兰州大学机构库研究单元&专题: 地质科学与矿产资源学院
http:///ir.lzu.edu.cn/:80/handle/262010/113471
2024-03-28T09:20:14Z
2024-03-28T09:20:14Z
Characteristics of the impact pressure of an outburst debris flow: Insights from experimental flume tests
Yang, Yunpeng
Chen, Guan
Meng, Xingmin
Chong, Yan
Shi, Wei
Bian, Shiqiang
Jin, Jiacheng
Yue, Dongxia
http:///ir.lzu.edu.cn/:80/handle/262010/583792
2024-03-15T02:28:15Z
2024-03-15T02:28:14Z
题名: Characteristics of the impact pressure of an outburst debris flow: Insights from experimental flume tests
作者: Yang, Yunpeng; Chen, Guan; Meng, Xingmin; Chong, Yan; Shi, Wei; Bian, Shiqiang; Jin, Jiacheng; Yue, Dongxia
摘要: Debris flows generated by landslide dam failures are highly destructive and can result in rapid, large-scale landscape changes. Understanding the formation and impact dynamics of an outburst debris flow is essential for effective hazard mitigation. In this study, we conducted a series of experiments to investigate the flow dynamics and the impact against an obstacle of outburst debris flows by measuring the flow properties, seismic signals, and impact forces. The results show that the impact of an outburst flow is strongly affected by the evolution of the landslide dam and the internal flow dynamics, which influence its motion and govern its rheology. For an outburst flow with a high sediment concentration caused by intensive dam erosion, the matrix structure can provide cohesive strength for the suspension of coarse particles in the flow. This significantly enhances the stationary mean impact force of the outburst flow. Furthermore, the solid inertial stress, which is a crucial factor representing particle agitation and reflecting flow properties, exhibits a positive power-law correlation with the impact force and a positive linear correlation with seismic energy. This indicates that seismic monitoring can reveal the bulk flow characteristics, internal flow dynamics and their impact characteristics. The seismic energy level increases with the velocity and bulk density of the outburst flow, while its frequency of the seismic data increases with the rate of particle impacts but decreases in the presence of a dampening layer. Our findings provide a scientific perspective for understanding the impact dynamics of an outburst debris flow that could improve the design of measures to mitigate debris-flow hazards. © 2024 Elsevier B.V.
2024-03-15T02:28:14Z
Carbon skeleton dispersed nano-jarosite for efficient Cr (Ⅵ) degradation: A bioinspired MFC cathode catalyst
Wang, Ye
Wang, Qijun
Zhao, Xu
Zhang, Chengbin
Zhou, Yunzhu
Xie, Wenqing
Ren, Guiping
http:///ir.lzu.edu.cn/:80/handle/262010/583786
2024-03-15T02:28:05Z
2024-03-15T02:28:05Z
题名: Carbon skeleton dispersed nano-jarosite for efficient Cr (Ⅵ) degradation: A bioinspired MFC cathode catalyst
作者: Wang, Ye; Wang, Qijun; Zhao, Xu; Zhang, Chengbin; Zhou, Yunzhu; Xie, Wenqing; Ren, Guiping
摘要: Relevant advancements in microbial fuel cells (MFCs) are impeded by the limited oxygen reduction reactions at the cathode. The challenge prompted the development of a jarosite-biochar catalyst using a straightforward biomineralization method. Through X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, we observed a reduction in the agglomeration phenomenon of nano jarosite and a decrease in particle size. The biochar-jarosite MFC demonstrated a significant increase in voltage (682.5 mV) and a maximum power density of 1211 mW/m2. Electrochemical impedance spectroscopy (EIS) showed that the charge transfer resistance of the cathode decreased from 2580 Ω to 111 Ω, demonstrating excellent oxygen reduction reaction (ORR) performance. The jarosite-biochar significantly enhanced the MFC degradation of Cr (VI), exhibiting a 5.2-fold increase, while demonstrating exceptional stability. The X-ray photoelectron spectroscopy (XPS) of Fe and Cr on the surface of jarosite-biochar further substantiates the role of jarosite as an electron mediator between biochar and Cr (VI) in the MFC. Our study presents a cost-effective and efficient biomineralization strategy for the modification of cathode materials in MFCs, offering significant potential for enhancing the catalytic performance of iron-containing carbonaceous composites in Cr (VI) environments. © 2024 Elsevier Ltd
