天冬酰胺合成酶B抑制剂高效液相色谱筛选方法的建立与应用

建立了一种快速、高效测定天冬酰胺合成酶B(AS-B)酶活性的反相高效液相色谱法(RP-HPLC)。酶反应体系中的氨基酸经2,4-二硝基氟苯(DNFB)柱前衍生,通过RP-HPLC测定酶反应体系前后底物及产物的变化来分析酶的活性。采用的色谱柱为Agilent C18柱(250 mm×4.6 mm,5 μm),以50 mmol/L醋酸钠缓冲液(pH 6.2)-乙腈(体积比为15:85)为流动相,流速为1.0 mL/min,柱温为30 ℃,检测波长365 nm,于6 min内实现了各组分的基线分离。通过该方法测定反应动力学参数进行AS-B的抑制定量分析。将已知AS-B抑制剂L-谷氨酸-γ-甲酯作用于酶反应体系,测得的抑制剂的抑制常数与文献值相接近,证明该方法可用于AS-B抑制剂的筛选。     

风能发电物理实验教学探讨

利用自行研制的风能发电实验仪,在大学物理实验和近代物理实验教学中开设了风能发电实验内容.教学实践表明该内容新颖,学生兴趣浓厚,可方便直观的了解风能转换及利用的全过程.诸多影响风能发电效率的因素给学生留下对风能发电的思考,促进其综合素质的提高.     

Effects of Correlation between Network Structure and Dynamics of Oscillators on Synchronization Transition in a Kuramoto Model on Scale-Free Networks

A recent study has found an explosive synchronization in a Kurammoto model on scale-free networks when the natural frequencies of oscillators are equal to their degrees. In this work, we introduce a quantity to characterize the correlation between the structural and the dynamical properties and investigate the impacts of the correlation on the synchronization transition in the Kuramoto model on scale-free networks. We find that the synchronization transition may be either a continuous one or a discontinuous one depending on the correlation and that strong correlation always postpones both the transitions from the incoherent state to a synchronous one and the transition from a synchronous state to the incoherent one. We find that the dependence of the synchronization transition on the correlation is also valid for other types of distributions of natural frequency.