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Valance electron structure of carbide-diamond interface and catalytic mechanism for diamond synthesis under high-pressure and high-temperature

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Progress in Natural science:materials International 2006年第8期16卷 852-858页

作者： GONG Jianhong, XU Bin, YIN Longwei, QI Yongxin, LI Li, SU Qingcai and LI Musen (School of materials science and engineering, shandong University, jinan 250061, china department of materials science and engineering, shandong institute of architecture and technology, jinan 250014, china shandong engineering and technology Research Center of Super-hard materials, Zoucheng 273500, china) [a]School of materials science and engineering Shandong University Jinan China [b]shandong engineering and technology Research Center of Super-hard materials Zoucheng China [c]department of materials science and engineering Shandong Institute of Architecture and Technology Jinan China

The metallic films surrounding a synthetic diamond formed under high-pressure and high-temperature (HPHT) in the presence of Fe-based and Ni-based catalysts were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was showed that the carbide was the primary carbon source for the nucleation and growth of diamond. Based on the EET (empirical electron theory in solid and molecules) theory, the valence electron structure of interface between carbide (Fe3C, Ni3C, (Fe, Ni)3C) and diamond was calculated using the bonding length difference (BLD) method. The boundary criterion of Thomas-Fermi-Dirac-Cheng (TFDC): "the electron density being equal on the contacting surfaces of atoms" was applied to analyze the valence structure of carbide-diamond interface. The result based on the calculation valance electron structure is in good accordance with the experimental result. This study is very helpful to reveal the catalytic mechanism of diamond nucleation and growth and design the new catalyst for diamond synthesis.

关键词： synthetic diamond carbide catalytic mechanism valence electron theory interface.

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Influence of Heating Rate on Double Reversible Transformation in CuZnAlMnNi Shape Memory Alloy

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Rare Metals 2001年第2期20卷 117-120页

作者： Yujun Bai, Chengwei Lu, Xiangang Xu, Guili Geng, Longwei Yin (Mechanical department, shandong University of science and technology, jinan 250031, china institute of materials science and engineering, shandong University, jinan 250061, china) shandong Univ Sci & Technol Dept Mech Jinan 250031 Peoples R China shandong Univ Inst Mat Sci & Engn Jinan 250061 Peoples R China

The influence of heating rate on double reversible transformation in CuZnAlMnNi shape memory alloy was investigated by differential scanning calorimetry. It was found that rapid heating inhibits X -->M transformation but is favorable to the reverse martensite transformation, giving rise to the approach of the two transformation peaks. With the decrease of heating rate, the two transformation peaks separate gradually.

关键词： double reversible transformations heating rate CuZnAlMnNi shape memory alloy differential scanning calorimetry

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Gradual solution heat treatment of AlSiCuMg cast alloys

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Rare Metals 2003年第4期22卷 304-308页

作者： WANG Guiqing , BIAN Xiufang ,and ZHANG Junyan1) The Key Laboratory of Liquid Structure and Heredity of materials, Ministry of Education, shandong University, jinan 250061, china2) department of Material science and technology, shandong Architectural engineering institute, jinan 250014, china shandong University The Key Laboratory of Liquid Structure and Heredity of MaterialsMinistry of Education Jinan 250061

The microstructure characteristics of AlSiCuMg cast alloys were studied withdifferent Cu content and the gradual solution treatment by DSC, SEM, TEM and mechanical method. Themelting point of alpha (Al) + Si decreases and polynary eutectic phases with low melting point formwith increase of Cu content. Gradual solution treatment includes two steps: solution treating nearthe melting point of polynary eutectic phase to take it dissolve first, and then increasing solutiontemperature to take the remainder copper intermetallics dissolved into alpha (Al). Grain boundariesmelting can be avoided by gradual solution treatment, even the maximum solution temperature isabove final solidification point, and the age hardening response increases correspondingly

关键词： aluminum alloy gradual solution heat treatment differential scanningcalorimetry (DSC) polynary eutectic phase

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Wear Performance of Laser Surface Hardened GCr15 Steel

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Journal of Wuhan University of technology(materials science) 2010年第1期25卷 84-88页

作者：雷声 School of materials science and engineering Hefei University of Technology department of Electromechanical engineering Anhui Institute of Architecture and Industry

In order to assess the new tribological properties of laser surface hardened GCr15 steel, the wear resistance between specimens treated with laser and those of conventionally hardened under dry sliding conditions was compared. The change of wear mechanisms in laser hardened GCr15 resulted in a distinct difference in wear rates. The results showed that quenched zones not only had sufficient depth of hardening and higher hardness, but had more retained austenite and finer carbides because of a higher degree of carbide dissolution. Laser surface hardened GCr15 steel specimens exhibited superior wear resistance to their conventionally hardened specimens due to the effects of the microstructure hardening, high hardness and toughness. The wear mechanism for both the laser quenched layer and conventionally hardened layer was highly similar, generally involving adhesive, material transfer, wear-induced oxidation and plowing. When conventionally hardened block specimens rubbed against the laser hardened specimens, the surface of conventionally hardened block specimens was polished. The microstructural thermal stability was increased after laser surface treatment.