2024-03-15T02:28:05Z
Field experiment on the spatiotemporal evolution of soil moisture in a rainfall-induced loess landslide: Implications for early warning
Chen, Guan
Bian, Shiqiang
Ma, Jianhua
Meng, Xingmin
Shi, Wei
Wu, Jie
Zhang, Yi
Li, Yajun
http:///ir.lzu.edu.cn/:80/handle/262010/583773
2024-03-15T02:27:35Z
2024-03-15T02:27:34Z
题名: Field experiment on the spatiotemporal evolution of soil moisture in a rainfall-induced loess landslide: Implications for early warning
作者: Chen, Guan; Bian, Shiqiang; Ma, Jianhua; Meng, Xingmin; Shi, Wei; Wu, Jie; Zhang, Yi; Li, Yajun
摘要: Rainfall can increase the moisture content of a slope, which changes its mechanical properties and thus acts as an important mechanism to trigger landslides. However, it is unclear how moisture contents vary in space and time during rainfall-induced slope movements, and which soil-wetting patterns precede landslide events. Here, we used point sensors and time-lapse 3D electrical resistivity tomography (tl-3D-ERT) technology to monitor the spatiotemporal evolution of the hydrology and movement within a rainfall-induced loess landslide. We observed that movement of the slope involved a semi-continuous process of initiation, acceleration, and deceleration to stabilization. The slope hydrology evolution suggested that initial saturation, dominant flow, and changes in slope recharge and drainage owing to internal seepage and erosion are important factors that affect moisture changes. The movement accelerated when the average saturation value and spatial variation in moisture distribution within the slope increased; however, the movement decelerated when both parameters did not change significantly with time. The accumulation and dissipation of pore water pressure within the slope owing to uneven humidification may be the underlying cause of changes in landslide movement. Our study demonstrates the potential of tl-3D-ERT for monitoring the spatiotemporal variability of moisture evolution within rainfall-induced landslides to determine landslide deformation trends and develop a landslide early warning system. © 2024 Elsevier B.V.
2024-03-15T02:27:34Z
In situ Fe isotope analysis of Cr-rich iron oxides using pure chromium metal for isobaric interference corrections by femtosecond LA–MC–ICP–MS
Lü, Xinting
He, Detao
Liu, Yongsheng
Li, Ming
Lin, Jie
Chen, Wei
Zhu, Lüyun
Yang, Ao
Feng, Yantong
Liu, Zhenyi
Zeng, Xianli
Hu, Zhaochu
http:///ir.lzu.edu.cn/:80/handle/262010/583749
2024-03-15T02:26:05Z
2024-03-15T02:26:05Z
题名: In situ Fe isotope analysis of Cr-rich iron oxides using pure chromium metal for isobaric interference corrections by femtosecond LA–MC–ICP–MS
作者: Lü, Xinting; He, Detao; Liu, Yongsheng; Li, Ming; Lin, Jie; Chen, Wei; Zhu, Lüyun; Yang, Ao; Feng, Yantong; Liu, Zhenyi; Zeng, Xianli; Hu, Zhaochu
摘要: Iron oxide minerals, such as hematite and magnetite, are commonly found in a wide range of geological environments. Their Fe isotopic composition acts as a potent geochemical tracer, finding applications across various realms of Earth sciences. However, natural iron oxide minerals often have a high Cr content up to percentile levels, necessitating correction of isobaric interference caused by 54Cr+ on 54Fe+ to ensure accurate and precise in situ Fe isotopic compositions. In this study, a pure chromium metal with homogeneous isotopic compositions was examined within the analysis sequence to obtain the fractionation factor of Cr (βCr) for isobaric interference correction. A femtosecond laser ablation system combined with wet plasma conditions was used to decrease the matrix effect. We synthesized a series of magnetite and hematite samples with simple matrix as well as natural magnetite samples with complex matrix to evaluate the feasibility of Cr interference correction. By employing our proposed correction method, the deviation caused by the isobaric interference of 54Cr+ was effectively eliminated. The corrected δ56Fe values for hematite and magnetite samples, even with a Cr/Fe ratio of as high as 1.27, exhibited good agreement with the reference values within the long-term reproducibility uncertainty of 0.10‰. These results indicate the robustness of Cr interference correction in obtaining accurate Fe isotopic compositions of Cr-rich iron oxides. © 2024 Elsevier B.V.
