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Article ; Online: Study on overburden failure law and surrounding rock deformation control technology of mining through fault

Chunlin Zeng / Yuejin Zhou / Leiming Zhang / Donggui Mao / Kexin Bai

PLoS ONE, Vol 17, Iss

2022 Volume 1

Abstract: In the mining process of working face, the additional stress generated by the fault changes the law of roadway deformation and failure as well as the law of overburden failure. Aiming at the influence of the fault in the mining process of working face, ... ...

Abstract	In the mining process of working face, the additional stress generated by the fault changes the law of roadway deformation and failure as well as the law of overburden failure. Aiming at the influence of the fault in the mining process of working face, this study introduced the geological strength index (GSI) to analyze the stress distribution in the elastic-plastic zone of the surrounding rock of the roadway. And similar experiments under different engineering backgrounds were combined to study the characteristics of overburden movement and stress evolution. Based on the conclusions obtained, the roadway support scheme was designed. This study shows that, compared with ordinary mining, through-the-fault mining causes slippage and dislocation of the fault, the load of the overburden is transferred to both sides of the fault, and the stress near the fault accumulates abnormally. The “three zones” characteristics of the overburden movement disappear, the subsidence pattern is changed from "trapezoid" to "inverted triangle", and the influence distance of the advanced mining stress on the working face is extended from 20m to 30m. The instability range of roadway surrounding rock is exponentially correlated with the rupture degree of the surrounding rock. Through the introduction of GSI, the critical instability range of roadway surrounding rock is deduced to be 2.32m. According to the conclusion, the bolt length and roadway reinforced support length are redesigned. Engineering application shows that the deformation rate of the roadway within 60 days is controlled below 0.1~0.5mm/d, the deformation amount is controlled within 150mm, and the roadway deformation is controlled, which generally meets the requirements of use. The research results provide guidance and reference for similar roadway support.
Keywords	Medicine ; R ; Science ; Q
Subject code	550
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Study on overburden failure law and surrounding rock deformation control technology of mining through fault.

Chunlin Zeng / Yuejin Zhou / Leiming Zhang / Donggui Mao / Kexin Bai

PLoS ONE, Vol 17, Iss 1, p e

2022 Volume 0262243

Abstract	In the mining process of working face, the additional stress generated by the fault changes the law of roadway deformation and failure as well as the law of overburden failure. Aiming at the influence of the fault in the mining process of working face, this study introduced the geological strength index (GSI) to analyze the stress distribution in the elastic-plastic zone of the surrounding rock of the roadway. And similar experiments under different engineering backgrounds were combined to study the characteristics of overburden movement and stress evolution. Based on the conclusions obtained, the roadway support scheme was designed. This study shows that, compared with ordinary mining, through-the-fault mining causes slippage and dislocation of the fault, the load of the overburden is transferred to both sides of the fault, and the stress near the fault accumulates abnormally. The "three zones" characteristics of the overburden movement disappear, the subsidence pattern is changed from "trapezoid" to "inverted triangle", and the influence distance of the advanced mining stress on the working face is extended from 20m to 30m. The instability range of roadway surrounding rock is exponentially correlated with the rupture degree of the surrounding rock. Through the introduction of GSI, the critical instability range of roadway surrounding rock is deduced to be 2.32m. According to the conclusion, the bolt length and roadway reinforced support length are redesigned. Engineering application shows that the deformation rate of the roadway within 60 days is controlled below 0.1~0.5mm/d, the deformation amount is controlled within 150mm, and the roadway deformation is controlled, which generally meets the requirements of use. The research results provide guidance and reference for similar roadway support.
Keywords	Medicine ; R ; Science ; Q
Subject code	550
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Causes of Large Increases in Atmospheric Ammonia in the Last Decade across North America

Xiaohong Yao / Leiming Zhang

ACS Omega, Vol 4, Iss 26, Pp 22133-

2019 Volume 22142

Keywords	Chemistry ; QD1-999
Language	English
Publishing date	2019-12-01T00:00:00Z
Publisher	American Chemical Society
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Pursuer Assignment and Control Strategies in Multi-Agent Pursuit-Evasion Under Uncertainties

Leiming Zhang / Amanda Prorok / Subhrajit Bhattacharya

Frontiers in Robotics and AI, Vol

2021 Volume 8

Abstract: We consider a pursuit-evasion problem with a heterogeneous team of multiple pursuers and multiple evaders. Although both the pursuers and the evaders are aware of each others’ control and assignment strategies, they do not have exact information about ... ...

