Rare Earth Elements Compositions and Genesis of Xinhua Large-Scale Phosphorite Deposit in Western Guizhou, China

Zhijin County in Western Guizhou is one of the most important production areas of phosphorites in China. In order to investigate genesis of the phosphorites, their REE compositions were analyzed by using inductively coupled plasma emission mass spectrometry (ICP-MS) method. For comparison, phosphorites from the Lower Cambrian black rock series in Southern China, such as Zunyi in Guizhou and Zhangjiajie in Hunan Province, were also analyzed. The analytical data show that: (1) Xinhua phosphorites possess a quite high and greatly varied total rare earth elements (ΣREE), which varying between 164.23×10-6 and 1395.01×10-6 with average of 642.54×10-6, remarkable differentiation between light (LREE) and heavy rare earth elements (HREE), and the ΣLREE/ΣHREE ratios varying between 5.04 and 6.52. The ΣREE and ΣLREE/ΣHREE ratios of the Zunyi and Zhangjiajie phosphorites are 156.69×10-6～637.41×10-6 with average of 431 75×10-6 and 3.17～6.95 with average of 4.37 respectively; (2) All the phosphorites from Xinhua, Zunyi and Zhangjiajie show remarkable negative Ce anomalies. Besides, the Xinhua phosphorites possess lower δCe, which varying between 0.26 and 0.53 with average of 0.35, while δCe of the Zunyi and Zhangjiajie phosphorites are 0.30～0.66 with average of 0.47, suggesting that all of the phosphorites are typical marine sediments deposited mainly in ancient peri-continental seas, and the depositional position of the Xinhua phosphorite might be deeper; (3) Most phosphorites from Xinhua, Zunyi and Zhangjiajie possess unremarkable positive Eu anomaly, and only a few of samples show obvious ones. The δEu varies between 0.98 and 2.4, suggesting that hot (>200 ℃) and strong reductive hydrothermal fluids might have been involved in genesis of the phosphorites; (4) The Xinhua phosphorite is relatively depleted in HREE, and LaN/NdN and δY of most samples are >1 and >1.5 respectively. Besides, there exists no correlation between δY and δCe, suggesting that the phosphorite was subjected to quite strong weathering and leaching processes, and catagenesis do not greatly modify its REE compositions.

Correlation and analysis of well-log sequence with Milankovitch cycles as rulers: A case study of coal-bearing strata of late Permian in western Guizhou

Based on the well-logging data of typical wells of Zhijin,Panxian and Weining areas in western Guizhou,the well-logging data GR of late Permian coal-bearing strata were processed and wavelet transform technique was used to carry out the sequence stratigraphy division and correlation.The study mainly focuses on the controlling effects which Milankovitch had on high frequency sequence,Milankovitch cycle can be used as a ruler of sequence stratigraphy division and correlation to ensure the scientifcity and the unity of sequence stratigraphy division.According to well-logging signal of the ideal Milankovitch cycle,the corresponding relation between the wavelet scales and the cycles is determined by wavelet analysis.Through analyzing analog signals of subsequence sets to search the corresponding relation between various system tracts and the features of time-frequency,the internal features of wavelet transform scalogram could be made clearly.According to ideal model research,features of Milankovitch curves and wavelet spectrum can be seen clearly and each well can be classifed into four third-order sequences and two system tracts.At the same time Milankovitch cycle can realize the division and correlation of stratigraphic sequence in a quick and convenient way.

