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TFLOPS级HPC性能测试方案设计

计算机工程与应用 2004年第34期40卷 57-59,67页

作者：洪文董田浩北京高性能计算机应用中心国家气象中心高性能计算机室北京100081

在定购高性能计算机时要避免被所宣传的峰值性能误导而忽略实际可获得的应用性能。高性能计算(HPC)气象应用采用的方法是以实测定规模,设计了以实际预报模式为主、基准测试为辅的测试方案,由厂家在规定的时间内,对计算机的应用性能、系... 详细信息

在定购高性能计算机时要避免被所宣传的峰值性能误导而忽略实际可获得的应用性能。高性能计算(HPC)气象应用采用的方法是以实测定规模,设计了以实际预报模式为主、基准测试为辅的测试方案,由厂家在规定的时间内,对计算机的应用性能、系统管理及单项性能进行综合的测试。实测表明:测试可准确确定系统的配置规模;对于并行气象应用,向量机的性能是标量机的2-6倍;测出了某些系统的潜在问题。

关键词： HPC 性能测试气象应用

Microstructures of SrBi2Ta2O9 materials investigated by TEM

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Microstructures of SrBi2Ta2O9 materials investigated by TEM

CCAST“先进高分辨电子显微学—理论和应用”研讨会

作者： Xinhua Zhu, Jianmin Zhu, Shunhua Zhou, Qi Li, Zhiguo Liu, Naiben Ming national Laboratory of Solid State Microstructures, Department of Physics Nanjing University, Nanjing 210093

＜正＞ The microstructures of SrBi2Ta2O9 （SBT） materials including （001 ）-oriented single crystal and thin films with （001）-orientation, were investigated by transmission electron microscopy （TEM）. The 90°domain walls in SBT single crystal were identified by the 90°rotation relationship of the electron diffraction pattern about the [001] zone axis. They exhibit irregular configurations. The structural planar defects of anti-phase boundaries （APBs） in the SBT single crystal were also observed, which exhibit ribbon-like morphologies. Four-fold vertices formed by four APBs meeting together are observed as predominant singularities, and are explained by a four-state spin clock model. Some three-fold venices are also observed since both threefold and fourfold vertices are energetically allowed in the present model. Dissociation of grain boundary dislocations （GBDs） in the SBT thin films with （001）-orientation was also examined. Small-angle （8.2°） [001] tilt grain boundaries with a boundary plane close to the （110） plane exhibit partial GBDs separated by stacking faults. The energy of the stacking fault is evaluated to be 0.27-0.29 J/m2. The dissociated grain-boundary structures have twice the number of GBDs and interdislocation core channel width smaller than that Frank’s geometrical rule predicts. The edge dislocations at small-angle tilt grain boundary are deleterious to the leakage current of SBT films since the edge dislocation cores can provide pinning centers for the space charges in SBT films, resulting in high leakage current and poor fatigue-resistance characteristics.

关键词： SBT materials microstructures: TEM

Vascular and Morphogenetic Abnormalities Associated with Exposure of Cigarette Smoke Condensate during Chicken and Murine Embryogenesis

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Biomedical and Environmental Sciences 2010年第4期23卷 305-311页

作者： SOHAIL EJAZ AHMED EJAZ AMARA SOHAIL CHAE WOONG LIM Department of Clinical Neurosciences Neurology Unit Addenbrookes Hospital University of Cambridge District Headquarter Hospital Government Social Security Hospital Gujranwala Pakistan Biosafety Research Institute and College of Veterinary Medicine Chonbuk National University

Objective Embryonic movements （EM） and angiogenesis pathways are evolutionarily conserved mechanisms which are essential for proper embryonic development. Deviations in these processes by exposure to cigarette smoke condensate （CSC） may cause vascular and morphogenetic disorders. Methods Using chicken and mouse embryos, we have demonstrated the in vivo effects of CSC on EM, vascular development, and organogenesis. Results Examination of the CSC exposed chicken embryos revealed a significant reduction in EM, stunted growth, deviated pattern of blood vessels, hemorrhages, and localized necrosis. Likewise, mouse embryos that were exposed to CSC at E8.5 and E9.5 died between E11.5 and E12.5, respectively. These mouse embryos showed defects in morphogenesis and remodeling of the embryonic vasculature, while littermate controls showed normal development. Conclusion Cigarette smoking during pregnancy is fatal for growing embryos. CSC may induce the remodeling of embryonic vasculature, leading to various pathologies.

