微细矿物的湿式电磁分选

单矿物分选是矿床成因、综合评价和物质成分研究等工作中的重要环节。单矿物分选的纯度,直接影响化学分析、x-光分析、光谱分析、同位素年龄测定、红外光谱、矿物的物理性质测定等的测试数据的精度,必须予以重视。但目前的单矿物分选方法远不能满足实际工作的需要,特别是对微细矿物的分选,更感困难。由于矿物间普遍存在着磁化系数的差异,因此,磁选仍然是广泛应用的方法。其中,等磁力型磁选机(Franz型,我国的wcF型)分选200目以上样品的效果是比较理想的,但对200目以下样品的效果,急剧降低。在解决微细矿物的分选问题中,如能扩大等磁力型磁选机的应用范围与     

细胞自动生成破裂模型中非均质性对破裂形成的影响

岩石破裂是个复杂的过程，它一般涉及到破裂过程的复杂性和多样性，以及材料的非均生。因此，必然要采用理论方法建立破裂模型。本文根据破裂系统的基本物理特征，充分考虑点阵要素的非均质性，试图遵循一定规则来建立破裂模型，模拟控制地震形成的破裂过程。     

Modelling the VUV emission spectrum of N2: preliminary results on the effects of rotational interactions on line intensities

A theoretical model of the excited singlet ungerade electronic states of the nitrogen molecule is presented. This work is an extension of a previous study (D. Stahel, M. Leoni and K. Dressler, J. Chem. Phys. 79, 2541-2558, 1983) with the addition of rotational interactions between states of different symmetry. These rotational interactions together with the homogeneous couplings frequently lead to extreme mixing of the states. This model is being used to analyse the high resolution vacuum ultraviolet emission spectrum which is currently being recorded photoelectrically. The ultimate goal of this work is the reliable interpretation of the low resolution emission spectra observed from planetary atmospheres, notably that of Titan, and the transitions assigned as being important in the Voyager 1 spectra of Titan are discussed in detail.     

Population and resources in Mauritius

"The island of Mauritius was facing a crisis by the 1950s as the relationship between its population and resources became unbalanced....A two-pronged strategy was set in place to change the relationship between population and resources. Firstly, an aggressive family-planning policy was established, reducing population growth. Secondly, the economy was diversified with tourism, financial services and, especially, manufacturing in the Mauritius Export Processing Zone, creating extra finance and resources. The changes have not been cost-free but Mauritius ends the century, not as a classic case of overpopulation, but more [as] a model micro-state that has overcome many population and resource problems, largely through its own efforts."     

Endocrine disruption in a marine amphipod? Field observations of intersexuality and de-masculinisation

Intersexuality has been found in both males and females of the marine/estuarine amphipod, Echinogammarus marinus, at polluted and reference sites in East Scotland. Polluted sites had significantly more intersex specimens than reference sites, however the cause of intersexuality is unclear. Discriminant analysis of morphometric data showed that normal male specimens from the most polluted site resembled pooled intersex males, suggesting that subtle endocrine disruption (ED) maybe occurring in these otherwise apparently normal males. The main discriminating character was gnathopod size, recognised to be under androgenic gland control. The association of distinctive morphometry with intersexuality may provide a new approach to biomarkers of ED in crustaceans. The opportunities for other novel biomarkers, for example biochemical or behavioural markers, may also be explored through study of intersex animals.     

2002年11月一次深秋暴雨浅析

深秋暴雨是小概率事件 ,本文对发生于 2 0 0 2年 11月 15日的一次深秋暴雨天气过程进行了分析 ,分析表明 ,中低层的切变线的存在与稳定少动 ,强度的不断增强是本次暴雨发生的直接原因 ;而南支强于北支 ,低槽北抬 ,北抬后维持在 30°N附近 ,并形成了强烈的风向和风速切变。