攀西地区峨眉山玄武岩的铂族元素地球化学特征

攀西地区龙帚山和二滩玄武岩形成于较低程度地幔部分熔融条件(<7％),部分熔融过程中Ir,Ru和Rh表现其相容性而Pt和Pd为不相容元素．这些样品多含较高的铂族元素(PGE),其Pd／Ir和Cu／Pd比值远高于原始地幔值．部分熔融过程中有少量硫化物(约0．007％)残留于地幔源区,岩浆上升过程中则有部分岩浆达到硫饱和而分离出富集PGE的硫化物(约0．020％～0．033％)．Os,Ir和Pt在结晶分异过程中形成铂族金属合金进入铬铁矿或硫化物,导致Pt和Pd的解耦及Ir含量出现很大变化．玄武质岩浆中熔离出的硫化物可能为邻近喷发通道的镁铁-超镁铁质岩体形成Cu-Ni-PGE矿床(化)提供重要的物质来源．

老挝Boloven高原玄武岩风化壳中稀土元素富集与主量元素关系

老挝南部Champasak省东北部Boloven高原玄武岩喷发于晚中生代．新生代，在长期热带季风型气候和热带季雨林植被条件下，高原玄武岩上已经发育砖红壤型风化壳。在一条风化壳剖面上采集了11件样品并在室内细碎到200目，使用X射线荧光光谱仪分析了11个样品中的主量元素含量，使用ICP-Ms分析了11件样品REE含量。结果表明，玄武岩风化壳中主量元素Na2O和MgO淋失量最大，K2O和CaO淋失量次之，并在淋失一定程度后淋失速度减慢；样品LR157和LR158中TiO2，P2O5分别为6．07％，1．45％和8．43％，0．82％，为整个剖面中的最高值；CaO的含量是松散风化产物中的最高值。风化玄武岩（LR140，LR141）的∑REE较低，为57．8×10^-6和87．9×10^-6；随着玄武岩风化程度和成壤作用的加强，∑REE逐渐富集，并在风化壳表土下（LR157，LR158）达到最高值1003×10^-6和775×10^-6。风化壳中LREE／HREE值为3．59～14．9，稀土元素分布型式属轻稀土富集型。随着风化程度加深，ce由弱负异常逐渐变为强正异常，而Eu由弱正异常逐渐变小并呈现出强负异常，整个剖面中ce正负异常和Eu正负异常的变化幅度较大。REE在剖面中的分布与含TiO2，P2O5的矿物有明显的相关关系，并且在TiO2，P2O5含量最高的样品LR157和LR158中最为富集。REE富集和Ce正异常出现在pH值为5．23～6．12的酸性和Fe^2＋／Fe^3＋为0．007～0．13的氧化环境下，证明在酸性氧化环境也能出现REE富集.

