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Tytuł:
Evaluation of differential serum expression of three factors and pulmonary function in patients with silicosis
Autorzy:
Zhu, Ying
Duan, Xia Yu
Cheng, Yun Qi
Yao, Xin Jing
Xu, Hong
Zhang, Kui Sheng
Li, Feng Shi
Yang, Fang
Liu, Liang He
Yuan, Xiang Ju
Powiązania:
https://bibliotekanauki.pl/articles/2086531.pdf
Data publikacji:
2021-08-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
silicosis
pulmonary function
early diagnosis
ROC
PTPN2
factor B
Opis:
ObjectivesSilicosis is a chronic occupational lung disease. As was previously found by the authors, some proteins increased in the lung tissue of activated rats, and protein tyrosine phosphatase non-receptor type 2 (PTPN2), factor B, and vaccinia-related kinase 1 (VRK1) showed highly differential expressions.Material and MethodsIn this study, serum and bronchoalveolar lavage fluid samples were collected from patients with silicosis and healthy people to verify the expression of PTPN2, factor B, and VRK1. The diagnostic value of differentially expressed proteins for silicosis was judged.ResultsThe expression levels of serum PTPN2, VRK1, and factor B in patients with silicosis were significantly higher than those in the control group (p < 0.01). Higher serum PTPN2 and factor B concentrations significantly and negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), maximum vital capacity (VCmax), FEV1, and FVC, suggesting that the high expression of PTPN2 and factor B is associated with decreased pulmonary ventilation function and restrictive ventilatory impairment in patients with silicosis. All area under curve (AUC) measurements generated from single detection events were >0.744, with PTPN2 reaching the highest value (0.858). The AUC, sensitivity, and specificity for the combined diagnosis using factor B and PTPN2 were 0.907, 86.91% and 85.07%, respectively, for factor B and PTPN2. The 3 differentially expressed proteins are potential classes of predictive biomarkers for silicosis.ConclusionsRegarding the economy and test practicality, the best diagnostic combination is factor B and PTPN2 for the analysis of AUC, sensitivity and specificity.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 4; 527-540
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of monovalent and divalent ions in coal gasification brine on the froth entrainment and flotation kinetics of anthracite coal
Autorzy:
Zheng, Kaidi
Bu, Xiangning
Zhou, Shaoqi
Zhang, Jing
Shao, Huaizhi
Sha, Jie
Xie, Guangyuan
Powiązania:
https://bibliotekanauki.pl/articles/1845216.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal gasification brine
salts ions
coal flotation
entrainment
flotation kinetics
DLVO theory
Opis:
Water plays a critical role in various stages of flotation, which brings a lot of pressure to the flotation processing plants resided in dry areas. In this regard, it will be of significance to explore the feasibility of using wastewater resources in mineral flotation. Coal gasification brine (CGB) that contains a high concentration of salts becomes the subject of interest of this study. In this study, a synthetic CGB solution, which was prepared by adding NaCl, MgCl2, and CaCl2 to ultrapure water based on the composition of salts in a real CGB, was used in the flotation of anthracite coal. The comparison results based on the first-order model showed that flotation in the presence of the synthetic CGB solution gave a higher flotation selectivity (SI =7.086) than that of flotation in ultrapure water (SI=3.545). Water recoveries and average bubble sizes in the froth showed that the addition of the three salt ions (Na+, Mg2+, and Ca2+) was conducive to diminishing the entrainment of gangue materials as a result of the reduction of water reporting to the froth. Additionally, the zeta potentials and induction time measurements indicated that only divalent ions of Ca2+ and Mg2+ significantly compressed the double electrical layer and enhanced the attachment between bubbles and coal particles according to DLVO theory, which was further confirmed by the calculation of interaction energy between coal and bubbles. The findings of the present work may promote the use of CGB as a potential water resource in coal flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 960-974
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
COMBINATION OF BERBERINE AND MATRINE AFFECTS APOPTOSIS AND CELLCYCLE IN HUMAN CERVICAL CANCER CELLS
Autorzy:
Zhang, Qijiayu
Sun, Yi
Huang, Yuxi
Sun, Jing
Zhao, Chongbo
Song, Yijun
Wu, Juanhua
Powiązania:
https://bibliotekanauki.pl/articles/895719.pdf
Data publikacji:
2019-12-29
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
apoptosis
cervical cancer
Matrine
berberine
Opis:
