青木香(Aristolochia debillis Sieb.et Zucc.)的抗菌活性     

吕金海  舒孝顺  胡兴  李国民 《怀化学院学报》2007,26(2):69-71

通过琼脂平板扩散试验和双倍稀释试验,对青木香(Aristolochia debillis Sieb.et Zucc.)的石油醚提取物、乙酸乙酯提取物和甲醇提取物进行了抗细菌和抗真菌作用的研究,在三种提取物中,只有甲醇提取物对试验的所有革兰氏阳性和革兰氏阴性细菌都表现出显著的抗菌作用,乙酸乙酯提取物只对测试的部分细菌显示出抗菌作用,石油醚提取物不具有抗菌活性.甲醇提取物比乙酸乙酯提取物具有更强的抗菌作用和更广的抗菌谱.三种提取物对所有试验的真菌都没有显示出抗菌作用.  相似文献   

Simulation‐based enhancement of learning: The case of food safety     

Ashim K. Datta  Mayuri S. Ukidwe  David G. Way 《Journal of Food Science Education》2020,19(3):192-211

Importance of online learning has become more critical with the advent of a global pandemic. Effective online learning requires design characteristics that support learning that crosses traditional disciplinary boundaries. The example of educational delivery of food safety encompasses multiple disciplines to prepare students for real‐world situations, practical problem‐solving, and to be “future proof” as food safety becomes more quantitative. This study explicates how six simulation‐based learning modules were evaluated, two each in microbiological growth/inactivation, food process dynamics with microbiological growth/inactivation, and risk assessment. Each group of three modules was targeted to the students in undergraduate food science and engineering programs. Altogether, the 6 modules were implemented and assessed in 17 courses at 14 universities over 5 years. The effectiveness of the module‐based approach was sustained across subject matter (microbiology, process, and risk), disciplines (food science and engineering), and their implementations. Students’ and instructors’ survey responses indicated the modules’ value in real‐world and practical problem‐solving ability. Instructors were also motivated to implement the modules as they saw the potential for improvement in student understanding, how modules reinforced course learning outcomes, the quality of support provided with modules, and their ability to replace existing course assessment without adding work for the instructor or the students. This self‐learning, module‐based approach to introduce interdisciplinary content employed has proven successful. The template for making these modules is described in sufficient detail so future modules can be built for a wide variety of subject matter beyond food safety.  相似文献   

台州市外来植物区系组成与分布特征的研究   总被引：3，自引：0，他引：3  

陈模舜 《台州学院学报》2008,30(6):43-48

通过野外调查和资料分析,并对外来植物的原产地、分布特点、引入途径等进行分析。结果表明,①台州目前有92种外来植物,属于39科,81属,其中有栽培种41种、归化种11种、外来人侵种40种;②台州市外来植物来自美洲52种,来自欧洲12种,分别占总数的56．52％和13．04％;③台州市外来植物在温岭分布最多（84种）,其次是椒江（81种）;④属的区系地理成分划分为13种分布区类型,热带分布成分（61．73％）比温带分布成分（38．27％）强,表现出台州来植物的过渡性和复杂性。  相似文献   

生物菌肥在不同水分条件下对土壤碱解氮的影响   总被引：2，自引：0，他引：2  

李云玲  延晋芳  侯沁文  谢英荷 《长治学院学报》2006,23(2):5-7

通过玉米盆栽试验,研究了不同水分条件下菌肥对土壤碱解氮的影响。结果表明:土壤含水量范围在9％-20％时,施用生物菌肥对提高土壤碱解氮有显著效果;不同的水分条件下菌肥发挥的肥效不同,土壤含水量为13％-16％时,菌肥对土壤碱解氮的影响最大,且玉米的生长状况良好。  相似文献   

梅州城市绿化植物区系研究     

廖富林  胡玉佳  杨期和 《嘉应学院学报》2005,23(3):43-45

经调查统计,梅州城区现有绿化植物432种,隶属128科261属,其中珍稀濒危植物4种.本文分析了梅州城市绿化植物的区系、性状和生态习性特点.研究结果表明,梅州城市绿化植物种类的选择实现了乡土植物与外来植物、热带植物与亚热带植物的结合,具有较强的亚热带性质和充分反映了南亚热带山城的特点基本原则,取得了显著成绩.  相似文献   

