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Early Hydration of Composite Cement with Thermal Activated Coal Gangue

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2.content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2.and AFt. The cement with 30% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

On the TOPS mode spaceborne SAR

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Science china(Information Sciences) 2010年第2期53卷 367-378页

作者： BAI Xia 1 , SUN JinPing 2., HONG Wen 3 & MAO ShiYi 2.1 department of electronic engineering, Beijing {2. of Technology, Beijing 100081, china 2.department of electronic engineering, Beihang University , Beijing 100191, china 3 {2. of electronics,Chinese Academy of Sciences, Beijing 100190, china 1. department of electronic engineering Beijing Institute of Technology Beijing 100081 China2. Department of Electronic Engineering Beihang University Beijing 100191 China3. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China

TOPS (terrain observation by progressive scans) is a recently proposed SAR mode for wide swath acquisition, which aims at achieving the same coverage and resolution as the SCAN mode besides creating scalloping-free images. In this paper, a general SAR imaging model used in TOPS and other SAR modes is introduced, where the antenna sweep rate, Doppler centroid rate, illumination time and azimuth resolution are described by a parameter defined as the "mode factor". After analyzing the characteristics of TOPS signal, an algorithm based on chirp-z transform is proposed, in which a new de-rotation function is used. Simulation results validate the proposed algorithm.

关键词： synthetic aperture radar acquisition mode TOPS

Parallel-pipelined Architecture of H.2.4 Deblocking Filter with Adaptive Dynamic Power

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Journal of Shanghai Jiaotong university(Science) 2010年第2期15卷 224-230页

作者：韦虎林涛 department of electronic engineering Shanghai Jiaotong University institute of Very Large Scale Integrated Circuits Tongji University

In H.2.4,the computational complexity and memory access of deblocking filter are variable and depend on the video contents. In this paper,a pipelined VLSI architecture of deblocking filter with adaptive dynamic power is proposed. It avoids redundant computations and memory access by precluding the blocks which can be skipped. And the vertical and horizontal edges are simultaneously processed in an advanced scan order to speed up the decoder. As a result,the dynamic power of the proposed architecture can be reduced (up to about 89%) adaptively for different videos. And the off-chip memory access is improved compared to the previous designs. Moreover,the processing capability of the proposed architecture is very appropriate for real-time deblocking of high-definition television (HDTV,192.× 1080 pixel/frame,30 frame/s video signals) video operation at 38 MHz,which significantly outperforms the previous designs from 1.2. times to 4.8 times.

关键词： deblocking filter adaptive dynamic power parallel processing pipeline H.2.4

Migration Effect of Temperature on Formaldehyde in Porous Building Materials

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湖南大学学报（自然科学版） 2009年第S1期36卷 1-4页

作者： SHEN Xiao-zhong1,2.CHEN Zhen-qian1(1.School of Energy and Environment,Southeast University,Nanjing,Jiangsu 2.0096,china 2.department{2.,Wuxi institute of Commerce,Wuxi,Jiangsu 2.4153,china) School of Energy and Environment Southeast University Nanjing 210096 China department of electronic engineering Wuxi Institute of Commerce Wuxi 214153 China

A coupled heat and formaldehyde migration model based on the non-equilibrium thermodynamic theory and molecule movement theory was *** effect of temperature on the transport coefficients was simulated,and the simulation results were validated with experimental data from the *** calculation shows that air exchange rate larger than 2.h-1 should be prevented,if the purpose is only for formaldehyde emissions *** effects of temperature on formaldehyde migration are obvious.

关键词： formaldehyde migration temperature gradient porous building materials

Study on Simulation of Machining Errors Caused by Cutting Force

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武汉理工大学学报 2006年第S1期28卷 167-172页

作者： SHAO Xiaodong1,ZHANG Liu2.LIN Zhaoxu1 (1. School of Mechano-electronic engineering,Xidian University,Xi’an 710071,{2. 2. 14th institute of china electronics Technology Company,Najin 2.0013,{2.) School of Mechano-electronic engineering Xidian UniversityXi'an 710071China 14th institute of china {2. Technology Company Najin 200013China

Machining errors caused by cutting force are studied in this paper,and an algorithm to simulate errors is putted forward. In the method,continuous machining process is separated into many machining moments. The deformation of work-piece and cutter at every moment is calculated by finite element method. The machined work-piece is gained by Boolean operation between deformed work-piece and cutter. By analyzing data of final work-piece,machining errors are predicted. The method is proved true by experiment.