关键词： Angiogenesis Embryonic movements Cigarette smoke condensate Vascular remodeling

Numerical Simulation of Aluminum Colander’s HPDC Process with Back Pressure Conditions

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Numerical Simulation of Aluminum Colander’s HPDC Process wi...

第69届世界铸造会议暨2010中国铸造活动周

作者： ~* Cao Wenjiong Zhou Zhaoyao He Yi Wu Yuanbiao national engineering research center of near-shape forming for metallic materials South China University of Technology Guangzhou 510540 China

＜正＞Due to the flow behavior of molten metal is affected by the back pressure of mold residual air in high pressure die casting（HPDC） process,the back pressure conditions should be considered in order to simulate the HPDC process *** this study,an aluminum colander of automobile’s filling process in HPDC was calculated by combining the back pressure *** contribution of gas porosity between simulation and actual part were in agreement when back pressure conditions were *** results show that local back pressure can be controlled by coordinating the position of the vents further more flow behavior of molten metal can be *** optimization design was given upon the numerical *** changing the runner direction and relocating the venting gaps,the gas entrapments can be optimized and the porosity defects can be eliminated.

关键词： back pressure HPDC gas porosity numerical simulation

A simple method of synthesizing multi-wall carbon nanotubes/SnO core/shell nanostructure

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Rare Metals 2007年第S1期26卷 191-194页

作者： SUN Xue1),CHU Yi2),WANG Dawei3),DU Jinhong3),ZHANG Baoyou2),and WANG Fuping1)1) School of Science,Harbin Institute of Technology,Harbin 150001,China 2) School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China 3) Shenyang national Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China Harbin Inst Technol Sch Sci Harbin 150001 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China Chinese Acad Sci Inst Met Res Shenyang Natl Lab Mat Sci Shenyang 110016 Peoples R China

Multi-wall carbon nanotubes(MWNTs)/SnO core/shell nanosturcture was synthesized by a simple solution-based method,in which SnCl2 was solved in distilled water containing dispersed MWNTs,then stired,filtered and washed in ambient atmosphere,finally dryed in air at 90 ℃ for 6 *** MWNTs/SnO core/shell nanostructure was characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM).It is found that surface defects of MWNTs are necessary for the deposition of *** mechanism of the SnO nanocoating formation through the hydrolysis of SnCl2 in water(4SnCl_2+2H_2O-Sn_4(OH)2Cl_6+2HCl) was presented.

关键词： precipitate isothermal aging thermodynamic calculation phase diagram high nitrogen austenitic stainless steel

SIMULTANEOUS OPTIMIZATION OF ROBUST DESIGN WITH QUANTITATIVE AND ORDINAL DATA

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SIMULTANEOUS OPTIMIZATION OF ROBUST DESIGN WITH QUANTITATIVE...

2005年中国机械工程学会年会

作者： WU Fulchiang, YEH Chihao, LAI Rueilung (Dept. of Industrial Management, Vanung University, Taiwan, China Dept. of Industrial Engineering, national Taipei University of Technology, Taiwan, China)

＜正＞Many industries have employed the Taguchi method over the years to improve product or process performance. A real problem in a product or process usually has multiple quality characteristics. In confronting a product or process with multiple quality characteristics, it is difficult to determine the optimal control factor settings for each of the quality characteristics, as each usually varies according to different combinations of control factor settings. Several studies have presented approaches optimizing the multiple quantitative quality characteristics design. Due to the inherent nature of the quality characteristic or the convenience of the measurement technique and cost-effectiveness, the data observed in many experiments are ordinal data. Few published articles have focused primarily on optimizing the multiple quality characteristics involving quantitative and ordinal data. This paper presents a simple approach to optimizing this problem based on the quality loss function. A numerical example of the polysilicon deposition process for minimizing surface defects and achieving the target thickness in a very large-scale integrated circuit can demonstrate the proposed approach’s effectiveness.

