Effect of dead carbon on the C-14 dating of the speleothem

IEECAS SKLLQG

~(12)C与~(209)Bi反应中Au同位素的产额与Q_(gg)的关系；Q_(gg)-Yield Dependence of Au Isotopes in Interaction of 47 MeV/u ~(12)C With ~(209)Bi

用47MeV/u12C离子轰击天然铋靶,通过炮弹和靶核之间的核子转移反应产生Au同位素。使用放射化学方法从大量Bi和复杂反应产物中分离、纯化Au,并制备Au的γ射线测量源。使用HPGe探测器测量放射性Au同位素的γ活性。根据照射结束时Au同位素的活度和其他相关数据,确定每个Au同位素的产生截面。分析发现,缺中子Au同位素的产生截面与Qgg值之间不遵从指数依赖关系,这可用重离子碰撞中的次级过程加以解释。

~(12)C离子束辐照对酵母发酵能力的影响；Improved ethanol fermentation of a yeast mutant by C-12 ion beam irradiation

利用100MeV/u的12C6+离子束辐照酵母Saccharomyces cerevsiea YY,选育出一株高产突变菌株C03A,考察C03A发酵过程中不同温度、pH、糖汁浓度对发酵的影响。通过正交实验确定最佳发酵条件为:糖汁浓度24%、温度35℃、pH5.0。在10L发酵罐实验中,C03A发酵速率相对原始菌株高,36h发酵完全,比原始菌株缩短12h;发酵产酒率达到13.2%(V/V),比原始菌株高1.6%(V/V)。

Influence of metal particle size on the hydrogenation of maleic anhydride over Pd/C catalysts in scCO(2)

Hydrogenation of maleic anhydride (MAH) with Pd/C catalysts in supercritical carbon dioxide (scCO(2)) was investigated. The selectivity for gamma-butyrolactone (GBL) reached 97.3% in scCO(2) at 100% conversion of MAH, which was notably higher than that of 77.4% obtained in organic solvent of ethylene glycol dimethyl ether (EGDME). The particle size of Pd exhibited large influence on the reaction rate and selectivity of GBL. Higher selectivity of GBL was obtained with Pd/C catalyst of smaller Pd particle size, and the rate of GBL selectivity increase as a function of CO2 pressure was found to be significantly correlated with Pd particle size.

Microstructure, thermal stability and mechanical properties of the novel (W1-xAlx)C-Co (x=0.2, 0.33, 0.4, 0.5) cemented carbide

Bulk novel cemented carbides (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) are prepared by mechanical alloying and hot-pressing sintering. Hot-pressing (HP) is used to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have good mechanical properties compared with WC-Co. The density and operating cost of the novel material is much lower than a WC-Co system. The material is easy to process and the processing leads to nano-scaled, rounded, particles in the bulk material. The hardness of (W1-xAlx)C-10.1 vol% Co (x = 0.2, 0.33, 0.4, 0.5) hard material is 20.37, 21.16, 21.59 and 22.16 GPa, and the bending strength is 1257, 1238, 1211 and 1293 MPa, with the aluminum content varying from 20% to 50%. The relationship between the microstructure and the mechanical properties of the novel hard alloy is also discussed.

Surface-enhanced resonance Raman spectroscopic study of yeast iso-1-cytochrome c and its mutant

The structural stability and redox properties of yeast iso-1-cytochrome c and its mutant, F82H, were studied by surface-enhanced resonance Raman scattering (SERRS) spectroscopy. Phenylalanine, which exists at the position-82 in yeast iso-1-cytochrome c, is replaced by histidine in the mutant. The SERRS spectra of the proteins on the bare silver electrodes indicate that the mutant possesses a more stable global structure with regard to the adsorption-induced conformational alteration. The redox potential of the mutant negatively shifts by about 400 mV, relative to that of yeast iso-1-cytochrome c. This is ascribed to axial ligand switching and higher solvent accessibility of the heme iron in the mutant during the redox reactions.

Methods to study the ionic conductivity of polymeric electrolytes using a.c. impedance spectroscopy

Composite polymeric electrolytes of PEO-LiClO4-Al2O3 and PEO-LiClO4-EC were prepared and the ionic conductivity by a.c. impedance was calculated using four different methods, and three kinds of representations of a.c. impedance spectra were adopted. The first is based on the Nyquist impedance plot of the imaginary part (Z") versus the real part (Z') of the complex impedance. The second and the third correspond to the plots of imaginary impedance Z" as a function of frequency (f), and the absolute value (\Z\) and phase angle (theta) as a function of f, respectively. It was found that the values of the ionic conductivity calculated using the three representations of a.c. impedance spectra are basically identical.

The Celtic Inscriptions of Britain: Phonology and Chronology, c. 400-1200, Publications of the Philological Society, 37

Sims-Williams, P. (2002). The Celtic Inscriptions of Britain: Phonology and Chronology, c. 400-1200. Publications of the Philological Society, 37. Oxford: Blackwell Publishing. RAE2008

The contribution of warlordism to the disintegration of the western Roman army (c. AD 395-480)

My thesis investigates the dynamics behind the changing nature of the leadership of the western Roman army in the fifth century through the concept of ‘warlordism’. I carried this out by analyzing those cases of insubordination and military unrest in the officer class of the western Roman army, which can be shown to be linked to the slow decline of central authority and the imperial office in the period 395-480. My thesis demonstrates that theories of ‘Warlordism’, as developed in social sciences, can be useful for both the late Imperial west as for other eras of ancient history, such as the late Roman republic. Warlordism was a way of continuing politics, if necessary by military means, when commanders found themselves outside the legitimate framework. Unlike the case of usurpation of the imperial office, when there was little hope of achieving permanent recognition and acceptance, it offered insubordinate officers a chance of returning to the ruling imperial regime depending on circumstances and the success of their resistance. I propose that warlordism functioned as an alternative to usurpation, a tool for military dissidence, fuelled by an economy of violence. Contrary to modern warlordism, the warlordism of the fifth century AD represented a transient phase which no imperial commander was willing to prolong indefinitely. At some stage, given the means, warlords in the western Roman army wanted to become part of the imperial echelon again. Yet these alternative methods of violent opposition, and the acquisition of force through private means, ensured the breakdown of the state’s monopoly on violence and the disintegration of centralized armies. What started as an accidental revolution became a new form of military rule.