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Discontinuous Galerkin Methods for Distributed Control Problems of a Scalar Hyperbolic Equation

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Discontinuous Galerkin Methods for Distributed Control Probl...

A NEW FINITE ELEMENT APPROXIMATION OF A STATE-CONSTRAINED OPTIMAL CONTROL PROBLEM

第二十九届中国控制会议

作者： CHANG Lili,gong wei,yan ningning Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,P.R.China

In this paper,we study the numerical approximation of distributed control problems for a scalar hyperbolic *** on a Discontinuous Galerkin scheme,we establish a numerical approximation of the underlying optimal control *** give a priori error analysis and obtain optimal order of convergence for both state and optimal *** experiments confirm the theoretical results we obtained.

关键词： Optimal Control Problem Control Constraints Discontinuous Galerkin Method A Priori Error Estimate Transport-Reaction Equation

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Journal of Computational Mathematics 2009年第1期27卷 97-114页

作者： Wenbin Liu wei gong ningning yan KBS Institute of Mathematics and Statistics The University of Kent Canterbury CT2 7NF England LSEC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

In this paper, we study numerical methods for an optimal control problem with pointwise state constraints. The traditional approaches often need to deal with the deltasingularity in the dual equation, which causes many difficulties in its theoretical analysis and numerical approximation. In our new approach we reformulate the state-constrained optimal control as a constrained minimization problems only involving the state, whose optimality condition is characterized by a fourth order elliptic variational inequality. Then direct numerical algorithms （nonconforming finite element approximation） are proposed for the inequality, and error estimates of the finite element approximation are derived. Numerical experiments illustrate the effectiveness of the new approach.

关键词： Optimal control problem State-constraints Fourth order variational inequalities Nonconforming finite element method.

AN IMPROVED ERROR ANALYSIS FOR FINITE ELEMENT APPROXIMATION OF BIOLUMINESCENCE TOMOGRAPHY

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Journal of Computational Mathematics 2008年第3期26卷 297-309页

作者： wei gong Ruo Li ningning yan weibo Zhao Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China CAPT LMAM and School of Mathematical Sciences Peking University Beijing 100871 China LSEC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China School of Mathematical Sciences Peking University Beijing 100871 China

This paper is concerned with an ill-posed problem which results from the area of molecular imaging and is known as BLT problem. Using Tikhonov regularization technique, a quadratic optimization problem can be formulated. We provide an improved error estimate for the finite element approximation of the regularized optimization problem. Some numerical examples are presented to demonstrate our theoretical results.

关键词： BLT problem Tikhonov regularization Optimization problem A priori error estimate

Effect of Long-Term Fertilization on Soil Productivity on the North China Plain

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Pedosphere 2015年第3期25卷 450-458页

作者： WANG Jing-yan yan Xiao-Yuan gong wei Sichuan Provincial Key Laboratory of Ecological Forestry Engineering Sichuan Agricultural University State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of Sciences

Soil productivity is the ability of a soil, in its normal environment, to support plant growth and can be evaluated with respect to crop production in unfertilized soil within the agricultural ecosystem. Both soil productivity and fertilizer applications affect crop yields. A long-term experiment with a winter wheat-summer maize rotation was established in 1989 in a field of the Fengqiu State Key Agro-Ecological Experimental Station, a region typical of the North China Plain, including seven treatments： 1） a balanced application of NPK chemical fertilizers （NPK）; 2） application of organic fertilizer （OM）; 3） application of 50% organic fertilizer and 50% NPK chemical fertilizers （1/2OMN）; 4） application of NP chemical fertilizers （NP）; 5） application of PK chemical fertilizer （PK）; 6） application of NK chemical fertilizers （NK）; and 7） unfertilized control （CK）. To investigate the effects of fertilization practices on soil productivity, further pot tests were conducted in 2007-2008 using soil samples from the different fertilization treatments of the long-term field experiment. The soil sample of each treatment of the long-term experiment was divided into three pots to grow wheat： with no fertilization （Potunf）, with balanced NPK fertilization （POtNPK）, and with the same fertilizer（s） of the long-term field experiment （Potori）. The fertilized soils of the field experiment used in all the pot tests showed a higher wheat grain yield and higher nutrient uptake levels than the unfertilized soil. Soil productivity of the treatments of the field experiment after 18 years of continuous fertilizer applications were ranked in the order of OM 〉 1/2OMN 〉 NPK 〉 NP 〉 PK 〉 NK 〉 CK. The contribution of soil productivity of the different treatments of the field experiment to the wheat grain yield of Potori was 36.0%-76.7%, with the PK and NK treatments being higher than the OM, 1/2OMN, NPK, and NP treatments since the soil in this area was deficient in N and P and rich in K. Wheat g