2024-03-15T02:26:05Z
Early Cretaceous (late Barremian–Early Albian) expanding aeolian activity in East Asia: Evidence from the stratigraphic evolution of aeolian deposition in the Baiyin-Jingyuan Basin, northern China
Wang, Fei
Li, Zaijun
Sun, Xiaoyun
Zhao, Jie
Fan, Yuxin
Xia, Dunsheng
Ayyamperumal, Ramamoorthy
Li, Baofeng
http:///ir.lzu.edu.cn/:80/handle/262010/583729
2024-03-15T02:25:25Z
2024-03-15T02:25:24Z
题名: Early Cretaceous (late Barremian–Early Albian) expanding aeolian activity in East Asia: Evidence from the stratigraphic evolution of aeolian deposition in the Baiyin-Jingyuan Basin, northern China
作者: Wang, Fei; Li, Zaijun; Sun, Xiaoyun; Zhao, Jie; Fan, Yuxin; Xia, Dunsheng; Ayyamperumal, Ramamoorthy; Li, Baofeng
摘要: Cretaceous aeolian deposition is important for understanding variations of the tropical–subtropical atmospheric circulation under the greenhouse background. Nevertheless, detailed records revealing the response of aeolian deposition to rising atmospheric CO2 are still lacking. To shed light on their linkage, we examined the Early Cretaceous stratigraphic evolution of the Hekou Group in the Baiyin-Jingyuan Basin, northern China, using multiple methods. The results indicate that the lower Hekou Group is characterized by a transition from submerged alluvial to shallow lacustrine deposition. Overlying these facies is loess-like deposition without bedding, distinguished by grain-size distribution, surface microtextures, and geochemical analysis, which is followed by palustrine deposition. In the palustrine deposition, aeolian sand-dune and sand-sheet deposition can be identified, which gradually developed upward in the Hekou Group, with intercalated wet interdunes, damp interdunes, and pebble-sand sheetflood beds. Finally, aeolian sand dunes and sand sheets dominated the upper Hekou Group. Overall, the upward-changing facies indicated the development of aeolian deposition from an aqueous environment, revealing a long-term paleoclimatic shift from semi-humid, semi-arid to extremely arid, which reflects the expanded aeolian activity in East Asia during the Early Cretaceous. Furthermore, various records were combined to investigate the expanding aeolian activity in East Asia, which indicates a west–east-trending arid belt that was wider than the modern counterpart during the late Barremian–Early Aptian and late Aptian–Early Albian, respectively. These stepwise expansions of aeolian activity were mainly driven by rising atmospheric CO2, which strengthened the subsiding branches of Hadley circulation and the subtropical high, eventually leading to intensified aridification. © 2023 Geological Society of America
2024-03-15T02:25:24Z
Early Cretaceous wildfires and their palaeoenvironmental significance in the Jiuxi Basin, Gansu Province, Northwestern China
Hui, Jianguo
Du, Baoxia
Zhang, Mingzhen
Lin, Shaohua
Jiaoba, Dunzhu
Zhang, Jing
Dai, Shuang
Li, Aijing
Peng, Jing
Liu, Guolong
http:///ir.lzu.edu.cn/:80/handle/262010/583696
2024-03-15T02:24:22Z
2024-03-15T02:24:21Z
题名: Early Cretaceous wildfires and their palaeoenvironmental significance in the Jiuxi Basin, Gansu Province, Northwestern China
作者: Hui, Jianguo; Du, Baoxia; Zhang, Mingzhen; Lin, Shaohua; Jiaoba, Dunzhu; Zhang, Jing; Dai, Shuang; Li, Aijing; Peng, Jing; Liu, Guolong
摘要: The occurrence of palaeowildfires in terrestrial ecosystems coincides with the colonization of plants, rendering it one of the most significant geological events and holding paramount importance for comprehending paleoclimate and paleoenvironmental changes. This study provides strong evidence of persistent palaeowildfire occurrences in the Jiuxi Basin, Northwestern China, during the Aptian to Albian period, considering the abundant, continuous, sedimentary charcoal fossils from the uppermost Chijinbao, Xiagou, and Zhonggou Formations of the Hanxia Section. Micromorphological studies based on the scanning electron microscopy indicate that substantial portion of the charcoal fossils originated from conifers. The fusinite reflectance values of the charcoal fossils range from 1.32% to 4.32%, indicating that the palaeowildfire temperatures may have been 330 °C to 700 °C, and can be divided into three stages, evolving from ground fires to surface fires and crown fires, and finally developing to ground fires. Furthermore, high atmospheric oxygen and seasonally dry climate promoted the frequent palaeowildfire environment in the Jiuxi Basin during the late Early Cretaceous. However, the persistent and repeated wildfires may have effected the palaeoecosystem of the Jiuxi Basin during the late Early Cretaceous, which is evidenced by the decline of coniferous trees and the increase of the early herbaceous angiosperms. © 2023
