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  1. Article ; Online: Acoustic emission characteristics and damage evolution of basalt by microwave irradiation

    Jinqiang Yang / Chaolin Wang / Yu Zhao / Jing Bi

    Scientific Reports, Vol 13, Iss 1, Pp 1-

    2023  Volume 17

    Abstract: Abstract The microwave-assisted rock breaking technology has been proven to be feasible, and has received considerable attention in the field of civil and mining engineering. A copper foil was used to wrap basalt to simulate rock excavation of practical ... ...

    Abstract Abstract The microwave-assisted rock breaking technology has been proven to be feasible, and has received considerable attention in the field of civil and mining engineering. A copper foil was used to wrap basalt to simulate rock excavation of practical application scenario in this paper. To this end, a multi-mode cavity with an operating frequency of 2.45 GHz was used to conduct microwave irradiation experiments on basalts with different irradiation times and different power. The thermal properties, AE characteristics, and damage evolution process of basalt were studied. The results show that the high heat generated by microwave leads to the development of cracks in the upper part of basalt. The higher the power level, the higher the degree of crack propagation in the sample, the lower the basalt strength, and the more active the AE activity. The fluctuation rule of the b value indicates that the basalt is dominated by small-scale microfractures before failure. High power levels or long irradiation time lead to more microwave-induced cracks participating in the failure process during loading. Compared with unheated basalt, microwave-heating basalt detects the characteristics of the precursor of failure in advance. The AE source location and the nephogram of the maximum principal stress of microwave-treated basalt reflected that the fracture path begins in the upper part of the rock. In addition, the combination of high power level and short irradiation time can achieve the purpose of energy saving.
    Keywords Medicine ; R ; Science ; Q
    Subject code 621
    Language English
    Publishing date 2023-04-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Study on Crack Classification Criterion and Failure Evaluation Index of Red Sandstone Based on Acoustic Emission Parameter Analysis

    Jiashen Li / Shuailong Lian / Yansen Huang / Chaolin Wang

    Sustainability, Vol 14, Iss 5143, p

    2022  Volume 5143

    Abstract: The acoustic emission (AE) characteristics of rock during loading can reflect the law of crack propagation and evolution in the rock. In order to study the fracture mode in the process of rock fracture, the AE characteristics and crack types of red ... ...

    Abstract The acoustic emission (AE) characteristics of rock during loading can reflect the law of crack propagation and evolution in the rock. In order to study the fracture mode in the process of rock fracture, the AE characteristics and crack types of red sandstone during fracture were investigated by conducting Brazilian indirect tensile tests (BITT), direct shear tests (DST), and uniaxial compression tests (UCT). The evolution law of AE event rate, RA and AF values, and the distribution law of RA–AF data of red sandstone samples in three test types were analyzed. Based on the kernel density estimation (KDE) function and the coupling AE parameters (RA–AF values) in DST and BITT, the relatively objective dividing line for classifying tensile and shear cracks was discussed, and the dividing line was applied to the analysis of fracture source evolution and the failure precursor of red sandstone. The results show that the dividing line for classifying tensile and shear cracks of red sandstone is AF = 93RA + 75. Under uniaxial compression loading, the fracture source of red sandstone is primarily shear source in the initial phase of loading and tensile source in the critical failure phase, and the number is far greater than shear source. K = AF/(93RA + 75) can be defined as the AE parameter index, and its coefficient of variation CV (k) can be used as the failure judgment index of red sandstone. When CV (k) < 1, it can be considered that red sandstone enters the instability failure phase.
    Keywords acoustic emission ; sensor ; parameter analysis ; RA and AF ; crack classification criterion ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
    Subject code 669
    Language English
    Publishing date 2022-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Pore structure and fractal analysis of coal subjected to multiple treatments based on nuclear magnetic resonance

    Zairong Yang / Yu Zhao / Chaolin Wang / Jing Bi

    Energy Science & Engineering, Vol 10, Iss 8, Pp 2842-

    2022  Volume 2849

    Abstract: Abstract Microwave heating (MW) and freeze fracturing (FF) have been widely used for enhancing the permeability of coal reservoirs. In this paper, the effects of combined MW–FF treatments on coals are experimentally investigated through nuclear magnetic ... ...

