类锂体系(Z=21—30)基态1s22s电离能和相对论项能的理论计算

使用全实加关联方法和里兹(Ritz)变分方法计算了类锂体系(Z=21—30)基态1s²2s的非相对论能量和波函数；包括动能修正、电子-电子接触项、轨道-轨道相互作用项以及Darwin项的相对论修正和质量极化项由全实加关联波函数的一阶微扰给出，量子电动力学修正QED(quantum electronic dynamic)由有效核电荷方法和类氢公式计算；给出了中等核电荷的高电离类锂体系基态的电离能、相对论效应的项能(term energy)，并将计算结果与实验数据进行了比较，表明FCPC 关键词： 类锂体系 全实加关联 电离能 项能     

Synthesis of 3-Aryl-1,3,5-pentanetricarboxylic acid trialkylesters <Emphasis Type="Italic">via</Emphasis> a Tandem Addition-Rearrangement-Addition Reaction

Summary.  In the presence of anhydrous potassium carbonate as base, triethylbenzylammonium chloride as phase transfer catalyst, and dimethylformamide as solvent, 4-nitrophenylsulfonylacetate was treated with alkyl acrylate at 70°C to afford the unexpected 3-aryl-1,3,5-pentanetricarboxylic acid trialkylesters via a tandem addition-rearrangement-addition reaction. A possible mechanism was suggested. Corresponding author. E-mail: scao@263.net Received September 2, 2002; accepted September 13, 2002     

一种新型芳香二胺桥联β-环糊精对染料的分子识别

以单-(6-对甲苯磺酰基)-β-环糊精和3,3′-亚甲基联苯胺为原料, 合成了一种新型刚性结构的芳香二胺桥联环糊精, 3,3′-亚甲基联苯胺桥联(6-氨基-6-脱氧-β-环糊精)2. 并用荧光光谱和紫外光谱技术分别测定了在25 ℃时, pH为7.20的磷酸缓冲溶液中β-环糊精(1)和新型桥联环糊精(2)与几种染料分子, 如吖定红(AR)、中性红(NR)、2-对甲苯胺基-6-萘磺酸钠(TNS)、1-苯胺基-8-萘磺酸铵(ANS)、罗丹明B(RhB)和亮绿(BG)形成超分子配合物的稳定常数KS. 化学计量比表明, 桥联环糊精2与客体形成了1∶1的超分子配合物, 其对客体的键合能力和分子选择性远远强于母体?茁-环糊精, 如桥联环糊精2对BG的键合能力可以达到母体环糊精的22.2倍. 从主-客体间的尺寸匹配关系和多重识别机理等方面探讨了桥联环糊精对客体分子的协同键合作用.     

Synthesis,crystal structure and magnetic properties of triaquahexakis(μ2-betaine)(μ3-oxo)triiron(III) perchlorate heptahydrate

The synthesis and characterization of the oxo-centered carboxylato-bridged trinuclear iron(III) complex, triaquahexakis(₂-betaine)(₃-oxo)triiron(III) perchlorate heptahydrate are described. X-ray crystallography shows that the Fe^III atom in the complex has a slightly distorted octahedral geometry, coordinated by four oxygen atoms from different betaine ligands [Fe—;O = 2.009(3) 2.034(3) Å], one aqua ligand [Fe—O = 2.028(4) and 2.031(3) Å] and the central ₃-oxo atom [Fe—O = 1.917(2) and 1.917(3) Å]. The central oxygen is ideally coplanar with the plane of the three metal atoms. Magnetic susceptibility data (4–320 K) show the presence of an antiferromagnetic exchange interaction with a coupling constant of J = –20.2 cm^–1.     

Anthraquinones from the roots of Prismatomeris tetrandra

Three new anthraquinones, 1-hydroxy-2,3-dimethoxy-7-methyl-9,10-anthraquinone, 1,3-dihydroxy-5,6-dimethoxy-2-methyl-9,10-anthraquinone, and 3-hydroxy-1,5,6-trimethoxy-2-methyl-9,10-anthraquinone, along with five known anthraquinones were isolated from the roots of Prismatomeris tetrandra. Their structures were determined on the basis of spectroscopic data.     

热动力学时间变量法——简单级数化学反应

在热动力学理论基础上提出了一种新的热动力学研究法--时间变量法.该法无须将反应进行到底,只需知道一张热谱图上的3个时间点t,t时刻峰高△和t前峰面积a,就可用计算机数值方法求算反应的速率常数.应用该法研究了一级反应、等浓度二级反应、不等浓度二级反应、三级反应和1.5级反应的热动力学.     

简易电沉积法制备CoFe-P催化剂用于高效析氧反应

开发低成本、高活性且稳定的非贵金属催化剂是实现大规模电解水制氢的关键所在。在此,我们通过简便、合理的电沉积法在泡沫镍(NF)上构建了一种具备超薄二维纳米片形貌的高度非晶相Co1Fe1-P薄膜用于高效催化析氧反应(OER)。在1.0mol·L^-1 KOH溶液中,所制备的Co1Fe1-P/NF催化剂在电流密度为10和100 mA·cm^-2处的过电位分别为274.4和329.5 mV,Tafel斜率仅为 45.3 mV·dec^-1,可以媲美商业 RuO₂催化剂。此外,Co1Fe1-P/NF 催化剂在 10 mA·cm^-2的 100 h 计时电压法测试和1 000次循环伏安法测试中均表现出卓越的催化稳定性。Co1Fe1-P/NF催化剂优秀的催化活性归因于其独特的形貌、高度非晶相结构提供的低能垒、优化的电子结构以及钴磷化物和铁磷化物的强协同效应。     

Theoretical calculation of the triple differential cross sections of the 2p orbital of argon in a coplanar highly asymmetric（e,2e） reaction

The triple differential cross sections of the 2p electron of argon in a coplanar highly asymmetric geometry have been calculated with the modified distorted wave Born approximation (DWBA) and the target Hartree－Fock approximation methods. The damping polarization of the semi-classical short-range potentials and the M_ee factor are included in the distorting potentials of the modified DWBA. Theoretical results are compared with a recent experiment. The dynamic mechanism of inner shell ionization in a coplanar highly asymmetric geometry (e, 2e) reaction are also discussed.     

Effects of Spatial Noncommutativity on Energy Spectrum of a Trapped Bose-Einstein Condensate

In noncommutative space, we examine the problem of a noninteracting and harmonically trapped Bose- Einstein condensate, and derive a simple analytic expression for the effect of spatial noncommutatlvity on energy spectrum of the condensate, it indicates that the ground-state energy incorporating the spatial noncommutativity is reduced to a lower level, which depends upon the noncommutativity parameter 8. The gap between the noncommutative space and commutative one for the ground-state level of the condensate should be a signal of spatial noncommutativity.     

氢化与氟化五边形石墨烯双层电子性能调控的第一性原理研究

基于密度泛函理论的第一性原理计算方法,我们研究了氢化、氟化及氢氟化五边形石墨烯双层对其电子性能的调控.计算结果表明,氢化和氟化的五边形石墨烯双层可分别在价带顶及导带底形成局域的电子态而显著降低带隙.基于这一特性,我们进一步研究氢氟化的五边形石墨烯双层结构对电子能带的影响,并且发现通过调控氢氟化覆盖度能够有效调节带隙,进而实现五边形石墨烯双层从半导体到金属态的转变.