32 research outputs found

    Morphological and phylogenetic analyzes reveal two new species of Melanconiella from Fujian Province, China

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    IntroductionSpecies of Melanconiella include a diverse array of plant pathogens as well as endophytic fungi. Members of this genus have been frequently collected from the family Betulaceae (birches) in Europe and North America. Little, however, if known concerning the distribution of Melanconiella and/or their potential as pathogens of other plant hosts.MethodsFungi were noted and isolated from diseased leaves of Loropetalum chinense (Chinese fringe flower) and Camellia sinensis (tea) in Fujian Province, China. Genomic DNA was extracted from fungal isolates and the nucleotide sequences of four loci were determined and sued to construct phylogenetic trees. Morphological characteristics of fungal structures were determined via microscopic analyses.ResultsFour strains and two new species of Melanconiella were isolated from infected leaves of L. chinense and C. sinensis in Fujian Province, China. Based on morphology and a multi-gene phylogeny of the internal transcribed spacer regions with the intervening 5.8S nrRNA gene (ITS), the 28S large subunit of nuclear ribosomal RNA (LSU), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF1-α), Melanconiellaloropetali sp. nov. and Melanconiellacamelliae sp. nov. were identified and described herein. Detailed descriptions, illustrations, and a key to the known species of Melanconiella are provided.DiscussionThese data identify new species of Melanconiella, expanding the potential range and distribution of these dark septate fungi. The developed keys provide a reference source for further characterization of these fungi

    Application of the Data from Landsat8 OLI - The New Generation of Landsat Series in the Cultivated Land Information Extraction

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    International audienceBy making use of the image data of Landsat8 OLI newly launched by the United States and taking Liaocheng, Shandong Province as an example, we conduct computer correction and enhancement for the remote sensing image data of Liaocheng through the adoption of ENVI (a remote sensing image processing software) to extract information of cultivated land with the methods of visual interpretation, supervised classification and unsupervised classification. The result shows that based on the combination of Band5, 4, 3 and Band6, 5, 2 of Landsat8 OLI data, a relatively satisfactory cultivated land information can be acquired through visual interpretation, interactive methods of supervised classification and unsupervised classification

    Method of Selecting Active Parameters Using Sensitivity Analysis and Linear Programming

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    It is necessary to select appropriate active parameters to ensure both the accuracy and computation efficiency before the global analysis of chemical kinetic model. This paper proposes a new method for selecting the active parameters on the base of the combination of sensitivity analysis and linear programming. Compared with the usual methods for selecting active parameters, such as the local sensitive analysis, the characteristics of the proposed method is preliminary visualization of the possible influence of the selected active parameters on the model outputs in the process of parameter selection, ensuring the reliability of the selected active parameters. Considering the computation efficiency, the number of selected active parameters can be controlled in a suitable size through combining with dichotomy or other screening techniques. In the study, the pre-exponential factors of the Arrhenius equations in the USC-Mech II model were considered as the candidate parameters and the uncertainties of the pre-exponential factors were set. Taking the ignition of ethylene for example, the 10 reactions that can increase the ignition time of ethylene under a wide range of conditions with equivalence ratio of 1, 0.1 similar to 1 MPa and 1000 K similar to 1500 K were successfully selected using the proposed method. Then, the 10 active parameters were tested in each condition. The results showed that the selected active parameters can make the ignition delay time close to the target for each condition, which reflects the reliability of active parameter selection

    Influence of Doped H2O or H(2)on Soot Production and Power Capability in the Fuel-rich Gas Generator

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    Influence of doped H2O or H(2)on both soot production and power capability in the fuel-rich gas generator has been studied together by using the program of chemical equilibrium with applications (CEA). The oxidant is LOX, and the fuel is composed of Jet-A and the additive. The parameters of the gas generator are as follows: the range of combustion temperature is 800-1700 K, combustion pressure is 0.1-5.0 MPa, oxidant/fuel ratio is 0.1-1.2, and the mass percent of the additive in fuel is 0-60%. The results indicate that the addition of either H2O or H(2)can obviously reduce the mass percent of soot in combustion products, and the reasons are discussed on the base of the products distributions. Moreover, the minimum amounts of addition to surrender mass percent of soot less than 0.1% are present. The effects of combustion pressure on soot mass percent in combustion products appear turning appoints around 1100 K, no matter the additive is H2O or H-2. The addition of H(2)can obviously improve the power capacity of combustion products in the whole temperature range. The addition of H2O can also improve slightly the power capacity of combustion products, when the combustion temperature is less than 1400 K. Effective molar weight of combustion products is the main factor affecting power capacity

    Hypergolic ignition modulated by head-on collision, intermixing and convective cooling of binary droplets with varying sizes

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    The hypergolic ignition induced by the head-on collision of TMEDA and WFNA droplets was experimentally investigated with emphasis on the effect of droplet size on the ignitibility and the ignition delay time. The ignitibility regime nomogram in We - d(o) space indicates that the reduction of droplet size tends to suppress the hypergolic ignition. The ignition delay time, which was precisely determined by using grayscale level analysis, becomes shorter for smaller droplets. The seemingly conflicting size effects were resolved by means of time scaling analysis to reveal the size dependence of the three pre-ignition processes, which were identified as the first stage of droplet collision, deformation and intermixing, the second stage of droplet heating from interior to surface, and the third stage of droplet vaporization subject to heat loss by convective cooling. (C) 2019 Elsevier Ltd. All rights reserved

    Accuracy Analysis of the Aerosol Backscatter Coefficient Profiles Derived from the CYY-2B Ceilometer

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    Ceilometers are originally designed for cloud base height monitoring. Since a few years, the number of ceilometers available worldwide is rapidly increasing, and these simple backscatter lidars are investigated to be used for aerosol research. This study presents an assessment of the potential of CYY-2B ceilometer for the quantitative retrieval of aerosol properties. The signal-to-noise ratio of the ceilometer is calculated, and the effective height of inversion is determined. It is shown that the effective height of the ceilometer for backscatter coefficient profile inversion is 3-4 km at night and about 1.5–2 km during the day, which is lower than that of the micropulse lidar (MPL) system. The accuracy of the backscatter coefficient profiles derived from the CYY-2B ceilometer is analyzed by using the Vaisala CL51 ceilometer, MPL, forward scatter visibility instrument, and aerosol optical depth (AOD) dataset from aerosol robotic network (AERONET). Spectral conversions of the ceilometer’s and lidar’s data are performed using the Ångström exponent estimated by AERONET measurements. A good agreement is found between two ceilometers and the MPL lidar in backscatter coefficient profiles inversion. The AODs agree well with the AERONET AODs during the observation period of small AODs. However, for the period of large AODs, the results are approximately 50%–60% of AERONET AODs. The limited range of extinction integration is the main cause of this problem

    Morphological and phylogenetic analyses reveal two new species of Sporocadaceae from Hainan, China

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    Species of Sporocadaceae have often been reported as plant pathogens, endophytes or saprophytes and are commonly isolated from a wide range of plant hosts. The isolated fungi were studied through a complete examination, based on multilocus phylogenies from combined datasets of ITS/tub2/tef1, in conjunction with morphological characteristics. Nine strains were isolated from Ficus microcarpa, Ilex chinensis and Schima superba in China which represented four species, viz., Monochaetia schimae sp. nov., Neopestalotiopsis haikouensis sp. nov., Neopestalotiopsis piceana and Pestalotiopsis licualicola. Neopestalotiopsis piceana was a new country record for China and first host record from Ficus macrocarpa. Pestalotiopsis licualicola was first report from Ilex chinensis in China
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