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Chemical Research in Chinese Universities 2012年第1期28卷 41-46页

作者： HUA Xiu-yi, LIU Xiao-xue, DONG De-ming, LI Ming and LI Yao-rui key laboratory of Groundwater Resources and environment, ministry of education, key Lab of Water Resources and Aquatic environment of Jilin Province, College of environment and Resources, Jilin University, Changchun 130012, P. R. china Jilin Univ Key Lab Groundwater Resources & Environm Key Lab Water Resources & Aquat Environm Jilin Pr Minist EducColl Environm & Resources Changchun 130012 Peoples R China

Multistage sequential extraction with different sequences was applied to extracting natural surface coa tings（NSCs）, and the results were compared with those by single stage extraction technique. The optimal sequential extraction scheme with the best performance was selected and incorporated into the method of selective extraction followed by adsorption and statistic analyses to study the adsorption parameters of Fe oxides, Mn oxides and organic matters in NSCs for Pb and Cd, to validate the applicability of the sequential extraction scheme. The Langmuir ad sorption parameters of each component of surface coating estimated according to the adsorption data of single stage extraction of NSCs were all similar to those of sequential extraction of NSCs, and the maximum difference between the metal adsorption abilities of the components estimated via the two extraction techniques was only about 20%, in dicating that either extraction techniques could be used. The optimal sequential extraction scheme obtained was first extracted with NH2OH·HCl, then with Na2S2O4, and finally with oxalic acid.

关键词： Natural surface coating(NSC) Sequential extraction Single stage extraction Adsorption Component

Upconversion luminescence properties of Er^(3+) doped GeS_2-Ga_2S_3-KCl chalcohalide glasses

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Rare Metals 2011年第1期30卷 18-21页

作者： ZHANG Jihong TAO Haizheng ZHAO Xiujian key laboratory of Silicate Materials Science and Engineering（ministry of education） Wuhan University of TechnologyWuhan 430070China

Er^3＋ ions doped chalcohalide glasses with the composition of 56GeS2-24Ga2S3-20KCl were fabricated by a melt-quenching *** 800 nm laser excitation,strong green emissions centered at 525 nm and 550 nm and weak red emission centered at 660 nm were observed,which were assigned to ^2H11/2→^4I15/2,^4S3/2→^4I15/2,and ^4F9/2→^4I15/2 transitions,*** intensity reached maximum when the Er^3＋ ions concentration was 0.1 mol%.The possible upconversion luminescence mechanism was proposed from the discussion on the above results as well as the results of lifetimes of the metastable ^4I13/2 level and local environment of Er^3＋ *** is found that chalcohalide glass can be good host materials for upconversion luminescence.

关键词： amorphous materials glass rare earths luminescence doping

Guided wave propagation in multilayered piezoelectric structures

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Science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1094-1104页

作者： GUO YongQiang1, CHEN WeiQiu2,3 & ZHANG YongLiang4 1 key laboratory of Mechanics on Disaster and environment in Western china, ministry of education, and School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, china 2 key laboratory of Soft Soils and Geoenvironmental Engineering, ministry of education, and Department of Civil Engineering, Zhejiang University, Hangzhou 310058, china 3 Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, china 4 School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, china key laboratory of Mechanics on Disaster and environment in Western china Ministry of Education and School of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China key laboratory of Soft Soils and Geoenvironmental Engineering Ministry of Education and Department of Civil Engineering Zhejiang University Hangzhou 310058 China Department of Engineering Mechanics Zhejiang University Hangzhou 310027 China School of Civil Engineering Lanzhou Jiaotong University Lanzhou 730070 China

A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

关键词： multilayered piezoelectric structures the method of reverberation-ray matrix guided waves dispersion characteristic

Analytical method of Cr stable isotope and its application to water pollution survey

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Chinese Science Bulletin 2010年第7期55卷 664-669页

