral angle mapper(SAM)and spectral information divergence(SID)hyperspectral analysis approaches were used to classify fruit samples into two classes:CBS or non-CBS.The classification accuracy for CBS with SAM approach was 97.90%,and 97.14% with SID.The combination of hyperspectral images and two classification approaches(SID and SAM)have proven to be effective in recognizing CBS in the presence of other potentially confounding fruit peel conditions.The study result can be a reference for the non-destructive detection of fruits infected with citrus black spot.展开更多
The identification of accident black spots is of great significance for the prevention of traffic accidents.Commonly used accident black spot identification methods divide road sections for the analysis of accident da...The identification of accident black spots is of great significance for the prevention of traffic accidents.Commonly used accident black spot identification methods divide road sections for the analysis of accident data,the direct result of which is the splitting of accident black spots,which affects the results.This paper is based on three years of traffic accident data from the Beijing-Harbin Expressway,including the time and location of traffic accidents,form of the accident fatalities,severe injuries,slight injuries,and property damage only(PDO).To avoid road division effects,an identification method based on the accident spacing distribution is established by using quality control theory.The results show that the average number of accidents per kilometer by the method proposed in this paper is 42,which is much higher than 10,identified by other identification methods.The method proposed in this paper improves the accuracy of the identification results.This method avoids the problem of road segmentation found in other common methods and can more accurately reflect the spatial distribution of traffic accidents.Thus making the identification of accidents more scientific and accurate.展开更多
The damage characteristics and occurrence regularity of radish alternaria leaf spot, black rot, soft rot, virus disease and hollowness are introduced in the paper, and the corresponding control method is proposed from...The damage characteristics and occurrence regularity of radish alternaria leaf spot, black rot, soft rot, virus disease and hollowness are introduced in the paper, and the corresponding control method is proposed from two aspects of agricultural control and chemical control.展开更多
Taking the research papers on black peanut in National Knowledge Infrastructure(CNKI)as data sources,we determine the research hot spots on black peanut using word frequency analysis,and analyze the main research dire...Taking the research papers on black peanut in National Knowledge Infrastructure(CNKI)as data sources,we determine the research hot spots on black peanut using word frequency analysis,and analyze the main research directions that change over the years.The results show that the relevant researches on black peanut are mainly concentrated in six themes(study of varieties,physiological property,cultivation management,development prospects,relationship with agriculture,and molecular level);varieties,physiology,cultivation and other aspects are the focus of current research hot spots;the researches on selection and breeding of variety and various physiological and ecological mechanisms,still need a breakthrough.展开更多
With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of l...With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of leaf disease of L. lanci-folium. In mid-June, the wilting rate of L. lancifolium in seriously-infected field was even up to 50%-70%. In some fields, the shoots of L. lancifolium even al wilted. The pathogen was isolated from the infected leaves of L. lancifolium. Its pathogenici-ty, spore morphology, 18S rDNA sequence and biological characteristics were stud-ied. The results showed the isolated pathogen was Alternaria alternate. The lethal temperature of mycelial growth was 55 ℃. The optimum pH was 6-7. Among the tested carbon sources and nitrogen sources, the optimum carbon source was mal-tose, and the optimum nitrogen source was yeast extract.展开更多
内河水上交通事故时有发生,对水路运输安全、高效发展带来威胁。研究提出一种基于自适应参数的DBSCAN(Density-Based Spatial Clustering of Applications with Noise)方法,用于识别内河事故黑点水域。该方法支持对邻域半径ε和邻域中...内河水上交通事故时有发生,对水路运输安全、高效发展带来威胁。研究提出一种基于自适应参数的DBSCAN(Density-Based Spatial Clustering of Applications with Noise)方法,用于识别内河事故黑点水域。该方法支持对邻域半径ε和邻域中数据对象数目阈值P_(min)参数的自动选取,可提高聚类分析的精度和效率。基于2010—2019年长江干线下游散货船舶事故数据开展案例研究,对各典型事故黑点段的事故特征和事故原因进行分析,得到8个事故黑点。此外,采用Getis-Ord General G聚类识别事故黑点中的高等级事故区域,得到事故黑点及高等级事故主要分布于江心洲、桥区、港口码头区域。研究结果与实际情况基本吻合,一定程度上表明了该方法在内河水上交通事故分布特征分析上的科学性和实用性。展开更多
随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,...随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,并结合经纬度和事故严重程度信息揭示了潜在的高风险区域,从而为地区海事安全管理与事故预防提供科学依据。展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFD1200503)Jiangsu Agriculture Science and Technology Innovation Fund[Grant Nos.SCX(22)3215],Fundamental Research Funds for the Central Universities(Grant No.JCQY201901)the Earmarked Fund for China Agriculture Research System(Grant No.CARS-28).