关键词： Taguchi method multiple quality characteristics quantitative data ordinal data quality loss function

Nitride-based LEDs with improved ESD reliability

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Nitride-based LEDs with improved ESD reliability

The Eighth Chinese Optoelectronics Symposium

作者： Y. K. Su, S. C. Wei and S. J. Chang Institute of Microelectronics & Department of Electrical Engineering national Cheng Kung University, Tainan

GaN-based light emitting diodes (LEDs) with p-cap layers grown at various temperatures were fabricated. It was found that the LED with 900℃-grown p-cap layer could only endure negative 1100 V electrostatic discharge (BSD) pulses while the LED with 1040℃-grown p-cap layer could endure ESD pulses as high as negative 3500 V. It was also found that the ESD performances of the LEDs with 900 and 1040℃-grown p-cap layers were limited by the V-shape defects and the bonding pad design, respectively.

关键词： GaN LED growth temperature ESD V-defect

Atomic force microscopy studies of SrTiO_(3)(001)substrates treated by chemical etching and annealing in oxygen

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Science China(Physics,Mechanics & Astronomy) 2005年第4期48卷 459-468页

作者： WANG Xu1, FEI Yiyan1, LU Huibin1, JIN Kui-juan1, ZHU Xiangdong1,3, CHEN Zhenghao1, ZHOU Yueliang1 & YANG Guozhen1 1. Beijing national Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China 2. Department of Physics,University of California, Davis,California,USA Beijing national Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing China Department of Physics University of California Davis USA

The SrTiO3 (001) substrates treated by chemical etching in NH4F-buffered HF solution and annealing in oxygen ambient have been studied by an atomic force microscopy (AFM). The SrTiO3 substrates with TiO2-termineted and atomically smooth surfaces and single unit cell steps have been obtained. The surface morphologies of SrTiO3 substrates strongly depend on the treated conditions and the quality of the substrates.

关键词： SrTiO3, AFM, surface morphology, surface defects.

Technical study of Exhaust Valve Seal Surface Overlaying Based on Micro-plasma Arc Welding

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Technical Study of Exhaust Valve Seal Surface Overlaying Bas...

Fifth International Conference on Surface Engineering

作者： Y.H.Xiang Y.H.Lv D.Xia B.S.Xu national Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing China 100072

With high productivity,easy adjustment of welding parameters and free of weld defects,the micro-plasma arc welding technology is used successfully to remanufacture the exhaust valve of W615 *** ST6 Co alloy powder is selected as overlaying *** the geometry of deposited layer and economy,the processing parameters of overlaying is optimized,which include welding current,the rotate velocity of exhaust valve,the speed of feeding metal powder,*** current downslope method is developed to weaken the arc crater when arc *** microstructure characteristics of the weld are investigated by the optical microscope and X-ray *** micro-hardness and the internal stress of the deposited layer are also measured by the *** results show that the deposited layers have a fine dendrite structure at the top layer,and coarse columnar/cellular grain structures in the middle and at the bottom of the deposited *** fusion zone displays epitaxial grains structure,and the heat-affected zone within joint is not *** examinations do not detect any defects in the deposited layer or at the *** deposited layer possess a maximum hardness at the top layer with a slight decrease towards the bottom layer and fusion *** stress test show that there is low internal stress in deposited *** summary,The micro-plasma arc welding is a perfect welding method to remanufacture exhaust valve.

关键词： Exhaust valve Micro-plasma arc welding Cobalt alloy Microstructure remanufacture