利用乙二胺四乙酸淋洗修复重金属污染的土壤及其动力学

通过室内模拟试验,采用振荡淋洗的方法研究了乙二胺四乙酸(EDTA)浓度、pH、淋洗时间对重金属去除效果的影响.利用一级反应动力学模型对试验数据进行拟合,并测定了EDTA处理前后土壤中重金属形态的变化.结果表明,EDTA溶液在浓度为0.1mol.L-1、pH7、淋洗时间1d的条件下能达到对污染土壤重金属的最大去除率,去除率分别为Cd89.14%、Pb34.78%、Cu14.96%、Zn45.14%.模型拟合结果表明,Cd的质量转移系数最大,其次是Zn、Pb和Cu.说明在土壤淋洗过程中,Cd和Zn最先达到质量转移的平衡状态,然后是Pb和Cu.形态分级结果表明,EDTA能有效地去除交换态、碳酸盐结合态和氧化物结合态重金属,而对有机态和残余态部分重金属作用效果不明显.

辽河三角洲滨海湿地景观规划各预案对指示物种生态承载力的影响

在对辽河三角洲滨海湿地进行景观规划“预案”设计以及相应的生境分析基础上 ,运用景观生态决策与评价支持系统 ( LEDESS-model)对指示物种丹顶鹤和黑嘴鸥繁殖生境的生态承载力进行了空间模拟和定量分析 ,结果表明 :在大规模农业开发的背景下 ,预案 A通过湿地调整及生境补偿措施 ,不仅可以维持湿地生境面积“无净损失”( No-net-loss) ,而且可以相当程度地提高指示物种繁殖生境的生态承载力 ;预案 B通过一系列减轻生境破碎化影响的生境管理措施 ,也显著地提高了丹顶鹤繁殖生境的生态承载力 ,但对黑嘴鸥繁殖生境的生态承载力的改善不如前者显著 ;预案 C的模拟结果说明采取“滚动”开发模式 ,可以有效减轻区域农业开发对物种生境的负面影响 ,在本研究限定的开发规模下 ( 80 0 0 hm2 ) ,对指示物种丹顶鹤、黑嘴鸥繁殖生境的生态承载力没有明显影响

Novel Method for Preparation of Polypropylene Blends with High Melt Strength by Reactive Compounding

Ultrafine full-vulcanized polybutadiene rubber(UFBR) with particle sizes of ca. 50-100 nm were used for modifying mechanical and processing performances of polypropylene(PP) with PP-g-maleic anhydride(PP-g-MA) as a compatibilizer for enhancing the interfacial adhesion between the two components. The morphology, dynamical rheology response and mechanical properties of the blends were characterized by means of SEM, rheometer and tensile test, respectively.

Type I collagen-mediated synthesis of noble metallic nanoparticles networks and the applications in Surface-Enhanced Raman Scattering and electrochemistry

In this paper, we demonstrated an effective enviromentally friendly synthesis route to prepare noble metallic (Au, Ag, Pt and Pd) nanoparticles (NPs) networks mediated by type I collagen in the absence of any seeds or surfactants. In the reactions, type I collagen served as stabilizing agent and assembly template for the synthesized metallic NPs. The hydrophobic interaction between collagen and mica interface as well as the hydrogen bonds between inter- and intra-collagen molecules play important roles in the formation of collagen-metallic NPs networks. The noble metallic NPs networks have many advantages in the applications of Surface-Enhanced Raman Scattering (SERS) and electrochemistry detection. Typically, the as-prepared Ag NPs networks reveal great Raman enhancement activity for 4-ATP, and can even be used to detect low concentration of DNA base, adenine.

Enhancement of the electrooxidation of ethanol on Pt-Sn-P/C catalysts prepared by chemical deposition process

In this paper, five Pt3Sn1/C catalysts have been prepared using three different methods. It was found that phosphorus deposited on the surface of carbon with Pt and Sn when sodium hypophosphite was used as reducing agent by optimization of synthetic conditions such as pH in the synthetic solution and temperature. The deposition of phosphorus should be effective on the size reduction and markedly reduces PtSn nanoparticle size, and raise electrochemical active surface (EAS) area of catalyst and improve the catalytic performance. TEM images show PtSnP nanoparticles are highly dispersed on the carbon surface with average diameters of 2 nm. The optimum composition is Pt3Sn1P2/C (note PtSn/C-3) catalyst in my work. With this composition, it shows very high activity for the electrooxidation of ethanol and exhibit enhanced performance compared with other two Pt3Sn1/C catalysts that prepared using ethylene glycol reduction method (note PtSn/C-EG) and borohydride reduction method (note PtSn/-B). The maximum power densities of direct ethanol fuel cell (DEFC) were 61 mW cm(-2) that is 150 and 170% higher than that of the PtSn/C-EG and PtSn/C-B catalyst.

