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TWO-SCALE CURVED ELEMENT METHOD FOR ELLIPTIC PROBLEMS WITH SMALL PERIODIC COEFFICIENTS

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Journal of Computational Mathematics 2002年第4期20卷 381-390页

作者： Jin-ru Chen Jun-zhi cui School of Mathematics and Computer Sciences Nanjing Normal UniversityNanjing 210097China LSEC ICMSECAcademy of Mathematics and System SciencesChinese Academy of SciencesBeijing 100080China

This paper is concerned with the second order elliptic problems with small periodic coefficients on a bounded domain with a curved boundary. A two-scale curved element method which couples linear elements and isoparametric elements is proposed. The error estimate is obtained over the given smooth domain. Furthermore an additive Schwarz method is provided for the isoparametric element method.

关键词： two-scale curred element small periodic coefficients

Multivariate statistical analysis for the surface water quality of the Luan River,China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 142-148页

作者： zhi-wei ZHAO Fu-yi cui State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China

In order to analyze the characteristics of surface water resource quality for the reconstruction of old water treatment plant,multivariate statistical techniques such as cluster analysis and factor analysis were applied to the data of Yuqiao Reservoir-surface water resource of the Luan River,*** results of cluster analysis demonstrate that the months of one year were divided into 3 groups and the characteristic of clusters was agreed with the seasonal characteristics in North *** factors were derived from the complicated set using factor *** 1 included turbidity and chlorophyll,which seemed to be related to the anthropogenic activities;factor 2 included alkaline and hardness,which were related to the natural characteristic of surface water;and factor 3 included Cl and NO2-N affected by mineral and agricultural *** sinusoidal shape of the score plots of the three factors shows that the temporal variations caused by natural and human factors are linked to seasonality.

关键词： Surface water quality Cluster analysis Factor analysis Temporal variation of scores

Interfacial Chain Entanglements Induced Melt Memory Effect in Poly(ε-caprolactone)/Silica Nanocomposites

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Chinese Journal of Polymer Science 2022年第11期40卷 1451-1465页

作者： Xiang Liu Wen-zhi cui Wei Yu Advanced Rheology Institute Department of Polymer Science and EngineeringShanghai Key Laboratory of Electrical Insulation and Thermal AgeingState Key Laboratory for Metal Matrix Composite MaterialsShanghai Jiao Tong UniversityShanghai200240China

It is known that the enhanced melt memory effect is strongly correlated with the retarded chain ***,previous studies using differential scanning calorimetry(DSC)showed a weakened or even vanished melt memory in polymer nanocomposites,although adding nanoparticles in polymers often reduces chain *** this work,we added two kinds of silica nanoparticles,O15 and W22 nanoparticles(with low and high surface silanol density,respectively),to poly(ε-caprolactone)(PCL),where the degree of chain entanglements near nanoparticles increases,and chain dynamics is gradually retarded with increasing silica *** strongly aggregated W22 nanoparticles show significant heterogeneous nucleation,while well-dispersed O15 nanoparticles exhibit very weak heterogeneous *** contrast to the restrained self-nucleation effects during the rapid non-isothermal crystallization of two nanocomposites,we found evident melt memory effects during the slow isothermal crystallization in PCL/O15 nanocomposites as indicated by DSC and polarized light microscopy(PLM)*** melt memory becomes stronger with more O15 nanoparticles,but depends non-monotonically on the loadings of W22 *** lifetime of the melt memory effects matches the chain re-entanglement time of the SN melts of nanocomposites,which is consistent with our previous work on PCL miscible *** complicated influence of silica on nucleation and crystal growth is induced by the spatial inhomogeneity of chain entanglements in the silica-filled PCL *** decrease in the entanglement density of the interfacial chains in the SN melts of nanocomposites is conducive to nucleate under slow isothermal crystallization,but the chain mobility is still greatly restrained by the nanoparticles,causing the slow growth rate of spherulites and the difficulty to form nuclei under fast non-isothermal crystallization.

