Heat flow and its coalbed gas effects in the central-south area of the Huaibei coalfield, eastern China

Based on an analysis of the present geo-temperature field and the thermal conductivity (K) of 62 samples from the central-south area of the Huaibei coalfield in eastern China, we calculated the heat flow and plotted its distribution map. The results show that the average heat flow in the research area is about 60 mW/m2. It is different from other major energy basins in the North China Plate, but has close relationship with the regional geology and the deep geological setting. The heat flow is comparatively ...     

Accuracy assessments and uncertainty analysis of spatially explicit modeling for land use/cover change and urbanization:A case in Beijing metropolitan area

Spatially explicit modeling plays a vital role in land use/cover change and urbanization research as well as resources management;however,current models lack proper validation and fail to incorporate uncertainty into the formulation of model predictions.Consequently,policy makers and the general public may develop opinions based on potentially misleading research,which fails to allow for truly informed decisions.Here we use an uncertainty strategy of spatially explicit modeling combined with the series stat...     

Comparative Studies on the Harm Characteristic of Hot-dry wind and High Temperature Heat Waves

This paper summarized six aspects such as the harm characteristics, type and index, climatic characteristics, causes, responding to globe changes, protecting technology and answering tactics of hot-dry wind and high temperature heat wave. There is distinction and relationship between hot dry wind and high temperature heat wave. This includes that both of hot-dry wind and high temperature heat wave belong to serious shorter time scale weather disasters. Lower humidity and higher temperature are their main characteristics. The two causes of abnormal circulation characteristics and impacts of the disasters from climate change are basically the same. The disasters may occur in the same area during the same period. Arid season is helphul for their development and aggravation damage. There are differences on harm characteristics, type and index, climatic characteristics, protecting technology and answering tactics in this two weather disasters in that the high temperature heat wave is the comprehensiveness meteorological disasters and dry-hot wind is the agrometeorological disasters.     

The influence of biodegradation on resins and asphaltenes in the Liaohe Basin

Asphaltenes are traditionally considered to be recalcitrant to microbial alteration. Resins and asphaltenes of seven biodegraded oils extracted from reservoir cores of two columns (Es3 and Es1) of the Lengdong oilfield in the Liaohe Basin, NE China, were studied to test this hypothesis. Elemental (C, H, N, O, S) and isotopic compositions (δ¹³C and δ¹⁵N) were measured, FT-IR was used to study the oxygenated functionalities of both resins and asphaltenes, and Py–GC–MS was used to elucidate how alkyl side chains of asphaltenes were altered during biodegradation. We conclude that the products of biodegradation, such as carboxylic acids, phenol and alcohols, may not only contribute to the resin fraction of crude oils, but also are linked with functionalities of resins and asphaltenes. The amount of asphaltenes increases because some resin molecules are enlarged and their polarity increased such that they can be precipitated by hexane as newly generated asphaltenes. Thus, the hydrocarbons that are progressively consumed during biodegradation can pull the δ¹³C of asphaltene fraction closer to the δ¹³C of the altered resins and hydrocarbons that were consumed.     

Chronology and Sources of Mesozoic Intrusive Complexes in the Xuzhou-Huainan Region, Central China: Constraints from SHRIMP Zircon U-Pb Dating

SHRIMP zircon U-Pb dating in the Liguo and Jiagou intrusives indicates that they were formed at -130 Ma in the Early Cretaceous. Most inherited zircons in the Liguo intrusive were formed at 2509±43 Ma. Most inherited and detrital zircons in the Jiagou intrusive were formed at -2500 Ma, -2000 Ma and -1800 Ma. The SHRIMP zircon U-Pb dating in two gneiss xenoliths from the Jiagou intrusive yields the ages of 2461±22 Ma and 2508±15 Ma, respectively. The dating results from inherited and detrital zircons in the intrusives and the gneiss xenoliths imply that the magmas could be derived from the partial melting of the basement of the North China Block (NCB). The magmatism is strong and extensive in the periods from 115 to 132 Ma, which is of typical bimodal characteristics. It is suggested that the lithospheric thinning in the eastern North China Block reached its peak in 115-132 Ma.     