Assembly of the transition metal substituted polyoxometalates ZnW11M(H2O)O-39(n-) (M = Mn, Cu, Fe, Co, Cr, Ni, Zn) on 4-aminobenzoic acid modified glassy carbon electrode and their electrochemical study

Through layer-by-layer assembly, a series of undecatungstozincates monosubstituted by first-row transition metals, ZnW11M(H2O)O-39(n-) (M=Cr, Mn, Fe, Co, Ni, Cu. or Zn) were first successfully immobilized on a 4-aminobenzoic acid modified glassy carbon electrode surface. The electrochemical behaviors of these polyoxometalates were investigated. They exhibit some special properties in the films different from those in homogeneous aqueous solution. The Cu-centered reaction mechanism in the ZnW11Cu multilayer film was described. The electrocatalytic behaviors of these multilayer film electrodes to the reduction of H2O2 and BrO3- were comparatively studied.

Dynamic mechanical studies of the sulfonated butyl rubber ionomers and their blends

Dynamic mechanical properties of sulfonated butyl rubber ionomers neutralized with different amine or metallic ion (zinc or barium) and their blends with polypropylene (PP), high-density polyethylene (HDPE), or styrene-butadiene-styrene (SBS) triblock copolymer were studied using viscoelastometry. The results showed that glass transition temperatures of ion pair-containing matrix and ionic domains (T-g1 and T-g2, respectively) of amine-neutralized ionomers were lower than those of ionomers neutralized with metallic ions, and the temperature range of the rubbery plateau on the storage modulus plot for amine-neutralized ionomers was narrower. The modulus of the rubbery plateau for amine-neutralized ionomers was lower than that of ionomers neutralized with zinc or barium ion. With increasing size of the amine, the temperature range for the rubbery plateau decreased, and the height of the loss peak at higher temperature increased. Dynamic mechanical properties of blends of the zinc ionomer with PP or HDPE showed that, with decreasing ionomer content, the T-m of PP or HDPE increased and T-g1 decreased, whereas T-g2 or the upper loss peak temperature changed only slightly. The T-g1 for the blend with SBS also decreased with decreasing ionomer content. The decrease of T-g1 is attributed to the enhanced compatibilization of the matrix of the ionomer-containing ion pairs with amorphous regions of PP or HDPE or the continuous phase of SBS due to the formation of thermoplastic interpenetrating polymer networks by ionic domains and crystalline or glassy domains.

黄金矿的催化浸取

基于对金自溶解电化学过程的分析，提出此过程受阴极还原反应所控制，加入阴极反应催化剂，能加快金自溶解速度。实验结果充分表明：我们找到的催化剂Ａ能提高金的浸出速度和浸出效率。

SYNTHESIS AND CHARACTERIZATION OF HIGH-PERFORMANCE PA FILM

I. INTRODUCTIONIn last decade, considerable attention was focused on polyacetylene. However, its practical application was affected considerably because of its poor strength and stability. Recently, Narrmann et al. reported that they could synthesize PA film with improved properties using modified Ziegler-Natta catalyst. However, no detailed

