台湾海峡西岸重力场变化梯度场图像分析

讨论了应用曲面拟合技术和利用离散的重力观测点的重力变化对特定研究区的重力场变化进行数值模拟以获取该区重力变化空间梯度场图像的具体方法;并应用该方法获得了2004年3月福建安溪3.6级地震前的重力变化空间梯度场图像,发现空间梯度场图像能清晰地反映出地震前重力场群体性变化的差异性;利用此方法对2005年6月~2006年3月间台湾海峡西岸重力场变化进行数值模拟,获得其空间梯度场图像。     

Can the inner gap sparking take place in millisecond pulsars？

The inner vacuum gap model has become the foundation stone of most theories on pulsar radio emission. The fundamental picture of this model is the sparking, which was conjectured to be induced by magnetic absorption of background gamma photons. However, a question is, can the sparking be triggered in the millisecond pulsars (MSPs) with magnetic fields (B) only about 108 G? We investigate this problem by including the pair production above the inner gap. Under the assumption that the magnetic field is dipolar, our results show the background gamma-ray emission can not be the key factor that triggers the sparking, at least not in MSPs with B - 108 G, if the temperature in the polar cap region is only so high as is observed (< 4 × 106 K). Some other mechanisms are required.     

Theoretical and experimental lifetime and oscillator strength determination in singly ionized neodymium (Nd ii)

Radiative lifetime measurements were performed with time-resolved laser-induced fluorescence techniques for 24 levels of Nd  ii in the energy range 20 500–32 500 cm⁻¹. For 17 levels, no previous experimental data exist. These results have allowed the testing of new theoretical calculations with the relativistic Hartree–Fock method taking configuration interactions and core-polarization effects into account, and a satisfying agreement has been found for this complex ion. A new set of calculated oscillator strengths, accurate within a few per cent for the strongest transitions, is presented for 107 lines of astrophysical interest appearing in the wavelength range 358.0–1100.0 nm. These results will be useful to evaluate abundance values of neodymium in chemically peculiar stars in relation with cosmochronology.     

柴达木盆地东北缘古元古代变质镁铁—超镁铁质岩的地质特征及成因探讨

1:5万区域地质调查工作中,在柴达木陆块北缘首次发现古元古代变质镁铁—超镁铁质岩,获得成岩年龄为1952±15Ma,其岩石化学、地球化学特征反映出岩浆来源于亏损地幔,反映出该地区克拉通在古元古代(19亿年)发生了一次强烈的裂解(洋)事件,对于研究柴达木盆地北缘元古代结晶基底地质构造演化及进一步探讨柴达木盆地的起源及构造演化过程提供了重要地质线索。     

On the Line Formation in Stellar Magnetized Atmospheres

1 INTRODUCTIONIn the previous paper (on et al. 1999, hereafter Paper I), we investigated the wavelength-dependence of four colltribution functions (CFs) derived from dmerent formal solutions andreferring to different emergellt quantities in the unpolarized case. Because one cannot generallyassign a single formation region to the whole line band in a real stellar atmosphere, e.g., the solaratmosphere, instead, the line formation region can be defined as the layers deviating farthestfrom t…     

平阳矾山明矾石矿床岩石学特征及其成因浅析

在野外地质工作的基础上，通过对浙江平阳研山明矾石矿床的岩石学及地球化学特征进行认真的研究，进一步证实了矾山明矾山矿床是酸性火山气热液与中酸性火山碎屑岩内的碱性长石的交代中形成的。为了解释矿床的均一性，成矿的周期性和矿床单向依变分带等重要特征，我们重点研究了矿床中明矾石化和叶蜡石化的热力学性质，得出了K 活度和pH值是控制交代产物的重要因素的新结论，提出了该矿床交代成矿作用的新模型，并据此成功地解释了矿床的一些重要特征。     

量子化学方法研究氯代苯酚类化合物对水生物毒性的构效关系

对20个氯代苯酚类化合物进行了CNDO/2量子化学计算,讨论了化合物电子结构与其对水生物翻车鱼(Bluegill)、花鳉鱼(Guppy)、和虾(Shrimp)半致死量之间的关系,分别获得了表示其构效关系的三个线性方程,它们的显著性均远高于α=0.01水平。结果表明:氯代苯酚化合物苯环上碳原子的兀电荷之和(∑Qπ_R)越大苯环上碳原子的净电荷之和(∑Q_R)越大,或LUMO轨道能(E_(LUMO))越低,均使化合物对Bluegill和Guppy水生物的毒性增大;而化合物苯环上羟基邻位的碳原子的兀电荷布居(P_3)越大,同时HOMO轨道能E_(HOMO)越高,则化合物对Shrimp毒性也越大。据此,可预测氯代苯酚类化合物对上述三种水生物的毒性。     

第一代恒星的观测和研究进展

第一代恒星（星族Ⅲ恒星）标志着宇宙从暗物质时代到现在已知的宇宙的转折点。目前对第一代恒星（星族Ⅲ恒星）的观测结果表明，在银河系中还没有发现零金属丰度的恒星，金属丰度[Fe/H]≤-2.5的恒星极少。由于近几年的BPS巡天，银河系中已知的极端贫金属丰度的恒星数目大大增多。目前，可探测到的极端贫金属星的金属丰度[Fe/H]最低约为－4．1。金属丰度在－4到－3之间的恒星大约有100多颗，这些恒星的运动学特性非常类似于其它晕星。然而还没有发现第一代恒星，或金属丰度[Fe/H]≤-5的恒星。关于第一代恒星的形成过程、初始质量函数以及存在于银河系的什么地方，都还没有任何直接的证据。但第一代恒星确实存在。第一代恒星这个谜一般的实体，向观测和理论天文学家提出了巨大挑战。为探测和预言银河系中的第一代恒星，天文学家提出了许多观测方案和理论模型。对有关第一代恒星在观测和理论研究上的进展进行了综述。     

EFFECT OF LIGHT INTENSITY ON THE TOTAL LIPID AND FATTY ACID COMPOSITION OF SIX STRAINS OF MARINE DIATOMS

The effect of light intensity ( 1500 Ix and 5000 Ix) on the total lipid and fatty acid composition of six strains of marine diatoms Cylindrotheca fusiformis (B211 ), Phaeodactylum tricornutum (Bl14, Bl18 and B221) Nitzschia closterium (B222) and Chaetoceros gracilis (B13) was investigated.The total lipids of B13, Bl14, and B211 grown at 5000 Ix were lower than those grown at 1500 Ix. No evident changes were observed in Bl18, B221 and B222. Fatty acid composition changed considerably at different light intensity although no consistent correlation between the relative proportion of a single FA and light intensity. The major fatty acids of the 6 strains were 14:0, 16:0, 16:l(n- 7) and 20:5(n-3) . Cylindrothecafusiformis had high percentage of 20:4n - 6 (9.2 - 10.9% ) . The total polyunsaturated fatty acid /rl all 6 strains decreased with increasing light intensity. The percentage of the highly unsaturated fatty acid eicosapentaenoic acid (EPA) decreased with increasing light intensity in all strains except Chaetoceros gracilis.