高溶解性气体浮选

溶气浮选是一种高效的,但也经常是费用高的工艺过程。该过程用于从水和废水中去除悬浮固体和乳化液,在除油、活性污泥澄清和浓缩。除藻类方面已获得应用。在研究低费用方法方面,出现了使用水溶性较高的气体这一概念。这一方法能够减少要求的溶解有气体的回流量;这一回流和固体流量控制着浮选池的大小,用于处理的气体体积也将减少。     

土库曼地区沙漠化进程的预测

在预测沙漠化时,自然和人为因素都应加以考虑。在自然因素中,气候的变化起着主要的作用,而且无法预料。然而,人类大范围的经济活动必将影响下述小气候的变化。沙漠牧场的改良和农业灌溉会引起地表水和地表物理特性的极大变化。秋冬季半灌木和灌木牧场的建     

1982年数学地质概况

<正> 许多地质数据组都是由较少的几个端元组分混合而成的,一般的解释手段是把一组数据分解成不同的组分。例如,古生物学家把化石必须分成几个环境族,岩石学家必须区分组成熔岩流系列的母岩浆,沉积学家一定要判明采集区沉积物样品中重矿物的不同源区。在纯的端元组分采集不到时,当然需要一种特殊     

岩浆活动与大陆分裂的年代关系

引言 目前人们公认大陆断裂与基性和硷性火成岩的喷出和侵入活动有关。许多作者(例如Dietz & Holden,1970;Davies,1968;Grasty & Wilson,1967)曾利用基性和硷性火成岩的年龄来说明大陆分裂的年代。从而说明大洋地壳最早期建造的年代。大家也公认断裂带中最早出现的海洋沉积物与大陆分裂有时相的(temporally)关系(Smith & Hal     

The hand of birds revealed by early ostrich embryos

The problem of resolving the homology of the digits of the avian hand has been framed as a conflict between paleontological and embryological evidence, the former thought to support a hand composed of digits I, II, III, because of similarity of the phalangeal formulae of the earliest known bird Archaeopteryx to that of Mesozoic pentadactyl archosaurs, while embryological evidence has traditionally favored a II, III, IV avian hand. We have identified the critical developmental period for the major features of the avian skeleton in a primitive bird, the ostrich. Analysis of digit anlagen in the avian hand has revealed those for digits/metacarpals I and V, thus confirming previous embryological studies that indirectly suggested that the avian hand comprises digits II, III, IV, and was primitively pentadactyl.     

安大略柯克兰莱克克尔艾迪生太古代脉金矿床的热液蚀变分带和金的富集

克尔艾迪生——阿伯蒂比带中的一个大型太古代脉金矿床,位于紧靠区域性构造破裂——柯克兰莱克-拉尔德莱克断层带南面的一个滑石-碳酸盐和绿泥石-碳酸盐岩带中。残余的火山结构连同活动性比较低的特征元素的比值表明,矿体的围岩原来大多是镁铁质和超镁铁质岩石及其派生的碎屑岩。 CO_2与碱金属饱和指数移动平均值的投影与金丰度变化的惊人一致,说明金的富集作用与热液蚀变有成因联系。就大范围来说,金富集在柯克兰莱克-拉尔德莱克断层带以南,就细部来说,富集在碳酸盐-白云母型蚀变和碳酸盐-钠长石型蚀变之间的过渡带中。 金富集在柯克兰莱克断层带的一侧被认为是由氧化态梯度变化产生的交代分带所造成的,贵金属富集在还原的一侧。柯克兰莱克-拉尔德莱克断层带南面的蚀变类型分带代表了与外生流体的成分相适应的、连续而逐渐加深的岩石变化过程的不同阶段。连续产生的断裂组合和矿脉有着相同的蚀变型式,因此,流入的热液流体的成分看来在整个时期中基本上没有发生变化。 克尔艾迪生矿山的金矿化及其邻近的蚀变晕被解释为周期性出现的水力压裂、流体渗透及其与岩石的局部反应所造成的结果。流体-岩石的相互作用使流体的成分发生了侧向变化,导致了金的富集(这可能是由于pH值梯度变化的缘故),使金优先富集在?     

Is the Newly Described Vietnamese Bovid Pseudonovibos spiralis a Chamois (Genus Rupicapra)?

 The “Linh Duong” (Pseudonovibos spiralis), a newly described Vietnamese bovid, has been shown to be related to the Caprinae on the basis of the mitochondrial cytochrome b gene sequencing from horn fragments. To integrate the greatest available biodiversity we performed a new phylogenetic analysis including all genera of Caprinae. Unexpectedly, Pseudonovibos is found to be robustly associated with Rupicapra, and closer to the Alpine than to the Pyrenean chamois. Several clues led us to interpret this result as a carry-over DNA contamination of Pseudonovibos by Rupicapra. Received: 19 July 1999 / Accepted in revised form: 20 October 1999     

白洋淀地区的多氯联苯污染研究

对白洋淀地区不同类型纸厂排水口底泥及保定市排污渠底泥进行了ＧＣ／ＥＣＤ分析，可萃取有机氯（ＥＯＣｌ）含量测定，检出了多氯联苯和有机氯农药。用截止分子量为１０００道尔顿的透析袋方法对相应地区的水体进行了检测，发现水体中可检出含氯农药六六六，但多氯联苯等由于水中存在浓度低未能检出，同样样品的ＧＣ／ＭＳ／ＣＯＭ结果表明，水体中主要存在的亲脂性有机污染物为：蒽酮、蒽二酮、苯胺、氯代烃、邻苯二甲酸酯类和苯系物。     

The hierarchy and spatial characteristics of ecosystems: A reconsideration of the ecosystem concept (II)

This paper, based on the autonomy concept, continues to investigate hierarchical forms and spatial structure of ecosystems. The former can lead to limits for the selection of the component parts of an ecosystem and a distinction between its endogenous and exogenous variables; and the latter can be lead to a hypothesis of the space of an ecosystem: the space of an ecosystem = its habitat area + supporting area + impact area, and two characteristics of ecosystems, space-overlapping and the area of ecosystem space, have been further studied referring to human activities.