Screening of genes expressed in vivo after infection by Vibrio anguillarum M3

Aims: Genes uniquely expressed in vivo may contribute to the overall pathogenicity of an organism and are likely to serve as potential targets for the development of new vaccine. This study aims to screen the genes expressed in vivo after Vibrio anguillarum infection by in vivo-induced antigen technology (IVIAT). Methods and Results: The convalescent-phase sera were obtained from turbot (Scophthalmus maximus) survived after infection by the virulent V. anguillarum M3. The pooled sera were thoroughly adsorbed with M3 cells and Escherichia coli BL21 (DE3) cells. A genomic expression library of M3 was constructed and screened for the identification of immunogenic proteins by colony immunoblot analysis with the adsorbed sera. After three rounds of screening, 19 putative in vivo-induced (ivi) genes were obtained. These ivi genes were catalogued into four functional groups: regulator/signalling, metabolism, biological process and hypothetical proteins. Three ivi genes were insertion-mutated, and the growth and 50% lethal dose (LD50) of these mutants were evaluated. Conclusions: The identification of ivi genes in V. anguillarum M3 sheds light on understanding the bacterial pathogenesis and provides novel targets for the development of new vaccines and diagnostic reagents. Significance and Impact of the Study: To the best of our knowledge, this is the first report describing in vivo-expressed genes of V. anguillarum using IVIAT. The screened ivi genes in this study could be new virulent factors and targets for the development of vaccine, which may have implications for the development of diagnostic regents.

Screening of genes expressed in vivo after infection by Vibrio anguillarum M3

Aims: Genes uniquely expressed in vivo may contribute to the overall pathogenicity of an organism and are likely to serve as potential targets for the development of new vaccine. This study aims to screen the genes expressed in vivo after Vibrio anguillarum infection by in vivo-induced antigen technology (IVIAT). Methods and Results: The convalescent-phase sera were obtained from turbot (Scophthalmus maximus) survived after infection by the virulent V. anguillarum M3. The pooled sera were thoroughly adsorbed with M3 cells and Escherichia coli BL21 (DE3) cells. A genomic expression library of M3 was constructed and screened for the identification of immunogenic proteins by colony immunoblot analysis with the adsorbed sera. After three rounds of screening, 19 putative in vivo-induced (ivi) genes were obtained. These ivi genes were catalogued into four functional groups: regulator/signalling, metabolism, biological process and hypothetical proteins. Three ivi genes were insertion-mutated, and the growth and 50% lethal dose (LD50) of these mutants were evaluated. Conclusions: The identification of ivi genes in V. anguillarum M3 sheds light on understanding the bacterial pathogenesis and provides novel targets for the development of new vaccines and diagnostic reagents. Significance and Impact of the Study: To the best of our knowledge, this is the first report describing in vivo-expressed genes of V. anguillarum using IVIAT. The screened ivi genes in this study could be new virulent factors and targets for the development of vaccine, which may have implications for the development of diagnostic regents.

Transformation of accommodation space of the Cretaceous Qingshankou Formation, the Songliao Basin, NE China

Analysis of accommodation space variation during deposition of the Cretaceous Qingshankou Formation in the Songliao Basin, NE China, indicates that accommodation space changed both through time and across the basin as a seesaw movement. The mid-upper Qingshankou Formation is divided into three units. In each unit, changes of accommodation space differ in the southern and northern part of the basin. Increasing accommodation in the southern part is accompanied by a decrease in the northern part, and vice versa. Between the northern and southern basin, there was a neutral belt that is like a fulcrum, called the transformation belt here, where the accommodation did not change to any significant degree. We call this response 'accommodation transformation', whose characteristics are defined by tectonic subsidence analysis, palaeontological and sedimentary analyses. The accommodation increasing belt, decreasing belt, transformation belt and accommodation transformation boundary together constitute the accommodation transformation system. The recognition of accommodation transformation in the Songliao Basin provides a new insight into sequence stratigraphy and might be widely applicable.

