硫化亚铜电池电极材料的研究

本文对薄膜Cu_2S-CdS太阳电池的十种栅极材料(Au、Ag、Cu、Al、Zn、Ni、Ga、ln、Cd和Ti)进行了评价,采用Ni栅极材料制作的电池,最佳电性能参量为:V_(oc)=470mV,I_(sc)=24.3mA/cm~2,FF=62％,η=6.15％,它有希望作为薄膜Cu_2S-CdS太阳电池栅极,代替价格昂贵的金栅极。采用ESCA技术分析了铝栅极材料性能欠佳的原因,指出材料的表面氧化作用导致了电池串联电阻的增加。

多晶富镉Hg_(1-x)Cd_xTe的电沉积及Hg_(0.09)Cd_(0.91)Te薄膜的光电化学行为

本文研究了在酸性CdSO_4+HTeO_2~+6HgCl_2 电解液中多晶富镉Hg_(1-x),Cd_(?),Te(x>0.5)的电沉积过程,实现了三种离子在同一电位下共沉积的技术。对在钛基底上沉积出的薄膜进行XRD,SEM和EDAX分析,结果表明薄膜为闪锌矿型的多晶结构,分布均匀连续。考察了(1—x)=0.09时多晶薄膜在多硫氧化还原电对液中的光电化学行为,光强为100mW/cm~2时,短路光电流I_(sc)=1.88mA/cm~2,开路光电压V_(oc)=0.25V,填充因子F·F=0.22。由光电化学光谱所确定出的禁带宽度E_g=1.26eV,Mott-schottky曲线给出了电极的平带电位φfb为—1.26V(vs.SCE),从而得到开路光电压V_(oc)可能达到的最大值为0.49V。因此,多晶富镉Hg_(1-x)Cd_xTe薄膜是一种很有潜力的光活性电极材料。

