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碳酸盐黏土型锂资源的发现及意义
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作者 温汉捷 罗重光 +6 位作者 杜胜江 于文修 顾汉念 凌坤跃 崔燚 李阳 杨季华 《科学通报》 EI CAS CSCD 北大核心 2020年第1期53-59,共7页
黏土型锂资源具有矿床规模大、分布稳定、开发利用成本低的特点,成为近年来全球寻找新类型锂资源的一个重要方向.已报道的黏土型锂矿床成因上均与火山物质联系密切,本研究提出了成因机制与碳酸盐岩风化-沉积有关"碳酸盐黏土型锂矿... 黏土型锂资源具有矿床规模大、分布稳定、开发利用成本低的特点,成为近年来全球寻找新类型锂资源的一个重要方向.已报道的黏土型锂矿床成因上均与火山物质联系密切,本研究提出了成因机制与碳酸盐岩风化-沉积有关"碳酸盐黏土型锂矿床"的成矿新类型.主要地质地球化学特征可归纳为:(1)成矿物质来自基底的不纯碳酸盐岩;(2)主要以吸附方式存在于蒙脱石相中;(3)沉积环境对锂的富集具有重要的控制作用,还原、低能、滞留、局限的古地理环境有利于Li富集;(4)除Li外,还可能有Ga和REE的富集.根据这一新的成矿模型,通过科研示范性勘查,在滇中地区获得34×10~4t氧化锂资源量,达到超大型规模,验证了"碳酸盐黏土型锂矿床"这一新类型资源的成矿潜力.由于我国具有这一有利成矿条件的地区众多,可以预期,碳酸盐黏土型锂资源将有望成为我国新的重要的锂资源来源. 展开更多
关键词 碳酸盐岩 黏土型 风化作用
风化条件下高水材料强度劣化试验研究 预览
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作者 周贤良 刘长武 +2 位作者 卢永虎 张连卫 冯波 《科学技术与工程》 北大核心 2019年第2期217-222,共6页
近年来高水材料广泛用于煤矿巷旁充填、注浆加固和堵孔阻漏等工程领域,但易风化仍然是高水材料固有缺陷。为探究高水充填材料风化后的物理力学性质及风化机理,通过ETM力学试验系统对不同风化天数的高水材料进行研究。结果表明:高水材料... 近年来高水材料广泛用于煤矿巷旁充填、注浆加固和堵孔阻漏等工程领域,但易风化仍然是高水材料固有缺陷。为探究高水充填材料风化后的物理力学性质及风化机理,通过ETM力学试验系统对不同风化天数的高水材料进行研究。结果表明:高水材料风化主要是由于空气中的二氧化碳与钙矾石晶体发生反应,且随着风化天数的增加,自由水的流失与钙矾石晶体的逐渐解体会降低材料密实度,间接加速二氧化碳与钙矾石的反应,因此高水材料失水速率与劣化度随着风化天数增加而增大,且呈上升趋势;风化后的高水材料由表及里会形成风化层-过渡层-未风化层结构,风化层呈粉末状,受压即会破坏脱落,几乎不具备承载能力,但过渡层和未风化层仍然具备一定的承载能力;未风化的试件受压过程中会有水分溢出,风化后的试件无水分溢出。未风化的试件破坏形式属于劈裂破坏,风化后的试件破坏则都是在端部出现剪切破坏,剪切带周围会出现许多微裂隙。可见高水充填材料耐久性与其所处环境湿度密切相关。 展开更多
关键词 风化 高水材料 物理力学性质 风化机理
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Quantifying the carbon source of pedogenic calcite veins in weathered limestone:implications for the terrestrial carbon cycle
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作者 Lin Zou Lin Dong +5 位作者 Meng Ning Kangjun Huang Yongbo Peng Shujian Qin Honglin Yuan Bing Shen 《中国地球化学学报:英文版》 EI CAS CSCD 2019年第4期481-496,共16页
The continent is the second largest carbon sink on Earth’s surface.With the diversification of vascular land plants in the late Paleozoic,terrestrial organic carbon burial is represented by massive coal formation,whi... The continent is the second largest carbon sink on Earth’s surface.With the diversification of vascular land plants in the late Paleozoic,terrestrial organic carbon burial is represented by massive coal formation,while the development of soil profiles would account for both organic and inorganic carbon burial.As compared with soil organic carbon,inorganic carbon burial,collectively known as the soil carbonate,would have a greater impact on the long-term carbon cycle.Soil carbonate would have multiple carbon sources,including dissolution of host calcareous rocks,dissolved inorganic carbon from freshwater,and oxidation of organic matter,but the host calcareous rock dissolution would not cause atmospheric CO2drawdown.Thus,to evaluate the potential effect of soil carbonate formation on the atmospheric p CO2level,different carbon sources of soil carbonate should be quantitatively differentiated.In this study,we analyzed the carbon and magnesium isotopes of pedogenic calcite veins developed in a heavily weathered outcrop,consisting of limestone