Effects of the processing methods on the mechanical properties of treated bagasse fibre reinforced epoxy composite were evaluated. The composite materials were processed by employing hand lay-up and compression mouldi...Effects of the processing methods on the mechanical properties of treated bagasse fibre reinforced epoxy composite were evaluated. The composite materials were processed by employing hand lay-up and compression moulding methods and fibres were treated with NaOH solution. The composite samples were subjected to tensile, flexural and impact tests. Based on the findings, compression moulding method produced better mechanical properties compared to the composites manufactured by hand lay-up method. The results showed that the tensile strength and Young’s modulus of the samples produced by compression moulding method increased by 77 percent and 47 percent respectively (at optimal fibre loading) compared to those produced by the hand lay-up method. The results also showed noticeable improvements in the impact strength of the material produced by compression moulding method, with impact strength of 11.5 kJ/m2 against the samples produced by hand lay-up method, with impact strength of 7 kJ/m2.展开更多
The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusio...The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusion coeffients of Li^+,K^+,F^- and Cl^- have been calculated. The results are in agreement with the experimental values.The regularities of the distribution of ions and mieroscopic holes are discussed based on the results of computerized simulation.展开更多
The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field e...The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field emission scanning electron microscopy and fluorospectrophotometer. The results indicate that the Ce3+ and Tb3+ enteres the host lattice because the XRD patterns of alkaline earth phosphate show no impurity phase, the SEM shows the spherical particles with an average size about 1 μm. The emission and excitation spectra are similar to rare earth phosphate. Concentration quenching of the Sr3(PO4)2∶Ce, Tb emission intensity was not observed even when the Tb3+ increases to 0.05, while the maximum emission intensity appears when x=0.04 in M3-3x(PO4)2∶2xCe, xTb(M=Ca, Ba) emission spectrum.展开更多
The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of ...The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of the atom of alkali metal was completely transferred to 5T_(1u) orbital of C_(60).The stabilization energy of the system results mainly from the electrostatic interaction between polarized C_(60) and alkali metal atom.展开更多
针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造...针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。展开更多
文摘Effects of the processing methods on the mechanical properties of treated bagasse fibre reinforced epoxy composite were evaluated. The composite materials were processed by employing hand lay-up and compression moulding methods and fibres were treated with NaOH solution. The composite samples were subjected to tensile, flexural and impact tests. Based on the findings, compression moulding method produced better mechanical properties compared to the composites manufactured by hand lay-up method. The results showed that the tensile strength and Young’s modulus of the samples produced by compression moulding method increased by 77 percent and 47 percent respectively (at optimal fibre loading) compared to those produced by the hand lay-up method. The results also showed noticeable improvements in the impact strength of the material produced by compression moulding method, with impact strength of 11.5 kJ/m2 against the samples produced by hand lay-up method, with impact strength of 7 kJ/m2.
文摘The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusion coeffients of Li^+,K^+,F^- and Cl^- have been calculated. The results are in agreement with the experimental values.The regularities of the distribution of ions and mieroscopic holes are discussed based on the results of computerized simulation.
基金Heilongjiang Province Education Office (10553013)the Open Laboratory of HUST
文摘The M3-3x(PO4)2∶2xCe, xTb(M=Mg, Ca, Sr, Ba) phosphors were prepared by coprecipitation in this paper. Their phase structures, morphologies and luminescent properties were investigated by X-ray diffractometer, field emission scanning electron microscopy and fluorospectrophotometer. The results indicate that the Ce3+ and Tb3+ enteres the host lattice because the XRD patterns of alkaline earth phosphate show no impurity phase, the SEM shows the spherical particles with an average size about 1 μm. The emission and excitation spectra are similar to rare earth phosphate. Concentration quenching of the Sr3(PO4)2∶Ce, Tb emission intensity was not observed even when the Tb3+ increases to 0.05, while the maximum emission intensity appears when x=0.04 in M3-3x(PO4)2∶2xCe, xTb(M=Ca, Ba) emission spectrum.
基金Supported in part by the National Natural Science Foundation of China.
文摘The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of the atom of alkali metal was completely transferred to 5T_(1u) orbital of C_(60).The stabilization energy of the system results mainly from the electrostatic interaction between polarized C_(60) and alkali metal atom.
文摘针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。