关键词： PCL Silica nanocomposite Self-nucleation crystallization

Predicting Critical Conditions and Stress-Strain Curves for Dynamic Recrystallization in SPHC Steel

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Journal of Iron and Steel Research International 2010年第7期17卷 51-57页

作者： WU Lai-zhi LI Xue-song CHEN Jun ZHANG hong-bing cui Zhen-shan Department of Plasticity Technology Shanghai Jiaotong University Shanghai 200030 China

The hot compression tests on an SPHC steel were carried out in the temperature range of 900-1150 ℃ and strain rate range of 0.1-10 s-1,in which the maximum true strain is *** activation energy of test steel was calculated,to be 299.4 kJ/*** critical stresses and strains for initiation of dynamic recrystallization were determined based on changes of the work hardening rate（θ）as a function of the flow stress（σ）or strain（ε）,*** dependence of the peak strain（εp）,the peak stress（σp）,and the steady state stress（σs）were determined based on the Zener-Hollomen *** mathematical models of the flow stress evolution were established in the hardening and dynamic recovery region and dynamic recrystallization region,*** average error between experimental curves and predicted ones was around 3.26%.

关键词： flow stress dynamic recrystallization critical stress critical strain SPHC steel

Visualizing diffusion tensor fields on streamsurfaces with merging ellipsoids

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Applied Mathematics(A Journal of Chinese Universities) 2014年第4期29卷 399-409页

作者： SONG Wei-jie CHEN Wei CHEN Hai-dong ZHENG hong-chan cui Jun-zhi School of Science Northwestern Polytechnical University State Key Lab of CADCG Zhejiang University Academy of Mathematics and System Sciences Chinese Academy of Sciences

Streamsurfaces in diffusion tensor fields are used to represent structures with pri- marily planar diffusion. So far, however, no effort has been made on the visualization of the anisotropy of diffusion on them, although this information is very important to identify the problematic regions of these structures. We propose two methods to display this anisotropy information. The first one employs a set of merging ellipsoids, which simultaneously character- ize the local tensor details - anisotropy - on them and portray the shape of the streamsurfaces. The weight between the streamsurfaces continuity and the discrete local tensors can be inter- actively adjusted by changing some given parameters. The second one generates a dense LIC （line integral convolution） texture of the two tangent eigenvector fields along the streamsurfaces firstly, and then blends in some color mapping indicating the anisotropy information. For high speed and high quality of texture images, we confine both the generation and the advection of the LIC texture in the image space. Merging ellipsoids method reveals the entire anisotropy information at discrete points by exploiting the geometric attribute of ellipsoids, and thus suits for local and detailed examination of the anisotropy; the texture-based method gives a global representation of the anisotropy on the whole streamsurfaces with texture and color attributes. To reveal the anisotropy information more efficiently, we integrate the two methods and use them at two different levels of details.

关键词： visualization anisotropy diffusion tensor field streamsurface merging ellipsoid LIC.

Surface-enhanced Raman Scattering Effect of Ordered Gold Nanoparticle Array for Rhodamine B with Different Morphologies

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Chinese Journal of Polymer Science 2015年第10期33卷 1470-1476页

作者： Xi-hong Zu zhi-hui Jian 易国斌 Hai-liang Huang Ben-bin Zhong hong-sheng Luo Jia-rong Huang cui Wang School of Chemical Engineering and Light Industry Guangdong University of Technology

In this study, well-ordered gold nanoparticle array on silicon substrate was adopted as an active surface-enhanced Raman scattering substrate for detecting rhodamine B （RB）, and the influence of RB morphologies on surface-enhanced Raman scattering （SERS） properties was discussed. The Au nanoparticle array was prepared by using patterned P4VP nanodomains of poly（styrene-b-4-vinylpyridine）（PS-b-P4VP） diblock copolymer thin films as nanoreactors which is a simple and economical approach. The results show that Raman spectra of RB on the Au nanopaticle array have much stronger intensity than those on the bare silicon substrate by detecting same RB solution. It indicates that the prepared Au nanoparticle array on silicon substrate has a significant Raman enhancement for RB. Interestingly, the Raman intensity of RB from its ethanol solution is much stronger than that from its aqueous solution due to the special morphologies of RB formed in their ethanol solutions. This work provides an effective approach to prepare highly sensitive and stable surface-enhanced Raman scattering substrate.

关键词： Nanoparticle array Rhodamine B Raman spectroscopy Nanowire Nanograss

Facile synthesis and properties of alkali-clearable azo disperse dye containing a carboxylic ester moiety

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Chinese Chemical Letters 2014年第8期25卷 1121-1124页

作者： zhi-Hua cui Xiao-hong Cheng Xin Li hong-Hui Lu Xi-Dong Wang Wei-Guo Chen Engineering Research Center for Eco-Dyeing & Finishing of Textiles Ministry of Education of China Zhejiang Sci-Tech University Key Laboratory of Advanced Textile Materials and Manufacturing Technology Ministry of Education of China Zhejiang Jihua Group Co. Ltd.

