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A Large-Scale Study of Failures on Petascale Supercomputers

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Journal of Computer Science & Technology 2018年第1期33卷 24-41页

作者： Rui-Tao Liu zuo-Ning chen State Key Laboratory of Mathematical Engineering and Advanced Computing Wuxi 213215 China National Research Center of Parallel Computer Engineering and Technology Beijing 100190 China

With the rapid development of supercomputers, the scale and complexity are ever increasing, and the reliability and resilience are faced with larger challenges. There are many important technologies in fault tolerance, such as proacrive failure avoidance technologies based on fault prediction, reactive fault tolerance based on checkpoint, and scheduling technologies to improve reliability. Both qualitative and quantitative descriptions on characteristics of system faults are very critical for these technologies, This study analyzes the source of failures on two typical petascale supercomputers called Sunway BlueLight （based on multi-core CPUs） and Sunway TaihuLight （based on heterogeneous manycore CPUs）. It uncovers some interesting fault characteristics and finds unknown correlation relationship among main components＇ faults. Finally the paper analyzes the failure time of the two supercomputers in various grains of resource and different time spans, and builds a uniform multi-dimensional failure time model for petascale supereomputers.

关键词： petascale supercomputer fault characteristic correlation relationship multi-dimension failure time model

Microstructures and mechanical properties of a new titanium alloy for surgical implant application

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 185-191页

作者： Jun Li Lian Zhou zuo-chen Li School of Materials Engineering Shanghai University of Engineering Science Shanghai 201620 China Northwest Institute for Nonferrous Metal Research Xi＇an 710016 China

A new titanium alloy Ti12.5Zr2.5Nb2.5Ta（TZNT） for surgical implant application was synthesized and fully annealed at 700℃for 45 *** microstructure and the mechanical properties such as tensile properties and fatigue properties were *** results show that TZNT mainly consists of a lot of lamellaα-phase clusters with different orientations distributed in the originalβ-phase grain boundaries and a small amount ofβphases between the lamella a *** alloy exhibits better ductility,lower modulus of elasticity,and lower admission strain in comparison with Ti6A14V and Ti6A17Nb,indicating that it has better biomechanical compatibility with human *** fatigue limit of TZNT is 333 MPa,at which the specimen has not failed at 10^7 cycles.A large number of striations present in the stable fatigue crack propagation area,and many dimples in the fast fatigue crack propagation area are observed,indicating the ductile fracture of the new alloy.

关键词： titanium alloy surgical implant microstructure mechanical properties fatigue

Lessons Learned from Optimizing the Sunway Storage System for Higher Application I/O Performance

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Journal of Computer Science & Technology 2020年第1期35卷 47-60页

作者： Qi chen Kang chen zuo-Ning chen Fellow CCF Wei Xue Xu Ji Bin Yang Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China Chinese Academy of Engineering Beijing 100088China National Supercomputing Center in Wuxi Wuxi 214100China School of Software Shandong UniversityJinan 250101China

It is hard for applications to make full utilization of the peak bandwidth of the storage system in highperformance computers because of I/O interferences,storage resource misallocations and complex long I/O *** performed several studies to bridge this gap in the Sunway storage system,which serves the supercomputer Sunway *** locate these issues and connections between them,an end-to-end performance monitoring and diagnosis tool was developed to understand I/O behaviors of applications and the *** the help of the tool,we were about to find out the root causes of such performance barriers at the I/O forwarding layer and the parallel file system *** application-aware I/O forwarding allocation framework was used to address the I/O interferences and resource misallocations at the I/O forwarding layer.A performance-aware data placement mechanism was proposed to mitigate the impact of I/O interferences and performance variations of storage devices in the ***,applications obtained much better I/O *** the process,we also proposed a lightweight storage stack to shorten the I/O path of applications with N-N I/O *** paper summarizes these studies and presents the lessons learned from the process.

