Tracing environmental lead sources on the Ao mountain of China using lead isotopic composition and biomonitoring

Atmospheric lead(Pb) and other trace metals can transport over long distance and deposit on remote alpine ecosystems. In this work, the soil profiles, litter and dominant mosses along a large altitude were collected on Ao Mountain, Central China, to obtain the spatial distributions of Pb in these materials, decipher the possible factors controlling the distribution, and quantitatively distinguish the natural versus anthropogenic sources of Pb through the Pb isotopic tracing and biomonitoring. The results show that soil Pb concentrations(mg/kg) decreased significantly with depth, and they were markedly higher in the O(42.6± 2.7) and A(36.4 ± 2.2) horizons than in the litter(7.20 ± 1.9) and mosses(28.0 ± 3.9). The Pb enrichment in the surface soils(O and A horizons),litter and mosses existed in the relatively high altitudes, which was attributed to the influences from atmospheric wet deposition, plants, soil physicochemical properties and human activity. ThePb isotopic ratios identified the Pb sources as originating mainly from Chinese coal combustion,mining and smelting. Atmospheric Pb from southeastern, southwestern and northwestern regions could be deposited in the alpine ecosystem by long distance atmospheric transport. The anthropogenic Pb reached over 50% in the O and A horizons, and over 70% in the litter and mosses, which corresponded to the concentrations of 26.9, 17.7, 5.92 and 21.2 mg/kg, respectively. The results indicate that the mutual effects of climate and regional human activity could increase the Pb accumulation in remote alpine ecosystems.     

郑州市冬季采暖期气候变化特征及节能潜力分析

利用郑州市1951—2007年日平均气温资料,按照国家采暖规范从气候角度上确定了符合郑州特点的采暖初终日,较规定的初、终日（11月15日至次年3月15日）有明显推迟和提前的趋势,并分析了采暖期长度及采暖期的气候变化特征,结果表明：进7．90年代特别是21世纪初采暖期明显缩短,平均较80年代缩短了14d左右。在此基础上研究了近57a来采暖期气候条件的变化,并通过构建采暖强度、采暖指数指标,讨论这种变化对能源消耗和环境保护的影响,从科学角度提出节能的可能性。     

复杂地表条件下高斯波束叠前深度偏移(英文)

在复杂地表条件的区域,地震数据的采集和处理是一项极大的挑战。虽然可以通过静校正来消除起伏地表的影响,然而当地表高程以及近地表速度剧烈变化时,简单的垂直时移对地震波场造成的畸变会严重降低偏移成像的质量。基于射线的偏移方法可以直接在起伏地表面进行波场的延拓成像,是解决上述问题的有效手段。本文针对复杂地表条件下的高斯波束叠前深度偏移进行研究,对倾斜叠加公式进行修改,使之包含地表高程以及速度的信息,通过直接在复杂地表面进行平面波的合成,得到了一种具有更高成像精度的改进方法。首先简单介绍常规高斯波束偏移的基本原理和计算流程,并以此为基础,给出复杂地表条件下高斯波束偏移原有的实现方法以及本文的改进方法,最后通过模型和实际资料的试算验证本文方法的有效性。     

混合二维泊松过程的分解算法及其在提取地震丛集模式中的应用.

将一定范围内的地震数据假设为背景地震和丛集地震的叠加，并同时认为背景地震和丛集地震分别满足不同参数的二维泊松过程．通过引入N阶距离概念，将叠加的二维泊松过程转化为一维的混合密度函数，在对距离阶数进行选择的基础上，最终采用遗传算法进行混合密度分解，以达到提取地震丛集模式的效果．文中将该算法应用于我国西南地区松潘及龙陵主震前丛集地震的提取，并与C值的时间扫描结合，深化了这两次大地震前地震活动图象的认识．      

Isolation of PAH-degrading bacteria from mangrove sediments and their biodegradation potential

Surface sediment samples were collected from seven mangrove swamps in Hong Kong SAR with different degrees of contamination. The total concentrations of 16 PAHs in these sediments ranged from 169.41 to 1058.37 ng g⁻¹ with the highest concentration found in Ma Wan and the lowest in Kei Ling Ha Lo Wai mangrove swamp. In each swamp, three bacterial consortia were enriched from sediments using phenanthrene (Phe) as the sole carbon and energy source, and individual bacterial colony showing Phe degradation was isolated and identified by 16S rDNA gene sequence. The consortia enriched from Sai Keng and Ho Chung sediments had highest ability to degrade mixed PAHs in liquid medium, with 90% Phe and Fla (fluoranthene) degraded in 7 days. On the other hand, Kei Ling Ha Lo Wai-enriched consortia degraded less than 40% Phe and Fla. Pyrene (Pyr) was hardly degraded by the consortia enriched from sediments. Bacterial isolates, namely Rhodococcus (HCCS), Sphingomonas (MWFG) and Paracoccus (SPNT) were capable to degrade mixed PAHs (Phe + Fla + Pyr). Their degradation percentages could be lower, comparable or even higher than their respective enriched consortia, depending on the consortium and the type of PAH compounds. These results suggest that PAH-degrading bacteria enriched from mangrove sediments, either as a mixed culture or as a single isolate could be used for PAHs bioremediation.     