2024-03-15T02:24:21Z
Algae-Bacteria cooperated microbial ecosystem: A self-circulating semiartificial photosynthetic purifying strategy
Wang, Qijun
Zhang, Chengbin
Zhao, Xu
Wang, Ye
Li, Zitong
Zhou, Yunzhu
Ren, Guiping
http:///ir.lzu.edu.cn/:80/handle/262010/583597
2024-03-15T13:32:35Z
2024-03-15T02:11:23Z
题名: Algae-Bacteria cooperated microbial ecosystem: A self-circulating semiartificial photosynthetic purifying strategy
作者: Wang, Qijun; Zhang, Chengbin; Zhao, Xu; Wang, Ye; Li, Zitong; Zhou, Yunzhu; Ren, Guiping
摘要: The microbial fuel cell (MFC) is a promising bio-electrochemical technology that enables simultaneous electricity generation and effluent purification. Harnessing solar energy to provide sustainable power for MFC operation holds great potential. In this study, a semiartificial photosynthetic self-circulating MFC ecosystem is successfully established through the collaboration of electrogenic microorganisms and photosynthetic algae. The ecosystem can operate continuously without carbon sources and produces a voltage of 150 mV under irradiation. The irradiation doubles the maximum power density of the ecosystem, reaching 8.07 W/m(2) compared to dark conditions. The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) suggest a higher diffusion capacity or faster electron replenishment ability within the ecosystem. Furthermore, the capacity of ecosystem for removing chromium (Cr(VI)) has been investigated comprehensively. Under irradiation, the ecosystem demonstrates a 2.25-fold increase in Cr(VI) removal rate compared to dark conditions. Finally, the results of 16S rRNA amplicon sequencing indicates an increase in the relative abundance of strict and facultative aerobic electroactive bacteria in the ecosystem, including Citrobacter (21 %), Bacillus (15 %) and Enterococcus (6 %). The ecosystem offers a novel, self-sustaining approach to address the challenges of energy recovery and environmental pollution.
2024-03-15T02:11:23Z
In situ S isotopic analysis in apatite using laser ablation-multiple collector-inductively coupled plasma mass spectrometry
Li, Qinglin
Zhang, Wen
Hu, Zhaochu
Feng, Yantong
Hu, Hao
Luo, Tao
Huang, Jing
Zeng, Xianli
http:///ir.lzu.edu.cn/:80/handle/262010/583525
2024-03-15T02:09:26Z
2024-03-15T02:09:25Z
题名: In situ S isotopic analysis in apatite using laser ablation-multiple collector-inductively coupled plasma mass spectrometry
作者: Li, Qinglin; Zhang, Wen; Hu, Zhaochu; Feng, Yantong; Hu, Hao; Luo, Tao; Huang, Jing; Zeng, Xianli
摘要: The S isotope composition (S-34/S-32) in apatite has been considered as a new powerful tool to trace S source reservoirs and to evaluate redox state and dynamic sulfur behavior in magmatic systems. This study presents the first in situ method to analyze S isotope compositions in apatite using laser ablation multiple collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). The sulfur isotope analysis of low-S apatite suffered the problem of high background interference, resulting in a low ratio of signal to noise (S/N). A detailed investigation found that similar to 50% background of S isotopes originated from memory effect in the aerosol particles transformation system and can be removed through careful cleaning or replacement. A linear regression calculation method was proposed instead of the traditional data reduction method to improve the performance of correcting the S background signal. Femtosecond laser ablation system (fs-LA) was used to reduce the thermal effect and suppress the potential fractionation of S isotopes during the laser ablation process, significantly improving the stability of delta S-34(V-CDT) values at different laser ablation parameters. Seven natural apatite samples with a large S concentration range were measured by the presented method. A good agreement of delta S-34(V-CDT) values between fs-LA-MC-ICP-MS and IR-MS was obtained. The reproducibility of delta S-34(V-CDT) obtained from fs-LA-MC-ICP-MS was similar to that in SIMS. These results confirm that the presented method can provide high-quality S isotopic compositions in natural apatites. Four apatite samples (Sly-1, Sly-2, MG, and OL-1) with various concentrations of SO3 (0.21% to 1.26%) show the homogeneous S isotope compositions based on the large amounts of repeated analyses using fs-LA-MC-ICP-MS. They are suggested as the high-quality external reference materials for in situ S isotope analysis for LA-MC-ICP-MS and SIMS.
