Detection of tannins in modern and fossil barks and in plant residues by high-resolution solid-state C nuclear magnetic resonance

Bark samples isolated from brown coal deposits in Victoria, Australia, and buried wood from Rhizophora mangle have been studies by high-resolution solid-state nuclear magnetic resonance (NMR) techniques. Dipolar dephasing ¹³C NMR appears to be a useful method of detecting the presence of tannins in geochemical samples including barks, buried woods, peats and leaf litter. It is shown that tannins are selectively preserved in bark during coalification to the brown coal stage.     

Spectroscopic and Chromatographic studies of organic carbon in Recent marine sediments from the Peruvian Upwelling Zone

Early diagenesis of organic matter in sediments from two sites in the Peruvian Upwelling Zone (12°05′S, 77°39′W; 15°17′S, 75°24′W) has been studied by observing changes in the total organic carbon and lipid and humin fractions with depth. Transformations of the total carbon and humin fraction have been characterized by conventional and time-dependent solid state NMR techniques, while lipid diagenesis was monitored by measuring the concentration of sterols in the same sedimentary horizons. Both the quantity of total sterols and the relative abundances of individual sterols vary with sampling location, suggesting a difference in the input of biomass to the sediments at the two sites. Total sterol concentrations decrease with depth at both sites, but the loss of sterols occurs much more slowly at the more anoxic northern site, where sedimentation rates and organic carbon contents are approximately twice those at the southern site. ¹³C-NMR spectra of the total organic carbon and the humin fraction suggest that humin-like compounds are an original component of the sedimentary biomass, and dipolar-dephased spectra of the humin residue indicate that diagenetic alterations of the humin fraction are occurring even in these very young sediments. Conventional and time-dependent spectroscopic data support the hypothesis that humin formation results from selective preservation of microbially-resistant biopolymers which are an original component of the sedimentary biomass combined with loss of certain labile compounds.     

Polycyclic aromatic hydrocarbons in Australian coals. I. Angularly fused pentacyclic tri- and tetraaromatic components of Victorian brown coal

Analysis of the tri- and tetraaromatic hydrocarbon fractions of a brown coal sample from the Latrobe Valley, Victoria, Australia indicate the predominance of pentacyclic hydroaromatic components. Many of these have not been previously reported in the literature, but are obviously diagenetically related to triterpenoids naturally occurring in the biosphere. The components whose molecular structures have been confirmed, together with those for which tentative structural assignments are given, offer strong support for a theory of progressive diagenetic aromatization of C-3 oxygenated triterpenoids, commencing from ring A. Other compounds present in smaller amounts suggest that 1,2-methyl shift reactions also occur prior to or during aromatization. There is a notable absence of polycyclic aromatic hydrocarbons (PAH's) which can be diagenetically related to the steroid or extended-side-chain hopane skeletons.     

The trouble with nature: Ambivalence in the lives of urban Australian environmentalists

The number and range of contests over the social production of nature is growing. Much environmentalist discourse, however, continues to appeal for unequivocal scientific support on clearly demarcated issues of pure, a-social nature. This paper explores the question of how participants in environmental movements view this demarcation in the context of their own lives. After introducing scholarly critique of dualistic ideas of nature and the ambivalence characteristic of environmentalist conceptions of nature, the paper draws upon a qualitative study with environmentalists in the Australian cities of Melbourne, Perth and Hobart. Inquiring into the interplay of discourse of nature and everyday worlds, interviews revealed a complex interdependence of dualistic and non-dualistic understandings of nature. This ecology of ideas was especially evident in spatial imaginaries of nature. Scientific terminology, social disaffection and pessimism were associated with abstract and mutually exclusive conceptions of society and nature. Reflections on personal experience, however, indicated more flexible and hopeful negotiations in everyday liminal spaces offering ‘the best of both worlds’. It is concluded that environmentalist resistance to dismantling of conceptual boundaries between society and nature may often stem not from failure to appreciate socionatural complexity, but from a strongly felt sense that the self can only truly be found in nature.     