Geological characteristics and co-exploration and co-production methods of Upper Permian Longtan coal measure gas in Yangmeishu Syncline, Western Guizhou Province, China

Coal measure gas(also known as coal-bearing unconventional gas)is the key field and development direction of unconventional natural gas in recent years.The exploration and evaluation of coal measure gas(coalbed methane,coal shale gas and coal measure tight sandstone gas)from single coalbed methane has greatly expanded the field and space of resource evaluation,which is of positive significance for realizing the comprehensive utilization of coal resources,maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development.For the first time,in Yangmeishu Syncline of Western Guizhou Province,the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation,identified the geological conditions of coal measure gas and found high quality resources.The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×106 m3/km2.In this area,the coal measures are characterized by many layers of minable coal seams,large total thickness,thin to the medium thickness of the single layer,good gas-bearing property of coal seams and coal measure mudstone and sandstone,good reservoir physical property and high-pressure coefficient.According to the principle of combination of high quality and similarity of key parameters of the coal reservoir,the most favorable intervals are No.5-2,No.7 and No.13-2 coal seam in Well YMC1.And the pilot tests are carried out on coal seams and roof silty mudstone,such as staged perforation,increasing hydraulic fracturing scale and"three gas"production.The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained,which has realized the breakthrough in the geological survey of coal measure gas in Southwest China.Based on the above investigation results,the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the coexploration and co-production methods,such as the optimization method of favorable intervals,the highefficiency fracturing and reservoir reconstruction method of coal measures,and the"three gas"drainage and production system,are systematically summarized in this paper.It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.

Meticulous Regionalization of Climate Suitability about Spring Potato Planting in Western Guizhou Based on GIS

[Objective] The study aimed to carry out the regionalization of climate suitability about spring potato planting in Western Guizhou on the basis of GIS technology. [Method] Based on the climatic data of 15 meteorological stations in Western Guizhou during the growing period of spring potato from March to August in 1978-2010, the regionalization indicators of climate suitability about spring potato planting were determined according to the correlation between climatic factors and meteorological yield of spring potato. Afterwards, on the basis of climitic data and corresponding basic geographical information like longitude, latitude, altitude, slope and aspect, the spatial analysis models of division indicators about spring potato planting in Western Guizhou were established by using GIS spatial overlay analysis and used to carry out the township-level regionalization of climate suitability about spring potato planting in Western Guizhou with 100 m×100 m grids. [Result] Based on the relationship between meteorological yield of spring potato and climatic factors in Western Guizhou from 1978 to 2010, eight climatic division indicators, including altitude, average temperature,>10 ℃ active accumulated temperature, precipitation and sunshine hours in the growth stage, average temperature in July, average temperature difference between day and night from July to August, and precipitation from May to July, were chosen for spring potato planting, and each indicator had three levels, namely the most suitable, suitable and sub-suitable. Meanwhile, Western Guizhou was grouped into three areas according to these indicators, including the most suitable area, suitable area and sub-suitable area, and their area accounted for 52%, 45% and 3% of total area of the whole province respectively. [Conclusion] The research could provide scientific references for the production layout and species selection of spring potato in Western Guizhou.

Analysis on Agrometeorological Conditions of Production of Winter Wheat and Rape Crops in Western Guizhou in 2019

Whole growth period of winter wheat and rape crops in western Guizhou in 2019 was from October of 2019 to early May of 2020.Using daily temperature,rainfall and sunshine hours of three national meteorological observatories(Shuicheng,Panzhou and Liuzhi)of western Guizhou,the impact of meteorological conditions on growth and development of winter wheat and rape crops was analyzed.The results showed that average temperature in whole growth period of winter wheat and rape crops in western Guizhou in 2019 was between 11.1 and 13.0℃,which was 0.4-1.6℃higher than that in the same period of common year.Rainfall was between 276.0 and 309.0 mm.When compared with that in the same period of common year,rainfall was 7%-22%less in other regions except in Panzhou(1%more).Sunshine hours was between 689.2 and 1091.2 h.When compared with that in the same period of common year,sunshine hours was 14%-26%more in other regions except in Shuicheng(equal).In growth period of winter wheat and rape crops,there was good heat condition and sufficient sunshine,and rainfall was normal and slightly less,but it was mostly sunny and rainy alternating,which was favorable for the growth of crop root.During growth period of crops,there was lighter meteorological disaster.It was clear that meteorological conditions were conducive to the growth and development of winter wheat and rape crops in 2019.