    Abstract Abstract Microwave heating (MW) and freeze fracturing (FF) have been widely used for enhancing the permeability of coal reservoirs. In this paper, the effects of combined MW–FF treatments on coals are experimentally investigated through nuclear magnetic resonance. T2 distributions and fractal dimensions of coals under MW, FF, and the combined MW–FF treatments are compared and analyzed. The results show that the T2 area, porosity, and fractal dimensions of coals increase to varying degrees after MW, FF, and MW–FF treatment. The T2 spectrum peaks increase from 2 to 3 and macrofractures can be observed after the coal was treated with the combined MW–FF treatments. However, these phenomena are not observed under MW or FF treatment. The combined MW–FF treatments can effectively fracture coals with less microwave energy and less liquid nitrogen freezing cycle owing to its intensive thermal shock fracturing. Therefore, the combined MW–FF treatment is favorable for fracturing the coals and hence favorable for the CBM production.
    Keywords fractal dimension ; fracturing ; nuclear magnetic resonance ; porosity ; Technology ; T ; Science ; Q
    Subject code 660
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: A method for simultaneously determining axial permeability and transverse permeability of tight reservoir cores by canister degassing test

    Yu Zhao / Chaolin Wang / Jing Bi

    Energy Science & Engineering, Vol 8, Iss 4, Pp 1220-

    2020  Volume 1230

    Abstract: Abstract Permeability anisotropy of shale and tight gas reservoirs is critical for applications in unconventional gas recovery, but laboratory measurements are still limited. This paper presents an experimental method for determining permeability ... ...

    Abstract Abstract Permeability anisotropy of shale and tight gas reservoirs is critical for applications in unconventional gas recovery, but laboratory measurements are still limited. This paper presents an experimental method for determining permeability anisotropy of shale and tight reservoirs. The method uses gas production data from a canister and an analytical solution of continuity equation in anisotropic core sample. Axial permeability and transverse permeability of the core are estimated by matching experimental data with analytical solution. The proposed method is verified by comparing with true values and calculated values through numerical simulations that cover variations in rock permeability. The method is applied to real data measured in canister degassing tests (CDT) involving two different directional shale core samples. Then, the experimental results are compared with the results from pulse pressure decay (PPD) method. Both the verification from numerically calculated results and the comparison between PPD results and CDT results exhibit the practicality of the proposed method. At last, the effects of permeability anisotropy, porosity, initial gas pressure, rock dimensions, and adsorption on the profiles of gas production are investigated.
    Keywords anisotropy ; canister degassing experiment ; rock permeability ; tight reservoir ; Technology ; T ; Science ; Q
    Subject code 550
    Language English
    Publishing date 2020-04-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Permeability model of fractured rock with consideration of elastic‐plastic deformation

    Yu Zhao / Chaolin Wang / Jing Bi

    Energy Science & Engineering, Vol 8, Iss 2, Pp 441-

    2020  Volume 451

    Abstract: Abstract The evolution of rock permeability has been studied exhaustively, and a broad array of permeability models has been proposed. These models are normally derived under the assumption of elastic deformation when subjected to external stress. Under ... ...

    Abstract Abstract The evolution of rock permeability has been studied exhaustively, and a broad array of permeability models has been proposed. These models are normally derived under the assumption of elastic deformation when subjected to external stress. Under this assumption, these models define fracture permeability as a function of either gas pressure or effective stress. However, experimental observations indicate that rock fracture may experience unrecoverable deformation during the loading process. The goal of this study is to resolve this contradiction. In this study, derivation of fracture permeability correlation for elastoplastic contact of rough surfaces is presented. The proposed method for describing permeability evolution not only considers the topography of fracture surfaces but also and, more importantly, integrates the plastic deformation of rock fracture. Subsequently, the deformation and permeability change of shale sample containing a single rough‐walled fracture is experimentally investigated. The results show that the permeabilities obtained during the loading process are larger than the permeabilities obtained during the unloading process under the same stress conditions and that the fracture deformation cannot be fully recovered during the unloading process. At last, the proposed permeability model is applied to the experimental results and it is shown that the proposed model can predict the laboratory permeability data.
    Keywords elastoplastic ; fracture ; permeability model ; roughness ; shale ; Technology ; T ; Science ; Q
    Subject code 550
    Language English
    Publishing date 2020-02-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Risk assessment of drought in Yun-Gui-Guang of China jointly using the Standardized Precipitation Index and vulnerability curves