Cervical cancer is the fourth leading cause of malignancy-related mortality in women worldwide, and effective advanced-stage therapies are urgently required. Berberine is a quaternary ammonium compound extracted from traditional Chinese medicinal herbs, including Phellodendron spp., with antibacterial and antitumor activities. Matrine, the main active ingredient of Sophora flavescens rhizomes, has not only traditionally described health effects but is also widely used for its anticancer, anti-inflammatory, immunoregulatory, antiviral, and hepatoprotective effects. We investigated the antitumor activities of berberine and matrine against human cervical cancer HeLa and SiHa cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, along with flow cytometry and western blotting analyses, to assess the effect of the compounds on the cellular status and apoptosis- and cell cycle-related proteins. The 24 h half-maximal inhibitory concentrations (IC50) of berberine and matrine were 123.633 ± 4.278 µmol/L and 9.625 ± 0.245 mmol/L against HeLa cells and 105.067 ± 3.745 µmol/L and 8.50 ± 0.23 mmol/L against SiHa cells, respectively. Berberine plus matrine inhibited cancer cell growth and caused cell cycle arrest. We observed an increased stimulation of apoptosis, which was likely mediated by enhanced levels of caspase-3, caspase-9, and B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), as well as decreased Bcl-2 protein expression. Cell cycle arrest in the G1 phase was probably mediated by p21 upregulation and cyclin-dependent kinase (Cdk)-4, Cdk-6, and cyclin D1 suppression. Combination treatment with berberine and matrine effectively inhibited human cervical cancer cell proliferation, most likely by stimulating apoptosis and inducing cell cycle arrest.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 6; 1089-1097
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cultivating Moral Competence of Chinese Undergraduates with KMDD-Sessions
Autorzy:
Zhang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/781239.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Konstanz Method of Dilemma Discussion
Moral Judgment Test
moral and democratic education
Opis:
This study describes the results of interventions with the Konstanz Method of Dilemma Discussion (KMDD) by Georg Lind, with 89 economics undergraduate participants sampled from Guangdong province. The participants’ mean C-score in the Moral Judgment Test increased only a little because of the teacher’s little experience in using KMDD, but otherwise the intervention produced good results: the participants showed great interest in KMDD although this teaching method is very different from the typical Chinese teaching, and they enjoyed the KMDD-sessions and the classroom atmosphere created through it. Students’ feedback will be useful for future application and research on KMDD in China.
Źródło:
Ethics in Progress; 2013, 4, 1; 48-56
2084-9257
Pojawia się w:
Ethics in Progress
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors of Chinese Adolescents’ Moral Judgment Competence – Findings from Hubei Province
Autorzy:
Zhang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/781416.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Moral Judgment Test
C-scores
Chinese adolescents
Opis:
This paper uses MJT designed by German moral psychologist Lind as a measurement tool, selects 1933 teenagers from Wuhan, Xiangfan or Hubei province. The result shows that participants’ C-sore of different age is 16.90. Character of politic lies remarkable difference, and gender, profession, education, etc., doesn’t. But the specific characters of them have something to be concerned. On this basis, the author gives some advices and countermeasures for education departments.
Źródło:
Ethics in Progress; 2012, 3, 1; 83-95
2084-9257
Pojawia się w:
Ethics in Progress
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fate in Thunderstorm by Cao Yu and Hippolytus by Euripides
Autorzy:
Zhang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/915139.pdf
Data publikacji:
2016-06-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Thunderstorm
Hippolytus
fate
tragedy
Opis:
Theatre, as opposed to traditional Chinese drama, was introduced to China through the first Opium War, and the establishment of Chunliushe in Japan is regarded as the birth of the real Chinese play in 1907. Hereafter, many plays were written and performed in China and were accepted as new form plays. Thunderstorm (Leiyu), Cao Yu’s first play, was published in 1934, and became the first masterpiece of modern Chinese theatre, symbolizing its becoming mature. As the playwright admitted, it was influenced by classical Greek Plays, as well as by Henrik Ibsen. This paper reflects upon the theme of fate in Thunderstorm by Cao Yu and Hippolytus by Euripides. Although Cao Yu interpreted that he was influenced by western plays consciously or unconsciously, Thunderstorm has its own Chinese roots. Similarities and differences in the themes of fate are compared by time or history; ethnic or family aspects; and the individual or feminine. The indescribable fate of the protagonists leads to the agony they suffer inside and also effects them outside because of typical social beliefs and family life; meanwhile, it helped to bring fame to the two tragedies.