渤海沉积物中氮的赋存形态及其在循环中的作用

为揭示渤海沉积物中氮的生物地球化学循环过程，本文应用自然粒度下的分级分离浸取方法首次对渤海沉积物中氮的形态进行了研究，获得了氮形态分布的地球化学特征；将沉积物氮中可转化和非转化部分定量区别开，并对可转化态中各形态氮对其循环贡献的大小进行了评估；结合底栖生物的分布初步探计了沉积物中氮与生物生产的关系及底栖生物对氮循环的影响。得到的主要结论包括：渤海沉积物中氮的形态分布特征及其控制因素。表层沉积物中IEF-N、CF-N、IMOF-N和OSF-N占TN的比例分别为3.67%，0.31%，0.42%和26.45%，OSF-N是可转化态氮的优势形态。IEF-N 中NH_4~+和NO_3~-具有不同的成岩机制：NH_2~+主要受OC、Es和粘土矿物性质影响，NO_3~-与水体分布密切相关。CF-N含量最小，主要受沉积环境pH值的影响。IMOF-N主要由NH_4~+在Fe~（3+）上的吸附形成，受沉积物的氧化还原环境控制。OSF-N除与物质来源有关外，受到粘土矿物性质及沉积物粒度的影响。Fe、Mn和Co对IEF-N和IMOF-N的成岩作用影响明显，Cu、Pb和Mo对OSF-N的分布产生影响，二者作用的机理不同。表层样中，约69.15%的氮经过早期成岩作用而埋藏，短期内不再参与循环。氮的埋藏通量与沉积物聚积速率呈显著正相关，同时受温度、Eh、OC、盐度、硫化物含量等因素影响。沉积物中C/N和N/P均呈现异常的低值，前者主要是由于沉积物中保留了大量的无机氮，后者主要因为陆地排放大量磷入海以及磷的埋藏效率高于氮所致。柱状样中，IEF-N基本随深度减小，IMOF-N随深度有突变现象，OSF-N随深度的变化表明了矿化作用进行的程度。对沉积物中生源要素分解速率常数有：N>P>C>Si。表层沉积物中可转化态氮占总氮的比例高于深层沉积物。OC/ON随深度减小表明沉积物通过某种机制富集了有机氮。各形态氮在氮循环中作用及渤海氮循环收支。对渤海沉积物中可转化态氮的量进行了估算，IEF-N、CF-N、IMOF-N和OSF-N分别为3.657 * 10~8kg，2.794 * 10~7 kg，3.832 * 10~7kg和2.372平共处* 10~9kg；结合室内模拟的氮的界面交换通量，估算其完全释放所需的时间分别为2.15a，0.16a，0.225a和13.94a。各形态氮释放的顺序与其结合牢固程度一致，即IEF-N>CF-N >IMOF-N>OSF-N，其对界面交换的贡献大小则随时间尺度大小发生变化：随时间尺度增加，IEF-N、CF-N、IMOF-N的贡献逐渐减小，OSF-N的贡献逐渐增大，当时间尺度大到足以使四态氮完全释放时，其贡献的大小与各形态氮的量一致即OSF-N（84.6%）>IEF-N（13.0%）>IMOF-N（1.4%）>CF-N（1.0%）。非转化态氮占总氮的 69.15%，其中由于颗粒物包裹导致的“非转化态”氮为49%，说明粒度的影响非常重要。IEF-N和OSF-N主要存在于颗粒物质外层，是循环的主要参与者，CF-N和IMOF-N绝大部分在内层，对循环的贡献很小。水体中再循环的氮对初级生产力的贡献（74.4%）比沉积物中再循环氮的贡献 （26.1）大得多，二者对生态系统的作用不同，水体再生的营养盐通常在较长的时间尺度上维持初级生产力的平衡，而沉积物中的再生则在很短的时间内通过强烈的混合作用提高初级生产力。沉积物中氮与生物生产的关系及底栖生物对沉积物氮循环的影响。IEF-N和OSF-N的分布均与初级生产力以及浮游植物个体数量的分布具有一定的相似性。沉积物中的IEF-N的作用相当于一个氮营养盐的“储存库”对初级生产力产生影响，其作用机制类似于水体富营养化的正反馈机制。IEF-N能对赤潮的发生起加速作用。底栖生物的分布与氮形态分布具有正的相关性：莱洲湾内IEF-N和OSF-N的分布与该区域高生物量和高密度的大型底栖动物分布一致，说明在底栖生物活动活跃的区域营养盐的再生和流动是高效而迅速的。生物扰动能加速矿化作用的进行，使沉积物在一定深度范围内NH_4~+含量增加，大型底栖动物的灌溉作用使NO_3~-在深层仍有较高的分布。底栖生物的不同种群对营养盐变化的响应不同。

