Correlated oscillations in the excitation functions of deep-inelastic collisions: evidence for nuclear pulsars?

Excitation functions for the strongly dissipative collision ¹⁹ F(E _lab = 135–140 MeV)+⁸⁹ Y with an energy step of 250 keV in the lab. system have been measured. The data are consistent with previous measurements and exhibit oscillations, which are interpreted as an indication of quantum chaotic phenomena in dissipative heavy-ion collisions. The Fourier component of the energy autocorrelation of the total projectile-like angle-integrated dissipative yield has been calculated and is found to have a pulsing behaviour with a time interval between sequential pulses equal to the period of the coherent nuclear rotation. This provides another possibility of experimentally detecting quantum chaos in dissipative heavy-ion collisions.     

Coexistence of non-registered monolayer and bilayer solid films: Statistical mechanics

A statistical mechanical theory is developed for low temperature solid monolayer and bilayer films of inert gases which are not in registry with the adsorbing substrate. The free energy is evaluated in terms of harmonic lattice vibrations of the solids, which is a quasiharmonic approximation. The lattice constant discontinuity in the transition under compression from the monolayer to the bilayer is found to be small, in accord with experiments on the adsorption of xenon and of krypton on silver and of argon on basal plane graphite. The calculations use realistic models for adatom interactions and substrate holding potentials in these three systems. At the bilayer formation, the lattice constant is still distinctly larger than that of the corresponding bulk solid under its vapor pressure. Thermodynamic functions of the phases at monolayer and bilayer coexistence are evaluated: the spreading pressure and the bilayer latent heat of adsorption are nearly constant along the coexistence curve for temperatures of 1 to 35 K. The calculated difference between the latent heats of adsorption of the monolayer and the bilayer is in good agreement with experimental data for the xenon/silver system, but it is smaller than the experimental difference for the krypton/silver and argon/graphite systems.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定铁镍软磁合金中的镍

研究了电感耦合等离子体原子发射光谱法(ICP-AES)快速测定铁镍软磁合金中的镍含量,确定了最佳测定条件,以波长221.647nm作为镍的分析线,对溶解酸和酸浓度的影响进行探讨,选择钇作为内标元素。分析试样得到结果的相对标准偏差RSD小于0.91%(n=6),方法回收率为99.8%～100.1%(n=6),分析结果与丁二酮肟分光光度法相一致。电感耦合等离子体原子发射光谱法比传统的化学法准确、快速,已成功用于生产中。     

The major product ion of S‐adenosyl‐L‐methionine arises from a neighbouring group reaction

Previous studies have shown that low‐energy collision‐induced dissociation (CID) of the important sulfonium ion metabolite S‐adenosyl‐L‐methionine (AdoMet, m/z 399) yields five main product ions: an ion at m/z 250 arising from methionine loss; ions at m/z 102 and 298, which arise via cleavage of the γ C? S bond of methionine; and ions at m/z 136 and 264, which arise via loss of protonated and neutral adenine, respectively. These metabolomics studies have, however, either totally ignored the mechanisms that govern the formation of the major product ion at m/z 250 (Gellekink H, van Oppenraaij‐Emmerzaal D, van Rooij A, Struys EA, den Heijer M, Blom HJ. Clin. Chem. 2005; 51: 1487), or have proposed an oxonium ion structure that must arise via a rearrangement involving a 1,2 hydride shift (Cataldi TRI, Bianco G, Abate S, Mattia D. Rapid Commun. Mass Spectrom. 2009; 23: 3465). Here DFT calculations on a model system are used to examine potential mechanisms for the formation of the major product ion of AdoMet. These calculations suggest that a neighbouring group mechanism is preferred over a 1,2 hydride shift mechanism. Copyright © 2010 John Wiley & Sons, Ltd.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定铁镍软磁合金中的镍

研究了电感耦合等离子体原子发射光谱法(ICP-AES)快速测定铁镍软磁合金中的镍含量,确定了最佳测定条件,以波长221.647nm作为镍的分析线,对溶解酸和酸浓度的影响进行探讨,选择钇作为内标元素。分析试样得到结果的相对标准偏差RSD小于0.91%(n=6),方法回收率为99.8%~100.1%(n=6),分析结果与丁二酮肟分光光度法相一致。电感耦合等离子体原子发射光谱法比传统的化学法准确、快速,已成功用于生产中。     

矿物材料在超级电容器电极中应用的研究进展

矿物资源是人类社会发展和国民经济建设的重要物质基础,是人类社会生产和发展的动力,矿物资源的合理利用在人类的每一次进步飞跃中起着重要意义。目前而言,在能源社会的背景下,人类对矿物资源的利用也在越来越深入。同时,在能源储存方面有着很广阔的应用前景。本文通过晶系分类法综述了各类天然矿物材料在超级电容器上的研究进展,目的是为以后对天然矿物材料在电化学领域进行深入研究奠定一个基础。对存在的问题进行了分析,为下一步的研究提出了建议。     

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