The equation-of-states of Jilin ordinary chondrite and Nandan iron meteorite

Shock wave data for Jilin ordinary chondrite and Nandan iron meteorite are measured by electric-pin techniques on the dynamic high-pressure device equipped with a two-stage light gas gun, and then equation-of-states supposedly fit for describing their P-V-E relations are chosen to evaluate the values of their parameters. Demonstrated from the comparison between P-V curves of equation-of-states and experimental data points, P-V relation of Jilin ordinary chondrite can be described by the universal equation-of-state, of which bulk modulus value of zero-pressure K0s = 48.10 GPa, its pressure derivative K’os = 4.13. That of Nandan iron meteorite can be described by the three-term form of equation-of-state, of which the values of two matter parameters Q = 41.23531 GPa, 5 = 12.271 79. The Hugoniot data and equation-of-states for Jilin ordinary chondrite and Nandan iron meteorite are first reported in this paper. The equation-of-state defined by Hugoniot data measurement provides strong empirical support for

Melting Behaviour of Mo by Shock Wave Experiment

In order to clarify the apparent discrepancy in determinations of melting temperature Tm of Mo between diamondanvil cell （DA C） measurements from 0 to about 100 GPa and shock wave （SW） measurement at only one pressure of about 390 GPa by comparison with visual extrapolation, we perform SW experiments to replenish more Tm data on purpose to make this comparison more directly and rationally as well. The techniques adopted consist of Hvgoniot sound velocity measurement for porous Mo and shock-induced release Tm measurements for both solid and porous Mo. Totally five SW Tm data, which extends the measured pressure range from previous about 390 GPa down to about 136 GPa that is close to the highest pressure （about 100 GPa） attained by previous DAC experiments, are therefore obtained. These measured Tm data, other than the extrapolated as mentioned above, exhibit a manner of continuous variation with pressure and can be fitted well with Lindemann melting description. More significantly, the measured Tm data at lowest pressure are still much higher than that of the DACs and the overall trend of these Tm data is against to the two-segment melting curve model, with a sudden change in dTm/dp at about 210 GPa, previously proposed by Errandonea [Physica B 357 （2005） 356]. Though the problem of large discrepancy in Tm data measured between DAC and SW has not been completely explained, our knowledge on this matter achieves indubitable progress since it is of value to programme the next clarification. Some suggestions for further clarifying the issue of large discrepancy between DAC and SW measurements are also proposed.

Observation Constraints on the Simplified GCG Model

A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 （a redshiR of cosmic phase transition from deceleration to acceleration）.

费米超流体的类振荡膨胀（英文）

在强相互作用的费米气体的研究中,原子团的膨胀动力学过程的测量是获取强相互作用费米气体性质的重要手段之一.由于制备的原子团原子数少(~10~5)和温度高(~0.1T_F),此前的研究工作中强相互作用费米气体的膨胀过程通常仅能维持几毫秒.因此,本文首先制备出了大原子数(5×10~6)和极低温度(0.06(1)T_F)的费米超流.结合特殊的磁场设计,作者成功地观测到了长达30ms的费米超流体的类振荡膨胀过程.同时,作者测量了费米超流体的指数型状态方程,得到了准震荡频率与相互作用、温度的关系.该实验结果和方法将促进对费米超流诸多有趣现象的研究,如椭圆流、正常-超流相变和super-Efimov效应等.