of the early Paleogene Guanzhuang Group in North China.Based on the C and Mg isotope data,we developed a numerical model to quantify the carbon source of calcite veins.The modeling results indicate that4–37 wt%of carbon in these calcite veins was derived from atmospheric CO2.The low contribution from atmospheric CO2might be attributed to the host limestone that might have diluted the atmospheric CO2sink.Nevertheless,taking this value into consideration,it is estimated that soil carbonate formation would lower 1 ppm atmospheric CO2within 2000 years,i.e.,soil carbonate alone would sequester all atmospheric CO2within 1 million years.Finally,our study suggests the C–Mg isotope system might be a better tool in quantifying the carbon source of soil carbonate. 展开更多
关键词 Mg isotope CALCITE VEINS Pedogenic CARBONATE SILICATE WEATHERING CARBONATE WEATHERING
Influence of the biological carbon pump effect on the sources and deposition of organic matter in Fuxian Lake,a deep oligotrophic lake in southwest China
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作者 Haibo He Zaihua Liu +5 位作者 Chongying Chen Yu Wei Qian Bao Hailong Sun Yundi Hu Hao Yan 《中国地球化学学报:英文版》 CSCD 2019年第5期613-626,共14页
Biological carbon pumping(BCP)is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matt... Biological carbon pumping(BCP)is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matter(AOC).However,the mechanisms underlying BCP and the amount of generated AOC deposited effectively,are still poorly understood.Therefore,we conducted a systematic study combining modern hydrochemical monitoring and a sediment trap experiment in Fuxian Lake(Yunnan,SW China),the second-deepest plateau,oligotrophic freshwater lake in China.Temperature,pH,EC(electrical conductivity),DO(dissolved O2),[HCO3^-],[Ca^2+],SIc,partial CO2(pCO2)pressure,and carbon isotopic compositions of HCO3^-(δ^13CDIc)in water from Fuxian Lake all displayed distinct seasonal and vertical variations.This was especially apparent in an inverse correlation between pCO2 and DO,indicating that variations of hydrochemistry in the lake water were mainly controlled by the metabolism of the aquatic phototrophs.Furthermore,the lowest C/N ratios and highestδ^13Corg were recorded in the trap sediments.Analyses of the C/N ratio demonstrated that the proportions of AOC ranged from 30%to 100%of all OC,indicating that AOC was an important contributor to sedimentary organic matter(OC).It was calculated that the AOC flux in Fuxian Lake was 20.43 t C km^-2 in 2017.Therefore,AOC produced by carbonate weathering and aquatic photosynthesis could potentially be a significant carbon sink and may have an important contribution to solving the lack of carbon sinks in the global carbon cycle. 展开更多
关键词 Carbonate weathering Hydrochemical variation BIOLOGICAL CARBON PUMP EFFECT Sediment trap AUTOCHTHONOUS organic CARBON CARBON sink
Geochemistry and sediment in the main stream of the Ca River basin,Vietnam:weathering process,solute-discharge relationships,and reservoir impact
