简化连续提取法评价污染土壤中Zn、Cd的植物有效性

以0．01mol·L^-1 CaCl2和0．005mol·L^-1 1DTPA作为提取剂，用简化的3步连续提取法对贵州省赫章县土法炼锌污染土壤中Zn、Cd的形态进行了分析．结果显示，污染土壤中Zn、Cd主要以残渣态的形式存在，CaCl2提取态和DTPA提取态Zn、CA平均仅占全量的0．63%、3．91％和lO．94％、10．13％．土壤中不同形态Zn、Cd含量与玉米中Zn、CA含量的相关分析结果显示，CaCl2提取态金属与玉米中金属含量投有显著的相关关系，而DTPA提取态、残渣态以及总量Zn、Cd与玉米根、茎叶中Zn、Cd含量显著正相关．这些结果表明CaCl2提取态Zn、Cd对土壤中该元素的植物有效态可能不具重要贡献，而DTPA提取态金属和金属总量在一定程度上能作为评价土壤中元素植物有效性的标准．

东川桃园式铜矿Ar-Ar同位素年龄及意义

通过对东川桃园铜矿与铜矿共生石英的^40Ar／^39Ar同位素年龄的测定，得到马鞍形年龄谱，其坪年龄为768．43Ma±0．58Ma．等时线年龄为770．00Ma±5．44Ma。该矿床后期改造作用明显，并非同生沉积或成岩作用早期成矿，而与晋宁期Rodina大陆裂解有关。东川铜矿的形成可能是在Rodinia大陆裂解时，从深部带来大量成矿物质改造成岩时期初始的矿化，形成矿床的叠加富集和最终定位．因此，晋宁-澄江期是东川铜矿的主成矿期。

济阳坳陷非烃气藏成因研究－来自气体地球化学和火成岩方解石脉碳氧同位素的证据

济阳坳陷是自三叠纪以来欧亚板块、印度洋板块和库拉－太平洋板块相互作用形成的一个叠置在华北板块上的中、新生代坳陷，位于华北板块东部，东临著名的郯庐大断裂。在坳陷中部的高青－平南断裂地区和西部惠民凹陷发现了大量的CO2气藏，近年来受到很多地质学家和地学工作者的注意。本文在前人资料和自己研究成果的基础上，详细分析了济阳坳陷CO2气藏的气体地球化学特征和惠民凹陷地区火成岩中方解石脉的碳氧同位素特征，为厘定区域内二氧化碳气的来源提供理论依据。通过系统的研究，获得了以下成果和结论： 济阳坳陷CO2气藏中，13CCO2值为-5.67～-3.35‰，主频率段为-4.76～-4.32‰，指示CO2气的主体为无机成因；而气藏中CH4的13C为-54.39～-35.00‰，主频率段为-54.39～-51.55‰，显示以有机成因为主。 济阳坳陷CO2气藏中3He/4He比值为2.80～4.49×10-6，主频率段为3.55～4.49×10-6；40Ar/36Ar值为317～1791，变化较大，主要分布在770～1791；13CCO2值与3He/4He成正相关关系；CO2/3Hem值介于0.769～10.2×109之间，主体为1.86～3.51×109，且CO2/3Hem值与CO2含量一定程度地正相关；CH4/3He比值介于1.01～5.65×108之间，接近于幔源流体值，而远低于壳源特征值，且CH4/3He比值随3He/4He比值减少而增加。以上种种特征都说明，济阳坳陷非烃类气藏中气体具有多来源的特征，但CO2主体是无机成因，并主要来自地幔，少量来自有机成因；在成藏过程，幔源CO2通过转变为CH4或者碳酸盐岩而丢失了部分CO2，壳源CO2和其它烃类加入到气藏中；花沟地区的气体地球化学特征与众不同，可能存在碳酸盐地层变质脱气产生的CO2的混入，但具体原因尚待进一步研究。 济阳坳陷惠民凹陷地区火成岩中方解石脉的碳同位素数据-3.30～3.14‰，氧同位素数据12.64～16.97‰，二者成正相关关系，同时也位于前人所说的沉积混染趋势线上，具有较为典型的壳幔混合特征。这些方解石脉的碳同位素又明显的位于海相碳酸盐岩范围之内，说明脉体的主要碳源不是深源的，而是来自于海相底层。

