岩石圈伸展对粤北下庄矿田铀成矿的制约机制研究

地球动力学与成矿关系的研究是地球科学研究的前沿领域，而陆内岩石圈伸展与成矿的关系的研究则是该领域相对比较薄弱的环节。 华南地区于白垩—古近纪发生了岩石圈强烈的伸展减薄事件，且岩石圈伸展减薄与该区同时期形成的众多金属和非金属矿床有密切的成因联系，尤其是华南地区的花岗岩型热液铀矿床，显示了与该区岩石圈伸展作用可能有多方面的成因联系。粤北下庄铀矿田位于位于南岭铀-多金属成矿带的南部，是华南地区典型的花岗岩型热液铀矿区，本次研究在深入细致的野外地质工作的基础上，运用流体包裹体地球化学、元素地球化学、同位素地球化学等方法手段，开展了对下庄铀矿田成矿流体性质、成矿过程中元素的活动规律、成矿流体来源及演化等方面的系统研究，初步探讨了岩石圈伸展对该区铀成矿的制约机制，并建立了可能的矿床成因模式。通过研究，本次工作获得了以下几点主要认识： （1）通过对下庄铀矿田部分铀矿床流体包裹体显微测温、激光拉曼光谱及液相成分分析研究，查明了下庄矿田铀矿床矿前期热液属中高温（200℃~350℃）、低盐度（0.72%~5.95%NaCl）、密度中等（0.703~0.830g/cm3）、活动深度较深（2.29km~5.74km）、富∑CO2、相对还原性质的流体；成矿期热液属中低温（主要为154℃ ~250℃）、低盐度（0~1.83%NaCl）、密度中等（0.628~0.867g/cm3）、活动深度较浅（0.19km~1.62km）、富F-、相对氧化性质的流体。 （2）矿石矿矿物电子探针测试分析及岩、矿石的微量元素地球化学分析研研究表明，本区铀矿床主要的原生铀矿物为沥青铀矿、铀石、钛铀矿，铀矿物的形成与Si、Ca、W等元素有密切的关系，而其它金属元素未显示明显地富集。矿石、脉石矿物部分继承了原岩的稀土元素组成，且在原岩基础上又有高度的演化。 （3）进行了矿区内碳酸盐的C、O同位素和黄铁矿的He、Ar稀有气体同位素的分析研究。研究表明，矿化剂∑CO2主要为幔源，大量的He、Ar等稀有气体也来自于地幔。矿区发育的深大断裂构造可能控制了幔源挥发份的加入。 （4）脉石矿物碳酸盐和萤石的Sr、Nd同位素地球化学研究显示，成矿流体中的这些元素主要源于地壳，南区矿床（338、339）的Sr、Nd组成则为富含壳源Sr、Nd的流体与幔源基性脉岩不同程度的水—岩反应所致。另外，碳酸盐铅同位素研究显示，下庄矿区成矿物质铀可能来自帽峰式后期流体交代的花岗岩体。 （5）岩石圈伸展与下庄矿田铀成矿有关系密切：下庄矿田铀矿床明显受伸展构造控制，伸展构造既为导矿构造，又为储矿构造；岩石圈伸展导致的地温梯度升高，大地热流平均值加大，驱动热液流体的流动，为铀成矿提供了主要的热驱动力；岩石圈伸展产生的深大断裂导通了壳幔间的联系，使幔源脱气成因挥发份（主要为∑CO2）沿断裂上升，加入壳源热水循环系统，从而参与了铀成矿。 （6）初步建立了下庄矿田“岩石圈伸展体系下大陆热水系统铀矿床成因模式”。模式认为，华南地区白垩—古近纪岩石圈伸展作用引发区内热水流体的大规模循环，且伸展引起的幔源脱气作用产生的挥发份（主要为ΣCO2）加入了贫铀、贫矿化剂的循环的地下热水中，形成了富矿化剂热水。富矿化剂热水从富铀花岗岩中浸出铀（氧化作用），变为富矿化剂、富铀热液流体，这种热液流体在伸展引起的热驱动下沿构造上升，热液流体上升到浅部时，由于地球化学障、流体压力释放等因素的影响，U被还原沉淀，并在有利部位富集成矿。

TabVida: sistema computacional para cálculo de parâmetros biológicos e de crescimento populacional de afídeos.

2010

Estatística aplicada a dados ambientais: influência da qualidade d'água da sub-bacia do Lajeado dos Fragosos sobre a população de borrachudos.

2003

What influences the timing of the introduction of solid food to infants?

The aim of the present study was to assess the factors which may influence the timing of the introduction of solid food to infants. The design was a prospective cohort study by interview and postal questionnaire. Primiparous women (n 541) aged between 16 and 40 years were approached in the Forth Park Maternity Hospital, Fife, Scotland. Of these, 526 women agreed to participate and seventy-eight were used as subjects in the pilot study. At 12 weeks we interviewed 338 women of the study sample. The postal questionnaire was returned by 286 of 448 volunteers. At 12 weeks 133 of 338 mothers said that they had introduced solids. Those that said that they had introduced solids early (<12 weeks) were compared with those who had introduced solids late (>12 weeks) by bivariate and multiple regression analysis. Psychosocial factors influencing the decision were measured with the main outcome measure being the time of introduction of solid food. The early introduction of solids was found to be associated with: the opinions of the infant's maternal grandmother; living in a deprived area; personal disagreement with the advice to wait until the baby was 4 months; lack of encouragement from friends to wait until the baby was 4 months; being in receipt of free samples of manufactured food. Answers to open-ended questions indicated that the early introduction appeared to be influenced by the mothers’ perceptions of the baby's needs. Some of the factors influencing a woman's decision to introduce solids are amenable to change, and these could be targeted in educational interventions.

