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Chemical Research in Chinese Universities 2003年第1期19卷 85-88页

作者： CHEN Yi qing SUN duo xian LIU jun HUANG ya qing School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072P.R.China

Inhomogeneous calcium alginate ion cross\|linking gel microspheres, a novel ion absorbent, were prepared by dropping a sodium alginate solution to a calcium chloride solution via an electronic droplet generator. Calcium alginate microspheres have uniform particle sizes, a smooth surface and a microporous structure. The electrode probe reveals the inhomogeneous distribution of calcium ions with the highest concentration on the surface, and the lowest concentration in the cores of the spheres. As a novel ion adsorbent, calcium alginate gel microspheres have a lower limiting adsorption mass concentration, a higher enrichment capacity and a higher adsorption capacity for Pb 2+ than usual ion exchange resins. The highest percentage of the adsorption is 99 79%. The limiting adsorption mass concentration is 0 0426 mg/L. The adsorption capacity for Pb 2+ is 644 mg/g. Calcium alginate gel microspheres have a much faster ion exchange velocity than D418 chelating resin and D113 polyacrylate resin. The moving boundary model was employed to interpret the ion exchange kinetics process, which indicates that the ion exchange process is controlled by intraparticle diffusion of adsorbable ions. So the formation of inhomogeneous gel microspheres reduces the diffusion distance of adsorbable ions within the spheres and enhances the ion exchange velocity. Alginate has a higher selectivity for Pb 2+ than for Ca 2+ and the selectivity coefficient K Pb Ca is 316. As an ion cross\|linking gel, calcium alginate inhomogeneous microspheres can effectively adsorb heavy metal Pb 2+ at a higher selectivity and a higher adsorption velocity. It is a novel and good ion adsorbent.

关键词： Alginate Inhomogeneous microsphere Adsorption Mechanism

Self-Consistent Sources Extensions of Modified Differential-Difference KP Equation

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Communications in Theoretical Physics 2018年第4期69卷 357-366页

作者： Gegenhasi ya-Qian Li duo-duo Zhang School of Mathematical Sciences Inner Mongolia University Hohhot 010021 China

In this paper, we investigate a modified differential-difference KP equation which is shown to have a continuum limit into the m KP equation. It is also shown that the solution of the modified differential-difference KP equation is related to the solution of the differential-difference KP equation through a Miura transformation. We first present the Grammian solution to the modified differential-difference KP equation, and then produce a coupled modified differential-difference KP system by applying the source generation procedure. The explicit N-soliton solution of the resulting coupled modified differential-difference system is expressed in compact forms by using the Grammian determinant and Casorati determinant. We also construct and solve another form of the self-consistent sources extension of the modified differential-difference KP equation, which constitutes a B?cklund transformation for the differentialdifference KP equation with self-consistent sources.

关键词： modified differential-difference KP equation source generation procedure determinant solution Backlund transformation

Influence of Nd and Y additions on the corrosion behaviour of extruded Mg-Zn-Zr alloys

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 203-209页

作者： Jian-wei Chang jun duo ya-zhen Xiang Hai-yan yang Wen-jiang Ding Ying-hong Peng School of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200240 China School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China School of Mechanical Engineering Qinghai University Xining 810086 China School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

To improve the corrosion resistance of wrought magnesium alloys through rare earth （RE） additions, the corrosion behaviour of Mg-5Zn-0.3Zr-xNd （x=0, 1, and 2; wt%） and Mg-5Zn-0.3Zr-2Nd-yY （y=0.5 and 1; wt%） alloys in a 5wt% NaCl solution was investigated using immersion test and electrochemical measurements. The results of immersion test show that Mg-5Zn-0.3Zr-2Nd alloy exhibits the best corrosion resistance among the tested alloys. Electrochemical measurements show that secondary phases in RE-containing Mg-5Zn-0.3Zr alloys behave as less noble cathodes in micro-galvanic corrosion and suppress the cathodic process. The additions of Nd and Y into Mg-5Zn-0.3Zr alloy also improve the compactness of the corrosion product film and are beneficial to the corrosion resistance.

关键词： magnesium alloys corrosion resistance rare earth additions electrochemical properties neodymium yttrium

Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge duo Xu Xiao Feng Xing yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao Yong Du Zhe Sun Weilin Xu Jian Fang College of Textile and Clothing Engineering Soochow UniversitySuzhou 215123People’s Republic of China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China Department of Electrical and Computer Engineering University of MassachusettsAmherstMA 01003USA Department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK College of Textile Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and Engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion

Directed Evolution of L-Aspartase by Mobility of Domains

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Chemical Research in Chinese Universities 2004年第1期20卷 50-54页

作者： GOUXiao-jun LIShuang KONGXiang-duo LIUWei SUNyan-hong ZHANGJin TheJointLaboratoryofMolecularEvolutionandEngineering DepartmentofBioengineeringChengduUniversityChengdu610106P.R.China KeyLaboratoryforMolecularEnzymologyandEngineeringofMinistryofEducation JilinUniversityChangchun130023P.R.China

To enhance the relative movement of domains, we inserted a random sequence of fifteen-peptide into the three domains of L-aspartase. By means of directed screening, the three isoforms of monomeric, dimmeric and tetrameric enzymes were obtained. Compared to the wild-type tetrameric L-asparease, these mutants remained 19.7%, 42.3%, and 92% of the enzyme activity, respectively. Moreover, the examination of enzyme properties revealed that their k_ cat and K_M changed in varying degrees, and the optimum pH shifted towards acidic pH, while the dependence of the activity of enzyme on Mg 2+ concentration and thermostability increased. Therefore this strategy provides a novel approach to directed evolution of enzymes.

