谈谈量子力学中的状态叠加原理

以对话的形式,介绍并评论了布洛欣采夫、狄拉克以及朗道和栗弗席茨关于状态叠加原理的不同表述.     

A useful reparameterization for second‐order autoregressive processes

In time series analysis, autoregressive (a.r.) models are often fitted successfully to data, and such models are usually among the first to be taught. It is therefore important to understand why such models are useful in practice. An alternative parameterization for second order a.r. models, which assists understanding and interpretation, is discussed. The models are most plausible if certain restrictions are placed on the autoregressive parameters, which in turn lead to restrictions on the autocorrelation coefficients. Fitting the reparameterized model is straightforward, and the reparameterization may be extended, less usefully, to higher order a.r. models. The second‐order model is fitted to some meteorological data.     

Efficient Photoinduced Electron Transfer in a Rigid U-Shaped Tetrad Bearing Terminal Porphyrin and Viologen Units

Apparently solvent-mediated and not through-bond photoinduced electron transfer (ET) takes place from the porphyrin (P) unit to the methylviologen (MV²⁺) unit in the rigid U-shaped molecules 1 (i.e., k_TS^ET>k_TB^ET; TS=through-solvent, TB=through-bond). The ratio of the rates of charge separation to charge recombination is greater than 1400:1.     

Conversion of (-)-3-dehydroshikimic acid into derivatives of the (+)-enantiomer

(-)-3-DHS (1), a compound available in large quantity through "engineering" of the shikimic acid pathway, has been converted over eight steps into the methyl ester, ent-2, of the (+)-enantiomer. Methyl (+)-shikimate (15) and its C-3 epimer (ent-5) have also been prepared by related means.     

Proton and anion control of framework complexity in copper(II) complex structures derived from 2-(hydroxymethyl)pyridine

Three copper(II) complexes derived from 2-(hydroxymethyl)pyridine (LH) have been synthesised and a comparative X-ray investigation of their respective crystal structures undertaken. In the absence of added base, LH reacts with copper(II) chloride or nitrate to yield the five-coordinate [Cu(LH)₂Cl]Cl and six-coordinate [Cu(LH)₂(NO₃)₂] species. In the chloro complex the coordination geometry is distorted trigonal bipyramidal, with the pyridyl nitrogens occupying the axial position and two hydroxyl oxygens from the bidentate ligands together with a chloro group occupying the equatorial sites. The structure of the nitrate species, published previously, has been reinvestigated at low temperature in order to specify the weak interactions in the crystal; it contains two molecules of bidentate LH bound trans in the equatorial plane while monodentate nitrato ligands occupy the axial sites. In each of these complexes the hydroxyl protons act as hydrogen bond donors, interacting with the non-coordinated chloride anion in [Cu(LH)₂Cl]Cl and the coordinated nitrato groups in [Cu(LH)₂(NO₃)₂] to form bridged, hydrogen-bonded, copper(II)-organic arrays in each case; offset face-to-face π-stacking in the latter produces a two dimensional structure. Further weak CH?Cl, CH?O interactions stabilise both arrangements. The X-ray structure of the complex [Cu(L)₂] · 4H₂O containing the deprotonated ligand is also described. The presence of the latter results in the above hydrogen bonding arrangements being ‘switched off’ and instead a new two-dimensional network involving bridging tetrameric water clusters hydrogen bound to adjacent ligand hydroxo groups to give extended sheets is generated; offset face-to-face π-stacking occurs between sheets to yield a three dimensional array.     

医药类专业物理课程教学存在的问题及对策

根据对国内69所普通高等院校医药类专业（本科）物理课程教学现状调查的结果,分析了在我国高等教育进入“大众化教育”的形势下,医药类专业物理课程教学中存在的4个急需解决的问题,指出了医药类专业物理课程教学改革的方向,并介绍了我们所做的一些工作。