Characteristics of microbial communities in water from CBM wells and biogas production potential in eastern Yunnan and western Guizhou, China

The study of microbial communities in the produced water of coalbed methane(CBM)wells is an important aspect of microbial-enhanced methane production.Water produced from 15 CBM wells in four synclines in eastern Yunnan and western Guizhou was collected.Through the use of 16S ribosomal RNA(16S rRNA)amplicon sequencing and realtime fluorescence quantitative polymerase chain reaction(PCR),the characteristics of bacterial and archaeal communities before and after enrichment culture were studied.The methanogenic pathways of secondary biogas were discussed,and potential microbial-enhanced methane production was preliminarily evaluated.The results showed that the bacterial DNA content in uncultured produced water was low,so it is difficult to detect.After enrichment,the dominant bacteria phyla were Proteobacteria,Bacteroidetes,and Firmicutes.A total of seven phyla were detected in the uncultured produced water,and the dominant archaeal phylum was Euyarchaeota.Methanogens were the main component of archaea.The dominant archaeal genera were Methanobacterium,Methanoculleus and Methanobrevibacter.The community structure of the archaea changed noticeably after four days of enrichment culture.The relative abundance of Euryarchaeota increased to 99%in most samples after enrichment culture.It was found that there was a transition from Methanoregula to Methanobacterium within genera.The relative abundance of Methanobacterium increased,which can produce hydrogenotrophic methane.Combined with the isotopic composition of the produced water and gas,it is considered that the CBM in the Tucheng and Enhong synlines consists of a mixture of thermogenic gas and biogas.The proportion of secondary biogas in the Tucheng and Enhong synlines are estimated to range from 10.89% to 49.62%.There are mainly hydrogentrophic methanogens in the study area,and CO_(2) reduction is the main way of microbial gas production.After enrichment culture of produced water in the study area,the hydrogenotrophic methanogens were enriched.These two areas have strong potential for microbial-enhanced methane production.

Mechanism of pore pressure variation in multiple coal reservoirs,western Guizhou region,South China

Pore pressure is an important parameter in coalbed methane(CBM)exploration and development;however,the distribution pattern and mechanism for pore pressure differences in the Upper Permian CBM reservoirs are poorly understood in the western Guizhou region of South China.In this study,lateral and vertical variations and mechanisms for pore pressure differences are analyzed based on 126 injection-falloff and in-situ stress well test data measured in Permian coal reservoirs.Generally,based on the pore pressure gradient and coefficient in coal reservoirs of the western Guizhou region,five zones can be delineated laterally:the mining areas of Zhina,northem Liupanshui,northern Guizhou,northwestern Guizhou and southern Liupanshui.Vertically,there are two main typical patterns:i)the pore pressure gradient(or coefficient)is nearly unchanged in different coal reservoirs,and ii)the pore pressure gradient(or coefficient)has cyclic variations in a borehole profile with multiple coal seams,which suggests the existence of a"superimposed CBM system".The mechanism analysis indicates that coal permeability,thermal evolution stage and hydrocarbon generation contribute little to pore pressure differences in coal reservoirs in the western Guizhou region.The present-day in-situ stress field,basement structure and tectonic activity may be the dominant factors affecting lateral pore pressure differences.The sealing capacity of caprocks and the present-day in-situ stress field are significant para-meters causing vertical pore pressure differences in coal reservoirs.These results are expected to provide new geological references for CBM exploration and develop-ment in the western Guizhou region.

