电荷-宇称(CP)对称性破坏和夸克-轻子味物理——写在CP破坏发现和夸克理论提出40周年之际

简要地介绍了与电荷-宇称（CP）对称性破坏和夸克-轻子味物理有关的一些重要进展.从1964年发现CP破坏和提出夸克理论至今,这个领域就一直成为粒子物理研究的前沿领域,已研究和发展了整整40年,取得了许多辉煌的成就.在这篇文章中,着重评述了目前仍然热门的几个主要的研究方向：直接CP 破坏的理论研究和实验验证,CP破坏机制和新的CP破坏源,中微子物理和新的味物理,夸克味物理和有效量子场理论,标准模型中味物理参数的预言和超对称大统一理论.同时对我国有关研究组在这些前沿方向做出的重要贡献作了重点简述.可以看出,在CP破坏和味物理这个重要前沿领域,仍然存在着许多未解之谜,使得粒子物理在21世纪既面临着巨大的挑战,又有着不断发展的机遇.     

Development and validation of a high performance liquid chromatography quantification method of levo‐tetrahydropalmatine and its metabolites in plasma and brain tissues: application to a pharmacokinetic study

Levo ‐tetrahydropalmatine (l‐ THP) is an alkaloid isolated from Chinese medicinal herbs of the Corydalis and Stephania genera. It has been used in China for more than 40 years mainly as an analgesic with sedative/hypnotic effects. Despite its extensive use, its metabolism has not been quantitatively studied, nor there a sensitive reliable bioanalytical method for its quantification simultaneously with its metabolites. As such, the objective of this study was to develop and validate a sensitive and selective HPLC method for simultaneous quantification of l‐ THP and its desmethyl metabolites l‐ corydalmine (l‐ CD) and l‐ corypalmine (l‐ CP) in rat plasma and brain tissues. Rat plasma and brain samples were processed by liquid–liquid extraction using ethyl acetate. Chromatographic separation was achieved on a reversed‐phase Symmetry® C₁₈ column (4.6 × 150 mm, 5 μm) at 25°C. The mobile phase consisted of acetonitrile–methanol–10 mm ammonium phosphate (pH 3) (10:30:60, v /v) and was used at a flow rate of 0.8 mL/min. The column eluent was monitored at excitation and emission wavelengths of 230 and 315 nm, respectively. The calibration curves were linear over the concentration range of 1–10,000 ng/mL. The intra‐ and interday reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. The validated HPLC method was successfully applied to analyze samples from a pharmacokinetic study of l‐ THP in rats. Taken together, the developed method can be applied for bioanalysis of l‐ THP and its metabolites in rodents and potentially can be transferred for bioanalysis of human samples.     

Solid‐state CP/MAS 13C NMR studies on conformational polymorphism in sertraline hydrochloride,an antidepressant drug

The C(2) isotropic chemical shift values in solid‐state CP/MAS ¹³C NMR spectra of conformational polymorphs Form I (δ 28.5) and III (δ 22.9) of (1S,4S)‐sertraline HCl ( 1 ) were correlated with a γ‐gauche effect resulting from the respective 162.6° antiperiplanar and 68.8° (+)‐synclinal C(2)? C(1)? N? CH₃ torsion angles as measured by X‐ray crystallography. The similarity of the solution‐state C(2) chemical shifts in CD₂Cl₂ (δ 22.8) and DMSO‐d₆ (δ 23.4) with that for Form III (and other polymorphs having C(2)? C(1)? N? CH₃ (+)‐synclinal angles) strongly suggests that a conformational bias about the C(1)? N bond exists for 1 in both solvents. This conclusion is supported by density functional theory B3LYP/6‐31G(d)‐calculated relative energies of C(1)? N rotameric models: (kcal) 0.00 [73.8 °C(2)? C(1)? N? CH₃ torsion angle], 0.88 (168.7°), and 2.40 (?63.4°). A Boltzmann distribution of these conformations at 25 °C is estimated to be respectively (%) 80.3, 18.3, and 1.4. Copyright © 2002 John Wiley & Sons, Ltd.     