Possible chemical structures and biological precursors of different vitrinites in coal measure in Northwest China

Chemical structure of Jurassic vitrinites isolated from the coals in basins in NW China have been checked using solid state ¹³C NMR and flash pyrolysis-GC/MS. Study shows some Jurassic collodetrinites are rich in aliphatic products in pyrolysates, consisting with the high amount of methylene carbon in ¹³C NMR spectra. In contrast, pyrolysates of Jurassic collotelinites are rich in phenols and alkylbenzenes. Also one Pennsylvanian and one Permian vitrinite selected from the Ordos basin, NW China have been checked for comparison. The proportion of aliphatics is low in pyrolysates, and aliphatic carbon peak in ¹³C NMR spectrum of Permian vitrinite is mostly composed of gas-prone carbons compared with collodetrinites in those Jurassic basins. But both pyrolysis and ¹³C NMR data shows the Pennsylvanian vitrinite is not only gas-prone but also oil-prone. Relatively high proportion of long chain aliphatic structure of some Jurassic vitrinite in Junggar, Turpan-Hami basins may be due to the contribution of liptodetrinites, which may be included during the formation of vitrinites. And it seems that suberinite is the most possible precursor of long chain aliphatics in the structure of Jurassic collodetrinite.     

Controls on the nature and distribution of an alga in coal mine-waste environments and its potential impact on water quality

 A dominant non-bacterial microorganism that may strongly impact environmental conditions in acid mine drainage at several Indiana coal mine sites is a single-celled protozoan, Euglena mutabilis. Field data suggest E. mutabilis has high tolerance for elevated total dissolved solids (TDS), to 18 g/l, and acid conditions to pH 1.7. Distribution is restricted to unmixed effluent pH<4.6, with prolific growth between pH 3.0 and 3.5. Additional factors influencing E. mutabilis include preference for areas with lower mineral/colloidal precipitation rates and a stable substrate of iron-rich precipitates. Initial studies indicate that in areas of prolific growth it contributes to oversaturation of dissolved oxygen by up to 200%. The presence of small orange intracellular crystalline-like structures, similar in color to iron oxyhydroxides, suggests that E. mutabilis may be sequestering iron, and possibly other metals. Further work is needed to determine if E. mutabilis contributes to natural mitigation of poor water quality at these and other coal mine sites. Received: 13 January 2000 · Accepted: 2 May 2000     

内蒙古商都白云鄂博群小壳化石的发现及其意义

根据研究清河镇化石群提供的信息,在内蒙古商都五道湾地区白云鄂博群阿牙登组下部首次发现梅树村阶小壳动物化石,内含软舌螺类、似软舌螺类、齿形壳类、棱壳类、卡门壳类等８属８种（含１相似种,２未定种）及大量海绵骨针,共计２０００余件。确定白云鄂博群的地质时代为震旦纪一寒武（奥陶）纪。再次证明了清河镇化石群的存在;验证了氢氟酸法是提取浅变碳酸盐岩中化石的有效方法;并提出加里东褶皱带的新设想。     

煤层气在储层中的流态分布特征

煤层气流态是表征煤层气在介质中流动难易程度的阶段量。综合前人研究经验,借助煤层气流态方程推演解译,对煤层气流态界限进行了划分,总结出煤层气在储层中的流态按渗透率k和运移距离L分布的规律。这为煤层气合理开发方案的制定具有一定的现实意义。     

潞安矿区煤储层压力低的原因分析

针对潞安矿区煤储层压力普遍偏低的情况，根据该矿区埋藏－热演化史和流体状态方程，对储层压力的变化史进行了分析计算，认为煤储层温度降低所引起的流体体积收缩是造成储层低压的主要原因，储层温度降低与异常古地热场恢复正常和构造抬升有关。     