贵州碳酸盐岩红色风化壳稀土富集与分异的机理研究

近期对贵州碳酸盐岩红色风化壳研究发现，碳酸盐岩基岩中稀土含量一般为几十个μg/g，而在岩一土界面附近即E显示超常富集，REE总量最高可达31000μg／g以上，远高于碳酸盐岩基岩和一般风化壳REE含量。同时，稀土富集的部位是剖面底部，而在其它的风化壳中稀上往往在剖面中部即全风化层底部富集。REE超常富集的样品同时伴有Ce的强烈亏损，6Ce值最低为0.007，这也是目前报道过的风化壳中的最低值。另外，风化前缘稀土相对于PAAs标准化后显示MREE富集的特征。弄清碳酸盐岩红色风化壳中稀土富集和分异的机理，有助于丰富稀土表生地球化学知识，同时也为喀斯特地区风化成土地球化学过程和土壤物质来源的示踪提供了重要依据。本文通过对稀土赋存状态的实验研究，结合稀土元素质量迁移系数，系统的分析了稀土元素在碳酸盐岩风化壳中的迁移、转化行为，探讨了稀土发生富集和分异的机理。本次研究取得了如下认识：1、通过对白云岩和灰岩风化壳稀土赋存状态的对比，发现在碳酸盐岩红色风化壳中稀土具有相同的赋存和转化规律。稀土富集层中稀土主要以专性吸附态和残渣态的形式存在，其次是有机质结合态。稀土的赋存状态说明粘土矿物对稀土的吸附是导致稀土在底部超常富集的主要原因。其次，次生稀土磷酸盐矿物，主要是La、Nd等的轻稀土磷酸盐矿物也是稀土富集的主要载体。此外，有机质和铁锰氧化物对稀土的迁移、富集也发挥着重要作用。非富集层主要以 残渣态和铁锰氧化物结合态的形式存在，表明随着风化作用的增强，稀土越易进入稳定的相态中。2、元素质量迁移系数真实的反应了元素的迁入迁出情况。碳酸盐岩的非等体积风化使得稳定的微量元素相对基岩富集，也为风化壳稀土提供了基本的物质来源，但不是导致稀土超常富集的主要原因。稀土元素在风化壳上部表现出很强的活化迁移能力，几乎全部迁出，并且在底部显示明显的带入富集，上部淋漓的稀土为底部稀土的超常富集提供了稳定而充足的物质来源。3、风化壳底部狭窄的碱性障是稀土超常富集的主要制约因素。碳酸盐岩的酸不 溶物含量低，碳酸盐矿物可溶性强，发育程度较高的风化壳剖面能够在垂向上很窄的范围内形成碱性障。7-9的pH值增大了粘土对稀土的吸附量，同时还提高了稀土与各种络阴离子络合的稳定性，有利于稀土沉淀。对于发育完整的碳酸盐岩红色风化壳，介质条件的改变是缓慢的，不能在剖面底部形成碱性障，因此稀土在剖面上部迁出，下部迁入富集，富集层位往往和其它岩类风化壳一样在全风化层的底部。4、经页岩标准化的稀土分布模式在风化前缘显示MREE富集。导致这一现象的原因主要是风化壳中MREE的迁出程度大于HREE和LREE，风化流体显示MREE富集。在底部碱性障条件下，富M咫E的风化流体沉淀、富集。风化流体向下渗透，水岩反应的结果是白云岩也显示M咫E富集，灰岩由于岩一土界面的阻挡，水岩反应深度不大，基岩往往无明显的稀土分异。5、在碳酸盐岩红色风化壳上部Ce显示正异常，底部富集层显示强烈负异常。剖面上部，Ce3＋氧化水解，氧化产物主要与铁锰氧化物共沉淀，少量的与粘土形成氢键或者与有机物络合沉淀，导致剖面上部正异常。Ce在剖面中的迁出量很少，在底部稀土富集层，沉淀富集时主要是La、Pr等LREE，Ce相对贫乏，因此，富集层Ce显示强烈的负异常。与碳酸（氢）根或者磷酸根等络合物形式迁走的Ce很少，不是导致Ce强烈负异常的主要原因。6、基岩性质和良好的水热条件导致碳酸盐岩风化前缘形成特殊的微环境一一碱性障，这是稀土在碳酸盐岩风化壳底部超常富集和分异的主要原因，也是碳酸盐岩红色风化壳稀土行为不同于其它岩类风化壳的主要原因。稀土元素在风化作用过程中发生明显的重组分配，其分布特征不能用以指示物源信息，只能反应风化作用过程信息。

Heat capacity and thermochemical study of trifluoroacetamide (C2H2F3NO)

The low-temperature heat capacities of trifluoroacetamide were precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 404 K. A solid-to-solid phase transition, a fusion and a phase transition from a liquid crystalline phase to fully liquid phase have been observed at the temperatures of 336.911+/-0.102, 347.622+/-0.094 and 388.896+/-0.160 K, respectively. The molar enthalpies of these phase transitions as well as the chemical purity of the substance were determined to be 5.576+/-0.004, 11.496+/-0.007, 1.340+/-0.005 kJ mol(-1) and 99.30 mol%, respectively, on the basis of the heat capacity measurements. The molar entropies of the three phase transitions were calculated to be 16.550+/-0.012, 33.071+/-0.029 and 3.447+/-0.027 J mol(-1) K-1, respectively. Further researches of the thermochemical properties for this compound have been carried out by means of TG and DSC techniques. (C) 2000 Elsevier Science B.V. All rights reserved.

Leveraging Learning and Language Via Communication Bootstrapping

In a Communication Bootstrapping system, peer components with different perceptual worlds invent symbols and syntax based on correlations between their percepts. I propose that Communication Bootstrapping can also be used to acquire functional definitions of words and causal reasoning knowledge. I illustrate this point with several examples, then sketch the architecture of a system in progress which attempts to execute this task.

Controle biológico do mandarová da mandioca Erinnyis ello.

