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Antioxidative Responses and metal Accumulation in Invasive Plant Species Growing on mine Tailings in zanjan, Iran

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Pedosphere 2011年第6期21卷 802-812页

作者： m.m.A.BOOJAR z.TAVAKKOlI Department of Biology Tarbiat Moalem University

Tailings of a Pb and zn mine as a metal-contaminated area （zone 1） with two pioneer plant species, Peganum harmala and zygophyllum fabago, were investigated and compared with a non-contaminated area （zone 2） in the vicinity. Total concentrations of Pb, zn, and Cu in the soil of zone 1 were 1 416, 2 217, and 426 mg kg-1, respectively, and all exceeded their ranges in the normal soils. The soil pH was in the neutral range and most of the physical and chemical characteristics of the soils from both zones were almost similar. The species z. fabago accumulated higher Cu and zn in its aerial part and roots than the normal plants. On the other hand, their concentrations did not reach the criteria that the species could be considered as a metal hyperaccumulator. The species P. harmala did not absorb metals in its roots; accordingly, the accumulation factor values of these metals were lower than 1. The contents of chlorophyll, biomass, malondialdehyde, and dityrosine in these two species did not vary significantly between the two zones studied. In zone 1, leaf vacuoles of z. fabago stored 35.6% and 43.2% of the total leaf Cu and zn, respectively. However, in this species, the levels of phytochelatins （PCs） and glutathione （GSH） and antioxidant enzyme activities were significantly higher in zone 1 than in zone 2. In conclusion, metal exclusion in P. harmala and metal accumulation in z. fabago were the basic strategies in the two studied pioneer species growing on the metal-contaminated zone. In response to metal stress, elevation in antioxidant enzyme activities, increases in the PCs and GSH levels in the aerial parts, and metal storage within vacuoles counteracted each other in the invasion mechanism of z. ]abago.

关键词： accumulation factor antioxidant enzymes glutathione metal stress phytochelatins

Computation of the Fractal Pattern in manganese Dendrites

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Chinese Physics letters 2005年第8期22卷 2112-2115页

作者： z.merdan m.Bayirli DepartmentofPhysics GaziosmanpasaUniversityTokatTurkey

The images of manganese flowers (clusters) on the surface of the natural magnesium silicate substance are scanned and the pictures of them are transferred to computer atmosphere. By using these scanning parameters, the exponents of density correlation function and fractal dimension values are calculated. For all different groups between the least and the most dense in the samples, the correlation function exponents may range from 0.141 to 0.178 and the fractal dimension values may vary between 1.61 and 1.88. In addition, the manganese flowers are divided into seven different groups according to their smallest- and largest-density features. The formation of the natural manganese clusters (flowers, dendrites) on the surface of the magnesium silicate substance can be defined by using the deposition, diffusion and aggregation model.

关键词： DDA CO Pattern

Finite Element Prediction of the Thermal Conductivity of GNP/Al Composites

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Acta metallurgica Sinica(English letters) 2022年第5期35卷 825-838页

作者： X.S.Yang l.zhou K.Y.liu z.Y.liu Q.z.Wang B.l.Xiao z.Y.ma School of Electromechanical and Automotive Engineering Yantai UniversityYantai264005China Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

A 3 D multi-scale finite element model was developed to predict the effective thermal conductivity of graphene nanoplatelet(GNP)/Al *** factors influencing the effective thermal conductivity of the GNP/Al composites were investigated,including the orientation,shape,aspect ratio,configuration and volume fraction of *** results show that GNPs shape has a little influence on the thermal conductivity of GNP/Al composites,and composites with elliptic GNPs have the highest thermal *** addition,with increasing the aspect ratio of GNPs,the thermal conductivity of GNP/Al composites increases and finally tends to be *** GNPs configuration strongly influences the thermal conductivity of GNP/Al composites,and the thermal conductivity of the composites with layered GNPs is the highest among the five *** effective thermal conductivity is sensitive to volume fraction of ***,when the volume fraction of layered GNPs reaches 1.54%,the thermal conductivity of GNP/Al composites is as high as 400 W/m *** findings of this study could provide a good theoretical basis for designing high thermal conductivity GNP/Al composites.

