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The precipitation strengthening behavior of Cu-rich phase in Nb contained advanced Fe-Cr-Ni type austenitic heat resistant steel for USC power plant application

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Progress in Natural Science:Materials International 2012年第3期22卷 175-185页

作者： Cheng-yu Chi a, Hong-yao Yu b, Jian-xin Dong b, Wen-qing Liu c, Shi-chang Cheng d, Zheng-dong Liu d, Xi-shan Xie b a School of Metallurgical and Ecological Engineering, university of Science & Technology beijing, beijing 100083. {3. b School of Materials Science and Engineering, university of Science & Technology beijing, beijing 100083. {3. c Instrumental Analysis & Research Center, Shanghai university, Shanghai 200444, {3. d Central Iron and Steel Research Institute, beijing 100081, {3. [a] School of Metallurgical and Ecological Engineering University of Science & Technology Beijing Beijing 100083 China [b] School of Materials Science and Engineering University of Science & Technology Beijing Beijing 100083 China [c] Instrumental Analysis & Research Center Shanghai University Shanghai 200444 China [d] Central Iron and Steel Research Institute Beijing 100081 China

Copper has been used as a strengthening element in newly developed Fe-Cr-Ni type austenitic heat resistant steel for inducing Cu-rich phase precipitation to meet high temperature strength requirement for 600 ℃ Ultra Super-Critical (USC) coal fired power plants for many years. However, the precipitation behavior and strengthening mechanism of Cu-rich phase in these advanced austenitic heat resistant steels is still unclear. In order to understand the precipitation strengthening behavior of Cu-rich phase and to promote high strength austenitic heat resistant steel development, 18 Cr9 NiCuNb steel which is a Cu-added Nb contained advanced Fe-Cr-Ni type austenitic heat resistant steel has been selected for this study to be aged at 650 ℃ till to 10,000 h. Micro-hardness and room temperature tensile test were conducted after long-time aging. SEM, TEM, HRTEM and three dimensional atom probe (3.AP) technology accompanying with thermodynamic calculation have been used to investigate the Cu-rich phase precipitation behavior during 650 ℃ aging. The experimental results showed that Cu atoms can quickly concentrate in clusters at very early precipitation stage to form the fine nano-size Cu-rich "segregation areas" within less than 1 h at 650 ℃. With increasing aging time at 650 ℃ Cu atoms continuously concentrate to Cu-rich segregation areas (clusters) and simultaneously other kinds of atoms such as Fe, Cr and Ni diffuse away from Cu-rich segregation areas to austenitic matrix, and finally to complete the transformation from Cu-rich segregation areas to Cu-rich phase. However, there is only Cu atoms concentration but not crystallographic transformation from early stage of Cu-rich clusters forming to the final Cu-rich phase formation. Even the Cu atom becomes the main composed element after 500 h aging at 650 ℃ the Cu-rich phase still keeps coherent relationship with austenitic matrix. According the experimental results in this study, Cu-rich phase precipitation sequence which st

关键词： USC power plant Austenitic heat resistant steel Microstructure Cu-rich phase TEM 3.AP

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Improving Removal Efficiency of Organic Matters by Adding Phosphorus in Drinking Water Biofiltration Treatment

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Biomedical and Environmental sciences 2003年第1期16卷 29-39页

作者： XIN YU, XIAO-JIAN ZHANG, AND ZHAN-SHENG WANGDepartment of Environmental Science and Engineering, Tsinghua university, beijing 100084, china Department of Environmental Science and Engineering Tsinghua University 北京 100084

Objective To investigate phosphorus limitation and its effect on the removal efficiency of organic matters in drinking water biological treatment. Methods Bacterial growth potential (BGP) method and a pair of parallel pilot-scale biofilters were used for the two objectives, respectively. Results The addition of phosphorus could substantially increase the BGPs of the water samples and the effect was stronger than that of the addition of carbon. When nothing was added into the influents, both CODMn removals of the parallel biofilters (BF1 and BF2) were about 15%. When phosphate was added into its influent, BF1 performed a CODMn removal, 6.02 percentage points higher than the control filter (BF2) and its effluent had a higher biological stability. When the addition dose was 20μg. L-1, no phosphorus pollution would occur and there was a good linear relationship between the microbial utilization of phosphorus and the removal efficiency of organic matters. Conclusions Phosphorus was a limiting nutrient and its limitation was stronger than that of carbon. The addition of phosphate was a practical way to improve the removal efficiency of organic matters in drinking water biological treatment.

