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Evidence from isotopic geochemistry as an indicator of eutrophication of Meiliang Bay in Lake Taihu, China

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science China Earth sciences 2006年第z1期49卷 62-71页

作者： LIN Lin, WU Jinglu & WANG Sumin Nanjing Institute of Geography & Limnology, chinese academy of sciences, Nanjing 210008, China Graduate University of the chinese academy of sciences, Beijing 100039, China chinese acad sci Nanjing Inst Geog & Limnol Nanjing 210008 Peoples R China chinese acad sci Grad Univ Beijing 100039 Peoples R China

In this paper, Lake Taihu, a large shallow freshwater lake in China, is chosen as an example of reconstruction of eutrophication through the comparison between stable isotopes from dissolved nutrients and plants and water column nutrient parameters and integration of multiple proxies in a sediment core from Meiliang Bay including TN, TP, TOC, C/N, δ15N, δ13C, etc. Differences in aquatic plant species and trophic status between East Taihu Bay and Meiliang Bay are indicated by their variations in δ13C and δ15N of aquatic plants and δ15N of NH4+. A significant influence ofexternal nutrient inputs on Meiliang Bay is reflected in temporal changes in δ 15N of NH4+ and hydro-environmental parameters. The synchronous change between δ13C and δ15N values of sedimented organic matter (OM) has been attributed to elevated primary production at the beginning of eutrophication between 1950 and 1990, then recent inverse correlation between them has been caused by the uptake of 15N-enriched inorganic nitrogen by phytoplankton grown under eutrophication and subsequent OM decomposition and denitrification in surface sediments, indicating that the lake has suffered from progressive eutrophication since 1990. Based on the use of a combination of stable isotopes and elemental geochemistry, the eutrophication of Meiliang Bay in Lake Taihu could be better traced. These transitions of the lake eutrophication respectively occurring in the 1950s and 1990s have been suggested as a reflection of growing impacts of human activities, which is coincident with the instrumental data.

关键词： stable carbon isotope of OM, stable nitrogen isotope, eutrophication, Lake Taihu.

Microstructure and Tribological Properties of TiB_2/TiB/TiN_x(x=1,0.3)/Ti Composite Coating Produced on Pure Ti by Laser Surface Alloying

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稀有金属材料与工程 2012年第S1期41卷 344-349页

作者： Guo Chun1,2,Chen Jianmin1,Zhou Jiansong1,Zhao Jierong1,2,Wang Lingqian1,2,Yu Youjun1,2,Zhou Huidi 1 1 Lanzhou Institute of Chemical Physics,chinese academy of sciences,Lanzhou 730000,China 2 Graduate University of chinese academy of sciences,Beijing 100039,China chinese acad sci Lanzhou Inst Chem Phys Lanzhou 730000 Peoples R China chinese acad sci Grad Univ Beijing 100039 Peoples R China

TiB2/TiB/TiNx(x=1,0.3)/Ti composite coating was prepared on pure Ti by laser surface alloying by using powders of boron as starting *** composite coating was examined by X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM)and scanning electron microscopy(SEM).The friction and wear properties of the composite coating were examined using a pin-on-disk tester under dry sliding wear *** results showed that the top surface of the composite coating was mainly composed of TiB2,TiB,TiN0.3,TiN and Ti phases,while the interface of the composite coating was composed of TiB and Ti *** composite coating showed sticklike structure near the top surface,and dendrites structure near the *** friction and wear test showed that the composite coating had better wear resistance than pure Ti due to their higher microhardness than that of pure Ti substrate.

