Job management is a key issue in computational grids, and normally involves job definition, scheduling, executing and monitoring. However, job management in the existing grid middleware needs to be improved in terms o...Job management is a key issue in computational grids, and normally involves job definition, scheduling, executing and monitoring. However, job management in the existing grid middleware needs to be improved in terms of efficiency and flexibility. This paper addresses a flexible architecture for job management with detailed design and implementation. Frameworks for job scheduling and monitoring, as two important aspects, are also presented. The proposed job management has the advantages of reusability of job definition, flexible and automatic file operation, visual steering of file transfer and job execution, and adaptive application job scheduler. A job management wizard is designed to implement each step. Therefore, what the grid user needs to do is only to define the job by constructing necessary information at runtime. In addition, the job space is adopted to ensure the security of the job management. Experimental results showed that this approach is user-friendly and system efficient.展开更多
Diamond films were synthesized on Si substrate by electron-assisted chemical vapor deposition method using gas mixtures of methane(or acetone)and hydrogen.Various crystal structures of diamond films were obtained by s...Diamond films were synthesized on Si substrate by electron-assisted chemical vapor deposition method using gas mixtures of methane(or acetone)and hydrogen.Various crystal structures of diamond films were obtained by synthesis with various deposition conditions.The influences of various deposition conditions on thermal conductivity of diamond film were studied.The results show that large-grain(100)-oriented diamond films synthesized at lower concentration of methane and acetone have higher thermal conductivity,and thermal conductivity increases with the increasing in film thickness and the removal of the Sic layer on the back of the film,at last,annealing in ambience of hydrogen is advantageous to acquiring diamond film with high thermal conductivity.展开更多
Diamond films(DF)have been deposited on AlN ceramic substrates by hot filament chemical vapour deposition method.The diamond nucleation on AlN ceramics has been investigated.A nucleation density more than 10^(8) cm^(-...Diamond films(DF)have been deposited on AlN ceramic substrates by hot filament chemical vapour deposition method.The diamond nucleation on AlN ceramics has been investigated.A nucleation density more than 10^(8) cm^(-2) was obtained on this kind of insulating polycrystalline substrate under common deposition conditions.The thermal conductance of the DF/AlN compound materials has been studied by photothermal deflection technique.The thermal diffusivity of the DF/AlN is higher than that of the AlN ceramics,and will increase as the diamond films grow thicker.展开更多
Diamond films of various thickness(1-300μm)were deposited on single-crystal Si active(300μm)by a microwave plasma chemical vapor deposition method using gaseous mixtures of methane and hydrogen.After thinning of the...Diamond films of various thickness(1-300μm)were deposited on single-crystal Si active(300μm)by a microwave plasma chemical vapor deposition method using gaseous mixtures of methane and hydrogen.After thinning of the Si layer by machine and ion-beam polishing a diamond-based silicon-on-insulator structure with final Si layer thickness of about 1μm is formed.Thermal conductivity of this structure material with various thicknesses of diamond and Si layer was measured.Compared with bulk silicon,the thermal conductivity of the siliconon-diamond structure with 300μm diamond and 1μm silicon increases by 850%.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 90412014), the National Science Foundation of China for Distinguished Young Scholars (No. 60225009), and the China Next Generation Internet (CNGI) Project (No. CNGI-04-15-7A)
文摘Job management is a key issue in computational grids, and normally involves job definition, scheduling, executing and monitoring. However, job management in the existing grid middleware needs to be improved in terms of efficiency and flexibility. This paper addresses a flexible architecture for job management with detailed design and implementation. Frameworks for job scheduling and monitoring, as two important aspects, are also presented. The proposed job management has the advantages of reusability of job definition, flexible and automatic file operation, visual steering of file transfer and job execution, and adaptive application job scheduler. A job management wizard is designed to implement each step. Therefore, what the grid user needs to do is only to define the job by constructing necessary information at runtime. In addition, the job space is adopted to ensure the security of the job management. Experimental results showed that this approach is user-friendly and system efficient.
文摘Diamond films were synthesized on Si substrate by electron-assisted chemical vapor deposition method using gas mixtures of methane(or acetone)and hydrogen.Various crystal structures of diamond films were obtained by synthesis with various deposition conditions.The influences of various deposition conditions on thermal conductivity of diamond film were studied.The results show that large-grain(100)-oriented diamond films synthesized at lower concentration of methane and acetone have higher thermal conductivity,and thermal conductivity increases with the increasing in film thickness and the removal of the Sic layer on the back of the film,at last,annealing in ambience of hydrogen is advantageous to acquiring diamond film with high thermal conductivity.
基金Supported by the National Advanced Material Committee of China。
文摘Diamond films(DF)have been deposited on AlN ceramic substrates by hot filament chemical vapour deposition method.The diamond nucleation on AlN ceramics has been investigated.A nucleation density more than 10^(8) cm^(-2) was obtained on this kind of insulating polycrystalline substrate under common deposition conditions.The thermal conductance of the DF/AlN compound materials has been studied by photothermal deflection technique.The thermal diffusivity of the DF/AlN is higher than that of the AlN ceramics,and will increase as the diamond films grow thicker.
文摘Diamond films of various thickness(1-300μm)were deposited on single-crystal Si active(300μm)by a microwave plasma chemical vapor deposition method using gaseous mixtures of methane and hydrogen.After thinning of the Si layer by machine and ion-beam polishing a diamond-based silicon-on-insulator structure with final Si layer thickness of about 1μm is formed.Thermal conductivity of this structure material with various thicknesses of diamond and Si layer was measured.Compared with bulk silicon,the thermal conductivity of the siliconon-diamond structure with 300μm diamond and 1μm silicon increases by 850%.
