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This papercarries out a survey of sufficient schedulability analysis forfixed priority (FP) scheduling. The most common used fixed priority assignment is the rate monotonic (RM) algorithm, according to its policy, the task priorities are ordered based on their activation rates, so that the task with the shortest period is assigned the highest priority. However, when each task’s relative deadline is not equal to its period, the RM algorithm is not suitable to assign the task priorities. When relative deadlines are less than or equal to periods,the deadline monotonic (DM) algorithm can be deployed to schedule the tasks. The utilization based schedulability analysis has the advantage of simple implementation, and manyexisting schedulability analyses on uniprocessor are covered.

This paper focus on the schedulability analysis of fixed priority servers. A number of fixed priority servers and their schedulability analysis are reviewed, these results and properties can be used for constructing systems with different timing constraints, where real-time tasks with hard deadlines and the soft aperiodic tasks can be scheduled in the same system. The aperiodic tasks in the fixed priority servers are not preemptable, and they are scheduled in a first-come first-served manner. There is only one server with many periodic or sporadic tasks in the system. The tasks and the server are scheduled by a fixed priority algorithm such as rate monotonic or deadline monotonic.

This paper focus on hierarchical scheduling for real-time applications for open embedded system environments constructed by the total bandwidth server, according to its algorithms, when a job at the head of the server's ready queue completes, the server budget is replenished immediately if the ready queue is not empty. This paper gives some examples to the solutions proposed by Deng et al for a two-level hierarchical scheduling model in which the global level of the system is earliest deadline first, and the local scheduler could be any algorithm. The scheduling algorithms and schedulability analysis for the tasks are reviewed in an open system where the applications could be modeled as executing on a slow processor.

This paper focus on the dynamic server algorithms, and the servers are used for scheduling soft aperiodic tasks. Many types of servers and their schedulability analysis are reviewed, these properties can be used for constructing hierarchical embedded systems, where the soft aperiodic tasks and the hard real-time tasks can be scheduled in the same system. The aperiodic tasks in the server are not preemptable, and they are executed in a first-come first-served (FCFS) manner. If it is not specified, there is only one server in the system, and rest of the processes in the system are ordinary periodic tasks. The servers could be scheduled by fixed priority or dynamic algorithms.

This paper focus on two level hierarchical scheduling where several real-time applications are scheduled by the fixed priority algorithms. The application with its real-time tasks is bound to a server which can be modeled as a sporadic task with special care for the schedulability analysis. Different scheduling policies and servers can be applied for hierarchical fixed priority systems, this paper gives a closer review of schedulability analysis for applications and tasks when the global and local schedulers of a system are fixed priority.

Er3+,Yb3+:Y2O3nanocrystal up-conversion material has been prepared using the sodium carbonate precursor method and doped in the P25 to prepare up-conversion nano-TiO2powder. The micromorphology, structure and particle size of the up-converting nanoparticles were characterized by atom force microscopy (AFM) and X-ray diffraction (XRD). Nano-TiO2powder with up-conversion performance was applied to Dye-sensitized solar cells, the photoelectric conversion efficiency of the DSSC with up-conversion material is twice the photoelectric conversion efficiency of normal DSSC irradiated by infrared light.