关键词： multi-scale finite element model Thermal conductivity GNP/Al composites Shape Aspect ratio Configuration

High-Speed Friction Stir Welding of T6-Treated B4Cp/6061Al Composite

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Acta metallurgica Sinica(English letters) 2020年第1期33卷 67-74页

作者： Y.z.li Y.N.zan Q.z.Wang B.l.Xiao z.Y.ma Key laboratory of Nuclear materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China Shenyang National laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China University of Science and Technology of China Shenyang 110016China

T6-treated 20 wt% B4 Cp/6061 Al sheets were joined under welding speeds of 400–1200 mm/min by friction stir welding(FSW) with a threaded cermet pin. The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min, but larger plunge depth was required at the welding speeds of 800 and 1200 mm/min to eliminate the tunnel defect. In the nugget zone(Nz) of the joints, the B4 C particles were broken up and uniformly redistributed. The Nz exhibited lower hardness than the base metal(Bm), and the hardness value almost did not change with increasing welding speed, attributable to the dissolution of precipitates. Compared with the Bm, the joints showed lower tensile strength. As the welding speed increased from 400 to 800 mm/min, the joint efficiencies were nearly the same and up to ~ 73%. When the welding speed increased up to 1200 mm/min, the tensile strength significantly decreased, due to the occurrence of kissing bond defect at the bottom of the Nz. With increasing welding speed, the fracture location of the joints transferred gradually from the heat-affected zone to the Nz due to the kissing bond defects.

关键词： metal-matrix composites microstructures mechanical properties Friction stir welding High-speed welding

Development and application of functional gene arrays for microbial community analysis

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中国有色金属学会会刊：英文版 2008年第6期18卷 1319-1327页

作者： z. l. HE J. D. VAN NOSTRAND l.Y. WU J. z. zHOU Institute for Environmental Genomics Department of Botany and Microbiology University of Oklahoma Norman OK 73019 USA

功能的基因标记能关于功能的基因差异和微生物引起的社区的潜在的活动提供重要信息。尽管 microarray 技术成功地被使用了为纯文化学习基因表示，简单、人工的微生物引起的社区，改编如此的一种技术分析复杂微生物引起的社区仍然以设计... 详细信息

功能的基因标记能关于功能的基因差异和微生物引起的社区的潜在的活动提供重要信息。尽管 microarray 技术成功地被使用了为纯文化学习基因表示，简单、人工的微生物引起的社区，改编如此的一种技术分析复杂微生物引起的社区仍然以设计，样品准备，和数据分析提出很多挑战。这个工作集中于功能的基因数组(FGA ) 的开发和应用程序为微生物引起的社区研究指向关键功能的基因标记。一些与 FGA 有关明确地给问题调音，例如 oligonucleotide 探查设计， nucleic 酸抽取和纯化，数据分析，特性，敏感，和量的能力详细被讨论。最近的研究证明了 FGA 能从许多自然环境关于微生物引起的社区提供特定、敏感、潜在地量的信息并且控制生态系统。这种技术被期望革命化微生物引起的社区的分析，并且连接微生物引起的结构到生态系统工作。

关键词：微数列应用函数基因标记微生物种群

A prediction model for the effective thermal conductivity of nanofluids considering agglomeration and the radial distribution function of nanoparticles

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Acta mechanica Sinica 2018年第3期34卷 507-514页

作者： z.m.z.eng B.Wang School of Physics Sun Yat-Sen UniversityGuangzhou 510275China Instimt Franco-Chinois de l'Energie Nucleaire Sun Yat-Sen UniversityZhuhai 519000China

Conventional heat transfer fluids usually have low thermal conductivity, limiting their efficiency in many applications. many experiments have shown that adding nanosize solid particles to conventional fluids can greatly enhance their thermal conductivity. To explain this anomalous phenomenon, many theoretical investigations have been conducted in recent years. Some of this research has indicated that the particle agglomeration effect that commonly occurs in nanofluids should play an important role in such enhancement of the thermal conductivity, while some have shown that the enhancement of the effective thermal conductivity might be accounted for by the structure of nanofluids, which can be described using the radial distribution function of particles. However, theoretical predictions from these studies are not in very good agreement with experimental results. This paper proposes a prediction model for the effective thermal conductivity of nanofluids, considering both the agglomeration effect and the radial distribution function of nanoparticles. The resulting theoretical predictions for several sets of nanofluids are highly consistent with experimental data.

