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Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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science china(Information sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3 1Department of Electronic and Information Engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, china 2Department of Information Engineering, Jiangsu City Vocation college, nanjing 210036, china 3college of Communication and Information Engineering, nanjing university of Posts and Telecommunications, nanjing 210003, china Department of Electronic and Information Engineering Zhejiang Institute of Media and Communications Hangzhou China Department of Information Engineering Jiangsu City Vocation College Nanjing China college of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

On the interannual variation in spring atmospheric inter-hemispheric oscillation linked to synchronous climate in china

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Progress in Natural science:Materials International 2009年第9期19卷 1125-1131页

作者： Chuhan Lu, Zhaoyong Guan * Key Laboratory of Meteorological Disaster of Ministry of Education and college of Atmospheric sciences, nanjing university of Information science and Technology, nanjing 210044, china Key Laboratory of Meteorological Disaster of Ministry of Education and college of Atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China

Based on NCEP/NCAR monthly mean reanalysis data and surface observations of Chinese stations, inter-hemispheric oscillations (IHO) of spring atmospheric mass on an interannual basis in conjunction with the linkage to the synchronous climate over china are studied. Results suggest that the spring IHO exhibits a significant seesaw pattern for air mass at bi-hemispheric mid-high latitudes, with a consistent vertical circulation structure. The EOF decomposition of zonally mean surface pressures without signals of Arctic Oscillation (AO) and Antarctic Oscillation (AAO) indicates that the EOF1 IHO feature is remarkable, with the corresponding time coeficients correlated with the spring IHO index (IIHO) at 0.93; the spring IHO bears a close relation to the synchronous climate in china, showing the surface pressure, temperature and relative humidity over the country to be in good correlation with IIHO; the spring duststorms in Qinghai, Gansu, Shaanxi and Inner Mongolia have bearing on IHO. Positive-phase IIHO promotes the strengthening of the Siberian high, during which zonal winds between 60°E and 150°W show a longitudinal teleconnection structure extending from the Arctic to Antarctica, leading to positive westerly wind anomalies over Asia, affecting the spring climate of china.

关键词： Air mass Inter-hemispheric oscillation (IHO) Spring climate china

Analysis of crack propagation in concrete structures with structural information entropy

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science china(Technological sciences) 2010年第7期53卷 1943-1948页

作者： BAO TengFei1’2, PENG Yan1’2, CONG PeiJiang1’2 & WANG Jialin1’2 1 State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering, Hohai university, nanjing 210024, china 2 National Engineering Research Center ofWater resources Efficient Utilization and Engineering Safety, Hohai university, nanjing 210024, china State Key Laboratory of Hydrology-Water resources and Hydraulic Engineering Hohai University Nanjing China National Engineering Research Center of Water resources Efficient Utilization and Engineering Safety Hohai University Nanjing China

The propagation of cracks in concrete structures causes energy dissipation and release, and also causes energy redistribution in the structures. Entropy can characterize the energy redistribution. To investigate the relation between the propagation of cracks and the entropy in concrete structures, cracked concrete structures are treated as dissipative structures. Structural information entropy is defined for concrete structures. A compact tension test is conducted. Meanwhile, numerical simulations are also carried out. Both the test and numerical simulation results show that the structural information entropy in the structures can characterize the propagation of cracks in concrete structures.

