攀西地区红格钒钛磁铁矿床地球化学异常特征分析及矿床成因探讨

攀西地区基性-超基性含矿岩体以赋存超大型钒钛磁铁矿矿床而闻名于世,是我国重要的铁矿产地和重要的钒钛资源基地.通过对该矿床的地质特征、构造与围岩对成矿的控制作用及地球化学异常特征分析研究,认为红格钒钛磁铁矿成矿物质来源于上地幔,玄武岩浆结晶分异过程中有地壳物质混入地幔物质.矿床的形成对时间与空间要求严格.基性-超基性岩、灯影组白云质灰岩和峨眉山玄武岩是形成红格钒钛磁铁矿床的必要条件.     

东海油气资源区海底沉积物的工程地质特征

根据2001年6月的航次调查及随后的沉积物样品的试验室分析资料,从物理性质和力学特征各方面对东海油气资源区海底沉积物进行了综合工程地质特征研完。发现本区沉积物结构、剪切特征、含水量和液塑限随深度的变化而变化;本区海底沉积物类型既分布有中砂、细砂和粉砂3种砂性土,也分布有扮质粘土、淤泥质粘土和粘质扮土3种粘性土,沉积物的物理力学性质与相立的土类性质相一致。     

南黄海北部盆地东北凹陷烃源岩的早期预测

烃源岩评价是沉积盆地油气地质研究的重要组成部分,尤其对油气勘探初期的战略选区与决策至关重要.南黄海北部盆地东北凹陷的油气勘探程度极低,至今尚无探井揭示烃源岩的发育特征,因此制约了凹陷的油气勘探进程.基于地质类比原理,采用与其相邻类似凹陷--北部凹陷综合对比的方法,应用层序地层、沉积相、地震相分析及含油气盆地动态数值模拟等技术,分析了东北凹陷主要烃源岩层的空间展布和生烃演化特征,并初步形成了一套适用于勘探程度低的地区烃源岩早期预测的方法技术流程.研究表明,南黄海北部盆地东北凹陷发育上白垩统泰州组主力烃源岩系,具有广阔的油气勘探前景.     

西北冰洋表-底层碳动力学耦合作用的同位素(13C,234Th)指示

The coupling of upper ocean-benthic carbon dynamics in the ice-free western Arctic Ocean(the Chukchi Sea and the Canada Basin) was evaluated during the late July–early September 2003 using natural stable(13C) and radioactive(238U-234Th) isotope tracers. POC export flux estimated from 234Th/238 U disequilibria and dissolved CO2 concentration([CO2(aq)]) pointed out that the strengthened biological pump in the Chukchi Shelf have significantly lowered [CO2(aq)] and altered the magnitude of isotopic(12C/13C) fractionation during carbon fixation in the surface ocean. Further, d13 C signatures of surface sediments(d13Csed) are positively correlated to those of weighted d13 CPOC in upper ocean(d13Csed =13.64+1.56×d13CPOC, r2=0.73, p0.01), suggesting that the POC isotopic signals from upper ocean have been recorded in the sediments, partly due to the rapid export of particles as evidenced by low residence times of the highly particle-reactive 234 Th from the upper water column. It is suggested that there probably exists an upper ocean-benthic coupling of carbon dynamics, which likely assures the sedimentary d13 C record an indicator of paleo-CO2 in the western Arctic Ocean.     

Heterosis and heritability estimates for the survival of the Pacific white shrimp (Litopenaeus vannamei) under the commercial scale ponds

The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp(Litopenaeus vannamei) for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids,the heterosis ranged from –11.37%(UA1×UA2) to 20.53%(UA3×SIN) with an average of 0.953%. The results showed that more than half of the hybrids(51.85%) have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero(P0.05). The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.     