关键词： machining error simulation cutting force FEM

A new measure to characterize multifractality of sleep electroencephalogram

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Science Bulletin 2006年第24期51卷 3059-3064页

作者： MA Qianli1,2.NING Xinbao1,WANG Jun2.& BIAN Chunhua1 1. State Key Laboratory of Modern Acoustics,department of electronics Science and {2.,institute for Biomedical electronic Engi-neering,Nanjing University,Nanjing 2.0093,china 2. Province Key Laboratory of Image Processing & Image Communica-tion,College of Telecommunications and Information {2.,Nanjing University of Posts & Telecommunications,Nanjing 2.0003,china State Key Laboratory of Modern Acoustics Department of Electronics Science and Engineering Institute for Biomedical Electronic Engineering Nanjing University Nanjing 210093 China Province Key Laboratory of Image Processing & Image Communication College of Telecommunications and Information Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China

Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4.

关键词： sleep electroencephalogram multifractality.

The dynamical properties of Rydberg hydrogen atom near a metal surface

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2. DU Mengli3 & LIN Shenglu1 1. College of Physics and electronics, Shandong Normal University, Jinan 2.0014, china {2. of Mathematics and Physics, Shandong institute of Architecture and engineering, Jinan 2.0014, china 3. institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080, china 1. College of Physics and electronics Shandong Normal University 250014 Jinan China 2. department of Mathematics and Physics Shandong Institute of Architecture and Engineering 250014 Jinan China 3. institute of Theoretical Physics Chinese Academy of Sciences 100080 Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 2.. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.

Fractional Fourier domain equalization for single carrier broadband wireless systems

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Science china(Information Sciences) 2012年第10期55卷 2257-2268页

作者： HUANG KeWu 1,2.TAO Ran 1 & WANG Yue 1 1 department of electronic engineering,Beijing {2. of Technology,Beijing 100081,china 2.{2. of Manned Space System engineering,china Academy of Space Technology,Beijing 100094,china 1. department of electronic engineering Beijing Institute of Technology Beijing 100081 China2. Institute of Manned Space System Engineering China Academy of Space Technology Beijing 100094 China

In this paper,a novel single carrier equalization approach in the fractional Fourier domain(FRFD) is *** can remove all the inter-symbol interference(ISI) and avoid the considerable noise enhancement of the frequency domain-zero forcing(FD-ZF) *** the fractional Fourier transform makes a chirp spread,the impulse response of the deep fading channel may be flattened in some orders of the FRFD while it would be greatly attenuated in the *** searching for an optimal order under certain criterion,we take advantages of the ZF algorithm to mitigate the effects of the ISI *** approach can overcome the contradiction between the ISI mitigation and the noise enhancement of the FD-ZF *** analysis and simulation results show that the proposed FRFD-ZF equalizer can achieve a significant performance and have the same computation cost O(N log N) as the conventional FD linear equalizer,especially in the frequencyselective deep-fading channels.

关键词： fractional Fourier transform single carrier systems zero-forcing equalizer frequency domain linear equalizer

Application of asymptotic waveform approximation technique to hybrid FE/BI method for 3D scattering

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Science in china(Series F) 2007年第1期50卷 124-134页

作者： PENG Zhen1,2.3 & SHENG XinQing2.1 institute of electronics, Chinese Academy of Sciences, Beijing 100080,{2. 2.department of electronic engineering, Beijing institute of Technology, Beijing 100081,{2. 3 Graduated University of Chinese Academy of Sciences, Beijing 100039,{2. 1. institute of electronics Chinese Academy of Sciences Beijing 100080 China 2. department of electronic engineering Beijing Institute of Technology Beijing 100081 China 3. Graduated University of Chinese Academy of Sciences Beijing 100039 China

The asymptotic waveform evaluation （AWE） technique is a rational function approximation method in computational mathemetics, which is used in many appllcations in computational electromagnetlca. In this paper, the performance of the AWE technique in conjunction with hybrid finite element/boundary integral （FE/BI） method is firstly Inveetlgeted. The formuletlon of the AWE applied in hybrid FE/BI method is given in detail. The characteristic implementation of the application of the AWE to the hybrid FE/BI method is discussed. Numarlcel results demonstrate that the AWE technique can greatly speed up the hybrid FE/BI method to acquire wide-band and wide-angle backecatter radar-cross-section （RCS） by complex targets.

关键词： hybrid FE/BI AWE electromagnetic scattering RCS