为提高医院EPC项目管理效率,首先,依据霍尔的三维结构模式(Hard System Methodology,HSM)并结合医院工程总承包(Engineering Procurement Construction,EPC)项目的特点,构建了一个涵盖业务、组织、过程、信息、制度和资源六大子系统的医...为提高医院EPC项目管理效率,首先,依据霍尔的三维结构模式(Hard System Methodology,HSM)并结合医院工程总承包(Engineering Procurement Construction,EPC)项目的特点,构建了一个涵盖业务、组织、过程、信息、制度和资源六大子系统的医院EPC项目管理协同系统模型,基于此建立了医院EPC管理协同度评价指标体系;然后,运用改进的层次分析法确定指标权重,并结合序参量功效函数法对项目协同度进行量化计算,以此构建了医院EPC项目管理协同度评价模型;最后,以济南市某医院EPC项目为例,分析得出该项目各阶段的管理协同度、各子系统有序度及各序参量指标的敏感性程度。结果表明:该项目设计阶段和采购阶段的管理协同度处于低度协同水平,施工阶段处于低度不协同水平;在各子系统中,制度协同、业务协同、过程协同的有序度较低,应针对识别出的高敏感性指标进行改进。展开更多
Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient...Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient of thermal expansion （CTE） of 7.72 × 10-6 K-1 （25-100℃）, which are achieved by modifying the copper matrix with adding 0.3 wt.% of boron to get a good thermal contact between the matrix and the diamond particles. By adopting a series of postmachining techniques the composites were made into near-net-shape parts, and an electroless silver coating was also successfully plated on the composites. Finally, their potential applications in the thermal management of fight emitting diodes （LED） were illustrated via prototype examples.展开更多
AlSiCp （65 vol.% SiC） electronic packaging materials were manufactured by powder injection molding （PIM） and pressure infiltration process in order to obtain near net-shaped parts. SiCp preformed compacts obtained...AlSiCp （65 vol.% SiC） electronic packaging materials were manufactured by powder injection molding （PIM） and pressure infiltration process in order to obtain near net-shaped parts. SiCp preformed compacts obtained by pre-sintering process at 1150 K have high strength and good appearance, and the ratio of open porosity to total porosity is nearly 98%. The relative density of composites is bigger than 99%. The thermal conductivity of A1SiCp composites fabricated by this method is 198 W·m^-1·K^-1, and the coefficient of thermal expansion （CTE） is 8.0 × 10^-6/K （298 K）.展开更多
In this paper, a computational fluid flow model was adopted to investigate the effect of varying atomization gas pressure (P0) on the gas flow field in supersonic gas atomization. The influence of P0 on static pressur...In this paper, a computational fluid flow model was adopted to investigate the effect of varying atomization gas pressure (P0) on the gas flow field in supersonic gas atomization. The influence of P0 on static pressure and velocity magnitude of the central axis of the flow field was also examined. The numerical results indicate that the maximum gas velocity within the gas field increases with increasing P0. The aspiration pressure (ΔP) is found to decrease as P0 increases at a lower atomization gas pressure. However, at a higher atomization gas pressure increasing P0 causes the opposite: the higher atomization gas pressure, the higher aspiration pressure. The alternation of ΔP is caused by the variations of stagnation point pressure and location of Mach disk, while hardly by the location of stagnation point. A radical pressure gradient is formed along the tip of the delivery tube and increases as P0 increases.展开更多
文摘为提高医院EPC项目管理效率,首先,依据霍尔的三维结构模式(Hard System Methodology,HSM)并结合医院工程总承包(Engineering Procurement Construction,EPC)项目的特点,构建了一个涵盖业务、组织、过程、信息、制度和资源六大子系统的医院EPC项目管理协同系统模型,基于此建立了医院EPC管理协同度评价指标体系;然后,运用改进的层次分析法确定指标权重,并结合序参量功效函数法对项目协同度进行量化计算,以此构建了医院EPC项目管理协同度评价模型;最后,以济南市某医院EPC项目为例,分析得出该项目各阶段的管理协同度、各子系统有序度及各序参量指标的敏感性程度。结果表明:该项目设计阶段和采购阶段的管理协同度处于低度协同水平,施工阶段处于低度不协同水平;在各子系统中,制度协同、业务协同、过程协同的有序度较低,应针对识别出的高敏感性指标进行改进。
基金supported by the National Natural Science Foundation of China (No. 50971020)the National High-Tech Research and Development Program of China (No. 2008AA03Z505)
文摘Diamond reinforced copper （Cu/diamond） composites were prepared by a pressure infilla＇ation technique. The composites show a super high conductivity of 713 W.m-1.K-1 in combination with an extremely low coefficient of thermal expansion （CTE） of 7.72 × 10-6 K-1 （25-100℃）, which are achieved by modifying the copper matrix with adding 0.3 wt.% of boron to get a good thermal contact between the matrix and the diamond particles. By adopting a series of postmachining techniques the composites were made into near-net-shape parts, and an electroless silver coating was also successfully plated on the composites. Finally, their potential applications in the thermal management of fight emitting diodes （LED） were illustrated via prototype examples.
基金the National Natural Science Foundation of China (No. 50274014).
文摘AlSiCp （65 vol.% SiC） electronic packaging materials were manufactured by powder injection molding （PIM） and pressure infiltration process in order to obtain near net-shaped parts. SiCp preformed compacts obtained by pre-sintering process at 1150 K have high strength and good appearance, and the ratio of open porosity to total porosity is nearly 98%. The relative density of composites is bigger than 99%. The thermal conductivity of A1SiCp composites fabricated by this method is 198 W·m^-1·K^-1, and the coefficient of thermal expansion （CTE） is 8.0 × 10^-6/K （298 K）.
基金Supported by the National Engineering Technology Research Center Development Program (Grant No. NCSTE-2007-JKZX-054)
文摘In this paper, a computational fluid flow model was adopted to investigate the effect of varying atomization gas pressure (P0) on the gas flow field in supersonic gas atomization. The influence of P0 on static pressure and velocity magnitude of the central axis of the flow field was also examined. The numerical results indicate that the maximum gas velocity within the gas field increases with increasing P0. The aspiration pressure (ΔP) is found to decrease as P0 increases at a lower atomization gas pressure. However, at a higher atomization gas pressure increasing P0 causes the opposite: the higher atomization gas pressure, the higher aspiration pressure. The alternation of ΔP is caused by the variations of stagnation point pressure and location of Mach disk, while hardly by the location of stagnation point. A radical pressure gradient is formed along the tip of the delivery tube and increases as P0 increases.