冲绳海槽北部表层沉积物中的钙质超微化石及其环境特征

为探讨冲绳海槽表层沉积物中钙质超微化石的分布规律及其影响因素 ,对海槽北部槽坡区 ( 2 9°5 8.33′— 31°31 .2 3′N ,1 2 7°39.5 5′— 1 2 8°5 9.61′E) 34个表层样品进行了分析和研究。共发现 35种钙质超微化石 ,其中优势种为Gephyrocapsaoceanica、Emilianiahuxleyi和Florisphaeraprofun da ;G .oceanica、E .huxleyi等的百分含量变化和特征属种U .tenuis的出现 ,表明该区钙质超微化石组合面貌与东海外陆架相似 ,和东海及南海都属于北太平洋中央水团组合。G .oceanica的含量与海水营养盐存在一定的关系 ,但两者之间并不存在明显的正相关性 ;暖水分子U .irregularis、U .sibogae和O .fragilis的较高含量和冷水分子G .caribbeanica和Calcidiscusleptoporus的较低含量 ,进一步反映该区钙质超微化石的分布受到黑潮及对马暖流的影响 ,其中温度、盐度和表层海水结构性质 ,如海水透明度等因素可能为主要控制因素。     

Fatigue Behavior of Plain Concrete Under Biaxial Compression: Experiments and Theoretical Model

The effects of different lateral confinement stress on the fatigue behavior of and cumulative damage to plain concrete are investigated experimentally. Eighty 100 mm x 100 mm x 100 mm specimens of ordinary strength concrete are tested under constant- or variable-amplitude fatigue loading and lateral confinement pressure in two orthogonal directions. A fatigue equation is developed by modifying the classical Aas-Jakobsen S-N equation for taking into account the effect of the confined stress on fatigue strength of plain concrete. The results of variable-amplitude fatigue tests indicate that the linear damage theory proposed by Palmgren and Miner is unreasonable in the biaxial stress state. A nonlinear cumulative damage model that could model the effects of the magnitude and sequence of variable-amplitude fatigue loading and lateral confinement pressure is proposed on the basis of the evolution laws of the residual strains in the longitudinal direction during fatigue tests. The residual fatigue life predic     

辽东本溪林家组属于中三叠世之锆石、古生物和地层证据

林家组出露于辽宁东部本溪林家崴子一带.自小林贞一1942年记载以来,其时代一直有很大的争议.争议跨度从第三系到上二叠统.20世纪80年代初,张武等依据动植物化石和地层对比,提出了林家组属于中三叠世的观点.由于林家组产出的植物化石十分复杂,既有古生代,又有中生代分子,且没有锆石年龄证据,故林家组时代仍然存疑.近年来,在林家组底部找到了变质凝灰质粉砂岩,其中有很多锆石.根据30颗保存较好锆石测年结果,发现4颗最年轻锆石的206Pb/238U平均年龄是239.5±4.1 Ma.另外,最近前甸子地区林家组发现了少林肋木（Pleuromeia shaolinii）.因此尽管林家植物群存在二叠纪和三叠纪均有分布的重要植物,但结合锆石定年、地层对比、岩性特征、平行不整合接触关系、三叠纪代表植物及中三叠世到早白垩世均有分布的昆虫索德蠊属来综合分析,可以确认林家组确实属于中三叠世.     

利用全站仪直线放样功能测量定线的精度分析

针对测量定线过程中出现的问题,介绍了全站仪直线放样功能用于测量定线的基本原理,并对测线上的转点和整条测线进行了精度分析。为了提高测线精度,提出了依据实地观测条件,分别在各测线段引入转点分段测量的方法。     

基于DMN的高光谱图像分割方法研究

简述高光谱遥感光谱特征体系(包括光谱曲线特征、光谱变换特征和光谱度量特征3个层面)。研究马尔科夫网的概念和方法,生成基于光谱角(SA)特征度量的DMN,并以DMN为证据对高光谱图像进行分割;研究和实验表明基于SA信息的马尔科夫网可以很好地综合高光谱数据空间特征与光谱特征间的关系,为进一步数据处理提供优化控制(其实质是概率神经网络)。最后提出未来应用和研究方向。