关键词： laser hardening dry sliding conditions GCr15 steel wear mechanisms

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The Compatibility of Polycarboxylate-Type Superplasticizers with Cement

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Journal of Wuhan University of technology(materials science) 2005年第3期20卷 95-98页

作者：李崇智 department of Civil engineering Beijing Institute of Civil Engineering and Architecture

Four polycarboxylate- type （ PC ） superplasticizers of different functional groups were used ; their dispersing and retaining behaviors were analyzed through ZETA potential measurement, mini-slump test of cement paste and performance test of concrete. The experimental results show that the dispersing and flow-retaining ability of PC was determined by two factors of anionic groups and nonionic groups ： the density of anionic groups - COO^- or - SO3^- acted on the electronic repulsive force. and the length and proportion of nonionic graft groups of PEO in PC chemical stracture affected the steric effect. The compatibility between PC superplasticizers and cement mainly depended on the type of PEO groups ; furtlwrmore, adding mineral powders is good to the compatibility for high performance concretes （ HPCs ）.

关键词： PC superplasticizers cement compatibility

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基于数字全息的图像置乱的研究

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山东大学学报（理学版） 2005年第5期40卷 93-96页

作者：戚文静赵敬山东建筑工程学院计算机科学与技术系山东济南250101 中华女子学院山东分院计算机系山东济南250001

基于用数字全息对图像进行置乱及复原的基本原理,提出了一种基于数字全息的图像置乱方法,并通过实验证明了本方法的置乱和复原效果.

关键词：数字全息图像置乱随机位相函数傅立叶变换

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Thermal Insulation and Strength of Autoclaved Light Concrete

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Journal of Wuhan University of technology(materials science) 2011年第1期26卷 132-136页

作者：杨若冲吴智深 School of Transportation Southeast University institute of Urban engineering science & technology Southeast University

The primary objective of this study was to develop an autoclaved light concrete （ALC） material with ultra-thermal insulation property and to investigate the relationship between its physical characteristics and mechanical properties. Through tests of dry bulk density and compressive strength, relationship of physical characteristics and mechanical properties of samples were studied, resulting in a material with ultra-thermal insulation property. Scanning electron microscope （SEM） and energy-dispersive X-ray spectroscopy （EDX） were applied to analyze the micro-morphology and elemental composition of samples. To identify the product phases, X-ray diffraction （XRD） was engaged. The test results showed that compressive strength and thermal coefficient were reduced with the increasing of aluminum powder within the mixtures. As a result the optimal thermal coefficient and compressive strength of samples were improved to 0.061 W/（m·k） and 1.2 MPa, respectively. SEM, EDX and XRD analyses showed that calcium silicate hydrate and tobermorite crystal were main resultant phases.

关键词： autoclaved light concrete ultra-thermal insulation microscopic appearance and phase analysis tobermorite crystal

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一种测试系统数字仿真器的设计

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济南大学学报（自然科学版） 2002年第3期16卷 238-240页

作者：夏传良山东建筑工程学院计算机科学与技术系山东济南250014

为了降低开发超大规模集成电路器件的测试程序的费用 ,缩短开发周期 ,给出了一种设计和开发测试系统仿真器的基本思想、结构组成及其功能。

关键词：测试系统数字仿真器设计测试程序功能模块脱机调试大规模集成电路电路测试

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一种CIMS仿真建模方法

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济南大学学报（自然科学版） 2003年第1期17卷 54-57页

作者：夏传良山东建筑工程学院计算机科学与技术系山东济南250014

针对一般CIMS系统中仿真建模所存在的覆盖面小和灵活性差的问题,本文中通过对一般计算机集成制造系统的功能层次的分析,采用分别处理的方法,提出了在CIMS应用系统中经营管理、生产制造和设备控制3个层次的仿真建模类型及其建模方法。

关键词： CIMS 仿真建模计算机集成制造系统经营管理生产制造设备控制柔性系统模型集成

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Effect of Activator and Curing Mode on Fly Ash-based Geopolymers

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Journal of Wuhan University of technology(materials science) 2009年第5期24卷 711-715页

作者：侯云芬 institute of Civil engineering and Traffic Beijing Institute of Civil Engineering and Architecture department of Material China University of Mining and Technology

The influences of concentration and modulus of sodium silicate solution and curing mode on the phase composition, microstructure and strength development in the geopolymers prepared using Class F fly ash were investigated. X-ray diffraction （XRD）, Fourier transform infrared spec-troscopy （FTIR） and MAS NMR were utilized. Results show that the compressive strength increases as sodium silicate solution modulus increases, but when modulus exceeds 1.4, the compressive strength decreases, and it decreases markedly while the modulus is greater than 2.0. The compressive strength was improved by the increase of sodium silicate solution concentration. When the concentration is 32%, the compressive strength reaches the maximum, then it reduces as concentration increasing. Elevated temperature can increase the strength of samples that synthesized from sodium silicate solution with 32% concentration and modulus 1.2. Compared to the strength of the sample cured at 50 ℃, the strength of the samples cured at 65 ℃ and 80 ℃ are higher at 1 d and 3 d, but the same at 7 d. At high temperature, prolonged curing time will decrease the strength. Long precuring at room temperature before application of heat is beneficial for strength development, and there is about 50% increase in strength of the samples cured at 1 d precuring and 2 d elevated temperature as compared to the strengths of the samples cured for 3 d at elevated temperatures or cured for 28 d at room temperature. The main product of reaction in the geopolymeric material is amorphous alkali aluminosilicate gel.

关键词： geopolymers fly ash activator elevated temperature

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