潮间带纤毛虫原生动物和小型底栖动物生态学研究

微型和小型底栖动物是底栖微/小食物网的重要构成。相对浮游生态系统, 迄今国际间对底栖食物网的认知极为欠缺。这一方面是由于微型生物形态和功能上的复杂性和多样性, 另一方面原因在于研究方法的障碍—主要是微型和小型底栖动物的定量提取和定性分析。本研究首先进行了方法学改良, 并应用新方法对底栖微食物网的重要功能类群—纤毛虫原生动物和小型底栖动物进行了不同生境的周年按月采样, 定性及定量研究的同时, 联系环境因子对微型和小型底栖生物的环境监测进行了探讨。 微型和小型底栖生物的定量研究首先涉及到目标生物在沉积物中的有效提取, 目前硅胶液提取是普遍使用的方法, 其中Ludox液主要应用于小型生物, 它不但价格便宜而且比重合适, 因此在常规生态研究中被广为接受。不过, Ludox易与于海水中的阳离子产生凝结而无法直接用于微型生物; 目前唯一直接应用于微型生物提取的是Percoll硅胶液, 但其昂贵的价格使其在常规生态研究中受到极大限制。本研究以价格低廉的Ludox 硅胶液结合定量蛋白银染色 (QPS) 技术开发了一种新的方法, 即Ludox-QPS法。主要流程为: 样品采集与固定、淘洗/稀释降盐、Ludox密度梯度离心、过滤浓缩和琼脂包埋, QPS染色、永久封片及鉴定计数。添加已知数量的纤毛虫至无生物底泥的重获实验表明, 该密度梯度离心的提取率大于94%; 该方法对自然沉积物中纤毛虫的提取率达97.6%, 对沙质、泥沙质和泥质中海洋线虫的提取率分别达97%、96.9% 和97.8%。对比实验表明, 经QPS制片获得的小型动物的丰度和类群数量与传统方法相当或更高, 尤其当小个体虫体占优势时, 该法显示出较传统方法 (导致数量低估) 更为明显的定量优越性。该方法除用于纤毛虫和小型动物的定量分析外, 还具有较高的分类分辨率, 染色后的纤毛虫原生动物大多类群可鉴定到属, 部分可鉴定到种, 以此可在群落水平上研究其生态作用。 根据新开发的Ludox-QPS技术, 在大沽河潮间带依据盐度梯度选定2个站位 (IIQ和营海) 进行了周年按月采样, 对底栖纤毛虫和小型底栖动物进行了定量研究。纤毛虫原生动物在IIQ和营海的年平均丰度分别为2236 inds./10 cm2 和935 inds./10 cm2 (28 inds./ml 和12 inds./ml), 平均生物量分别为119.1 gC/10 cm2和54.2 gC/10 cm2 (1.5 gC /ml 0.7 gC/ml)。丰度的季节变化趋势为: 春天 > 秋天 > 夏天 > 冬天。垂直分布上, 在营海分布于表层0-0.5 cm 的比例为57.1%, 分布于0.5-2 cm、2-4 cm和4-8 cm比例分别为23.1%、11.4% 和8.5%; 13个月中除12月份外, 4-8 cm均有一定数量的纤毛虫分布; 而在IIQ, 97% 的纤毛虫分布在0-0.5 cm, 分布在0.5-2 cm、2-4 cm和4-8 cm比例分别为2.4%、0.4%和0.2%, 4-8 cm的分布只发生在春季和秋季。纤毛虫的多样性季节变化明显, 春秋季物种丰富, 两个站点每毫升沉积物的平均物种数分别为18和6。Two-Way Crossed ANOSIM 分析表明纤毛虫群落在月份间和站点间的差异极其显著。Pseudochilodonopsis sp., Chilodontopsis sp., Euplotes sp.及Prorodon sp.是表征两个生镜中纤毛虫群落的主要类群。 