    Shaobo Zhong / Chaolin Wang / Yongsheng Yang / Quanyi Huang

    Geomatics, Natural Hazards & Risk, Vol 9, Iss 1, Pp 892-

    2018  Volume 918

    Abstract: Drought is one of the most serious natural disasters in the world and causes great economic losses in China every year, especially in its southwest region. Yet, few studies have reported the quantitative comprehensive risk of drought in the Yunnan, ... ...

    Abstract Drought is one of the most serious natural disasters in the world and causes great economic losses in China every year, especially in its southwest region. Yet, few studies have reported the quantitative comprehensive risk of drought in the Yunnan, Guizhou, and Guangxi provinces of China. Taking these three provinces as the study area, we obtained annual precipitation, disaster loss, and agricultural planting data during 1964–2013. Following an optimal estimation of annual precipitation by the Bayesian maximum entropy method, we mapped the annual Standardized Precipitation Index. Based on the theory of information diffusion and exceeding probability, the hazard of drought was evaluated. We also fit the vulnerability curves using the drought loss data. As a basis, we constructed a multiplicative formula to calculate the comprehensive risk of drought, which integrates the hazard and the vulnerability and produces drought loss rate (DLR) maps. We found that the DLR caused by mild drought was about 3%, moderate drought 10%, severe drought 25%, and extreme drought 50%. We also created a risk zoning map to provide practical information, such as a scientific basis for optimization of regional allocation of resources for drought preparedness and response.
    Keywords Drought ; risk assessment ; Standardized Precipitation Index ; information diffusion ; vulnerability curve ; Environmental technology. Sanitary engineering ; TD1-1066 ; Environmental sciences ; GE1-350 ; Risk in industry. Risk management ; HD61
    Subject code 910
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Taylor & Francis Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Mapping Comparison and Meteorological Correlation Analysis of the Air Quality Index in Mid-Eastern China

    Zhichen Yu / Shaobo Zhong / Chaolin Wang / Yongsheng Yang / Guannan Yao / Quanyi Huang

    ISPRS International Journal of Geo-Information, Vol 6, Iss 2, p

    2017  Volume 52

    Abstract: With the continuous progress of human production and life, air quality has become the focus of attention. In this paper, Beijing, Tianjin, Hebei, Shanxi, Shandong and Henan provinces were taken as the study area, where there are 58 air quality monitoring ...

    Abstract With the continuous progress of human production and life, air quality has become the focus of attention. In this paper, Beijing, Tianjin, Hebei, Shanxi, Shandong and Henan provinces were taken as the study area, where there are 58 air quality monitoring stations from which daily and monthly data are obtained. Firstly, the temporal characteristics of the air quality index (AQI) are explored. Then, the spatial distribution of the AQI is mapped by the inverse distance weighted (IDW) method, the ordinary kriging (OK) method and the Bayesian maximum entropy (BME) method. Additionally, cross-validation is utilized to evaluate the mapping results of these methods with two indexes: mean absolute error and root mean square interpolation error. Furthermore, the correlation analysis of meteorological factors, including precipitation anomaly percentage, precipitation, mean wind speed, average temperature, average water vapor pressure and average relative humidity, potentially affecting the AQI was carried out on both daily and monthly scales. In the study area and period, AQI shows a clear periodicity, although overall, it has a downward trend. The peak of AQI appeared in November, December and January. BME interpolation has a higher accuracy than OK. IDW has the maximum error. Overall, the AQI of winter (November), spring (February) is much worse than summer (May) and autumn (August). Additionally, the air quality has improved during the study period. The most polluted areas of air quality are concentrated in Beijing, the southern part of Tianjin, the central-southern part of Hebei, the central-northern part of Henan and the western part of Shandong. The average wind speed and average relative humidity have real correlation with AQI. The effect of meteorological factors such as wind, precipitation and humidity on AQI is putative to have temporal lag to different extents. AQI of cities with poor air quality will fluctuate greater than that of others when weather changes and has higher correlation with meteorological ...
    Keywords air quality index ; correlation analysis ; inverse distance weighting ; kriging method ; Bayesian maximum entropy ; Geography (General) ; G1-922
    Subject code 333
    Language English
    Publishing date 2017-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article: Analysis of TCRβ and TCRγ genes in Chinese alligator provides insights into the evolution of TCR genes in jawed vertebrates