滇西新生代富碱火成岩及其与金成矿关系研究-以北衙金矿为例

本论文在前人数据资料和研究成果的基础上，以北衙金矿床及其相关的富碱侵入岩作为主要研究对象，以探讨滇西新生代富碱火成岩成岩过程及富碱岩浆上升演化过程中的流体分异，北衙金矿床的成因，最终揭示北衙金矿床与相关的富碱侵入岩之间的关系为主要研究目的，通过主、微量（包括稀土）元素地球化学，Pb、Sr、Nd、C、O、S及He-Ar等同位素地球化学，以及流体包裹体地球化学等方面的研究获得以下主要认识：-1．滇西新生代富碱火成岩来源于EM-II型富集地慢，源区的交代富集过程与古特提斯洋壳的俯冲有关，俯冲板片的含水流体对上覆上慢楔的交代是滇西富碱侵入岩（相当于A型花岗岩）含水的原因，这次富碱岩浆活动是一次滞后的弧岩浆活动；富碱中、酸性岩浆由碱性玄武质岩浆混染约20％的主要来自变质基底的地壳物质演化而来；滇西新生代富碱岩浆具备岛弧岩浆的氧化条件（即fogfo2＞FMQ＋2，FMQ代表铁橄榄石一磁铁矿一石英氧缓冲），并在其上升演化过程中分异出大量的流体相，具有较大的An、Cu成矿潜力。2．北衙金矿的矿化时代33.0±1.5Ma与相关的富碱侵入岩的成岩时代（32-34Ma）一致。3，成矿早期流体或初始流体具有富碱岩浆在变质基底内分异的流体的Nd和sr同位素组成（Isr≈0.722390，ε Nd（t）≈-2.8）、矿区及外围富碱斑岩的平均Pb同位素组成（206Pb／204Pb＝18.590，207Pb／204Pb=15.606，208Pb／204Pb＝38.770）、与相关富碱斑岩一致的稀土配分模式、岩浆热液的C、O同位素组成（δ13C≈-5％0，61、尧11％0）、以及壳一慢混合He－Ar同位素组成（3He尸He；1 ．80-1．94 Ra，3He／3 6Ar＝1 ．19 * 10-3-3．93火10·3）并显示明显的He-Ar分异（4oAr*/He＝0．34-0．75），且以高温、高压、高盐度、富c02为特征，说明初始流体主要在变质基底内由富碱岩浆分异而来；初始流体在上升过程中由于温度、压力降低发生富co2相和盐水相的分离，成矿元素优先分配进入富COZ相，逐步演化为成矿阶段流体；成矿阶段流体在去气或与大气降水混合过程中释放出其中的成矿元素。4．约80％的成矿金属来自富碱岩浆，其余部分主要通过岩浆流体从变质基底摄取。结论：北衙金矿与相关的富碱侵入岩具有密切的成因关系。

