C2(×)Cn量子系统的最大纠缠混合态

讨论了C2(×)Cn量子系统的最大纠缠混合态,得到了Negativity纠缠度下的最大纠缠混合态的解析结果,并计算了该态在非满秩情形下的量子相对熵纠缠度.     

Integrable semiclassical deformations of general algebraic curves and associated conservation laws

Based on the Lenard relations, we completely classify integrable deformations of general algebraic curves. We construct the general solution of the Lenard relation from the invariance condition with respect to an element of the Galois group of the curve. We give some examples and also some associated conservation laws. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 151, No. 3, pp. 458–469, June, 2007.     

Crossing of shears bands in196Pb

High-spin states in¹⁹⁶Pb have been populated using the reaction¹⁷⁰Er(³⁰Si,4n). The previously observed shears bands in this nucleus have been extended and some of their transitions have been reordered. They now form regular bands with band crossings. One of the bands splits into two pathways at high spin.     

On Subspaces and Quotients of Banach Spaces C(K, X)

 We study the relation of to the subspaces and quotients of Banach spaces of continuous vector-valued functions , where K is an arbitrary dispersed compact set. More precisely, we prove that every infinite dimensional closed subspace of totally incomparable to X contains a copy of complemented in . This is a natural continuation of results of Cembranos-Freniche and Lotz-Peck-Porta. We also improve our result when K is homeomorphic to an interval of ordinals. Next we show that complemented subspaces (resp., quotients) of which contain no copy of are isomorphic to complemented subspaces (resp., quotients) of some finite sum of X. As a consequence, we prove that every infinite dimensional quotient of which is quotient incomparable to X, contains a complemented copy of . Finally we present some more geometric properties of spaces. Received 8 November 2000; in revised form 7 December 2001     

Evaluation of the accuracy of the determination of lead isotope ratios in wine by ICP MS using quadrupole, multicollector magnetic sector and time-of-flight analyzers

Different mass analysers [(quadrupole (Q), time-of-flight (TOF) and multicollector (MC) sector-field (SF)] of ions produced in an inductively coupled plasma were evaluated for the determination of lead isotope ratios in wine samples. A population of 20 wines of different origin including two reference wines from the EC Standards, Measurement and Testing Programme with concentrations varying between 7-140 mug Pb l(-1) was investigated. Wines were analyzed directly by Q ICP MS and MC ICP MS. The poor sensitivity of the TOF instrument, further aggravated by matrix signal suppression, did not allow the acquisition of data for wine samples that contained less than 50 mug l(-1) in the direct sample introduction mode. The separation and preconcentration of lead were therefore required. The precision obtained for the (206)Pb/(207)Pb and (208)Pb/(206)Pb were similar and equal to 0.14-2.7% for Q ICP MS, 0.04-0.17% for TOF ICP MS and 0.01-0.12% for MC ICP MS. The precision for (206)Pb/(204)Pb was 0.44-5.29, 0.15-1.7, 0.08-1.6%, respectively. On the level of accuracy, the data from TOF ICP MS and MC ICP MS were in good agreement. The accuracy of Q ICP MS data was judged satisfactory in comparison with the other techniques but their poor precision was a significant obstacle on the way of using these data for the determination of the geographic origin of wine.     

酞侧基聚芳醚砜和聚芳醚酮共混物的高温流变行为

用锥板粘度计测试了酞侧基聚芳醚砜（ＰＥＳ－Ｃ）和酞侧基聚芳醚酮（ＰＥＫ－Ｃ）及其共混物的熔体流变行为．试样的流动活化能分别为１４５、１３３和１１２ＫＪ／ｍｏｌ．共混物的熔体粘度显著低于ＰＥＳ－Ｃ和ＰＥＫ－Ｃ粘度的对数加和值．并证明试样的熔体流动性和加工稳定性都已达到注射成型工艺的要求．     

Aldol condensations over reconstructed Mg-Al hydrotalcites: structure-activity relationships related to the rehydration method

Two different rehydration procedures in the liquid or gas phase have been applied to reconstruct mixed oxides derived from calcined hydrotalcite-like materials to be used as catalysts for aldol condensation reactions. The as-synthesized hydrotalcite, its decomposition product, as well as the reconstructed solids upon rehydration were characterized by XRD, N(2) adsorption, He pycnometry, FTIR, SEM, TEM, (27)Al MAS-NMR and CO(2)-TPD (TPD=temperature-programmed desorption). Compared to the Mg-Al mixed oxide rehydrated in the gas phase (HT-rg), that rehydrated in the liquid phase (HT-rl) exhibits a superior catalytic performance with respect to the aldol condensation of citral with ketones to yield pseudoionones and in the self-aldolization of acetone. The textural properties of HT-rl and HT-rg differ strongly and determine the catalytic behavior. A memory effect led to a higher degree of reconstruction of the lamellar structure when the mixed oxide was rehydrated in the gas phase rather than in the liquid phase, although liquid-phase rehydration under fast stirring produced a surface area that was 26 times greater. This contrasts to typical statements in the literature claiming a higher degree of reconstruction in the presence of large amounts of water in the medium. CO(2)-TPD shows that the number of OH(-) groups and their nature are very similar in HT-rg and HT-rl, and cannot explain the markedly different catalytic behavior. Accordingly, only a small fraction of the available basic sites in the rehydrated samples is active in liquid-phase aldol condensations. Our results support the model in which only basic sites near the edges of the hydrotalcite platelets are partaking in aldol reactions. Based on this, reconstructed materials with small crystallites (produced by exfoliation during mechanical stirring), that is, possessing a high external surface area, are beneficial in the reactions compared to larger crystals with a high degree of intraplatelet porosity.