Assessment of phytostabilization of Pb/Zn mine soils with organic amendments and a native metallicolous ecotype of Festuca Rubra l.: implications for amendment selection and recovery of soil health

La contaminación del suelo es una de las principales amenazas para los ecosistemas y la salud humana. Actualmente, desde un punto de vista tanto económico como ambiental, la fitoestabilización es la mejor tecnología para remediar suelos contaminados con elevadas concentraciones de metales como son los suelos mineros. La fitoestabilización asistida consiste en el empleo de plantas y enmiendas orgánicas y/o inorgánicas con el fin de reducir la movilidad y la biodisponibilidad de los contaminantes y recuperar la salud de suelo. En este trabajo se han realizado ensayos en microcosmos y en campo centrándonos en la salud del suelo minero contaminado con Pb y Zn durante un proceso de fitoestabilización empleando enmiendas orgánicas (purines vacunos, gallinaza, estiércol de oveja y lodos de papelera mezclados con gallinaza) y/o la especie metalífera Festuca rubra con el objetivo de (i) estudiar las interacciones suelo-enmienda responsables de los cambios inducidos por el proceso de quimioestabilización en las propiedades físicoquímicas y biológicas del suelo, (ii) evaluar la efectividad del proceso de fitoestabilización sobre suelos vegetados y de la revegetación sobre suelos desnudos (iii) valorar la idoneidad de distintos indicadores químicos y biológicos (parámetros microbianos y de la vegetación) para monitorizar la efectividad de la fitoestabilización asistida en términos de reducción de la biodisponibilidad de metales en el suelo, mejora de la vegetación y de la recuperación de la salud del suelo. La aplicación de enmiendas al suelo minero supone una entrada de materia orgánica y nutrientes que conduce a una disminución de la biodisponibilidad de metales, facilitando la colonización de las plantas y el crecimiento de la vegetación nativa, además de estimular la actividad microbiana del suelo. El pH del suelo es un factor crítico que condiciona la movilidad de los metales y la toxicidad del suelo. Las poblaciones microbianas de las enmiendas no modificaron la diversidad funcional de las comunidades microbianas nativas de la mina. Los purines vacunos y los lodos de papelera mezclados con gallinaza son los tratamientos más efectivos en el proceso de fitoestabilización asistida bajo condiciones de campo. La gallinaza fue el tratamiento que más estimuló el crecimiento de la vegetación nativa y la colonización en los suelos desnudos. El bioensayo de elongación radical de lechuga es un test sensible, sencillo y barato para evaluar la biodisponibilidad de metal y la ecotoxicidad del suelo. Los tocoferoles son biomarcadores de exposición a metales con potencial para su implementación en bioensayos de toxicidad. Este trabajo permite concluir que la población metalífera de F. rubra, combinada con enmiendas orgánicas, es una excelente candidata para los proyectos de fitoestabilización asistida. Además, la monitorización simultánea de los parámetros fisicoquímicos y microbiológicos del suelo y de su ecotoxicidad permite una evaluación adecuada de la salud del suelo, así como la selección de enmiendas apropiadas para el desarrollo de un proceso fitoestabilizador.

溶胶-凝胶条波导Sagnac环的乙醇蒸气传感特性

采用有机/无机混合溶胶-凝胶法制作条形光波导,并将条波导接入光纤Sagnac 环中,测量了输出光功率随环境气氛中乙醇蒸气体积分数变化的特性,表明在实验研究的范围内,输出信号与乙醇蒸气体积分数呈正弦变化。根据Sagnac环结构输出特性的基本关系,反映了溶胶-凝胶条波导在乙醇蒸气气氛下产生了双折射效应。观察到双折射相移与乙醇体积分数的亚线性关系。对实验数据拟合,计算了偏振相移的线性项和二次项系数,得到所制备的条波导的双折射对乙醇体积分数的响应为Δn≈4.4×10-2。测量了信号变化的时间演变特性,典型的上升和

Active glass-polymer superlattice structure for photonic integration.

We propose an all-laser processing approach allowing controlled growth of organic-inorganic superlattice structures of rare-earth ion doped tellurium-oxide-based glass and optically transparent polydimethyl siloxane (PDMS) polymer; the purpose of which is to illustrate the structural and thermal compatibility of chemically dissimilar materials at the nanometer scale. Superlattice films with interlayer thicknesses as low as 2 nm were grown using pulsed laser deposition (PLD) at low temperatures (100 °C). Planar waveguides were successfully patterned by femtosecond-laser micro-machining for light propagation and efficient Er(3+)-ion amplified spontaneous emission (ASE). The proposed approach to achieve polymer-glass integration will allow the fabrication of efficient and durable polymer optical amplifiers and lossless photonic devices. The all-laser processing approach, discussed further in this paper, permits the growth of films of a multitude of chemically complex and dissimilar materials for a range of optical, thermal, mechanical and biological functions, which otherwise are impossible to integrate via conventional materials processing techniques.