High Cr(VI) concentration is a potential serious risk to environment and ecologic ***,it is essential to effectively monitor Cr contamination in water systems and scientifically evaluate its evolution trend.A new method of in-situ tracer technique by Cr isotopic analysis for quantitatively estimating Cr-contamination and its regional evolution in natural waters as well as a case application are reported in this *** on documented literatures,an experimental procedure for chemical separation and purification of Cr in water samples and its analytical method for Cr isotopic measurement by thermal ionization mass spectrometry(TIMS) are *** samples collected around a chemical factory in Hubei Province were analyzed by this *** samples showδ53Cr values ranging from-1.7‰to 7.3‰and an elevating trend with an increasing in distance from the sampling site to pollution source.A functional correlation following Rayleigh fractionation law was established between sample'sδ53Cr value and its extent of Cr *** study suggests that Cr isotopic analysis is an effective method to reveal the spatial distribution and its evolution trend of Cr contamination in the regional water *** is thus helpful to assessing the self-purifying ability of local water system according to Cr isotopic fractionation.

关键词：铬(VI) 水污染调查稳定同位素应用同位素分析供水系统演变趋势示踪技术

A theoretical model of collision between soft-spheres with Hertz elastic loading and nonlinear plastic unloading

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Theoretical & Applied Mechanics Letters 2011年第4期1卷 34-39页

作者： Youhe Zhou 1,2,a) 1) key laboratory of Mechanics on Disaster and environment in Western china,the ministry of education of china 2)Department of Mechanics and Engineering Science,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,china Department of Mechanics and Engineering Science College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China

This paper presents a theoretical model on the normal(head-on) collision between soft-spheres on the basis of elastic loading of the Hertz contact for compression process and a nonlinear plastic unloading for restitution one,in which the parameters all are determined in terms of the material and geometric ones of the spheres,and the behaviors of perfect elastic,inelastic,and perfect plastic collisions appeared in the classical mechanics are fully described once a value of coefficient of restitution is specified in the region of 0 ≤ ε ≤ *** an empirical formula of the coefficient of restitution dependent on the impact velocity is suggested to fit the existing experimental measurements by means of the least square method,the predictions of the dependency and the collision duration are in well quantitative agreement with their experimental *** is found that the measurable quantities are dependent on both the impact velocity and the parameters of *** this model,finally,an approach to determine the spring coefficient in the linear viscoelastic model of the collision is also *** results obtained here will be significantly beneficial for the applications where a collision model is requested in the simulations of relevant grain flows and impact dynamics etc..

关键词： normal collision of soft-spheres theoretical model residual displacement restitution coefficient collision duration

Test of magnetic susceptibility and grain-size age models of loess

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Progress in Natural Science:Materials International 2007年第11期17卷 1312-1317页

作者： Chen Yimeng1,2,3, Feng Zhaodong4 and Gong Huili1,2(1. MOE and key laboratory of Resources environment and GIS of Beijing, Beijing 100037, china 2. key laboratory of 3D information Acquisition and Application, The Capital Normal University, Beijing 100037, china 3. Department of Economics & Management of Huizhou University, Huizhou 516007, china 4. key laboratory of Western china’s environmental Systems, ministry of education, Lanzhou University, Lanzhou 730000, china) MOE and key laboratory of Resources environment and GIS of Beijing Beijing 100037 China key laboratory of 3D information Acquisition and Application The Capital Normal University Beijing 100037 China Department of Economics & Management of Huizhou University Huizhou 516007 China key laboratory of Western china’s environmental Systems Ministry of Education Lanzhou University Lanzhou 730000 China

Ages of the stratigraphic boundary MIS1/2 and MIS3/4 of the Yuanbu loess section in Linxia are used as the basis of the nodal control age. The age of MIS1/2 and MIS3/4 are obtained from the latest international research result—the climatic events recorded in the stalagmite in the Hulu Cave in Nanjing, that MIS1/2 is 11.5 kaB.P. and MIS3/4 is 59.8 kaB.P.. The ages of the two climatic events contain three nodal age control models (Model 1: 0 kaB.P.—59.8 kaB.P.; Model 2: 0 kaB.P.—11.5 kaB.P. and 11.5 kaB.P.—59.8 kaB.P.; Model 3: 11.5 kaB.P.—59.8 kaB.P.), which are used as the nodal control age separately. The deposition times of various stratigraphic horizons are calculated by using the magnetic susceptibility age model and grain-size age model, and then compared with each other. In addition, the AMS14C age, OSL age and the ages of YD and H events are compared with the ages of the corresponding horizons calculated by the three models of nodal control ages. From the analyses of lithologic characters and climatic stages it has been found that both the magnetic susceptibility age model and the grain-size age model have some defects. Because the accurate control ages are selected as the nodal points of the glacial period or interglacial period, the stratigraphic deposition times determined by the high resolution of magnetic susceptibility age model and grain-size age model approximate to the actual ages. As for the relative accuracy of the two age models, the magnetic susceptibility age model is more accurate than the grain-size age model.