关键词： balanced fertilization chemical fertilizer crop yield soil fertility nutrient use efficiency organic fertilizer soil organic matter

Numerical Study of Wetting Transitions on Biomimetic Surfaces Using a Lattice Boltzmann Approach with Large Density Ratio

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Journal of Bionic Engineering 2017年第3期14卷 486-496页

作者： wei gong Yuying yan Sheng Chen Donald Giddings Fluids & Thermal Engineering Research Group Faculty of Engineering University of Nottingham University Park Nottingham NG7 2RD UK Center for Fluids & Thermal Engineering University of Nottingham Ningbo China

The hydrophobicity of natural surfaces has drawn much attention of scientific communities in recent years. By mimicking natural surfaces, the manufactured biomimetic hydrophobic surfaces have been widely applied to green technologies such as self-cleaning surfaces. Although the theories for wetting and hydrophobicity have been developed, the mechanism of wetting transitions between heterogeneous wetting state and homogeneous wetting state is still not fully clarified. As understanding of wetting transitions is crucial for manufacturing a biomimetic superhydrophobic surface, more fundamental discussions in this area should be carried out. In the present work, the wetting transitions are numerically studied using a phase field lattice Boltzmann approach with large density ratio, which should be helpful in understanding the mechanism of wetting transitions. The dynamic wetting transition processes between Cassie-Baxter state and Wenzel state are presented, and the energy barrier and the gravity effect on transition are discussed. It is found that the two wetting transition processes are irreversible for specific inherent contact angles and have different transition routes, the energy barrier exists on an ideally patterned surface and the gravity can be crucial to overcome the energy barrier and trigger the transition.

关键词： wetting transitions biomimetic surfaces energy barrier gravity effect numerical study lattice Boltzmann method

Wetting transition energy curves for a droplet on a square-post patterned surface

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Science Bulletin 2017年第2期62卷 136-142页

作者： wei gong Yingqing Zu Sheng Chen Yuying yan Fluids & Thermal Engineering Research Group Faculty of Engineering University of Nottingham Department of Aeronautics and Astronautics Fudan University

Due to the property of water repellence, biomimetic superhydrophobic surfaces have been widely applied to green technologies, in turn inducing wider and deeper investigations on superhydrophobic surfaces. Theoretical, experimental and numerical studies on wetting transitions have been carried out by researchers, but the mechanism of wetting transitions between Cassie-Baxter state and Wenzel state, which is crucial to develop a stable superhydrophobic surface, is still not fully understood. In this paper, the flee energy curves based on the transition processes are presented and discussed in detail. The exis- tence of energy barriers with or without consideration of the gravity effect, and the irreversibility of wet- ting transition are discussed based on the presented energy curves. The energy curves show that different routes of the Cassie-to-Wenzel transition and the reverse transition are the main reason for the irre- versibility. Numerical simulations are implemented via a phase field lattice Boltzmann method of large density ratio, and the simulation results show good consistency with the theoretical analysis.

关键词： Wetting transition Energy curves Lattice Boltzmann method

Effect of Different Ionic Liquids on 5-Hydroxymethylfurfural Preparation from Glucose in DMA over AlCl_(3):Experimental and Theoretical Study

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Chinese Journal of Chemistry 2015年第5期33卷 583-588页

作者： yan yang Wentao Liu ningning Wang Haijun Wang wei Li Zhanxin Song Key Laboratory of Food Colloids and Biotechnology Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxiJiangsu 214122China