    Wang, Xifeng / Chaolin Wang / Cuncun Ke / Di Yu / Haitang Han / Jianhui Bai / Kongpan Li / Liming Ren / Peng Wang / Renping Wang / Xin Zhou / Yaofeng Zhao / Yonghe Ma

    Developmental and comparative immunology. 2018 Aug., v. 85

    2018  

    Abstract: All jawed vertebrates have four T cell receptor (TCR) chains that are expressed by thymus-derived lymphocytes and play a major role in animal immune defence. However, few studies have investigated the TCR chains of crocodilians compared with those of ... ...

    Abstract All jawed vertebrates have four T cell receptor (TCR) chains that are expressed by thymus-derived lymphocytes and play a major role in animal immune defence. However, few studies have investigated the TCR chains of crocodilians compared with those of birds and mammals, despite their key evolutionary position linking amphibians, reptiles, birds and mammals. Here, employing an Alligator sinensis genomic bacterial artificial chromosome (BAC) library and available genome data, we characterized the genomic organization, evolution and expression of TRB and TRG loci in Alligator sinensis. According to the sequencing data, the Alligator sinensis TRB locus spans approximately 500 Kb of genomic DNA containing two D-J-C clusters and 43 V gene segments and is organized as Vβ(39)-pJβ1-pCβ1-pDβ1-Dβ2- Jβ2(12)-Cβ2-Vβ(4), whereas the TRG locus spans 115 Kb of DNA genomic sequence consisting of 18 V gene segments, nine J gene segments and one C gene segment and is organized in a classical translocon pattern as Vγ(18)–Jγ(9)-Cγ. Moreover, syntenic analysis of TRB and TRG chain loci suggested a high degree of conserved synteny in the genomic regions across mammals, birds and Alligator sinensis. By analysing the cloned TRB/TRG cDNA, we identified the usage pattern of V families in the expressed TRB and TRG. An analysis of the junctions of the recombined VJ revealed the presence of N and P nucleotides in both expressed TRB and TRG sequences. Phylogenetic analysis revealed that TRB and TRG loci possess distinct evolutionary patterns. Most Alligator sinensis V subgroups have closely related orthologues in chicken and duck, and a small number of Alligator sinensis V subgroups have orthologues in mammals, which supports the hypothesis that crocodiles are the closest relatives of birds and mammals. Collectively, these data provide insights into TCR gene evolution in vertebrates and improve our understanding of the Alligator sinensis immune system.
    Keywords Alligator sinensis ; amphibians ; bacterial artificial chromosomes ; chickens ; complementary DNA ; crocodiles ; ducks ; genes ; genomics ; loci ; mammals ; nucleotide sequences ; nucleotides ; phylogeny ; T-lymphocytes
    Language English
    Dates of publication 2018-08
    Size p. 31-43.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 752411-0
    ISSN 1879-0089 ; 0145-305X
    ISSN (online) 1879-0089
    ISSN 0145-305X
    DOI 10.1016/j.dci.2018.01.009
    Database NAL-Catalogue (AGRICOLA)

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