菲律宾蛤仔（Ruditapes philippinarum）对胶州湾生态环境影响的现场研究

本文对我国胶州湾养殖的主要滤食性贝类菲律宾蛤仔的生理生态学进行了系统研究，通过资料收集、现场调查、定点连续观测、现场模拟实验等综合性方法探讨了菲律宾蛤仔养殖对胶州湾生态环境的影响。主要系统调查了不同季节胶州湾自然沉积物中C、N和P的变化；研究了菲律宾蛤仔生物沉积作用的周年变化；同时还研究了不同月份菲律宾蛤仔的耗氧率，排泄率的变化。结果如下: 1、综述了滤食性贝类通过滤食、生物沉积和呼吸排泄等作用对海区环境的影响,系统评述了埋栖性贝类生物沉积的测定方法及其生态效应。国际上已有不少研究专门报道了贝类在海区现场的生物沉积作用，而在我国，关于埋栖性贝类生物沉积特征的研究较少。 2、在胶州湾红岛附近养殖海区，从2003年10月到2004年7月以及2005年8月到2005年12月对菲律宾蛤仔生物沉积进行了现场测定。大、中和小规格菲律宾蛤仔生物沉积速率范围分别为121.6～1527.4mg/ind·d，49.5～902.1mg/ind·d，14.2～653.9mg/ind·d。海底自然沉积物OM分别为3.1％和5.7±1.1％。而大、中和小规格菲律宾蛤仔生物沉积物的OM分别为6.2±1.2％、5.9±1.3％和6.1±1.4％。大、中和小菲律宾蛤仔生物沉积物TP含量分别为399±26ppm，372±16ppm，345±15ppm。大、中和小规格蛤子生物沉积物中的OP分别为80±17ppm，92±12ppm和102±10ppm，明显高于对照沉积物的OP。生物沉积物中的OP/TP要明显高于对照沉积物，前者为23～25％，而后者仅为20％。菲律宾蛤仔生物沉积速率呈明显季节性变化，其与软体干重呈异速方程关系，a值的变化范围为0.85～4.50（平均为2.32）。菲律宾蛤仔贝肉的OC和ON含量分别为40.80±7.59％和的10.26±2.19％。贝壳的OM、TP、OP、OC和ON含量分别为3.28±0.47%、109.2±16.6ppm、64±22.9ppm、12.21±0.30％和0.19±0.05％。 3、不同规格菲律宾蛤仔的代谢率呈明显季节变化。7月份，单位个体菲律宾蛤仔耗氧率最高为1.72 g/ind•h；8月份，排氨率和排磷率达到最高，分别为2.44μmol/ind•h、0.58μmol/ind•h。菲律宾蛤仔的O:N在10.7~31.9范围内，O:N和N:P具有明显的季节变化，8月份最大。 4、研究了本湾底质环境特征，测定了自然沉积物的OM、OC、ON、TP和OP的含量。胶州湾站位沉积物的有机质和C、N、P含量季节变化不大，有机质含量大约为3.5％，OC和ON含量大约为0.7％和0.06％。TP含量为285ppm左右，OP含量大约为50ppm。养殖海区沉积物有机质和C、N、P的含量明显高于非养殖海区沉积物含量，其C/N、C/OP和OP/TP一般也比非养殖海区站位高。 夏季，胶州湾菲律宾蛤仔养殖区（平均密度按600ind/m2计算）单位面积（m2）的生物沉积速率平均为176g/m2•d，对于整个海湾，将有1.2万吨的悬浮颗粒物通过贝类排粪作用沉积到海底。通过菲律宾蛤仔的呼吸作用，单位面积（m2）的耗氧量为6.67gO2/m2•d；同时从海底向水体释放大约为16.7μmolN /m2•d和3.3μmolP/m2•d的溶解态N和P；对于整个海湾，菲律宾蛤仔将耗掉水体中的467T/d氧气，同时向水体中释放16.4T/d氨氮和7.2T/d无机磷。对于半封闭的胶州湾，大规模菲律宾蛤仔的滩涂养殖其产生的生物沉积物聚集于海底可能会对海区底部的物理化学和生物环境产生很大影响；而氧的消耗、氨和无机磷的排泄，会对水层中的物理化学环境和营养盐循环产生很大影响。从而由此推测，菲律宾蛤仔高密度大规模的养殖，在整个胶州湾水层－底栖系统耦合作用中可能起着很重要的作用。

