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Research on Ultrafine Tungsten Carbide-Cobalt(WC-Co) Cemented Carbide Rods of Miniature Drills for Highly Integrated Printed Circuit Board(PCB)

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Journal of Materials science & technology 2005年第3期21卷 353-356页

作者： Xiaoliang SHI, Gangqin SHAO, Xinglong DUAN and Runzhang YUAN State Key Laboratory of Advanced technology for Materials Synthesis & Processing, Wuhan university of technology, Wuhan 430070, china Lab. of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Nanocrystalline tungsten carbide-cobalt (WC-Co) composite powders produced through spray thermal decomposition-continuous reduction and carburization technology were used to prepare φ3.25 mm×38 mm ultrafine tungsten carbide-cobalt (WC-Co) cemented carbide rods through vacuum sintering plus sinterhip technology. The microstructure, Vickers hardness, density and Rockwell A hardness (HRA), transverse rupture strength (TRS), saturated magnetization and coercivity force were tested. The results show that the average grain size of the sintering body prepared through vacuum sintering plus sinterhip technology was 430 nm; transverse rupture strength (TRS) was 3850 MPa; Vickers hardness was 1890 and Rockwell A hardness of sintering body was 93. High strength and high hardness ultrafine WC-Co cemented carbide rods used to manufacture printed circuit board (PCB) drills were obtained.

关键词： Nanocrystalline Composite powder Cemented carbide Rods

Research on Business Process Modeling and Business Process Service Based on Web Service

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Research on Business Process Modeling and Business Process S...

Study on the Complexity of the Bullwhip Effect

2010 IEEE 2nd Symposium on Web Society

作者： Feng Yan College of computer science and technology Jilin university Changchun,china technology Department Jilin Province Welfare Lottery Issue Center Changchun,china Shufen Liu College of computer science and technology Jilin university Changchun,china Zhilin Yao College of computer science and technology Jilin university Changchun,china

＜正＞This paper introduces the major process modeling methods and presents a new process modeling method based on Web *** method enables business processes to be released and called as Web services and provides support for access service *** the course of process execution,if an external service is required,the corresponding access service node will be added during process ***,it is difficult for operators to take part in workflow system by Web *** solve the problem,the author proposes a message management system in which the service provider and the requester communicate with each other via messages to realize manual participation.

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来源： cnki会议评论

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Journal of Electronic science and technology of china 2004年第3期2卷 86-91页

作者： LU Yingjin, TANG Yong, Tang Xiaowo (school of Management, university of Electronic science and technology of china Chengdu 610054 china) school of Management University of Electronic Science and Technology of China Chengdu 610054 China

Recent years have witnessed a rapid growth of interest in the study of the dynamic behavior of replenishment rules of bullwhip effect. We prove that bullwhip effect and butterfly effect share a same the self-oscillation amplifying mechanism that is the ordering decisions the supplier self-oscillation amplify the perturbations brought by the errors in the processing of retailers' demand information. This results as an explicit self-similar structure of the sensitivity of the system to the initial values duty to the nonlinear mechanism. In this paper, the causes process of the bullwhip effect is described as the internal nonlinear mechanism and study on the complexity of bullwhip effect for order-up-to policy under demand signal processing. The methodology is based on fractal and chaotic theory and allows important insights to be gained about the complexity behavior of bullwhip effect.

关键词： the bullwhip effect complexity theory order-up-to policy demand signal processing

The Research on Growth Temperature of Ge/Si Thin Films Grown by Magnetron Sputtering

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稀有金属材料与工程 2006年第S3期 564-566页

作者： Xu Mao~(1,2) Yingxia Jin~1 Zhenlai Zhou~2 Yu Yang~2 Xinghui Wu~2 Fuxue Zhang~1 (1.Research Centre of Sensor technology,Beijing Information technology Institute,Beijing 100101,china) (2.Department of Materials science and Engineering,Yunnan university,Kunming 650091,china)

The films of Ge and Si were grown on the substrate Si （100） by magnetron sputtering at 2.5 Pa Ar *** growth temperature of films was 100℃,250℃,400℃and 550℃.The structure and composition were analysised by Raman *** poly-crystal peak and crystal peak of Ge were observed in these *** results indicate that the single crystal film of Ge was prepared at the substrate temperature of 400℃.The peak of acoustic phonons of Ge was 98 cm-1and that of Si was 170 cm-1.

关键词： Ge/Si thin film Raman scattering growth temperature

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制备Mg基大块金属玻璃的特种铸造方法

特种铸造及有色合金 2004年第1期24卷 47-50页

作者：孙国元陈光刘平南京理工大学

叙述了制备方法对Mg基大块金属玻璃 (BMG)中的非晶相形成所起的至关重要的作用。介绍了国外近年来发展起来的几种制备Mg基BMG的特种铸造方法 ,包括金属型铸造法、低压铸造法、压铸法和挤压铸造法等 ,阐明了这些制备方法的工艺、工装设... 详细信息