Abstract	We consider a pursuit-evasion problem with a heterogeneous team of multiple pursuers and multiple evaders. Although both the pursuers and the evaders are aware of each others’ control and assignment strategies, they do not have exact information about the other type of agents’ location or action. Using only noisy on-board sensors the pursuers (or evaders) make probabilistic estimation of positions of the evaders (or pursuers). Each type of agent use Markov localization to update the probability distribution of the other type. A search-based control strategy is developed for the pursuers that intrinsically takes the probability distribution of the evaders into account. Pursuers are assigned using an assignment algorithm that takes redundancy (i.e., an excess in the number of pursuers than the number of evaders) into account, such that the total or maximum estimated time to capture the evaders is minimized. In this respect we assume the pursuers to have clear advantage over the evaders. However, the objective of this work is to use assignment strategies that minimize the capture time. This assignment strategy is based on a modified Hungarian algorithm as well as a novel algorithm for determining assignment of redundant pursuers. The evaders, in order to effectively avoid the pursuers, predict the assignment based on their probabilistic knowledge of the pursuers and use a control strategy to actively move away from those pursues. Our experimental evaluation shows that the redundant assignment algorithm performs better than an alternative nearest-neighbor based assignment algorithm1.
Keywords	multi-robot systems ; pursuit-evasion ; probabilistic robotics ; redundant robots ; assignment ; Mechanical engineering and machinery ; TJ1-1570 ; Electronic computers. Computer science ; QA75.5-76.95
Subject code	629
Language	English
Publishing date	2021-08-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Jieyu Anshen Granule, a Chinese Herbal Formulation, Exerts Effects on Poststroke Depression in Rats

Yuan Du / Jian Ruan / Leiming Zhang / Fenghua Fu

Evidence-Based Complementary and Alternative Medicine, Vol

2020 Volume 2020

Abstract: Jieyu Anshen granule (JY) is a traditional Chinese medicine formula for treating depression and anxiety. The aim of the study was to observe the effects of JY on poststroke depression (PSD) and investigate the underlying mechanism. PSD rat model was ... ...

Abstract	Jieyu Anshen granule (JY) is a traditional Chinese medicine formula for treating depression and anxiety. The aim of the study was to observe the effects of JY on poststroke depression (PSD) and investigate the underlying mechanism. PSD rat model was developed by middle cerebral artery occlusion following chronic unpredictable mild stress in conjunction with isolation rearing. We performed behavioral tests, Western blot, ELISA, and BrdU/NeuN staining. Treatment with JY showed significant antidepressant effect in open-field and sucrose preference tests, as well as significant improvement in beam-walking, cylinder, grip strength, and water maze tests. In addition, treatment with JY could restore the levels of neurotransmitters and decrease the levels of hormone and inflammation cytokines in serum and brain. Treatment with JY also showed significant regulation in the expression of neurotransmitter receptors and NF-κB/IκB-α signaling in the prefrontal cortex and hippocampus. Moreover, the numbers of newborn neurons in the hippocampus were increased by treatment with JY. Our results suggest that JY could ameliorate PSD and improve the neurological and cognitive functions. The antidepressive effect may be associated with the modulation of JY on monoamine system, neuroendocrine, neuroinflammation, and neurogenesis.
Keywords	Other systems of medicine ; RZ201-999
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	Hindawi Limited
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The Use of Herbal Medicines for the Prevention of Glucocorticoid-Induced Osteoporosis

Leiming Zhang / Xiaoli Li / Tianhao Ying / Tian Wang / Fenghua Fu

Frontiers in Endocrinology, Vol

2021 Volume 12

Abstract: Glucocorticoids are drugs that are widely used to suppress inflammation and the activation of the immune system. However, the prolonged use or at high doses of glucocorticoid can result in adverse side effects including osteoporosis, bone loss, and an ... ...

