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Optimal mining sequence for coal faces under a bedding slope:insight from landslide prevention

Journal of Mountain Science 2024年第5期21卷 1775-1798页

作者： LI Qingmiao ZHAO Jianjun LI Zhichao DENG Jie zuo jing LAI Qiyi State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

Repetitive mining beneath bedding slopes is identified as a critical factor in geomorphic disturbances, especially landslides and surface subsidence. Prior research has largely concentrated on surface deformation in plains due to multi-seam coal mining and the instability of natural bedding slopes, yet the cumulative impact of different mining sequences on bedding slopes has been less explored. This study combines drone surveys and geological data to construct a comprehensive three-dimensional model of bedding slopes. Utilizing FLAC3D and PFC2D models, derived from laboratory experiments, it simulates stress, deformation, and failure dynamics of slopes under various mining sequences. Incorporating fractal dimension analysis, the research evaluates the stability of slopes in relation to different mining sequences. The findings reveal that mining in an upslope direction minimizes disruption to overlying strata. Initiating extraction from lower segments increases tensile-shear stress in coal pillar overburdens, resulting in greater creep deformation towards the downslope than when starting from upper segments, potentially leading to localized landslides and widespread creep deformation in mined-out areas. The downslope upward mining sequence exhibits the least fractal dimensions, indicating minimal disturbance to both strata and surface. While all five mining scenarios maintain good slope stability under normal conditions, recalibrated stability assessments based on fractal dimensions suggest that downslope upward mining offers the highest stability under rainfall, contrasting with the lower stability and potential instability risks of upslope downward mining. These insights are pivotal for mining operations and geological hazard mitigation in multi-seam coal exploitation on bedding slopes.

关键词： Bedding rock landslides Mining-induced deformation Bedding slope stability Underground mining sequences Fractal-based strength reduction method

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Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia

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World Journal of Clinical Cases 2022年第17期10卷 5586-5594页

作者： Yan-Yan Jiang Zhi-lin Zhong Min zuo Department of Magnetic Resonance Wuhan Asia General HospitalWuhan 430056Hubei ProvinceChina Department of Radiology Wuhan Yaxin General HospitalWuhan 430056Hubei ProvinceChina Department of Radiology Wuhan Hanyang HospitalWuhan University of Science and TechnologyWuhan 430050Hubei ProvinceChina

BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 ***,early diagnosis and evaluation of cerebral infarction is *** To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral *** Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were *** patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own *** apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were *** correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was *** The DKI parameters of focal and control areas in the study subjects were *** ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control *** MK,RK,and AK values in the lesion area were significantly higher than those in the control *** MK/MD value in the infarct lesions was used to determine the matching ***/MD<5 mm was considered matching and MK/MD≥5 mm was considered ***1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly ***1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control *** MK and MD maps showed a lesio

关键词： Magnetic resonance Multi-delay 3D arterial spin labeling Diffusion kurtosis imaging Acute ischemic cerebral infarction Perfusion Nerve function

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Upcycling electroplating sludge into bioengineering-enabled highly stable dual-site Fe-Ni_(2)P@C electrocatalysts for efficient oxygen evolution

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Nano Research 2024年第8期17卷 6984-6992页

作者： Jiawen Liu Zunpeng zuo Feng Gao Kai Yi Jiahui lin Mengye Wang Zhang lin Feng Huang State Key Laboratory of Optoelectronic Materials and Technologies School of MaterialsSun Yat-Sen UniversityGuangzhou 510275China Department of Chemistry City University of Hong KongHong Kong 999077China School of Metallurgy and Environment Central South UniversityChangsha 410083China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

The advancement of bimetallic catalysts holds significant promise for the innovation of oxygen evolution reaction(OER)*** from adsorbate evolution mechanism(AEM)and lattice oxygen oxidation mechanism(LOM),the incorporation of dual active sites has the potential to foster novel OER pathways,such as the coupled oxygen evolution mechanism(COM),which can surpass the limitations of OER and elevate catalytic *** this study,uniformly distributed Fe/Ni dual-site Fe-Ni_(2)P@C electrocatalysts are crafted by upcycling metals in electroplating sludge via an eco-friendly and sustainable microbial engineering *** findings indicate that a substantial number of defects emerge at the Ni2P crystal during the OER process,laying the groundwork for lattice oxygen ***,the displacement of Ni/Fe in the crystal lattice intensifies the asymmetry of the electronic structure at the metal active sites,facilitating the deprotonation *** research introduces an innovative paradigm for the synthesis of effective and robust transition metal-based OER catalysts,with implications for sustainable energy generation technologies.