水库对乌江河流汞生物地球化学循环的影响

本论文的主要研究内容有以下三个方面：（1）蒸馏一乙基化GC-CVAFS法测定天然水体中甲基汞方法的建立及应用；（2）乌江表层河水不同形态汞分布特征的研究；（3）以乌江中上游干流不同年龄水库（乌江渡水库和东风水库）为例，探讨水库对乌江河流汞输送的影响及水库内汞的迁移转化。通过本论文的研究，取得以下成果：1．建立了一种基于蒸馏一乙基化结合气相色谱（GC）一冷原子荧光（CVAFS）测定天然水体中甲基汞的分析方法。水样中甲基汞经蒸馏后与四乙基硼化钠反应生成挥发性的甲基乙基汞，由氮气吹扫捕集于Tenax管，然后由GC-CVAFS测定。该方法的回收率为88.2％-108.4％，平均相对标准偏差为5．4％。取45mL水样测定，方法的最低检出限为0.009ng/L。该方法能准确测定天然水体中甲基汞的含量，步骤简洁、快速，明显优于国内目前使用的其余测定水体甲基汞的方法。2．乌江表层河水总汞的浓度分别为：丰水期659ng/L，枯水期16.9ng/L，明显高于北美和欧洲一些没受污染的河流，表明乌江流域已存在一定程度的污染。乌江河水汞的主要形态为颗粒态汞，其占总汞的比例为丰水期84％，枯水期占52％，乌江河流汞的分布、迁移行为主要受颗粒态物质控制。3．根据输入一输出通量模型，估算出东风水库总汞净通量为-57785.1g/yr，占总汞输入量的40.2％；乌江渡水库总汞净通量为-23273.7g/yr，占总汞输入量的14.0％，两个水库都表现为总汞的“汇”。与总汞相反，两个水库都表现为甲基汞的“源”，东风水库甲基汞净通量为+284.7g/yr，占甲基汞总输入量的4.4％；乌江渡水库甲基汞的净通量为＋6622.0g/yr，占甲基汞总输入量的80.1％。乌江渡水库甲基汞的“源”作用显著大于东风水库。4．乌江渡水库和东风水库水体总汞和甲基汞都呈现明显的季节变化，表现为春季＞冬季、夏季。乌江渡水库水体总汞平均为冬季9.0ng/L、春季16.0ng/L、夏季7.9ng/L；东风水库水体总汞平均为冬季8.2ng/L、春季12.5ng/L、夏季9.4ng/L。水体甲基汞的平均值分别为：乌江渡水库冬季0.74ng/L、春季0.97ng/L夏季0．89ng/L；东风水库冬季0.74ng/L、春季1.12ng/L、夏季0.38ng/L。水库水体甲基汞与总汞之间有相关关系，但未达极显著水平（乌江渡水库，r=0.451*，n=24；东风水库，r=0.471*，n＝27）。水库内汞和甲基汞的形态、含量以及分布受外源性输入、降水稀释、水库初级生产力水平以及水库运行方式等因素控制。5．乌江渡水库和东风水库沉积物总汞明显高于其它未受污染地区水库沉积物总汞。乌江渡水库沉积物总汞含量为254.7±44.3ng/g，东风水库沉积物总汞为171.0±23.0ng/g。两个水库沉积物总汞没有季节变化，且在沉积物垂直剖面上也没有明显的浓度梯度变化。与总汞相反，两个水库沉积物甲基汞在垂直剖面上有明显的梯度变化和季节变化。无机汞的甲基化作用主要发生在沉积物表层5cm以内。沉积物中甲基汞含量受微生物活性影响显著，通常在水库生物生产量和营养物输入量较大时甲基汞浓度也较高。沉积物甲基汞含量在两个水库都表现为冬季＜春季＜夏季，甲基汞含量以及甲基汞占总汞的比例为东风水库＜乌江渡水库。6．沉积物间隙水中无机汞的含量没有显著的季节变化；与此相反，沉积物间隙水中甲基汞浓度表现出明显的季节变化。沉积物间隙水中甲基汞在垂直剖面上的分布趋势与沉积物中甲基汞的分布趋势相一致，沉积物间隙水中甲基汞含量与沉积物中甲基汞含量呈显著性相关（乌江渡水库，r=0.770**，n＝75；东风水库，r＝0.675**,n＝75）。7．沉积物间隙水中无机汞和甲基汞是水体中无机汞和甲基汞的“源，，i但对乌江渡水库和东风水库而言，由于水体深度较大，水力停留时间较短，间隙水中扩散出来的甲基汞和无机汞对水库内水体中相应形态汞含量的影响程度有限。但这种影响作用为甲基汞＞无机汞，乌江渡水库＞东风水库。8．因采集的鱼多为人工饲养鱼（生长速度快、食物链短），两个水库鱼体总汞和甲基汞含量均低于国家食用标准。但乌江渡水库鱼体甲基汞含量以及甲基汞占总汞的比例均高于东风水库。可见，乌江流域水库鱼体甲基汞含量不取决于水库年龄，而受水库内水生食物链底端食物中甲基汞的含量控制。9．通过本论文的研究，得出由于被淹没土壤有机质含量较低，乌江流域水库无机汞甲基化的驱动力为水库内源性输入有机质。在一定的时间范围内，随着水库的发育，水库初级生产力水平的提高，内源性有机质输入量增加，会显著促进沉积物中无机汞的甲基化进程。

Diagnóstico ambiental do Município de Iguaraci, PE.

