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Phase transition in the Zr_(60)Al_(15)Ni_(2.) bulk metallic glass subjected to rolling at room temperature

science China(Technological sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2. LI Jinfu1, ZHOU Yaohe1 & WU Yanqing3.1. State Key Laboratory of Metal Matrix Composites, School of Materials science and {2., Shanghai Jiao Tong {2., Shanghai 2.003., China 2. School of Materials science and {2., Taiyuan {2. of science and Technology, Taiyuan 03.02., China 3. School of environmental science and {2., Shanghai Jiao Tong {2., Shanghai 2.003., China State Key Laboratory of Metal Matrix Composites School of Materials Science engineering Shanghai Jiao Tong University Shanghai 200030 China School of Materials science engineering Taiyuan University of Science Technology Taiyuan 030024 China School of environmental science engineering Shanghai Jiao Tong University Shanghai 200030 China

The microstructure evolution of the Zr60Al15Ni2. metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 2.%, the values of FWHM; ΔH are lower than that of the as-cast state. When reaches 3.%, the values of FWHM; ΔH become larger than that of the as-cast state, while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

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ATP as anindicator of biomass activity in thermophilic upflow anaerobic sludge blanket reactor

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Journal of environmental sciences 2000年第3期12卷 380-384页

作者： CHEN Hong (department of environmental {2. and {3. ,Zhejiang university ,Hangzhou 3. 0 0 2.7,China) 浙江大学浙江杭州 3 1 0 0 2

Thisworkinvestigatedthebiomassactivityinathermophilicupflowanaerobicsludgeblanket (UASB )reactorof wastewatertreatment .SynthetictextilewastewaterwithpH 1 0— 1 1 ,CODlevelof2.0 0 0— 3. 0 0mg/Lwastested .Cellularadenosine triphosphate (ATP)involatilesolids (VS ;mgATP/gVS)wasmeasuredandexpressedasspecificATPcontenttocomparethe biomassactivityinupzoneandlowerzoneinUASBreactor .TheresultshowsthatthespecificATPcontentbasedontotalvolatile solids (VS)inlowerzone ( 0 .0 4 6mgATP/gVSaverage)ismuchlowerthanthatinupzone ( 0 .62.gATP/gVSaverage)duetohighcontentofinactivebiomassandhighpHinlowerzone .TheSATPinupzoneincreasesasHRTincreasesandapproachestoa maximumvalueof 0 .85mgATP/gVSatHRTof 7h ,thendecreases .ItshowsmostofthetotalVSinupzonerepresentactive bacterialbiomassatHRTof 7h .Rateofsubtractutiliz*** effectofHRTonSATPinlowerzoneisnotassignificantasonSATPinupzone .ThebuffercapacityofthethermophilicUASB reactorisverygood .ItistheactivityofsludgegranulesinlowerzonethatgivetheUASBreactorsuchagoodbuffercapacitytotheinlethighpH .

关键词： ATP biomassactivity UASBreactor

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A land surface model incorporated with soil freeze/thaw and its application in GAME/Tibet

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science China Earth sciences 2006年第12期49卷 1311-1322页

作者： HU Heping1, YE Baisheng2. ZHOU Yuhua3.& TIAN Fuqiang1 1. department of Hydraulic {2., Tsinghua {2., Beijing 100084, China 2. Cold and Arid Regions {3. and {2. Research Institute, Chinese Academy of sciences, Lanzhou 73.000, China 3. department of Civil {2., Massachusetts Institute of Technology, USA 1. department of Hydraulic engineering Tsinghua University Beijing 100084 China 2. Cold and Arid Regions environmental and engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China 3. department of Civil {2. Massachusetts Institute of Technology USA

Land surface process is of great importance in global climate change, moisture and heat exchange in the interface of the earth and atmosphere, human impacts on the environment and eco- system, etc. Soil freeze/thaw plays an important role in cold land surface processes. In this work the diurnal freeze/thaw effects on energy partition in the context of GAME/Tibet are studied. A sophisti- cated land surface model is developed, the particular aspect of which is its physical consideration of soil freeze/thaw and vapor flux. The simultaneous water and heat transfer soil sub-model not only reflects the water flow from unfrozen zone to frozen fringe in freezing/thawing soil, but also demon- strates the change of moisture and temperature field induced by vapor flux from high temperature zone to low temperature zone, which makes the model applicable for various circumstances. The modified Picard numerical method is employed to help with the water balance and convergence of the numerical scheme. Finally, the model is applied to analyze the diurnal energy and water cycle char- acteristics over the Tibetan Plateau using the Game/Tibet datasets observed in May and July of 1998. Heat and energy transfer simulation shows that: (i) There exists a negative feedback mechanism between soil freeze/thaw and soil temperature/ground heat flux; (ii) during freezing period all three heat fluxes do not vary apparently, in spite of the fact that the negative soil temperature is higher than that not considering soil freeze; (iii) during thawing period, ground heat flux increases, and sensible heat flux decreases, but latent heat flux does not change much; and (iv) during freezing period, soil temperature decreases, though ground heat flux increases.