关键词： oxygen evolution reaction dual active sites adsorbate evolution mechanism lattice oxygen mechanism bioengineering

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CHINA’S WAR ON POVERTY“China’s poverty alleviation achievements will be remembered for ages”

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China Report ASEAN 2020年第10期5卷 30-33页

作者： He jing zuo lin 不详

On July 31,2019,Voices from the Frontline:China’s War on Poverty,a documentary about China’s poverty alleviation campaign,debuted on *** production follows the inside story of China’s race to eradicate all poverty by the end of 2020 through five *** host and writer of the documentary,*** Lawrence Kuhn,a renowned China expert and recipient of the China Reform Friendship Medal,visited poor households in Guizhou,Gansu,Shanxi,Sichuan and Hainan provinces and the Xinjiang Uygur Autonomous *** interviewed government officials at the central,provincial,city,county,township,and village levels and recorded considerable first-hand information about poverty alleviation programs.

关键词： remember poverty alleviation

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Verifiable Identity-Based Encryption with Keyword Search for IoT from Lattice

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Computers, Materials & Continua 2021年第8期68卷 2299-2314页

作者： lin Mei Chungen Xu Lei Xu Xiaoling Yu Cong zuo School of Science Nanjing University of Science and TechnologyNanjing210094China College of Data Science Taiyuan University of TechnologyTaiyuan030000China Faculty of Information Technology Monash UniversityClayton3800Australia

Internet of Things(IoT),which provides the solution of connecting things and devices,has increasingly developed as vital tools to realize intelligent ***,source-limited IoT sensors outsource their data to the cloud,which arises the concerns that the transmission of IoT data is happening without appropriate consideration of the profound security challenges *** encryption technology can guarantee the confidentiality of private data,it hinders the usability of *** encryption(SE)has been proposed to achieve secure data sharing and ***,most of existing SE schemes are designed under conventional hardness assumptions and may be vulnerable to the adversary with quantum ***,the untrusted cloud server may perform an unfaithful search *** address these problems,in this paper,we propose the first verifiable identity-based keyword search(VIBKS)scheme from *** particular,a lattice-based delegation algorithm is adopted to help the data user to verify both the correctness and the integrity of the search ***,in order to reduce the communication overhead,we refer to the identity-based *** conduct rigorous proof to demonstrate that the proposed VIBKS scheme is ciphertext indistinguishable secure against the semi-honestbut-curious *** addition,we give the detailed computation and communication complexity of our VIBKS and conduct a series of experiments to validate its efficiency performance.

关键词： Internet of Things verifiable lattice searchable encryption

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Introduction of a New Method for Regulating Laves Phases in Inconel 718 Superalloy during a Laser-Repairing Process

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Engineering 2022年第9期16卷 239-246页

作者： Shang Sui Haosheng Li zuo Li Xuan Zhao Liang Ma jing Chen State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design Ministry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072China

The morphology,size,and distribution of Laves phases have important influences on the mechanical properties of laser-repaired Inconel 718(IN718)*** to the deterioration of the substrate zone,the Laves phase in the laser cladding zone of IN718 superalloy cannot be optimized by a hightemperature solution *** this study,an in situ laser heat-treatment method was proposed to regulate the morphology and size of the Laves phase in the laser cladding zone of IN718 superalloy without impacting the substrate *** the in situ laser heat-treatment process,a laser was used to heat previously deposited layers with optimized manufacturing parameters.A thermocouple and an infrared camera were used to analyze thermal cycles and real-time temperature fields,*** and micro-segregations were observed by optical microscopy,scanning electron microscopy,and electron probe *** was found that the in situ laser heat treatment effectively changed the morphology and size of the Laves phase,which was transformed from a continuous striplike shape to a discrete granular *** effective temperature range and duration were the two main factors influencing the Laves phase during the in situ laser heat-treatment *** effective temperature range was determined by the laser linear energy density,and the peak temperature increased with the increase of the linear energy *** addition,the temperature amplitude could be reduced by simultaneously increasing the laser power and the scanning ***,a flow diagram was developed based on the in situ laser heat-treatment process,and the deposition of a single-walled sample with fine and granular Laves phases was detected.

关键词： Laser repair In situ laser heat treatment Inconel 718 alloy Laves phase

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Hyperbolic Dependence of Moment of Inertia onω2 in Bands Involving vi13/2 Orbital and its Application in Configuration Identification

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Chinese Physics Letters 2000年第4期17卷 261-263页

作者： LU jing-Bin LIU Yun-zuo ZHANG Fan Department of Physics Jilin UniversityChangchun 130023 Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000

The so-called hyperbolic dependence of apparent moment of inertia on square of rotational frequency is developed to the bands involving^13/2 quasineutron around A-60 lighter rare-earth *** can be explained as a characteristic of strongly Coriolis mixing in the high-j unique-parity *** applications of such an effectj the previously proposed assignments of band x of^(160)Ho,π1/2^(-)[541]■vi_(13/2)band of^(170)Ta,as well as band B of 168Lu have been reviewed respectively.