O municipio de Iguaraci, com uma area de 770,96 km2, localiza-se na regiao semi-arida de Pernambuco, na Zona do Alto Pajeu. O estudo, na escala 1:100.000, identifica os diversos ambientes do municipio, com suas principais vocacoes, potencialidades e limitacoes. Pode, entao, subsidiar o planejamento de atividades agricolas, pecuarias, florestais ou outros tipos de atividades nao agricolas, incluindo recomendacoes de areas para preservacao ambiental. O municipio foi dividido em 15 segmentos geoambientais em funcao do arranjo e distribuicao dos diferentes solos em topossequencias, do grau xerofitico da caatinga (hiper e hipoxerofila) e, no caso das Serras e Serrotes, tambem foram consideradas suas dimensoes e diferencas geologicas. Estes segmentos geoambientais foram agrupados em 5 subunidades geoambientais em funcao de diferenciacoes geologicas, aspectos morfoestruturais, e de combinacoes de caracteristicas de geologia e relevo. As subunidades geoambientais identificadas foram as seguintes: (1) Tabuleiros Interioranos Dissecados Isolados - TD (com o segmento geoambiental TD1); (2) Superficies Avermelhadas do Cristalino - SA (com o segmento geoambiental SA1); (3) Pediplanos do Alto Pajeu - PD (com os segmentos geoambientais PD1 a PD6); (4) Terracos Aluviais - Baixios - TA (com os segmentos geoambientais TA1 e TA2); e (5) Serras, Serrotes e Elevacoes Residuais - SS (com os segmentos geoambientais SS1 a SS5). Os segmentos geoambientais indicados preferencialmente para lavouras sao TD1, SA1, TA1, TA2, PD1 e PD2, que perfazem uma area de 76,48 km2. Os segmentos indicados para lavouras e/ou pastagens (plantadas ou naturais) sao PD3 e PD4, abrangendo uma area de 206,74 km2. Os segmentos geoambientais recomendados para pecuaria extensiva, pastagem natural e/ou plantada e apicultura, sao PD5 e PD6, perfazendo uma area de 359,56 km2. Os segmentos indicados para preservacao ambiental sao os SS1 a SS5, perfazendo uma area de 18,18 km2.

Estudo da prevalência da discrepância anterior de Bolton numa população ortodôntica portuguesa

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária

Old Spain in new America , by Robert McLean ... and Grace Petrie Williams ... Issued by the Council of women for home mission.

http://www.archive.org/details/oldspaininnewame00mcleiala

Tissue-engineered cardiac patch for advanced functional maturation of human ESC-derived cardiomyocytes.

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) provide a promising source for cell therapy and drug screening. Several high-yield protocols exist for hESC-CM production; however, methods to significantly advance hESC-CM maturation are still lacking. Building on our previous experience with mouse ESC-CMs, we investigated the effects of 3-dimensional (3D) tissue-engineered culture environment and cardiomyocyte purity on structural and functional maturation of hESC-CMs. 2D monolayer and 3D fibrin-based cardiac patch cultures were generated using dissociated cells from differentiated Hes2 embryoid bodies containing varying percentage (48-90%) of CD172a (SIRPA)-positive cardiomyocytes. hESC-CMs within the patch were aligned uniformly by locally controlling the direction of passive tension. Compared to hESC-CMs in age (2 weeks) and purity (48-65%) matched 2D monolayers, hESC-CMs in 3D patches exhibited significantly higher conduction velocities (CVs), longer sarcomeres (2.09 ± 0.02 vs. 1.77 ± 0.01 μm), and enhanced expression of genes involved in cardiac contractile function, including cTnT, αMHC, CASQ2 and SERCA2. The CVs in cardiac patches increased with cardiomyocyte purity, reaching 25.1 cm/s in patches constructed with 90% hESC-CMs. Maximum contractile force amplitudes and active stresses of cardiac patches averaged to 3.0 ± 1.1 mN and 11.8 ± 4.5 mN/mm(2), respectively. Moreover, contractile force per input cardiomyocyte averaged to 5.7 ± 1.1 nN/cell and showed a negative correlation with hESC-CM purity. Finally, patches exhibited significant positive inotropy with isoproterenol administration (1.7 ± 0.3-fold force increase, EC50 = 95.1 nm). These results demonstrate highly advanced levels of hESC-CM maturation after 2 weeks of 3D cardiac patch culture and carry important implications for future drug development and cell therapy studies.