海洋沉积物中磷化氢的分布、释放与转化研究

磷化氢（PH3）是磷循环的气相载体，以气体自由态和基质结合态（MBP）两种形式存在于环境中。自然环境中磷化氢的发现是对磷生物地球化学循环的重要补充，它在磷循环中的地位和作用及产生机制开始成为人们关注的热点。目前国内外在湖泊、陆地土壤及大气中已开展了较为广泛的研究，但是关于海洋中的研究还较少。开展磷化氢在海洋沉积物中的分布特征，及其释放通量、与其它磷形态的转化、对微藻生长的影响等行为研究对弄清海洋环境中磷化氢的迁移转化机制及其在磷循环中的作用和地位具有重要的科学意义。 本论文以不同环境条件下的海洋沉积物为研究对象，采用野外实验与室内模拟相结合的方法，运用改进的柱前二次低温冷阱富集和气相色谱-氮磷检测器联用技术等分析手段，系统研究了海洋沉积物中磷化氢的分布特征、环境因子对其分布的影响、沉积物磷化氢向水体、大气中的释放、迁移、转化规律；初步了解了海洋沉积物中结合态磷化氢的分布特征及其释放通量；揭示了磷化氢对海洋环境的可能影响。主要研究结果如下： MBP广泛存在于海洋沉积物中。中国沿海表层沉积物中MBP的浓度范围为：0.89-25.86 ng/kg, dry，其分布也表现出一定的空间分布特征，在同一离岸断面上，有近岸浓度高，远岸浓度低的分布规律；在北黄海、南黄海、东海北部海域、东海南部海域和南海海域的平均浓度分别为：5.57±3.78、3.78±2.81、5.27±3.07、5.48±4.05 和 13.52±7.86 ng/kg dry，与其它海域相比，南海海域的MBP浓度要相对较高一些。长江口海域表层沉积物中MBP的浓度范围为：1.93-94.86 ng/kg, dry。其分布也表现出一定的空间和季节分布特征。上游河口沉积物中MBP的浓度要普遍高于下游河口，平均浓度分别为31.34和4.79 ng/kg, dry。靠近石洞口、竹园排污口以及黄浦江口的S3和S4站位处MBP的浓度要显著高于其它站位，季节平均浓度分别为43.01和61.54 ng/kg, dry。MBP浓度的季节差异并不显著，上游河口和下游河口MBP浓度表现出相似的季节变化特征，一般来说8月和11月要稍高于2月和5月。澳大利亚伊拉瓦拉海湾柱状沉积物中的MBP表现出一定的垂直分布特征。两个柱状沉积物样品均在中下层存在MBP的高值区，且该海湾MBP的含量要远高于中国近海及长江口海域MBP的含量，两个柱状沉积物中MBP的平均浓度分别为637.3和542.6 ng/kg, dry。 环境因子与MBP含量关系的研究结果表明：较高的TP、OP、IP、OC、TN含量均有利于高浓度MBP的产生；TP、OP、OC与MBP含量之间存在着较强的线性相关关系，是控制MBP分布的主要因素；氧化还原电位与MBP含量存在着显著的线性负相关，说明还原环境更有利于沉积物中高浓度MBP的存在；平均粒径与MBP含量存在着一定的线性负相关，说明小粒径有利于高浓度MBP的存在；水深、上升流引起的扰动等也是影响MBP分布的可能原因。并且，在本论文对中国沿海沉积物、长江口沉积物和澳大利亚海湾沉积物的研究中，均得到了MBP含量与OP存在着强烈的线性相关关系，而与IP的线性相关关系较弱或不相关的结论，说明海洋沉积物中的MBP更可能来源于微生物对有机磷成分的降解。另外，长江口海域沉积物中MBP含量与上层海水中活性磷酸盐、总磷、叶绿素a的含量也存在着一定的线性相关关系，说明沉积物中磷化氢的释放可能会对上层水环境产生影响。 静态箱法释放通量的研究结果显示，胶州湾海域沉积物存在着磷化氢的释放现象。沉积物-大气界面和水-大气界面磷化氢的释放通量分别为：27.77和17.37 ng/(m2•h)，该结果要高于Louisiana湿地、水稻田和太湖水体磷化氢的排放通量。并据此估算出胶州湾的磷化氢年排放量为75.75kg/y，高于太湖及比利时垃圾填埋场的磷化氢年排放量。不同底质沉积物释放磷化氢的顺序为：虾池沉积物>滩涂沉积物>海滩黑泥沉积物>海滩排污口旁的砂质泥；践踏能显著促进磷化氢的释放。磷化氢的释放通量与沉积物中MBP的含量有显著的线性相关关系；胶州湾养殖池、滩涂沉积物及海域水体是大气中磷化氢的重要来源，沉积物中的磷化氢可连续向上层水体或大气中释放。晴天，胶州湾近海海域空气中磷化氢的浓度范围为1.06-16.90 ng/m3，且表现出早上和傍晚高，中午时分相对较低的变化规律；空气中磷化氢的浓度与光照强度及释放源释放量的大小有关。 利用室内模拟方法，研究了磷化氢在海水中的转化过程及其对海洋微藻生长的影响，并得出了一些初步结论。日光灯照射条件下，通入海水中的磷化氢可部分转化为磷酸盐和总磷，并且转化后主要以磷酸盐的形式存在。环境条件会对该转化过程产生影响，避光条件下，磷化氢的转化率较低，日光灯照射和紫外灯照射均能促进该转化过程，特别是紫外灯照射，促进效果显著；添加氧气或三价铁离子氧化剂也能促进该转化过程。微藻生长实验结果表明，适量磷化氢气体的通入，能显著刺激并促进磷限制条件下东海原甲藻和赤潮异弯藻的生长，但这种刺激作用并不是无限制的，后期刺激生长作用会变弱或停止生长；低量磷化氢气体的通入，刺激作用不明显；高量磷化氢气体的通入，则会抑制两种海洋微藻的生长。东海原甲藻和赤潮异弯藻对通入磷化氢的响应略有差异，后者对磷化氢的反应更为灵敏； 次磷酸盐和亚磷酸盐也都能刺激两种海洋微藻的生长，但与磷化氢相比，其影响作用相对较小。 本论文的初步研究结果表明，在磷的海洋生物地球化学循环中，需要考虑磷化氢的作用，其长期、连续的释放对磷循环的贡献不可忽视，并可能是磷限制海域赤潮形成的补充机制。