文摘The mitogen-activated protein kinase(MAPK)cascade is crucial to plant growth,development,and stress responses.MAPK kinases(MAPKK)play a vital role in linking upstream MAPKK kinases(MAPKKK)with the downstream MAPK.Black spot is one of the most serious fungal diseases of pear which is an important part of the fruit industry in China.The MAPKK genes have been identified in many plants,however,none has been reported in pear(Pyrus bretschneideri).In order to explore whether MAPK gene of pear is related to black spot disease,we designed this experiment.The present study investigated eight putative PbrMAPKK genes obtained from the Chinese white pear genome.The phylogenetic analysis revealed that PbrMAPKK genes were divided into A,B,C,and D groups.These PbrMAPKK genes are randomly distributed on 7 out of 17 chromosomes and mainly originated from the whole-genome duplication(WGD)event.The expression analysis of PbrMAPKK genes in seven pear tissues and the leaves of susceptible and resistant varieties after Alternaria alternata infection by quantitative real-time PCR(qRT-PCR)identified seven candidate genes associated with resistance.Furthermore,virus-induced gene silencing(VIGS)indicated that PbrMAPKK6 gene enhanced resistance to pear black spot disease in pear.
文摘This study aimed at determining the spatial patterns of Road Traffic Crash (RTC) black spots, Federal Road Safety Commission (FRSC) zebra points and emergency health care facilities in Federal Capital City (FCC). The aim was to provide stakeholders with information that will aid their understanding of accident prone locations and accessible rescue possibilities for accident victims on the roads in FCT. GPS Map 76S Mark (GARMIN) was used to locate and pick coordinates of data in the study area. A total of 16 possible emergency health care facilities, seventy (70) RTC black spots and Five Zebra point locations were obtained from FRSC. ArcGIS 10.0 was used to compute the data by plotting the coordinates to produce maps of the spatial relationship and to carry out Nearest Neighbour Analysis (NNA). The result was further used to determine the spatial patterns of RTC black spots as well as patterns of the emergency facilities. Generally, the result shows that the spatial trend is turning towards dispersion. However, there is less than 1% likelihood that the dispersed patterns could be the result of random chance. It was recommended that, the Federal Road Safety Commission should be staffed with trained professionals that can be responsible for accident data surveillance and analysis using geospatial techniques.
文摘[Objective]The aim was to isolate and identify the pathogen causing black spot disease in guava(Psidium guajava),so as to determine its taxonomic status.[Method]The fungus was identified by determining its pathogenicity,observing its morphology characteristics and analyzing its ITS sequence.[Result]The pathogen causing black spot disease in guava was a strain of Guignardia mangiferae.[Conclusion]This study will provide theoretical basis for curing black spot disease of guava.
文摘[Objective] Disease analysis and pathogen identification of black spot disease of Chinese cabbage [Alternaria brassicae(Berk.) Sace.] in Bijie City of Guizhou Province was carried out,so as to raise the corresponding prevention measures.[Method] Pathogen was isolated from diseased leaves using tissue surface separation method for cultivation,microscopic examination,spore size determination and pathogen identification.[Result] Microscopic examination showed that the disease was caused by Alternaria sp.,the size of its spores was(15.0-38.5) μm×(7.5-13.5) μm.Combining with the characteristics of host and pathogen,the pathogen caused black spot disease of Chinese cabbage was identified to be Alternaria brassicicola.[Conclusion] A.brassicicola was the pathogenic fungi of black spot disease of Chinese cabbage in Bijie City of Guizhou Province,and damage caused by the disease could be reduced through agricultural measures and chemical control.
