Spatial distribution of trace elements associated with organic carbon along the Beiyun River basin,Beijing,China

Pollution resulting from terrestrial and aquatic trace elements has become a severe problem across the world. Organic carbon(OC) content has a high affinity for metallic contaminants and it acts as a significant sink for trace elements. The decomposition of OC content directly influences the bioavailability of trace elements. The decomposition of OC content and OC distribution vary spatially, these processes affect the release of trace elements and need further research. In the current study, se...     

塔里木盆地西部白垩纪—古近纪海相地层框架及对重大地质事件的记录

塔里木盆地西部白垩纪—古近纪发生了大规模的海侵事件,形成一个喇叭状向西开口的海湾,该海湾属于东特提斯洋的一个分支。该地区白垩纪—古近纪海相地层记录了东特提斯洋演化和一系列重大地质事件,具有重要的研究价值,但对其地层的研究仍相对薄弱,对重大地质事件的研究还不够深入。本文拟通过详细的岩石地层、生物地层和其他地层方法,完善地层划分与对比框架,并在此基础上讨论Cenomanian/ Turonian界线大洋缺氧事件(OAE2)、白垩纪/古近纪界线(K/Pg)、古新世—始新世极热事件(PETM)、特提斯海进与海退等一系列重大地质事件。塔里木盆地白垩纪—古近纪海相或海陆过渡相地层自下而上为克孜勒苏群、库克拜组、乌依塔克组、依格孜牙组、吐依洛克组、阿尔塔什组、齐姆根组、盖吉塔格组、卡拉塔尔组、乌拉根组和巴什布拉克组,上述地层中含有丰富的有孔虫、介形虫、钙质超微、沟鞭藻、孢粉、双壳类、腹足类等化石,以及少量菊石、腕足类、海胆和鲨鱼牙齿等化石。综合的生物地层和年代地层研究表明,克孜勒苏群的时代为早白垩世Barremian-Albian期,库克拜组—依格孜牙组的时代为晚白垩世Cenomanian-Maastrichtian期(Cenomanian/Turonian界线可能位于库克拜组三段),吐依洛克组的时代为白垩纪—古近纪过渡期;阿尔塔什组的时代为古新世早中期,齐姆根组为古新世晚期—始新世最早期,盖吉塔格组—乌拉根组的时代为中始新世中晚期,巴什布拉克组的时代为晚始新世,但不排除最上部进入渐新世早期。塔里木盆地的海侵开始于克孜勒苏群中上部沉积期(Albian晚期—Aptian早期),但规模很有限,大规模的海侵始于晚白垩世Cenomanian早期;从晚白垩世—古新世,共经历了5次大规模的海侵—海退事件;大约41 Ma前后,海水退出盆地南部的昆仑山山前,34 Ma前后,海水退出盆地北部的天山山前。上述海侵—海退事件可能受构造和全球海平面变化的双重影响,但构造事件对海侵的启动和结束可能更具决定性的影响。阐述了塔里木盆地西部白垩纪—古近纪海相地层所记录的OAE2、K/Pg界线、PETM和特提斯海侵—海退等事件,其中笔者及团队第一次在塔里木盆地西部齐姆根组中所发现和报道的PETM事件,将有助于揭示全球近岸地区PETM的特征和生物-环境响应。在未来的研究中,需要进一步厘清塔里木盆地西部地层序列,建立更加精细的生物地层和年代地层框架,加强对PETM和特提斯海侵—海退等重大地质事件的研究。     

Effect of Saline Sludge on Anaerobic Digestion of Kitchen Waste for Methane Generation: Modeling and Fertilizer Recovery

A comparative study of methane recovery by co-digesting kitchen waste and saline sewage sludge is performed to evaluate its feasibility for waste minimization. The experiment is performed at 37 °C having a mixing speed of 100 rpm and pH of 6.49–7.5 in anaerobic mixed batch reactors. The higher salinity level of the saline sewage sludge reduces the degradation rate of kitchen waste causing an enhancement in soluble chemical oxygen demand by 133% compared with 280% when co-digesting with the non-saline sample. The inhibitory behavior is in line with the low volatile solid elimination efficiency of 31% of saline against 55% of non-saline sludge. The Gompertz modeling, based on the outcomes, fits the cumulative methane generation trends quite well, with a strong correlation coefficient (>0.994). Besides, use of the non-saline sludge results in three times more methane production than the saline sample digestion. Sludge recovery is 0.07 m³ sludge m⁻³ wastewater, and water recovery is 0.84 m³ m⁻³ wastewater. The liquid produced from the fermentation of the slurry can be used for irrigation as well as fertilization. Kitchen waste co-digestion with both sludge samples has been proven to be a practical method for exploiting the extra digestion capacity of wastewater treatment plants currently in operation, but it is more practical for non-saline sludge.     

GIS技术在城市地下水重金属浓度识别与分级中的应用（英文）

Groundwater is the most appropriate and widely used source of drinking water,which is increasingly threatened by pollution from industrial and agricultural activities.To check the severity of the problem,156 groundwater samples were collected from various depths(60-110 ft) of 52 different localities in Faisalabad city,the third largest metropolis in Pakistan,and analyzed for the metals(Zn,Cu,Cd,Ni,Pb,Mn and Fe) concentration in 2009.Quantification was done by using Flame Atomic Absorption Spectrophotometer technique and the results were compared with WHO standards for drinking water quality.Results showed that the levels of Cu,Mn and Fe were below the WHO standards while the concentrations of Zn,Cd,Ni and Pb were above the recommended levels of safe drinking water.Correlation analysis among the occurrence of these heavy metals revealed a highly significant and positive correlation of Mn with Zn and Fe.A significant and positive correlation of Cd was also found with Cu and groundwater depth showing that there is strong association between Cu-Cd pair and that the Cd concentration varies with depth of groundwater in the study area.Regional patterns of heavy metals occurrence were mapped using Geographical Information System(GIS) for the identification and demarcation of risk areas.The concentration maps may be used by policymakers of the city to mitigate groundwater pollution.     

