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Differences of granitic weathering at the northern and southern feet of Dabie Mountains,Central China:Implication for tectonic and climatic environments

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Science China Earth Sciences 2003年第7期46卷 641-651页

作者：续海金马昌前刘凡杨坤光faculty of Earth Sciences China University of geosciences Graduate School China University of Geosciences faculty of Earth Sciences China University of Geosciences Department of Resource Environment and Agricultural Chemistry Huazhong Agricultural University

Two weathering profiles of Yanshanian granites on the southern and northern feet of the Dabie Mountains were investigated. The results showed that, on the southern foot of the Dabie Mountains, the weathering profile of the Sikongshan biotite monzonitic granite was eroded with remarkable loss of alkila, calcium and silicon, and richness of aluminium during hydrolysis process and in acidic mediums. Feldspar and biotite, major rock-forming minerals, were altered to illite→ (vermiculite→ 1.4 nm transition minerals) ar kaolinite→halloysite. However, on the northern foot of the Dabie Mountains, the Hepeng biotite orthogranite weathering profile was stable, without silicon depletion, but with remarkably enriched iron and noncrystalline during oxidizing process and in feebly acidic-neutral mediums. The major rock-forming minerals such as feldspar and biotite in the Hepeng weathering profile were weathered to smectites and halloysite→noncrystalline. The above results reveal that weathering differences of the granites between southern and northern feet of the Dabie Mountains may be related to climatic environments and tectonic movements. The southern foot, in hot and rainy environments, was uplifted by tectonics and was intensively leached. The soils in the southern slope were under acidic conditions. In contrast, the northern foot was slightly leached in hot and droughty environments, and the soils were under feebly acidic-neutral conditions.

关键词： Dabie Mountains, granite, weathering process, mineralogy, geochemistry.

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Study on Estimation Method of Rock Mass Discontinuity Shear Strength Based on Three-Dimensional Laser Scanning and Image Technique

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Journal of Earth Science 2012年第6期23卷 908-913页

作者：唐辉明葛云峰王亮清苑谊黄磊孙淼军 faculty of Engineering China University of Geosciences Center of Geological environment Department of Land and Resource of Hubei Province

The estimation of shear strength of rock mass discontinuity is always a focal, but difficult, problem in the field of geotechnical engineering. Considering the disadvantages and limitation of exist- ing estimation methods, a new approach based on the shadow area percentage （SAP） that can be used to quantify surface roughness is proposed in this article. Firstly, by the help of laser scanning technique, the three-dimensional model of the surface of rock discontinuity was established. Secondly, a light source was simulated, and there would be some shadows produced on the model surface. Thirdly, to obtain the value of SAP of each specimen, the shadow detection technique was introduced for use. Fourthly, compared with the result from direct shear testing and based on statistics, an empirical for- mula was found among SAP, normal stress, and shear strength. Data of Yujian （~ River were used as an example, and the following conclusions have been made. （1） In the case of equal normal stress, the peak shear stress is positively proportional to the SAP. （2） The formula for estimating was derived, and the predictions of peak-shear strength made with this equation well agreed with the experimental re- suits obtained in laboratory tests.

关键词： rock mechanics rock mass discontinuity shear strength estimation method three-dimensional laser scanning technique image recognition technique.

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Long-term Activity of Earthquake-induced Landslides: A Case Study from Qionghai Lake basin, Southwest of China

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Journal of Mountain Science 2014年第3期11卷 607-624页

作者： WEI Xue-li CHEN Ning-sheng CHENG Qian-gong HE Na DENG Ming-feng TANOLI Javed Iqbal faculty of geosciences and environmental Engineering Southwest Jiaotong Universit Institute of Mountain Hazards and environment Chinese Academy of Sciences

Earthquake-triggered landslides are a major geological hazard in the eastern Tibetan Plateau, and have prolonged impact on earth surface processes and fluvial system. To determine how long co-seismic landslides affect basins, a massive number of landslides existing in Qionghai Lake Basin were investigated for landslide distribution characteristics and geomorphological evidences, with further comparison and analysis using historic seismic analog method. The landslides found in Qionghai Lake Basin showed clear features of seismic triggering with strongly controlled by Zemuhe fault. These landslides are still active at present. Some new slides generally occur in ancient slope failure zones causing serious secondary hazards in recent years. In this study we strengthen the idea that the landslides triggered by the 185o Xichang earthquake （Ms7.5） have long term activity and prolonged impact on the mountain disasters with a period of more than 16o years. Our results support growing evidence that coseismic landslides have a prolonged effect on secondary disasters in a basin, and invite more careful consideration of the relationship between current basin condition and landslide history for a longer period.