同时, 发现了14个小型生物类群, 其中线虫在IIQ和营海的丰度优势度分别为97.4% 和78.6%。小型动物在IIQ和营海的年平均丰度分别为4793 inds./10 cm2和8915 inds./10 cm2 (60 inds./ml和111 inds./ml), 其生物量分别为1068.8 gC /10 cm2和1790 gC /10 cm2 (13.4 gC/ml和22.4 gC/ml)。小型底栖动物的丰度在IIQ的季节变化为: 夏季 (7888 inds./10cm2) > 秋季 (5447 inds./10cm2) > 春季 (3731 inds./10cm2) > 冬季 (2780 inds./10cm2); 在营海则完全相反: 冬季 (15579 inds./10cm2) > 春季 (10691 inds./10cm2) > 秋季 (6611 inds./10cm2) > 夏季 (4667 inds./10cm2)。小型底栖动物和纤毛虫的相对重要性存在明显的区域和季节差异。 纤毛虫原生动物、小型动物及环境因子的相关分析表明, 纤毛虫的丰度和多样性与温度和盐度及有机质含量显著相关, 与小型动物没有显著相关性; 群落结构分析表明, 温度、有机质和小型动物的丰度的组合与纤毛虫群落丰度的相关系数为0.345; 盐度、脱镁叶绿素、有机质和小型动物生物量的组合与纤毛虫群落多样性的相关系数为0.403。依据海洋线虫和桡足类的比值 (N/C) 推测, IIQ 可能存在严重的有机污染, 营海则存在明显的季节波动, 8月和9月及2月可能是污染最严重的季节, 这种状况在纤毛虫群落结构的CLUSTER聚类中得到验证。虽然目前尚没有形成有关微型底栖生物-纤毛虫原生动物的污染检测的直接依据, 但本研究说明纤毛虫群落的确对环境污染具有一定的感应度, 而且这种感应和利用小型生物的主要类群估算的污染检测 (N/C) 存在一定程度的关联。 90年代早期有关青岛湾有机污染带的研究表明, 经彻底截污后, 其环境状况向良性发展。进一步了解该湾的健康状况, 2006.5-2007.5月对该湾沙质和泥沙质的小型动物进行周年按月采样。小型动物在泥沙质和砂质沉积物中的年平均丰度分别为4853 ± 1292 inds./10 cm2和1528 ± 569 inds./10 cm2; 年平均总生物量分别为1434.1 ± 897.0 gC /10cm2和720.7 ± 353.8 gC/10cm2。沙质底小型生物的丰度季节波动明显, 6月份和12月份最高, 3月份和9月份最低; 泥沙质季节波动不明显, 6月份最高。两个站点均有48%的小型动物分布在0-0.5 cm 表层, 海洋线虫在表层的分布比例分别为48% (泥沙质) 和34% (砂质)。共检获14个小型动物类群, 其中线虫在泥沙质和砂质沉积物中的年平均丰度分别4619 ± 1255 inds./10cm2和1014 ± 376 inds./10cm2, 其丰度优势度分别为95.2%和66.4%。其它在丰度上占优势的类群, 泥沙质依次为多毛类 (1.5%)、甲壳幼体 (1.5%) 和桡足类 (0.7%); 沙质依次为: 甲壳类幼体 (12.6%)、腹毛类 (8.3%) 和 桡足类 (6.2%)。CLUSTER聚类分析表明, 泥沙质和和砂质中小型生物的丰度组成具有64%的相似性。BIOENV分析表明, 温度、盐度、中值粒径和粘土粉砂含量的组合最能解释不同月份之间和不同站位间的差异, 其相关系数为0.614。依据小型生物的丰度和类群组成, 表明泥沙质底尚存一定的有机污染。

