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Multirange Fractals in Materials: Applications to Fracture and Mechanical Alloying under Ball Milling

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Journal of Materials Science & Technology 1997年第4期13卷 255-259页

作者： Chiwei LUNG(International Centre for Materials Physics, institute of Metal Research,Chinese academy of sciences, shenyang 110015, China) International Centre for Materials Physics Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

A new model of multirange fractals is proposed to explain the experimental results observed on the fractal dimensions of the fractured surfaces in materials. A new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of fractorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals. Mechanical alloying process under ball milling as a non-equilibrium dynamical system has been also analyzed.

关键词： Ball Applications to Fracture and Mechanical Alloying under Ball Milling Multirange Fractals in Materials

Surface Modification of Ceramic Materials Using Excimer Laser

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Journal of Materials Science & Technology 2000年第4期16卷 401-404页

作者： Yingna WU, Zhongchao FENG and Jing LIANG (institute of Metal Research, Chinese academy of sciences, shenyang 110015, China) institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2.3, Al2.3-SiC nanocomposite and Si3N4). Al2.3 and AI2.3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2.a was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2.3, Al2.3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2.3-SiC nanocomposite, 60% (max.); AI2.3, 40% (max.); Si3N4, 12. (max.).

关键词： Surface Modification of Ceramic Materials Using Excimer Laser SiC

LANDSCAPE ECOLOGICAL CONSTRUCTION IN RURAL CHINA:THEORY AND APPLICATION

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Chinese Geographical Science 2001年第2期11卷 104-114页

作者： XIAO Du-ning (Cold and Arid Regions Environmental and Engineering Research institute, the Chinese academy of sciences, Lanzhou 730000, P.R.China institute of applied ecology,the Chinese academy of sciences, shenyang{12.,P.R.China ) Cold and Arid Regions Environmental and Engineering Research institute the Chinese Academy of Sciences Lanzhou P.R. China institute of applied {2. the Chinese Academy of Sciences Shenyang P. R. China

In landscape with overpopulation, intensive management for economic production, and where even small natural-vegetation patches are scarce, ecological conservation generally must be developed in the course of economic development. Thus “landscape ecological construction” has evolved in China. This approach adds spatial elements and alters landscape pattern to strengthen inter-ecosystem linkages, improve functioning of damaged ecosystems, and increase productivity and stability of the whole landscape. Five examples of managed landscapes in China are presented: dike-pond systems in a river delta; multi-pond system in a rice paddy landscape; field-grass-wood grid system on unstable sand dunes; shelterbelt network in a crop field area; and field-grass-wood mosaic system on highly erodible hilly farmland. These indicate that ecological conditions can be improved along with increased economic production. Altering landscape structure and ecological flows by introducing small landscape elements in distinct spatial patterns is considered a key to the results. This reshaping of the land has focused on changing patch size, regularity of arrangement, biological and hydrological corridors, and networks, the matrix and grain size. It suggests that such changes can increase negative feedbacks and increase stability. Finally, planning and design principles are pinpointed for the landscape ecological construction process.

关键词： landscape planning ecological construction rural China

Rapid ecotoxicological assessment of heavy metal combined polluted soil using canonical analysis

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Journal of Environmental sciences 2003年第6期15卷 854-858页

作者： CHEN Su-hua, ZHOU Qi-xing, SUN Tie-heng, LI Pei-jun (institute of applied {2., Chinese academy of sciences, shenyang 110016, China. institute of applied {2. Chinese Academy of Sciences Shenyang 110016 China

Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P2. of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (Pese tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.

关键词： heavy metal combined pollution ecological toxicity canonical analysis

Temperature Fluctuation Synthesis/Simultaneous Densification and Microstructure Control of Titanium Silicon Carbide (Ti_3SiC_2. Ceramics

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Journal of Materials Science & Technology 2000年第5期16卷 461-465页

作者： Zhimei SUN and Yanchun ZHOU (Ceramic and Composite Department, institute of Metal Research, Chinese academy of sciences, shenyang 110015, China) Ceramic and Composite Department Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

A novel temperature fluctuation synthesis/simultaneous densification process was developed for the preparation of Ti3SiC2.bulk ceramics. In this process. Si is used as an in-situ liquid forming phase and it is favorable for both the solid-liquid synthesis and the densification of Ti3SiC2. rainies. The present work demonstrated that the temperature fluctuation synthesis/simultaneous densification process is one of the most effective and simple methods for the preparation of Ti3SiC2.bulk materials providing relatively low synthesis temperature. short reaction time; and simultaneous synthesis and densification. This work also showed the capability to control the microstructure, e.g., the preferred orientation, of the bulk Ti3SiC2.materials simply by applying the hot pressing pressure at different Stages of the temperature fluctuation process. And textured Ti3SiC2.bulk materials with {002. faces of laminated Ti3SiC2.grains normal to the hot pressing axis were prepared.