Effects of prior warm-up regime on severe-intensity cycling performance

Burnley, M, Doust, J and Jones, A (2005) Effects of Prior Warm-up Regime on Severe-Intensity Cycling Performance. Medicine and Science in Sports and Exercise, 37 (5). pp. 838-845. ISSN 1530-0315 RAE2008

Time required for the restoration of normal heavy exercise Vo(2) kinetics following prior heavy exercise

Burnley, M., Doust, J. and Jones, A. (2006). Time required for the restoration of normal heavy exercise Vo(2) kinetics following prior heavy exercise. Journal of Applied Physiology. 101(5), pp.1320-1327 RAE2008

Teatro historico de las Iglesias del Reyno de Aragon : tomo primero preliminar [-IX]

En Tomo V. 2 h. de grabados calcográficos representando monedas de Huesca.

Joyas de diseño contemporáneo elaboradas en oro, plata y otros materiales.

18 fotografías a color.

High-efficiency photovoltaics through mechanically stacked integration of solar cells based on the InP lattice constant

Solar Energy is a clean and abundant energy source that can help reduce reliance on fossil fuels around which questions still persist about their contribution to climate and long-term availability. Monolithic triple-junction solar cells are currently the state of the art photovoltaic devices with champion cell efficiencies exceeding 40%, but their ultimate efficiency is restricted by the current-matching constraint of series-connected cells. The objective of this thesis was to investigate the use of solar cells with lattice constants equal to InP in order to reduce the constraint of current matching in multi-junction solar cells. This was addressed by two approaches: Firstly, the formation of mechanically stacked solar cells (MSSC) was investigated through the addition of separate connections to individual cells that make up a multi-junction device. An electrical and optical modelling approach identified separately connected InGaAs bottom cells stacked under dual-junction GaAs based top cells as a route to high efficiency. An InGaAs solar cell was fabricated on an InP substrate with a measured 1-Sun conversion efficiency of 9.3%. A comparative study of adhesives found benzocyclobutene to be the most suitable for bonding component cells in a mechanically stacked configuration owing to its higher thermal conductivity and refractive index when compared to other candidate adhesives. A flip-chip process was developed to bond single-junction GaAs and InGaAs cells with a measured 4-terminal MSSC efficiency of 25.2% under 1-Sun conditions. Additionally, a novel InAlAs solar cell was identified, which can be used to provide an alternative to the well established GaAs solar cell. As wide bandgap InAlAs solar cells have not been extensively investigated for use in photovoltaics, single-junction cells were fabricated and their properties relevant to PV operation analysed. Minority carrier diffusion lengths in the micrometre range were extracted, confirming InAlAs as a suitable material for use in III-V solar cells, and a 1-Sun conversion efficiency of 6.6% measured for cells with 800 nm thick absorber layers. Given the cost and small diameter of commercially available InP wafers, InGaAs and InAlAs solar cells were fabricated on alternative substrates, namely GaAs. As a first demonstration the lattice constant of a GaAs substrate was graded to InP using an InxGa1-xAs metamorphic buffer layer onto which cells were grown. This was the first demonstration of an InAlAs solar cell on an alternative substrate and an initial step towards fabricating these cells on Si. The results presented offer a route to developing multi-junction solar cell devices based on the InP lattice parameter, thus extending the range of available bandgaps for high efficiency cells.

Decoding an olfactory mechanism of kin recognition and inbreeding avoidance in a primate.

BACKGROUND: Like other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. Although associative, social learning is typically credited for discrimination of familiar kin, discrimination of unfamiliar kin remains unexplained. As sex-biased dispersal in long-lived species cannot consistently prevent encounters between unfamiliar kin, inbreeding remains a threat and mechanisms to avoid it beg explanation. Using a molecular approach that combined analyses of biochemical and microsatellite markers in 17 female and 19 male ring-tailed lemurs (Lemur catta), we describe odor-gene covariance to establish the feasibility of olfactory-mediated kin recognition. RESULTS: Despite derivation from different genital glands, labial and scrotal secretions shared about 170 of their respective 338 and 203 semiochemicals. In addition, these semiochemicals encoded information about genetic relatedness within and between the sexes. Although the sexes showed opposite seasonal patterns in signal complexity, the odor profiles of related individuals (whether same-sex or mixed-sex dyads) converged most strongly in the competitive breeding season. Thus, a strong, mutual olfactory signal of genetic relatedness appeared specifically when such information would be crucial for preventing inbreeding. That weaker signals of genetic relatedness might exist year round could provide a mechanism to explain nepotism between unfamiliar kin. CONCLUSION: We suggest that signal convergence between the sexes may reflect strong selective pressures on kin recognition, whereas signal convergence within the sexes may arise as its by-product or function independently to prevent competition between unfamiliar relatives. The link between an individual's genome and its olfactory signals could be mediated by biosynthetic pathways producing polymorphic semiochemicals or by carrier proteins modifying the individual bouquet of olfactory cues. In conclusion, we unveil a possible olfactory mechanism of kin recognition that has specific relevance to understanding inbreeding avoidance and nepotistic behavior observed in free-ranging primates, and broader relevance to understanding the mechanisms of vertebrate olfactory communication.