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作者 Ho Thi Phuong Kenji Okubo Md.Azhar Uddin 《中国地球化学学报:英文版》 CSCD 2019年第5期627-641,共15页
In this study,we investigated the chemical composition of dissolved solids in the Ca River basin,North-Central Vietnam.Water samples were collected from August 2017 to July 2018 at three hydrological stations located ... In this study,we investigated the chemical composition of dissolved solids in the Ca River basin,North-Central Vietnam.Water samples were collected from August 2017 to July 2018 at three hydrological stations located in the main stream of the Ca River.Carbonate weathering was found as the dominant process controlling the water chemistry in that area.The average concentrations of dissolved solids generally decreased from upstream to downstream,resulting in low concentrations of the major ions in the downstream basin.Variations in the concentrations of major chemical ions and suspended solids at discharge were also investigated.Major chemical weathering products were found to behave chemostatically with increasing discharges upstream.However,dilution behaviors of solutes were shown in both midstream and downstream.Primary evidence shows that water storage in reservoirs impacts a variety of suspended solids and dissolved solids in the Ca River. 展开更多
关键词 CA River Dissolved SOLIDS GEOCHEMISTRY Carbonate WEATHERING Suspended SOLIDS
“电天牛”系列绞吸船挖岩施工工艺 预览
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作者 窦建强 《水运工程》 北大核心 2019年第6期212-214,共3页
伴随疏浚技术的快速发展,采用大型挖泥船直接开挖大体积风化岩已成为主要施工手段。以“电天牛”系列绞吸船为例,通过合理选用绞刀和绞刀齿、降低绞刀齿磨损、软化岩石等一系列措施,可有效提高船舶生产率、降低施工成本。与传统炸礁、... 伴随疏浚技术的快速发展,采用大型挖泥船直接开挖大体积风化岩已成为主要施工手段。以“电天牛”系列绞吸船为例,通过合理选用绞刀和绞刀齿、降低绞刀齿磨损、软化岩石等一系列措施,可有效提高船舶生产率、降低施工成本。与传统炸礁、清礁施工工艺相比,绞吸船开挖风化岩具有施工效率高、成本较低的优点。 展开更多
关键词 大型绞吸船 风化 砂岩 施工技术
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辽河三角洲湿地表层沉积物的风化特征及其对生物作用的指示意义 预览
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作者 李通通 叶思源 +2 位作者 韩宗珠 袁红明 裴理鑫 《地质论评》 CAS CSCD 北大核心 2019年第1期40-51,共12页
通过对辽河三角洲273个上三角洲平原湿地表层沉积物及100个浅海湿地表层沉积物的粒度和常量元素的系统测试,且对其中的128个表层沉积物样进行了球囊霉素蛋白(GRSP)的提取与分析,揭示了研究区GRSP、粒度、常量元素分布和风化特征及其控... 通过对辽河三角洲273个上三角洲平原湿地表层沉积物及100个浅海湿地表层沉积物的粒度和常量元素的系统测试,且对其中的128个表层沉积物样进行了球囊霉素蛋白(GRSP)的提取与分析,揭示了研究区GRSP、粒度、常量元素分布和风化特征及其控制机制,研究表明:上三角洲平原湿地表层沉积物以砂质粉砂和粉砂为主,而浅海湿地表层沉积物由于受潮汐及波浪的淘洗作用影响,颗粒较粗以粉砂质砂和砂质粉砂为主;研究区常量元素以SiO2和Al2O3含量最高,其它元素平均含量均小于5%,且除了CaO外,其它常量元素与沉积物粒度呈显著相关(p<0.01);值得注意的是,本研究发现有植被覆盖的上三角洲平原湿地地区的风化指数(CIA=58.50)显著地高于浅海湿地沉积物的风化指数(CIA=50.17,p<0.05)以及近基岩山区的风化指数(CIA=52,p<0.05),Na/K值与CIA指数分析表明该区从近基岩山区、浅海湿地至有植被覆盖的上三角洲平原湿地依次呈未受化学风化、初等化学风化和中等化学风化过渡特征,且CIA值与GRSP含量呈显著相关(r=0.47,p<0.01),由此揭示了生物作用在地质体风化过程的重要意义。 展开更多
关键词 球囊霉素蛋白 常量元素 化学风化 辽河三角洲
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农用聚丙烯非织造布的耐候性能研究 预览
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作者 王飞 王浩江 +2 位作者 雷祖碧 刘煜 马玫 《合成材料老化与应用》 2019年第6期7-9,共3页
以PP树脂和多种高效的抗老化助剂为原料,开发了一种PP耐候功能母粒用于PP非织造布耐候改性,并通过氙灯人工加速老化试验方法对改性后的PP非织造布的耐候性能进行了研究。结果表明,经耐候改性后的PP非织造布试样具有良好的耐候性能,可满... 以PP树脂和多种高效的抗老化助剂为原料,开发了一种PP耐候功能母粒用于PP非织造布耐候改性,并通过氙灯人工加速老化试验方法对改性后的PP非织造布的耐候性能进行了研究。结果表明,经耐候改性后的PP非织造布试样具有良好的耐候性能,可满足农业领域的户外使用要求。 展开更多