关键词： Directed evolution Domain L-aspartase Mobility

How to identify dislocations in molecular dynamics simulations?

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Science China(Physics,Mechanics & Astronomy) 2014年第12期57卷 2177-2187页

作者： LI duo WANG Feng Chao yaNG Zhen Yu ZHAO ya Pu State Key Laboratory of Nonlinear Mechanics (LNM) Institute of Mechanics Chinese Academy of Sciences Department of Modern Mechanics University of Science and Technology of China Institute of Solid Mechanics Beihang University

Dislocations are of great importance in revealing the underlying mechanisms of deformed solid *** the development of computational facilities and technologies,the observations of dislocations at atomic level through numerical simulations are *** dynamics(MD)simulation suggests itself as a powerful tool for understanding and visualizing the creation of dislocations as well as the evolution of crystal ***,the numerical results from the large-scale MD simulations are not very illuminating by themselves and there exist various techniques for analyzing dislocations and the deformed crystal ***,it is a big challenge for the beginners in this community to choose a proper method to start their *** this review,we summarized and discussed up to twelve existing structure characterization methods in MD simulations of deformed crystal solids.A comprehensive comparison was made between the advantages and disadvantages of these typical *** also examined some of the recent advances in the dynamics of dislocations related to the hydraulic *** was found that the dislocation emission has a significant effect on the propagation and bifurcation of the crack tip in the hydraulic fracturing.

关键词： dislocations defects MD simulation structural characterization hydraulic fracturing (fracking)

Numerical model and hydrodynamic performance of tuna finlets

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Theoretical & Applied Mechanics Letters 2022年第1期12卷 56-64页

作者： jun-duo Zhang Wei-Xi Huang AML Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

Finlets, a series of small individual triangular fins located along the dorsal and ventral midlines of the body, are remarkable specializations of tuna and other scombrid fishes capable of high-speed swimming. In this study, a symmetric model containing nine finlets of tuna is proposed to overcome the limitation of measurement without losing authenticity. Hydrodynamic performance along with three-dimensional flow structures obtained by direct numerical simulation are demonstrated to disclose the underlying hydrodynamics mechanism of finlets. Complex interactions of leading-edge vortices(LEVs), trialing-edge vortices(TEVs), tip vortices(TVs) and root vortices(RVs) are observed from the three-dimensional vortical structures around the finlets. Two more cases consisting of the 3rd to 9th(without the first two) and the 3rd to 7th(without the first two and the last two) finlets are also simulated to examine the effects of the first two and the last two finlets.

关键词： Tuna Finlets Thunniform swimming Leading-edge vortex Vortex interactionw

High-level expression and purification of Plutella xylostella acetylcholinesterase in Pichia pastoris and its potential application

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Journal of Integrative Agriculture 2017年第6期16卷 1358-1366页

作者： LIU Niu CHE jun LAI duo WEN Jin-jun XU Han-hong State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources & Key Laboratory of Natural Pesticide and Chemical Biology Ministry of Education/South China Agricultural University Guangzhou 510642 P.R.China Shenzhen Longgang Inspection Station of Non-pollution Agricultural Products Shenzhen 510172 P.R. China Institute of Fruit Tree Research Guangdong Academy of Agricultural Sciences Guangzhou 510640 P.R. China

The acetylcholinesterase 2（AChE2）cloned from Plutella xylostella was first successfully expressed in methylotrophic yeast Pichia pastoris *** transformant with high-level expression of the recombinant AChE（rAChE,23.2 U mL-1in supernatant）was selected by plating on increasing concentrations of antibiotic G418 and by using a simple and specific chromogenic reaction with indoxyl acetate as a *** maximum production of r ACh E reached about 11.8 mg of the enzyme protein per liter of *** r ACh E was first precipitated with ammonium sulfate（50%saturation）and then purified with procainamide affinity column *** enzyme was purified 12.1-fold with a yield of 22.8%and a high specific activity of 448.3 U *** was sensitive to inhibition by methamidophos and pirimicarb,the calculated 50% inhibitory concentration（IC50）values of the two pesticides were 0.357 and 0.888 mg L-1,respectively,and the calculated 70% inhibitory concentration（IC70）values were 0.521 and 0.839 mg L-1,*** results suggested that it has a potential application in the detection of pesticide residues.

关键词： Plutella xylostella acetylcholinesterase Pichia pastoris high-level expression

Conductance and dielectric properties of hydrogen and hydroxyl passivated SiCNWs

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Chinese Physics B 2021年第10期30卷 609-616页

作者： Wan-duo Ma ya-Lin Li Pei Gong ya-Hui Jia Xiao-Yong Fang Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China

Based on the transport theory and the polarization relaxation model,the effects of hydrogen and hydroxyl passivation on the conductivity and dielectric properties of silicon carbide nanowires(SiCNWs)with different sizes are numerically *** results show that the variation trend of conductivity and band gap of passivated SiCNWs are opposite to the scenario of the size effect of bare *** the influencing factors of conductivity,the carrier concentration plays a leading *** the dielectric properties,the bare SiCNWs have a strong dielectric response in the blue light region,while passivated SiCNWs show a more obvious dielectric response in the far ultraviolet-light *** particular,hydroxyl passivation produces a strong dielectric relaxation in the microwave band,indicating that hydroxyl passivated SiCNWs have a wide range of applications in electromagnetic absorption and shielding.

关键词： silicon carbide nanowires passivation conductance properties dielectric relaxation