Trace Elements in Sphalerite from the Dadongla Zn-Pb Deposit, Western Hunan-Eastern Guizhou Zn-Pb Metallogenic Belt, South China

The western Hunan-eastern Guizhou Zn-Pb metallogenic belt is one of the important Zn-Pb mineralization regions in China.The Dadongla deposit,located in the northeast of Guizhou Province,is one of the typical Zn-Pb deposits in the region and has estimated resources more than 12 million metric tons(Mt)with an average grade of 4.11 wt%Zn+Pb.Its orebodies are hosted in the lower Cambrian Aoxi Formation dolomite,occurring as bedded,para-bedded in shape,and in conformity with the wall rock.The ore mineral assemblage is simple,dominated by sphalerite with minor pyrite and galena,and the gangue minerals are composed of dolomite,calcite with minor bitumen and barite.In view of the lack of geological and geochemical researches,the genesis of Zn-Pb ore is still unclear.Laser ablation-inductively coupled plasma mass spectrometry(LA-ICPMS)spot and mapping analyses were used to obtain sphalerite trace element chemistry in the Dadongla Zn-Pb deposit in Guizhou,China,aiming to constrain its ore genesis.The results show that sphalerite is characterized by the enrichment of Cd,Fe,Ge and Hg,corresponding with that of typical MVT deposits.Four zones were identified in the sphalerite crystal from Dadongla from the center to margin according to the color bands.in which the zone in the center,representing the early ore-stage sphalerite,is characterized by enrichment of Cd relatively,while the zone forming at late ore-stage is enriched in Ge and Hg relatively.The finding was controlled by differential leached metals content in ore-forming fluid from its source rock.Notably,critical element Ge trends to be enriched at the late ore-stage and follows a substitution of 2 Zn^2+(?)Ge^4++□(vacancy).Moreover,the calculated ore-forming temperature ranges from 79.9℃to 177.6℃by the empirical formula,which is similar to that of typical Mississippi Valley-type(MVT)deposits.Compared with the features of trace elements in sphalerite from different types of deposits,together with the geology,the Dadongla deposit belongs to an MVT Zn-Pb deposit.

Genetic relationship between unroofing of the Emeishan large igneous province and the iron-polymetallic deposit in western Guizhou, Southwestern China: Constraint from U-Pb geochronology and geochemistry of zircon

This paper reports an integrated study of in situ U-Pb geochronology and elemental geochemistry of zircons from the Xianglushan iron-polymetallic deposit in western Guizhou Province, Southwest China. Genetic relationship between this new type of deposit and unroofing of the Emeishan large igneous province(ELIP) is focused. Along with the zoning pattern in spatial distribution of diverse weathering-related deposits along the southern and southeastern margins of the ELIP, it is suggested that the genesis of the iron-polymetallic deposit was specialized by factors of coastal paleogeography in hot-humid climate, where iron-enriched laterites formed, and repetitive marine transgression-regression occurred during the Late Permian.

滇东—黔西中二叠统白云岩特征、成因及其主控因素

【目的】中国滇东—黔西地区中二叠统广泛发育白云岩。针对这些白云岩的成因,前人开展了一系列研究,并提出了多种白云岩形成机理。然而,关于镁离子的来源、白云化的主控因素等关键问题,至今仍无定论。这些问题严重制约了滇东—黔西地区的油气扩展勘探。【方法】综合利用露头、岩心和钻井等资料,对滇东—黔西地区中二叠统白云岩的分布规律、岩相学特征和地球化学特征进行了详细分析。【结果与结论】(1)研究区白云岩的形成机理为开放热对流白云化模式。白云化流体的镁离子主要来自海水,少部分来自深部热液流体;(2)白云化流体主要通过亮晶生屑石灰岩中的孔隙,以及断层和裂缝系统运移。在温度空间差异的驱动下,白云化流体沿循环流动路径运移,导致中二叠统石灰岩迅速且广泛的白云化;(3)白云岩发育的主控因素为滩相沉积和峨眉地幔柱(活动范围)。

