检索结果-南通市图书馆

Heat treatment of novel low-carbon multi-alloyed anti-wear marine steel

Progress in Natural Science:Materials International 2011年第3期21卷 254-261页

作者： Jing-hua JIANG~(1,2.,Qiu-yue WANG~1,Ai-bin MA~(1,2.,Jun SHI~1,Liu-yan ZHANG~1, Hui-dong YANG~(2.3.,Fu-min LU~2.Qi ZHOU~2.1.National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety, Hohai university,{2. 2.0098,China 2.College of Mechanics and Materials,Hohai university,{2. 2.0098,China 3.Department of Mechanical and Aerospace Engineering,North Carolina State university, Raleigh,North Carolina 2.695-7919,USA National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China College of Mechanics and Materials Hohai University Nanjing 210098 China Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh North Carolina 27695-7919 USA

A low-carbon anti-wear steel,multi-alloyed with Si-Cr-Mn-Al-Ni-Mo-（Nb,RE）,was designed for vane pumps of ships. The novel cast steel after various heat treatments was characterized by microstructure observations and mechanical properties measurement in order to achieve an optimal process correlated with good abrasive resistance for a long marine *** scanning calorimetry and hardness analyses deduced a complete austenitizing temperature of 1 000℃,based on the alloying element homogenization and defective structure elimination without grain *** optimal austempering process（austenitized at 1 000℃,quick cooled for holding at 3.0℃for 1.5 h and then air-cooled to room temperature） produced a uniform mixture structure of fine carbide-free aciculate bainites and few lath martensites,resulting in the tensile strength increase of 3.%and impact toughness increase of 50%compared with that of the as-cast *** abrasive wheel tests show that the austempered steel has good wear resistance with a mass-loss rate of 170 mg/（km·cm2. under applied load of 70 N in acidic *** new grade steel （containing anti-corrosion elements of Cr and rare earth） can find wide application in marine engineering,with further enhanced comprehensive properties via melting process improvement.

关键词： abrasive resistance carbide-free bainite marine steel mechanical performance heat treatment

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Spectral analysis of quasi-stationary sea surface topography from GRACE mission

引用

Science China Earth Sciences 2005年第11期48卷 2040-2048页

作者： ZHANG Zizhan1,2.& LU Yang1,3.1. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 43.077, China 2. Graduate School of the Chinese Academy of Sciences, Beijing 10003., China 3. Unite center for Astro-geodymics Research, Chinese Academy of Sciences, Shanghai 2.003., China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China Graduate School of the Chinese Academy of Sciences Beijing China Unite center for Astro-geodymics Research Chinese Academy of Sciences Shanghai China

During the last two decades satellite altimetry has offered an abundance of meas-urements of the sea surface resulting in the improvement of global mean sea surface height (MSSH) and marine geoid determination. On the other hand, with the launching of new genera-tion gravity satellites, some high accuracy long-wavelength gravity models are available. These breakthroughs give us a great opportunity for new estimation of quasi-stationary sea surface topography (QSST). In this paper, the new gravity model GGM01C derived from GRACE mission is briefly presented, and a new global high precision and high-resolution QSST is determined based on the GGM01C model and the global MSSH. The spectral features of the QSST esti-mated by GGM01C and EGM96 gravity model to degree/order 2.0 are discussed by spectral analysis. As a result, the QSST is mainly composed of long waves, medium waves partially and short waves scarcely, its power spectral structures are different between the zonal direction and the meridional direction, there are great differences between the two models, which maybe ex-plain why the ocean currents derived from the two gravity models by Tapley show different pat-terns.

关键词： quasi-stationary sea surface topography, mean sea surface height, GGM01, fast Fourier transform, spectral analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Syntheses,characterization,crystal structure and magnetic properties of copper(Ⅱ) α,β-unsaturated carboxylate complexes with trimethyl phosphate

引用

Chinese Science Bulletin 2001年第12期46卷 987-991页

作者： WANG Yaoyu, LIU Ping, SHI Qian, GAO Yici & SHI Qizhen1. Department of Chemistry, Northwest university, Xi’an 710069, China 2. Department of Chemistry, Wenzhou Teachers College, Wenzhou 3.1}003. China 3. Department of Chemistry, Lanzhou university, Lanzhou 73.000, China Department of Chemistry Northwest University Xi’an China Department of Chemistry Wenzhou Teachers College Wenzhou China Department of Chemistry Lanzhou University Lanzhou China