关键词： Qionghai Lake Earthquake Landslide Debris flow Sediment yield

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Characteristics of Landslides Induced by the Great Wenchuan Earthquake

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Journal of Earth Science 2010年第1期21卷 104-113页

作者：唐辉明贾洪彪胡新丽李德威熊承仁 faculty of Engineering China University of Geosciences faculty of Earth Sciences China University of Geosciences

The great Wenchuan （汶川） earthquake induced a large quantity of landslides. They are widely distributed and caused tremendous damages. The sliding mechanism and characteristics of these earthquake-induced landslides are different from those of conventional gravity landslides. Their occurrences are apparently controlled by the powerful earthquake, and they are characterized by high potential energy sliding and ejection sliding. In this article, the earthquake-induced landslides are classified, the characteristics of the sliding and destruction of these landslides are described, and the rela- tionship between the earthquake and the landslides is analyzed. The Donghekou （东河口） landslide is used as an example to characterize fast-moving long-distance earthquake-induced ejection slippage and landslide. This research suggests that many phenomena and issues related to earthquake-induced land- slide are beyond current recognition and knowledge, and new methodologies should be adopted to consider the effect of the earthquake as the paramount factor in the development of landslides. Furthermore, the study of fast-moving long-distance earthquake-induced landslides can also shed light on the formation of old and ancient landslides.

关键词： Wenchuan earthquake giant landslide ejection landslide high potential energy land- slide.

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Soil-Air Partitioning of Polychlorinated Biphenyls and Total Dichloro-Diphenyl-Trichloroethanes

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Journal of Earth Science 2014年第4期25卷 741-748页

作者： Yaping Zhang Erping Bi Honghan Chen School of Water Resources and environment China University of Geosciences (Beijing) Beijing Key Laboratory of Water Resources and environment Engineering China University of Geosciences (Beijing)

Soil-air partitioning is an important diffusive process that affects the environmental fate of organic compounds and human health. In this review, factors affecting the soil-air partitioning of polychlorinated biphenyls （PCBs） and total dichloro-diphenyl-trichloroethanes （p,p＇- and o,p＇- isomers of DDT, DDD, and DDE） are discussed. Hydrophobicity is an important factor that influences soil-air partition coefficients （KsA）, and its effect can be explained through enthalpy of phase change for soil-air partitioning transfer （AHsA）. For more hydrophobic compounds, a sharp increase in the KSA of PCBs and organochlorines can be seen in the early aging period. During the aging period, the temperature has a significant effect on the more hydrophobic organic compounds. The content and properties of soil or- ganic matter influence the KSA of the target compounds. Generally, KSA decreases with increasing rela- tive humidity in soils. The linear trend between KSA and temperature （T） changes at 0 ~C. Freezing the air or soil in experiments would change the research results. On the basis of factors influencing soil-air partitioning, a multipleparameter （T, organic carbon fraction （foe）, and octanol-air partition coefficient （KoA）） model is put forward to predict the KSA values for PCBs and total DDTs.

关键词： soil-air interface partition sorption polychlorinated biphenyl (PCB) dichloro-diphenyltrichloroethanes (DDT).

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Determination of Sub-Trace Sc, Y and Ln in Carbonate by ICP-MS with Inter-Element Matrix-Matched Technique

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Journal of Rare Earths 2003年第2期21卷 124-128页

作者：胡圣虹胡兆初刘勇胜林守麟高山 faculty of Earth Sciences China University of Geosciences faculty of Material Science and Chemical Engineering China University of Geosciences

A simple method for the determination of Sc, Y and Ln in carbonate at sub μg·g -1 levels by ICP MS with inter elements matrix matched technique was developed. A series of matrix matched standard solution were prepared by adopting the normalized concentration values, which were calculated the statistic average compositions of reference values of REEs in carbonate standard reference materials. The matrix effects of Ca and Mg on REEs were studied in detail and the results show that the matrix effect of Ca and Mg can be ignored when the dilution factors are more than 1000. The combination of 115 In and 103 Rh as internal standard was selected to compensate the drift of analytical signals. The method proposed was applied to the analysis of ultra trace REEs in carbonate references materials GSR 6, GSR 12 and real samples.

关键词： analytical chemistry ICP MS sub trace carbonate rare earths

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environmental Evolution of the South Margin of Qaidam Basin Reconstructed from the Holocene Loess Deposit by n-Alkane and Pollen Records

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Journal of Earth Science 2013年第2期24卷 170-178页

作者：向树元曾方明王国灿喻建新 faculty of Earth Sciences China University of Geosciences Geological Survey of China University of geosciences Laboratory of Salt Lake Geology and environment Qinghai Institute of Salt LakesChinese Academy of Sciences

This study provides the n-alkane and pollen records of the Holocene loess at Balong Town, Dulan County, Qinghai Province, and the environmental changes reconstructed from both records agreed well. Three stages of past climate change were deciphered by variations of the n-alkane and pollen proxies. Before 5 370 a BP, the climate was warm-dry but slightly humid, corresponding to the Mid-Holocene climatic optimum; 5 370-3 830 a BP, the climate changed alternatively between warm-dry slightly humid and warm-dry, indicating the transition from the Mid-Holocene climatic optimum to the Late Holocene cold period; after 3 830 a BP, the climate was mainly warm-dry. The warm cool and extremely dry climate during 3 040-2 600 a BP was recorded by both the n-alkane and pollen proxies, suggesting the environment evolved into desert or salt lake, in accordance with the cold and highly frequent natural disaster period in the Western Zhou Dynasty （ca. 2 996-2 721 a BP） in China.

