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21.
房宏 《天津科技大学学报》2003,(Z1)
通过教学实验的方法,对数学思想方法与学生数学解题能力的整合作了初步的探讨,提出了在教学中如何更好地运用数学思想方法来提高学生解题能力的原则。 相似文献
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Diana Cholico-González NoemíOrtiz Lara Mario Alberto Sánchez Miranda Ricardo Morales Es-trella Ramiro Escudero García Carlos A.León Patiño 《矿物冶金与材料学报》2021,28(4):603-611
The reduction behavior and metallization degree of magnetite concentrate with agave bagasse were investigated in an inert atmosphere. The effects of temperature, biomass content, and residence time on reduction experiments and metallization degree were investigated by X-ray diffraction and scanning electron microscopy. Compared with other types of biomass, agave bagasse had lower contents of nitrogen, sulfur, and ash. X-ray diffraction analysis showed that the metallization degree improved with increasing temperature and biomass content. Complete metallization was achieved at 1100°C for 30 min with 65:35 and 50:50 ratios of the magnetite concentrate to the agave bagasse. These results demonstrate that agave bagasse promotes the efficient metallization of magnetite concentrate without the external addition of a reducing agent. Therefore, this biomass is a technical suitable alternative to replace fossil fuels in steelmaking. 相似文献
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Summary
o-Aminoacetophenone is the major volatile product present in the mandibular gland secretion of the primitive fungus-growing antMycocepurus goeldii. This novel arthropod natural product is biosynthetically far removed from the aliphatic ketones and alcohols found in those genera of the tribe Attini that represent the main line of evolution. The divergent phylogenetic position ofMycocepurus, and possibly of other closely related genera, is emphasized.Deceased 相似文献
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Genome sequencing and analysis of Aspergillus oryzae 总被引:4,自引:0,他引:4
Machida M Asai K Sano M Tanaka T Kumagai T Terai G Kusumoto K Arima T Akita O Kashiwagi Y Abe K Gomi K Horiuchi H Kitamoto K Kobayashi T Takeuchi M Denning DW Galagan JE Nierman WC Yu J Archer DB Bennett JW Bhatnagar D Cleveland TE Fedorova ND Gotoh O Horikawa H Hosoyama A Ichinomiya M Igarashi R Iwashita K Juvvadi PR Kato M Kato Y Kin T Kokubun A Maeda H Maeyama N Maruyama J Nagasaki H Nakajima T Oda K Okada K Paulsen I Sakamoto K Sawano T Takahashi M Takase K Terabayashi Y Wortman JR Yamada O 《Nature》2005,438(7071):1157-1161
The genome of Aspergillus oryzae, a fungus important for the production of traditional fermented foods and beverages in Japan, has been sequenced. The ability to secrete large amounts of proteins and the development of a transformation system have facilitated the use of A. oryzae in modern biotechnology. Although both A. oryzae and Aspergillus flavus belong to the section Flavi of the subgenus Circumdati of Aspergillus, A. oryzae, unlike A. flavus, does not produce aflatoxin, and its long history of use in the food industry has proved its safety. Here we show that the 37-megabase (Mb) genome of A. oryzae contains 12,074 genes and is expanded by 7-9 Mb in comparison with the genomes of Aspergillus nidulans and Aspergillus fumigatus. Comparison of the three aspergilli species revealed the presence of syntenic blocks and A. oryzae-specific blocks (lacking synteny with A. nidulans and A. fumigatus) in a mosaic manner throughout the genome of A. oryzae. The blocks of A. oryzae-specific sequence are enriched for genes involved in metabolism, particularly those for the synthesis of secondary metabolites. Specific expansion of genes for secretory hydrolytic enzymes, amino acid metabolism and amino acid/sugar uptake transporters supports the idea that A. oryzae is an ideal microorganism for fermentation. 相似文献