黔西盘关向斜两翼现今地应力差异及影响因素分析

现今地应力发育特征与分布规律对煤层气高效勘探和开发具有重要指导意义,而断层、褶皱等构造对地应力分布具有显著控制作用,即便在同一褶皱内,不同部位的现今地应力也可能存在差异。以黔西盘关向斜为例,首先基于注入/压降试井数据,计算获取实测点地应力大小;然后利用测井资料,结合修正Anderson模型,计算获取盘关向斜两翼地层现今地应力大小及分布,查明盘关向斜不同部位地应力的差异性,并重点分析了地质构造与岩石力学参数对盘关向斜两翼现今地应力的控制作用。结果表明,区域地应力大小与地层弹性模量具有正相关性,与断层数量及规模呈现负相关关系。在相同深度下,储层现今地应力越大,渗透率越低,正断型应力机制影响下的煤层渗透性较逆断型的好。研究成果可以为盘关向斜煤层气勘探和开发提供基础地质参数。

Geological modeling of coalbed methane reservoirs in the tectonically deformed coal seam group in the Dahebian block,western Guizhou,China

The widely spread Carboniferous-Permian coal seam group in southern China has great potential for coalbed methane resources,but the extensively developed tectonically deformed coal seriously restricts its development.Taking the Dahebian block in western Guizhou as the study area,the geological model of coalbed methane reservoirs in the tectonically deformed coal seam group was established,and the spatial distribution pattern of model parameters was clarified by clustering algorithms and factor analysis.The facies model suggests that the main coal body structures in Nos.1,4,and 7 coal seams are cataclastic coal and granulated coal,whereas the No.11 coal seam is dominated by granulated coal,which has larger thicknesses and spreads more continuously.The in situ permeability of primary undeformed coal,cataclastic coal,granulated coal,and mylonitized coal reservoirs are 0.333 mD,0.931 mD,0.146 mD,and 0.099 mD,respectively,according to the production performance analysis method.The property model constructed by facies-controlled modeling reveals that Nos.1,4,and 7 coal seams have a wider high-permeability area,but the gas content is lower;the high-permeability area in the No.11 coal seam is more limited,but the gas content is higher.The results of the self-organizing map neural network and K-means clustering indicate that the geological model can be divided into 6 clusters,the model parameter characteristics of the 6 clusters are summarized by data analysis in combination with 6 factors extracted by factor analysis,and the application of data analysis results in multi-layer coalbed methane co-development is presented.This study provides ideas for the geological modeling in the tectonically deformed coal seam group and its data analysis.

湘西与黔东南苗族传统聚落形态对比研究——以凤凰县与雷山县为例

以湘西凤凰县和黔东南雷山县为例,通过实地调研与数据分析,从历史文化和地理环境角度出发,对湘西与黔东南苗族传统聚落的形态特征进行对比研究,主要涉及分布和布局两个方面。在分布上,以时空演变为视角,在对比湘西与黔东南苗族聚落不同时期发展变化的基础上,通过ArcGIS对空间数据的分析,对比两者聚落点在地势和整体形态上的演变。在布局上,基于聚落与环境的关系对比两者边界与形状特征,并进而分析聚落内部布局的构成要素、空间结构与建筑密度的异同。最后分析形成以上特征的原因,总结出民族源流、社会变迁、地理环境、外界防御、自然信仰五点影响因素。对比研究旨在提升两者文化标识性,进而为保护两地苗族聚落“文化基因”,避免同质化发展提供参考依据。

贵州省某三甲公立医院1093例糖尿病患者住院费用结构及西药费影响因素分析

目的:分析贵州省某三甲医院糖尿病患者住院费用及西药费影响因素,以期为减轻患者经济负担、进一步优化医保政策、提高公众防病意识提供参考依据。方法:收集该医院2022年1093例糖尿病患者信息,对住院总费用构成进行逐步回归分析,对西药费影响因素进行K-W检验分析。结果:糖尿病患者住院总费用的中位数为17158.24元,对住院总费用影响最大的费用是西药费(P<0.05),不同性别、年龄、住院天数、诊断、是否有并发症等住院西药费的差异存在统计学意义(P<0.05)。结论:该院糖尿病患者住院费用较高,可从实施临床路径管理、完善医保政策等方面控制西药费,合理控制疾病直接经济负担,并努力提高公众预防糖尿病的意识。

