224 resultados para MAA


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I discuss role responsibly, individual responsibility and collective responsibility in corporate multinational setting. My case study is about minerals used in electronics that come from the Democratic Republic of Congo. What I try to show throughout the thesis is how many things need to be taken into consideration when we discuss the responsibility of individuals in corporations. No easy and simple answers are available. Instead, we must keep in mind the complexity of the situation at all times, judging cases on individual basis, emphasizing the importance of individual judgement and virtue, as well as the responsibility we all share as members of groups and the wider society. I begin by discussing the demands that are placed on us as employees. There is always a potential for a conflict between our different roles and also the wider demands placed on us. Role demands are usually much more specific than the wider question of how we should act as human beings. The terminology of roles can also be misleading as it can create illusions about our work selves being somehow radically separated from our everyday, true selves. The nature of collective decision-making and its implications for responsibility is important too. When discussing the moral responsibility of an employee in a corporate setting, one must take into account arguments from individual and collective responsibility, as well as role ethics. Individual responsibility is not a separate or competing notion from that of collective responsibility. Rather, the two are interlinked. Individuals' responsibilities in collective settings combine both individual responsibility and collective responsibility (which is different from aggregate individual responsibility). In the majority of cases, both will apply in various degrees. Some members might have individual responsibility in addition to the collective responsibility, while others just the collective responsibility. There are also times when no-one bears individual moral responsibility but the members are still responsible for the collective part. My intuition is that collective moral responsibility is strongly linked to the way the collective setting affects individual judgements and moulds the decisions, and how the individuals use the collective setting to further their own ends. Individuals remain the moral agents but responsibility is collective if the actions in question are collective in character. I also explore the impacts of bureaucratic ethic and its influence on the individual. Bureaucracies can compartmentalize work to such a degree that individual human action is reduced to mere behaviour. Responsibility is diffused and the people working in the bureaucracy can come to view their actions to be outside the normal human realm where they would be responsible for what they do. Language games and rules, anonymity, internal power struggles, and the fragmentation of information are just some of the reasons responsibility and morality can get blurry in big institutional settings. Throughout the thesis I defend the following theses: ● People act differently depending on their roles. This is necessary for our society to function, but the more specific role demands should always be kept in check by the wider requirements of being a good human being. ● Acts in corporations (and other large collectives) are not reducible to individual actions, and cannot be explained fully by the behaviour of individual employees. ● Individuals are responsible for the actions that they undertake in the collective as role occupiers and are very rarely off the hook. Hiding behind role demands is usually only an excuse and shows a lack of virtue. ● Individuals in roles can be responsible even when the collective is not. This depends on if the act they performed was corporate in nature or not. ● Bureaucratic structure affects individual thinking and is not always a healthy environment to work in. ● Individual members can share responsibility with the collective and our share of the collective responsibility is strongly linked to our relations. ● Corporations and other collectives can be responsible for harm even when no individual is at fault. The structure and the policies of the collective are crucial. ● Socialization plays an important role in our morality at both work and outside it. We are all responsible for the kind of moral context we create. ● When accepting a role or a position in a collective, we are attaching ourselves with the values of that collective. ● Ethical theories should put more emphasis on good judgement and decision-making instead of vague generalisations. My conclusion is that the individual person is always in the centre when it comes to responsibility, and not so easily off the hook as we sometimes think. What we do, and especially who we choose to associate ourselves with, does matter and we should be more careful when we choose who we work for. Individuals within corporations are responsible for choosing that the corporation they associate with is one that they can ascribe to morally, if not fully, then at least for the most part. Individuals are also inclusively responsible to a varying degree for the collective activities they contribute to, even in overdetermined contexts. We all are responsible for the kind of corporations we choose to support through our actions as consumers, investors and citizens.