A yellow, alkali-clearable azo disperse dye containing a carboxylic ester moiety was readily synthesized from the reactant p-aminobenzoic acid by successive diazotization, coupling reaction, chlorination and esterification with ethanol. Then its molecular structure was characterized by FTIR,1H NMR,13 C NMR,mass spectrometry and elemental analysis. The synthesized dye and a similar control dye containing the acylamide moiety（I） were applied to dyeing poly（ethylene terephthalate） fabric and their washing and rubbing fastness properties with different post-treatment methods（reduction clearing and alkali clearing） were examined and compared. It is found that the ester-containing disperse dye shows good alkali-clear ability on poly（ethylene terephthalate） fabric and contaminates little to environment due to the absence of reductants, as well as low toxicity and easy recycling of the hydrolysates.

关键词： Alkali-clearable Synthesis Carboxylic ester Disperse dye PET

Modes of multi-mechanistic gas diffusion in shale matrix at varied effective stresses:Observations and analysis

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Petroleum Science 2023年第5期20卷 2908-2920页

作者： Tian-Yu Chen Yan-Yu Hao Derek Elsworth hong-Ming Zhang zhi-Ming Hu Guang-Lei cui Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina National Energy Shale Gas R&D(experiment)Center Langfang065007HebeiChina Department of Energy and Mineral Engineering EMS Energy Institute and G3 CenterPennsylvania State UniversityUniversity ParkPA16802USA Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China

Gas diffusion in the shale matrix has a dominant effect on late-stage production from shale gas ***,adequate research on the mechanisms and contributions of gas diffusion for varied pore size populations in shale matrix under recreated in situ stress is *** report gas-diffusion measurements under constant in situ stress but variable gas pressures for contrasting non-adsorbent(helium(He))and adsorbed(methane(CH_(4)))gases to investigate the impact of effective stress on the evolution of dominant mechanisms of *** intact sample replicates true pore-network topology and diffusion *** integrated diffusion model is proposed that combines the effects of slip flow,Knudsen flow,and surface diffusion to constrain the evolution of these flow regimes and their respective contributions to the observational ***,a probability density function(PDF)is employed to separate the gas content distributions of macropores and micropores from the total gas content and to investigate gas contributions in various *** results reveal that the diffusion coefficients of both He and CH_(4) in macropores and micropores increase with gas pressure but decrease with increasing effective *** diffusion coefficients of He and CH_(4) are different in macropores but remain nearly the same in *** diffusion coefficients of slip flow and surface diffusion increase with decreasing effective stress except for CH_(4) diffusion in the micropores,while the evolution of Knudsen diffusion shows the opposite *** flow plays a dominant role in He and CH_(4) diffusion within macropores(pore size 45 nm).Knudsen diffusion gradually becomes significant for He diffusion in the micropores(pore size 4 nm),conversely,for CH_(4) diffusion in the micropores,surface diffusion becomes *** to gas production from reservoirs,the contributions of the micropores will increase gradually with the duration of gas recovery,indicating the significan

关键词： Diffusion coefficient In situ stress Varied pore types Diffusion mechanisms Gas-content contributions

A New Rainwater Harvesting and Recycling System for Transforming Sloping Land into Terraced Farmland

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Journal of Mountain Science 2014年第1期11卷 205-214页

作者： SHI Yuan-zhi WANG Yue-hong cui Yuan-lai WANG Shi-wu ZHANG Yu-shuai State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Water Resources and Hydropower Bureau of Fuyang City Zhejiang Institute of Hydraulics and Estuary

Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil *** paper introduces a new system based on rainwater harvesting and recycling technology,which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer *** new system consists of three subsystems：1） A plough layer with the dual function of crop cultivation and rainwater harvesting; 2） A tank below the plough layer for storing water; 3） An irrigation-drainage *** plough layer and the storage tank,both treated for reducing seepage,are connected through the irrigation and drainage *** showed that,compared with the traditional paddy fields,rice evapotranspiration（ and crop coefficient） in the test field remained at a similar level,while the irrigation amount was reduced by 44.3% under the condition of basin irrigation,and the drainage amount decreased by 86.6%,and the non-point source pollution was reduced to 67.7%~87.9%,and the rainwater utilization efficiency increased by 30% and reached 95.4%,and crop yield of middle-season rice reached 9,975 kg/hm2,which was only 0.4% lower than that in the traditional paddy field in the terms of dry *** new technology sheds light on new possibilities for transformation of hilly sloping land.

关键词： Hills Sloping land Terraced farmland Rainwater harvesting Recycling