Two ternary complexes Cu2.4[OP(OCH3.3.2.(A represents CH2.CH-COO- and CH2.C(CH3.-COO-) have been synthesized, and elemental analyses, IR, ESR, electronic reflectance spectra and magnetic studies were carried out. The single crystal X-ray diffraction shows that Cu2.CH2.C(CH3.-COO]4[OP(OCH3.3.2.is triclinic, with space group P1, a = 1.0512.(13., b = 1.7559(5), c = 1.94479(3. nm, α =91.2.3.14)°,(β = 102.559(6)°,γ= 106.3.9(13.°, Z = 4 and R = 0.0668. Two copper(Ⅱ) atoms are bridged by four (a-methacrylate groups, and each copper(Ⅱ) atom is coordinated with a trimethyl phosphate molecule in the axial position, forming a distorted square pyramidal configuration. The symmetric center is between the two copper(Ⅱ) atoms, and the Cu-Cu bond distance is 0.2.098(6) nm. The Cu-Cu distance and magnetic studies suggest that there exist anti-ferromagnetic interactions between the two copper(Ⅱ) atoms.

关键词： copper(Ⅱ ) complex α β-unsaturated carboxylate trimethyl phosphate magnetic property crystal structure.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation Method of Web Site Structure Based on Web Structure Mining

引用

Wuhan university Journal of Natural Sciences 2003年第3A期8卷 791-796页

作者： Li Jun\|e 1 , Zhou Dong\|ru 2.1. Computer center,Wuhan university, Wuhan 43.072. Hubei, China 2. School of Computer,Wuhan university, Wuhan 43.072. Hubei,China Computer center Wuhan University Wuhan Hubei China School of Computer Wuhan University Wuhan Hubei China

The structure of Web site became more complex than before. During the design period of a Web site, the lack of model and method results in improper Web structure, which depend on the designer's experience. From the point of view of software engineering, every period in the software life must be evaluated before starting the next period's work. It is very important and essential to search relevant methods for evaluating Web structure before the site is completed. In this work, after studying the related work about the Web structure mining and analyzing the major structure mining methods (Page\|rank and Hub/Authority), a method based on the Page\|rank for Web structure evaluation in design stage is proposed. A Web structure modeling language WSML is designed, and the implement strategies for evaluating system of the Web site structure are given out. Web structure mining has being used mainly in search engines before. It is the first time to employ the Web structure mining technology to evaluate a Web structure in the design period of a Web site. It contributes to the formalization of the design documents for Web site and the improving of software engineering for large scale Web site, and the evaluating system is a practical tool for Web site construction.

关键词： web structure mining page\|rank web structure evaluation modeling language for web structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Risk analysis model for landslide mass of high slope in dam area

引用

Science China(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2.HE XianFeng3.4,WU ZhongRu1,2.& SU HuaiZhi1,2.1 College of Water Conservancy and Hydropower Engineering,Hohai {3.,nanjing 2.0098,China 2.National Engineering Research {2. of Water Resources Efficient Utilization and Engineering Safety,nanjing 2.0098,China 3.Yellow River Institute of Hydraulic Research,Zhengzhou 450003.China 4 Embankment Security Defect Prevention and Control Engineering Research {2. of MWR,Zhengzhou 450003.China College of Water Conservancy and Hydropower Engineering Hohai University Nanjing China National Engineering Research center of Water Resources Efficient Utilization and Engineering Safety Nanjing China Yellow River Institute of Hydraulic Research Zhengzhou China Embankment Security Defect Prevention and Control Engineering Research center of MWR Zhengzhou China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

引用

Science China Earth Sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2. DU Andao1, LU Jiren3. QU Wenjun1 & CHEN Jiangfeng2.1. National Research center of Geo{3., Beijing 10003., China 2. Laboratory for Earth Material Cycling, School of Earth and Space Sciences, {2. of Science and Technology of China, Hefei 2.002., China 3. Institute of Mineral Resource, Chinese Academy of Geological Sciences, Beijing 10003., China National Research center of Geoanalysis university of Science and Technology of China Chinese Academy of Geological Sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 83. ± 3. Ma, initial 187Os/188Os ratio of 0.2.9 ± 0.018 (MSWD = 1.7) and γOs = 13. ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3.. The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A formal model of fair exchange protocols

