Volterra积分方程解的存在性     

端木连喜 《临沂师范学院学报》2004,26(3):22-25

建立了Volterra积分方程存在三个非负解的一些标准，并给出了结论的具体运用．问题的证明中运用了LeggettWilliams不定点理论．  相似文献   

Development of a chemically defined medium for Planctopirus limnophila to increase biomass production     

《Electronic Journal of Biotechnology》2021

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.  相似文献   

本科教学改革的系统思考——以“高考不分文理”改革目标为背景     

高耀明 《复旦教育论坛》2014,(6)

"高考不分文理"将为大学推进本科教学改革和实施通识教育带来契机。本文以"高考不分文理"改革目标为背景,运用系统思考原理,讨论了大学本科教学改革的成长上限,揭示了本科教学改革的高杠杆解,并尝试提出了本科教学改革的路径:把课程实施大纲作为本科教学改革的高杠杆解,通过推行课程实施大纲,分三步持续推进本科教学改革,实现本科通识教育的改革目标。  相似文献   

论英汉文学翻译中的语言美--兼议英汉翻译语体风格的转换     

肖宜宁  刘恺 《九江职业技术学院学报》2003,(4):60-61

本立足于翻译的标准和原则，结合笔的翻译实践，从语体角度阐述英汉翻译中的语言美现象。  相似文献   

Reexamining Fear Appeal Models from Cognitive Appraisal Theory and Functional Emotion Theory Perspectives     

Jiyeon So  Kai Kuang  Hyunyi Cho 《Communication monographs》2016,83(1):120-144

Recognizing inconsistencies between the extant fear appeal theories and emotion literature, this research integrated cognitive appraisal theory and functional emotion theory into a fear appeal literature and proposed a model that describes a process through which both fear and anxiety can contribute to adaptive responses. Findings from an experiment (N = 927) supported the predictions. Fear and anxiety emerged as distinct constructs. Perceived susceptibility was a stronger predictor of anxiety than fear, while perceived severity was a stronger predictor of fear than anxiety. In addition, greater fear and anxiety led to greater response efficacy through increased motivation to obtain protection-related information and heightened attention to such information, thus mediating the threat and coping appraisal processes. The SEM model testing the predictions showed that perceived susceptibility had the strongest total effects on protection intention, followed by anxiety, perceived severity, and fear.  相似文献   

男高音训练之我见     

金卫国 《阜阳师范学院学报(社会科学版)》2001,(2):95-96,107

本文论述了训练男高音中声区、换声区,高声区的各种手法,结合教学实践,略述管见。  相似文献   

关于后方交会的一些误区     

周洪华  董亚宁  法惟刚 《辽宁科技学院学报》2005,7(3):12-15

文章分析了在一个角度和一个三角形中进行后方交会时最佳点位的规律,指出某些规程中有关后方交会问题的不足之处.  相似文献   

目标练习法在中长跑教学中的应用     

吴向民  卢东升 《九江职业技术学院学报》2004,(3):57-57,60

本文就提高学生耐久跑成绩的练习方法进行研究，通过分析、比较，提出适合中学生耐久跑教学的目标练习法，对增强教学环节、促进学生成绩提高有较好的作用。  相似文献   

修辞·修辞学·接受修辞学     

王卫兵  曹德和 《毕节学院学报》2007,25(1):8-11

修辞是指编码,随意改变其含义将会产生多米诺骨牌效应,导致修辞学丧失自身特征。修辞学以揭示编码规律为己任,但不等于无需研究解码,研究任务和研究范围是两码事,后者覆盖面总是大于前者覆盖面。接受修辞学概念可以成立,但是作为修辞学的下位学科,应当把落脚点放在编码上。  相似文献   

关于非游荡点集的等价描述   总被引：1，自引：0，他引：1  

林银河 《丽水学院学报》2005,27(2):11-12

非游荡点集为拓扑动力系统中所涉及到的一类重要点集。在《动力系统基础》的基础上对非游荡点作进一步描述,获得几个有用的结果。  相似文献