2024-03-15T02:09:25Z
Stability analysis of a loess landslide considering rainfall patterns and spatial variability of soil
Ma, Jianhua
Yao, Yunqi
Wei, Ziran
Meng, Xingmin
Zhang, Zonglin
Yin, Hailong
Zeng, Runqiang
http:///ir.lzu.edu.cn/:80/handle/262010/583515
2024-03-17T02:13:43Z
2024-03-15T02:09:06Z
题名: Stability analysis of a loess landslide considering rainfall patterns and spatial variability of soil
作者: Ma, Jianhua; Yao, Yunqi; Wei, Ziran; Meng, Xingmin; Zhang, Zonglin; Yin, Hailong; Zeng, Runqiang
摘要: Accurate analysis of the stability of rainfall-induced landslides is an important and urgent task. Under complex geological conditions, traditional stability analysis methods cannot meet stability evaluation requirements. To study the impact of the rainfall pattern on the probability of instability of loess slopes, the intensity-frequencyduration curve and breakdown coefficient methods were introduced to analyse the effects of the rainfall extremum distribution and time scale, and bounded random cascade simulation were used to generate random rainfall patterns (RRPs). The obtained RRPs under several classical rainfall patterns were compared in terms of the safety factor, rainfall threshold (Ia/Ia), and annual failure probability (AFP) of loess slopes. Finally, soil preferential flow and spatial variability combined with the RRPs were introduced to analyse the change in the stability of rainfall-induced loess landslides under different theoretical frameworks. It was revealed that the use of a uniform rainfall pattern produced conservative stability evaluation results. Considering the RRPs, the calculation of Ia/Ia and AFP should include the common characteristics of various rainfall patterns. By comprehensively evaluating slope stability considering soil spatial variability and rainfall pattern variability, this study revealed that neglecting certain factors may result in incorrect slope stability estimates. Incorporating multiple assumptions in failure probability evaluation could provide more comprehensive slope safety assessment.
2024-03-15T02:09:06Z
Experimental field study on the formation process of debris flow dam at channel confluence: Implications for early identification of river blockage
Chen, Guan
Chong, Yan
Meng, Xingmin
Yang, Yunpeng
Yue, Dongxia
Jin, Jiacheng
Bian, Shiqiang
Shi, Wei
Zhang, Yi
http:///ir.lzu.edu.cn/:80/handle/262010/583508
2024-03-15T02:26:42Z
2024-03-15T02:08:51Z
题名: Experimental field study on the formation process of debris flow dam at channel confluence: Implications for early identification of river blockage
作者: Chen, Guan; Chong, Yan; Meng, Xingmin; Yang, Yunpeng; Yue, Dongxia; Jin, Jiacheng; Bian, Shiqiang; Shi, Wei; Zhang, Yi
摘要: River blockage induced by tributary debris flow is a common hazardous chain in mountainous areas, which could pose a serious threat to human lives and infrastructures. Especially, the failures of landslide dams in tributaries will amplify the debris flow's magnitude, which could increase the probability of river blockage. However, the dynamic process and criterion of the river blockage induced by such debris flow have not been well understood. Here, we modeled the entire process of river blockage induced by tributary debris flow through large-scale field experiments. The formation process of the river blockage can be outlined into four stages according to the dynamic characteristics at the junction: erosion and entrainment of the river, expansion of the debris flow deposits, damming of the main river, and the dam overflowing and breaching. The erosion rate of the main river and the momentum of debris flow dominate the first and latter processes of the river blockage respectively, and the shift is accompanied by the increasing momentum of the debris flow. Additionally, the erosion rate of the river and the momentum of the debris flow play differential importance in each type of river blockage. The river's influence is significant for the formation of major blockage and partial blockage if the momentum of tributary debris flow is relatively small. Once the momentum of debris flow is high enough, dynamic characteristics of the tributary are vital for the type of blockage. Then, we established a criterion based on the process of erosion and deposition in the confluence zone. The criterion was verified by 5 river blockage events in the field. It is found that the coupling of the two indicators will improve the accuracy of identification of river blockage compared with existing criteria. In particular, it is possible to better distinguish the type of blockage. This study would advance the understanding of a debris flow dam's formation, and it is meaningful for the early identification of river blockage.
2024-03-15T02:08:51Z