One step self-aligned multilayer patterning process for the fabrication of organic complementary circuits in combination with inkjet printing

Recent development of solution processable organic semiconductors delineates the emergence of a new generation of air-stable, high performance p- and n-type materials. This makes it indeed possible for printed organic complementary circuits (CMOS) to be used in real applications. The main technical bottleneck for organic CMOS to be adopted as the next generation organic integrated circuit is how to deposit and pattern both p- and n-type semiconductor materials with high resolutions at the same time. It represents a significant technical challenge, especially if it can be done for multiple layers without mask alignment. In this paper, we propose a one-step self-aligned fabrication process which allows the deposition and high resolution patterning of functional layers for both p- and n-channel thin film transistors (TFTs) simultaneously. All the dimensional information of the device components is featured on a single imprinting stamp, and the TFT-channel geometry, electrodes with different work functions, p- and n-type semiconductors and effective gate dimensions can all be accurately defined by one-step imprinting and the subsequent pattern transfer process. As an example, we have demonstrated an organic complementary inverter fabricated by 3D imprinting in combination with inkjet printing and the measured electrical characteristics have validated the feasibility of the novel technique. © 2012 Elsevier B.V. All rights reserved.

Biomimetic layer-by-layer assembly of artificial nacre.

Nacre is a technologically remarkable organic-inorganic composite biomaterial. It consists of an ordered multilayer structure of crystalline calcium carbonate platelets separated by porous organic layers. This microstructure exhibits both optical iridescence and mechanical toughness, which transcend those of its constituent components. Replication of nacre is essential for understanding this complex biomineral, and paves the way for tough coatings fabricated from cheap abundant materials. Fabricating a calcitic nacre imitation with biologically similar optical and mechanical properties will likely require following all steps taken in biogenic nacre synthesis. Here we present a route to artificial nacre that mimics the natural layer-by-layer approach to fabricate a hierarchical crystalline multilayer material. Its structure-function relationship was confirmed by nacre-like mechanical properties and striking optical iridescence. Our biomimetic route uses the interplay of polymer-mediated mineral growth, combined with layer-by-layer deposition of porous organic films. This is the first successful attempt to replicate nacre, using CaCO(3).

The effect of organic matter accumulation on phosphorus release in sediment of Chinese shallow lakes

The effects of organic matter in sediment on phosphorus release were studied by field investigations in eight Chinese shallow freshwater lakes with different trophic status and a laboratory experiment. The sediment organic matter content paralleled the trophic status, ranging from 6.1 to 173.0 g kg(-1) (dry weight), with the mean value of 63.1 g kg(-1) (dry weight). It was positively proportional to Soluble reactive phosphorus concentration in the interstitial water in a form of exponential function, but inversely related to the sediment Fe/P ratio. The sediment alkaline phosphatase activity was significantly related not only to the organic matter content (r = 0.829, P < 0.01, n = 120), but also to the soluble reactive phosphorus concentration in interstitial water (r = 0.454, P < 0.01, n = 42). In the laboratory experiment, the addition of organic matter (dry materials of an aquatic macrophyte) into the sediment significantly enhanced alkaline phosphatase activity and soluble reactive phosphorus release. However, in the treatment with organic matter added and aeration, this release was generally prevented in spite of an increase in APA. Hence, sediment organic matter can effectively accelerate phosphorus release by enzymatic hydrolysis and anaerobic desorption. The latter mechanism seems to be more important.

Photovoltaic effect of tin disulfide with nanocrystalline/amorphous blended phases

Tin disulfide (SnS2) nanocrystalline/amorphous blended phases were synthesized by mild chemical reaction. Both X-ray diffraction and transmission electron microscopy measurements demonstrate that the as-synthesized particles presented very small size, with a diameter of only a few nanometers. The photoluminescence (PL) spectrum suggests efficient splitting of photo-generated excitons in poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and SnS2 hybrid films. Organic/inorganic hybrid solar cells comprising MDMO-PPV and SnS2 were prepared, giving photovoltage, photocurrent, fill factor and efficiency values of 0.702 V, 0.549 mA/cm(2), 0.385 and 0.148%, respectively, which suggests that this phase-blended inorganic semiconductor can also serve as a promising solar energy material. (C) 2009 Elsevier Ltd. All rights reserved.

