The effectiveness of double hulls in reducing vessel-accident oil spillage

While much work has been done in investigating determinants of oil spillage attributed to vessel accidents, little research has been conducted on the effectiveness of ship hull design in reducing marine pollution. This paper addresses whether the double-hull requirement reduces vessel-accident oil spillage. The volume of oil spillage due to oil-cargo vessel accidents was investigated using tobit regressions and an empirical data set of individual vessel accident pollution incidents investigated by the US Coast Guard from 2001 to 2008. The results indicate that the double hull design on average reduces the size of oil spills by 20% and 62% in tank barge and tanker ship accidents, respectively.     

关于煤层气试井过程中重点问题的研究

煤层气试井是一种以渗流力学理论为基础,以各种测试仪表为手段,通过对煤层生产动态的测试来研究煤层、气、水层和测试井的各种物理参数、生产能力以及煤层、气、水层之间的连通关系的方法。     

自适应卡尔曼滤波在地表沉降监测中的应用

方差补偿自适应卡尔曼滤波是在对观测数据进行递推滤波的同时,不断的对难以确定的模型参数和噪声进行估计和修正,以减小模型误差,使滤波结果更准确。本文采用方差补偿自适应卡尔曼滤波预测模型,对某矿区首采工作面地表沉降监测数据进行计算,得到相应的预测值,并与标准卡尔曼滤波预测值进行比较。探讨了方差补偿自适应卡尔曼滤波预测模型进行矿区地表沉降预测的可行性。     

内蒙古呼山盆地北东段含煤地层及煤层特征

内蒙古呼山盆地北东段勘查区位于海拉尔中新生代凹陷,含煤地层主要为白垩纪伊敏组.根据勘查区已有的地质资料及最新的详查成果,认为勘查区总体构造形态为一复式向斜,地层产状平缓,构造中等;根据岩性特征伊敏组分为下、中、上三段,可采煤层主要集中在上段和下段,煤层厚度变化大,在同沉积向斜轴部煤层厚度大、向两翼及盆地边缘逐渐变薄直至尖灭,其中煤3～4厚度大,为大部可采的较稳定煤层.该区煤炭资源丰富,经估算煤炭资源总量为228 390万t,适宜规划设计大型、特大型机械化开采矿井,具备建设大型煤电和煤化工能源基地的条件.     

宁阳-汶上煤田鲁西井田岩浆岩特征及其对煤层煤质的影响

宁阳-汶上煤田鲁西井田内的岩浆顺煤层或煤层顶底板侵入,对煤层和煤质都有严重影响。该文分析研究了岩浆岩的侵入层位、层数、厚度、岩性及其矿物成分,初步探讨了岩浆岩的来源、地质时代及其对煤层、煤质的影响。     

青海省东昆仑昆中断裂带哈图段地质特征及成矿预测

昆中断裂带是东昆仑成矿带发育多条巨型断裂构造之一,控制并切割自元古宙以来的不同地质体,对区域成矿具有明显的控制作用,其次级断裂或主断裂构造的交叉部位往往是成矿通道和容矿部位。研究区位于昆中断裂两侧,属活动区造山带,成矿期次多,类型复杂,具有良好成矿地质条件,已发现矿床、矿（化）点多处,与Nb,Y,La,Cu,Zn,Mo,Au,Ag,As,Pb元素为主的地球化学异常对应较好。     

宁阳—汶上煤田鲁西井田岩浆岩特征及其对煤层煤质的影响

宁阳—汶上煤田鲁西井田内的岩浆顺煤层或煤层顶底板侵入,对煤层和煤质都有严重影响。该文分折研究了岩浆岩的侵入层位、层数、厚度、岩性及其矿物成分,初步探讨了岩浆岩的来源、地质时代及其对煤层、煤质的影响。     

三株嗜盐古菌诱导形成白云石

白云石成因问题是地质学上长期悬而未决的难题之一.近年来,微生物诱导白云石沉淀逐渐成为白云石成因的重要理论之一,但其中微生物的作用机理远未探明.现生白云石主要分布于高盐环境,该环境中的优势菌群为嗜盐菌,包括嗜盐细菌和嗜盐古菌.因而此次选取三株嗜盐古菌Natrinema sp.J7-1、Natrinema sp.J7-3和Natrinema sp.LJ7,研究其诱导白云石沉淀的能力,并对比不同细胞浓度对白云石沉淀的影响,以期更深入地了解微生物在白云石形成中的作用.通过X射线衍射 (XRD) 检测沉淀物的物相,利用扫描电子显微镜 (SEM) 观察所得矿物形态,同时辅以能量色散谱分析 (EDS) 分析矿物的元素组成.实验结果表明三株嗜盐古菌皆可诱导球型、哑铃型、花椰菜型以及球形聚集体等白云石的形成,且在较高细胞浓度下诱导形成的矿物中白云石含量增多.分析表明细胞浓度的增加会导致细胞表面羧基含量的增加,从而为白云石的沉淀提供更多的成核位点,有利于Mg进入矿物晶格,从而诱导白云石沉淀,本结果进一步提高了对微生物白云石成因机理的认识.      

郯庐断裂带中南段重磁特征与深部构造

郯庐断裂带是中国东部地球物理场的分界线。它在磁场上呈现出一条NNE向线性正磁异常带,它的重力场特征表现为规模较大的布格重力异常梯度带。在断裂带的两侧,其区域磁场、区域重力场无论是场值大小,还是异常规模以及各异常的展布形态等诸方面都具有明显的区别。地球物理特征揭示郯庐断裂带深部构造,为研究重点矿产分布规律及地震灾害预报具有重要的实际意义。     

PAHs contamination and bacterial communities in mangrove surface sediments of the Jiulong River Estuary, China

Sixteen sediment samples collected from eight transects in a mangrove swamp of the Jiulong River Estuary, Fujian, China were investigated for their content of polycyclic aromatic hydrocarbons (PAHs) and the biodegradation potential of the indigenous microorganisms. The bacterial community structures in the mangrove sediments and in enrichment cultures were also investigated. The results showed that the total PAHs concentration of mangrove sediments ranged from 280 to 1074 ng g(-1) dry weight, that the PAHs composition pattern in the mangrove sediments was dominated by high molecular weight PAH components (4-6 rings), and that Benzo[ghi]perylene and Indeno[1,2,3-cd]pyrene were the most dominant at different stations. Abundant PAH-degrading bacteria were found in all the stations, the values of phenanthrene-degrading bacteria ranged from 5.85 x 10(4) to 7.80 x 10(5) CFU g(-1) dry weight, fluoranthene-degrading bacteria ranged from 5.25 x 10(4) to 5.79 x 10(5) CFU g(-1) dry weight, pyrene-degrading bacteria ranged from 3.10 x 10(4) to 6.97 x 10(5) CFU g(-1) dry weight and the benzo(a)pyrene-degrading bacteria ranged from 5.25 x 10(4) to 7.26 x 10(5) CFU g(-1) dry weight. DGGE analysis of PCR-amplified 16S rDNA gene fragments confirmed that there was a remarkable shift in the composition of the bacterial community due to the addition of the different model PAH compound phenanthrene (three ring PAH), fluoranthene(four ring PAH), pyrene(four ring PAH) and benzo(a)pyrene(five ring PAH) during enrichment batch culture. Eleven strains were obtained with different morphology and different degradation ability. The presence of common bands for microbial species in the cultures and in the native mangrove sediment DNA indicated that these strains could be potential in situ PAH-degraders.