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2014’中国溶胶—凝胶学术研讨会暨国际论坛

作者： Fei He Mingwei Li Xiaodong He Chao Sui Center for Composite Materials Harbin Institute of Technology Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology National Key Laboratory for Precision Hot Processing of Materials Harbin Institute of Technology

Aerogels are a low-density,porous,non-crystalline,nanometer solid material,whose continuous network structures can be controlled and tialored by varying the amount of reactants,catalyst and *** fragility and brittleness,however,are the major drawbacks,which restrict their application in effective ***,the flexibility of aerogels becomes more attractive in the present *** is the most abundant resource in the world and microfibrillated cellulose can be made from all kinds of plants[1].But cellulose is an insoluble material,which is a main problem in the composite course using cellulose as an adulterant[2].Our work focuses on the preparation of new organic/inorganic hybrid silica-cellulose aerogels by the sol-gel process and supercritical *** sols were prepared by dissolving Methyltrimethoxysilane（MTMS）in acid aqueous solution by using dimethyl sulfoxide（DMSO）as solvent to suppress phase *** nanowhiskers were extracted by the acid hydrolysis of cotton wool in a 64 wt.%aqueous HSO solution and then dispersed into silica sols under the help of *** silica-cellulose aerogels of different cellulose contents were obtained by two-step acid-base sol-gel method and supercritical *** electron microscopy（SEM）,Fourier transform infrared（FT-IR）spectra and X-ray diffraction（XRD）analysis were used to investigate the microstructure and the connection of chemical *** porous structure and specific surface was measured by nitrogen *** action of cellulose in hybrid aerogels was discussed.

关键词： silica-cellulose aerogels flexible sol-gel preparation porous materials DMSO

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Synthesis and Characterization of the Copper Complex Pearlescent Pigment

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Journal of Harbin Institute of technology(New Series) 2013年第1期20卷 42-45页

作者： Yong-Tao Yao Guo-Jun Yan Science and Technology on Advanced Composites in Special Environments Laboratory Harbin Institute of Technology

The copper complex pearlescent pigment was synthesized by the two steps diazotization and azo coupling. The crystal phases and the microstructure of the copper complex pearlescent pigment powders were characterized through a combination of DSC, FT-IR and SEM analysis after purification. The results indicated that the copper complex pearlescent pigment has very good thermal stability and the fine particle size is uniformly distributed, and the average grain size is around 15 μm.

关键词： pearlescent pigment copper complex pigment azo coupling

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Reaction mechanism of self-propagating magnesiothermic reduction of ZrB_2 powders

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Rare Metals 2013年第4期32卷 408-413页

作者： Yong-Ting Zheng Hong-Bo Li Zhong-Hai Xu Jing Zhao Pan Yang Science and Technology on Advanced Composites in Special Environments Laboratory Harbin Institute of Technology Materials Engineering Department North China Institute of Aerospace Engineering

Fine zirconium diboride （ZrB2） powders with high purity were successfully prepared by combustion synthesis through magnesiothermic reduction process in Mg-B2O3-ZrO2 system. The reaction mechanism was investigated by differential thermal analysis and quenching experiment. The results show that the whole magnesio-thermic reduction process includes three stages： first, molten B2O3 and Mg formed above the temperature of 650 ℃, and glassy B2O3 and solid ZrO2 particles were coated on the surface of the molten Mg; thus, the hollow balls can be formed when the molten Mg was exuded under capillary function. Second, ZrO2 particles reacted with molten Mg to form Zr and MgO with dissolution-precip-itation mechanism, which released a large amount of heat to induce the diffusion reaction between B203 and Mg to form B and MgO. Last, Zr reacted with B to form ZrB2 grains. The preparation of ZrB2 by self-propagating syn-thesis in Mg-B2O3-ZrO2 system is a solid-liquid-liquid reaction.

关键词： Reaction mechanism Magnesiothermicreduction Zirconium boride Self-propagating synthesis

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Fabrication and structural characteristic of flexible organic/inorganic hybrid silica-cellulose aerogels

Fabrication and structural characteristic of flexible organi...

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2014中国溶胶-凝胶学术研讨会暨国际论坛

作者： Fei He Mingwei Li Xiaodong He Chao Sui Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150080 National Key Laboratory for Precision Hot Processing of Materials Harbin Institute of Technology Harbin 150001 Center for Composite Materials Harbin Institute of Technology Harbin 150080

关键词： silica-cellulose aerogels flexible sol-gel preparation porous materials DMSO

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Microstructure characterization from X-ray micro-tomography and equivalent mechanical properties of carbon matrix of 4D in-plane carbon/carbon composites

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Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica 2013年第SUPPL.期30卷 193-198页

作者： Xu, Chenghai Xu, Kai Song, Leying Xu, Desheng Meng, Songhe Science and Technology of Advanced Composites in Special Environments Laboratory Harbin Institute of Technology Harbin 150001 China

The present work uses high-resolution X-ray tomography to measure inner structures characteristics of multi-directional braided carbon/carbon composites so as to obtain probability density function of size distribution of microscopic structure in matrix. Based on the theory of non-homogeneous equivalent inclusion, it is easy to establish mathematical analysis model of effective elastic properties of carbon matrix. Strength theory of porous medium is adopted to deduce strength calculation model. The study shows that there are many holes which are randomly distributing and anisotropic. The size of these holes fit normal distribution. Specifically, they are within the range of 20 μm to 200 μm. We work out the equivalent stiffness and strength by introducing the statistical regularities of characteristics of carbon matrix into equivalent mechanical model .It is clear that find out that the hole can impact mechanical properties of matrix significantly .And when the hole fit normal distribution, the stiffness and strength of matrix can also fit normal distribution.