关键词： pure Ti laser surface alloying TiB2 composite coating friction and wear property

SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID)WITH POLY(ETHYLENE GLYCOL)THROUGH ANIONIC POLYMERISATION

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chinese Journal of Polymer science 2000年第1期18卷 19-23页

作者： Xin-tao Shuai Zbigniew Jedlinski Qiang Luo Nozirow Farhod Institute of Chemistry, chinese academy of sciences, Beijing 100080, China Institute of Polymer Chemistry, Polish academy of sciences, 41-800 Zabrze, Poland Institute of Synthetic Fibre, chinese academy of Textile sciences, Beijing 100025, China chinese acad sci Inst Chem Beijing 100080 Peoples R China Polish acad sci Inst Polymer Chem PL-41800 Zabrze Poland chinese acad Text sci Inst Synthet Fibre Beijing 100025 Peoples R China

A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of beta-butyrolactone (beta-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which were prepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M-n = 2000, 4000 and 6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterized by IR, H-1-NMR and GPC.

关键词： block copolymer poly(ethylene glycol) poly(3-hydroxybutyric acid)

Study on Adsorption of Water in MCM41 Containing Metal Ions by Molecular Dynamic Simulations

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Journal of Thermal science 2004年第2期13卷 187-192,132页

作者： Shiqiang Liang Jingzhong Xu Jian Chen chinese acad sci Inst Engn Thermophys Beijing 100080 Peoples R China

To clarify whether the adsorption of water in MCM41 can be promoted by introducing some metal ions onto its surface, molecular dynamics simulations were carried out to investigate the behavior of some water molecules confined in mesoporous MCM41 whose pore size was tailored to 2.5 nm. Pure silica MCM41 as well as those containing some metal ions such as Al3+, Cu2+, and La3+ was simulated, and by observing the local average density distribution of particles, we found that both the MCM41 containing Al3+ and that of La3+ performed higher adsorption and lower desorption temperature. It is concluded that the adsorption is improved mainly owing to the diversities of polarity, active sites, and structure imported by these metal ions.

关键词： MCM41 molecular dynamics adsorption.

PHASE TRANSFORMATION OF Al-Ti COATINGS ON Co-BASE SUPERALLOY DZ40M DURING HIGH TEMPERATURE OXIDATION

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中国有色金属学会会刊：英文版 1998年第4期8卷 51-56页

作者： Liu, PS Sun, XF Jin, T Guan, HR Hu, ZQ chinese acad sci Inst Met Res Shenyang 110015 Peoples R China

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ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅｉｓａｓｅｒｉｏｕｓｐｒｏｂｌｅｍｏｆｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｏｘｉｄａｔｉｏｎｏｎｔｕｒｂｉｎｅｃｏｍｐｏｎｅｎｔｓ，ｈｅｎｃｅ，ｖａｒｉｏｕｓｃｏａｔｉｎｇｓｗｉｔｈａｌｕｍｉｎｉｄｅａｒｅｍａｎｕｆａｃ...

关键词： Co base superalloy coating phase transformation

OPTICALLY ACTIVE COPOLYESTERS BASED ON AXIALLY DISSYMMETRIC 1,1’-BINAPHTHALENE-2,2’-DIYL UNITS

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chinese Journal of Polymer science 2000年第5期18卷 443-447页

作者： Chuan-fu Chen Min Ai Zhong Li Hong-wei Liu Ai-jun Gong Fu Xi Institute of Chemistry, chinese academy of sciences, Beijing 100080, China chinese acad sci Inst Chem Beijing 100080 Peoples R China

Optically active copolyesters based on axially dissymmetric 1,1'-binaphthalene-2,2'-diyl units have been preparedand characterized by specific rotation, ^(13)C-NMR and CD spectra. The results show that the rotation signs of tribasiccopolyesters or the mixture of corresponding homopolyesters obey a three dimensional quadrant pattern. The composition ofthe copolyesters was determined from ^(13)C-NMR spectra to be triad sequence distributions and corresponding with the ratioby feed.

