A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,el...A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,elemental analysis,IR,and magnetic properties.X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB-ligands.The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ)and im4-py radical.The magnetic property is explained by the magnetic and structure exchange mechanism.CCDC:976028.展开更多
Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal s...Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal sources and N,N-dimethylformamide was employed as a solvent as well as a reductant to produce Cu(Ⅰ) complexes.(ⅱ) An iodide-containing compound was utilized as a ligand and iodide source to prepare complexes.An in situ metalligand reaction occurred and an iodide-bridged copper complex was generated.(ⅲ) A series of aldehydes were added to the reaction systems to induce in situ metal-ligand reactions between the aldehydes and the imidazo[1,5-a]pyridine derivatives,producing polydentate ligand scaffolds.Eight complexes were prepared and characterized.The catalytic activities of these complexes toward the ketalization of ketones by ethylene glycol were investigated.With the exception of complex4,the remaining seven complexes all showed high catalytic activity.The lower activity of 4 may be due to the larger radius of bridging iodide ions and the shorter Cu(Ⅰ)…Cu(Ⅰ) distance.CCDC:2357696,1·2CH_(2)Cl_(2);2357697,2;2018292,3;2092192,4;2092190,5;2155557,6;2406155,7;2406156,8·EtOH.展开更多
横波可控震源振动器平板作为页岩气勘探中的关键部件,其疲劳寿命直接影响可控震源的使用寿命和勘探精度。然而,传统的振动器平板疲劳寿命优化方法未考虑平板与平板齿间焊接残余应力的影响,导致平板结构在抗疲劳优化设计方面效果不佳。为...横波可控震源振动器平板作为页岩气勘探中的关键部件,其疲劳寿命直接影响可控震源的使用寿命和勘探精度。然而,传统的振动器平板疲劳寿命优化方法未考虑平板与平板齿间焊接残余应力的影响,导致平板结构在抗疲劳优化设计方面效果不佳。为此,使用局部灵敏度法对平板疲劳寿命进行敏感性分析,确定了焊接残余应力为影响疲劳寿命的关键因素。随后,建立了平板的各向最大焊接残余应力与焊接速度和焊接层间温度之间的数学模型,并以各向最大焊接残余应力为约束,以疲劳寿命为优化目标,建立相应的优化模型。最后,利用NSGA-Ⅱ(nondominated sorting genetic algorithm-Ⅱ,非支配排序遗传算法-Ⅱ)获取Pareto解集,并结合熵权法和TOPSIS(technique for order preference by similarity to ideal solution,逼近理想解排序)法确定最佳优化方案:焊接速度为10.23 mm/s,焊接层间温度为105℃。结果表明,优化后平板的疲劳寿命为10.23年,相比优化前提高了17.72%。研究结果可为横波可控震源振动器平板的疲劳寿命优化提供科学有效的理论方法和工程指导。展开更多
文摘A new cobalt(Ⅱ)-radical complex:[Co(im4-py)_(2)(PNB)_(2)](im4-py=2-(4'-pyridyl)-4,4,5,5-tetramethylimidazole-1-oxyl,HPNB=p-nitrobenzoic acid)has been synthesized and characterized by X-ray diffraction analysis,elemental analysis,IR,and magnetic properties.X-ray diffraction analysis shows that the complex exists as mononuclear molecules and Co(Ⅱ)ion is four-coordinated with two radicals and two PNB-ligands.The magnetic susceptibility study indicates the complex exhibits weak ferromagnetic interactions between cobalt(Ⅱ)and im4-py radical.The magnetic property is explained by the magnetic and structure exchange mechanism.CCDC:976028.
文摘Three efficient methods for the synthesis of a series of Cu(Ⅱ) and Cu(Ⅰ) complexes based on imidazo[1,5-a]pyridine derivatives were developed.These methods include the following:(ⅰ)Cu(Ⅱ) salts were used as metal sources and N,N-dimethylformamide was employed as a solvent as well as a reductant to produce Cu(Ⅰ) complexes.(ⅱ) An iodide-containing compound was utilized as a ligand and iodide source to prepare complexes.An in situ metalligand reaction occurred and an iodide-bridged copper complex was generated.(ⅲ) A series of aldehydes were added to the reaction systems to induce in situ metal-ligand reactions between the aldehydes and the imidazo[1,5-a]pyridine derivatives,producing polydentate ligand scaffolds.Eight complexes were prepared and characterized.The catalytic activities of these complexes toward the ketalization of ketones by ethylene glycol were investigated.With the exception of complex4,the remaining seven complexes all showed high catalytic activity.The lower activity of 4 may be due to the larger radius of bridging iodide ions and the shorter Cu(Ⅰ)…Cu(Ⅰ) distance.CCDC:2357696,1·2CH_(2)Cl_(2);2357697,2;2018292,3;2092192,4;2092190,5;2155557,6;2406155,7;2406156,8·EtOH.
文摘横波可控震源振动器平板作为页岩气勘探中的关键部件,其疲劳寿命直接影响可控震源的使用寿命和勘探精度。然而,传统的振动器平板疲劳寿命优化方法未考虑平板与平板齿间焊接残余应力的影响,导致平板结构在抗疲劳优化设计方面效果不佳。为此,使用局部灵敏度法对平板疲劳寿命进行敏感性分析,确定了焊接残余应力为影响疲劳寿命的关键因素。随后,建立了平板的各向最大焊接残余应力与焊接速度和焊接层间温度之间的数学模型,并以各向最大焊接残余应力为约束,以疲劳寿命为优化目标,建立相应的优化模型。最后,利用NSGA-Ⅱ(nondominated sorting genetic algorithm-Ⅱ,非支配排序遗传算法-Ⅱ)获取Pareto解集,并结合熵权法和TOPSIS(technique for order preference by similarity to ideal solution,逼近理想解排序)法确定最佳优化方案:焊接速度为10.23 mm/s,焊接层间温度为105℃。结果表明,优化后平板的疲劳寿命为10.23年,相比优化前提高了17.72%。研究结果可为横波可控震源振动器平板的疲劳寿命优化提供科学有效的理论方法和工程指导。
