The title complex [Fe（L-trp）2（HL-trp）2]n （L-trp = L-tryptohan or 2-amino-3-（1H -indol-3-yl）-propanoic acid） has been formed by a hydrothermal method involving hexaaquacobaltous perchlorate and L-tryptophan. Th...The title complex [Fe（L-trp）2（HL-trp）2]n （L-trp = L-tryptohan or 2-amino-3-（1H -indol-3-yl）-propanoic acid） has been formed by a hydrothermal method involving hexaaquacobaltous perchlorate and L-tryptophan. The product was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 19.828（3）, b = 5.4233（14）, c = 9.2796（16） A, β= 97.691（2）°, V = 988.9（3） A3, Z = 2, Mr = 462.29, Dx = 1.553 g/cm3, F（000） = 480,/a = 0.802 mm^-1, the final R = 0.0399 and wR = 0.0930 for 1738 observed reflections with I 〉 2σ（/）. The structural analysis shows that the complex assumes a two-dimensional double chain plane structure.展开更多
The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degr...The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degree of Al atoms is obviously higher than that of Fe atoms,and the ordering of Al atoms precedes their clustering,while the case of Fe atoms is opposite.The α site is mainly occupied by Ni atoms,while the β site is occupied in common by Al,Fe and Ni atoms.At order-disorder interphase boundary,the ordering degree of Al atoms is higher than that of Fe atoms,and at the β site,the Fe atomic site occupation probabilities vary from high to low during ordering;the Al atomic site occupation probabilities are similar to those of Fe atoms,but their values are much higher than those of Fe atoms;Ni atoms are opposite to both of them.Meanwhile,during the ordering transformation,γ' phase is always a complex Ni3(AlFeNi)single-phase,and it is precipitated by the non-classical nucleation and growth style.Finally,in the alloy system,the volume of γ' ordered phase is less than that of γ phase,and the volume ratio of order to disorder is about 77%.展开更多
By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L...By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.展开更多
基金Supported by the foundation of the Science Committee of Jiangsu Province (No. BK2005045)the Key Marine Biotechnology Laboratory of Jiangsu Province (No. 2005HS010)
文摘The title complex [Fe（L-trp）2（HL-trp）2]n （L-trp = L-tryptohan or 2-amino-3-（1H -indol-3-yl）-propanoic acid） has been formed by a hydrothermal method involving hexaaquacobaltous perchlorate and L-tryptophan. The product was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 19.828（3）, b = 5.4233（14）, c = 9.2796（16） A, β= 97.691（2）°, V = 988.9（3） A3, Z = 2, Mr = 462.29, Dx = 1.553 g/cm3, F（000） = 480,/a = 0.802 mm^-1, the final R = 0.0399 and wR = 0.0930 for 1738 observed reflections with I 〉 2σ（/）. The structural analysis shows that the complex assumes a two-dimensional double chain plane structure.
基金Project(50671084)supported by the National Natural Science Foundation of ChinaProject(Z200714)supported by Graduate Starting Seed Fund of Northwestern Polythechnical University,China
文摘The process of γ(fcc)→γ(fcc)+γ'(L12)phase transformation was simulated by using microscopic phase-field method for the low supersaturation NiAl9Fe6 alloy.It is found that in the γ' phase,the ordering degree of Al atoms is obviously higher than that of Fe atoms,and the ordering of Al atoms precedes their clustering,while the case of Fe atoms is opposite.The α site is mainly occupied by Ni atoms,while the β site is occupied in common by Al,Fe and Ni atoms.At order-disorder interphase boundary,the ordering degree of Al atoms is higher than that of Fe atoms,and at the β site,the Fe atomic site occupation probabilities vary from high to low during ordering;the Al atomic site occupation probabilities are similar to those of Fe atoms,but their values are much higher than those of Fe atoms;Ni atoms are opposite to both of them.Meanwhile,during the ordering transformation,γ' phase is always a complex Ni3(AlFeNi)single-phase,and it is precipitated by the non-classical nucleation and growth style.Finally,in the alloy system,the volume of γ' ordered phase is less than that of γ phase,and the volume ratio of order to disorder is about 77%.
文摘By use of self-consistent field Xα scattered-wave (SCF-Xα-SW) method, the electronic structure was calculated for four models of Ti4Al14X (X=Al, Fe, Ni and Cu) clusters. The Ti4Al14X cluster was developed based on L12 Al3Ti-base intermetallic compound. The results are presented using the density of states (DOS) and one-electron properties, such as relative binding tendency between the atom and the model cluster, and hybrid bonding tendency between the alloying element and the host atoms. By comparing the four models of Ti4Al14X cluster, the effect of the Fe, Ni or Cu atom on the physical properties of Al3Ti-based L12 intermetallic compounds is analyzed. The results indicate that the addition of the Fe, Ni or Cu atom intensifies the relative binding tendency between Ti atom and Ti4Al14X cluster. It was found that the Fermi level (EF) lies in a maximum in the DOS for Ti4Al14Al cluster; on the contrary, the EF comes near a minimum tn the DOS for Ti4Al14X (X=Fe, Ni and Cu) cluster. Thus the L12 crystal structure for binary Al3Ti alloy is unstable, and the addition of the Fe, Ni or Cu atom to Al3Ti is benefical to stabilize L12 crystal structure. The calculation also shows that the Fe, Ni or Cu atom strengthens the hybrid bonding tendency between the central atom and the host atoms for Ti4Al14X cluster and thereby may lead to the constriction of the lattice of Al3Ti-base intermetallic compounds.