关键词： crack entropy concrete sun

Aoyitake plagiogranite in western Tarim Block, NW china: Age, geochemistry, petrogenesis and its tectonic implications

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science china Earth sciences 2006年第11期49卷 1121-1134页

作者： ZHANG Chuanlin1,2, YU Haifeng3, YE Haimin2, ZHAO Yu2 & ZHANG Dongsheng4 1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of sciences, Guangzhou 510640, china 2. nanjing Institute of Geology and Mineral resources, nanjing 210016, china 3. Tianjin Institute of Geology and Mineral resources, Tianjin 300170, china 4. The 2nd Regional Geological Investigation Party, Xinjiang Bureau of Geology and Mineral resources, Changji 831100, china Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China nanjing Institute of Geology and Mineral resources Nanjing China Tianjin Institute of Geology and Mineral resources Tianjin China The 2nd Regional Geological Investigation Party Xinjiang Bureau of Geology and Mineral Resources Changji China

SHRIMPP U-Pb zircon age and geochemical and Nd isotopic data are reported for the Aoyitake plagiogranite in western Tarim Block, NW china. The plagiogranite intruded the Middle Pro- terozoic and Lower Carboniferous with an exposure area of ca. 60 km2 and crystallized at 330.7±4.8 Ma. Rock types mainly include tonalite, trondhjemite and minor amounts of diorite and quartz-diorite. Feldspars in the rocks are dominated by oligoclase-andesine, and minor perthite observed locally. The granites are sodic with Na/K ratios (molar) between 4 and 87. Total REE (50-220 ppm) show a clear positive correlation with SiO2. There is no LRRE/HREE fractionation (LaN/YbN=0.5-1.5), me- dium negative Eu anomalies (δ Eu=0.3-0.6), high Y content and low Sr/Y ratio (~1.0). These granites exhibit relatively juvenile Nd T2DM model ages of 470 to 580 Ma and positive εNd(331 Ma) values of 6.23 to 7.65. The aforementioned characteristics are similar to those of ocean island or ocean ridge plagiogranites. However, the regional geology, especially its scale, precludes that the plagiogranite pluton was derived directly from fractionational crystallization of mantle-derived basaltic magma. We interpreted that the primary magma of the pluton might be tonalitic in composition generated by ca. 50% partial melting of the juvenile basaltic crust. The primary magma experienced intensive frac- tionational crystallization, and intruded into the middle to upper crusts to form the granite pluton. In combination with the previous regional geological data, it is concluded that the plagiogranite pluton was emplaced within the Tarim Block in respond to the Carboniferous continental rifting along the Tianshan orogenic belt.

关键词： western Tarim, Aoyitake plagiogranite, age, geochemistry, tectonic implications.

Effect of Zn^(2+) Content on the Microstructure and Magnetic Properties of Nanocrystalline Ni_(1-x)Zn_xFe_2O_4 Ferrite by a Spraying-coprecipitation Method

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Journal of Wuhan university of Technology(Materials science) 2010年第3期25卷 429-431页

作者：刘银 college of Materials science and Engineering Anhui University of Science and Technology

Nanocrystalline Ni1-xZnxFe2O4 ferrites with 0≤x≤1 were successfully prepared by a spraying-coprecipitation *** microstructure was investigated by using XRD and *** properties were measured with vibrating sample magnetometer（VSM） at room *** results show that the grain size of nanocrystalline Ni1-xZnxFe2O4 ferrite calcined at 600 ℃ for 1.5 h is about 30 *** parameter and specific saturation magnetization Ms of nanocrystalline Ni1-xZnxFe2O4 ferrite increase with the Zn^2＋ ions content at room temperature,and maximum Ms is 66.8 A·m^2·kg^-1 as the Zn^2＋ ions content is around 0.5,and coercivity Hc of the nanocrystalline Ni1-xZnxFe2O4 ferrite decreases with Zn^2＋ ions content.

关键词： nanocrystalline material Ni-Zn ferrite spraying-coprecipitation method magnetic properties microstructure

Tillage Effect on Organic Carbon in a Purple Paddy Soil

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Pedosphere 2006年第5期16卷 660-667页

作者： HUANG Xue-Xia GAO Ming WEI Chao-Fu XIE De-Ti PAN Gen-Xing college of resources and Environment Southwest Agricultural University Chongqing 400716 （China） college of Environmental science and Technology Guangzhou University Guangzhou 510006 （China） college of resources and Environment Nanjing Agricultural University Nanjing 210095 （China）

The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, china. Organic carbon storage in the 0-20 and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr) > conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.