关键词 聚丙烯 非织造布 耐候 抗老化 母粒
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Author Index for Journal of Mountain Science Volume 16,2019,pp 1-2930
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《山地科学学报:英文版》 SCIE CSCD 2019年第12期2965-2979,共15页
Abdolreza PARTAB IAN.See Roghayeh KASHANI,1023-1034,Abhirup DIKSHIT.Probabilistic rainfall thresholds in Chibo,India:estimation and validation using monitoring system,870-883,Abigail SISNEROS-KIDD.See David PETTEBONE,... Abdolreza PARTAB IAN.See Roghayeh KASHANI,1023-1034,Abhirup DIKSHIT.Probabilistic rainfall thresholds in Chibo,India:estimation and validation using monitoring system,870-883,Abigail SISNEROS-KIDD.See David PETTEBONE,2882-2893,Adam EMMER.Glacier retreat,rock weathering and the growth of lichens in the Chump Valley,Peruvian Tropical Andes,1485-1499,Adeela BATOOL.See Arshad ASHRAF,1150-1159. 展开更多
关键词 ROCK WEATHERING INDIA
风化层国内外研究进展综述 预览
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作者 吴富强 江振寅 《中国煤炭地质》 2019年第A01期5-11,共7页
通过南方风化层试点填图和红土离子吸附型稀土矿研究,广泛收集国内外风化层成果资料的基础上,采用系统论的思维,借鉴含油气系统的观点,首先对动态的风化作用事件、主要影响因素及其产物的研究成果进行分析;重点论述了风化层形成环境、... 通过南方风化层试点填图和红土离子吸附型稀土矿研究,广泛收集国内外风化层成果资料的基础上,采用系统论的思维,借鉴含油气系统的观点,首先对动态的风化作用事件、主要影响因素及其产物的研究成果进行分析;重点论述了风化层形成环境、风化层形成时间、风化层形成机理及风化程度定量研究方面的进展;扼要综述了风化层矿床研究现状;最后提出了在风化层形成机理、古环境恢复、风化层形成时间等方面有待深入研究的热点问题;指出了加强华南地区离子吸附型花岗岩风化层稀土矿勘探开发模式研究,以便高效将资源潜力转化为新兴产业经济所需的矿产品;强调风化层调查与研究是综合性课题,是一项探索性和实践性很强的工作,必须更新填图理念,创新特殊地貌区风化层地质调查与研究。 展开更多
关键词 风化作用 风化层年代学 化学风化指标 风化层
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过表达Na,K-ATPase基因增强了黑曲霉对硅灰石的风化能力
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作者 孙晶晶 余诚峰 +1 位作者 付紫玉 连宾 《微生物学报》 CAS CSCD 北大核心 2019年第6期1164-1173,共10页
【目的】探究和证实黑曲霉钠钾ATP酶(NKA)在硅灰石风化过程中的作用。【方法】以野生型黑曲霉(WT)为原始菌株构建黑曲霉Na,K-ATPaseα1基因(NKAα1)高表达菌株oeNKA。通过测定不同时间点(0d、2d、4d、6d)oeNKA和WT生物量、培养液pH值和... 【目的】探究和证实黑曲霉钠钾ATP酶(NKA)在硅灰石风化过程中的作用。【方法】以野生型黑曲霉(WT)为原始菌株构建黑曲霉Na,K-ATPaseα1基因(NKAα1)高表达菌株oeNKA。通过测定不同时间点(0d、2d、4d、6d)oeNKA和WT生物量、培养液pH值和矿物风化释放的Ca2+浓度,并用X-ray diffraction (XRD)对风化后的矿物残渣进行检测,比较oeNKA和WT菌株对硅灰石这种硅酸盐矿物的风化效果。【结果】oeNKA菌株的NKAα1基因相对表达量和酶活分别为WT菌株的103倍和1.76倍。在持续6d的培养过程中,oeNKA与WT的菌丝体生物量变化趋势相同,在培养第2天时WT显著高于oeNKA,随时间差异逐渐缩小并在第6天达到最低;培养液pH值变化趋势相同,分别下降至3.64和3.87;oeNKA风化硅灰石时所释放Ca^2+浓度(1011.36±47.78μg/g)约为WT (248.30±25.21μg/g)的4倍;XRD检测图谱显示菌株oeNKA对硅灰石风化作用更明显。【结论】NKAα1过表达菌株oeNKA对硅灰石的风化能力显著高于WT菌株,且黑曲霉的NKA与硅灰石的风化有密切关联。 展开更多
关键词 黑曲霉 Na K-ATPase 硅灰石 风化
Assessment of alterability of basalt used for riprap by petrographic examination 预览
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作者 Maria Heloisa Barros de Oliveira Frascá 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期208-213,共6页
