Actively tunable acoustic metamaterials have attracted ever increasing attention.However,their tunable frequency range is quite narrow(tens of Hz)even under ult
采用二苯代苦味酰基自由基消除率测定方法,在酶解条件即温度、酶解时间、料水比、pH值、加酶量五个因素中,固定四种因素变化其中一种因素来研究其酶解条件与抗氧化性的关系。试验结果表明大豆肽对二苯代苦味酰基自由基的清除率在水解4.5h时达到最高为33.09%、在pH值为9.0左右时达到最高为33.85%、在温度为60℃时达到最高为33.43%、在料水比1/6时达到最高为34.04%。大豆肽的酶解条件中温度、pH值、料水比在肽得率达到最大时,其抗氧化性也达到最大。
篇章语言学超越了“词本位”与“句本位”的传统语言学研究视角,拓宽了语言学研究的学术理路与体系建构。篇章语言学中的“衔接与连贯”“语篇文体”“语境”概念对于“高级英语”的课堂教学有着重要启示意义,突显了“高级英语”教学目标中的“三个侧重”,即“侧重于阅读与写作能力的提高”“侧重于文体学知识的培养”“侧重于人文知识的渗透”。篇章语言学的语言教学观开阔了“高级英语”的教学理论视野,丰富了具体的教学策略与方法,有利于英语专业学生语言综合运用能力与整体素质的提升。
Two-dimensional(2D)transition metal dichalcogenide(TMDC)monolayers,a class of ultrathin materials with a direct bandgap and high exciton binding energies,provid
针对珊瑚礁钙质砂的特殊结构可能影响钙质砂的压缩、剪切和破碎等力学性能这一问题,通过X射线衍射和X射线断层扫描等技术手段,研究了岛礁珊瑚礁钙质砂的物相组成、表面结构和内部结构等特征。研究结果表明:钙质砂物质组成以生物文石为主,镁方解石次之。钙质砂颗粒中的原生海洋生物碎屑较多,并保留有大量的原生构造,超过50%为珊瑚礁破碎、崩解和风化后的产物。钙质砂孔隙非常发育,孔隙差异性非常大,内孔隙率较大。孔隙率不仅取决于孔道直径,还取决于孔道的密集程度。
Metal sulfide based materials as photocatalysts for energy conversion are essential to produce value-added chemical fuels,but their intrinsically slow carrier d
Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-Pérot cavity-forming nanowires.We demonstrate the direct observa
Molecular interaction in two-dimensional(2D)van der Waals(vdW)interfaces has drawn tremendous attention for extraordinary materials characteristics.So far sensi
Developing antibiotics-independent antibacterial agents is of great importance since antibiotic therapy faces great challenges from drug resistance.Graphene oxi
There is a continuous demand to reduce the size of the devices that form a unit circuit,such as logic gates and memory,to reduce their footprint and increase de