Źródło:
Studia Azjatystyczne; 2016, 2; 137-151
2449-5433
Pojawia się w:
Studia Azjatystyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of the migration path of the maximum pollutants’ concentration. Case study of the tailing pond, southwest China
Autorzy:
Zhang, Jing
Ma, Yong
Xing, Bing
Zhang, Jian-Min
Ren, Yu-Feng
Liang, Yue
Powiązania:
https://bibliotekanauki.pl/articles/2086910.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
groundwaters
tailing pond
zinc mine
lead mine
ground contaminants
wody gruntowe
staw osadowy
kopalnia cynku
kopalnia ołowiu
zanieczyszczenie gruntu
Opis:
Following China's economic development, lots of tailing deposits have become potential pollution sources, and their leaching would release the trace elements into the natural environment. The leakage rate model and the solute transport models of groundwater are coupled to investigate the effects of the tailing ponds on groundwater. It indicates that the anti-seepage layer is a necessary and important component of the tailing ponds, which could protect the soil or groundwater to be polluted by wastewater. Under three scenarios (scenario A - ideal conditions, scenario B - the worst conditions, and scenario C), the proportions of maximum concentration to source concentration are 1.2, 94.6, and 19.1%, respectively. Under the worst states of anti-seepage layers, the pollution areas after 730, 1800, 3807 and 7300 days were 130 500, 313 200, 523 800, and 729 000 m2, respectively. Compared with Scenario B, the pollution areas of Scenario C after 1800, 3807, and 7300 days were cut by 52.97, 74.55, and 81.73, respectively. Given important anti-seepage layers, the tracking monitor system is necessary and important to discover whether the groundwater was contaminated in time.
Źródło:
Environment Protection Engineering; 2022, 48, 2; 59--72
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of the peak flow reduction of small reservoirs. A case study of the Brown Bridge Pond, Michigan, USA
Autorzy:
Zhang, Jing
Guo, Chen-lin
Xie, Guang-Ming
Xing, Bing
Powiązania:
https://bibliotekanauki.pl/articles/27323980.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Opis:
Due to the high frequency and great damage of flood disasters, it is important to reduce the flood peak when it goes through the reservoir. A hydraulic model which integrates the implicit equation of water balance, water head-discharge carves, and water head-storage carves together, is proposed to simulate the flood peak reduction of a small reservoir. The proposed method was employed to simulate the flood peak reduction in the Brown Bridge Reservoir, Michigan, US. The results show that the proposed method can simulate the flood peak reduction in a small reservoir, and the Brown Bridge Dam can reduce the flood peak when hundred-year floods go through. When all gates or spillways are fully opened, the initial water head of the reservoir significantly influences the capacity of flood peak reduction. When the initial water head of the Brown Bridge Reservoir is 240.18 and 241.40 m, the hundred-year flood peak would be reduced to 23.11 m3/s and 25.85 m3/s, respectively. By optimizing the gates or spillways, the hundred-year flood peak could be reduced. When the initial water head of the reservoir is 241.40 and 240.18 m, the hundred-year flood peak would be reduced to 17.98 and 16.54 m3/s, respectively
Źródło:
Environment Protection Engineering; 2023, 49, 3; 83--94
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Color image encryption scheme based on quaternion discrete multi-fractional random transform and compressive sensing
Autorzy:
Ye, Huo-Sheng
Dai, Jing-Yi
Wen, Shun-Xi
Gong, Li-Hua
Zhang, Wen-Quan
Powiązania:
https://bibliotekanauki.pl/articles/2033985.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
color image encryption
quaternion discrete multi-fractional random transform
compressive sensing
confusion-diffusion strategy
Opis:
A color image compression-encryption algorithm by combining quaternion discrete multi-fractional random transform with compressive sensing is investigated, in which the chaos-based fractional orders greatly improve key sensitivity. The original color image is compressed and encrypted with the assistance of compressive sensing, in which the partial Hadamard matrix adopted as a measurement matrix is constructed by iterating Chebyshev map instead of utilizing the entire Guassian matrix as a key. The sparse images are divided into 12 sub-images and then represented as three quaternion signals, which are modulated by the quaternion discrete multi-fractional random transform. The image blocking and the quaternion representation make the proposed cryptosystem avoid additional data extension existing in many transform-based methods. To further improve the level of security, the plaintext-related key streams generated by the 2D logistic-sine-coupling map are adopted to diffuse and confuse the intermediate results simultaneously. Consequently, the final ciphertext image is attained. Simulation results reveal that the proposed cryptosystem is feasible with high security and has strong robustness against various attacks.