光栅栅距检测与线阵CCD细分技术研究

利用线阵CCD分辨率高、像素均匀等特点对光栅莫尔条纹进行细分是目前广泛采用的一种新技术。由于CCD具有自扫描能力，能将光强随空间分布的莫尔条纹信号转换成随时间变化的电信号，从而可以对光栅刻线的像的移动进行精确定位和直接数字化，改变传统莫尔条纹位相细分方法，实现对光栅栅距进行高倍数的细分。     

邻里建成环境对居民外出型休闲活动时空差异的影响——以广州市为例

休闲行为的产生条件一直受到国内外地理学者的重视,邻里建成环境作为结构性制约因素,在休闲行为研究的交叉学科中开始受到重视,但是关注其对休闲行为影响的时间差异的研究严重不足;此外相关研究多从是否产生休闲行为或活动量的角度去验证,缺乏建成环境对休闲空间特征影响的衡量。基于时间地理学理论,以广州市为案例地,结合居民的出行活动日志调查与人口普查数据、土地利用数据、建筑POI普查数据,探讨居民休闲行为时空特征及居住地的邻里建成环境对其产生的影响。研究发现：工作日,居民外出型休闲活动时间呈现出高度集中特征,高度集中于12:00~14:00,活动集聚的时空区域是12:00~14:00、4 km内;休息日,居民外出型休闲活动时间集聚的集中性减弱,活动持续时间增长;活动集聚的时空区域是9:00~20:00、1 km内。邻里建成环境的不同维度指标对休闲活动距离的作用时段与影响程度存在差异。工作日上午并无影响显著的因素;中午,休闲距离主要受到道路交叉口数量和商业中心可达性的负向影响;下午,休闲距离受到道路交叉口数量先负向后正向的影响。休息日上午,休闲距离主要受开敞空间用地比例的负向影响;中午,受开敞空间用地比例、公交站点数和到最近开敞空间距离的负向影响,土地利用混合度则是呈现先正向后负向的影响;下午,受道路交叉口数量和公交站点数的负向影响、休闲设施数量的正向影响。从作用机制来看,休息日是休闲机会和时间成本作用占主导,工作日是休闲环境作用占主导。     

五硼酸铷溶液的物化性质及物种分布

碳酸铷、硼酸化学计量比混合,蒸发溶液,直至五硼酸铷RbB5O8·4H2O晶体析出。经粉末X射线衍射（XRD）、拉曼光谱（Raman spectroscopy）、热重/微商热重/差示扫描量热（TG/DTG/DSC）、原子吸收光谱等实验方法,确定其化学组成及结构。298.15、333.15K时测量溶液的物理化学性质（密度、电导、pH）,并与经验方程进行拟合,研究五硼酸铷溶液的物化性质随浓度、温度的变化规律。根据文献报道的平衡常数,实验测量的pH数据,采用牛顿迭代法进一步研究五硼酸铷溶液中主要存在的硼酸根离子对类型、含量以及物种的形成。     

基于模糊综合评判的选址空间决策支持系统

传统的选址空间决策支持系统的数学模型难以全面考虑复杂、抽象的选址影响因素,难以把一些模糊的约束条件纳入数学模型,因而模型存在一定缺陷。利用模糊综合评判进行选址空间决策支持系统的研究,可以充分利用GIS的空间和非空间信息,且考虑的因素更为全面,极大地避免了人为因素的影响,是对选址决策支持系统数学模型的改进。     

南极国际GPS跟踪站的海潮位移改正

This paper describes the ocean loading tides corrections of GPS stations in Antarctica, such as the Great Wall station and Zhongshan station. Based on the theory of ocean loading tides, the displacement corrections of ocean loading tides on GPS stations in Antarctica are calculated by using the CRS4.0 ocean loading tides model. These corrections are also applied to GPS data processing. The GPS data are analyzed by the GAMIT software with and without these corrections. We compared and analyzed the GPS baseline components to get the differences. The results show that the ocean tidal displacement corrections have obvious effects upon GPS baseline components. Therefore, we should not ignore the ocean loading tides corrections of GPS stations in Antarctica to obtain precise and reliable results.