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Euroopan unionin liikennepolitiikan yhtenä tavoitteena on vähentää tieliikenteen ulkoisvaikutuksia, joita ovat esimerkiksi ruuhkat, saasteet, melu ja liikenneonnettomuudet. Keinona Euroopan unioni esittää tieliikenteen hinnoittelujärjestelmien tehostamista ja ulkoisvaikutusten kustannusten ohjaamista niiden aiheuttajien maksettavaksi. Tavoitteena on siirtyä ajoneuvojen hankinnan ja omistamisen verottamisesta kohti liikkumisen ja tienkäytön veroja ja maksuja. Pitkän aikavälin kehityssuunta on kohti rajakustannushinnoittelua, joka voidaan toteuttaa esimerkiksi GPS paikannukseen perustuvalla kansallisella kilometriperusteisella tienkäyttömaksulla. Tieliikenteen käyttäjät maksaisivat ajettujen kilometrien mukaan ja kilometrille kohdistuvaa maksua voitaisiin vaihdella esimerkiksi paikan, ajan ja ajoneuvon ominaisuuksien mukaan. Taloustieteen mukaan Euroopan unionin tavoite tieliikenteen rajakustannushinnoittelusta on järkevä ja johtaisi tehokkaaseen resurssien allokaatioon. Euroopan unionin linjaukset noudattavat yleisempää kansainvälistä kehityssuuntaa. Suomi on Baltian maiden ohella ainoa Manner-Euroopan maa, jossa ei ole käytössä minkäänlaisia tienkäyttömaksuja. Vaikka Suomen tieliikenteen verotus on kansainvälisesti korkea, sen rakenne kaipaa uudistamista. Suomen verotuksen painopiste on omistamisen verottamisessa ja nykyisen verotuksen ohjaavuusvaikutukset ovat rajalliset. Etenkin polttoaineverotukselle lisähaasteita tuovat ajoneuvojen uudet energialähteet ja entistä matalampi polttoaineen kulutus. Vaikka teknologia kehittyy, autoilla tulee edelleen olemaan yhteisiä ominaisuuksia - ne tarvitsevat väylätilaa liikkumiseen ja parkkitilaa säilytykseen. Tutkin tässä työssä Suomen nykyisen tieliikenteen verotuksen korvaamista kansallisella kilometriperusteisella tienkäyttömaksulla. Uudistus parantaisi tieliikennemarkkinoiden tehokkuutta, mutta parantaisiko se myös oikeudenmukaisuutta? Yksi isoimmista huolenaiheista mitä tahansa uutta hinnoittelu- tai verouudistusta suunniteltaessa on hyväksyttävyys ja siten oikeudenmukaisuus. Työssäni havaitsen, että Suomen nykyinen tieliikenteen verotus ei ole tehokas eikä monelta osin oikeudenmukainen. Verouudistukset kohtaavat usein kiivasta vastustusta ja etenkin tienkäyttömaksuille hyväksyttävyys on ongelma. Uudistuksista keskusteltaessa on myös tärkeää tutkia mitä ollaan uudistamassa. Millaisia hyvinvointivaikutuksia vallitsevalla järjestelmällä on? Myös nykyinen järjestelmä on arvovalinta, jonka oikeudenmukaisuutta on aika-ajoin syytä tarkastella.