南黄海浮游植物的固碳强度与污染物胁迫下海水碳源/汇格局的变化

本论文在解析了南黄海生态环境的基础上，首次研究揭示了浮游植物固碳强度的年际变化及生态反馈机制，获得了东中国近海浮游植物固碳强度及对海域源/汇格局的影响程度；同时，用室内模拟实验探讨了重金属和有机污染物胁迫下海水无机碳体系和源汇格局的变化过程，获得了一些新的认识。主要结论如下： 1. 南黄海浮游植物固碳强度具有明显的时空变化特征，与海域光照、流系和水团变化、海水磷的浓度等因素密切相关，并在一定程度上决定海区碳源/汇的性质。2005年秋季浮游植物日固碳量达9.5万吨，1983-2005年间，南黄海浮游植物固碳强度有降低的趋势，与海水关键营养盐－磷的限制有关。东中国近海浮游植物年总固碳量约为2.2亿吨，约占全球近海浮游植物的年固碳量的2.0%。 在综合分析秋季南黄海水文、化学、生物背景的基础上，系统阐明了海域浮游植物固碳体系的生物地球化学机制。结果表明，2005年秋季南黄海浮游植物固碳强度，即初级生产力变化在 97−701 mgC m-2 d-1之间，平均为307 mg C m-2 d-1；与其关系比较密切的环境因子为海水透明度、盐度、pH、氨氮 (NH4-N)、磷酸盐 (PO4-P) 以及Chl a。在这些因素中，PO4-P对初级生产力的影响最大，显然11月份南黄海的磷是浮游植物生长的限制因子，次之的影响因素是Chl a和NH4-N。 对南黄海源汇格局的研究发现，如果除去涌升流较为活跃的站位（A9、B7、B8、B9、C8、C9、 D9和A1），2005年秋季表层海水pCO2与浮游植物固碳强度明显负相关（r=-0.8，n=23, p<0.001）。在南黄海东部浮游植物固碳强度较高，pCO2值较低；而在西部海区浮游植物固碳强度较低的区域，其pCO2值较高。碳源/汇转折点浮游植物固碳强度为230 mgC m-2 d-1，即小于此值，海区为大气二氧化碳的源，反之为汇，并且CO2汇区浮游植物固碳强度平均值约是CO2源区的2倍多；浮游植物固碳作用，在某一时间和空间尺度内，基本决定了海区的源汇格局。估算结果显示，东中国近海浮游植物固碳量约为222×106t a-1，约为东中国近海通过海－气界面总表观碳汇强度每年1369万吨的16.2倍，仅就浮游植物的年固碳量而言，东中国近海约占全球近海浮游植物的年固碳量的2.0%。 研究揭示了近年来南黄海浮游植物固碳强度具有区域与年际变化明显这一显著特点。一般，近岸区（由黄海沿岸水和表层水控制）内，光照是浮游植物固碳的主要限制因子；从2001年后的大多数年份中，中央区（黄海冷水团控制）的浮游植物固碳强度均与磷酸盐浓度显著正相关，但与氮浓度的相关性不大，说明南黄海生态系统普遍存在着磷限制而非氮限制；混合区终年受黄、东海混合水控制，受到光照条件和营养盐浓度同时影响。根据本次观测所获数据，结合以前研究者的调查资料，我们发现从1983年到2005年，南黄海浮游植物优势种由Bacillariophyta变为Pyrrophyta，浮游植物细胞丰度和Chl a明显下降，浮游植物固碳强度几乎下降了二分之一 （由569.50 mgC m-2 d-1下降至306.83 mgC m-2 d-1），说明南黄海在世界边缘海固碳过程中的作用在降低。经过相关水质参数及生态环境变化的分析，以上现象是对关键营养盐磷的限制以及光限制响应的缘故。此外，研究还发现，由于南黄海初级生产者产量下降所引起的一些生态反馈信息，如浮游动物固碳量的下降和鱼类产量的锐减。 2. 室内模拟实验显示，重金属（铅、铜、镉和锌）及有机污染物（乙醇、丙酮、尿素和多灭磷）对水体生物固碳体系有重要影响，较低浓度时可提高水体的固碳能力，相应水体中的DIC、HCO3-和 Pco2 与对照组相比都明显下降 (P<0.01)；当污染物达到一定浓度后，水体生物的固碳能力明显下降，其有机碳可降解转化为无机碳。当污染物小于转折浓度水体为大气二氧化碳的汇，反之为源。 水体固碳体系对于不同种类、不同浓度的污染物质所表现的受胁迫情况不同，低浓度各污染物（包括重金属和有机污染物）添加组中（对于重金属为0.1和1µmol•L-1，醇和酮分别为<0.5 mol L-1和<0.75 mol L-1），藻干重及固碳量均要大于初始值，说明适量的外源污染可能会促进藻类生长，提高水体的固碳能力，相应水体中的DIC、HCO3- 和PCO2与对照组相比都明显下降 (P<0.01)。当污染物达到一定浓度后，由于其毒害作用，使得水体内生物的固碳能力下降，甚至分解并转化为无机碳，从会引起DIC、HCO3- 和PCO2含量的升高，其含量上升幅度会因固碳体系对不同种类污染物耐受程度的差异而不同。对于尿素和多灭磷，二者浓度分别达到80和20mgL-1时，水体中二氧化碳各参数仍呈现下降趋势，说明在该浓度范围内，大型藻类（如石莼）仍可利用添加物中的氮和磷，将其做为氮源或磷源，促进水体总固碳量的增加。 污染物胁迫对水体碳源汇能力及格局可起到一定的调控作用，与污染物的浓度密切相关，污染物存在着一转折浓度，分别为5µmol L-1（铜）、20µmol L-1（镉） 0.75mol L-1（酮），当污染物添加小于转折浓度并排除其他影响因素时，水体表现为大气CO2的汇，并且适量的增加污染物浓度会使海洋碳汇能力有所增强；而当污染物超出转折浓度时，水体成为CO2的源，其CO2的释放量是随着污染物浓度的增加而增大。对与研究中其他种类的污染物，在实验室设计范围内，水体始终表现为大气CO2的汇。