Studies on the regional feature of organic carbon in sediments off the Huanghe River Estuary waters

Organic carbon (OC) in definitely small area sediments(according to marine dimension)off the Huanghe River Estuary is investigated in order to evaluate the feature of regional difference of physical and chemical properties in marginal sea sediments. The distributions of OC in sediments with natural grain size and the relationship with the pH, Eh,Es and Fe3+/Fe2+ are discussed. In addition,OC decomposition rates in surfacial/subsurfacial sediments are estimated. OC concentrations range from 0.26% to 1.8%(wt)in the study area. Significant differences in OC content and in horizontal distribution as well as various trends in surfacial/subsurfacial sediments exhibit the feature of regional difference remarkably in marginal sea sediments. The complicated distribution of OC in surface sediments is due to the influence of bacterial activity and abundance, bioturbation of benthos and physical disturbance. The OC decomposition rate constant in surfacial/subsurfacial sediments ranges from 0.0097 to 0.076 a(-1) and the relatively high values may be mainly related to bacteria that are mainly responsible for OC mineralization;meio-and macrofauna affect OC degradation both directly, through feeding on it, and indirectly through bioturbation and at the same time coarse sediments are also disadvantageous to OC preservation. In almost all the middle and bottom sediments the contents of OC decrease with the increase of deposition depth, which indicates that mineralization of OC in the middle and bottom sediments has occurred via processes like SO42- reduction and Fe-oxide reduction.

Distribution characteristics of matrix-bound phosphine along the coast of China and possible environmental controls

Matrix-bound phosphine (MBP) concentrations in surface sediments collected from 37 stations along the coast of China in 2006 are reported. MBP was found in all samples and the average concentration was 6.30 ng kg(-1) dry weight (dw). The distribution of MBP showed certain spatial variation characteristics with high MBP concentrations at stations near to the coast. The average concentrations of MBP in the northern Yellow Sea (NYS), the southern Yellow Sea (SYS), the northern area of East China Sea (NECS), the southern area of East China Sea (SECS), and South China Sea (SCS) were 5.57 +/- 3.78, 3.78 +/- 2.81, 5.27 +/- 3.07, 5.48 +/- 4.05 and 13.52 +/- 7.86 ng kg(-1) dw. respectively. The correlations between MBP and influencing factors, such as the sedimentary environmental characteristics (sediment type, the grain size, contents of phosphorous, organic matters and redox potential) and the aquatic environmental characteristics (temperature, salinity, depth and hydrodynamics) were studied. The results indicated that MBP was strongly influenced by various factors, such as total phosphorus (TP), organic phosphorus (OP), organic carbon (OC), the grain size and hydrodynamics, all of which not only offered reasonable interpretations for the distribution characteristics of MBP but also provided evidence to support the viewpoint that phosphine originated from OP decomposition. This work is the first comprehensive study of the distribution of MBP along the coast of China and its relationships with environmental factors which will lead to a better understanding of the phosphorus (P) biogeochemical cycle in the sea. (C) 2008 Elsevier Ltd. All rights reserved.