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Metsäteollisuudesta kertyy vuosittain suuria määriä ylijäämämateriaalia, kuten puun kuorta ja oksia.Ylimääräinen aines käytetään pääasiassa energiantuotantoon, mutta uusia soveltamismahdollisuuksia kaivataan. Kuoren on havaittu olevan potentiaalinen lähde monille bioaktiivisille yhdisteille, joille olisi käyttöä esimerkiksi lääke- ja kemianteollisuudessa sekä maa-, metsä- ja puutarhatuotannon tuholaistorjunnassa. Tutkimus on osa Euroopan Unionin rahoittamaa ForestSpeCs-projektia, jonka tarkoituksena on selvittää metsäteollisuuden ylijäämämateriaalien vaihtoehtoisia käyttötapoja. Valittujen kymmenen teollisesti merkittävän pohjoisen puulajin (Abies nephrolepis, Betula pendula, Larix decidua, L. gmelinii, L. sibirica, Picea abies, P. ajanensis, P. pumila, Pinus sylvestris, Populus tremula) kuoresta uutettujen aineiden soveltuvuutta syönninestoaineeksi testattiin kaaliperhosen (Pieris brassicae L.) ja krysanteemiyökkösen (Spodoptera littoralis Boisduval) toukilla sekä osittain sinappikuoriaisella (Phaedon cochloreae Fabricius) ja idänlehtikuoriaisella (Agelastica alni L.). Uutteet valmistettiin yhteistyössä projektin ryhmien avulla tai itsenäisesti erilaisin menetelmin. Testaukset tehtiin laboratorio-oloissa käyttäen lehtikiekkojen valintabiotestiä sekä karkeilla uutteilla että niistä erotelluilla yksittäisillä yhdisteillä. Tehdyistä mittauksista laskettiin syönninestoindeksit (FDI). Tulosten perusteella lähes kaikki testatut uutteet vaikuttivat ainakin jossain määrin kohdehyönteisen syöntikäyttäytymiseen. Hieman yli puolet kaaliperhosella testatuista 46 uutteesta aiheuttivat yli 50 % syönnineston eli kaaliperhonen suosi kontrollilehtiä uutteella käsiteltyjä todennäköisemmin. Krysanteemiyökkösellä yli 50 %:n syönnineston aiheuttivat vain seitsemän testatuista 56 uutteesta. Lisäksi kolme uutetta lisäsi käsiteltyjen kiekkojen syöntiä merkittävästi. Idänlehtikuoriaistoukat ja -aikuiset karttoivat erityisesti abietiinihapolla käsiteltyjä lehtiä. Sinappikuoriaisella testatut uutteet toimivat myös lupaavasti. Testattujen puulajien kuoresta on mahdollista uuttaa biologisesti aktiivisia yhdisteitä, mutta tuholaistorjunnan kannalta oikeiden pitoisuuksien ja tehokkaiden uuttomenetelmien löytäminen vaatii jatkotutkimuksia. Kuoren sisältämien yhdisteiden laatu ja määrä vaihtelevat monien tekijöiden, kuten ympäristön ja genetiikan vaikutuksesta. Hyönteisten sietokyky vaihtelee myös paljon lajeittain ja yksilöidenkin välillä on eroja. Uutteista valmistettavia torjunta-aineita olisi kuitenkin mahdollista sisällyttää esimerkiksi integroituun torjuntaan muiden menetelmien rinnalle tulevaisuudessa.

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Soil is an unrenewable natural resource under increasing anthropogenic pressure. One of the main threats to soils, compromising their ability to provide us with the goods and ecosystem services we expect, is pollution. Oil hydrocarbons are the most common soil contaminants, and they disturb not just the biota but also the physicochemical properties of soils. Indigenous soil micro-organisms respond rapidly to changes in the soil ecosystem, and are chronically in direct contact with the hydrophobic pollutants on the soil surfaces. Soil microbial variables could thus serve as an intrinsically relevant indicator of soil quality, to be used in the ecological risk assessment of contaminated and remediated soils. Two contrasting studies were designed to investigate soil microbial ecological responses to hydrocarbons, together with parallel changes in soil physicochemical and ecotoxicological properties. The aim was to identify quantitative or qualitative microbiological variables that would be practicable and broadly applicable for the assessment of the quality and restoration of oil-polluted soil. Soil bacteria commonly react on hydrocarbons as a beneficial substrate, which lead to a positive response in the classical microbiological soil quality indicators; negative impacts were accurately reflected only after severe contamination. Hydrocarbon contaminants become less bioavailable due to weathering processes, and their potentially toxic effects decrease faster than the total concentration. Indigenous hydrocarbon degrader bacteria, naturally present in any terrestrial environment, use specific mechanisms to improve access to the hydrocarbon molecules adsorbed on soil surfaces. Thus when contaminants are unavailable even to the specialised degraders, they should pose no hazard to other biota either. Change in the ratio of hydrocarbon degrader numbers to total microbes was detected to predictably indicate pollutant effects and bioavailability. Also bacterial diversity, a qualitative community characteristic, decreased as a response to hydrocarbons. Stabilisation of community evenness, and community structure that reflected clean reference soil, indicated community recovery. If long-term temporal monitoring is difficult and appropriate clean reference soil unavailable, such comparison could possibly be based on DNA-based community analysis, reflecting past+present, and RNA-based community analysis, showing exclusively present conditions. Microbial ecological indicators cannot replace chemical oil analyses, but they are theoretically relevant and operationally practicable additional tools for ecological risk assessment. As such, they can guide ecologically informed and sustainable ecosophisticated management of oil-contaminated lands.