关键词： Nanofluid Thermal conductivity modeling Agglomeration Radial distribution function

Water Sorption Behaviors of Novel Biohybrid Hydrogels as Effective Sorbents in Water-Solvent Binary mixtures

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Journal of Encapsulation and Adsorption Sciences 2020年第3期10卷 43-70页

作者： Erdener Karadağ Belgin Yel Semiha Kundakcı Ömer barış Üzüm Aydın Adnan menderes University Fen-Edebiyat Faculty Chemistry Department Ayd&#305n Turkey

Novel sorbent hydrogels containing acrylamide/sodium vinylsulfonate, carboxymethyl cellulose and zeolite were synthesized with free radical solution polymerization by using ammonium persulfate/N,N,N’,N’-tetramethylethyle-nediamine as redox initiating pair in presence of poly(ethylene glycol) diacrylate as crosslinker. It was to investigate the water uptake properties of series of the novel hydrogels, the semi IPNs and the hybrid/biohybrid composite hydrogel sorbents synthesized in this study. Water uptake studies were performed in water and in water-solvent (acetone, methanol and tetrahydrofuran) binary mixtures at 25°C, gravimetrically. Some swelling and diffusion parameters were calculated and discussed. It has been seen that the lower equilibrium swelling factor values in all solvent compositions in comparison with the equilibrium swelling factor values in water.

关键词： Acrylamide/Sodium Vinylsulfonate Biohybrid Hydrogel Swelling Carboxymethyl Cellulose zeolite Water-Solvent Binary mixtures

Preparation of an adsorptive membrane of polyvinylidene fluoride incorporated functionalized boron nitride nanosheets for arsenic removal

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Chinese Journal of Chemical Engineering 2024年第12期76卷 49-63页

作者： S.Selambakkannu N.l.Ishak N.m.Fauzi N.Ismail z.A.Karim Radiation Processing Technology Division Malaysia Nuclear AgencyBangiKajang 43000Malaysia Advanced membrane Technology Research Centre(AmTEC) Faculty of Chemical and Energy EngineeringUniversiti Teknologi MalaysiaSkudaiJohor81310Malaysia

Incorporating nanomaterials into membranes will enhance wastewater treatment efficiency with their unique characteristics,such as higher permeability,thermal stability,surface roughness,hydrophilicity,and fouling *** this study,the surface-modified boron nitride with phosphoric acid 2-hydroxyethyl methacrylate ester(PA/BN)was grafted with polyethylene glycol(PEG)via conventional *** PEG grafted PA/BN(PEG-g-PA/BN)melt blended with polyvinylidene fluoride(PVDF)resin by using an internal mixer at different mass percentages 100%PVDF(PVDF),3%PEG-g-PA/BN+97%PVDF(97:3 BN),5%PEG-g-PA/BN+95%PVDF(95:5 BN),7%PEG-g-PA/BN+93%PVDF(93:7 BN),and 7%PEG-g-PA/BNNS+93%PVDF(93:7 BNNS).Phase inversion technique was used to cast the blended mixture into a thin *** prepared membranes were analyzed with different characterization techniques to determine chemical composition,crystallinity,morphology,and thermal *** prepared composite membrane was evaluated in terms of water permeability,anti-fouling resistance,and solute rejection efficiency with deionized water,bovine serum albumin,and arsenic solution as *** membranes show high water flux and *** water flux and porosity of the blends decrease as the percentage of PEG-g-PA/BN ***,the highest removal capacity for arsenic was observed at 93:7 *** adsorption of arsenic ions takes place via complexation with PA/BN in the PVDF *** was confirmed with field emission scanning electron microscopyeenergy-dispersive X-ray analysis and X-ray photoelectron spectroscopy analyses.

关键词： Adsorption Ultrafiltration Preparation membranes

Predicting the response of continuous RC deep beams under varying levels of differential settlement

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 686-700页

作者： m.z.NASER R.A.HAWIlEH Glenn Department of Civil Engineering Clemson UniversityClemsonSC 29634USA Department of Civil Engineering American University of SharjahSharjahUnited Arab Emirates materials Science and Engineering Research Institute American University of SharjahSharjahUnited Arab Emirates

This paper investigates the effect of differential support settlement on shear strength and behavior of continuous reinforced concrete(RC)deep beams.A total of twenty three-dimensional nonlinear finite element models were developed taking into account various constitutive laws for concrete material in compression(crushing)and tension(cracking),steel plasticity(i.e.,yielding and strain hardening),bond-slip at the concrete and steel reinforcement interface as well as unique behavior of spring-like support *** models are first validated by comparing numerical predictions in terms of load-deflection response,crack propagation,reaction distribution,and failure mode against that of measured experimental data reported in *** the developed models were successfully validated,a parametric study was designed and *** parametric study examined number of critical parameters such as ratio and spacing of the longitudinal and vertical reinforcement,compressive and tensile strength of concrete,as well as degree(stiffness)and location of support stiffness to induce varying levels of differential *** study also aims at presenting a numerical approach using finite element simulation,supplemented with coherent assumptions,such that engineers,practitioners,and researchers can carry out simple,but yet effective and realistic analysis of RC structural members undergoing differential settlements due to variety of load actions.

关键词： concrete continuous beams deep beams finite element modeling support settlement