Abstract	Glucocorticoids are drugs that are widely used to suppress inflammation and the activation of the immune system. However, the prolonged use or at high doses of glucocorticoid can result in adverse side effects including osteoporosis, bone loss, and an increased risk of fracture. A number of compounds derived from natural plant sources have been reported to exert anti-inflammatory activity by interacting with the glucocorticoid receptor (GR), likely owing to their chemical similarity to glucocorticoids, or by regulating GR, without a concomitant risk of treatment-related side effects such as osteoporosis. Other herbal compounds can counteract the pathogenic processes underlying glucocorticoid-induced osteoporosis (GIOP) by regulating homeostatic bone metabolic processes. Herein, we systematically searched the PubMed, Embase, and Cochrane library databases to identify articles discussing such compounds published as of May 01, 2021. Compounds reported to exert anti-inflammatory glucocorticoid-like activity without inducing GIOP include escin, ginsenosides, and glycyrrhizic acid, while compounds reported to alleviate GIOP by improving osteoblast function or modulating steroid hormone synthesis include tanshinol and icariin.
Keywords	glucocorticoid-induced osteoporosis ; herb medicine ; escin ; ginsenoside ; glycyrrhizic acid ; icariin ; Diseases of the endocrine glands. Clinical endocrinology ; RC648-665
Subject code	540
Language	English
Publishing date	2021-11-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Identification of decadal trends and associated causes for organic and elemental carbon in PM2.5 at Canadian urban sites

Huanbo Wang / Leiming Zhang / Xiaohong Yao / Irene Cheng / Ewa Dabek-Zlotorzynska

Environment International, Vol 159, Iss , Pp 107031- (2022)

2022

Abstract: Chemically resolved data for fine particulate matter (PM2.5) have been collected across Canada since 2003 through the National Air Pollution Surveillance (NAPS) network. Seven urban sites that have 10–17 years (2003–2019) of PM2.5 organic carbon (OC) and ...

Abstract	Chemically resolved data for fine particulate matter (PM2.5) have been collected across Canada since 2003 through the National Air Pollution Surveillance (NAPS) network. Seven urban sites that have 10–17 years (2003–2019) of PM2.5 organic carbon (OC) and elemental carbon (EC) data were selected for analysis of decadal trends of OC, EC, and OC/EC ratio using the Ensemble Empirical Mode Decomposition method. Results showed that OC and EC decreased by 0.009–0.072 μg m−3 yr−1 and 0.028–0.049 μg m−3 yr−1, or 0.77–3.1 % yr−1 and 3.2–6.7 % yr−1, respectively, depending on the location. The more rapid decrease in EC than OC resulted in an increasing trend in the OC/EC ratio of 0.03–0.19 yr−1 across the sites. Macro-tracer approach was used to estimate source attributions of OC and EC from wood burning, fossil fuel combustion, and secondary aerosol formation. Using this approach, it was identified that the significant decrease in EC during the past decade was predominately caused by reduced on-road emissions. The decreased emissions from wood burning and transportation dominated the decline of OC, but such a decline was largely offset by the enhanced secondary organic aerosol (SOA) formation, resulting in much weaker decline of OC than EC. The enhanced SOA formation was due to the increased biogenic emissions fully offsetting the decreased anthropogenic emissions for volatile organic compounds. These findings highlight the need for quantifying biogenic sources of VOCs and other oxidants that are involved in OC formation at the national scale.
Keywords	Organic carbon ; Elemental carbon ; Long-term trends ; EEMD ; Canada ; Environmental sciences ; GE1-350
Subject code	550
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Comparison of Soil Greenhouse Gas Fluxes during the Spring Freeze–Thaw Period and the Growing Season in a Temperate Broadleaved Korean Pine Forest, Changbai Mountains, China

Chuying Guo / Leiming Zhang / Shenggong Li / Qingkang Li / Guanhua Dai

Forests, Vol 11, Iss 1135, p

2020 Volume 1135

Abstract: Soils in mid-high latitudes are under the great impact of freeze–thaw cycling. However, insufficient research on soil CO 2 , CH 4 , and N 2 O fluxes during the spring freeze–thaw (SFT) period has led to great uncertainties in estimating soil greenhouse ... ...