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La División de Zoología de Vertebrados de la Facultad de Ciencias Naturales de la Universidad Nacional de La Plata y la Secretaria de Ambiente y Desarrollo Sustentable de la Nación a través de su Proyecto Marino Patagónico, han tomado esta responsabilidad con el convencimiento de la necesidad de contar con nuevos escenarios para el encuentro de profesionales de la especialidad. El intercambio de experiencias desde las distintas especialidades, el reconocimiento de las fortalezas y debilidades para el desarrollo de proyectos, el intercambio de ideas sobre los vacíos de información y la disponibilidad de recursos financieros, constituyen algunos de los elementos esenciales para el fortalecimiento de la investigación y el desarrollo tecnológico nacional y regional. (PDF tiene 28 paginas.)

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Neste trabalho foi feito um estudo sobre a preparação e caracterização de microesferas poliméricas à base de poli(ácido metacrílico-co-divinilbenzeno) por polimerização por precipitação. As partículas foram sintetizadas e analisadas em diferentes condições de reação. Partículas esféricas políméricas foram sintetizadas na faixa de 1,66 - 8,41 m, assim como partículas no estado de microgel. As partículas foram caracterizadas pelas técnicas de espalhamento de luz dinâmica (DLS), análise termogravimétrica (TGA), espectroscopia na região do infravermelho (FTIR), adsorção de nitrogênio pelos métodos BET (Brunauer, Emmett e Teller) e BJH (Barret, Joyner e Halenda), microscopia ótica, microscopia eletrônica de varredura, e testes de razão de inchamento. A análise das partículas foi feita para verificar a influência da mudança na composição de comonômeros, grau de reticulação, relação de monômeros totais/diluentes em massa/volume (g/100 mL), e quanto à relação volumétrica de diluentes. Verificou-se que houve um aumento no tamanho das partículas e da resistência térmica com a diminuição da fração molar de MAA (ácido metacrílico). Na preparação de partículas com fração molar de 50% de MAA, e relação volumétrica acetonitrila/tolueno de 75/25, quanto maior a relação de monômeros totais/diluentes (g/100 mL), maior o tamanho e o rendimento das partículas. Com a mudança da relação volumétrica de diluentes, houve mudança nas características de porosidade, tamanho das partículas, e grau de inchamento das partículas, sendo que na relação volumétrica acetonitrila/tolueno de 50/50, houve formação de microgel

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< p > The past population dynamics of four domestic and one wild species of bovine were estimated using Bayesian skyline plots, a coalescent Markov chain Monte Carlo method that does not require an assumed parametric model of demographic history. Four dom