All engineering projects consist of several steps,and one of the main tasks is to identify and characterize the most important features of rock types that will be excavated,crushed,or mined for any particular usage pu... All engineering projects consist of several steps,and one of the main tasks is to identify and characterize the most important features of rock types that will be excavated,crushed,or mined for any particular usage purpose,from a single residential building to major works of infrastructure.Laboratory investigation on engineering geology is thus conducted in order to determine the most relevant rock properties when designing structures such as mining shafts,tunnels,buildings,or reservoir dams to be built in sites associated with rocks.A wide range of laboratory tests is available,making the correct choice of test methods greatly relevant to determine the key property for the planned use of the rock.This paper is an illustrative case of laboratory testing of basaltic rocks to be used as riprap in a reservoir dam.It shows the important role of the petrographic study carried out to analyze the distribution pattern of smectite clay minerals.Test results are explained for the assessment of rock alterability,an essential aspect for the selection of the most suitable basalt variety for the envisaged conditions of use. 展开更多
关键词 Rock properties Laboratory testing Test methods Petrographic analysis SMECTITE clay MINERALS BASALTIC rocks Accelerated WEATHERING tests Alterability
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Spatiotemporal evolution of carbon sequestration of limestone weathering in China
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作者 Huiwen LI Shijie WANG +2 位作者 Xiaoyong BAI Yue CAO Luhua WU 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第6期974-991,共18页
Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribu... Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribution, and evolution of this sequestration is highly desirable. On the basis of random forest regression and maximal potential dissolution model for carbonate, we estimated the CS of typical carbonate weathering in China from 2000 to 2014, that is, the sequestration of limestone weathering, using long-term ecologic, meteorological, hydrological raster data, and monitored data from 44 watersheds in China and surrounding regions. We extended our analyses by systematically exploring the spatiotemporal pattern and evolution trend of the flux and total sequestration. High levels of ionic activity coefficients of Ca2+ and HCO3- in limestone regions were observed to be mainly distributed in Northern and Northwestern China with a clear gradient from northwest to southeast. With a contrary spatial pattern, the annual average CS flux(CSF) of limestone weathering in China was estimated to be 4.28 t C km-2 yr-1, with high values mainly in the karst zones in Southeastern China. The mean CSF in different latitudes showed that Southern China(south of 28.14°N) was the region with the largest interannual fluctuation of flux and CSF increases as latitude decreases. The mean CSF in subtropical and tropical(TR) regions was the maximum of all major climate types, and for the frigid(F), mid-temperate(MTE), warm temperate(WTE), and temperate(TE) major climates;the CSF in the desert(D)subdivided climate was the minimum of these climates. By contrast, the values in grassland(G) and broad-leaved forest subdivided climate were the maximum. The pixel-based trend analysis indicated that the CSF of limestone weathering in China was slightly increasing in the period 2000–2014 with a rate of 0.036 t C km-2 yr-1. Furthermore, the annual total CS was estimated to be 7.07 Tg carbon per year(Tg C yr-1) with high levels in 2002, 2008, 展开更多
