深海会聚区波导不变量特征研究及应用

为了解决深海会聚区目标及其运动态势难以判断的问题,在研究会聚区形成条件和其声场传播规律以及波导不变量理论的基础上,对典型深海环境不同位置的声强距离-频率分布图中的干涉条纹特征进行理论分析和仿真验证。结果表明,深海会聚区存在与其他区域不同的干涉条纹特征,其对应的波导不变量?值为负。本文提出了利用会聚区特有的干涉条纹特征,对会聚区目标及其运动态势进行初步判断的方法,仿真结果和试验数据表明,判断方法具有可行性和有效性。     

徐淮早白垩世埃达克质岩中含橄榄石单斜辉石岩的成因及其岩石学意义

报道了徐淮地区早白垩世埃达克质岩中首次发现的含橄榄石单斜辉石岩捕虏体的岩相学与矿物化学资料, 该类捕虏体显示堆积结构、块状构造, 主要由单斜辉石(~80%)、斜方辉石(~5%)、橄榄石(~5%)和普通角闪石(~10%)组成.橄榄石外侧发育有斜方辉石反应边, 角闪石沿辉石粒间分布, 呈嵌晶结构.矿物化学分析结果表明: 橄榄石的镁橄榄石分子值(Fo)=77.7~79.3, Ni=623×10-6~773×10-6; 斜方辉石的Mg#=75.6~80.2, Cr=161×10-6~684×10-6, Ni=79×10-6~708×10-6; 单斜辉石的Mg#=84.5~86.4, CaO=21.59%~23.13%, Al₂O₃=1.72%~2.44%.上述矿物与中、新生代玄武岩中橄榄石、斜方辉石和单斜辉石斑晶以及堆积成因辉石岩中的斜方辉石和单斜辉石成分类似.此外, 单斜辉石的稀土配分型式以相对富含中稀土元素的上凸型为特征, 稀土元素含量较低(∑REE=10.14×10-6~12.71×10-6), 无明显的铕异常(δEu=0.90~1.16), 类似于新生代玄武岩中单斜辉石斑晶.捕虏体中的普通角闪石的Mg#=74.0~80.4、SiO₂=43.2%~44.5%、Na₂O=2.04%~2.29%, 稀土元素分馏不明显, 显示亏损高场强元素(HFSEs, 如Nb、Ta、Zr、Hf), 富集Sr、Rb、Ba的特征, 与新生代玄武岩中角闪石捕虏晶成分不同.结合其嵌晶结构, 普通角闪石应是寄主岩浆贯入结晶的产物.综合上述特征, 可以看出含橄榄石单斜辉石捕虏体为镁铁质岩浆高压堆晶成因.结合华北克拉通东部早白垩世双峰式火山岩组合的出现, 推断含橄榄石单斜辉石岩捕虏体可能是早白垩世基性岩浆底侵的产物.      

热带浮游植物将被迫“搬家”去极地?

浮游植物指悬浮于水中的微小藻类植物,是浮游生物中的自养生物部分。浮游植物广泛存在于河流、湖泊和海洋中,多分布于水域的上层,个体极小,需要用显微镜才能观察到,繁殖极快。在淡水中主要是蓝藻、绿藻、硅藻等,在海水中主要是硅藻、甲藻。     

Telecorrelation of the 500 hPa Polar Circulation and El Nino / SO with the Temperature Fields in China

By using the monthly data from 1951 through 1984, empirical orthogonal expansion is performed for the 500 hPa geopotential height north of 65°N and the canonical fields are clustered by fuzzy classification. It is noted that both the mean monthly polar vortex fields and the large-scale anomaly fields fall into three regimes, with those of the January mean field and th April anomaly field having characteristic features. In addition, the relationship between the time weigthing coefficients of the canonical fields and El Nino / SO is examined, showing significant anomalies in the large-scale polar anomaly fields during April and October of the year when El Nino occurs. These polar circulation anomalies have considerably influenced the temperature fields in China during April and October. Thus, we may conclude that this is one of the most important reasons for a relatively cool April and a warm October in China during the El Nino year.     

鄂尔多斯盆地南部旬邑-宜君地区直罗组古层间氧化带地球化学特征及水-岩作用探讨

鄂尔多斯盆地南部旬邑-宜君地区直罗组古层间氧化带具有明显分带特征,通过对不同分带砂岩主量、微量、稀土元素及环境敏感参数特征对比研究,将旬邑-宜君地区古层间氧化带发育的水-岩作用过程划分成两个阶段：古层间氧化带形成和大规模成矿阶段、二次还原改造阶段。(1)古层间氧化带形成和大规模成矿阶段：含氧水进入目的层砂体,使砂体中Fe²⁺氧化成Fe³⁺(Fe²⁺含量最低,Fe³⁺最高);砂体中的U被氧化为U⁶⁺,形成铀酰腐殖酸盐络合物发生迁移(U、Corg、S含量最低、Th/U比值最高);长石高岭土化使Si发生流失(SiO₂含量降低);携带大量U的氧化流体运移至氧化还原过渡带(Corg、∑S含量最高、Fe²⁺含量仅低于灰绿色砂体),还原剂(有机质和黄铁矿等)将U⁶⁺还原成U⁴⁺,形成沥青铀矿;U⁴⁺与SiO₄^4-发生反应形成铀石(Th/U比...     

