关于素环平方封闭的李理想的两个结果

Let R be a 2-torsion free prime ring, d1 a nonzero derivation, -γ a generalized derivation associated with a nonzero derivation d2, U a square closed Lie ideal of R. In the present paper,we prove that if [di^2（u）, u] ∈ Z（R） or γ acts as a homomorphism （or an antihomomorphism） on U, then U Z（R）.     

Sharp upper bounds on the second largest eigenvalues of connected graphs

Let ${\lambda }_2$ be the second largest eigenvalue of a graph. Powers (1988) [4] gave some upper bounds of ${\lambda }_2$ for general graphs and bipartite graphs, respectively. Considering that these bounds are not always attainable for connected graphs, we present sharp upper bounds of ${\lambda }_2$ for connected graphs and connected bipartite graphs in this paper. Moreover, the extremal graphs are completely characterized.     

Synthesis,Structure and Properties of a New Lead(Ⅱ) Complex of 1,3-Benzenedicarboxylic Acid, 1,10-Phenanthroline and Its Thermal Decomposition to PbO Micro-crystal Particles

The self-assembly of 1,10-phenanthroline(phen) and 1,3-benzenedicarboxylic acid(H2bdc) with Pb(NO3)2 under solvothermal conditions in N,N-dimethylacetamide(DMA) gives rise to a one-dimensional chain coordination polymer, [Pb(phen)(bdc)](1), which was characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction. This complex crystallizes in triclinic, space group P1 with a = 7.5595(6), b = 9.8199(8), c = 13.1663(11) , α = 69.7590(10), β = 80.6000(10), γ = 71.3180(10)o, Z = 2, C20H12N2O4Pb, Mr = 551.51, Dc = 2.112 g/cm3, F(000) = 520 and μ = 9.757 mm-1. The final R = 0.0304 and wR = 0.0763 for 3427 observed reflections with I 2σ(I) and R = 0.0365 and wR = 0.0894 for all data. The structure contains one crystallographic unique Pb(Ⅱ) atom, one phen molecule chelating with a Pb(Ⅱ) atom, and one bdc2- anion, acting as a bidentate bridging ligand linking the Pb(Ⅱ) atoms to form a one-dimensional structure. The two-dimensional layer and three-dimensional stacking structures are formed by C–H···O hydrogen bonding interactions. The thermal stable and fluorescent properties of 1 were investigated. PbO micro-crystal particles are produced by calcination of powder sample of complex 1. The obtained PbO is characterized and observed by XRD and SEM analyses.     

Synthesis, Structure and Properties of a Two-dimensional Samarium(Ⅲ) Complex of 1,3-Benzenedicarboxylic Acid and 1,10-Phenanthrolin

The title complex Sm2(bdc)3(phen)2n (1, H2bdc = 1,3-benzenedicarboxylic acid, phen = 1,10-phenanthrolin), a new samarium(Ⅲ) complex based on ligand H2 bdc and 1,10-phenanthrolin, has been hydrothermally synthesized and characterized by elemental analysis, FT-IR, and single-crystal X-ray diffraction. The crystal structure reveals that the Sm(1) centre adopts an eight-coordinated distorted square anti-prism coordination geometry, while the Sm(2) centre adopts a nine-coordinated distorted monocapped square prism coordination geometry. The ligand bdc 2-takes two different connecting modes and links the Sm(Ⅲ) centers to give rise to a 2D network structure. Further, 2D layers of 1 are connected together to form a 3D structure through C-H···O hydrogen bonding interactions. The luminescent property and thermal stability of complex 1 are studied. 1 belongs to the triclinic system, space group P1 with a = 10.7367(5), b = 14.3750(7), c = 13.7505(3), α = 92.8840(10), β = 104.4010(10), γ = 98.1400(10)o, Z = 2, V = 2143.44(18)3 , Mr = 1153.44, Dc = 1.787 g/cm3 , F(000) = 1128, μ = 2.784 mm-1 , the final R = 0.0279 and wR = 0.0720 for 8226 observed reflections with Ⅰ > 2σ(Ⅰ).     

基于1，4，5，8-萘四羧酸原位合成的钡配合物的结构、对芳香胺的检测及其作为纳米BaCO3的前驱体

以1,4,5,8-萘四羧酸为原料,在溶剂热条件下原位反应合成得到一个具有3D拓扑结构的发光钡基金属有机骨架(MOF):[Ba(dna)(H₂O)₂]n(1,H₂dna=1,8-萘二甲酸酐-4,5-二羧酸),并通过单晶X射线衍射、元素分析、热重分析和粉末X射线衍射技术对其进行表征。结构分析表明,1包含一个π共轭基团和酸酐基团的有机配体dna^2-,荧光和紫外研究表明其能灵敏地检测溶液中的芳香胺,可能是MOF结构中配体的酸酐基团和氨基之间的反应驱动的,这大大提高了荧光发射强度,并达到裸眼可见的颜色变化。此外,以配合物1为前驱体在中等温度下直接煅烧制得了单一晶型的纳米BaCO₃颗粒。     

Ga2O3-NiO复合氧化物的溶胶-凝胶法制备和气敏性能

用溶胶-凝胶法制备了Ga2O3-NiO复合金属氧化物气敏材料,对其相组成、电导和气敏性能作了研究.结果表明:镍镓物质的量比n(Ni2＋) : n(Ga3＋)=0.7～0.9:2、800 ℃下热处理4 h,得到纯相尖晶石型复合金属氧化物NiGa2O4.缺陷GaNi×的反应(GaNi×→GaNi’＋h●),使NiGa2O4呈p型半导体. n(Ni2＋) : n(Ga3＋)=1:2凝胶粉在800 ℃下热处理4 h,所得纳米微粉制作的元件在313 ℃工作温度下对C2H5OH有较高灵敏度和良好的选择性.