Seasonal and spatial distribution of matrix-bound phosphine and its relationship with the environment in the Changjiang River Estuary, China

Sediment is commonly considered as a source of phosphine, which is a highly toxic and reactive atmospheric trace gas. This study aims to investigate the seasonal and spatial distribution of matrix-bound phosphine (MBP) and its relationship with the environment in the Changjiang River Estuary. A total of 43 surface sediments were collected in four seasons of 2006, and concentrations of MBP and relative environmental factors were analyzed. MBP ranged from 1.93 to 94.86 ng kg(-1) dry weight (dw) with an average concentration of 17.14 ng kg(-1) dw. The concentrations of MBP in the tipper estuary were, higher than those in the lower estuary, which could be attributed to greater pollutant inputs in the upper estuary. The concentrations of MBP also varied with season, with November > August > May > February. Significant correlations existed between MBP and total phosphorus (TP), organic phosphorus (OP), inorganic phosphorus (W), organic carbon (OC), total nitrogen (TN), the grain size, and redox potential (Eh), suggesting that these sedimentary environmental characteristics played an important role in controlling the MBP levels in the sediments. Notably, there were positive linear relationships between the concentrations of soluble reactive phosphorus (SRP), TP, and chlorophyll a (Chl a) in bottom water and MBP in sediments. These relationships might be very complicated and need further exploration. This work is the first comprehensive study of the seasonal and spatial distribution of MBP in sediments and its relationships with environmental factors in a typical estuary, and will lead to deeper understanding of the phosphorus (P) biogeochemical cycle. (C) 2008 Elsevier Ltd. All rights reserved.

Organic carbon source and burial during the past one hundred years in Jiaozhou Bay, North China

Organic carbon (OC), total nitrogen (TN), and Pb-210 in core sediment were measured to quantify the burial of organic carbon and the relative importance of allochthonous and autochthonous contributions during the past one hundred years in Jiaozhou Bay, North China. The core sediment was dated using Pb-210 chronology, which is the most promising method for estimation of sedimentation rate on a time scale of 100-150 years. The variation of the burial flux of organic carbon in the past one hundred years can be divided into the following three stages: (1) relatively steady before 1980s; (2) increasing rapidly from the 1980s to a peak in the 1990s, and (3) decreasing from the 1990s to the present. The change is consistent with the amount of solid waste and sewage emptied into the bay. The OC:TN ratio was used to evaluate the source of organic carbon in the Jiaozhou Bay sediment. In the inner bay and bay mouth, the organic carbon was the main contributor from terrestrial sources, whereas only about half of organic carbon was contributed from terrestrial source in the outer bay. In the inner bay, the terrestrial source of organic carbon showed a steady change with an increase in the range of 69%-77% before 1990 to 93% in 2000, and then decreased from 2000 because of the decrease in the terrestrial input. In the bay mouth, the percentage of organic carbon from land reached the highest value with 94% in 1994. In the outer bay, the sediment source maintained steady for the past one hundred years.

Capacity of soil to protect organic carbon and biochemical characteristics of density fractions in Ziwulin Haplic Greyxems soil

Physical protection is one of the important ways to stabilize organic carbon in soils. In order to understand the role of soils as a carbon sink or source in global climatic change and carbon cycles and properly manage soils as a carbon sink, we ought to know how many organic carbon (OC) in a given soil could be protected. By a density fractionation approach and ultrasonic technique, each soil sample was divided into three fractions: free light fraction (free-LF), occluded fraction (occluded-LF) and heavy fraction (HF). The obtained fractions were analyzed for total OC content, carbohydrate content and recalcitrant OC content. The results showed: (i) In the whole soil profile, dominance of OC consistently decreased in the following order: HF, free-LF, occluded-LF. This suggested that OC in soils were mostly protected. From 0-10 to 60-80 cm horizons, the OC in free-LF decreased from 25.27% to 3.72%, while OC in HF they were increased from 72.57% to 95.39%. The OC in occluded-LF was between 2.16% and 0.89%. (ii) Organic carbon recalcitrance in free-LF was similar to that in HF, and was even higher than that in HF below the surface horizon. This suggested that free-LF was not always the most fresh and non-decomposed fraction. OM quality of HF was higher than that of free-LF in the surface 10 cm below, namely the protected OM had higher quality than free OM in these horizons.

