Ecological consequences of dredged material disposal in the marine environment: a holistic assessment of activities around the England and Wales coastline

This study provides a holistic perspective on the ecological effects of dredged material disposal, both intertidally and subtidally. A number of numerical techniques (univariate, distributional, multivariate and meta-analysis) were used to assess impacts at 18 different disposal sites. The analyses revealed that ecological effects associated with dredged material disposal were dependent on the numerical techniques used, and that impacts were disposal-site specific. Disposal-site communities were generally faunistically impoverished to varying degrees, and impacts following intertidal placement were comparable to those of subtidal placement. We conclude that any assessment of the consequences of dredged material disposal to the coastal environment must take account of site-specific variation in prevailing hydrographic regimes and in ecological status, along with information on the disposal activity itself (mode, timing, quantity, frequency and type of material). As would be expected, variability in the latter presents a significant challenge in attempts to generalise about environmental and ecological impacts.     

“小块并大块”：集约耕地更惠民生——广西龙州县实施上龙土地整理项目纪实

如何让土地产生更大的效益,一直是国土资源管理部门在不断探索攻克的难题,而集约科学地使用土地,是他们开展工作的思路。     

沁水盆地中—南部水文地质控气特征

通过对研究区内水动力场的三维展布和煤层气含量的耦合分析，划分了煤层气不力封闭类型，探讨了水文地质控气的总体特征。     

基质镜质体的煤化作用微环境及其差异演化

在同一样品中，处于硫化铁颗粒外围和硫化铁结核内部的基质镜质体（以下简称基镜体）具不同反射率及地化特征，表明煤层内部煤化作用微环境条件有别导致同类显微组分差异演化，这可能与微应力场和无机元素催化作用不同有关。     

用摄影测量的光束平差法处理经纬仪观测值及其在工业测量中的应用

本文研究了用摄影测量光束平差法处理经纬仪观测值以解决工业应用中控制网精确测量的。为了证明光束法等效于传统的三维网解法，需要将角度观测值转换成虚拟的像片坐标并进行相应的误差传播，文中为此提出了一种投影的数学模型。此外，还研究了在光束平差法中使用未置平经纬仪的观测值。研究中对两个网进行了试验：一个是工业测量中的控制网，另一个是实验室试验控制网。利用第一个网对光束平差法和传统的三维网法进行比较，结果是：     

Effect of iron type on kinetics and carbon isotopic enrichment of chlorinated ethylenes during abiotic reduction on Fe(0)

Four samples of two commercially available iron brands used as substrate for iron permeable reactive barriers (PRBs) were tested for suitability for remediation of perchloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cDCE) and vinyl chloride (VC). Kinetic studies indicate that rates of reaction are enhanced for cDCE and VC on Connelly iron (2.8 x 10(-4) to 6.9 x 10(-4) L/m2/hr and 2.0 x 10(-4) to 9.0 x 10(-4) L/m2/hr, for cDCE and VC, respectively) vs. Peerless iron (3.1 x 10(-5) to 4.6 x 10(-5) L/m2/hr and 2.4 x 10(-5) to 4.1 x 10(-5) L/m2/hr, for cDCE and VC, respectively). Carbon isotopic analyses of the residual chlorinated ethylene (CE) during degradation indicate significant fractionation occurs during reductive dechlorination, with, for example, up to 70% enrichment in carbon isotopic values observed when VC is more than 99% degraded. Comparison of fractionation factors (epsilon) indicates significant differences in carbon isotopic fractionation for different iron types and for different CEs. For the lower CEs (cDCE and VC) in particular, both slower reaction rates and larger fractionation are observed for degradation on Peerless vs. Connelly iron. This is the first study to establish a correlation between the rate of abiotic degradation on Fe(0) and the extent of isotopic fractionation, and the first to confirm consistent differences in these two parameters as a function of iron type. The possibility that these differences in kinetics and carbon isotopic fractionation for cDCE and VC are related to differences in branching ratios between competing hydrogenolysis and beta-elimination reactions during reductive dechlorination on the iron surfaces is discussed.     

煤层显微序列数学模拟及其在煤储层物性评价中初步应用

应用马尔柯夫过程的原理和方法,建立起描述煤层形成过程或显微序列的数学模式,进而通过对研究实例中煤层结构以及煤岩分层孔比表面积的模式拟合,可以模拟出各种显微煤岩类型在煤层中的分布部位以及煤层中煤层甲烷的有利储存部位,对厚煤层物性和储气性能的非均质性特征作出预测,为煤层气开采地质条件评价提供了一条新的思路。     

煤层气生成与煤层气富集：II.有效生气阶段生气量的估算

煤层的生气条件主要通过有效阶段生气量来影响煤层气的富集。有效阶段生气量取决于有效生气阶段的起止煤级及煤中原始有机质的丰度及其组成。本文给出了估算有效阶段生气量的基本公式,重点讨论了煤中原始有机质的丰度和组成的恢复方法,并以沁水盆地南部主要矿区３号和１５号煤层为例,对有效阶段生气量进行了估算。