Petrogenesis of garnet-bearing ultramafic rocks and associated eclogites in the Su-Lu ultrahigh-P metamorphic terrane, eastern China

Ultramafic blocks that themselves contain eclogite lenses in the Triassic Su-Lu ultrahigh-P terrane of eastern China range in size from hundreds of metres to kilometres. The ultramafic blocks are enclosed in quartzofeldspathic gneiss of early Proterozoic age. Ultramafic rocks include garnetiferous lherzolite, wehrlite, pyroxenite, and hornblende peridotite. Garnet lherzolites are relatively depleted in Al₂O₃ (<3.8wt%), CaO (<3.2%) and TiO₂ (<0.11 wt%), and are low in total REE contents (several p.p.m.), suggesting that the rocks are residual mantle material that was subjected to low degrees of partial melting. The eclogite lenses or layers within the ultramafic rocks are characterized by higher MgO and CaO, lower Al₂O₃ and TiO₂ contents, and a higher CaO/Al₂O₃ ratio compared to eclogites enclosed in the quartzofeldspathic gneiss. Scatter in the plots of major and trace elements vs. MgO, REE patterns and La, Sm and Lu contents suggest that some eclogites were derived from melts formed by various degrees (0.05–0.20) of partial melting of peridotite, and that other eclogites formed by accumulation of garnet and clinopyroxene ± trapped melt in the upper mantle. Both ultramafic and eclogitic rocks have experienced a complex metamorphic history. At least six stages of recrystallization occurred in the ultramafic rocks based on an analysis of reaction textures and mineral compositions. Stage I is a high temperature protolith assemblage of Ol + Opx + Cpx + Spl. Stage II consists of the ultrahigh-pressure assemblage Ol + Cpx + Opx + Grt. Stage III is manifested by the appearance of fine-grained garnet after coarse-grained garnet. Stage IV is characterized by formation of kelyphitic rims of fibrous Opx and Cpx around garnet, and replacement of garnet by spinel and pargasitic-hornblende. Stage V is represented by the assemblage Ol + Opx + Prg-Hbl + Spl. The mineral assemblages of stages VI_A and VI_B are Ol + Tr-Amp + Chl and Serp + Chl ± talc, respectively. Garnet and orthopyroxene all show a decrease in MgO with retrogressive recrystallization and Na₂O in clinopyroxene also decreases throughout this history. Eclogites enclosed within ultramafic blocks consist of Grt + Omp + Rt ± Qtz ± Phn. A few quartz-bearing eclogites contain rounded and oval inclusion of polycrystalline quartz aggregates after coesite in garnet and omphacite. Minor retrograde features include thin symplectic rims or secondary amphiboles after Cpx, and ilmenite after rutile. P-T estimates indicate that the ultrahigh-metamorphism (stage II) of ultramafic rocks occurred at 820-900d? C and 36-41 kbar and that peak metamorphism of eclogites occurred at 730-900d? C and >28 kbar. Consonant with earlier plate tectonic models, we suggest that these rocks were underplated at the base of the continental crust. The rocks then underwent ultrahigh-pressure metamorphism and were tectonically emplaced into thickened continental crust during the Triassic collision between the Sino-Korean and Yangtze cratons.     

在我国发现的Schwertmannite矿物及其特征

采用X射线衍射(XRD)、扫描电镜与能谱(SEM-EDX)、X射线荧光(XRF)、傅立叶红外光谱(FT-IR)、热分析(DTA-TG)等分析方法,在我国山西马兰煤矿的酸性矿坑排水(AMD)沉淀物中首次发现了“斯沃特曼铁矿”(Schwertmannite)。研究表明,山西马兰煤矿酸性矿坑排水沉淀物中的Schwertmannite矿物的粒径为0.3~70μm,且分布比较均匀,其BET表面积为44.065 0 m2/g;SEM二次电子像显示为球形或椭圆形(聚集体)结构,颗粒大小比较均匀,球的表面有针状毛刺;该矿物的化学式为Fe8O8(OH)4.52(SO4)1.74.4.73H2O。     

基于GIS组件技术的地下水资源管理信息系统的研究与开发

分析设计了系统的逻辑结构与功能模块的划分,研究了组件式GIS系统开发模式的相关技术,开发了基于GIS组件技术的地下水资源管理信息系统。采用MapObject 2．0与PowerBuilder 8．0相结合的集成开发方式,应用面向对象技术,实现了GIS的地理信息与地下水资源业务管理的信息处理模块的无缝高效集成。用户不需投资购买专门的GIS开发与应用平台,不需学习和掌握专门的GIS开发语言。     

新一代多普勒天气雷达在强对流天气过程中的应用

介绍多普勒天气雷达产品在2005年4月22-23日强对流天气过程中应用的情况,并对使用多普勒天气雷达产品的过程加以总结,为预报员使用雷达产品预测灾害性天气提供参考。     

赤道东太平洋C-C区硅质沉积物的磁性特征及细菌合成磁铁矿

对分布于赤道东太平洋克拉里昂和克里帕顿断裂带之间 (C-C区 )的硅质沉积物所作的环境磁学研究表明,沉积物的磁性特征由亚铁磁性矿物主导,亚铁磁性矿物颗粒以单畴 (SD)和超顺磁 (SP)为主。磁性参数和透射电镜(TEM )分析表明,该区沉积物中存在着细菌合成的磁铁矿,并观察到磁铁矿存在不同程度的溶解。这一发现是微生物参与C-C区铁元素循环的直接证据。不完整反铁磁性矿物在氧化性较强的西区沉积物中含量较高,且随着纬度升高而增加,显示随着远离赤道,沉积物氧化性趋强.     

