http://www.sciencedirect.com/science/article/pii/S1674987111000879

Multiple sets of thick coal beds characterized by simple structure and shallow burial depth were developed in the Early and Middle Jurassic strata of the Ordos Basin,northwestern China.The huge reserves of this high quality coal have a high commercial value.We studied the coal’s petrologic characteristics and its maceral distribution to determine the maceral’s contribution to generation of oil and gas.The results show that the Jurassic coals in the Ordos Basin have special penological features because of the Basin’s unique depositional environment which was mainly a series of high-stand swamps in the upper fluvial system.These petrographic features are a result of the development of typical inland lakes where some sand bodies were formed by migrating rivers.After burial,the peat continued to undergo oxidizing conditions,this process generated extensive higher inertinile contents in the coals and the vitrinite components were altered to semi-vitrinite.The macroscopic petrographic types of these Jurassic coals are mainly semi-dull coal,dull coal,semilustrous and lustrous coal.The proportions of semi-dull coal and dull coal are higher in the basin margins,especially in the area near the northern margin.The numbers of semilustrous and lustrous coals increase southwards and towards the central basin.This situation indicates that different coal-forming swamp environments have major controlling effects on the coal components.Another observation is that in the Ordos" coal sequences,especially in the lower part,some sandstone beds are thick,up to 20 m with a coarse grain size.The higher fusinite content in the macerals accompanies a higher semi-vitrinite content with more complete and regular plant cell structure.The fusinite structure is clear and well preserved.After burial,the lithology of the roof and floor rocks can continue to affect the evolution of coal petrology.The sand bodies in the roof and floor exhibit good physical conditions so that pore water can maintain a long-term state of oxidation,circulation and connection to the coal.So coal components remain in an oxidation environment for a long time.Conversely,in the basin center,lacustrine facies developed and peat was rapidly covered by mudstone after burial and subsequent coal beds rapidly entered a reducing environment.As a result,abundant gelatification occurred and the vitrinite content increased.Exinite often accumulated in a specific position in the coal bed.Although the average exinite content is not high on the whole,it does significantly contribute to the total hydrocarbon generation. The exinite content has been underestimated,especially the amorphous bituminous fluid and its importance is emphasized here.The reason is that the fluid flows easily into fusinite which has strong rigidity,or flows into some fissures,where it is commonly neglected.     

东南亚国家海洋保护区发展探析

为促进区域海洋生态环境和海洋生物多样性保护,文章分析东南亚9个沿海国家海洋保护区的发展状况,提出其发展特点和困境,并针对我国开展相关合作提出建议。研究结果表明：越南、马来西亚、柬埔寨、菲律宾、缅甸、文莱、印度尼西亚、新加坡和泰国海洋保护区的法律框架、管理方式和发展现状各有不同;新冠肺炎疫情和国家政治局势在不同程度上影响东南亚海洋保护区的发展;我国可在已有框架基础上,加强与东南亚国家开展海洋生物多样性保护合作。     

A simple derivation of level spacing of quasinormal frequencies for a black hole with a deficit solid angle and quintessence-like matter

In this paper, we investigate analytically the level space of the imaginary part of quasinormal frequencies for a black hole with a deficit solid angle and quintessence-like matter by the Padmanabhan’s method (Padmanabhan in Class. Quantum Gravity 21:L1, 2004). Padmanabhan presented a method to study analytically the imaginary part of quasinormal frequencies for a class of spherically symmetric spacetimes including Schwarzschild-de Sitter black holes which has an evenly spaced structure. The results show that the level space of scalar and gravitational quasinormal frequencies for this kind of black holes only depend on the surface gravity of black-hole horizon in the range of $-1<w<-\frac{1}{3}$ , respectively. We also extend the range of w to w≤?1, the results of which are similar to that in $-1<w<-\frac{1}{3}$ case. Particularly, a black hole with a deficit solid angle in accelerating universe will be a Schwarzschild-de Sitter black hole, fixing w=?1 and ε ²=0. And a black hole with a deficit solid angle in the accelerating universe will be a Schwarzschild black hole,when ρ ₀=0 and ε ²=0. In this paper, w is the parameter of state equation, ε ² is a parameter relating to a deficit solid angle and ρ ₀ is the density of static spherically symmetrical quintessence-like matter at r=1.     

基于GPS单频软件接收机的捕获与跟踪算法实现

在分析基于软件无线电全球定位系统（GPS）接收机结构的基础上,研究了GPS单频软件接收机的捕获和跟踪算法,并基于MATLAB平台在PC上仿真了GPS单频软件接收机样机。信号捕获采用基于快速傅里叶变换（FFT）的并行码相位搜捕算法;信号跟踪联合使用超前滞后非相干延迟锁定环和科斯塔斯环的跟踪环结构。采用实测数据对信号捕获、跟踪算法进行了分析和验证。结果表明：仿真的GPS单频软件接收机具备基本的基带信号处理功能。     

近地面大气电场数据EMD方法分析

将经验模态分解(EMD)方法应用于2009年夏季近地面大气电场资料的分析,分解出雷暴和晴天天气大气电场的不同时间尺度变化分量,并提取两类天气状态下的大气电场振荡特征进行对比.结果表明:EMD方法适合应用于近地面大气电场资料的分析,雷暴天气大气电场以晴天天气大气电场作为背景场,包含了周期振荡平稳的晴天天气成分;晴天天气大气电场能量集中于长周期振荡分量,而雷暴电场能量主要是集中于短周期振荡分量.发生雷暴前,IMF(本征模态函数)1分量的中心频率会出现明显跳跃或其对应幅度明显增大的现象.利用这些特征对随机选出的38次过程进行预报效果检验,得到预警的探测概率为84.2％.     