企业经营系统的对象模型──资金流模型

本文阐述了大型工业企业综合自动化系统体系结构中经营管理层的对象模型（资金流模型）。首先论述了该模型在自动化体系结构中的地位和作用，然后分析了企业生产经营过程中发生的资金流，提出用借贷流程图方法表达资金流模型，并将这一方法与国际通用的借贷记帐法相联系，从而揭示了资金流模型与会计核算的内在联系．本文还对企业生产与经营活动的几个主要过程用借贷流程图进行了细化描述。

中国西部大气和雪冰黑碳及其传输过程研究

Glaciers in west China are the sources of the major great rivers in Asia, and the solid water resources are crucial to China and South Asia. Black carbon (BC) results in very complex climate effects not only in the atmosphere, but accelerates the melting after its deposit on the surface of snow/ice. As the main distributed area of glaciers in China, the Tibetan Plateau (TP) and Xinjiang region are abutted by South Asia, Central Asia, and Russia, and east China, and the atmospheric environment would be influenced by the BC emitted from these regions. Whereas, the BC’s temporal and spatial distributions for concentration in the mid and top troposphere in west China, its transport, and its radiative forcing after deposited on the snow/ice surface are not well understood at the present. In the field, we collected samples from surface snow, snow pits, ice core, and aerosol in the glaciers, analyzed BC content mainly by the thermo-oxidized method in the laboratory, and discussed temporal and spatial distributions for BC concentrations in glaciers, the transport, and its impacts on the environment. Several conclusions were derived as follows: 1_Spatial distribution and the impact on albedos for BC concentrations in snow/ice: the BC concentrations in the surface snow for the investigated glaciers could be placed in areas, the Tianshan Mountains ＞ the central TP ＞ the Pamirs ＞ the Qilian Mountians ＞ the Himalayas. This distribution could be attributed to the elevation of the glaciers, the topography of the TP, and more regional emissions. Probably significant impacts on the albedos of the glacier surface could be caused by BC deposits, and the estimated reduced albedos on the glaciers are 9.8% (the Zhadang glacier), 8.7% (the Miao’ergou Riverhead No.3 glacier), and 6.8% (the Kuitun River Haxilegen No.48 glacier), and 6.2% (the Dongkemadi glacier), and 5.3% (the La’nong glacier), and 4.2% (the Muztagata glacier), etc. 2_The temporal variance of BC concentrations in ice of the East Rongbuk Glacier (ERG) and its climatic implications: major cations and anions (e.g., SO42- and Ca2+) concentrations in aerosols during summer monsoon seasons showed their close relationships with the sources of air masses, in which the variance of SO42- concentrations suggested the atmospheric environment over the ERG was significantly influenced by the aerosols from South Asia. BC record based on an ice core suggested its deposit was dominantly transported by monsoons in summers and by westerlies in other seasons, and the BC from South Asia in summers dominated the varying trend of its concentrations in the ice core and caused higher concentrations in summers than those in other seasons. In the past 50 yrs, BC concentrations showed fluctuations, whereas showed an increasing tread in the most recent decade, and exceeded 50 μg kg-1 in the summer of 2001; correspondingly, the radiative forcing caused by BC showed an increasing trend since 1990s, and exceeded 4.5 W m-2 in the summer of 2001. 3_Cabonaceous aerosols in the Nam Co region: organic carbon (OC) concentration accounted for ～95% and BC for ～5% in the total carbonaceous aerosol concentration, which was significantly influenced by summer precipitations. OC was dominantly derived from fossil fuel burning and BC from both fossil fuel and biomass burning. Trajectory analysis and aerosol optical depth suggested the atmospheric environment in the Nam Co region was most probably influenced by the emissions from South Asia. The potential source regions of air pollutants in the Nam Co regions in summers might be Bangladesh and east India, and in winters might be the Indo-gangetic basin. The scavenging ratio of atmospheric BC by rainfalls was less than those at other sites. West China is a less-developed region for industry, where BC concentrations in the atmosphere and snow/ice could be significantly influenced by the emissions from the abutted regions with rising industries (South Asia, Central Asia, and Russia). For example, snow/ice BC concentrations in the glaciers of the Parmirs, the Tianshan Mountains, and the Qilian Mountains in the northeast margin of the TP might be more influenced by the emissions from Centrial Asia (transported by the westerlies), those in the glaciers of the Himalayas might be more influenced by the emissions from South Asia (transported by the monsoons and the westerlies), and atmospheric carbonaceous aerosols might also be more influenced by the emissions from South Asia (transported by the monsoons and the westerlies). The BC concentrations in some glaciers might cause significant impacts on the albedos for the glaciers, and therefore enhanced the radiative forcings, for example, the ERG. The research on the relationships among atmospheric and snow/ice BC and its radiative forcing, variance of snow cover, mass balance of glaciers, and climate forcing would be needed in future.