粤东地区植物区系组成分析   总被引：4，自引：1，他引：4  

陈蔚辉 《韩山师范学院学报》1994,(3)

粤东地区的植物区系组成种类丰富,区系成分以热带成分为主,区系性质为南亚热带——中亚热带植物区系的中间类型,但偏重于南亚热带,区系植物起源古老,孑遗植物较多,此外,该区系植物所构成的植被尚较多样.  相似文献   

苍山西坡漾濞地区种子植物区系成分的垂直分布格局     

冯建孟  李继红  王浩波  董晓东 《楚雄师范学院学报》2010,25(3):48-52,58

本研究利用野外考察信息和文献资料探讨了苍山西坡漾濞地区种子植物区系成分的垂直分布格局,结果表明,热带区系成分所占比重随着海拔的升高呈明显递减趋势,这与热带区系植物喜温的生态特性是一致的。温带区系成分所占比重总体上随着海拔的升高呈明显递增趋势,这与温带区系植物耐低温的生态特性是一致的。中国分布成分所占比重随着海拔的升高呈明显的递增趋势,具有温带植物区系的性质。随着海拔的升高,区系过渡性先呈递增趋势,然后呈递减趋势,在海拔2100 m-2200 m之间,区系过渡性达到峰值。  相似文献   

Bioinspired hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers     

Huai-Ling Gao  Ran Zhao  Chen Cui  Yin-Bo Zhu  Si-Ming Chen  Zhao Pan  Yu-Feng Meng  Shao-Meng Wen  Chuang Liu  Heng-An Wu  Shu-Hong Yu 《国家科学评论(英文版)》2020,7(1):73

Bio-sourced nanocellulosic materials are promising candidates for spinning high-performance sustainable macrofibers for advanced applications. Various strategies have been pursued to gain nanocellulose-based macrofibers with improved strength. However, nearly all of them have been achieved at the expense of their elongation and toughness. Inspired by the widely existed hierarchical helical and nanocomposite structural features in biosynthesized fibers exhibiting exceptional combinations of strength and toughness, we report a design strategy to make nanocellulose-based macrofibers with similar characteristics. By combining a facile wet-spinning process with a subsequent multiple wet-twisting procedure, we successfully obtain biomimetic hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers, realizing impressive improvement in their tensile strength, elongation and toughness simultaneously. The achievement certifies the validity of the bioinspired hierarchical helical and nanocomposite structural design proposed here. This bioinspired design strategy provides a potential platform for further optimizing or creating many more strong and tough nanocomposite fiber materials for diverse applications.  相似文献   

禽肉在储存过程中菌群结构变化研究     

周晓锋  张珍 《南京晓庄学院学报》2013,(3):39-41

研究禽肉储存过程中菌群的变化,为其长期贮存奠定理论基础.采用酚氯仿异戊醇法提取禽肉中菌群基因组DNA,并通过PCR扩增及DGGE电泳技术探讨其随保存时间延长,菌群结构变化情况.结果表明,成功扩增了菌群基因组DNA,为230bp.DGGE电泳结果发现,DGGE分子指纹图谱上条带存在显著的差异,用bionumberics软件分析DGGE结果,发现第一天和第二天样本的相似度最高为0.75,第三天与第一天相比,相似度为0.47,第四天与第三天相比,相似度又下降为0.16,表明禽肉在储存过程中不断有新的菌种出现,但是具体是什么菌种有待于高通量测序分析.  相似文献   

难处理金矿细菌预氧化-氰化提金工艺研究     

李岳姝 《鸡西大学学报》2013,(7):58-59

难处理金矿在我国黄金资源中占据较大的比例,常规处理原生矿的方法焙烧法与加压氧化法因成本太高,不适合处理该低品位金矿。因此,采取细菌预氧化-氰化提金工艺试验进行研究分析。试验研究表明,最终金浸出率58·8%,试验指标较为理想。  相似文献