关键词： Drinking water Biofiltration Phosphorus Limiting nutrient Organic matters Biological stability

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The application of event-tree based approach in long-term crude oil scheduling

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Science china Chemistry 2010年第6期53卷 1445-1452页

作者： ZOU LaiXi,LI ChuFu,ZHANG Ming & HE XiaoRong Department of Chemical Engineering,Tsinghua university,beijing 100084,china 1. Department of Chemical Engineering Tsinghua University Beijing 100084 China

This paper addresses the problem of optimal operation in long-term crude oil scheduling,which involves unloading crude oil from vessels,transferring it to charging tanks and feeding it to the distillation *** application of a new approach for modeling and optimization of long-term crude oil scheduling is presented and the event-tree based modeling method that is very different from mathematical programming is *** approach is developed on the basis of natural language modeling and continuous time *** triggered rules,decomposition strategy,depth-first search algorithm and pruning strategy are adopted to improve the efficiency of searching the optimum *** approach is successfully applied to an industrial-size problem over a horizon of 4 weeks,involving 7 vessels,6 storage tanks,6 charging tanks,2 crude oil distillation units,and 6 crude oil *** CPU (AMD 3.00+,2.0GHz) solving time is less than 70 seconds.

关键词： crude oil scheduling modeling and optimization event-tree based depth-first search algorithm

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人白细胞抗原-G1对NK92效靶识别过程的影响

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生物化学与生物物理进展 2002年第6期29卷 904-909页

作者：田兴辉周建军方贞付娄黎明汪蕴丰美福中国科学院动物研究所生物膜与膜生物工程国家重点实验室北京100080 北京大学生命科学学院生物膜与膜生物工程国家重点实验室北京100871 北京师范大学生命科学学院北京100875

人白细胞抗原G (humanleukocyteantigen G ,HLA G)属非经典的主要组织相容性复合体 (majorhistocompatibilitycomplex ,MHC)Ⅰ类分子 ,为自然杀伤细胞 (naturalkiller,NK)抑制性受体的识别配体 ,可以向NK细胞传递抑制性信号 ,从而抑制N... 详细信息

人白细胞抗原G (humanleukocyteantigen G ,HLA G)属非经典的主要组织相容性复合体 (majorhistocompatibilitycomplex ,MHC)Ⅰ类分子 ,为自然杀伤细胞 (naturalkiller,NK)抑制性受体的识别配体 ,可以向NK细胞传递抑制性信号 ,从而抑制NK细胞的细胞毒作用 .为了研究HLA G对NK与靶细胞识别作用的影响机制 ,采用激光扫描共聚焦显微镜和流式细胞术对全长HLA G1的表达和功能进行了探讨 ,并对效靶识别过程中靶细胞 [Ca2 + ]i (胞内自由钙离子浓度 )进行了实时检测 .结果发现 ,全长的HLA G1表达于K5 6 2、JAR和CHO细胞的胞浆和胞膜上 ,它能够部分地抑制NK92的细胞毒作用 .NK92与CHO和GFP CHO细胞作用后 ,靶细胞 [Ca2 + ]i 出现了明显的升高 ,HLA G1的表达则抑制了靶细胞 [Ca2 + ]i的升高 .结果提示 :靶细胞[Ca2 + ]i 的升高是有效的细胞杀伤作用的必要条件 ,HLA

关键词：人白细胞抗原-G1 NK92 效靶识别过程影响胞内钙离子免疫抑制

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Apparent Activation Energy of Concrete in Early Age Determined by Adiabatic Test

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Journal of Wuhan university of Technology(Materials Science) 2007年第3期22卷 537-541页

作者：王甲春阎培渝 Department of Civil Engineering Nanjing University of Aeronautics and Astronautics

The apparent activation energy of concrete in early age was determined by adiabatic temperature rise test with different initial temperatures. The influence of mineral admixtures such as fly ash, slag and silica fume on the apparent activation energy of concrete was investigated. The equivalent age that expresses the maturity of concrete was calculated to evaluate the cracking risk of concrete in structures. The results reveal that a substitution of 20% fly ash for Portland cement obviously decreases the apparent activation energy of concrete, however, a substitution of 10% silica fume for Portland cement increases the apparent activation. Finite element method analysis of a simulating concrete wall shows that the concrete containing 20% fly ash has the lowest cracking risk.

