The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3 C lamellae i n the investigation plane parall...The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3 C lamellae i n the investigation plane parallel to the radial directions of molds was observed to differ from that in the investigation plane perpendicular to the radial directions by transmission electron microscopy. The lattice constants a0 of α-Fe deduced from the XRD patterns of samples prepared using a sand(S)-mold and cut parallel to the radial direction of the mold(S∥) and using a metal(M)-mold and cut parallel to the radial direction(M∥), the corrosion resistance measured using an electrochemical workstation, and the magnetic permeability obtained by vibrating sample magnetometry also indicated the existence of anisotropy in the tested samples. The anisotropic change of corrosion potential(Ecorr), pitting potential(Epit) and magnetic permeability(μ) of the samples was observed to depend on the orientation factor F200 of α-Fe in the measured samples, which is controlled by the distribution of Fe3 C lamellae in the eutectoid structure.展开更多
The crystallization of the (Fe0.78Si_(0.09)B0.13)100-xNix glassy alloys (x=0, 2 and 5) has been investigated by X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Corrosion resistance analyses have b...The crystallization of the (Fe0.78Si_(0.09)B0.13)100-xNix glassy alloys (x=0, 2 and 5) has been investigated by X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Corrosion resistance analyses have been carried out using electrochemical measurements and corrosion products have been analyzed by scanning electron microscopy (SEM). The experimental results show that the addition of Ni can promote the nucleation of α-Fe, retard the decomposition of the metastable borides, and alter the crystallization mode of the present Fe-based glassy alloys. The lattice constant (a0Fe) of α-Fe in the annealed samples shows a decreasing trend with increasing annealing time. The Ni addition can improve the corrosion resistance of the as-quenched Fe-based glassy alloys in H2SO4, NaCl and NaOH solutions. The results indicate that Ni can promote the diffusion of Si atoms during quenching and annealing processes.展开更多
The deterioration of water caused by industrial production is a thorny problem.Solving the problem cogently through innovative coagulationstrategies has been recognized of important practical significance.In this work...The deterioration of water caused by industrial production is a thorny problem.Solving the problem cogently through innovative coagulationstrategies has been recognized of important practical significance.In this work,a simple enhanced coagulation by using ferric chloride(FC)and poly-ferric chloride(PFC)coupled with polyamidine(PA)were tried to remove the toxic organics.The results shown that PA addition could obviously enhance coagulation performances of the iron-based coagulants.The synergic coagulation process and mechanism were studied and discussed in detail based on the coagulation behaviors,flocs properties,removal eficiency and zeta potentials.FC and PFC remove organics mainly through charge neutralization and adsorption-bridging,resulting in a good purification performance.While PA with a higher charge density showed better purification performance due to enhanced charge neutralization.It is worth mentioning that the addition of PA could make the coagulants adapt to a wider pH range,and remove the toxic organics more effectively.That is to say,the practical adaptability of the coagulant was enhanced.This work thus provides a simple strategy to effectively purify wastewater and further improve the water safety.展开更多
In this study,a new and facile route was employed for synthesis of polyamidine with abundant cations and attractive five-membered ringlike structural unit.N-vinylformamide and acrylonitrile copolymerized firstly to fo...In this study,a new and facile route was employed for synthesis of polyamidine with abundant cations and attractive five-membered ringlike structural unit.N-vinylformamide and acrylonitrile copolymerized firstly to form intermediates,and the intermediates were processed with hydrochloric acid to produce polyamidine.A series of polymerization conditions(e.g.polymerization time,temperature and dosage of initiator) were optimized through productivity,viscosity and cationic degree as evaluation.SEM analysis illustrated that the amidinization process could reduce the size of spaces between molecular and created compact structure,which would contribute to good flocculation performance and high viscosity.FT-IR,XPS and NMR spectra presented a rather clear structure of polyamidine.34.3%of sludge was sedimentated through the flocculation of polyamidine in the early stages.In contrast,only 6.8%of sludge was sedimentated by polyacrylamide.The moisture content in dehydrated floc could be reduced to 77.7%when 60 mg/L polyamidine was added.These results demonstrated that the polyamidine showed a great potential in the practical application of sludge dewatering.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51171091 and 51471099)the Excellent Youth Project of Natural Science Foundation of Shandong (No. JQ201012)the Major State Basic Research Development Program of China (No. 2012CB825702)
文摘The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3 C lamellae i n the investigation plane parallel to the radial directions of molds was observed to differ from that in the investigation plane perpendicular to the radial directions by transmission electron microscopy. The lattice constants a0 of α-Fe deduced from the XRD patterns of samples prepared using a sand(S)-mold and cut parallel to the radial direction of the mold(S∥) and using a metal(M)-mold and cut parallel to the radial direction(M∥), the corrosion resistance measured using an electrochemical workstation, and the magnetic permeability obtained by vibrating sample magnetometry also indicated the existence of anisotropy in the tested samples. The anisotropic change of corrosion potential(Ecorr), pitting potential(Epit) and magnetic permeability(μ) of the samples was observed to depend on the orientation factor F200 of α-Fe in the measured samples, which is controlled by the distribution of Fe3 C lamellae in the eutectoid structure.