关键词： Microstructure

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A numerical algorithm for eliminating the singular stiffness matrix of membrane wrinkling 54

A numerical algorithm for eliminating the singular stiffness...

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54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

作者： Wang, C.G. Lan, L. Liu, Y.P. Zhang, L. Tan, H.F. Center for Composite Materials Harbin Institute of Technology Harbin 150001 China National Key Laboratory of Science and Technology Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150080 China

ISBN: (数字)9781624102233

ISBN: (纸本)9781624102233

A novel wrinkling algorithm-Modified Singular Displacement Component (MSDC) method is proposed to eliminate the singularity of the stiffness matrix of membrane wrinkling. Three keys in MSDC are then considered in the numerical scheme by using the stabilized Newton-Raphson iteration and the disturbing forces. The numerical solution scheme is further introduced into ANSYS post-buckling simulation codes to complete the integrated wrinkling calculation by applying the Direct Disturbing Force (DDF) technique. The wrinkling formation and evolution of a rectangular membrane under shearing are simulated by using the proposed wrinkling algorithm. The validation and accuracy of the proposed wrinkling algorithm are verified by the wrinkling experiment based on the photogrammetry. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Stiffness matrix

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A new dynamic reanalysis method for the composite structures 19

A new dynamic reanalysis method for the composite structures

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19th International Conference on Composite Materials, ICCM 2013

作者： Xu, Z.H. Lv, X.J. Liu, Z. Dai, C.Q. Jiao, W.C. Yang, F. Hao, L.F. Wang, R.G. He, X.D. National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin150080 China Network and Information Center Harbin Institute of Technology Harbin150080 China

In this paper, a new dynamic reanalysis method for composite structures is presented. First we construct an iterative format on the basis of the matrix perturbation theory. By introducing a pair of initial eigensolution, we can obtain the natural vibration mode of the modified composite structure, and then use the Rayleigh quotient to compute the corresponding natural frequency. In this way, the computation accuracy can be greatly improved. Finally, a numerical example of composite laminate is included to demonstrate the validity of the proposed method. © QinetiQ Ltd 2013.

关键词： Composite structures Dynamic reanalysis Iteration Natural frequency

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Degradation in strength of silica fiber-reinforced phenolic resin composite under heat flux environment

Degradation in strength of silica fiber-reinforced phenolic ...

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13th International Conference on Fracture（ICF13）

作者： Jun Liang Shengbo Shi Linjie Li Science and Technology on Advanced Composites in Special Environments Key Laboratory Harbin Institute of Technology

The main peculiarity of resin matrix composites is the presence of irreversible physico-chemical processes of ablation,when the composite mass ***,the microstructure and mechanical properties of the material may be ch... 详细信息

关键词： Degradation in strength of silica fiber-reinforced phenolic resin composite under heat flux environment

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Some new signature schemes and secret sharing schemes based on the Gröbner basis cryptosystems

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Journal of Computational Information Systems 2013年第13期9卷 5133-5140页

作者： Li, Hengyan Chang, Shuizhen Xu, Zhonghai Mathematics and Information Science College North China University of Water Resources and Electric Power Zhengzhou 450011 China Mathematics and Information Science College Luoyang Normal University Luoyang 471022 China Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University Changchun 130012 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of Technology Harbin 150080 China

In this paper, we introduce some new signature schemes and secret sharing schemes from the known Gröbner basis cryptosystems. Then, we discuss the issues related to the security of these schemes. Finally, we draw... 详细信息

关键词： Cryptography

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Irradiation effect of space particle on sapphire single crystal for optical window material

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Rengong Jingti Xuebao/Journal of Synthetic Crystals 2013年第7期42卷 1309-1314页

作者： Zhang, Yu-Min Ke, Rui Han, Jie-Cai Zhou, Yu-Feng Yin, Zhong-Wei Li, Kai National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin 150080 China Engineering and Technical Training Center for Daqing Oilfield Daqing 163255 China

As a kind of optical window material, sapphire single crystal (α-Al2O3) is irradiated by different kinds of rays and the ion currents when served in the space environment inevitably, therefore, the properties will be decreased. The optical properties and structure changes in sapphire single crystal (α-Al2O3) optical window caused by electron, patron and integrative irradiation were discussed in order to study the properties. The surface roughness, surface accuracy and the transmission before and after the irradiation were characterized. According to the AFM testing results, it could be indicated that surface roughness decreased with the increase of irradiation dose, and the electron and the integrate irradiation has the least and the most effect on the surface roughness and the transmission rate respectively, which indicated that this kind of phenomenon is caused by the surface charging and the internal charging. The result of UV-Vis-VIR and FTIR testing indicated that the transmission rate decreased, especially in ultraviolet band and different particle, caused different effects in different band. There was no obvious effect on surface accuracy through the irradiation.

关键词： Surface roughness

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