Abstract	Soils in mid-high latitudes are under the great impact of freeze–thaw cycling. However, insufficient research on soil CO 2 , CH 4 , and N 2 O fluxes during the spring freeze–thaw (SFT) period has led to great uncertainties in estimating soil greenhouse gas (GHG) fluxes. The present study was conducted in a temperate broad-leaved Korean pine mixed forest in Northeastern China, where soils experience an apparent freeze–thaw effect in spring. The temporal variations and impact factors of soil GHG fluxes were measured during the SFT period and growing season (GS) using the static-chamber method. The results show that the soil acted as a source of atmospheric CO 2 and N 2 O and a sink of atmospheric CH 4 during the whole observation period. Soil CO 2 emission and CH 4 uptake were lower during the SFT period than those during the GS, whereas N 2 O emissions were more than six times higher during the SFT period than that during the GS. The responses of soil GHG fluxes to soil temperature ( T s ) and soil moisture during the SFT and GS periods differed. During the SFT period, soil CO 2 and CH 4 fluxes were mainly affected by the volumetric water content (VWC) and T s , respectively, whereas soil N 2 O flux was influenced jointly by T s and VWC. The dominant controlling factor for CO 2 was T s during the GS, whereas CH 4 and N 2 O were mainly regulated by VWC. Soil CO 2 and N 2 O fluxes accounted for 98.0% and 3.1% of the total 100-year global warming potential (GWP 100 ) respectively, with CH 4 flux offsetting 1.0% of the total GWP 100 . The results highlight the importance of environmental variations to soil N 2 O pulse during the SFT period and the difference of soil GHG fluxes between the SFT and GS periods, which contribute to predicting the forest soil GHG fluxes and their global warming potential under global climate change.
Keywords	soil GHG fluxes ; static-chamber method ; freeze–thaw cycle ; soil temperature ; soil volumetric water content ; temperate forest ; Plant ecology ; QK900-989
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Fish, rice, and human hair mercury concentrations and health risks in typical Hg-contaminated areas and fish-rich areas, China

Bo Wang / Min Chen / Li Ding / Yuhang Zhao / Yi Man / Lin Feng / Ping Li / Leiming Zhang / Xinbin Feng

Environment International, Vol 154, Iss , Pp 106561- (2021)

2021

Abstract: Human exposure to methylmercury (MeHg) from consuming contaminated fish has been a major concern for decades. Besides, human MeHg exposure through rice consumption has been recently found to be important in some Asian countries. China is the largest ... ...

Abstract	Human exposure to methylmercury (MeHg) from consuming contaminated fish has been a major concern for decades. Besides, human MeHg exposure through rice consumption has been recently found to be important in some Asian countries. China is the largest country on mercury (Hg) production, consumption, and anthropogenic emission. However, the health risks of human Hg exposure are not fully understood. A total of 624 fish, 299 rice, and 994 human hair samples were collected from typical Hg-contaminated areas and major fish-rich areas to assess the health risks from human Hg exposure in China. Fish and rice samples showed relatively low Hg levels, except the rice in the Wanshan Hg mining area (WMMA). Human hair total Hg (THg) and MeHg concentrations were significantly elevated in WMMA, Zhoushan (ZS), Xiamen (XM), Qingdao (QD), and zinc smelting area (ZSA), and 85% of hair samples in WMMA, 62% in ZS, 40% in XM, 26% in QD, and 17% in ZSA had THg concentrations exceeding the limit set by the USEPA (1 μg/g). Rice consumption was the main pathway (>85%) for human MeHg exposure in the studied Hg-contaminated areas. Meanwhile, fish was the primary human MeHg exposure source (>85%) in coastal cities. Therefore, soil remediation in typical Hg-contaminated areas and scientific guidance for fish consumption in coastal provinces are urgently needed to reduce the health risks from human Hg exposure in China.
Keywords	Methylmercury ; Human exposure ; Dose–response ; Hg-contaminated area ; Fish-rich area ; Environmental sciences ; GE1-350
Subject code	333
Language	English
Publishing date	2021-09-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Characteristics, Accumulation, and Potential Health Risks of Antimony in Atmospheric Particulate Matter

Jiali Jiang / Yunjie Wu / Guangyi Sun / Leiming Zhang / Zhonggen Li / Jonas Sommar / Heng Yao / Xinbin Feng

ACS Omega, Vol 6, Iss 14, Pp 9460-

2021 Volume 9470

Keywords	Chemistry ; QD1-999
Language	English
Publishing date	2021-04-01T00:00:00Z
Publisher	American Chemical Society
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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