Regolith thickness modeling using a GIS approach for landslide distribution analysis,NW Himalayas

Regolith thickness is considered as a contributing factor for the occurrence of landslides. Although, mostly it is ignored because of complex nature and as it requires more time and resources for investigation. This study aimed to appraise the role of regolith thickness on landslide distribution in the Muzaffarabad and surrounding areas, NW Himalayas. For this purpose regolith thickness samples were evenly collected from all the lithological units at representative sites within different slope and elevation classes in the field. Topographic attributes (slope, aspect, drainage, Topographic Wetness Index, elevation and curvature) were derived from the Digital Elevation Model (DEM) (12.5 m resolution). ArcGIS Model Builder was used to develop the regolith thickness model. Stepwise regression technique was used to explore the spatial variation of regolith thickness using topographic attributes and lithological units. The derived model explains about 88% regolith thickness variation. The model was validated and shows good agreement (70%) between observed and predicted values. Subsequently, the derived regolith model was used to understand the relationship between regolith thickness and landslide distribution. The analysis shows that most of the landslides were located within 1–5 m regolith thickness. However, landslide concentration is highest within 5–10 m regolith thickness, which shows that regolith thickness played a significant role for the occurrence of landslide in the studied area.     

Structural evolution of the Feda Graben area – A new model

The pre-Cretaceous basin evolution of the Feda Graben area in the vicinity of the Norwegian-Danish basin has been reconstructed utilizing geological and structural interpretation. The analysis reveals that the basin was faulted at its borders prior to the salt deposition in the Late Permian. Salt movement was initiated in Late Triassic and thick Triassic and Lower Jurassic pods were deposited in the graben area due to this movement. Salt pillows were developing along the Feda Graben bordering faults until Middle Jurassic when the pillows were collapsed. Salt diapirs within the study area preferentially occupy the crest of the Feda Graben and their occurrence is controlled by the underlying faulted topography. The diapirs were fed by salt from the central and southern parts of the basin and were developed by different processes i.e. upbuilding, downbuilding. Various raft structures were developed in the graben area hanging wall while some uplift occurred in the footwall during Mesozoic rifting. The Feda Graben area experienced rifting from Late Jurassic to Early Cretaceous. The most pronounced subsidence episode related with this rifting in the Feda Graben area took place along the eastern bounding Gert Fault. The Mesozoic rifting event is marked by a major unconformity on the seismic sections throughout the study area. Furthermore, the region experienced basin inversion in Late Cretaceous. The effects of inversion are more pronounced in the western part and along the Gert Fault. The inversion phenomenon can be properly understood only when considered together with the geometry of the Late Jurassic half-graben. Due to some inconsistencies in the previously proposed models for the development of the Feda Graben, a new conceptual model has been constructed.     

A Study of Largest Active Region AR12192 of 24th Solar Cycle Using Fractal Dimensions and Mathematical Morphology

Solar System Research - An active region (AR) of the sun is an area of strong magnetic field. Sunspots are frequently formed in an AR. Solar activity exhibits in the form of solar flares and...     

Rockburst Risk Analysis During High-Hard Roof Breaking in Deep Mines

Natural Resources Research - Mining operations continue to advance to greater depths to address the demand and supply of coal. However, deep mining occurs in complex and dangerous environments...     

Vicissitudes experienced by the oldest urban center in Bangladesh in relation to the migration of the Brahmaputra River

Bangladesh is one of the most densely populated countries in the world. There are 57 trans-frontier rivers in the country, the widest being the Brahmaputra River. The river's channels have frequently changed course, but the relationship between such river migrations and human settlement patterns has remained unstudied. In this paper, optically stimulated luminescence and radiocarbon dating techniques were applied to sedimentary and organic materials in the oldest urban center (Wari-Bateshwar) in Bangladesh. The results showed that the landscape around the urban center was dominated by floodplain and peatland facies between 7.9–7.6 and 4.7–1.6 ka, respectively. Humans occupied this area at ~3.2 ka, and manufactured delicate semi-precious gemstone beads between ~2.4 and 1.8 ka. The urban center might be the same as an important city of the Gangaridai described in historical records. Due to fluvial migration at ~1.8 ka, the area surrounding the urban center was covered by fluvial sand. Humans might have been forced to abandon the urban center, leading to the bead processing technology in Bangladesh being lost forever.     

First Record of the Belemnite Genus Hibolithes from Late Jurassic–Early Cretaceous Turbidites from Malaysia

Discovery of the remains of belemnites referred to the Hibolithes sp. from the Jurassic–Cretaceous Pedawan Formation in Sarawak, on the island of Borneo(Malaysia) comprises four fragments of belemnite rostra. The specimens are characterized by multiple fractures and vein filling. Two fragments measuring about 130 mm are relatively intact, with only part of the alveolar region missing; a third piece represents the middle part of a rostrum, and the fourth specimen is too fragmentary to be assigned to any specific part of the rostrum. Based on specimen characteristics, a Tithonian–Hauterivian age is plausible. The sedimentary succession that yielded the belemnite material comprises thick shale that reflects the Te division of Bouma sequence. The occurrence of a Hibolithes taxon in the uppermost Jurassic to lowermost Cretaceous Pedawan Formation sediments in Borneo reflects a near to global palaeobiogeographic distribution of this genus.