煤中氮的赋存状态与含量分布研究进展

综述了煤中氮的赋存状态与氮含量的分布特征方面的研究现状及存在问题。认为,煤中的氮几乎全部以有机物的形式存在,其赋存状态主要有4种类型：吡咯型氮（N-5）、吡啶型氮（N-6）、季氮（N-Q）和氮氧化物（N-X）,且这四种含氮官能团的分配比例受煤阶和煤热解程度的影响。煤中氮的质量分数一般在0.5%~2.5%,其变化与煤级、成煤期、沉积环境、原始成煤植物、煤岩组成及岩浆侵入等因素有关。目前有关影响氮含量变化因素的研究主要集中在探讨氮的含量与煤级的关系上,并认为氮的含量随煤级升高而增大,但在煤化作用后期迅速降低。有关氮的研究可丰富煤的元素地球化学研究,并为煤的环境污染治理提供更多的科学依据。     

Sulfide oxidation in brown coal overburden and chemical modeling of reactions in aquifers influenced by sulfide oxidation

With a mean annual flow of 5.9×10¹¹m³yr^–1 and sediment load of 1600x10¹²gyr^–1 the Ganges river ranks second and third, respectively, in terms of water flow and sediment load among the world's rivers. Considering the enormous sediment transport by Ganges to the Bay of Bengal, a study was conducted on the size distribution and mineral characteristics of the suspended sediments of the Ganges river and is reported here. Most of the sediment load has a size range between <4–5.75 ). The sediments are mostly medium to coarse silt and are poorly sorted. Mica dominates among the clay minerals, followed by chlorite, vermiculite, kaolinite, and smectite. Due to differences in geology, smectite becomes a major clay mineral in downstream rivers. At Calcutta, the clay mineral transport in millions of tons per year is 18,464, 8000, and 2147, for mica, smectite, and chlorite, respectively.     

单轴加载煤孔裂隙各向异性核磁共振特征

为了研究煤孔裂隙各向异性,进一步揭示煤微观结构及物性特征。选取平顶山矿区八矿煤样,采用核磁共振（NMR）方法,对比分析单轴加载前后煤样的横向弛豫谱（T₂）特征和核磁成像（MRI）特征。实验结果表明,煤的T₂谱特征具有显著的各向异性：平行于层理且垂直主裂隙X方向T₂谱为3峰谱图,平行于层理且平行主裂隙Y方向T₂谱为双峰谱图,垂直层理Z方向T₂谱主要以单峰为主;单轴加载后煤样T₂谱面积、孔隙度减小,X、Y方向煤样孔隙变化引起的峰面积所占比例下降,裂隙变化引起的峰面积占比例上升;Z方向裂隙变化引起的峰面积占比例下降;MRI揭示出,单轴加载后平行层理方向煤样孔裂隙大部分闭合,部分裂隙产生径向变形;加载方向裂隙大部分闭合,压实效应显著。综上所述,单轴加载下,煤样各向异性特征显著,同时表明核磁共振技术是研究煤孔裂隙微观变化的有效手段。     

Regional stress and structure in relation to brown coal open cuts of the Latrobe Valley,Victoria

An interpretation of the origins of folds and joints, which affect the Tertiary Brown Coal Measures of the Latrobe Valley, leads to the proposal that the geological structures have been formed under a regional Late Tertiary NNW‐SSE compressive stress. Considerations of the pattern of measured in situ stresses and of interpreted stresses, derived from earth movements around open cuts and from earthquakes, indicate that a regional NNW‐SSE compressive stress is still in existence in the SE part of Australia at the present time.

It is proposed that the consistencies in the stress orientations reflect consistencies in the Late Tertiary to Recent global movements of the Australian plate.     