水流入渗和气体驱替过程二维问题的耦合求解

采用孔隙介质力学分析方法,把土体骨架、孔隙水和孔隙气体分别作为独立的研究对象,结合孔隙水和孔隙气体在气、液交界面上的力学条件建立耦合方程,研究非饱和土中孔隙水的入渗和孔隙气体的排出过程,为水流入渗问题的求解提供了一种新的方法。将此种方法应用于二维水流入渗问题的数值求解,利用简单的工况校验了这种计算方法的可靠性。通过对砂体和粉煤灰断面进行的二维水流入渗计算表明,孔隙气体的排出过程影响孔隙水的入渗运动。     

甘肃党河南山地区鸡叫沟金矿床成矿特征及成矿模式

通过对鸡叫沟金矿床的成矿地质背景、矿床地质特征、找矿标志及控矿因素等到诸方面分析,指出鸡叫沟金矿床成矿物质主要来源于岩浆岩,矿体主要分布于黑云母花岗闪长岩、超基性角闪石岩岩体与奥陶纪地层的内外接触带上,且受多级断裂裂隙系统控制。矿石类型为石英脉型、蚀变岩型、石英脉＋蚀变岩型,矿化类型主要有黄铁矿化、黄铜矿化、磁黄铁矿化、方铅矿化、毒砂化等。深部岩浆房为矿床形成提供了热动力,矿床成因类型为与岩浆岩有关的低温热液型金矿床,在此基础上,总结归纳了该矿床的成矿模式与综合找矿标志。     

一种实现工业数字摄影测量自动化的方法

在工业数字摄影测量中,当被测物大而复杂时,目标像片的数量可能达到数百张,像点达到几千个,因此人工去识别这些像点是不切实际的,不但费工费时而且也加大了出错率.为了实现工业数字摄影测量的自动化,引入了一种点状编码标志,讲述了其设计原理,并应用透视投影中交比不变量和仿射变换对其进行了识别.试验表明,该编码标志点设计严密,自动识别率为100%,可以满足应用要求.     

Characterization and Expression Analysis of Protein Kinase C Gene from Dunaliella salina

Protein kinase C(PKC) has a crucial role in signal transduction for a variety of biologically active substances which activate cellular functions and proliferation. We previously isolated the full-length PKC gene from Dunaliella salina(Ds PKC) using rapid amplification of cDNA ends(RACE) and RT-PCR methods. And we submitted the mRNA sequence of Ds PKC gene to NCBI(Genbank No. JN625213). In the present paper, the Ds PKC gene open reading frame obtained by PCR was cloned into pGS-21 a vector and transformed into Escherichia coli to generate the fusion protein. Bioinformatics analysis revealed that DsPKC gene was a member of serine/threonine kinase with two conserved domains and highly conserved motifs. The Ds PKC was highly expressed upon induction with isopropyl-β-d-thiogalactoside(IPTG) at a final concentration of 0.2 mmol L~(-1) at 37℃. Under salt stress, the fusion protein Green Fluorescent Protein(GFP)-DsPKC was transferred from the cytoplasm to the cell membrane. The expression pattern of Ds PKC gene was analyzed using real-time quantitative PCR, and indicated that Ds PKC gene was up-regulated by 3.0 mol L~(-1) NaCl at 12 h, which was significantly higher than in control values(P 0.05). These results suggest that the Ds PKC gene plays an important role in response to salt stress in D. salina.     

海洋线虫Litoditis marina酸性pH胁迫响应的转录组分析

工业革命以来,二氧化碳排放导致了海洋酸化。海水pH下降对无脊椎动物的生长发育、繁殖、代谢和免疫等多个生命过程产生重要影响,但海洋无脊椎动物如何感知和响应酸性pH胁迫的分子机制还很不清楚。本研究以团队建立的海洋线虫Litoditis marina品系为模型,对其在不同酸性pH条件下的表型特征及转录组数据进行了分析。结果表明,当pH从实验室最佳生长条件5.92下降到5.33时,L. marina生长发育的速度明显减慢,但依然可以产卵繁殖;但当pH下降到4.33时,L. marina的生长受到严重影响,表现为不能长成成体且不能产卵繁殖。通过转录组数据分析,发现当pH从5.92下降到4.33时,海洋线虫L. marina脂肪酸β-氧化通路基因和不饱和脂肪酸合成相关基因表达上调;表皮相关基因表达则呈现差异变化,2个nas基因和6个ptr基因表达显著上调,表皮胶原基因col类基因的表达没有发生显著变化;细胞色素P450通路相关基因、凝集素C基因和HSP70家族基因的表达量显著上调。当pH从5.92下降到5.33时,上述提到的这些上调基因中的大多数没有发生显著变化。我们发现的海洋线虫应答酸化胁迫的主要调控模式,为理解生物体能够在低pH环境中生存的分子机制提供了参考,为筛选和识别生物体响应和适应酸化胁迫的关键基因奠定了基础。