湖北宜昌地区下奥陶统生物礁古生态学研究

宜昌地区下奥陶统主要为一套台地相碳酸盐沉积,间夹页岩,其中的特征沉积为发育有较多的生物礁。造礁生物主要有海绵类、瓶筐石类、有柄棘皮类、苔藓虫及蓝细菌和Pulchrilamina等。在下奥陶统含礁层系中识别出四种生物相：(1)壳类生物相：发育有Tritoechia-Pelmatozans群落和Tritoechia-Pomatotrema群落;(2)礁生物相：包括Batostoma群落、Calathium--Archaeoscyphia群落、Pelmatozoans--Batostoma群落、Archeoscyphia群落和Calathium--Cyanobacteria群落;(3)静水生物相：发育有Acanthograptus--Dendrogptus群落和Yichangopora群落;(4)异地生物相：产有异地埋藏群,即Nanorthis--Psilocephlina埋藏群。含礁层系存在四个海平面变化旋回,生物礁的发育明显受海平面的升降速率与容纳空间增长速率的控制。生物礁多形成于高海平面时期。由于本区的海平面在上升过程中存在多个次一级旋回,致使生物礁具有数量多、分布广以及厚度薄和规模小等特点。造礁群落存在着演替和取代两种形式,前者有利于生物礁的发育,后者则表现为礁体的衰亡。     

宽频地震计及倾斜、重力仪对长周期波动信号的综合观测

报道了在武汉华中科技大学地震与固体潮试验站的同一观测平台上,用数字宽频地震计、倾斜仪及重力仪对长周期地震波动信号的综合观测结果,以及各观测的对比和分析。近3年来,不同的观测仪器同时观测到了几十个形态一致、信号较弱而且成分复杂、持续时间大多约为2——3天的异常波（震颤）。分析表明,这些异常震颤中的一部分由来自西太平洋进入中国大陆及近海的台风产生,其信号强弱主要与台风运动中心进入中国大陆近海后与观测点之间的距离,以及风速大小这两个因素密切关联。另外,还有一部分异常震颤信号的产生原因不明。频谱分析结果显示,与平常的背景噪声信号相比,异常震颤信号的成分较为丰富, 除了3——5 min周期的信号外,还含有20——30 min,甚至一小时以上的长周期信号。我们以多种观测仪、长时间的连续观测结果表明,这种震颤信号是真实的和普遍存在的。其产生原因和机制还有待更广泛和深入的研究。      

人工边界高频振荡失稳机理的一点注记

进一步完善了人工边界高频振荡失稳机理的解释. 解析证明了对于一维波动模型的离散模型, 当人工波速大于1.5倍的离散空间步距与时间步距的比值时, 则在某一高频段内, 其稳态波动解在人工边界上反射系数的模大于1的命题. 在此基础上对失稳的高频段作了进一步的讨论, 揭示了高频振荡失稳发生于对波动数值模拟无意义的高频段.      

Preliminary Study on the Dynamic Variations of the Surface Thermal Flux before and after the M_S5.7 Earthquake of 2005 in Jiujiang City,Jiangxi Province

The temporal and spatial variations of surface latent heat flux （SLHF） and diagnostic air temperature at 2m before and after the Ms5.7 earthquake occurring on November 26, 2005 in the area between Ruichang City and Jiujiang City, Jiangxi Province are summarized in this paper. It is found that before the earthquake significant SLHF anomalies and air temperature anomalies occurred in the epicentral area and its vicinity. The air temperature anomalies appeared from the 2nd to the 13th of November, 2005 and were concentrated at the epicentral area and in its southern part. Then two days later, that is, from the 4th to the 15th of November 2005, significant SLHF anomalies occurred in the epicentral area and to its northern area where many lakes are distributed along the active faults. During the anomalous period, the SLHF and air temperature at 2m exceeded the sum of average daily value over 26 years and 1.5 times of its mean square deviation. Both anomalies had maintained for 12 days with a peculiar distribution related to the tectonic active zone. It is considered that both of air temperature anomalies and SLHF anomalies are correlated to the movement of thermal flux from underground prior to earthquake. SLHF anomalies occurred over wide regions covered with abundant water, whereas air temperature anomalies occurred over land.     

Modeling transient and long-term postseis-mic deformation: A case study of 1995 M_w9.5 Chile earthquake

In this paper, we firstly use finite element method (FEM) with Burgers model to simulate the postseismic viscoe-lastic relaxation taking 1960 Chile earthquake as an example. The postseismic deformation modeled with Burgers model includes co-seismic deformation, transient postseismic deformation and long-term postseismic deformation. So if we apply Burgers model to calculate postseismic deformation of 1960 Chile earthquake, there is no discrep-ancy phenomenon due to different durations of postseismic deforma...