Źródło:
Optica Applicata; 2021, 51, 3; 349-364
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission stability of chirped dark vector quasi-solitons in birefringent fiber system with nonlinear gain
Autorzy:
Xiao, Yan
Zhang, Jing
He, Qi
Powiązania:
https://bibliotekanauki.pl/articles/1835764.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chirped dark vector quasi-soliton
coupled Ginzburg-Landau equation
birefringent fiber
Opis:
In this article, we consider the coupled Ginzburg–Landau equation with variable coefficients including the nonlinear gain and obtain the exact solutions of chirped dark vector quasi-solitons via the ansatz method. Next, the propagation of chirped dark vector quasi-solitons is discussed to verify whether they can be transmitted stably in the birefringent optical fiber system. The numerical simulation shows that this can be achieved. We deeply add the small perturbation to the transmission of dark vector quasi-solitons to make the results above more general. The results further prove the correctness of our solutions.
Źródło:
Optica Applicata; 2021, 51, 1; 51-58
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vps41, a protein involved in lysosomal trafficking, interacts with caspase-8
Autorzy:
Wang, Lu
Pan, Xiao
He, Liangqiang
Zhang, Rong
Chen, Wei
Zhang, Jing
Lu, Min
Hua, Zi-Chun
Powiązania:
https://bibliotekanauki.pl/articles/1039602.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
caspase-8
yeast two-hybrid
Vps41
protein interaction
apoptosis
Opis:
Caspase-8 is a member of the cysteine-aspartic acid protease (caspase) family which plays a central role in apoptosis and development. We screened caspase-8 interacting proteins from mouse T-cell lymphoma and 7.5-day embryo cDNA libraries by yeast two-hybrid system and obtained eleven positive clones, including Vacuolar protein sorting 41 (Vps41), a protein involved in trafficking of proteins from the late Golgi to the vacuole. The interaction of Vps41 with caspase-8 was confirmed by co-immunoprecipitation (co-IP) and co-localization studies in HEK293T cells. Co-IP experiments also showed that Vps41 binds to the p18 subunit of caspase-8 through its WD40 region and RING-finger motif. Furthermore, we found that overexpression of Vps41 promotes Fas-induced apoptosis in A549 human lung adenocarcinoma cells. The cleavage of caspase-3, a caspase-8 downstream effector, was increased when cells were transfected with Vps41-overexpressing plasmid. Together, these results suggest a novel interaction of caspase-8 with Vps41 and provide a potential role of Vps41 beyond lysosomal trafficking.
Źródło:
Acta Biochimica Polonica; 2013, 60, 1; 37-42
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza motywacji, problemów i potrzeb chińskich młodszych nauczycieli języka polskiego jako obcego
Analysis of motivation, problems, and needs of Chinese junior teachers of Polish as a foreign language
Autorzy:
Wang, Jing
Zhang, Huiling
Cao, Yang
Powiązania:
https://bibliotekanauki.pl/articles/31339962.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Gdański. Wydawnictwo Uniwersytetu Gdańskiego
Opis:
With the dynamic development of Chinese Polish Studies since 2018, there has been a growing demand for teachers of Polish as a foreign language who are native Chinese speakers in the labour market of the People’s Republic of China. Nowadays, almost every Polish language centre at a university has its own teaching staff. Many of them are not only quite modest in terms of staff numbers, but also very young in terms of the age and experience of the teachers. Today, both Polish and Chinese language literature still lacks in-depth research on this specific group of glottodidactics. Therefore, the present study aims at getting to know Chinese junior teachers of Polish as a foreign language working at universities, and to gain knowledge about their motivation for their profession, problems and needs at work. From the questionnaire survey of 23 purposively selected respondents, it can be concluded that the greatest motivation of the respondents was related to students and interests in research and/or teaching. The problems they encountered at work were related to insufficient skills, lack of materials and those caused by the work environment. They are most in need of improved teaching methods and techniques, more and better teaching materials and help from masters in this field.