晋北中新世汉诺坝玄武岩中木化石的发现及其古气候意义

首次在晋北中新统汉诺坝玄武岩沉积夹层中发现了木化石。通过木化石的沉积环境分析,认为其为洪积扇上发育的辫状河道环境。对树木高度进行了估算,结果表明其为中等高大的乔木。结合前人对中新世中国北方孢粉、古植物、哺乳动物化石等的分析认为,中中新世晋北左云一带处于湿润的森林,且已向较干旱的疏林草原环境过渡,季节性降水导致的洪水携带大量砂砾将平缓地带的乔木迅速埋藏。这一发现,对于研究中新世时中国北方古气候变化及植物地理区系演化具有重要意义。     

The use of air decks in production blasting in an open pit coal mine

The influence of air deck blasting on blast performance and blast economics and its feasibility has been studied in the production blasting of soft and medium strength sandstone overburden rocks in an open pit coal mine in India. The air deck blasting technique was very effective in soft and medium strength rocks. Its main effects resulted in reducing fines, in producing more uniform fragmentation and in improving blast economics. The fines were reduced by 60–70% in homogeneous sandstones. Oversize boulders were reduced by 80% and shovel loading efficiency was improved by 20–40% in blocky sandstones. The explosive cost was reduced by 10–35% dependent on the type of rock mass. Throw, backbreak and ground vibration were reduced by 10–35%, 50–80% and 30–94% respectively. For a particular rock mass and blast design environment, air deck length (ADL) significantly influenced the fragmentation. ADL as represented by air deck factor (ADF) in the range of 0.10–0.35 times the original charge length (OCL) produced optimum results. ADF beyond 0.35 resulted in poor fragmentation and in inadequate burden movement.     

我国煤炭主体能源安全高质量发展的理论技术思考

【目的】为研究多源煤基固废胶结充填体的力学特性及变形破坏规律,选择5种典型煤基固废,开展了煤基固废胶结充填体(Coal-Based Solid Waste Cemented Backfill,CBSWCB)的单轴压缩、声发射响应及微观结构测试试验。【方法】分析了CBSWCB单轴抗压强度的影响因素和交互作用,建立了基于交互作用的抗压强度影响因素四维空间可视化模型,结合CBSWCB的声发射及微观结构特征,阐明了单轴压缩条件下的力学演化特征及宏观变形破坏规律,从微观角度进一步论证了CBSWCB承载过程中水化反应机理及宏细观联系。【结果和结论】试验结果表明：(1)单轴抗压强度的主要影响因素是质量分数,而炉底渣掺量的影响程度最小。(2)单轴压缩下CBSWCB的宏观变形破坏由塑性、弱劈裂破坏逐渐向脆性、剪切破坏转化。(3) CBSWCB试件声发射参数演化可以分为上升期、平静期、活跃期、稳定期,声发射累计振铃计数曲线呈现明显的“阶梯状”增长,累计振铃计数在上升期和平稳期内缓慢增加,在活跃期急剧增加,在稳定期逐渐趋于平缓。(4)水泥掺量偏低以及多源煤基固废充填材料属性差异导致水化反应程度有限,水化产物数量较少是CBSWCB单轴抗压强度普遍偏低的主要原因。研究结果可为多源煤基固废用于充填开采提供一定参考依据。

     

The role of shear strain in the graphitization of a high-volatile bituminous and an anthracitic coal

A ‘soft’ carbon-based high-volatile bituminous (R_{o max}=0.68%) coal and a ‘hard’ carbon-based Pennsylvania anthracite (R_{o max}=5.27%) were deformed in the steady state at high temperatures and pressures in a series of coaxial and simple shear deformation experiments designed to constrain the role of shear strain and strain energy in the graphitization process. Tests were carried out in a Griggs-t type solid (NaCl) medium apparatus at T=400–900°C, constant displacement rates of 10^-5−10^-6 s⁻¹, at confining pressures of 0.6 GPa (coaxial) or 0.8 and 1.0 GPa (simple shear). Coaxial samples were shortened up to 50%, whereas shear strains up to 4.9 were attained in simple shear tests. Experiments lasted up to 118 h. Deformed, high-volatile bituminous coal was extensively coked and no correlation between strain and R_{o max}, bireflectance or coal texture was observed in any samples. With increasing temperature, R_{o max} and bireflectance increase in highly anisotropic, coarse mosaic units, but remain essentially constant in the fine granular mosaic, which becomes more abundant at higher temperatures. Graphite-like reflectances are observed locally only in highly reactive macerals and in pyrolytic carbon veins. The degree of molecular ordering attained in deformed bituminous coal samples appears to be determined by the heating-pressurization path rather than by subsequent deformation.Graphitization did not occur in coaxially deformed anthracite. Nonetheless, dramatic molecular ordering occurs at T>700°C, with average bireflectance values increasing from 1.68% at 700°C to 6.36% at 900°C. Anisotropy is greatest in zones of high strain at all temperatures. In anthracite samples deformed in simple shear over the 600–900°C range at 1.0 GPa, the average R_{o max} values increase up to 11.9%, whereas average bireflectance values increase up to 10.7%. Bireflectance increases with progressive bedding rotation and, thus, with increasing shear strain. Graphitization occurs in several anthracite samples deformed in simple shear at 900°C. X-ray diffraction and transmission electron microscopy of highly anisotropic material in one sample confirms the presence of graphite with d₀₀₂=0.3363 nm. These data strongly suggest that shear strain, through its tendency to align basic structural units, is the factor responsible for the natural transformation of anthracite to graphite at temperatures far below the 2200°C required in hydrostatic heating experiments at ambient pressure.     