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To evaluate the benthic diversity of River Gomti in relation to the prevailing environmental conditions, four stations, viz., Maa Chandrika Devi, Daliganj, Ambedkar Park and Aquaduct, were identified from upstream to downstream along the course of the river in Lucknow. Dissolved oxygen was low on many occasions at all the stations except Maa Chandrika Devi and chemical oxygen demand values were high. There was a gradual increase in mean nitrite and phosphate values from up to downstream. Benthic fauna was dominated by oligochaetes and chironomus larvae. Other groups reported were leeches, nematodes, sponges, crustaceans, pelycypodes, gastropods and fish fry. Population density was exceptionally high at Daliganj (20,135 m sub(-1) ) followed by Ambedkar Park (5,199 m sub(-1)) and Aquaduct (3,287 m sub(-1)), and low at Maa Chandrika Devi (264 m sub(-1)). Oligochaete genera common at all the four stations were Lumbricillus, Limnodrillus, Branchiura, Chaetogaster, Nais and Tubifex. Odonates were reported only from Maa Chandrika Devi while sponges were encountered at Daliganj and Aquaduct. On some occasions, fish fry were also found at Ambedkar Park and Aquaduct. Seasonally, maxima for population density were observed during pre-monsoon and minima during monsoon. The organic pollution indicator benthic species reported were tubificids, chironomids, culicoid larvae, Lamellidens sp., Corbicula sp., Lymnaea sp. and leech. Branchiurans, Tubifex sp. and Chironomus larvae were reported at all the stations. Filthy condition with foul smell throughout the length of the river coupled with poor water quality and appearance of indicator organisms at all the stations indicate that the river is under severe pollution stress due to anthropogenic discharges and it has reached an alarming stage.

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A new method to fabricate nanoscale metallic air-bridges has been investigated. The pillar patterns of the air-bridge were defined on a SiO2, sacrificial layer by electron-beam lithography combined with inductively coupled plasma etching. Thereafter, the span (suspended part between the pillars) patterns were defined with a second electron-beam exposure on a PMMA/PMMA-MAA resist system. The fabrication process was completed by subsequent metal electron-beam evaporation, lift-off in acetone, and removal of the sacrificial layer in a buffered hydrofluoric (HF) solution. Air-bridges with two different geometries (line-shaped and cross-shaped) were studied in detail. The narrowest width of the air-bridges was around 200 nm, and the typical length of the air-bridges was 2-5 mu m. The advantages of our method are the simplicity of carrying out electron-beam exposure with good reproducibility and the capability of more accurate control of the pillar sizes and shapes of the air-bridge. (C) 2007 Elsevier Ltd. All rights reserved.