文摘柑橘黑斑病(Citrus Black Spot,CBS)主要危害果实,在果皮上形成各种病斑而影响果实的外观品质和销售价格,严重时可造成田间落果和贮藏期果实腐烂。同时,黑斑病被欧盟列为A1类外来有害生物,美国对此也有严格的限制。因此,该病害影响柑橘鲜果的国际贸易。黑斑病的病原属球座菌(Guignardia),其无性态为叶点霉菌(Phyl-losticta)。宽皮柑橘(Citrus reticulata)、橙类(C.sinensis)和柠檬(C.limon)上为柑橘球座菌(G.citricarpa),无性态为柑橘叶点霉(P.citricarpa)。而最新研究表明亚洲柚黑斑病(也称tan spot,棕褐斑病)的病原与上述柑橘上的不同,其有性态尚未发现,无性态则为亚洲柑橘叶点霉菌(P.citriasiana)。此外,P.capitalensis作为一种内生菌普遍存在于各类柑橘中,常干扰病害的检测。鉴于该病害在我国发生普遍,局部危害严重,而相关信息匮乏,作者综合国内外相关研究报道,结合自身部分工作,就病害发生历史、分布和危害性,病害症状,病原菌种类,发生规律和检测,病害在欧盟国家的发生风险,以及病害的防治等方面作了较为详细的介绍,以期满足读者对柑橘黑斑病的全方位了解需求。
基金Supported by Science and Technology Research Project of Chongqing Municipal Education Commission(KJ111307)
文摘Taking tumorous stem mustard infected by black spot disease as the research material, the ribosomal 5.8S rDNA and its flanking ITS region were cloned, sequenced and aligned in the study. The results showed that the base sequence of pathogens collected from five different sites was almost identical with that of Alternaria brassicae, and the similarity degree reached 99.68%, without base difference greater than 3 bp. It had obvious differences with the sequences of A. brassicicola and A. japonica, and the base difference was greater than 3 bp with a lot of fragment deletions. It was preliminarily determined that the pathogen cau- sing black spot disease on tumorous stem mustard was A. brassicae.
文摘In this study,the factors affecting the formation of small black spot defects on the surface of a hot-dip galvanized pure zinc strip are analyzed. These defects are primarily formed w hen the iron-aluminum inhibition layer is incompletely formed or fails to form or when foreign matter adheres to the surface or embeds in the zinc layer.The defects can be reduced by controlling the cleanliness and activity of the strip base before coating,regulating the zinc pot process parameters,and ensuring the cleanliness of the passline and workshop.
基金Supported by Innovation Fund of Beijing Academy of Agriculture and Forestry Science(KJCX20140109,KJCX20140202)Technology Innovation Team Fund of Beijing Academy of Agriculture and Forestry Science(KJCXTD201308)Flower Breeding Innovation Platform Project of Beijing Municipal Bureau of Landscape and Forestry
文摘Marigold ( Tagetes erecta) originated in South America is the main raw material of lutein, which plays a vital role in treating maeula lutea retinae, im- proving immunity and delaying aging. Black spot is the main disease reducing marigold production. This paper concluded occurrence and damage of black spot, the species and symptoms of pathogens, pathogenic factors, selection of disease-resistant varieties and effective means against black spot, and made a briefly analysis of the existing problems and the corresponding solutions, in order to provide a theoretical basis for disease-resistant breeding of marigold.
文摘In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is closely related to plant residues,rainfall,cultivation conditions and varieties.On the basis of understanding the symptoms and occurrence regularity of Chinese rose black spot,combination measures of agricultural and chemical prevention and control should be taken.
文摘In general, the location of traffic accidents is described as an address with text, so they are difficult to display on the map. The paper discusses how to utilize the geocoding technology and VRS-GPS positioning technology to record the traffic accidents with Geo-spatial information. Based on the spatial relationship between traffic accidents and road network elements, two-way association relationship is defined by spatial relationship computation. Then the paper presents the method which takes the potential of reducing accidents as an index to extract the black spots. Finally, in the discussion, the association relationship between black spots and traffic attributes is used to analyze the factors that resulting in traffic accidents.
文摘This paper describes the development of a hyperspectral imaging approach for identifying fruits infected with citrus black spot(CBS).Hyperspectral images were taken of healthy fruit and those with CBS symptoms or other potentially confounding peel conditions such as greasy spot,wind scar,or melanose.Spectral angle mapper(SAM)and spectral information divergence(SID)hyperspectral analysis approaches were used to classify fruit samples into two classes:CBS or non-CBS.The classification accuracy for CBS with SAM approach was 97.90%,and 97.14% with SID.The combination of hyperspectral images and two classification approaches(SID and SAM)have proven to be effective in recognizing CBS in the presence of other potentially confounding fruit peel conditions.The study result can be a reference for the non-destructive detection of fruits infected with citrus black spot.