关键词： high performance computing I/O interference parallel file system performance optimization resource misallocation

Post-exascale supercomputing:research opportunities abound

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Frontiers of Information Technology & Electronic Engineering 2018年第10期19卷 1203-1208页

作者： zuo-ning chen Jack DONGARRA Zhi-wei XU Chinese Academy of Engineering Electrical Engineering and Computer Science Department University of Tennessee Institute of Computing Technology Chinese Academy of Sciences

Exascale supercomputing refers to the scientific research efforts and activities to build and use supercomputers that can perform scientific computing at the speed of exaflops,or 10^(18) floating-point(64-bit)operatio... 详细信息

关键词：计算研究机科学研究浮点操作

Separation of growth-stimulating peptides for Bifidobacterium from soybean conglycinin

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World Journal of Gastroenterology 2005年第37期11卷 5801-5806页

作者： Wei-Yong zuo Wei-Hua chen Si-Xiang Zou Key Laboratory of Animal Physiology and Biochemistry Ministry of Agriculture College of Veterinary Medicine Nanjing Agricultural University Nanjing 210095 Jiangsu Province China

AIM： To isolate and identify the soybean conglycinin peptides that selectively stimulates the growth of bifidobacteria in vitro, and to investigate the effect of soybean conglycinin peptides on intestinal ecosystem in vivo. METHODS： Soybean conglycinin was purified from soybean seeds by gel filtration （Sepharose-CL-6B）. These proteins were submitted to hydrolysis by pepsin. Several growth-stimulating peptides for bifidobacteria were isolated chromatographically from pepsin hydrolysis of soybean conglycinin and identified by means of matrixassisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）. Parallel to in vitro study, in vivo experiments with soybean conglycinin peptides were performed in mice. Ninety male KM mice were randomly assigned into five groups of 16 mice each, and each group was administered for 21d intragastrically with physiological saline （control）, conglycinin, pepsin-treated conglycinin （PTC）, the most active fraction which isolated from pepsin-treated conglycinin （P2-PTC） and HCl-full hydrolysis of conglycinin （HCl-FHC）, respectively. Intestinal microflora were evaluated by standard microbiologic methods and biochemical assays of cecal content samples after treatment. RESULTS： The results showed that the peptides which were isolated from soybean conglycinin could stimulate the growth of bifidobacteria in vitro, and the molecular mass of purified peptides with MALDI-TOF-MS ranged from 693.32 to 1829.55. Compared with control group, in vivo experiments showed that P2-PTC group decreased cecal pH （7.08±0.08 vs7.21±0.09, P〈0.05） and enterococcicounts （5.38±0.26 log10CFU/g vs 5.78±0.19 log10CFU/g, P〈0.05）, significantly increased sIgA level （172.08±35.40 ng/g vs 118.27±33.93 ng/g, P〈0.01） and β-galactosidase activity （1.28±0.23 U/g vs 1.82±0.58 U/g, P〈0.05） CONCLUSION： The results have shown that conglycinin is good source for enzyme-mediated production of peptides which stimulate the growth of bifidobacteria. These peptid

关键词： Conglycinin pepsin peptides bifidobacteria

Fracture Network Volume Fracturing Technology in High-temperature Hard Formation of Hot Dry Rock

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Acta Geologica Sinica(English Edition) 2021年第6期95卷 1828-1834页

作者： chen zuo XU Guoqing ZHOU Jian LIU Jiankun SINOPEC Research Institute of Petroleum Engineering Beijing 102206China

It is more difficult for a hot dry rock to form a fracture network system than shale due to its special lithology, physical and mechanical properties under high temperature. The essential characteristics, rock mechanics and in-situ stress characteristics of a hot rock mass have been systematically studied by means of laboratory tests and true tri-axial physical simulation. The fracture initiation and propagation characteristics under different geological and engineering conditions are physically simulated, and the main controlling factors for the formation of a complex fracture network are revealed. The technology of low displacement for enhancing thermal cracking, gel fluid for expanding fracture and variable displacement cyclic injection for increasing a fracture network has been applied in the field, and good results have been achieved. Microseismic monitoring results demonstrate that complex fractures were formed in the field test, and the stimulation volume for heat exchanging reaches more than 3 million cubic meters. The research results play an important role in the stimulation technology of an enhanced geothermal system(EGS) and realize a breakthrough for power generation.