关键词： loess nodal control age magnetic susceptibility age model grain-size age model test

Equations and their physical interpretation in numerical modeling of heavy metals in fluvial rivers

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中国科学：技术科学英文版 2010年第2期53卷 548-557页

作者： HUANG SuiLiang Numerical Simulation Group for Water environment, Tianjin key laboratory of environmental Remediation and Pollution Control, key laboratory of Pollution Processes and environmental Criteria of the ministry of education College of environmental Science and Engineering, Nankai University, Tianjin 300071, china 1. Numerical Simulation Group for Water environment Tianjin Key Laboratory of Environmental Remediation and Pollution Control Key Laboratory of Pollution Processes and Environmental Criteria of the Ministry of Education College of environmental Science and Engineering Nankai University Tianjin 300071 China

Based on the previous work on the transport-transformation of heavy metal pollutants in fluvial rivers, this paper presented the formulation of a two-dimensional model to describe heavy metal transport-transformation in fluvial rivers by considering basic principles of environmental chemistry, hydraulics, mechanics of sediment transport and recent developments along with three very simplified test cases. The model consists of water flow governing equations, sediment transport governing equations, transport-transformation equation of heavy metal pollutants, and convection-diffusion equations of adsorption-desorption kinetics of particulate heavy metal concentrations on suspended load, bed load and bed sediment. The heavy metal transport-transformation equation is basically a mass balance equation, which demonstrates how sediment transport affects transport-transformation of heavy metals in fluvial rivers. The convection-diffusion equations of adsorption-desorption kinetics of heavy metals, being an extension of batch reactor experimental results and a major advancement of the previous work, take both physical transport, i.e. convection and diffusion and chemical reactions, i.e. adsorption-desorption into account. Effects of sediment transport on heavy metal transport-transformation were clarified through three examples. Specifically, the transport-transformation of heavy metals in a steady, uniform and equilibrium sediment-laden flow was calculated by applying this model, and results were shown to be rational. Both theoretical analysis and numerical simulation indicated that the transport-transformation of heavy metals in sediment-laden flows with clay-enriched riverbed possesses not only the generality of common tracer pollutants, but also characteristics of transport-transformation induced by sediment motion. Future work will be conducted to present validation/application of the model with available data.

关键词： heavy metals transport-transformation water-sediment-pollutants interaction fluvial rivers numerical modeling

Carbon distribution and fluxes of 16 rivers discharging into the Bohai Sea in summer

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Acta Oceanologica Sinica 2011年第3期30卷 43-54页

作者： XIA Bin ZHANG Longjun key laboratory of Marine environmental Science and Ecology Ministry of Education Ocean University of China Qingdao 266100 China key laboratory of Sustainable Utilization of Marine Fisheries Resources Ministry of Agriculture Yellow Sea Fisheries Research Institute Chinese Academy of Fisheries Sciences Qingdao 266071 China

Riverine carbon input is closely related to the inshore aquatic environment, the marine carbon pool and climate change. Samples were synchronously obtained from 16 rivers discharging into the Bohai Sea （china） in 1-5 July 2005. The dissolved organic carbon （DOC） concentrations of the 16 rivers were mainly controlled by anthropogenic activities. The particulate organic carbon （POC） of the Haihe, Luanhe, Ziyaxinhe, Chaobaixinhe, Xiaoqinghe, Xiaolinghe, Duliujianhe, Jiyunhe, and Majiahe Rivers mainly originated from pollutants discharged by human, while that of the Huanghe River （Yellow River）, Daliaohe, Shuangtaizihe, Tuhaihe, Dalinghe, Daqinghe, and Liuguhe Rivers were generated mainly by soil erosion. Higher dissolved inorganic carbon （DIC） concentrations in the 16 rivers were detected, which were influenced by the large amounts of carbonate and industrial pollution. The estimated DOC, POC and DIC fluxes from the 16 rivers discharging into the Bohai Sea in summer, 2005 were 0.91×10^5, 1.23×10^5 and 6.31×10^5t, respectively.