关键词： bands Hyperbolic Configuration

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Experimental investigation on flow characteristics in circular tube inserted with rotor-assembled strand using PIV

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Chinese Journal of Chemical Engineering 2019年第1期27卷 1-9页

作者： Lichen He Weimin Yang Changfeng Guan Hua Yan lin Zheng Xiahua zuo College of Mechanical and Electrical Engineering Beijing University of Chemical Technology

Rotor-assembled strand works as a typical tube insert to achieve heat transfer augmentation and scale inhibition in a heat *** this work, the PIV experiment regarding the flow fields in a circular tube inserted with rotor-assembled strand was conducted and the flow characteristics on transverse section and longitudinal section were *** results showed that swirling flow was produced in the tube inserted with rotors and it was particularly strong within the swing diameter of the rotor on the section that contains the rotor;the average turbulence intensity and the radial velocity were improved notably; the velocity vectors on the longitudinal section remained along the direction of a straight line; both the swirling flow and average turbulence intensity were higher for the rotor with three blades than for the rotor with two blades except that the radial velocity was approximate, but they were all reduced by enlarging the lead of the *** of the flow patterns in a circular tube contributes to understanding the heat transfer efficiency and scale inhibition performance of the rotor-assembled strand and provides guidance for its application.

关键词： Particle image velocimetry (PIV) Swirling flow Rotor-assembled strand Circular tube

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The design and fault ride through control of un-interrupted DC-DC Autotransformer

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Science China(Technological Sciences) 2018年第12期61卷 1935-1949页

作者： LI MengBo XIANG Wang zuo WenPing YAO LiangZhong lin WeiXing WEN JinYu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Renewable Energy Department China Electric Power Research Institute TBEA China Xinjiang Sunoasis Co. Ltd

This paper proposed a novel type of DC-DC converter, termed as un-interrupted DC Autotransformer(un-interrupted DC AUTO), which has the capability to ride through DC fault on either side of the converter without blocking any devices. Besides that, the adequately designed converter retains the advantages of DC AUTO technology, namely reduced investment cost and transmission loss. To begin with, the topology and basic attributes of the un-interrupted DC AUTO are illustrated. Then the design goals and the corresponding design procedures are analyzed. Furthermore, an effective control system is proposed to enable the converter steady operation during both normal and faulted conditions. Finally, a 1000 MW ±320 kV/±640 kV test system is built on PSCAD/EMTDC platform to verify the technical feasibility of the proposed converter and the effectiveness of the control strategy.

关键词： DC-DC power conversion DC Autotransformer HVDC converters DC fault control strategy

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Effects of free ammonia on volatile fatty acid accumulation and process performance in the anaerobic digestion of two typical bio-wastes

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Journal of Environmental Sciences 2017年第5期29卷 49-57页

作者： Xuchuan Shi Jia lin Jiane zuo Peng Li Xiaoxia Li Xianglin Guo State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC) School of Environment Tsinghua University Beijing 100084 China Beijing Enterprises Water Group Limited Beijing 100124 China

The effect of free ammonia on volatile fatty acid （VFA） accumulation and process instability was studied using a lab-scale anaerobic digester fed by two typical bio-wastes： fruit and vegetable waste （FVW） and food waste （FW） at 35℃ with an organic loading rate （OLR） of 3.0 kg VS/（m3-day）. The inhibitory effects of free ammonia on methanogenesis were observed due to the low C/N ratio of each substrate （15.6 and 17.2, respectively）. A high concentration of free ammonia inhibited methanogenesis resulting in the accumulation of VFAs and a low methane yield. In the inhibited state, acetate accumulated more quickly than propionate and was the main type of accumulated VFA. The co-accumulation of ammonia and VFAs led to an ＂inhibited steady state＂ and the ammonia was the main inhibitory substance that triggered the process perturbation. By statistical significance test and VFA fluctuation ratio analysis, the free ammonia inhibition threshold was identified as 45 mg/L. Moreover, propionate, iso-butyrate and valerate were determined to be the three most sensitive VFA parameters that were subject to ammonia inhibition.

关键词： Ammonia inhibition VFA accumulation Anaerobic digestion Process indicator Bio-wastes

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