关键词： hot dry rock granite fracture network natural fractures thermal cracking cyclic injection volume stimulation Gonghe Basin

Relation of hepatic EROD activity and cytochrome P4501A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

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Journal of Environmental Sciences 2008年第1期20卷 101-104页

作者： WANG Yun ZHENG Ronghui zuo Zhenghong chen Yixin WANG Chonggang Key Laboratory of the Ministry of Education for Cell Biology and Tumor Cell Engineering School of Life Sciences Xiamen University Xiamen 361005 China.

This study was designed to investigate the in vivo effects of benzo[a]pyrene （BaP） on hepatic ethoxyresorufin-O-deethylase （EROD） activity and its correlation with cytochrome P4501A （CYP1A） protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP （10, 100, 1000 ng/L, respectively） or were treated with intraperitoneal injections of BaP （0.5, 1, 5, 10 mg/kg, respectively） every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second intraperitoneal injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites （100 ng/L） was much lower than that with reference to EROD activity （1000 ng/L）. The results suggest that biliary polycyclic aromatic hydrocarbon （PAH） metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.

关键词： BaP BaP metabolites EROD activity CYP1A protein Sebastiscus marmoratus

Green fabrication of nickel-iron layered double hydroxides nanosheets efficient for the enhanced capacitive performance

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Green Energy & Environment 2022年第5期7卷 1053-1061页

作者： Yuchen Wang zuo chen Man Zhang Yaoyu Liu Huixia Luo Kai Yan School of Environmental Science and Engineering Sun Yat-sen UniversityGuangzhou510275China Key Lab of Polymer Composite&Functional Materials School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou510275China Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology Guangzhou510275China

Rational synthesis of robust layered double hydroxides(LDHs) nanosheets for high-energy supercapacitors is full of ***,we reported an ultrasonication-assisted strategy to eco-friendly fabricate NiFe-LDHs nanosheets for the enhanced capacitive *** experimental results combined with different advanced characterization tools document that the utilization of ultrasonication has a profound effect on the morphology and thickness of the as-obtained NiFe-LDHs,alternatively affecting the capacitive *** shows that NiFe-LDHs nanosheets prepared with 2-h ultrasonic treatments display the exceptional capacitive performance because of the synergetic effect of ultrathin thickness,large specific surface area,and high mesoporous *** maximum specific capacitance of Ni_(3) Fe_(1)-LDHs nanosheets with the thickness of 7.39 nm and the specific surface area of 77.16 m~2 g^(-1) reached 1923 F g^(-1),which is competitive with most previously reported *** addition,the maximum specific energy of the assembled NiFe-LDHs//AC asymmetric supercapacitor achieved 49.13 Wh kg^(-1) at400 W kg^(-1).This work provides a green technology to fabricate LDHs nanosheets,and offers deep insights for understanding the relationship between the morphology/structure and capacitive behavior of LDHs nanosheets,which is helpful for achieving high-performance LDHs-based electrode materials.

关键词： performance double sheets

Progress of the RF negative hydrogen ion source for fusion at HUST

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Plasma Science and Technology 2022年第12期24卷 149-156页

作者： chen zuo Peng chen Zengshan LI Jinghan YANG Fei SONG Dezhi chen State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People's Republic of China

Huazhong University of Science and Technology has developed an experimental setup of a radio frequency(RF) driven negative hydrogen ion source,to investigate the physics of production and extraction of the H^(-)ions for neutral beam injection in nuclear fusion *** main design parameters of the ion source are:RF power ≤40 kW;extraction voltage ≤10kV;accelerator voltage ≤20 *** paper gives an overview of the progress of the ion source with particular emphasis on some *** RF driver and source plasma are analyzed and optimized in terms of impedance matching,plasma characteristics and power *** regard to the simulation analysis,a plasma model based on the particle-in-cell method and a beam trajectory model considering beam stripping loss are developed to investigate the plasma and negative ions transport inside the ion ***,a collisional radiative model of H and H2is built for plasma optical diagnosis.

关键词： negative ion sources radio frequency(RF) particle-in-cell(PIC) beam simulation