关键词： mineral admixtures apparent activation energy equivalent age cracking risk

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非完整力学系统的非Noether守恒量——Hojman守恒量

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物理学报 2004年第3期53卷 666-670页

作者：罗绍凯梅凤翔浙江工程学院数学力学与数学物理研究所北京理工大学理学院北京100081

研究非完整力学系统的非Noether守恒量———Hojman守恒量 .在时间不变的特殊Lie对称变换下 ,给出非完整力学系统的Lie对称性确定方程、约束限制方程和附加限制方程 ,得到相应完整系统的Hojman守恒量以及非完整系统的弱Hojman守恒量和强... 详细信息

研究非完整力学系统的非Noether守恒量———Hojman守恒量 .在时间不变的特殊Lie对称变换下 ,给出非完整力学系统的Lie对称性确定方程、约束限制方程和附加限制方程 ,得到相应完整系统的Hojman守恒量以及非完整系统的弱Hojman守恒量和强Hojman守恒量 .

关键词：分析力学非完整系统 Lie对称性非Noether守恒量 Hojman守恒量对称变换约束限制方程附加限制方程

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THE EXISTENCE OF OVERLARGE SETS OF IDEMPOTENT QUASIGROUPS

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Acta Mathematica Scientia 2004年第2期24卷 165-170页

作者：常彦勋雷建国 DepartmentofMathematics BeijingJiaotongUniversityBeijing100044China

A idempotent quasigroup (Q, o) of order n is equivalent to an n(n-1)×3.partial orthogonal array in which all of rows consist of 3.distinct elements. Let X be a (n+1)-set. Denote by T(n+1) the set of (n+1)n(n-1) ordered triples of X with the property that the 3.coordinates of each ordered triple are distinct. An overlarge set of idempotent quasigroups of order n is a partition of T(n+1) into n+1 n(n-1)×3.partial orthogonal arrays A_x, x∈X based on X\{x}. This article gives an almost complete solution of overlarge sets of idempotent quasigroups.

关键词： Pairwise balanced design conjugate invariant subgroup overlarge set of idempotent quasigroups

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Experimental studies on removal of carbon dioxide by aqueous ammonia fine spray

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Science china(Technological sciences) 2010年第1期53卷 117-122页

作者： NIU ZhenQi,GUO YinCheng & LIN WenYi Department of Engineering Mechanics,School of Aerospace,Tsinghua university,beijing 100084,china 1. Department of Engineering Mechanics School of Aerospace Tsinghua University Beijing 100084 China

Experimental studies on carbon dioxide capture in a spray scrubber were carried *** spray of aqueous ammonia was used as CO2 *** of different operating and design parameters on CO2 removal efficiency including concentration of aqueous ammonia,liquid flow rate,total gas flow rate,initial temperature and concentration of carbon dioxide were investigated.

关键词： carbon dioxide aqueous ammonia absorption removal efficiency fine spray

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Measurement of Mean Burst Period in WallTurbulence by Wavelet Analysis

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Li LI Chunxiao XU Zhaoshun ZHANG and Guialang CUI(Department of Engineering Mechanics, Tsinghua university, beijing 100084, china) Department of Engineering Mechanics Tsinghua University Beijing 100084 China

IntroductionInwallturbulence,theejectionoflow-speedfluidfromthewallandthesweepofth***urst,andwhentheflowisbursting,therealwaysea... 详细信息

IntroductionInwallturbulence,theejectionoflow-speedfluidfromthewallandthesweepofth***urst,andwhentheflowisbursting,therealwaysea...

关键词： turbulence burst phenomena wavelet analysis

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CRYSTALLIZATION AND MAGNETIC PROPERTIES OF AMORPHOUS Nd_6Fe_(81)B_(13.ALLOY

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Acta Metallurgica Sinica(English Letters) 1991年第8期4卷 98-102页

作者： GU Benxi ZHAI Hongru Nanjing university,Nanjing,chinaSHEN Baogen Institute of Physics,Academia Sinica,beijing,china Nanjing Univ Nanjing China

The magnetic properties and the crystallization and its influence on the magnetic and struc- tural properties for rapidly quenched amorphous Nd_6Fe_(81)B-(13. alloy have been *** low temperature magnetic properties,the Curie temperature and the crystallization behavior are discussed.A small addition(6at.-%)of Nd in amorphous Fe-B alloys increases largely the crystallization temperature T_x but causes a decrease of the Curie temperature Tc·A new phase was observed in the sample annealed at 873.K.

关键词： amorphous alloy magnetic properties crystallization structure

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