关键词： land surface model,soil freeze/thaw,GAME/Tibet,simultaneous liquid,vapor and heat transfer.

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Comparison study of trapped water in human erythrocytes by EPC and DSC method and its application

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science China(Technological sciences) 2004年第3期47卷 343-351页

作者： ZHAO Gang1, HE Liqun1, GUO Xiaojie2. LIU Zhong3. LUO Dawei1,3.& GAO Dayong1,3.1. Cryobiomedical engineering Research Institute, department of Thermal {2. and Energy engineering, university of {2. and Technology of China, Hefei 2.0}02., China 2. Red Cross Blood Center of Hefei, Hefei 2.0}02., China 3. department of Mechanical engineering, university of Kentucky, Lexington, KY 40506-0108, USA Univ Sci & Technol China Cryobiomed Engn Res Inst Dept Thermal Sci & Energy Engn Hefei 230027 Peoples R China Red Cross Blood Ctr Hefei Hefei 230022 Peoples R China Univ Kentucky Dept Mech Engn Lexington KY 40506 USA

The novel differential scanning calorimetry method for determining trapped water volume of human red blood cell during freezing process has been reexamined. Results show that the final erythrocyte volume is 53. of its isotonic volume after freezing to -40℃. An electronic particle counter (MultisizerTM III, Beckman Coulter Inc., USA) was used to measure cell volume changes in response to hypertonic solution. Using this approach, when extracellular solution was 3.86 mOsm, the equilibrium cell volume was found to be 57% of its isotonic value. Both results indicate that 3.%—40% of intracellular water is trapped and cannot respond to osmotic difference between intra- and extracellular solution. These findings are consistent with the published data: at least 2.%—3.% of the isotonic cell water volume is retained within RBCs during freezing. Some applications of the values of trapped water are addressed.

关键词： differential scanning calorimeter/DSC, electronic particle counter/EPC, cell volumetric change, red blood cell/RBC/erythrocyte

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Study on Theory and Application of the Energy Method used for Analyzing Compressive Instability in Sheet Forming

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厦门大学学报（自然科学版） 2002年第S1期41卷 126-127页

作者： XIONG Zhi-qing 1, XIE Lan-sheng 2.(1. department of Mechanical engineering, {2. Institute of Techno logy, {2. 2.0013. China 2. College of Mechanical and Electrical engineering, nanjing university of Aer onautics and Astronautics, {2. 2.0016, China)

It is pointed out that there was serious weakness w he n using the energy method for studying compressive plastic instability in sheet forming in the past. Where applying the deduced instability strengths to relativ e engineering analysis, theoretical solutions were away from practices. Its basi c reason is that simplified process in mathematical analysis of elastic bending energy was completely applied to that of plastic bending energy. Where the cambe r expressed by function of displacement normal to a plate was approximated to re alistic deflective camber, the displacement of deflected plate to compressed dir ection was neglected. With the aid of the improved instability strengths, the pr edictions on both critical buckling dimension of blank in cup deep-drawing with out blankholder through cylindrical die or conical die and the minimum blankhold er pressure to prevent buckling under constant load are universally in agreement with both experimental results and experiential data. On the bases of above-mentioned improvement, the approximate expressions for bo th the curvature and the twist used in equation of the energy of elastic bending are also ameliorated. Thus the obtained general equations for both the energy a nd the work done by internal force in plastic bending of a plate are more precis e than before. In the analyses of plastic buckling of shell with bending moment, the effect of bending moment is considered through the work done by simulative bending for ce. The method proposed in this paper can not only simplify analyses but also ge t practical result.