Estimation of soil organic partition coefficients: from retention factors measured by soil column chromatography with water as eluent

The retention factors (k) of 104 hydrophobic organic chemicals (HOCs) were measured in soil column chromatography (SCC) over columns filled with three naturally occurring reference soils and eluted with Milli-Q water. A novel method for the estimation of soil organic partition coefficient (K-oc) was developed based on correlations with k in soil/water systems. Strong log K-oc versus log k correlations (r>0.96) were found. The estimated K-oc values were in accordance with the literature values with a maximum deviation of less than 0.4 log units. All estimated K-oc values from three soils were consistent with each other. The SCC approach is promising for fast screening of a large number of chemicals in their environmental applications. (C) 2002 Elsevier Science B.V. All rights reserved.

Linear solvation energy relationships regarding sorption and retention properties of hydrophobic organic compounds in soil leaching column chromatography

The capacity factors of a series of hydrophobic organic compounds (HOCs) were measured in soil leaching column chromatography (SLCC) on a soil column, and in reversed-phase liquid chromatography on a C-18 column with different volumetric fractions (phi) of methanol in methanol-water mixtures. A general equation of linear solvation energy relationships, log(XYZ) = XYZ(0) + mV(1)/100 + spi* + bbeta(m) + aalpha(m), was applied to analyze capacity factors (k'), soil organic partition coefficients (K-oc) and octanol-water partition coefficients (P). The analyses exhibited high accuracy. The chief solute factors that control log K-oc, log P, and log k' (on soil and on C-18) are the solute size (V-1/100) and hydrogen-bond basicity (beta(m)). Less important solute factors are the dipolarity/polarizability (pi*) and hydrogen-bond acidity (alpha(m)). Log k' on soil and log K-oc have similar signs in four fitting coefficients (m, s, b and a) and similar ratios (m:s:b:a), while log k' on C-18 and log P have similar signs in coefficients (m, s, b and a) and similar ratios (m:s:b:a). Consequently, log k' values on C-18 have good correlations with log P (r > 0.97), while log k' values on soil have good correlations with log K-oc (r > 0.98). Two K-oc estimation methods were developed, one through solute solvatochromic parameters, and the other through correlations with k' on soil. For HOCs, a linear relationship between logarithmic capacity factor and methanol composition in methanol-water mixtures could also be derived in SLCC. (C) 2002 Elsevier Science Ltd. All rights reserved.

A column method for determination of soil organic partition coefficients of eight pesticides

A column method was developed to conveniently and reliably determine the soil organic partition coefficients (K-oc) of three insecticides (methiocarb, azinphos-methyl, fenthion), four fungicides (triadimenol, fuberidazole, tebuconazole, pencycuron), and one herbicide (atrazine), in which real soil acted as a stationary phase and the water solution of pesticide as an eluent. The processes of sorption equilibrium were directly shown through a breakthrough curve(BTC). The log K-oc values are 1.69, 1.95, 2.25, 2.55, 2.69, 2.67, 3.10, and 3.33 for atrazine, triadimenol, methiocarb, fuberidazole, azinphos-methyl, tebuconazole, fenthion and pencycuron, respectively.