Isomorphism of bis(diethyldithiocarbamato)zinc(II) adduct with pyridine, [Zn(Py)(EDtc)2]: hysteresis in the reaction of the adduct formation

The structure of the polycrystalline adduct bis(diethyldithiocarbamato)-pyridine zinc(II) depends on the pathway of physico-chemical conditions during the preparation procedure, as was revealed by solid state ¹⁵N CP/MAS spectroscopy in good correlation with known single crystal X-ray diffraction structures of this adduct. Two isomorphs of the adduct, namely α-[Zn(Py)(S₂CNEt₂)₂] and β-[Zn(Py)(S₂CNEt₂)₂], are the two molecules in the asymmetric unit of a single crystal (or polycrystalline) sample that can be obtained by recrystallization from toluene of the equimolar solution of the initial diethyldithiocarbamate zinc(II) complex and pyridine. The third isomorph, γ-[Zn(Py)(S₂CNEt₂)₂], can be obtained by recrystallization from pure pyridine of the diethyldithiocarbamate zinc(II) complex, or by its equimolar absorption of pyridine, or by desorption of pyridine from the clathrated adduct, [Zn(Py)(S₂CNEt₂)₂]·Py. Finally, the γ-[Zn(Py)(S₂CNEt₂)₂] isomorph recrystallizes from the melt into α/β-isomorphs of the adduct.     

Poly(ethylene terephthalate) copolymers containing nitroterephthalic units. II. Crystallization and conformational studies

The effect of incorporating a nitro side group into the phenylene units of poly(ethylene terephthalate) (PET) on the conformation and crystallizability of this polyester was evaluated. Random poly(ethylene terephthalate‐co‐nitroterephthalate) (PETNT) copolymers containing 5, 10, and 15 mol % nitroterephthalic units were investigated with reference to PET. All the examined copolymers were semicrystalline and were found to adopt the triclinic crystal structure of PET, with the nitrated units being excluded from the crystallites. Both the crystallinity and crystallization rate of PETNT largely decreased with the content of nitrated units, and the O? CH₂? CH₂? O trans‐to‐gauche conformational ratio increased with crystallization, attaining comparable values for all the compositions. The conformation and crystallinity of isothermally crystallized PET and PETNT samples could be correlated with the size of the crystallites generated in each case. However, a different crystal perfecting mechanism seemed to operate for PET and for the PETNT copolymers when they were subjected to annealing. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2759–2771, 2002     

蚕丝蛋白的NMR研究——Ⅲ.天蚕茧层固态~(13)C CP—MASNMR研究

本文分别测定了东北天蚕茧和龙(?)天蚕茧各内,中,外三层茧层的固态~(13)CCP-MASNMR波谱,对其谱峰进行了归属,估算了谱峰区主要谱线在该区所占的比例,还计算了各个茧层丝蛋白中无定形状态所占的百分含量。谱图显示了东北天蚕茧层与龙(?)天蚕茧层丝蛋白结构的差异。     

Constraint Programming Based Column Generation for Crew Assignment

Airline crew assignment problems are large-scale optimization problems which can be adequately solved by column generation. The subproblem is typically a so-called constrained shortest path problem and solved by dynamic programming. However, complex airline regulations arising frequently in European airlines cannot be expressed entirely in this framework and limit the use of pure column generation. In this paper, we formulate the subproblem as a constraint satisfaction problem, thus gaining high expressiveness. Each airline regulation is encoded by one or several constraints. An additional constraint which encapsulates a shortest path algorithm for generating columns with negative reduced costs is introduced. This constraint reduces the search space of the subproblem significantly. Resulting domain reductions are propagated to the other constraints which additionally reduces the search space. Numerical results based on data of a large European airline are presented and demonstrate the potential of our approach.     

弱衰变Bd→J/ψKS中的CP破坏与新物理

最近BaBar与Belle国际合作组对弱衰变Bd→J/ψKS 中的CP破坏测量结果似乎暗示有新物理存在于B0d-B0d 混合.为此给出一个模型无关的分析,以说明新物理对标准模型结果的可能修正.特别强调,即使实验证明Bd→J/ψKS 中的CP破坏效应与标准模型的预言相符,仍然有可能存在新物理.