稀土配合物有机／无机杂化薄膜的制备与光电性质研究

有机／无机杂化功能超薄膜是二十一世纪分子科学的重要发展前沿之一，设计具有功能性的有机／无机杂化薄膜已成为这一领域的挑战性课题。本论文分别采用Lallgmuir-B1odgett（LB）膜技术及溶胶一凝胶薄膜组装技术，将稀土无机配合物和稀土有机配合物分别与有机大分子化合物进行薄膜分子组装，对稀土配合物有机／无机杂化薄膜的光、电性质进行了研究。采用LB技术，将K11Ce（PWllO39）2·22H2O，K11Eu（PW11O39）2·25H2O，K11Gd（PW11O39）2·24H2O，K11Sm（PMo11O39）2·19H2O，K11Ce（PMo11O39）2·23H2O，K11Eu（PMo11O39）2·22H2O，K11Gd（PMo11O39）2·2OH2O，K11La（PMo11O39）2·18H2O八种稀土杂多化合物分别掺杂到聚喳琳中，得到十八胺（十八酸）／聚喳琳／稀土杂多化合物导电杂化LB膜。杂化LB膜表面的稀土杂多化合物颗粒大小在30-80nm之间。电性质研究表明，稀土杂多化合物的掺杂可使聚喳琳的导电性显著提高，且钥系稀土杂多化合物掺杂使聚哇琳的导电性增加更为显著。采用溶胶一凝胶薄膜组装技术，将K13（EuSiW11O39）2·28H2O，K13（EuGewl 1039）2·25H2O，K巧（EuBWllO39）2·22H2O，N钩SmWlo036·18H20，Na9DyS10O36·22H2O五种稀土杂多化合物分别与聚醋进行薄膜组装，得到聚醋／稀土杂多化合物溶胶一凝胶膜。荧光光谱研究表明，稀土离子在溶胶一凝胶膜中格位对称性降低，红橙比和黄蓝比发生了改变。1:11型稀土杂多化合物固体与聚酷／稀土杂多化合物溶胶一凝胶膜有不同的能量转移过程，在溶胶一凝胶膜中，配体能将能量传递给稀土离子。采用原位法将对十六烷氧基苯甲酸试及邻十七酞基苯甲酸试有机配合物分别进行了溶胶一凝胶薄膜组装，对其荧光性质进行了研究。结果表明，芳香梭酸配体与稀土诫离子有较好的能级匹配，能够有效地将吸收的能量传递给Tb3+离子，薄膜具有良好的发绿光性能。

[PMMA-b-PAN］-Fe络合物制备有机一无机杂化薄膜

本论文通过聚甲基丙烯酸甲酯-b-聚丙烯睛嵌段共聚物同铁（III）离子络合物（［PMMA-b-PAN］-Fe）制备有机一无机杂化薄膜，并利用妨M对薄膜的表面形态进行了表征。结果表明，通过控制［PMMA-b-PAN］-Fe络合物溶液热处理时间（T=120℃）及络合物溶液中精基同铁＜III）离子的摩尔比率，可以得到不同表面形态的有机一无机杂化薄膜。并借助抑S对［PMMA-b-PAN〕-Fe络合物配位作用进行了研究，发现铁（III）离子与PMMA-b-PAN嵌段共聚物中的睛基配位。此外，对掺杂有FeSO4·7H2O 的均聚甲基丙烯酸甲酷（PMMA）溶液、均聚丙烯睛(PAN)溶液和FeSO4·7H2O（溶解在DMF中）溶液经不同时间热处理（T=120℃）后的薄膜表面形态进行了研究，结果发现，掺杂有FeSO4·7H2O 的PMMA 溶液经20in热处理后，薄膜的表面形态与FeS04·7H2O。溶液经20in热处理后薄膜的表面形态基本相同，而掺杂有FesO4·7H2O的PAN溶液经不同时间热处理后，薄膜的表面形态没有明显的变化。与此同时，对匡[PMMA-b-PAN]-Fe络合物高温热解制备碳材料进行了初步的研究，研究结果表明，利用PMMA-b-PAN］-e杂化薄膜炭化制备具有纳米尺寸孔洞的碳薄膜是可能的，但控制好热解条件至关重要。