一维梯状配合物{[Cu2(4,4''-bpy)3(p-Ab)2(H2O)2]·(NO3)2·4H2O}n的晶体结构

合成了一维分子梯状配合物{[Cu2(4,4'-bpy)3(p-Ab)2(H2O)2]·(NO3) 2·4H2O}n(4,4'-bpy=4,4'-联吡啶,p-Ab-=对氨基苯甲酸根离子),该配合物晶体属单斜晶系,P2(1)/c空间群,晶胞参数:a=1.110 7(5) nm,b=1.550 4(3) nm,c=1.450 9(3) nm,β=104.81(3)°,V=2.415 5(12) nm3,Z=2.铜离子周围有3个氧原子和3个氮原子与之配位,其中2个氧原子由对氨基苯甲酸的螯合氧原子提供,另一个氧原子由配位水提供,3个氮原子分别由三个4,4'-联吡啶提供.这六个原子在铜离子周围形成一个畸变的八面体配位环境.配体对氨基苯甲酸只有一种配位形式--双齿螯合,第二配体4,4'-联吡啶的两个氮原子均参与配位,将配合物组装成一维分子梯结构.     

反应耦合现象和现代热力学分类系统

现代热力学的一个重要推论———反应耦合现象 ,长期来没有得到很好的论证 ,还引发了长期的争论 ,严重地阻碍着热力学在现代科学中的应用和热力学自身的发展。本文以激活低压金刚石气相生长为例 ,为反应耦合现象提供了定量化的证明 ,相应地建立了包含非平衡相图新领域的现代热力学完整分类系统     

Studies on the Binding Mode of Pinacyanol Chloride to Nucleic Acids

The interaction of pinacyanol chloride(PC) with nucleic acids has been investigated by a series of experiments.Extensive hypochromism,appreciable peak shifts,isosbestic points and new peaks of the product of binding to nucleic acids in the spectra were observed.They showed that the interaction between PC and nucleic acids occurred.The results from absorption spectra of DNA,DNA melting,electrophoresis and fluorescence polarization studies have indicated that PC binds to DNA in nonintercalative way.Consistent with the nonintercalation,the studies of fluorescence titration and absorption titration specified that the binding of PC to nucleic acids occurred by an outside stacking binding,in which nucleic acids served for acting templates,The fact that the new absorption peaks of bound PC at ca,485nm are just close to the absorption bands of Haggregate of PC at high concentrations without DNA further supports the outside stacking binding mode,In addition,other evidence indicated that the interaction between PC and nucleic acids is not purely electrostatic.     

氟钽酸钾中碳存在形式的探讨

本文从氟钽酸钾（Ｋ２ＴａＦ６）的生产工艺论述了有机物存在于Ｄ２ＴａＦ６的可能性。通过Ｋ２ＴａＦ６低温通氧燃烧前后测定碳的结果比较，以及Ｘ射线能谱仪表面分析结果，证实了碳的来源是残留的有机萃取剂。     

环形聚苯乙烯的稀溶液性质——Ⅱ. 第二维利系数

第二维利系数(A_2)是表征高分子链段间和高分子溶剂分子间相互作用的参数。对于环形高分子的第二维利系数,最早Casassa曾做过计算。利用“双接触”模型,Casassa计算了环形高分子的第二维利系数(A_(2r))为A_(2r)=(N_αβN~2/2M~2)[1-C_z O(z~2)]式中M为聚合物的分子量,N_α为Avogadro常数,N为高分子链段数,β为表征链段对排斥体积的二元集团积分,Z为排斥体积参数。式中系数C对环形或线形分子数值不同。     

高校扩招环境下提升大学物理实验教学的一些对策

高等教育大规模发展,高等教育在短短几年内迅速地进入了大众化时代普通高校本专科招生人数由1998年的108万人飙升到2011年的675万招生数量是过去的六倍多。大量学子享用高等教育扩招的盛宴的同时,扩招后的高等教育质量问题最引人注目。众所周知,大学物理实验课是全国高等院校中惟一单独开设的一门实验课程,是理工科学生进人大学后最先接触的对其进行科学实验基本训练的一门基础必修课。而实验教学对于提高学生的综合     

带有分布时滞和非线性发生率的媒介-宿主传染病模型全局稳定性(英文)

本文分析一类带有分布时滞和非线性发生率的媒介-宿主传染病动力学性质,得到模型基本再生数R0,发现系统中平衡态的全局动力学性质能够由基本再生数来完全确定:即,如果R01,无病平衡态是全局渐近稳定的;如果R01,则系统存在唯一地方病平衡态,并且该平衡态是全局渐近稳定的.     

Alternating-current losses in two-layer superconducting cables consisting of second-generation superconductors coated by U-shaped ferromagnetic materials

Alternating-current losses in a two-layer superconducting cable, each layer being composed of 15 closely-spaced rectangular wires made up of second-generation superconductors when the ends of wires are coated by either a non-magnetic or strong ferromagnetic material having a U profile is numerically investigated. Computations are carried out through the finite-element method. The alternating-current losses do not increase significantly if the relative permeability of the coating is increased three orders of magnitude, provided that the current amplitude is less than half of the critical current in a superconducting wire. However, the losses are much higher for ferromagnetic coating if the amplitude of the applied current oscillating at 50 Hz is close to the critical current. The ferromagnetic coating is seen to accumulate the magnetic field lines normally on its surfaces, while the field lines are parallel to the long axes of the wires, leading to more significant flux penetration in the coated regions. This facilitates a uniform low-loss current flow in the uncoated regions of the wires. In contrast, coating with a non-magnetic material gives rise to a considerably smaller current flow in the uncoated regions, whereas the low-loss flow is maintained in the coated regions. Moreover, the current flows in opposite directions in the coated and uncoated regions, where the direction in each region is converse for the two materials.     

珠心算优秀选手中女性占多数问题之探讨

上网搜索发现,目前参加人数较多、规模较大的国内外计算类比赛通常有三种:一是计算比赛,即任何计算工具、方法均可使用的比赛;二是珠算比赛;三是珠心算比赛。尽管后两种看起来不同,实际是通用的,即采用珠算或珠心算均可。无论哪一种比赛形式,优胜者都是运用珠心算的选手,而这些优秀选手中女性占了大多数。这是为什么呢?让我们共同来探讨这一问题。     

有心圆锥曲线上四点的两种不同形式类西摩松线

根据文[1],直线l及其平行线被有心圆锥曲线L截得弦的中点和曲线L的中心都在同一直线l’上,直线l’叫有心圆锥曲线L关于直线l的共轭直径.有心圆锥曲线中类西摩松线的内容是:在中心为O的圆锥曲线L上任取三点A、B、C,曲线L关于直线BC、CA、AB的共轭直径分别为OD、OE、OF,在曲线L上取异于A、B、C的一点