关键词： Ceramics Temperature Fluctuation Synthesis/Simultaneous Densification and Microstructure Control of Titanium Silicon Carbide Ti3SiC2 SiC

Global convergence property of s-dependent GFR conjugate gradient method

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Chinese Science Bulletin 1998年第23期43卷 1959-1965页

作者： WANG Changyu 1,2.and ZHANG Yuzhong\+1 1. institute of Operations Research in Qufu Normal University, Qufu 2.3165, China 2. institute of applied Mathematics, Chinese academy of sciences, Beijing 100080, China institute of Operations Research Qufu Normal University Qufu China institute of applied Mathematics Chinese Academy of Sciences Beijing China

An \%S\%_dependent GFR method and a generalized conjugate gradient method are designed. Two estimated values of upper bounds for the ratio of β k to β FR k are given. The two convergence theorems are proved. The global convergent properties of \%s\%_dependent GFR method are obtained adopting several choice strategies of steplength and some results in recent literature are extended.

关键词： steplength linear search global convergence conjugate gradient.

Magnetic properties of Jiaxian red clay sequences from northern Chinese Loess Plateau and its paleoclimatic significance

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Science China Earth sciences 2005年第8期48卷 1234-1245页

作者： QIANG Xiaoke, AN Zhisheng, LI Huamei, CHANG Hong & SONG Yougui 1. SKLLQG, institute of Earth Environment, Chinese {2. of sciences, Xi’an 710075, China 2. Guangzhou institute of Geochemistry, Chinese {2. of sciences, Guangzhou 510640, China 1. Chinese academy of {2. SKLLQG Institute of Earth Environment 710075 Xi’an China 2. Chinese academy of {2. Guangzhou Institute of Geochemistry 510640 Guangzhou China

Detailed rock magnetism investigation of the Jiaxian red clay sequences indicated that there are common magnetic mineralogy properties in red clay and loess-paleosol sequences from the Chinese Loess Plateau as well as the marked properties of themselves, magnetic min-erals mainly with magnetite, maghemite, hematite, and possibly limonite/goethite contributing to the magnetic behavior. Meanwhile, it is found that the strong paleosol in red clay sequences has a lower coercivity and higher content of ultra-fine ferrimagnetic grains than that of the weak pa-leosol, which is similar to loess and paleosol in upper Wucheng Loess sequences, and indicates that humid conditions and relatively strong pedogenesis play a significant role in the increase of ultra-fine magnetic minerals and transformation of the magnetic minerals. This suggests that, like Quaternary loess-paleosols, the change of characteristics of paleoclimatic conditions of the late Tertiary red clay deposits is fluctuant. In addition, the results of magnetic hysteresis properties show that the applied saturated field for samples from the Jiaxian red clay sequences is higher than that of the samples from eastern and southern Chinese Loess Plateau. It is obviously shown that there exist more hard magnetic minerals and relatively weak biochemical processes in the Jiaxian red clay sequences on northern Chinese Loess Plateau. We conclude that the paleocli-matic environment is different between northern and eastern/southern Chinese Loess Plateau, and it should be more arid in northern Chinese Loess Plateau.

关键词： northern Chinese Loess Plateau, red clay, magnetic property, paleoclimatic significance.

Synthesis,characterization,properties and crystal structure of heterometallic 1D coordination polymers {[CuLZn·CuLZn(H_2.)]·H_2.}_n

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Science China Chemistry 2006年第4期49卷 338-344页

作者： TAO Ruojie1, LI Fu’an1, ZANG Shuangquan1, CHENG Yanxiang2.& NIU Jingyang1 1. Chemistry and Chemical Engineering College of Henan University, Kaifeng 475001, China 2. Changchun institute of applied Chemistry, Chin{2. academy of sciences, Changchun 13002., China 1. Chemistry and Chemical Engineering College of Henan University Kaifeng 475001 China 2. Changchun institute of applied Chemistry Chinese Academy of Sciences Changchun 130022 China

Copper-zinc heterometallic 1D chain coordination polymer has been synthesized and characterized by elemental analysis, and IR spectra etc. The crystal structure was determined by single-crystal X-ray diffraction analyses. The title complex is 1D chain coordination polymer with the chemical formula {[CuLZn·CuLZn(H2.)]·H2.}n, where H4L=N-(2.hydroxybenzamido)-N’-(3-carboxy- lsalicylidene)ethylenediamine. Its structural unit is comprosed of two tetranuclear cycles formed by two dissymmetrical tetranuclear units. These units polymerized each other to form 1D chain coordi- nation polymer.

关键词： copper, zinc, heterometallic coordination polymer, crystal structure.

Two-dimensional Riemann problems of simplified Euler equation

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Chinese Science Bulletin 1998年第6期43卷 441-444页

作者： YANG Xiaozhou 1,2.and HUANG Feimin+1 1. institute of applied Mathematics, Chin{2. academy of sciences, Beijing 100080, China 2. Department of Mathematics, Shantou University, Guangdong 515063, China institute of applied Mathematics Chinese Academy of Sciences Beijing China Department of Mathematics Shantou University Guangdong China

The two-dimensional Riemann problem of simplifed Euler equation is discussed, in which initial value contains two different constant states that are separated by a smooth curve. This problem is a natural description of realistic phenomena, but it is hard to study by conventional idea. So a new approach is proposed. Some new properties about two-dimensional rarefaction wave, shock wave and intermediate state of solutions are disclosed.

关键词： D Riemann problem implicit functions cylindrical surface pencil of cylindrical surface.