基金the Beijing-Qinhuangdao Management Office of Hebei Province Expresswayfunding support from the National Natural Science Foundation of China(51678212)named“Analysis and Application of Large Area Road Network Connectivity Reliability Based on Earthquake Damage Range and Intensity Space Attenuation”+1 种基金Project of Hebei Provincial Science and Technology Department(E2019202449)named“Research on Key Technologies of Transportation System Planning under the Coordinated Development of City Groups”Project of Hebei Provincial Department of Human Resources and Social Security(A201905003)named“Analysis of Urban Road Network Resilience”。
文摘The identification of accident black spots is of great significance for the prevention of traffic accidents.Commonly used accident black spot identification methods divide road sections for the analysis of accident data,the direct result of which is the splitting of accident black spots,which affects the results.This paper is based on three years of traffic accident data from the Beijing-Harbin Expressway,including the time and location of traffic accidents,form of the accident fatalities,severe injuries,slight injuries,and property damage only(PDO).To avoid road division effects,an identification method based on the accident spacing distribution is established by using quality control theory.The results show that the average number of accidents per kilometer by the method proposed in this paper is 42,which is much higher than 10,identified by other identification methods.The method proposed in this paper improves the accuracy of the identification results.This method avoids the problem of road segmentation found in other common methods and can more accurately reflect the spatial distribution of traffic accidents.Thus making the identification of accidents more scientific and accurate.
文摘The damage characteristics and occurrence regularity of radish alternaria leaf spot, black rot, soft rot, virus disease and hollowness are introduced in the paper, and the corresponding control method is proposed from two aspects of agricultural control and chemical control.
文摘Taking the research papers on black peanut in National Knowledge Infrastructure(CNKI)as data sources,we determine the research hot spots on black peanut using word frequency analysis,and analyze the main research directions that change over the years.The results show that the relevant researches on black peanut are mainly concentrated in six themes(study of varieties,physiological property,cultivation management,development prospects,relationship with agriculture,and molecular level);varieties,physiology,cultivation and other aspects are the focus of current research hot spots;the researches on selection and breeding of variety and various physiological and ecological mechanisms,still need a breakthrough.
基金Supported by Modern Agricultural Industry Technology System Project of Ministry of Agriculture(nycytx-35-02-06)Key Program for Applied Basic Research of Agriculture of Hubei Provincial Science and Technology Plan Project(2012DBA07)~~
文摘With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of leaf disease of L. lanci-folium. In mid-June, the wilting rate of L. lancifolium in seriously-infected field was even up to 50%-70%. In some fields, the shoots of L. lancifolium even al wilted. The pathogen was isolated from the infected leaves of L. lancifolium. Its pathogenici-ty, spore morphology, 18S rDNA sequence and biological characteristics were stud-ied. The results showed the isolated pathogen was Alternaria alternate. The lethal temperature of mycelial growth was 55 ℃. The optimum pH was 6-7. Among the tested carbon sources and nitrogen sources, the optimum carbon source was mal-tose, and the optimum nitrogen source was yeast extract.
文摘内河水上交通事故时有发生,对水路运输安全、高效发展带来威胁。研究提出一种基于自适应参数的DBSCAN(Density-Based Spatial Clustering of Applications with Noise)方法,用于识别内河事故黑点水域。该方法支持对邻域半径ε和邻域中数据对象数目阈值P_(min)参数的自动选取,可提高聚类分析的精度和效率。基于2010—2019年长江干线下游散货船舶事故数据开展案例研究,对各典型事故黑点段的事故特征和事故原因进行分析,得到8个事故黑点。此外,采用Getis-Ord General G聚类识别事故黑点中的高等级事故区域,得到事故黑点及高等级事故主要分布于江心洲、桥区、港口码头区域。研究结果与实际情况基本吻合,一定程度上表明了该方法在内河水上交通事故分布特征分析上的科学性和实用性。
文摘随着我国港口吞吐量日益增长,沿海水域交通变得繁忙且船舶事故时有发生。以舟山水域作为研究对象,利用热力图、DBSCAN聚类算法及Getis-Ord General G分析方法对舟山船舶事故数据进行综合分析,识别水域交通事故黑点,提供事故的空间分布,并结合经纬度和事故严重程度信息揭示了潜在的高风险区域,从而为地区海事安全管理与事故预防提供科学依据。