The nature and fate of natural resins in the geosphere XIII: a probable pinaceous resin from the early Cretaceous (Barremian), Isle of Wight

Terpenoid resin is produced by all families and most genera of the order Coniferales (the conifers), and the distribution of terpenes present in most conifer resins is characteristic of the originating family. Analyses of early Cretaceous (Barremian) amber (fossil resin) from the English Wealden, Isle of Wight, southern England, by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), indicate a terpene distribution dominated by abietane- and labdane-type terpenes. Similar distributions are observed in some species of the extant family Pinaceae. The Pinaceae are well represented within the Wealden deposits of southern England, by only one (known) species, Pityites solmsii (Seward) Seward, whereas the macro-fossil record of these deposits is dominated by the extinct conifer family Cheirolepidiaceae, for which no resin chemistry has been reported. By analogy with modern materials, it is probable that the ambers found in these deposits are derived from an extinct member of the Pinaceae, but given the absence of evidence concerning the chemotaxonomy of the Cheirolepidiaceae, this family cannot be excluded a priori as a possible paleobotanical source. These ambers may therefore be assigned to either the Pinaceae or to the Cheirolepidiaceae. These samples are the oldest ambers to date to yield useful chemotaxonomic data.     

西藏改则地区班公湖-怒江结合带内上三叠统的发现及其地质意义

三叠系在班公湖-怒江结合带两侧仅有少量露头。早三叠世是怒江洋盆初始演化的开始,由于晚二叠世-早三叠世大规模的海退持续和地壳的抬升,地层遭受剥蚀,整个班公湖-怒江结合带内缺乏完整的三叠系地层系统,对怒江洋的演化缺乏完整的物质记录。此次有古生物化石依据的上三叠统的发现,为探讨洋盆的演化提供了较好的依据,也为区域地层对比、地层格架建立、古环境分析等提供了基础资料。     

青藏高原尼玛盆地东部古近系昆虫化石的发现及其对古气候的指示

藏北尼玛盆地自白垩纪以来沉积了巨厚的陆相碎屑岩夹灰岩地层,由于缺乏生物化石证据,其地层时代一直存在较大的争议。最近,在尼玛盆地东部赛布错一带的细碎屑岩夹灰岩地层中发现大量的昆虫、鱼类和植物化石。昆虫化石主要为伦坡拉大黾蝽Aquarius lunpolaensis,与伦坡拉盆地达玉地区和尼玛盆地西部江弄淌噶地区报道的种属形态特征基本一致,显示该套地层为晚渐新世丁青湖组沉积,而不是竟柱山组或牛堡组。另外,伦坡拉大黾蝽主要生活在温暖湿润的低海拔地区,结合近年在青藏高原中部伦坡拉盆地和尼玛盆地晚渐新世地层中发现的热带-亚热带鱼类和大植物化石组合,指示青藏高原腹地在晚渐新世为温暖湿润的低地环境,而不是过去认为的高寒气候。