The growth character and microstructure of high-T_c supereonducting YBCO thin films deposited on vari- ous substrates have been studied by X-ray diffraction, TEM and SEM.The results show that when the substrate temper...The growth character and microstructure of high-T_c supereonducting YBCO thin films deposited on vari- ous substrates have been studied by X-ray diffraction, TEM and SEM.The results show that when the substrate temperaturc is around 700～800℃ the films have a highly oriented texture with c-axis pependicular to the substrate. The structure of the single crystalline YBCO films grown epitaxially at optimal substrate tem- perature of 800℃ has been established by X-ray diffraction using Seemann-Bohlin geometry (SB). Brentano-Bragg geometry(BB),transmission Laue method and TEM. The lattice matching required for epitaxial growth is achievcd by azimuthal adjustment of the film plane with respect to the substrate plane. The sperior growth is demonstrated by film properties such as critical current density(2.4×10~6 A /cm^2,3.4× 10~6 A/cm^2 and 4.7×l0~6 A/cm^2) for films deposited on YSZ[(Zr(Y)O_2],SrTiO_3 and LaAIO_3 respectively at 77 K and zero fie1d.展开更多
Aloe vera (L.) Burm.f. is one of the important medicinal plants, has been commercially cultivated in the Northern part of Bangladesh. An experiment was conducted to detect A. vera leaf disease collected from Natore di...Aloe vera (L.) Burm.f. is one of the important medicinal plants, has been commercially cultivated in the Northern part of Bangladesh. An experiment was conducted to detect A. vera leaf disease collected from Natore district, Bangladesh. Fungal leaf spot disease caused by Pseudopestalotiopsis theae (Sawada) Maharachch., K.D. Hyde & Crous was identified through morphological features and sequencing of internal transcribed spacer region of ribosomal DNA. After submitting nucleotide sequences to NCBI, we received an accession number MH333081.1: Pseudopestalotiopsis theae. The growth pattern of the isolated fungal pathogen was evaluated on different solid culture media, at different temperature and light conditions. The results showed the maximum mycelial growth of the fungus on the Richard Agar medium under the complete dark condition at 25°C. We evaluated fungal antagonists against the isolated pathogenic fungus, in which Trichoderma asperellum showed optimistic results. Synthetic fungicides—Tilt 250EC and Ridomil Gold completely inhibited the studied fungus’s vegetative growth. Pseudopestalotiopsis theae causing A. vera leaf spot disease in Bangladesh is a new record to the best of our knowledge.展开更多
文摘The growth character and microstructure of high-T_c supereonducting YBCO thin films deposited on vari- ous substrates have been studied by X-ray diffraction, TEM and SEM.The results show that when the substrate temperaturc is around 700～800℃ the films have a highly oriented texture with c-axis pependicular to the substrate. The structure of the single crystalline YBCO films grown epitaxially at optimal substrate tem- perature of 800℃ has been established by X-ray diffraction using Seemann-Bohlin geometry (SB). Brentano-Bragg geometry(BB),transmission Laue method and TEM. The lattice matching required for epitaxial growth is achievcd by azimuthal adjustment of the film plane with respect to the substrate plane. The sperior growth is demonstrated by film properties such as critical current density(2.4×10~6 A /cm^2,3.4× 10~6 A/cm^2 and 4.7×l0~6 A/cm^2) for films deposited on YSZ[(Zr(Y)O_2],SrTiO_3 and LaAIO_3 respectively at 77 K and zero fie1d.
文摘Aloe vera (L.) Burm.f. is one of the important medicinal plants, has been commercially cultivated in the Northern part of Bangladesh. An experiment was conducted to detect A. vera leaf disease collected from Natore district, Bangladesh. Fungal leaf spot disease caused by Pseudopestalotiopsis theae (Sawada) Maharachch., K.D. Hyde & Crous was identified through morphological features and sequencing of internal transcribed spacer region of ribosomal DNA. After submitting nucleotide sequences to NCBI, we received an accession number MH333081.1: Pseudopestalotiopsis theae. The growth pattern of the isolated fungal pathogen was evaluated on different solid culture media, at different temperature and light conditions. The results showed the maximum mycelial growth of the fungus on the Richard Agar medium under the complete dark condition at 25°C. We evaluated fungal antagonists against the isolated pathogenic fungus, in which Trichoderma asperellum showed optimistic results. Synthetic fungicides—Tilt 250EC and Ridomil Gold completely inhibited the studied fungus’s vegetative growth. Pseudopestalotiopsis theae causing A. vera leaf spot disease in Bangladesh is a new record to the best of our knowledge.