关键词： Optical activity Copolyester 1, 1'-Binaphthalene-2,2'-diol Diethyl tartrate

Spatio-temporal characteristics of aerosol distribution over Tibetan Plateau and numerical simulation of radiative forcing and climate response

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science China Earth sciences 2001年第S1期44卷 375-384页

作者：李维亮于胜民 chinese acad Meteorol sci Beijing 100081 Peoples R China

In this paper we have analyzed aerosol distribution over the Tibetan Plateau by using the global monthly mean satellite data of Stratospheric Aerosol and Gas Experiment II (SAGEⅡ).The results are as follows: (1) Stratospheric aerosol optical depth can oscillate in the four seasons. It means that the aerosol optical depth is the thickest in winter and a little thinner in spring and the thinnest in summer and then a little thicker in autumn. We have found that the oscillation is caused by the oscillation of tropopause in different seasons. (2) Stratospheric aerosol comes mainly from sprays of volcano. After eruption of Mount Pinatubo aerosol optical depth in stratosphere over the Tibetan Plateau increases 10 times compared with before. (3) The characteristic of aerosol vertical distribution over the Tibetan Plateau is that there is an extremely high value at the altitude of 70 hPa. The most interesting thing is that the extremely high value can oscillate between 50 hPa and 100 hPa. We have verified that the oscillation is a unique characteristic over the Tibetan Plateau by comparing it with South China and North China. Then the radiative forcing and regional climate response over the Tibetan Plateau of aerosol are investigated. We have discovered such things as followed by: (1) The radiative forcing is positive because the parameterized aerosol optical depth is less than 0.14 which is the optical depth of the uniform background boundary aerosol layer. It is 0-3 W/m2 in January and 0-4 W/m2 in April and less than 3 W/m2 in July and 3-6 W/m2 in October. (2) Ground temperature rises 0.1-0.2 K in October which is the biggest increasing magnitude, and 0.01-0.02 K in July which is the smallest one. It rises about 0.05-0.01 K in January and April. (3) Air temperature near the earth's surface and the one at the altitude of 500 hPa rise too, but the increasing magnitude is less than the former one.

关键词： aerosol Tibetan Plateau optical depth radiative forcing.

Applications of Electrical Capacitance Tomography in Two Phase Flow Visualization

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Journal of Thermal science 2004年第2期13卷 179-186页

作者： Shi Liu Runsheng Yan Haigang Wang Fan Jiang Xiangyun Dong chinese acad sci Inst Engn Thermophys Beijing 100080 Peoples R China

The successful application of Electrical Capacitance Tomography (ECT) depends heavily on the image reconstruction speed and quality. The two requirements usually cannot be satisfied simultaneously. Also, for a large number of acquired 2D ECT images, a 3D presentation of them is much desired to track the variations of the material distribution in a third dimension. To facilitate ECT for practical flow analyses in process engineering, the authors have recently developed algorithms for 3D image presentation and for online iterative image reconstruction that only takes the same time as a linear back projection method but yields good image qualities as the Landweber iterative method does. The new methods have been successfully applied to visualize several classes of two phase flows, namely fluidization, cyclone separation, circulating rate determination in circulating fluidized beds, pneumatic conveying, rotating drum mixing. Special characteristics in each case have been discussed and valuable results are obtained, which are reported in this paper.

关键词： ECT two phase flow visualization.

Experimental Study on the Dynamic Characteristics of a Gas Turbine Combustor Burning Syn-gas

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Journal of Thermal science 2004年第4期13卷 376-381页

作者： Yu Lei Gang Xu Aibing Fang Chaoqun Nie Weiguang Huang chinese acad sci Inst Engn Thermophys Beijing 100080 Peoples R China

The present study focused on the development of a full-scale gas turbine combustor burning syn-gas from the coal-based multi-production. The dynamic features of a variety of parameters of the combustor, such as temperature and pressure during the procedures of startup and thermal load shifting, were measured and analyzed. The frequency and power spectrum of pressure fluctuation were analyzed by applying FFT and 1D continuous MORLET wavelet methods. The results show that the pressure fluctuation has distinct patterns during startup and load-transition procedures. The relationship between these dynamic features and the stability, safety and efficiency of gas turbine combustors burning syn-gas are preliminarily discussed.

关键词： gas turbine combustor dynamic characteristics frequency and power spectrum analyses.