In this work,effect of different ionic liquids(ILs)on 5-hydroxymethylfurfural(HMF)preparation from glucose in N,N-dimethylacetamide(DMA)over AlCl3 was revealed by a combined experimental and computational *** used as cocatalysts in this work included N-methyl-2-pyrrolidone hydrogen sulfate([NMP]HSO_(4)),N-methyl-2-pyrrolidone methyl sulfate([NMP]CH_(3)SO_(3)),N-methyl-2-pyrrolidone chlorine([NMP]Cl)and N-methyl-2-pyrrolidone bromide([NMP]Br)which were endowed with the same cation but different *** to the conclusion that fructose was intermediate product from glucose to HMF,we found fructose was transformed to more by-products by[NMP]H_(S)O_(4),making HMF yield decline significantly when glucose was treated as *** glucose nor fructose could be converted by[NMP]CH_(3)SO_(3)efficiently,leading to its no influence on glucose conversion to HMF.[NMP]Br had a higher selectivity for HMF from fructose than[NMP]Cl and ***,Al^(3+)preferred to combine with Br−,slightly decreasing both the overall free energy barrier for glucose isomerization and activation barrier for H-shift at 393.15 *** a high HMF yield of 57%was obtained from glucose catalyzed by AlCl3 together with[NMP]Br under mild conditions.

关键词： anions quantum chemistry complex glucose isomerization H-shift

Durability of Concrete with Different Improvement Measures and Its Ser-vice Life Prediction in Island and Reef Environment

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China Ocean Engineering 2022年第6期36卷 947-958页

作者： gong wei YU Hong-fa MA Hai-yan WANG Nan ZHU Hai-wei School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212100China Department of Civil and Airport Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Civil Engineering University of Science and Technology LiaoningAnshan 114051China Key Laboratory of Harbor and Marine Structure Durability Technology of the Ministry of Communications CCCC Forth Harbor Engineering Institute Co.Ltd.Guangzhou 510230China

To solve the durability of island and reef concrete engineering in the harsh environment of high temperature,high salt,high humidity and windy,the strength grade of concrete and the type of corrosion inhibitor were used as the influence factors,while the relative dynamic elastic modulus was used as the evaluation *** addition,the law and time variability of the deterioration of concrete,the size effect,environmental similarity and the service life model were *** results showed that improving the strength grade of concrete could improve the durability of concrete,and corrosion inhibitor could slightly improve the durability of ***-varying law of the deterioration of concrete conformed to the univariate quadratic *** with the concrete damage equivalent theory,a size effect model based on the relative dynamic elastic modulus was proposed and verified,and the size effect coefficient was also *** environmental similarity model between simulated and practical island and reef environment was *** with the reliability theory and the first order second moment method,a new service life model of concrete structure was *** authors were convinced that the research will be advantageous to researchers.

关键词： island and reef environment relative dynamic elastic modulus size effect environmental similarity service life model

Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis

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International Journal of Ophthalmology(English edition) 2017年第9期10卷 1436-1445页

作者： Huan yan Li-yan gong wei Huang yan-Li Peng Department of Ophthalmology the Second Affiliated Hospital of Chongqing Medical University Chongqing Medical University Department of Ophthalmology Chongqing Aier-Mega Eye Hospital Aier Eye Hospital Group Aier School of Ophthalmology Central South University

AIM：To evaluate the possible differences in visual quality between small incision lenticule extraction（SMILE）and femtosecond laser in situ keratomileusis（FS-LASIK）for ***：A Meta-analysis was *** were from previously reported comparative studies treated with SMILE versus *** Pub Med,EMBASE,Cochrane,Web of Science and Chinese databases（*** and CNKI）were searched in *** 2016 using Rev Man 5.1 version *** differences in visual acuity,aberration and biomechanical effects within six months postoperatively were ***-seven studies including 4223 eyes were ***：No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery（P=0.14）,the proportion of eyes achieving an uncorrected distance visual acuity of 20/20or better（P=0.43）,the final refractive spherical equivalent（P=0.89）,the refractive spherical equivalent within±1.00diopter of the target values（P=0.80）,vertical coma（P=0.45）and horizontal coma（P=0.06）.Compared with the FSLASIK group,total higher-order aberration（P〈0.001）and spherical aberration（P〈0.001）were higher and the decrease in corneal hysteresis（P=0.0005）and corneal resistance factor（P=0.02）were lower in the SMILE ***：SMILE and FS-LASIK are comparable in efficacy,safety and predictability for correcting ***,the aberration in the SMILE group is superior to that in the FS-LASIK group,and the loss of biomechanical effects may occur less frequently after SMILE than after FS-LASIK.

关键词： Meta-analysis small incision lenticuleextraction femtosecond laser in situ keratomileusis myopia