Źródło:
Gdańskie Studia Azji Wschodniej; 2022, 21; 129-145
2353-8724
Pojawia się w:
Gdańskie Studia Azji Wschodniej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Minimum Spectral Radius of Signless Laplacian of Graphs with a Given Clique Number
Autorzy:
Su, Li
Li, Hong-Hai
Zhang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/30148000.pdf
Data publikacji:
2014-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
clique number
kite graph
signless Laplacian
spectral radius
Opis:
In this paper we observe that the minimal signless Laplacian spectral radius is obtained uniquely at the kite graph $PK_{n-\omega,\omega}$ among all connected graphs with $n$ vertices and clique number $\omega$. In addition, we show that the spectral radius $\mu$ of $PK_{m,\omega}$ $(m\geq1)$ satisfies $$\frac{1}{2}(2\omega-1+\sqrt{4\omega^{2}-12\omega+17})\leq\mu\leq 2\omega-1.$$ More precisely, for $m>1$, $\mu$ satisfies the equation \[ \mu-\omega-\frac{\omega-1}{\mu-2\omega+3}=a_m\sqrt{\mu^2-4\mu}+\frac{1}{t_1}, \] where $a_m=\frac{1}{1-t_1^{2m+3}}$ and $t_{1}=\frac{\mu-2+\sqrt{(\mu-2)^{2}-4}}{2}$. At last the spectral radius $\mu(PK_{\infty,\omega})$ of the infinite graph $PK_{\infty,\omega}$ is also discussed.
Źródło:
Discussiones Mathematicae Graph Theory; 2014, 34, 1; 95-102
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of Dendrite Morphology and Micro-Segregation in U-Nb Alloy During Solidification
Autorzy:
Su, Bin
Liu, Jing-Yuan
Zhang, Xiao-Peng
Yan, Xue-Wei
Powiązania:
https://bibliotekanauki.pl/articles/2174585.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
U-Nb alloys
solidification process
dendrite growth
cellular automaton
numerical simulation
Opis:
Due to the importance of uranium and uranium alloys to national defence and nuclear industrial applications, it is necessary to understand dendrite formation in their solidification structures and to control their microstructures. In this study, a modified cellular automaton model was developed to predict 2-D and 3-D equiaxed dendrite growth in U-Nb alloys. The model takes into account solute diffusion, preferential growth orientation, interface curvature, etc., and the solid fraction increment is calculated using the local level rule method. Using this model, 2-D large-scale and 3-D equiaxed dendrite growth with various crystallographic orientations in the U-5.5Nb alloy were simulated, and the Nb micro-segregation behaviour during solidification was analysed. The simulated results showed reasonable agreement with the as-cast microstructure observed experimentally.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1333--1339
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic emission characteristics of deep granite under triaxial cylic loading and unloading
Autorzy:
Pei, Feng
Zhang, Yue-Zheng
Zhao, Ji-Wei
Geng, Jing-Ming
Powiązania:
https://bibliotekanauki.pl/articles/1402362.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
deep granite
acoustic emission
frequency spectrum
precursory feature recognition
Opis:
In order to obtain the damage and AE characteristics of deep granite, TAW-2000 electrohydraulic servo rigid testing equipment and PCI-2 acoustic emission acquisition system were used to clarify the relationship between AE characteristics and stress level under conventional triaxial and cyclic loading and unloading. The results show that: AE characteristic parameters such as counts and energy under different confining pressures have good consistency in reflecting cracks growth process, which correspond to the stress level of rock sample; Before the critical failure, the AE amplitude increases significantly and extremely high peak frequency and extremely low peak frequency began to appear; The phenomenon that peak frequency band number increases significantly can be used as the precursor of rock failure; The change trend of characteristic parameters, amplitude and peak frequency band were related to the stress level of rock, and the loading path has little influence on it, which verified the effectiveness of AE precursory feature recognition; FR value decreases continuously with the increase of cyclic stress level and overall trend is downward, which indicated that AE memory gradually decreases as the stress level increases; From the perspective of damage mechanics, the AE characteristics of rock before failure are explained reasonably by the development of damage rate.
Źródło:
Mining Science; 2020, 27; 209-225
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł

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