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本论文旨在开发能使无机材料和有机材料的功能互补、协同优化的无机/有机复合发光材料的制备方法,并研究其发光性质,以发展一类新型的高性能发光材料。首先基于无机组份与有机组份的物理和化学性质的差异,采用能保持其性质均不改变的低温软化学合成法-溶胶-凝胶技术,无机组份选择具有优良光、热稳定性的SiO_2,有机组份选择具有和无机SiO_2相似折射率和优良力学性能的丙烯酸类如甲基丙烯酸甲酯(MMA)和甲基丙烯酸羟乙酯(HEMA),采用两步溶胶-凝胶法和在交联剂3-(三甲氧基硅)丙基甲基丙烯酸酯(MSMA)存在下快速制备了两种杂化基质材料SiO_2/P(MMA-MSMA)和SiO_2/P(HEMA-MSMA)。由于使用两步溶胶-凝胶法,大大缩短了溶胶的成胶时间,所得杂化材料具有良好的光学透明性。实验结果表明,在基质材料中形成了无机网络和聚合物网络,无机相和有机相之间存在着强的化学键,两相间无明显的界面,即形成了互穿网络,粒子的尺寸在100 nm以内,属于纳米材料。由于原位聚合物与无机SiO_2基质同时生成,不仅使杂化基质材料具有一定的韧性,而且可有效降低无机SiO_2凝胶基质的热聚集和光损耗,是制备复合发光材料的优良基质材料。由于TiO_2基质具有较低的声子能量(可降低发光组份的非辐射跃迁几率),也是一种良好的基质材料。研究了在DMF存在下透明TiO_2凝胶基质的快速制备方法。由于DMF上的氮原子可和Ti-OH上羟基形成氢键,从而大大降低了钛酸丁酯的水解速率,避免了钛酸丁酯直接水解时沉淀的出现,通过调节DMF的用量,可以在不同时间内制备透明的TiO_2凝胶。凝胶经热处理后,其结构从无定型态转变为锐钛矿相,经800℃热处理后己全部转变为会红石相。此制备方法不仅快速,而且比现有的溶胶-凝胶法制备金红石相TiO_2的温度至少降低了200℃。基于高分子聚合物聚乙烯醇缩丁醛(PVB)具有良好的成膜性能,采用旋转涂敷法制备了SiO_2/PVB杂化膜,通过调节溶胶的粘度和匀胶的速度,可以制备不同厚度的薄膜,为杂化发光膜的制备提供了依据。基于1,1,4,4-四苯基-1,3-丁二烯(TPB)在蓝光波段其有优良的发光性能,制备了掺杂TPB的SiO_2凝胶,并研究其在溶胶-凝胶过程中光谱性质的变化。由于凝胶基质的“笼保护”效应,掺杂于溶胶-凝胶基质中的TPB具有较高的热稳定性,其热分解温度达460℃。TPB具有较高的猝灭浓度,相对于它的氯仿溶液,TPB在凝胶基质中猝灭浓度提高2~3个数量级。另外,在凝胶基质中比其在氯仿溶液中具有较长的荧光寿命,这对于此类发光材料的实用化具有重要意义。基于基质的组成、微结构及化学环境,可影响发光组份之间的相互作用和能量传递规律,制备了双掺UO_2~(2+)和Eu~(3+)的TiO_2凝胶。由于在TiO_2凝胶基质中Eu~(3+)的激发光谱和UO_2~(2+)的发射光谱具有较大的光谱重叠,研究了它们之间的能量传递机制。实验结果表明,在TiO_2凝胶中,存在着UO_2~(2+)向Eu~(3+)的能量传递过程,其能量转移效率和能量转移速率随Eu~(3+)浓度的增大而增大。通过对Stern-Volmer曲线的分析,得出Eu~(3+)对UO_2~(2+)荧光的猝灭机制主要为稳态猝灭机制,此研究为丌发新的发光材料提供了科学依据。为克服传统溶胶-凝胶法制备光功能材料时预先掺杂法的缺点和局限,缩短制备光功能材料的周期,基于溶胶-凝胶水解、缩聚的特点和稀土配合物的形成规律,首次提出应用两步溶胶-凝胶法于SiO_2基质中快速原位合成了稀土配合物的方法。它是即在用盐酸作为酸性催化剂水解一定时间的溶胶中,加入六次甲基四胺作为碱性催化剂。六次甲基四胺的加入,一方面,加快了凝胶的形成,另一方面,使溶胶的介质逐步适合配合物的形成,最终在凝胶基质的形成中原位合成了稀土配合物。由于采用两步溶胶-凝胶法,缩短了凝胶时间,可在数小时内制备出透明含原位配合物的湿凝胶。采用荧光光谱、吸收光谱、IR光谱及荧光寿命测量等手段,对原位合成稀土配合物的过程进行了跟踪表征。实验结果表明,对于水杨酸-Tb~(3+)配合物的原位合成,在溶胶阶段无配合物的形成,此时,水杨酸向Tb~(3+)的能量传递属于分子间能量传递过程,即扩散控制的碰撞过程;在湿凝胶中,Tb~(3+)与水杨酸形成了配合物,在紫外光激发下,通过水杨酸向Tb~(3+)的分子内能量转移,发出Tb~(3+)强烈的特征荧光。此复合光功能材料制备技术,具有一定的创新性和实用价值。应用上述两步溶胶一凝胶法于SiO_2及SiO_2/聚合物杂化基质中快速原位合成了稀土β-二酮、芳香羧酸及杂环配体phen配台物,并制备了稀土配合物SiO_2/PVB杂化发光薄膜。原位稀土配合物在紫外光激发下发出其相应稀土离子的特征谱线,和纯配合物相比,其激发光谱变为-不对称的宽带,发射光谱表现出较少的劈裂:山于杂化基质的保护作用,原位合成的稀土配合物具有较好的光稳定性和热稳定性;由于原位合成的配合物被固定于基质的微孔中,在IR光谱上,其相关振动吸收较弱;配合物的名义掺杂在0.6 mol%时,发光强度随掺杂浓度的增加而增加,无浓度猝灭现象;SEM表明,含有原位合成的配合物的材料,具有一定的均匀性,粒子尺寸在纳米级范围。为发展多种无机基质稀土有机配合物光功能材料的复合技术,拓宽无机/有机光功能材料的制备方法,首次采用离子交换法将稀土配合物Eu(DBM)_3phen和Tb(AA)_3phen嵌入到层状化合物α-磷酸氢锆(α-ZrP)中,制备了嵌有稀土配合物的组装体,并研究了组装体的光物理性质。基于层状化合物的结构特点,首先将对甲氧基苯胺(PMA)嵌入层状化合物中,得到预组装体,使层间距变大,然后再通过离子交换的方式,制得含有稀土配合物的组装体。XRD光谱和紫外-可见吸收光谱证明配合物组装进了层状化合物中。在紫外光激发下,组装体发出相应稀土离子的特征谱线;和纯配合物粉末相比,其激发光谱发生一定的蓝移,而其发射光谱则表现出较少的劈裂;由于基质的保护作用,组装体中的配合物具有较高的荧光寿命和发光效率。研究、制备了改性MCM-41与稀土配合物Eu(DBM)_3phen的复合组装体发光材料,并研究了组装体的发光性质。由于羟基的高能振动将极大地猝灭稀土离子的荧光发射,所以采用3-氨丙基三乙氧基硅烷、N-[(3-三乙氧基硅)]丙基乙二胺和4-(三乙氧基硅)丁氰三种硅烷化试剂对介孔分子筛MCM-41内壁羟基进行了修饰。组装体在紫外光激发下发出稀土离子的特征谱线,经氨丙基三乙氧基硅烷改性后的组装体,其发光强度约为未改性MCM-41前组装体的9倍,说明了经改性后,减少了基质中的羟基含量,降低了因羟基的高能振动而引起的非辐射跃迁几率,提高了组装体的荧光强度;对不同的改性剂的改性效果的研究表明,经4-(三乙氧基硅)丁氰改性、N-[(3-三乙氧基硅)]丙基乙二胺改性和3-氨丙基三乙氧基硅烷改性MCM-41改性后的的组装体的荧光强度依次增加,同时,稀土离子在其中的荧光寿命也依次增加。以上复合技术为研究和开发具有高效、长寿命的复合发光材料提供了新的可能。为满足不同条件下材料的要求,选择具有优良发光性能的稀土配合物,将其引入P(MAA-St)共聚物的合成过程中,制备了质轻、透明性好的掺杂有稀土配合物的透明发光树脂,并研究了发光树脂的光物理性质。透明发光树脂具有良好的透光性,密度在1.2 g/cm~3;在紫外光照射下,树脂发出稀土离子强烈的特征荧光,在掺杂浓度不大于4wt%时,发光强度随掺杂浓度的增大而增大。稀土配合物在发光树脂中较其在乙醇溶液中具有较长的荧光寿命。与其相应的纯配合物的乙醇溶液相比,稀土配合物在发光树脂中的周围环境极性增大,格位对称性升高。