甘肃北山前红泉地区水系沉积物地球化学特征及找矿方向

前人在研究区开展过1∶20万水系沉积物测量及重砂测量,但受比例尺限制,异常面积过大,查证目标不够明确,找矿效果不佳。本次通过对前红泉地区开展1∶5万水系沉积物测量工作,初步总结了该区地球化学特征,根据元素组合特征、成矿地质条件等圈定出综合异常10处;在分析综合异常特征、异常检查情况及成矿潜力的基础上划分了成矿远景区4个,分别为受断裂和韧性剪切带控制的万岁山金成矿远景区、黑山头金多金属成矿远景区、与基性岩有关的帐房山铜钴镍成矿远景区及受酸性岩体内构造裂隙控制的红柳疙瘩钨成矿远景区;在成矿远景区内优选出找矿靶区4处,并提出了下一步找矿工作的建议。     

孙吴地区中侏罗世白云母花岗岩的年代学与地球化学:对蒙古-鄂霍茨克洋闭合时间的限定

本文对孙吴地区白云母花岗岩行了锆石LA-ICP-MS U-Pb年代学和岩石地球化学研究,确定其形成时代、岩石成因,从而揭示区域构造背景。孙吴地区白云母花岗岩中的锆石均呈半自形-自形,振荡生长环带明显,暗示其岩浆成因。测年结果显示,白云母花岗岩形成于168Ma,为中侏罗世岩浆事件的产物。岩体具有高硅(Si O2=74.61%~80.16%)、富铝(Al2O3=10.59%~13.90%)、贫铁(Fe2O3=0.11%~0.3%)等特征,在化学上属于准铝质-过铝质(A/CNK=0.97~1.13)系列。孙吴地区白云母花岗相对富集轻稀土元素(LREEs)和大离子亲石元素(LILEs),亏损重稀土元素(HREEs)和高场强元素(HFSEs)。锆石的εHf(168Ma)=+7.53~+11.66,二阶段的模式年龄(tDM2)变化于595~966Ma之间。上述特征表明,孙吴地区中侏罗世白云母花岗岩的岩浆起源于新增生加厚陆壳物质的部分熔融。结合在大兴安岭与小兴安岭衔接地区变质杂岩和冀北-辽西地区区域性地层不整合面的存在,表明大兴安岭西坡-冀北-辽西地区中侏罗世经历了一次与蒙古-鄂霍茨克洋闭合有关的陆壳加厚过程。因此,研究区内中侏罗世白云母花岗岩的形成应与蒙古-鄂霍茨克洋闭合过程中的陆-陆碰撞作用有关,而与古环太平洋向欧亚大陆的俯冲作用无关,其形成时代也限定额尔古纳地块西北部蒙古-鄂霍茨克洋的闭合时间应为中侏罗世。     

Genetic study of Kelp “901” strain

Based on DNA extraction and optimization of random amplified reaction (RAPD) to the gametophytes and sporophytes of Kelp “901” strain, genetic study on variation was conducted to its parents and offsprings of F6, F7,Fs, and F9 generation. RAPD results have shown that among 30 selected primers for gametophytes, 297 loci ranging from 200 to 3 000 bp were obtained in the average of 9,9 loci for each primer, This indicated a high polymorphic rate with RAPD detection. UPGMA (unweighted pair-group method arithmetic average) analysis showed that each male and female gametophyte of a generation could be clustered into one pair separately. The genetic distances of the Kelp 901 generation were 0.321 2-0.476 7, and the maximum was between F7 and Fs (0.476 7). Identity analysis showed that F6 generation was more close to the female parent (0.659 3), and F7 generation was more close to the male parent (0.5788). To the sporophytes study in 24 selected primers for RAPD amplification, 191 loci ranging from 230-2 800 bp were obtained, in the average to each primer of 8.0 loci. The heterozygosity to six populations were male parent (0.223 9),female parent (0.107 2), F6 (0.216 4), F7 (0.228 6), F8 (0.229 6) and F9 (0.317 2). The nearest genetic distance was 0.083 5 (Fs, F9). Total heterozygosity (HT) ofF6, F7, F8 and F9 generations was 0.318 6, the average heterozygosity (Hs) for F6,F7, F8 and F9 generations was 0.248 0, and deduced coefficient of population differentiation (Gst) was 22.2%. Six sequence characterized amplified regions (SCAR) were preliminary screened through RAPD analysis. It needed to be verified in detail as they are significant for molecular marker assistance in breeding and selecting Laminaria.