关键词： carbon sequestration organic carbon storage purple paddy soil tillage system

Molecular dynamics simulation of mechanical properties of TATB/fluorine-polymer PBXs along different surfaces

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science china Chemistry 2005年第6期48卷 504-510页

作者： XIAO Jijun1, HUANG Yucheng1, HU Yingjie1,2 & XIAO Heming1 1. Department of Chemistry, nanjing university of science and Technology, nanjing 210094, china 2. Department of Chemistry, nanjing Xiaozhuang college, nanjing 210017, china Correspondence should be addressed to Xiao Heming (email: xiao@***) Department of Chemistry Nanjing University of Science and Technology Nanjing China Department of Chemistry Nanjing Xiaozhuang College Nanjing China

The mechanical properties of PBXs composed of the well-known insensitive explo-sive TATB (1,3,5-Triamino-2,4,6-trinitrobenzene) crystal and four kinds of typical fluo-rine-polymers, i.e. poly (vinylidene difluoride) (PVDF), polychlorotrifluoroethylene (PCTFE), fluo-rine rubber (F2311) and fluorine resin (F2314) individually, have been simulated by molecular dy-namics (MD) method. The results show that the mechanical properties of TATB can be effectively improved by blending with a small amount of fluorine-polymers. Different mechanical properties of PBXs are obtained by putting fluorine-polymer binders parallel to different crystalline surfaces. The whole effect of improving mechanical properties is found to be (010)?(100)>(001).

关键词： TATB, polymer bonded explosives, mechanical properties, molecular dynamics.

Distributed optimization using virtual and real game strategies for multi-criterion aerodynamic design

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science china(Technological sciences) 2008年第11期51卷 1939-1956页

作者： TANG ZhiLi1, BAI Wen2 & DONG Jun3 1 college of Aerospace Engineering, nanjing university of Aeronautics & Astronautics, nanjing 210016, china 2 Chinese Aeronautics Computation Technique Research Institute, Xi’an 710068, china 3 Chinese Aerodynamic Research Institute on Aeronautics, Shenyang 110034, china college of Aerospace Engineering Nanjing University of Aeronautics & Astronautics Nanjing China Chinese Aeronautics Computation Technique Research Institute Xi’an China Chinese Aerodynamic Research Institute on Aeronautics Shenyang China

This paper introduces the virtual and real game concepts to investigate multi-criterion optimization for optimum shape design in aerodynamics. The constrained adjoint meth- odology is used as the basic optimizer. Furthermore, the above is combined with the vir- tual and real game strategies to treat single-point/multi-point airfoil optimization. In a symmetric Nash Game, each optimizer attempts to optimize one’s own target with ex- change of symmetric information with others. A Nash equilibrium is just the compromised solution among the multiple criteria. Several kinds of airfoil splitting and design cases are shown for the utility of virtual and real game strategies in aerodynamic design. Successful design results confirm the validity and efficiency of the present design method.

关键词： multi-criterion optimization Nash equilibrium virtual game real game aerodynamics distributed computing

Soil Fertility Indices of Citrus Orchard Land along Topographic Gradients in the Three Gorges Area of china

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Pedosphere 2011年第6期21卷 782-792页

作者： WU Dian-Ming YU Yuan-Chun XIA Li-Zhong YIN Shi-Xue YANG Lin-Zhang college of Forest resources and Environment Nanjing Forestry University Nanjing 210037 （China） State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） college of Environmental science and Engineering Yangzhou University Yangzhou 22500g （China）

In the Three Gorges Area of china, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat (Triticum aestivum) and peanut (Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (> 0.25 mm) contents at the 0–5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (> 0.25 mm) contents at both the 0–5 and 5–20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (> 0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.

关键词： intercropping slope land soil nutrients soil water-stable aggregates straw mulching