自来水中硝酸根的流动注射分光光度在线检测

建立了在线测定水中硝酸根的流动注射分光光度法，水样通过镉粒还原柱与对氨基苯磺酰胺溶液混和，将N－（1－萘基）－乙二胺溶液注入到此混合流，在λmax=540nm处进行光度检测，线性范围为0.01-2.0mg/L,检出限分别为0.01mg/L，测定频率为50次／h 。本法灵敏度高，选择性好，分析速度快。应用本法测定自来水中硝酸根，获得满意结果。     

Analysis of a New Type of Production System

Previous work studied a production system including multiple stations (or workshops) consisting of an entry station, a set of workstations, an exit station, and a central station, which could be arranged in any configuration. The central station was introduced into the production system to relax the environment. In this paper, the central station is eliminated. The entry station and all workstations have limited local buffers. A workstation can choose either a buffer or a kanban mechanism to control its work-in-process (WIP). The production system was modeled as a queueing network with blocking in a general configuration. A symmetrical decomposition approach was developed to analyze the production system. The simulation result shows that the decomposition approach works well. Comparison of the new production systems with modified production systems having a common buffer shows that the key for implementing just-in-time production systems is to reduce the uncertainty.