Hacer atractivo el aprendizaje de la matemática, insertando los contenidos dentro de modelos reales

Diversos estudios sobre tecnologías educativas para la docencia superior, formulan la participación activa y aprendizajes significativos, complementado con trabajo interactivo y autoestima positiva. Investigadores en educación afirman que “Construimos significados cuando relacionamos las nuevas informaciones con nuestros esquemas previos de comprensión de la realidad”. Por tanto, se propone incluir los contenidos dentro de situaciones naturales que impliquen el enfrentamiento del alumno con tareas que se asemejen a las complejas situaciones de la vida real y profesional. Esto apoyado con tecnología, donde el objetivo sea desarrollar actividades que permitan al alumno descubrir relaciones, propiedades, y donde desarrolle la capacidad de análisis, creatividad y una actitud crítica hacia los resultados.

No-flow underfill flip chip assembly–an experimental and modeling analysis

In the flip-chip assembly process, no-flow underfill materials have a particular advantage over traditional underfill: the application and curing of the former can be undertaken before and during the reflow process. This advantage can be exploited to increase the flip-chip manufacturing throughput. However, adopting a no-flow underfill process may introduce reliability issues such as underfill entrapment, delamination at interfaces between underfill and other materials, and lower solder joint fatigue life. This paper presents an analysis on the assembly and the reliability of flip-chips with no-flow underfill. The methodology adopted in the work is a combination of experimental and computer-modeling methods. Two types of no-flow underfill materials have been used for the flip chips. The samples have been inspected with X-ray and scanning acoustic microscope inspection systems to find voids and other defects. Eleven samples for each type of underfill material have been subjected to thermal shock test and the number of cycles to failure for these flip chips have been found. In the computer modeling part of the work, a comprehensive parametric study has provided details on the relationship between the material properties and reliability, and on how underfill entrapment may affect the thermal–mechanical fatigue life of flip chips with no-flow underfill.

Shear strength analysis of ball grid array (BGA) solder interfaces

Ball shear test is the most common test method used to assess the reliability of bond strength for ball grid array (BGA) packages. In this work, a combined experimental and numerical study was carried out to realize of BGA solder interface strength. Solder mask defined bond pads on the BGA substrate were used for BGA ball bonding. Different bond pad metallizations and solder alloys were used. Solid state aging at 150degC up to 1000 h has been carried out to change the interfacial microstructure. Cross-sectional studies of the solder-to-bond pad interfaces was conducted by scanning electron microscopy (SEM) equipped with an energy dispersive X-ray (EDX) analyzer to investigate the interfacial reaction phenomena. Ball shear tests have been carried out to obtain the mechanical strength of the solder joints and to correlate shear behaviour with the interfacial reaction products. An attempt has been taken to realize experimental findings by Finite Element Analysis (FEA). It was found that intermetallic compound (IMC) formation at the solder interface plays an important role in the BGA solder bond strength. By changing the morphology and the microchemistry of IMCs, the fracture propagation path could be changed and hence, reliability could be improved

Partners moving freely

Examines the provisions of European Parliament and Council Directive 2004/38 protecting the rights of EU citizens' partners to move freely within the EU. Highlights criticisms of the previous legislation, in particular, the lack of rights for cohabitees. Considers the extension of rights to registered partners, and the improved position of unmarried partners, noting, however, the lack of guidance on whether an unmarried couple's relationship is "durable" and "duly attested". Explains the circumstances in which non-EU spouses will not now lose the right of residence on divorce. [From Legal Journals Index]

Laser Doppler velocimetry measurements of particle velocity profiles in gas-solid two-phase flows

The measurement of particle velocities in two-phase gas-solid systems has a wide application in flow monitoring in process plant, where two-phase gas-solids systems are frequently employed in the form of pneumatic conveyors and solid fuel injection systems. Such measurements have proved to be difficult to make reliably in industrial environments. This paper details particle velocity measurements made in a two phase gas-solid now utilising a laser Doppler velocimetry system. Tests were carried out using both wheat flour and pulverised coal as the solids phase, with air being used as the gaseous phase throughout. A pipeline of circular section, having a diameter of 53 mm was used for the test work, with air velocities ranging from 25 to 45 m/s and suspension densities ranging from 0.001 kg to 1 kg of solids per cubic meter of air. Details of both the test equipment used, and the results of the measurements are presented.