引用

Science in China(Series F) 2005年第4期48卷 499-512页

作者： QING Sihan1,2.3.& LI Gaicheng1,2.3.1. Engineering Research center for Information Security Technology, Institute of Software, Chinese Aca- demy of Sciences, Beijing 100080, China 2. Beijing Zhongke Ansheng Corporation of Information Technology, Beijing 100080, China 3. Graduate School of the Chinese Academy of Sciences, Beijing 10003., China Engineering Research center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing China Beijing Zhongke Ansheng Corporation of Information Technology Beijing China Graduate School of the Chinese Academy of Sciences Beijing China

Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability, etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack. Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

关键词： events local causal relation local temporal relation global relation exchanged item security goals.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simple Formula of β^+-Decay Half-Lives of Nuclei Far From β-Stable Line

引用

Communications in Theoretical Physics 2007年第12期48卷 1072-1080页

作者： ZHANG Xiao-Ping~1 REN Zhong-Zhou~(1,2.and ZHI Qi-Jun~1~1 Department of Physics,nanjing university,nanjing 2.0008,China~2.center of Theoretical Nuclear Physics,National Laboratory of Heavy-Ion Accelerator,Lanzhou 73.000,China Department of Physics Nanjing University Nanjing 210008 China center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator Lanzhou 730000 China

We generalize the formula of β^+-decay half-lives [***.C 78 (2.06) 0143.5] to include all availabledata of nuclei far from the β-stable line. Good agreement with experimental data is obtained by taking into accountthe even-odd (e-o) *** is shown that the e-o effect on β^+-deeay half-life is apparent for the allowed β^+-transition,whereas it is not apparent for the first and second forbidden *** demonstrates that the allowed β^+-transitionis more sensitive to the nuclear even-odd effect than the forbidden β^+-*** underlying physics is *** formula can be used to predict the β^+-decay half-lives of the nuclei far from β-*** is useful to experimentalphysicists for analyzing the data of β^+-decay.

关键词： β^+-decay half-lives formula even-odd effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inner Attitude Integration Algorithm Based on Fault Detection for Strapdown Inertial Attitude and Heading Reference System

引用

Chinese Journal of Aeronautics 2010年第1期23卷 68-74页

作者： Liu Jianye,Zhu Yanhua,Lai Jizhou,Yu Yongjun Navigation Research center,nanjing {2. of Aeronautics and Astronautics,nanjing 2.0016,China Navigation Research center Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

This article proposes a new inner attitude integration algorithm to improve attitude accuracy of the strapdown inertial attitude and heading reference system （SIAHRS） , which, by means of a Kalman filter, integrates the calculated attitude from the accelerometers in inertial measuring unit （IMU） , called damping attitudes, with those from the conventional IMU. As vehicle＇ s acceleration could produce damping attitude errors, the horizontal outputs from accelerometers are firstly used to judge the vehicle＇ s motion so as to determine whether the damping attitudes could be reasonably applied. This article also analyzes the limitation of this approach. Furthermore, it suggests a residual chi-square test to judge the validity of damping attitude measurement in real time, and accordingly puts forward proper information fusion strategy. Finally,the effectiveness of the proposed algorithm is proved through the experiments on a real system in dynamic and static states.

关键词： navigation strapdown inertial attitude and heading reference system inner attitude integration algorithm internal damping Kalman filter residual chi-square test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Half-lives and fine structure for the α decay of deformed even-even nuclei

引用

Science China(Physics,Mechanics & Astronomy) 2011年第S1期54卷 24-31页

作者： NI DongDong1,2.& REN ZhongZhou1,2.3.1Department of Physics, nanjing university, {3. {2. China 2.avli Institute for Theoretical Physics China, Beijing 100190, China 3.6} of Theoretical Nuclear Physics, National Laboratory of Heavy-Ion Accelerator, Lanzhou 73.000, China Department of Physics Nanjing University Nanjing China Kavli Institute for Theoretical Physics China Beijing China center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator Lanzhou China

The α-decay properties of well-deformed even-even nuclei are systematically calculated within the multichannel cluster model (MCCM). Instead of working in the WKB framework, the quasibound solution to the coupled Schro¨dinger equation is presented with outgoing wave boundary conditions, and the coupling potential is taken into full account in terms of the general quantum theories. The calculated α-decay half-lives are found to agree well with the experimental data with a mean factor of less than 2. The fine structure observed in α decay is also well reproduced by the four-channel microscopic calculation. Very strikingly, the MCCM can give relatively precise descriptions of the branching ratio to excited 4+ states, which is often overestimated in the usual WKB calculations. We expect it to be a significant development of theoretical models toward quantitative descriptions of α transitions to high-spin daughter states.

关键词： α decay half-lives cluster model coupled channel approach

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：