关键词 LIMESTONE Chemical WEATHERING carbon SINK SPATIOTEMPORAL evolution DISSOLUTION Random forest
Influence of frost weathering on the recession of surfaces of technogenic landforms in Yakutia 预览
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作者 Andrey E.Melnikov Nikolay N.Grib 《寒旱区科学:英文版》 CSCD 2019年第4期257-266,共10页
The article assesses the influence of permafrost weathering on the rate of destruction of technogenic land forms,as exhibit ed on as illustrated by the railway embankment of the Amur Yakut mainline in the Sakha Republ... The article assesses the influence of permafrost weathering on the rate of destruction of technogenic land forms,as exhibit ed on as illustrated by the railway embankment of the Amur Yakut mainline in the Sakha Republic(Yakutia).Studies were carried out on a railway section more than 375 km long.The subsidence rate of the embankment slopes and structur al excavations was determined using laboratory methods that simulate various mechanisms of temperature(with a transi tion through 0℃)impact on rocks.For the first time,a quantitative assessment of the influence of cryogenic weathering on the stability of the railway in the region belonging to the northern building climatic zone is given.For the territory un der consideration,embankment rocks were experimentally determined to undergo more than 100 freezing and thawing cy cles during a year.Under the existing climatic conditions,cryogenic weathering actively affects the embankment of the railway to a depth of 30 cm.Most of the embankment deformations detected during field observations are due to defects in the integrity of this particular layer.The size of the disintegrating layer of particular types of rock comprising the rail way embankment has been established as reaching 10 cm per year.In 5 years following the formation of embankments comprising the upper structure of the railroad tracks,the physical and mechanical properties of rocks,which initially had a tensile strength for uniaxial compression in the range of 40 70 MPa,were reduced by more than 50%.According to the authors,the establishment of regional cryohypergenesis features is universal in nature and can be applied to solving a wide range of tasks related to the assessment and prediction of the degree of cryogenic transformation of rocks having different structural properties. 展开更多
关键词 cryogenic WEATHERING EMBANKMENT railway SUBSIDENCE rate Republic of Sakha YAKUTIA
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Industrial trial of strip-casting weathering steel 预览
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作者 WU Jianchun FANG Yuan 《宝钢技术研究:英文版》 CAS 2019年第2期17-23,共7页