基金the National Natural Science Foundation of China (Nos.50871061 and 51171091)the Shandong Excellent Youth Award Foundation (No.2008BS04020)+1 种基金the Excellent Youth Project of Natural Science Foundation of Shandong (JQ201012)the Open Project of Key Lab of Magnetism, Magnetic Materials in Lanzhou University (LZUMMM 2010008) for financial supports
文摘The crystallization of the (Fe0.78Si_(0.09)B0.13)100-xNix glassy alloys (x=0, 2 and 5) has been investigated by X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Corrosion resistance analyses have been carried out using electrochemical measurements and corrosion products have been analyzed by scanning electron microscopy (SEM). The experimental results show that the addition of Ni can promote the nucleation of α-Fe, retard the decomposition of the metastable borides, and alter the crystallization mode of the present Fe-based glassy alloys. The lattice constant (a0Fe) of α-Fe in the annealed samples shows a decreasing trend with increasing annealing time. The Ni addition can improve the corrosion resistance of the as-quenched Fe-based glassy alloys in H2SO4, NaCl and NaOH solutions. The results indicate that Ni can promote the diffusion of Si atoms during quenching and annealing processes.
基金financially supported by Taishan Scholar Foundation,China(No.ts201511003)Major Technological Innovation Engineering Project of Shandong Province,China(No.2020CXGC011204).
文摘The deterioration of water caused by industrial production is a thorny problem.Solving the problem cogently through innovative coagulationstrategies has been recognized of important practical significance.In this work,a simple enhanced coagulation by using ferric chloride(FC)and poly-ferric chloride(PFC)coupled with polyamidine(PA)were tried to remove the toxic organics.The results shown that PA addition could obviously enhance coagulation performances of the iron-based coagulants.The synergic coagulation process and mechanism were studied and discussed in detail based on the coagulation behaviors,flocs properties,removal eficiency and zeta potentials.FC and PFC remove organics mainly through charge neutralization and adsorption-bridging,resulting in a good purification performance.While PA with a higher charge density showed better purification performance due to enhanced charge neutralization.It is worth mentioning that the addition of PA could make the coagulants adapt to a wider pH range,and remove the toxic organics more effectively.That is to say,the practical adaptability of the coagulant was enhanced.This work thus provides a simple strategy to effectively purify wastewater and further improve the water safety.
基金supported by the Tai Shan Scholar Foundation(No.ts201511003)
文摘In this study,a new and facile route was employed for synthesis of polyamidine with abundant cations and attractive five-membered ringlike structural unit.N-vinylformamide and acrylonitrile copolymerized firstly to form intermediates,and the intermediates were processed with hydrochloric acid to produce polyamidine.A series of polymerization conditions(e.g.polymerization time,temperature and dosage of initiator) were optimized through productivity,viscosity and cationic degree as evaluation.SEM analysis illustrated that the amidinization process could reduce the size of spaces between molecular and created compact structure,which would contribute to good flocculation performance and high viscosity.FT-IR,XPS and NMR spectra presented a rather clear structure of polyamidine.34.3%of sludge was sedimentated through the flocculation of polyamidine in the early stages.In contrast,only 6.8%of sludge was sedimentated by polyacrylamide.The moisture content in dehydrated floc could be reduced to 77.7%when 60 mg/L polyamidine was added.These results demonstrated that the polyamidine showed a great potential in the practical application of sludge dewatering.