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含油污泥已作为危险废物列入《国家危险废物名录》(HW08),其处理问题已成为环保领域研究的热点。热洗技术是含油污泥处理的主流技术,而清洗药剂作为该技术的核心,直接影响含油污泥的处理指标与效率。目前,适合热洗处理的化学药剂很少,迫切需要开发专用药剂技术。针对含油污泥清洗效率的难题,本文合成了一种新型高效的含油污泥清洗剂。 本文以甲基丙烯酸(MAA)、丙烯酸丁酯(BA)和苯乙烯(St)为混合单体,偶氮二异丁腈(AIBN)为引发剂,通过溶液聚合的方法探索合成了一种高分子聚合物(命名为MBS)。分析讨论了MBS关键单体的选择、合成设计及方法,检测了MBS有关物理化学性能,考察了单体、引发剂用量及清洗条件对MBS脱油性能的影响,探讨了MBS对含油污泥中原油不同组分的去除效率,并用红外光谱证实了MBS结构的官能团。 MBS在单体质量比为MAA:BA:St=21:62:17,引发剂AIBN为单体总量的1.2%时,含油污泥脱油率可达84%以上。MBS对于含油污泥中芳烃去除率最高,为93.0%;其次是烷烃,去除率为87.4%;沥青质、胶质最低,去除率为71.8%,具有良好的处理效果。 本文还针对目前国内尚无评价含油污泥清洗剂的标准方法,对清洗剂性能评价进行了初探,采用统一标准的模拟含油污泥进行清洗剂性能评价,并提出了制备方法,同时验证了在此基础上所建立的性能评价方法。结果证明,模拟含油污泥能够真实体现清洗剂的脱油性能,所建立的评价方法可以作为一种通用规范的含油污泥清洗剂性能评价的基本方法。