Baostrip has chosen a steel-grade weathering steel for industrial trial. By carefully designing the composition and manufacturing process,qualified weathering-steel products have been successfully produced on the Ning... Baostrip has chosen a steel-grade weathering steel for industrial trial. By carefully designing the composition and manufacturing process,qualified weathering-steel products have been successfully produced on the Ningbosteel-Baosteel strip casting industrialization demo project( NBS) production line. The industrialized practice of Baostrip shows the following: The surface microstructure of weathering-steel products is polygonal ferrite +pearlite,and that of the center is acicular ferrite. After single-stand on-line hot rolling at a 26% low pressure rate,the thickness tolerance ratio controlled within ± 25 μm reaches 99. 6%. The surface convexity and the wedge can be controlled to | C40 |< 50 μm and | W40 |< 30 μm,respectively. The mechanical properties of the strip are superior,exhibiting a yield strength range of( 430 ± 50) MPa,a tensile strength range of( 550 ± 50) MPa,and an elongation range of( 27 ± 5)%. The corrosion resistance is equivalent to that of current commercial atmospheric corrosion-resistant steels,with a relative corrosion rate of 43%. When used,the weathering steel produced by the strip-casting process meets the strict quality and usage requirements of container steel sheets. 展开更多
关键词 STRIP CASTING WEATHERING steel mechanical properties FLATNESS surface quality corrosion resistance
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雷州半岛玛珥湖区玄武岩的年代、地球化学特征及其意义
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作者 汪苗 鹿化煜 《第四纪研究》 CAS CSCD 北大核心 2019年第5期1071-1082,共12页
我国南部雷州半岛是亚洲季风影响的核心区,区域内田洋、青桐洋和九斗洋这3个干玛珥湖沉积序列可为揭示低纬地区亚洲季风的轨道尺度变化提供关键证据。查明这些玛珥湖的形成年代、基底玄武岩的地球化学组成及其风化产物特征,为进一步获... 我国南部雷州半岛是亚洲季风影响的核心区,区域内田洋、青桐洋和九斗洋这3个干玛珥湖沉积序列可为揭示低纬地区亚洲季风的轨道尺度变化提供关键证据。查明这些玛珥湖的形成年代、基底玄武岩的地球化学组成及其风化产物特征,为进一步获得沉积序列的年代控制、揭示沉积物替代指标的古气候意义提供了基础。本研究对3个干玛珥湖基底的玄武岩进行了K-Ar测年、地球化学成分和玛珥湖周围风化剖面粘土矿物的测试分析,得出了以下结论:1)田洋玛珥湖湖盆的形成年代为0.73~0.87Ma,首次报道的青桐洋和九斗洋湖盆的形成时代分别为0.82 Ma和0.81~1.08 Ma,它们均属于早更新世晚期到中更新世早期的石峁岭期火山射气喷发形成的。2)田洋、青桐洋和九斗洋玛珥湖基底玄武岩均属于石英拉斑玄武岩。同一时期喷发的石英拉斑玄武岩广泛分布在玛珥湖的周围,这些玄武岩风化的产物以高岭石、三水铝石以及赤铁矿为主,在降水较为充沛的时期,物理或化学风化的产物随地表径流汇入湖盆,是玛珥湖沉积的主要来源。本研究为正在进行的低纬地区更新世轨道尺度季风降水重建提供了基础。 展开更多
关键词 雷州半岛 玛珥湖 玄武岩 K-AR测年 风化作用
首钢Q345qENH耐候桥梁钢开发与生产实践 预览
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作者 王根矶 韩承良 +1 位作者 冯韦 马国金 《冶金信息导刊》 2019年第2期32-34,37共4页
耐候桥梁钢是桥梁钢发展新趋势,为满足其高的耐候性、低屈强比、高韧性、易焊接要求,成分设计采用低碳、低Pcm成分体系,并组合添加了Cr、Ni、Cu、Mo等耐候元素。由于耐候桥梁钢高合金的成分特点,需对加热工艺和水冷工艺进行特殊控制。... 耐候桥梁钢是桥梁钢发展新趋势,为满足其高的耐候性、低屈强比、高韧性、易焊接要求,成分设计采用低碳、低Pcm成分体系,并组合添加了Cr、Ni、Cu、Mo等耐候元素。由于耐候桥梁钢高合金的成分特点,需对加热工艺和水冷工艺进行特殊控制。采用钢坯刷涂料和低温烧钢工艺保证钢坯除鳞效果,采用水冷工艺改善钢板微观组织,得到针状铁素体+粒状贝氏体混合组织。首钢生产的Q345qENH耐候桥梁钢具有高强度、低屈强比、高韧性和易焊接特点。 展开更多
关键词 耐候 加热温度 除鳞 终冷温度 屈强比
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煤矸石风化对其物理力学性能影响的研究
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作者 张清峰 王东权 +2 位作者 于广云 崔景彦 刘文化 《中国矿业大学学报》 EI CAS CSCD 北大核心 2019年第4期768-774,共7页