关键词： sheet forming deep-drawing buckling energy me thod

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Geochemistry of Trace and Rare Earth Elements in Red Soils from the Dongting Lake Area and Its environmental Significance

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Pedosphere 2009年第5期19卷 615-622页

作者： MAO Long-Jiang MO Duo-Wen YANG Jing-Hong SHI Chen-Xi College of Atmospheric science Nanjing University of Information Science & Technology Nanjing 210044 (China) College of Urban and environmental sciences Peking University Beijing 100871 (China) department of Earth sciences Nanjing University Nanjing 210093 (China)

Trace element(TE) and rare earth element(REE) contents in red soils from the Dongting Lake area of China were determined to understanding the provenance and weathering characteristics of the red *** results showed similar REE distribution patterns among red soils from the Dongting Lake area,Xiashu loess from Zhenjiang,loess and Pliocene red soil from the Loess *** patterns implied a similar provenance from dust-storms,except for red soil R5 which formed by bedrock weathering and had significant light REE(LREE) enrichment and heavy REE(HREE) depletion due to longer weathering periods and higher intensity of *** element,especially the Rb/Sr and Li/Ba ratios,and REE,especially the LREE/HREE ratio and δEu could trace weathering *** Rb/Sr,Li/Ba,and LREE/HREE ratios and negative Eu anomalies were present in the red soils from the Dongting Lake *** weathering intensity was in the decreasing order of R5 in the Dongting Lake area > red soils from the Dongting Lake area(including reticulate red soil,weak reticulate red soil,and homogeneous red soil formed by dust storms) > Xiashu loess from Zhenjiang > loess-paleosol and Pliocene red soil from the Loess *** in the TE and REE contents of soil could be effectively used to study the provenance and the weathering intensity.

关键词： Hunan Province provenance sedimentary processes weathering intensity

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Reduction of VOC emissions by a membrane-based gas absorption process

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Journal of environmental sciences 2009年第8期21卷 1096-1102页

作者： LI Rui, XU Jun, WANG Lianjun, LI Jiansheng, SUN Xiuyun School of Chemical engineering, nanjing university of {2. and Technology, {3. 2.0094, China. [a]School of Chemical engineering Nanjing University of Science and Technology Nanjing 210094 China. E-mail: drbeaneyes@***

A membrane-based gas absorption （MGA） process was evaluated for the removal of volatile organic compounds （VOCs） based on C6H6/N2.mixture. The absorption of C6H6 from a C6H6/N2.mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine （NFM） as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.

关键词： VOCs removal membrane contactor membrane-based gas absorption mass transfer model

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Numerical Study of Heat Transfer Enhancement by Liquid Film on the Walls

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Journal of Thermal science 1994年第2期3卷 110-116页

作者： Chunlin Xia(department of Power engineering,{2. of Aeronautics and Astronautics, {3. 2.0016,China) 1. department of Power engineering Nanjing University of Aeronautics and Astronautics 210016 Nanjing China

The mechanism of heat transfer enhancement by liquid film on the channel walls has been investigated in laminar mixed convective flows. The temperature distribution, velocity and mass fraction distributions, and the effects of the wetted wall temperatures and the Reynolds number on the momentum,heat and mass transfer were examined in details. Results show that the liquid film can enhance heat transfer along the wetted walls by 5-10 times.

关键词： liquid film vaporization heat and mass transfer enhancement.

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Analysis on cohesive crack opening displacement considering the strain softening effect

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science China(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3.1. Mechanics department, Shandong {2. of Technology, Zibo 2.5049, China 2. Civil {2. department, Dalian {2. of Technology, Dalian 11602., China 3. Mathematics department, Ocean {2. of China, Qingdao 2.6071, China Mechanics department Shandong University of Technology Zibo 255049 China Civil engineering department Dalian University of Technology Dalian 116024 China Mathematics department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

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Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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science China(Technological sciences) 2010年第6期53卷 1711-1716页

作者： ZHANG ZhiJun1,2.3.GU ChongShi1,2.BAO TengFei1,2.ZHANG Lan1,2.& YU Hong1,2.1 State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering,Hohai {2.,{2. 2.0098,China 2.National engineering Research Center of Water Resources Efficient Utilization and engineering Safety,Hohai {2.,{2. 2.0098,China 3.department of Civil,environmental and Geomatic engineering,Swiss Federal Institute of Technology,Zurich 8093.Switzerland 1. State Key Laboratory of Hydrology-Water Resources and Hydraulic engineering Hohai University Nanjing 210098 China2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China3. Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich 8093 Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction

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