关键词： Bohai Sea carbon fluxes dissolved organic carbon particulate organic carbon carbon cycling sources

A Trusted environment Construction Method for Security-Sensitive Software

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wuhan University Journal of Natural Sciences 2011年第5期16卷 383-390页

作者： LI Jing1,2,ZHANG Huanguo1,2,ZHAO Bo1,2,FANG Lingling1,2 1.School of Computer,wuhan University,wuhan 430072,Hubei,china 2.key laboratory of Aerospace Information Security and Trust Computing,ministry of education,wuhan 430072,Hubei,china School of Computer Wuhan University Wuhan Hubei China key laboratory of Aerospace Information Security and Trust Computing Ministry of Education Wuhan Hubei China

This paper presents a trusted-environment construction method based on the underlying hardware. This method aims at protecting the security-sensitive software in the aspects of software loading, running, and storing in the general operating system. It extends the trust chain of the traditional trusted computing technology to reach the target software, ensuring trusted loading. The extended memory management mechanism effectively pre- vents memory dumping and memory tampering for the high-sensitivity data. The file monitoring mechanism protects files from vicious operation made by attackers. Flexible-expanded storage environment provides the target software with static storing protection. Experimental system verifies that the method is suitable for general operating system and can effectively protect security-sensitive software with low overhead.

关键词： information security trusted computing securitysensitive software trusted environment

Advances in numerical methods for the solution of population balance equations for disperse phase systems

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Science china Chemistry 2009年第8期52卷 1063-1079页

作者： SU JunWei1,GU ZhaoLin2,3 & XU X.Yun41 Department of Mechanical Engineering and Automation,School of Mechanical Engineering,Xi’an Jiaotong University,Xi’an 710049,china 2 key laboratory of Mechanics on Disaster and environment in Western china,ministry of education,Lanzhou 730000,china 3 Department of environmental Science and Technology,School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,china 4 Department of Chemical Engineering,Imperial College London,London SW7 2AZ,UK 1. Department of Mechanical Engineering and Automation School of Mechanical Engineering Xi’an Jiaotong University Xi’an 710049 China 2. key laboratory of Mechanics on Disaster and environment in Western china Ministry of Education Lanzhou 730000 China 3. Department of environmental Science and Technology School of Human Settlements and Civil Engineering Xi’an Jiaotong University Xi’an 710049 China 4. Department of Chemical Engineering Imperial College London London SW7 2AZ UK

Accurate prediction of the evolution of particle size distribution is critical to determining the dynamic flow structure of a disperse phase system.A population balance equation(PBE),a non-linear hyperbolic equation of the number density function,is usually employed to describe the micro-behavior(aggregation,breakage,growth,etc.) of a disperse phase and its effect on particle size *** solution is the only choice in most *** this paper,three different numerical methods(direct discretization methods,Monte Carlo methods,and moment methods) for the solution of a PBE are evaluated with regard to their ease of implementation,computational load and numerical *** attention is paid to the relatively new and superior moment methods including quadrature method of moments(QMOM),direct quadrature method of moments(DQMOM),modified quadrature method of moments(M-QMOM),adaptive direct quadrature method of moments(ADQMOM),fixed pivot quadrature method of moments(FPQMOM),moving particle ensemble method(MPEM) and local fixed pivot quadrature method of moments(LFPQMOM).The prospects of these methods are discussed in the final section,based on their individual merits and current state of development of the field.

关键词： population balance equation direct discretization method Monte Carlo method moment methods disperse phase system