Geochemical characteristics of the Xuanwei Formation in West Guizhou:Significance of sedimentary environment and mineralization

The Upper Permian Xuanwei Formation widely occurs in western Guizhou,unconformably overlying the Emeishan basalts,and mainly consists of black shales.It is～170 m thick at Cuyudong Village,Weining County,West Guizhou,China,where the samples of black shale and sandy shale were collected and analyzed.The shales mainly contain SiO2,18.9%?44.1%,Al2O3,14.8%?52.8%,Fe2O3,1.0%?41.2%,LOI,3.2%?21.1%,TiO2,1.0%-6.7%,and MgO,0.2%?2.5%.The contents of all other major elements are lower than 1.0%.It is shown that the black shales have higher contents of Fe2O3 and LOI than normal shales.The siderites occurred in the black shales with higher contents of Fe2O3,which may be attributed to hydrothermal activities on seafloor.All analyzed shale samples have extremely high Ga,47.8×10-6-109.9×10-6(70.5×10-6 on average),higher than the industrial mining standard of Ga Resource Industry Standard.The total contents of rare-earth elements(REE) of 9 black shale samples vary from 213×10-6 to 1460×10-6,suggesting that these black shales are enriched in REE.The shale-normalized REE patterns display both positive and negative Ce anomalies(Ce/Ce* from 0.5 to 1.7),revealing that the Xuanwei shales were precipitated under oxic and anoxic conditions.The Rb-Sr chronological diagram of 6 shale samples in the Xuanwei Formation shows an age of 255±12 Ma.Strontium isotopic ratios(87Sr/86Sr)t0 range from 0.70635 to 0.70711,suggesting that these Xuanwei black shales might be derived from chemical weathering of the Emeishan basalts.

A preliminary study on ore-forming environments of Xianglushan-type iron deposit and the weathering mineralization of Emeishan basalt in Guizhou Province, China

Xianglushan-type iron deposits are one of the new types of iron deposits found in the Weining Area of Western Guizhou. The iron-bearing rock system is a paleo-weathered crustal sedimentary(or accumulating) stratum between the top of the Middle-Late Permian Emeishan basalt formation and the Late Permian Xuanwei formation. Iron ore is hosted in the Lower-Middle part of the rock system. In terms of the genesis of mineral deposit, this type of deposit should be a basalt paleo-weathering crustal redeposit type, very different from marine sedimentary iron deposits or continental weathering crust iron deposits. Based on field work and the analytical results of XRD Powder Diffraction, Electron Probe, Scanner Electron Microscope, etc., the geological setting of the ore-forming processes and the deposit features are illustrated in this paper. The ore-forming environment of the deposit and the Emeishan basalt weathering mineralization are also discussed in order to enhance the knowledge of the universality and diversity of mineralization of the Emeishan Large Igneous Province(ELIP), which may be a considerable reference to further research for ELIP metallogenic theories, and geological research for iron deposits in the paleo-weathering crust areas of the Emeishan basalt,Southwestern, China.

