森林沼泽区富含有机质样品中金的存在形式及对分析的影响

为探讨中国东北森林沼泽地区富含有机质样品中金偏低的原因,采用了王水溶矿法和四酸溶矿法的AAS分析来测定样品中的Au.用四酸溶矿法驱除硅胶,明显地提高金的测定值,特别是对含量大于10-9的样品,2种分析方法的差别更大.通过以上研究发现,在森林沼泽区的富含有机质样品中,金除以有机质结合形式存在于介质中,还可能以胶体或纳米形式存在于样品中,并被SiO2胶体所包裹,在高浓度有机酸的保护下,金能在水溶液中呈活动形式做长距离迁移;但用王水溶矿法不能测定出这种被SiO2 胶体包裹形式的金.     

洞穴石笋沉积特征研究--以贵州荔波董歌洞4号石笋为例

在综合研究南方20多个大型石笋纵剖面的基础上,以董歌洞4号石笋为代表,论述石笋沉积特征与气候演化的对应性.4号石笋从距今147.838±2.6 ka开始沉积以来,形成了53个沉积纹(壳)层组,组成24个亚旋回,构成9个旋回,呈现韵律式旋回性沉积特征.石笋纹(壳)层组分、结构、叠复构造呈多级次旋回性很突出,其中沉积间断具普遍性、沉积速率具多变性,间断和速率变化级次亦明显.以系统测试和测年引证沉积特征的同时揭示:①~⑨旋回间沉积间断时间累积达75.804 ka,占石笋形成时间的51.21%,①~⑨旋回实际沉积时间仅72.222 ka,占形成时间的48.79%;④旋回之前,沉积速率很小,最小仅0.36 mm/100a,比最大速率小22~24倍,自⑤旋回起,沉积速率很大,最大达39.03 mm/100a,是最小速率的3.8倍.石笋沉积特征与气候环境演化的成生关系表明,石笋沉积多旋回性的纹(壳)层组、亚旋回、旋回与气候演化的气候期、阶段和旋回彼此对应,石笋沉积的多级次旋回及其变化就是气候演化的级次及旋回性转(跃)变时间,彼此同时显示.论证了石笋沉积的多旋回性与气候演化的不稳定性,及其彼此协调的宏观、微观综合表现特征.     

一种辐射成像三维可视化系统的实现

辐射成像技术在医疗诊断、无损检测和工业探伤领域有着重要的应用,三维可视化技术与辐射成像技术的结合有助于帮助人们以更直观和形象的方式对病灶和被检物进行检查,从而提供更为有效的信息和检查结果。本文介绍了一种基于辐射数据而构建的三维可视化系统的实现,通过系统分析和整体设计,模块级的实现、交互控制和界面设计等四个方面阐述了基本思路,对于辐射成像可视化系统的研究有一定的借鉴意义。     

Relationship between petroleum reservoir rocks and source rocks

A substantial fraction of sandstones containing commercial quantities of oil are proposed to be in contact with source rocks which produce oil. For these situations the quantity of oil collected in a sandstone is proportional to the area of contact with a source rock of relatively low permeability, rather than to the total thickness of the potential source rock. It is inferred that source rocks along the upper or lower faces of a sandstone should produce more oil into the sandstone than source rocks lateral to the sandstone. Semiquantitative estimates of the thickness or width of required source rock are obtained. The arguments and results are based on published statistical studies and the assumption that a degree of geometrical similarity exists among sandstones.     

中小流域水资源合理调蓄问题

一个流域内既有地表水资源,又有地下水资源,如何根据本流域的自然地质条件更合理地开发利用这些水资源,是个战略决策问题。本文以典型流域为实例,对适宜地表及地下调蓄水资源的条件进行了分析,对中小流域水资源合理调蓄问题提出了笔者的看法。     

Allometry in the pliocene bivalveAstarte omalii: A new look at an old data set

The relationships between ontogeny and phylogeny have been studied for the bivalve Astarte omaliifrom the Lower, Middle, and Upper Pliocene of Belgium using canonical variates analysis, principal components in the form of multivariate allometry, and bivariate power functions or allometric equations. The results indicate that the three samples represent segments of a single evolutionary lineage which is characterized mainly by paedomorphosis where adult descendants are similar to juvenile ancestors. Recapitulation or peramorphosis is only observed for a single parameter. The Lower and Middle Pliocene samples are considered as Astarte omalii omalii,whereas the Upper Pliocene specimens are placed in A. omalii basteroti.The evolutionary trends most likely reflect changes in the living positions of the bivalves.     

About stability of libration points in the restricted photogravitational three body problem

Nonlinear stability of the triangular libration point in the photogravitational restricted three body problem was investigated in the whole range of the parameters. Some results obtained earlier are corrected. The method for proper determination of cases when stability cannot be determined by four order terms of the hamiltonian was proposed.     

Two-step interface and velocity inversion—— Study o e of the Tangshan seismic region

ｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｔｅｎｙｅａｒｓ,ｒｅｓｅａｒｃｈｅｓｏｎｔｈｅ３Ｄｃｒｕｓｔａｌｓｔｒｕｃｔｕｒｅａｎｄｔｅｃｔｏｎｉｃｓｈａｖｅｂｅｅｎｐａｉｄｍｏｒｅａｎｄｍｏｒｅａｔｅｎｔｉｏｎ,ｓｔｕｄｉｅｓｏｆｒｅｌｅｖａｎｔｍｅ...     

中国粮食总产量结构分析与丰歉评估

对中国粮食总产量的结构分析表明：①粮食作物平均单产的变化在粮食总产量的变化中约占２／３以上,起着决定性的作用;②５０年代以来,小麦,玉米产量在粮食总产量中的份额呈增加之势,而水稻所占份额相对稳定,大豆等其它作用的份额则有下降趋势;③就主要粮食作物单产而言、一季稻的产量为最高,小麦产量的增长为最快。通过分析中国粮食作物平均单产的丰歉与气象条件的关系发现;西北和东北地区的降水量,华北地区的积温与产量丰     

双星系中两子星的自转对双星轨道变化的后牛顿效应

本文利用解摄动方程的平均值法求得在PPN框架中二体自转对轨道要素产生的后牛顿效应的长期变化影响．利用这一理论对CWCep和DRVul两颗双星中两子星的自转对轨道近星点和平近点角的长期摄动的后牛顿效应做了计算。结果表明：对于两个质量较大快速自转的子星,由此所产生的后牛顿效应的摄动量是不能忽视的。