叙述了制备方法对Mg基大块金属玻璃 (BMG)中的非晶相形成所起的至关重要的作用。介绍了国外近年来发展起来的几种制备Mg基BMG的特种铸造方法 ,包括金属型铸造法、低压铸造法、压铸法和挤压铸造法等 ,阐明了这些制备方法的工艺、工装设计、急冷原理以及最终的制备效果。指出金属型铸造时 ,在凝固的前 3 0s内 ,水冷铜型与无水冷铜型中的熔体冷却行为没有太大的区别 ;压铸时 ,熔体的淬火效率更加显著 ;挤压铸造能够制备出直径达 10mm的更大Mg65Cu15Y10Ag10 基BMG。Mg基BMG的制备方法的发展趋势是快速、简单、近终成形。

关键词： Mg基大块金属玻璃(BMG) 特种铸造工艺方法发展方向

Synthesis of hexagonal barium ferrite nanoparticle by sol-gel method

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Rare Metals 2006年第Z1期25卷 605-608页

作者： DONG Limin HAN Zhidong ZHANG Yaoming WU Ze ZHANG Xianyou College of Materials science and Engineering Harbin University of Science and TechnologyHarbin 150040China

M-type Ba hexaferrites were successfully synthesized by sol-gel *** synthesizing factors,such as pH value,citric acid/metal ion ratio,and dispersion agent were mainly *** and pure powders of BaFe_(12)O_(19)were optimally synthesized under the conditions of the pH value is 7 and citric acid/metal ion ratio is *** X-ray diffraction analysis demonstrates that no impurity is observed in the synthesized powders after presintered at 450℃and calcinated at 1100℃.SEM observations indicate that the size of the synthesized BaFe_(12)O_(19)powders is small and uniform *** can also be learned from SEM that the co-synthesizing sol-gel method can be in favor of the formation of finer particles.

关键词： sol-gel method M-type hexagonal ferrites preparation condition

BEM Simulation on Elastic Deformation of Oil Film Bearing in Low Speed and Heavy Load Rolling Mill

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武汉理工大学学报 2006年第S1期28卷 186-189页

作者： WANG Jianmei 1,2 ,ZHAO Chunjiang2,MA Lifeng1,HUANG Qingxue2 YANG Shichun1,YAO Jianbing2,SONG Chunhua1 (1.Taiyuan university of technology,Taiyuan 030024,china 2.Taiyuan university of science and technology,Taiyuan 030024,china) Taiyuan university of technology Taiyuan 030024China Taiyuan university of science and technology Taiyuan 030024China Taiyuan university of science and technology Taiyuan 030024China Taiyuan university of technology Taiyuan 030024China

The particularity of low speed and heavy load rolling loadcase makes the elastic deformation of radial journal bearing in rolling mill far more than that of bearing under general loadcase. Instead of deformation matrix algorithm based on conventional Hertz contact theory,3D boundary element method (BEM) is used to exactly calculate elastic deformation between contact bodies,the sample is given to calculate the elastic deformation of radial journal bearing in rolling mill. The deformation field and stress field of contact surfaces between bearing and roll are analyzed,as well as the influence of elastic deformation on lubrication properties of bearing.

关键词： journal bearing BEM elastic deformation lubrication properties

WORD SENSE DISAMBIGUATION BASED ON IMPROVED BAYESIAN CLASSIFIERS

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Journal of Electronics(china) 2006年第3期23卷 394-398页

作者： Liu Ting Lu Zhimao Li Sheng computer science ＆ technology school Harbin Institute of Technology Harbin 150001 China computer science ＆ technology school Harbin Engineering University Harbin 150001 China

Word Sense Disambiguation (WSD) is to decide the sense of an ambiguous word on particular context. Most of current studies on WSD only use several ambiguous words as test samples, thus leads to some limitation in practical application. In this paper, we perform WSD study based on large scale real-world corpus using two unsupervised learning algorithms based on ±n-improved Bayesian model and Dependency Grammar (DG)-improved Bayesian model. ±n-improved classifiers reduce the window size of context of ambiguous words with close-distance feature extraction method, and decrease the jamming of useless features, thus obviously improve the accuracy, reaching 83.18% (in open test). DG-improved classifier can more effectively conquer the noise effect existing in Naive-Bayesian classifier. Experimental results show that this approach does better on Chinese WSD, and the open test achieved an accuracy of 86.27%.

关键词： Word Sense Disambiguation (WSD) Natural Language Processing (NLP) Unsupervised learning algorithm Dependency Grammar (DG) Bayesian classifier

Empirical likelihood-based inference in a partially linear model for longitudinal data

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science china Mathematics 2008年第1期51卷 115-130页

作者： XUE LiuGen~(1+) & ZHU LiXing~2 1 College of Applied sciences, Beijing university of technology, Beijing 100022, china 2 Department of Mathematics, Hong Kong Baptist university, Hong Kong, china College of Applied sciences Beijing University of Technology Beijing China Department of Mathematics Hong Kong Baptist University Hong Kong China

A partially linear model with longitudinal data is considered, empirical likelihood to infer- ence for the regression coefficients and the baseline function is investigated, the empirical log-likelihood ratios is proven to be asymptotically chi-squared, and the corresponding confidence regions for the pa- rameters of interest are then constructed. Also by the empirical likelihood ratio functions, we can obtain the maximum empirical likelihood estimates of the regression coefficients and the baseline function, and prove the asymptotic normality. The numerical results are conducted to compare the performance of the empirical likelihood and the normal approximation-based method, and a real example is analysed.

关键词： partially linear model empirical likelihood confidence region longitudinal data 62G05 62G15 62G20