黔西与湖南寒婆坳地区煤制石墨烯结构的演化特征

石墨烯作为21世纪的战略性新兴材料,因其优异的性能受到广泛关注。研究表明煤可作为石墨烯碳源,并且煤的属性也影响石墨烯的结构特征,结合我国煤变质成因复杂、煤变质作用类型多样的特点,旨在研究不同变质作用背景对石墨烯结构的影响特征。采集黔西地区深成叠加热液变质作用6个煤样及寒婆坳地区岩浆热变质作用4个煤样,全部利用HCl-HF-HNO3酸洗方法进行处理后得到脱矿煤样,以排除矿物的影响;后使用中频感应石墨化炉对脱矿煤样进行2800℃高温处理后得到煤基石墨样品;最后利用改进的Hummers氧化还原法对煤基石墨进行氧化、超声剥离、还原处理,得到石墨烯样品;用于测试样品微晶尺寸、空间形态等信息的X射线衍射(XRD)对脱矿样、煤基石墨、石墨烯进行表征并得到相关结构参数,用于测试样品缺陷、完整性的拉曼光谱(Raman)对脱矿样、煤基石墨、石墨烯样品进行表征并得到相关参数,用于观察样品微观表面形貌的透射电镜(TEM)对石墨烯样品进行表征并得到图像。实验及表征结果:透射电镜(TEM)得到的图像表明2种变质类型的煤均可制备出3~5层的石墨烯层片。X射线衍射(XRD)和拉曼光谱(Raman)得到的相关参数表明煤的变质程度越高,对应的煤基石墨样品石墨化度越高,对应石墨烯样品的微晶结构片层越大、缺陷更少。以X射线衍射(XRD)、拉曼光谱(Raman)测试参数为依据,相对于岩浆热变质作用,深成叠加热液变质背景石墨烯样品的L_(c)、d_(002)以及峰位差G-D、I_(D)/I_(G)的变化随Ro,max的变化较大;而相对于深成叠加热液变质作用,岩浆热变质背景石墨烯样品的L_(a)和L_(a)/L_(c)变化随Ro,max的变化较大;说明在深成叠加热液变质作用背景下,煤的变质程度越高,越易得到堆砌性好、定向排列强、缺陷少的石墨烯样品,而在岩浆热变质作用条件下,煤的变质程度越高,越易获得横向尺寸大、“扁圆”空间形态的石墨烯样品。如今所进行的工作在后续还有拓展研究的空间,岩浆以及无岩浆对煤制石墨烯结构的影响有何不同,或者温度和压力是如何影响煤制石墨烯结构,这些问题需进一步研究以推进煤制石墨烯领域的科学发展。

社会关系与空间要素的互动演化研究——以上海市贵州西社区为例

在近百年的城市发展演变中,上海传统里弄空间与内部社群之间的关系逐渐变得错综复杂,其更新改造也常常因此陷入困境。为有效推进里弄社区的精细化更新,挖掘社区空间更新的症结所在,本文以微观城市形态学为研究方法,以上海市贵州西社区为研究对象,通过对其历史形态的研究,阐释里弄空间结构演变及其内部社区变化的互动演化过程,辨析里弄空间物质性要素与社区社会关系的互动演化特征,并基于此进一步探讨以空间公私领域再结构化为路径指引的里弄更新策略,以及微观城市形态学研究于中国社区精细化治理的适用性与局限性。

贵州西部茅口组灰岩岩溶作用的关键元素与化学溶蚀指数研究

为厘定茅口组灰岩岩溶化程度的化学溶蚀指数(chemical dissolution index,CHI),采用岩矿鉴定、电镜扫描和能谱分析试验,运用单因素方差分析和多变量判别分析确定贵州西部茅口组灰岩岩溶作用的关键元素,依据主成分贡献率理论建立化学溶蚀指标。结果表明:强岩溶化、中岩溶化和新鲜灰岩微观平均面岩溶发育率分别为16.658%,7.892%,0.073%;不同岩溶化程度灰岩地球化学成分差异的关键元素及影响程度大小依次为Ca,Si,Fe,Al,Mg,O,C;建立的半定量化学溶蚀指数为CHI=-16.937×ln w(Ca)-5.675×ln w(Mg)-4.925×ln w(Si)+3.025×ln w(Al)+1.240×ln w(Fe)-43.308,该指数基本反映了灰岩岩溶化实际情况,可为贵州西部岩溶区工程建设提供理论与技术支持。