On-line monitoring of glucose and penicillin by sequential injection analysis

A sequential injection analysis (SIA) system has been developed for on-line monitoring of glucose and penicillin during cultivations of the filamentous fungus Penicillium chrysogenum. The SIA system consists of a peristaltic pump, an injection valve, two piston pumps, two multi-position valves and a detector. The glucose analyzer is based on an enzymatic reaction using glucose oxidase, which converts glucose to glucono-lactone with formation of hydrogen peroxide and subsequent detection of H₂O₂ by a chemiluminescence reaction involving luminol. The penicillin analysis is based on formation of penicilloic acid by penicillinase. Penicilloic acid is detected either by a chemiluminescence method or by a decolorization method. In the chemiluminescence method the penicilloic acid is quantified by its quenching effect on the chemiluminescence signal obtained when luminol reacts with iodine. In the decolorization method the penicilloic acid is detected spectrophotometrically by the decrease in the absorbance of an iodine-starch complex.     

计算机实验室与应用型创新人才培养探讨

计算机实验室承担大学生在计算机上做实验的基础课、专业课、选修课和学科竞赛等各专业实验教学任务。通过对实验室在高校创新人才培养中存在问题和重要性进行分析,以计算机实验室为例研究了实验室与应用型创新人才培养之间的关系,以培养大学生计算机的综合应用能力和创新能力为目标的开放、互联、共享计算机实验室对应用性创新人才培养发挥了重要作用。     

Existence and uniqueness of solutions for a hierarchical system of two age-structured populations

We propose a class of new hierarchical model for the evolution of two interacting age-structured populations, which is a system of integro-partial differential equations with global feedback boundary conditions and may describe the interactions such as competition, cooperation and predator-prey relation. Based upon a group of natural conditions, the existence and uniqueness of solutions on infinite time interval are proved by means of fixed point and extension principle, and the continuous dependence of the solution on the initial age distribution is established. These results lay a sound basis for the investigation of stability, controllability and variable optimal control problems.