Esta cartilha-guia é entrega de resultado vinculado ao projeto QUINTAL_SAN - Plano de Ação Fitossanidade 06.11.01.007.00.05 - que tem por objetivo servir como guia prático para agricultores familiares visando ao controle biológico aplicado para a lagarta mandarová Erinnyis ello, inseto praga da cultura da mandioca.

Going global in small steps: e-internships in SMEs.

Technological developments over the last thirty years increasingly shaped the means by which we recruit, select and appraise employees. Today, technology supports more flexible and geographically dispersed working modes: From teleworkers, to virtual workers, to e-interns (also known as virtual interns). The current article describes how developments in e-HRM and changes in employment forms contribute to the development and increasing popularity of e-internships (better known as virtual internships) amongst small and medium-sized enterprises. In this paper, we reflect on the rise of e-internships across different countries and relate this to e-HRM and technological advances. We explore the opportunities and challenges. These include developing effective global talent and knowledge management practices, managing diversity as well as intellectual and social capital. We furthermore link the employment of e-internship practices to strategic organizational goals and learning. In the final section, we also critically reflect on the high investment required for e-internships to succeed. The discussion on e-internships is set in the literature on e-HRM, virtual teams and knowledge management, which is furthermore supported by interviews conducted with e-interns or internship managers. Keywords: e-internships, virtual internships, computer-mediated communication

Sole plate fixing details for modern methods of timber construction.

In order to resist lateral loads, modern methods of timber construction are reliant on the in-plane shear strength of the walls orientated parallel to the applied action. In closed panel systems, the shear stresses are transferred to the foundations by the sole plate through the sheathing board, which is usually mechanically jointed to the timber frame. Since closed panels are delivered to site as single units, access to the internal bottom rail is rather restricted and novel, efficient solutions to secure the panel to the substrate are required. Sole plate fixing components for open and closed panel systems were tested in isolation and combination in order to validate a simplistic version of the weakest link theory. As a result, findings were embedded into a software database with a direct link to a previously developed sole plate and racking design application. This integrated process facilitates the structural optimization of the sole plate detail.

Exercise training can induce cardiac autophagy at end-stage chronic conditions: Insights from a graft-versus-host-disease mouse model

Chronic graft-versus-host disease (cGVHD) is a frequent cause of morbimortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and severely compromises patients' physical capacity. Despite the aggressive nature of the disease, aerobic exercise training can positively impact survival as well as clinical and functional parameters. We analyzed potential mechanisms underlying the recently reported cardiac function improvement in an exercise-trained cGVHD murine model receiving lethal total body irradiation and immunosuppressant treatment (Fiuza-Luces et al., 2013. Med Sci Sports Exerc 45, 1703-1711). We hypothesized that a cellular quality-control mechanism that is receiving growing attention in biomedicine, autophagy, was involved in such improvement. Our results suggest that exercise training elicits a positive autophagic adaptation in the myocardium that may help preserve cardiac function even at the end-stage of a devastating disease like cGVHD. These preliminary findings might provide new insights into the cardiac exercise benefits in chronic/debilitating conditions.

Laser-heated high-temperature NMR - a time-resolution study

Submitted to Appl Magn Reson Sponsorship: EPSRC / EU

Rough sets, their extensions and applications

Q. Shen and R. Jensen, 'Rough sets, their extensions and applications,' International Journal of Automation and Computing (IJAC), vol. 4, no. 3, pp. 217-218, 2007.

Rough set feature selection and rule induction for prediction of malignancy degree in brain glioma

X. Wang, J. Yang, R. Jensen and X. Liu, 'Rough Set Feature Selection and Rule Induction for Prediction of Malignancy Degree in Brain Glioma,' Computer Methods and Programs in Biomedicine, vol. 83, no. 2, pp. 147-156, 2006.

Approximation-based feature selection and application for algae population estimation

Q. Shen and R. Jensen, 'Approximation-based feature selection and application for algae population estimation,' Applied Intelligence, vol. 28, no. 2, pp. 167-181, 2008. Sponsorship: EPSRC RONO: EP/E058388/1

Space saving calculation of symbolic resultants

Lloyd, Noel G., and Pearson, Jane M., 'Space saving calculation of symbolic resultants', Mathematics in Computer Science, 1 (2007), 267-290.

Singular perturbation of quantum stochastic differential equations with coupling through an oscillator mode

Gough, John; Van Handel, R., (2007) 'Singular perturbation of quantum stochastic differential equations with coupling through an oscillator mode', Journal of Statistical Physics 127(3) pp.575-607 RAE2008