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A sorbent showing specific affinity for nicotine was prepared by molecular imprinting technique, using nicotine as the template, methacrylic acid (MAA) as the functional monomer, ethyleneglycol dimethacrylate (EDMA) as the crosslinker and chloroform as the porogen. UV spectroscopic analysis in the molecular imprinting prepolymerization stage confirmed that nicotine could complex with the functional monomer by electrostatic interaction (ionic interaction and hydrogen bonding). The affinity and the binding properties of the imprinted polymer towards nicotine were investigated by equilibrium rebinding experiments. The results indicated the presence of nicotine-specific binding sites in the imprinted polymer, and that the imprinted polymer had a good capacity (90 mumol/g polymer) for nicotine. The elution conditions were optimized on the column packed with the imprinted polymer to elute nicotine quantitatively. The imprinted polymer was used as a solid-phase extraction (SPE) material for the removal of nicotine from tobacco smoke. The results obtained showed that the imprinted polymer was superior in terms of removing nicotine in tobacco smoke, compared with the commercial filter tip.

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以异丙醇为溶剂,偶氮二异丁腈(AIBN)为引发剂,甲基丙烯酸(MAA)、丙烯酸丁酯(BA)和苯乙烯(St)为混合单体,通过溶液聚合的方法制备一种含油污泥清洗剂。介绍了该清洗剂的制备方法,考察了单体用量及清洗条件对清洗剂脱油性能的影响,探讨了清洗剂对含油污泥中原油不同组分的去除效率,并用红外光谱证实了所制备共聚物结构的官能团。清洗剂性能评价表明:单体用量和清洗条件均有最佳值,其中单体最佳质量比为MAA∶BA∶St=21∶62∶17,最佳清洗条件分别是:加药浓度为250 mg/L,水洗温度为60℃,反应时间为40 m in;清洗剂对含油污泥中芳烃去除率最高,达93.0%。

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采用甲基丙烯酸(MAA)、丙烯酸(AA)为聚合单体,以亚硫酸氢钠-过硫酸铵为引发剂,采用水溶液聚合法制备了聚丙烯酸-甲基丙烯酸P(AA-MAA)。系统地研究了单体浓度、单体配比、反应温度等各项聚合条件对聚合物吸湿性能的影响。

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Graft copolymerization in the molten state is of fundamental importance as a probe of chemical modification and reactive compatibilization. However, few grafting kinetic studies on reactive extrusion have been carried out because of the inherent difficulties, as expected. In this work, we have studied chain propagation kinetics on melt grafting using pre-irradiated linear low density polyethylene (LLDPE) and three monomers, acrylic acid (AA), methacrylic acid (MAA), and methyl methacrylate (MMA), as the model system. We measured the apparent chain propagation rate coefficients of grafting (k(p,g)) and homopolymerization (k(p,h)) at an initial stage for the melt grafting by FT-IR spectroscopy and electron spin resonance spectroscopy. It was observed that the convective mixing affected the rate coefficients. The magnitude of k(p,h) and k(p,g) were in the same order, but k(p,h) was slightly larger than k(p,g) The k(p,g) of the three grafting systems increased in the order: LLDPE/MMA < LLDPE/MAA < LLDPE/AA. These results are explained in terms of phase separation, solubility, and inherent reactivity of the monomer.