关键词： Qaidam Basin Holocene n-alkane loess environmental change.

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Differences in major ions as well as hydrogen and oxygen isotopes of sediment pore water and lake water

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Water Science and Engineering 2018年第2期11卷 147-156页

作者： Zhuo Zhang Hua-ming Guo Zhen Wang State Key Laboratory of Biogeology and environmental Geology China University of Geosciences MOE Key Laboratory of Groundwater Circulation & environment Evolution China University of Geosciences School of Water Resources and environment China University of Geosciences

Isotopic and chemical compositions of pore water(PW) are highly relevant to environmental and forensic study. Five lake water(LW)samples and five sediment samples were collected to investigate the effects of pore sizes of sediments on PW chemistry and stable isotopes and determine mechanisms controlling their variations. Six pore water fractions were extracted from different-sized pores in each sediment sample at six sequential centrifugal speeds for chemical and isotopic analysis. The sediments consisted mainly of quartz, feldspar, and clay minerals. The hydrogen and oxygen isotopic compositions of PW are mainly controlled by the overlying LW, although the lag effect of exchange between overlying LW and PW results in isotopic differences when recharge of LW is quicker than isotopic exchange in PW. Identical isotopic compositions of PW from sediments with different pore sizes indicate that isotopic exchange of water molecules with different pore sizes is a quick process. The ratio of average total dissolved solid(TDS) concentration of PW to TDS concentration of LW shows a strong relationship with adsorption capacity of sediments, demonstrating that remobilization of ions bound to sediments mainly causes a chemical shift from LW to *** of Ca^(2+), Mg^(2+),and Cl^-in PW remain unchanged,while concentrations of Na^+,K^+,and SO_4^(2-) slightly increase with decreasing pore size. Chemical differences of PW from sediments with different pore sizes are governed by ion adsorption properties and surface characteristics of different-si zed particles.

关键词： Pore size Centrifugal extraction Hydrogen and oxygen isotopes Major ions Remobilization

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Evaluation of biostimulation and Tween 80 addition for the bioremediation of long-term DDT-contaminated soil

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Journal of environmental Sciences 2015年第2期27卷 101-109页

作者： Bibiana Betancur-Corredor Nancy J.Pino Santiago Cardona Gustavo A.Peuela GDCON Research Group Faculty of Engineering University Research Headquarters (SIU) University of Antioquia School of geosciences and environment Faculty of Mines National University of Colombia School of Microbiology University of Antioquia

The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis（4-chlorophenyl）ethane（DDT） and its metabolites 1,1-dichloro-2,2-bis（4-chlorophenyl） ethane（DDD） and1,1-dichloro-2,2-bis（4-chlorophenyl） ethylene（DDE） were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and p H and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition（B ＋ S） and 94.3%via biostimulation alone（B）. Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp.,Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy（SEM） allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B ＋ S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5%by natural attenuation after 8 weeks of treatment.

关键词： DDT Soil Bioremediation Biostimulation Surfactant Toxicity

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Lanthanum-doped Cu-Mn composite oxide catalysts for catalytic oxidation of toluene

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Journal of Rare Earths 2019年第6期37卷 602-608页

作者： Jing Pan Wentao Du Yongjun Liu Yan Cheng Shandong Yuan College of Architecture and environment Sichuan University National Engineering Research Center for Flue Gas Desulfurization faculty of geosciences and environmental Engineering Southwest Jiaotong University

CuMn mixed oxides catalysts doped with La were prepared following a co-precipitation method and used for the catalytic oxidation of toluene. Catalysts properties of the catalysts were investigated by X-ray diffraction, N_2 adsorption/desorption,scanning electron microscopy, H_2-temperature-programmed reduction(H_2-TPR), O_2-temperature-programmed desorption(O_2-TPD) and X-ray photoelectron spectroscopy techniques. Characterization data reveal that the phase change and decrease in crystallinity of the La-doped catalysts increase the number of oxygen vacancies. Improvements in reducibility and an increase in the amount of chemisorbed oxygen of the La-doped catalysts were also verified by H_2-TPR and O_2-TPD. The activity of the CuMn mixed oxides catalysts is significantly improved by the addition of a nominal amount of La. The CuMn/La-4 mol% catalyst exhibits the best catalytic activity, with a 90%conversion temperature of 255 ℃,attributed to a high Mn^(3+)ratio, superficial chemisorbed oxygen,and high surface area. This study indicates La to be a promising dopant for Cu-Mn catalysts toward toluene oxidation.

关键词： Manganese Copper Lanthanum Catalytic combustion Toluene Rare earths

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