Kinematics and age constraints of deformation in a Late Carboniferous accretionary complex in Western Junggar,NW China

The Karamay area, situated in the eastern part of Western Junggar, Southern Altaids, contains an ophiolitic mélange with ultramafic rocks, gabbro, basalt, chert and limestone, which show typical block-in-matrix structures, and coherent turbidites and tuffs. These lithological associations are interpreted as incoherent and coherent series formed in an accretionary complex. On the basis of detailed field mapping and analyses of the asymmetry of imbricate thrusts, duplexes, tilted structures, shear band cleavages, and the NW-verging inclined to overturned folds, we conclude that the overall movement in the accretionary complex was top-to-the-NW. The youngest tuff involved in the deformation contains detrital zircons that have a U–Pb age (LA-MC ICP-MS) of 308 ± 7 Ma. ³⁹Ar–⁴⁰Ar resistance furnace step-heating of amphibole separates from a diorite dike, which cuts the folded and imbricated rocks in the accretionary prism, yielded a plateau age of 307 ± 2 Ma. Consequently, the age of the deformation in the prism is tightly constrained at 307–308 Ma, implying that the deformation occurred in an extremely short time-span during SE-ward subduction. Combined contemporaneous occurrence of Baogutu adakite, high-Mg, Sr-enriched and Y-poor dioritic dikes, Miaoergou charnockite, and Maliya mafic rocks, we further suggest the accretionary complex was cut by near-trench volcanic rocks and plutons possibly due to interaction with a spreading ridge.     

Sediment characteristics in the North Branch of the Yangtze Estuary based on radioisotope tracers

Nuclide-specific activity and sediment grain size were analyzed at locations along the North Branch of the Yangtze (Changjiang) Estuary. The spatial distributions of various radioisotopes are presented, along with the sources and applications of these nuclides for studies of the aquatic environment. The specific activities of sediment radionuclides in the North Branch increase toward the ocean, indicating that the sediment is transported from the downstream side of the estuary into the North Branch. The ²²⁶Ra/²²⁸Ra ratio agrees well with the observed results and can be used to identify trends in erosion and accretion in the North Branch.     

湖北省区域经济差距及其变化的产业分解

基于人均GDP基尼系数及其变化的结构分解,对湖北省区域经济差距的动态变化、产业构成进行了深刻的分析,揭示了20世纪90年代中期以来该省17个地市州之间人均GDP差距及其变化的动力机制。结果表明,非农产业是湖北省区域经济差距的决定性因素,而非农产业尤其是第二产业地理集中程度的提高又是推动湖北省区域经济差距扩大的主导性因素。缓解湖北省区域经济差距的现实选择并不仅仅局限于加快落后地区非农产业发展,还应该促进生产要素流动,推动人口向工业化程度高的地区集中,降低湖北省生产与人口地区分布的不一致性。     

Re–Os Isotopic Age of the Hongqiling Cu–Ni Sulfide Deposit in Jilin Province,NE China and its Geological Significance

The Hongqiling Cu–Ni sulfide deposit in central Jilin Province is located in the eastern part of the Central Asian Orogenic Belt. Rhenium and osmium isotopes in sulfide minerals from the deposit are used to determine the timing of mineralization and the source of osmium, and ore metals. Sulfide ore samples have osmium and rhenium concentrations of 0.28–1.07 ppb and 2.39–13.17 ppb, respectively. Ten analyses yield an isochron age of 223 ± 9 Ma, indicating that the Cu–Ni sulfide deposit in the area formed in the Triassic. The initial ¹⁸⁷Os/¹⁸⁸Os ratio is around 0.295 ± 0.019 (MSWD = 1.14) and the δ³⁴S values of sulfide ores vary from ?1.50 to +3.00‰. These data indicate that the mineralizing materials were derived mainly from a mantle with some quantities of crustal components introduced into the rock‐forming and ore‐forming systems during mineralization and magmatic emplacement.     

高校地理学科“可持续发展”课程思政教学实践探索

国内众多高校的地理学科都开设了“可持续发展”相关课程,可持续发展教育是我国地理学科关注的重要议题。可持续发展思想中蕴含大量的思政元素,将其知识体系中的思政元素融入专业知识,有利于培养学生的辩证思维能力,发挥学科课程的育人功能。本文以“可持续发展基础”教学实践为例,明晰可持续发展相关课程特有的思政教学优势,结合课程思政教学的思路和实践,探索思政教学方法,落实思政教学策略,以期增强高校专业课程教学过程中的思政教育作用。