鸡心辅酶Q-细胞色素c还原酶亲和层析分离及亚基拆分

本文证明鸡心线粒体辅酶Q-细胞色素c还原酶,于低离子强度下经Triton X-100增溶,亲和层析分离,得到单分散相的酶-Triton复合物。每微克分子酶含有低于0.15μmol辅酶Q以及12μmol的磷脂。还原态鸡酶的细胞色素b在α区表现两个吸收高峰,位于558,562nm;细胞色素c_1的α-吸收峰为553nm。SDS凝胶电泳指出,纯化的酶复合物至少由9个亚基组成。在高浓度盐和Triton X-100的作用下,酶复合物被解离为亚基复合物。三只氧化还原亚基(细胞色素b,c_1和Fe-S蛋白)被进一步分离、纯化。     

CHICKEN HEART UBIQUINOL:CYTOCHROME c REDUCTASE——ISOLATION BY AFFINITY CHROMATOGRAPHY AND RESOLUTION OF ENZYME INTO SUBUNITS

Chicken heart mitochondrial ubiquinol: cytochrome c reduetase has been isolated as a monodisperse form by solubilization with Triton X-100 in low ionic strength and subsequent affinity chromatography. The enzyme complex contains less than 0.15μmol ubiquinone and 12 μmol phospholipid per μmol enzyme. The spectrum of cytochreme b in the reduced enzyme exhibited two maximum α-absorption bands at 558nm and 562nm; a shoulder at 553 nm for c_1. The purified enzyme complex consists of at least 9 subunits with apparent molecular weight of 47K, 44K, 36K, 31K, 25K, 17K, 15K, 12K and 9K. The enzyme complex has been dissociated into subdomains of subunits in the presence of increasing concentration of salt and Triton X-100. Three subunits carrying the redox centers (cytochrome b, cytochrome c_1, and Fe-S protein) have been further isolated.     

光学焦距测量误差分布的实验研究

为解决光学检测中的误差分布问题 ,提出了用实验方法验证其分布 ,而不是简单地依据经验估计其分布为均匀分布、三角分布或正态分布。通过人眼目视测量与CCD光电测试 ,分析比较大量的采样数据 ,通常人为操作因素及仪器机械精度是目视光学检测中的一个主要误差源 ,进而得到目视测焦距的误差分布 ,并进行拟合性检验     

Shocklets in compressible flows

The mechanism of shocklets is studied theoretically and numerically for the stationary fluid, uniform compressible flow, and boundary layer flow. The conditions that trigger shock waves for sound wave, weak discontinuity, and Tollmien-Schlichting （T-S） wave in compressible flows are investigated. The relations between the three types of waves and shocklets are further analyzed and discussed. Different stages of the shocklet formation process are simulated. The results show that the three waves in compressible flows will transfer to shocklets only when the initial disturbance amplitudes are greater than the certain threshold values. In compressible boundary layers, the shocklets evolved from T-S wave exist only in a finite region near the surface instead of the whole wavefront.     

正丁醇对钠钾ATP酶的影响

正丁醇对钠钾ATP酶的影响在不同温度表现不同,在膜的相交温度以下,主要为激活(正丁醇浓度小于0.3克分子浓度),但在膜相交温度以上,正丁醇对酶活力主要起抑制作用.正丁醇对钠钾ATP酶的部分活力——对硝基酚磷酸酯酶活力仅起抑制作用,低温也不激活,这与对硝基酚磷酸酯酶活力的Arrhenius作图没有折点是一致的。实验提示在低温时与钠钾离子传送有关的构象变化是整个反应的限速因素,实验表明,利用正丁醇对膜脂进行微扰可以有助于了解钠钾ATP酶的作用原理。     

White Noise in Quantum Random Walk Search Algorithm

The quantum random walk is a possible approach to construct new quantum search algorithms. It has been shown by Shenvi et al. [Phys. Rev. A 67（2003）52307] that a kind of algorithm can perform an oracle search on a database of N items with O（√N） calling to the oracle, yielding a speedup similar to other quantum search algorithms. We study the effect of white or Gaussian noise on this algorithm. The algorithm loses efficiency when noise is added. We also show that noise on the target state plays a more important role than that on other states. Finally we compare the effects of similar types of noise in the quantum random walk search algorithm and Grover＇s search algorithm.     

具有图形用户界面的数字信号处理实验教学设计

介绍了具有图形用户界面的数字信号处理实验教学系统的设计。该系统由基本实验和综合实验两部分组成,预留了供学生外部编程的扩展接口,并与数据库相连,可远程在线使用,极大地方便了实验教学。实践证明,该系统能帮助学生加深对理论知识的理解,激发其学习兴趣,有效地提高了课堂的教学质量。     

《数字信号处理》双语课程分层次教学的探讨

双语教学是高校教育的发展趋势,也是评价专业办学水平的一个重要标准。针对《数字信号处理》课程的多理论、多算法的特点,对《数字信号处理》双语课程的教学方法、教学目的和教学手段进行了探索,并就适应教学对象、分层次教学、提高教学互动等几个方面提出了建议。