本文主要进行了不同风化时间的煤矸石路堤填料现场筛分试验、室内标准击实试验和抗剪强度试验.利用FLAC3D软件建立了煤矸石路堤数值分析模型,分析了不同风化时间、最佳含水量、饱水状态不同路堤高度对路堤稳定性的影响.结果表明:未风化... 本文主要进行了不同风化时间的煤矸石路堤填料现场筛分试验、室内标准击实试验和抗剪强度试验.利用FLAC3D软件建立了煤矸石路堤数值分析模型,分析了不同风化时间、最佳含水量、饱水状态不同路堤高度对路堤稳定性的影响.结果表明:未风化煤矸石和经过不同风化时间的煤矸石粒径分布都不均匀,级配良好.煤矸石风化36个月后,细料含量和最大干密度均达到最大.在最佳含水量状态,随着风化时间的增加,煤矸石的黏聚力持续增加,而在饱水状态下,煤矸石的黏聚力持续降低.数值模拟结果表明:在最佳含水量状态,路堤高度相同时,随着风化时间的增加,安全系数逐渐减小.饱水状态的安全系数明显比最佳含水量状态的低. 展开更多
关键词 煤矸石 风化 试验研究 稳定性 数值模拟 安全系数
Clay minerals in the late Quaternary sediment of Tulare Lake, California: Implications for climate change, weathering, and erosion processes 预览
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作者 Junhua Guo Christine Pyles +1 位作者 William Krugh Rob Negrini 《国际泥沙研究:英文版》 SCIE 2019年第5期432-443,共12页
The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mi... The clay mineralogy of Tulare Lake sediment was examined to investigate hydroclimatic and environmental changes in the southern Sierra Nevada Mountains (SNM) since the most recent glacial maximum. Evolution of clay mineral assemblages elucidates significant changes in weathering, erosion, and hydroclimatic condition in the catchment. During the last glacial period (24.4–15.1 cal ka BP), low illite content implies less physical erosion of the granitic batholith rocks and a cold and arid environment in the southern SNM. Abrupt increases of illite content at 21.8–20.8 and 17.6 cal ka BP resulted from the glacier advances to the ablation zone and illite-rich glacier flour was transported down to the lake. The gradual increase of smectite induced by progressive depletion of illite-rich glacier flour from 17.6 cal ka BP toward the end of this period indicates climate was beginning to get warm and wet. From 11.9 to 5.3 cal ka BP, two warm and wet periods (10.7–9.4 and 8.2–5.2 cal ka BP) were characterized by high smectite/illite content ratios and low illite crystallinity values, suggesting intensive rainfall precipitation and more physical erosion in the highland and lowland catchment as well as more smectite formation in the terrace soils. Since the last glacial period, physical erosion, in comparison to the chemical weathering, was the dominant process responding to the hydroclimatic change in the Tulare Lake catchment. Moderate to weak chemical weathering was signified by the mostly low illite chemical weathering index of the core sediments. Such results suggest that vegetation cover in the southern SNM was low and limited. 展开更多
关键词 CLAY MINERALOGY Sierra NEVADA MOUNTAINS Glaciers WEATHERING Tulare LAKE
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砒砂岩风化特性试验 预览 被引量:3
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作者 杨才千 刘强 +2 位作者 瞿冯 赵艳兵 吴智仁 《水利水电科技进展》 CSCD 北大核心 2019年第5期10-15,共6页
采用X射线衍射仪、超景深三维显微镜对不同深度的砒砂岩进行矿物成分检测及微观结构观测,研究了不同深度砒砂岩的风化特性,选取次生矿物总量、孔隙率作为评价指标,对不同深度砒砂岩的风化程度进行判定。试验结果表明:不同深度砒砂岩中... 采用X射线衍射仪、超景深三维显微镜对不同深度的砒砂岩进行矿物成分检测及微观结构观测,研究了不同深度砒砂岩的风化特性,选取次生矿物总量、孔隙率作为评价指标,对不同深度砒砂岩的风化程度进行判定。试验结果表明:不同深度砒砂岩中所含的矿物种类相同,主要为石英、长石、绿泥石、方解石、伊利石、黑云母、高岭石等,但所含的次生矿物总量不同,随着深度的增加,次生矿物总量降低;随着深度的增加,砒砂岩表面粗糙度逐渐减小,微裂隙、孔隙的尺寸及数目逐渐减少,砒砂岩受外界环境影响减小,风化程度逐渐降低。 展开更多
关键词 砒砂岩 风化 矿物成分 微观结构 孔隙率
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