Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been investigated.Quantum molecular descripto...Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been investigated.Quantum molecular descriptors of noncovalent configurations were studied.It was specified that binding of capecitabine onto γ-Fe2O3 nanoparticles is thermodynamically suitable.Hardness and the gap of energy between LUMO and HOMO of capecitabine are higher than the noncovalent configurations,showing the reactivity of capecitabine increases in the presence of γ-Fe2O3 nanoparticles.Capecitabine can bond to γ-Fe2O3 nanoparticles through OH（k1 mechanism）,NH（k2 mechanism）,CO（k3 mechanism） and F（k4 mechanism） groups.The activation energies,activation enthalpies and activation Gibbs free energies of these reactions were calculated.It was specified that the k1 and k2 mechanisms are under thermodynamic control and k3 and k4 under kinetic control.These results could be generalized to other similar drugs.展开更多
Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-...Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.展开更多
采用沉淀法制备磁性γ-Fe2O3脱硝催化剂,通过瞬态动力学方法考察NH3、O2气体浓度对催化剂选择性催化还原(SCR)脱硝率的影响,在消除内外扩散阻力基础上应用稳态动力学研究方法构建SCR脱硝本征反应动力学模型。实验结果表明:NH3能快速在...采用沉淀法制备磁性γ-Fe2O3脱硝催化剂,通过瞬态动力学方法考察NH3、O2气体浓度对催化剂选择性催化还原(SCR)脱硝率的影响,在消除内外扩散阻力基础上应用稳态动力学研究方法构建SCR脱硝本征反应动力学模型。实验结果表明:NH3能快速在催化剂表面活性位上吸附活化;NO的吸附及其活性过渡中间体的形成在SCR反应中起控制作用;O2浓度小于1%时,其浓度的提高促进了磁性γ-Fe2O3催化剂SCR反应进行;在试验条件下,磁性γ-Fe2O3催化剂的NO、NH3、O2的反应级数分别为0.41、0、0.27,但当O2浓度>1%时,其反应级数为0,研究得到磁性γ-Fe2O3催化剂SCR表观反应活化能为28.77 k J/mol。展开更多
文摘Using density functional theory,noncovalent interactions and four mechanisms of covalent functionalization of capecitabine anticancer drug onto γ-Fe2O3 nanoparticles have been investigated.Quantum molecular descriptors of noncovalent configurations were studied.It was specified that binding of capecitabine onto γ-Fe2O3 nanoparticles is thermodynamically suitable.Hardness and the gap of energy between LUMO and HOMO of capecitabine are higher than the noncovalent configurations,showing the reactivity of capecitabine increases in the presence of γ-Fe2O3 nanoparticles.Capecitabine can bond to γ-Fe2O3 nanoparticles through OH（k1 mechanism）,NH（k2 mechanism）,CO（k3 mechanism） and F（k4 mechanism） groups.The activation energies,activation enthalpies and activation Gibbs free energies of these reactions were calculated.It was specified that the k1 and k2 mechanisms are under thermodynamic control and k3 and k4 under kinetic control.These results could be generalized to other similar drugs.
文摘Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased.
文摘采用沉淀法制备磁性γ-Fe2O3脱硝催化剂,通过瞬态动力学方法考察NH3、O2气体浓度对催化剂选择性催化还原(SCR)脱硝率的影响,在消除内外扩散阻力基础上应用稳态动力学研究方法构建SCR脱硝本征反应动力学模型。实验结果表明:NH3能快速在催化剂表面活性位上吸附活化;NO的吸附及其活性过渡中间体的形成在SCR反应中起控制作用;O2浓度小于1%时,其浓度的提高促进了磁性γ-Fe2O3催化剂SCR反应进行;在试验条件下,磁性γ-Fe2O3催化剂的NO、NH3、O2的反应级数分别为0.41、0、0.27,但当O2浓度>1%时,其反应级数为0,研究得到磁性γ-Fe2O3催化剂SCR表观反应活化能为28.77 k J/mol。
