Article
Mechanics
T. H. Ma, X. Zhu, C. A. Tang, W. R. Li
Summary: This study conducts numerical simulations on bi-layered three-dimensional models of different geometric surfaces to explore the formation process of fracture spacing, revealing that curvature has a significant impact on crack density in addition to fractured layer thickness. It also finds differences in fracture patterns on different surface models, with transitions from parallel fractures to regular polygonal fractures observed in slab and cylindrical surface models, while only uniform polygonal fractures emerge in spherical surface models under radial expansion conditions.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Review
Chemistry, Physical
Jinshui Miao, Chuan Wang
Summary: This review summarizes typical photodetection mechanisms in 2D photodetectors, discusses avalanche mechanisms induced by impact ionization and avalanche photodetectors based on conventional silicon and III-V compound semiconductors, and details emerging avalanche photodetectors based on 2D materials along with their potential applications.
Article
Materials Science, Multidisciplinary
Bo Ni, Doug Steinbach, Zhenze Yang, Andrew Lew, Boyu Zhang, Qiyi Fang, Markus J. Buehler, Jun Lou
Summary: This article reviews the recent progress in experimental and theoretical studies of fracture in 2D materials and highlights the challenges and opportunities in this emerging field.
Article
Geochemistry & Geophysics
A. I. Chemenda, J. Lamarche, C. Matonti, L. Bazalgette, P. Richard
Summary: Fracturing significantly affects both the mechanical stability and permeability of rocks. Studies have shown that the relationship between fracture spacing and the thickness of fractured layers is generally nonlinear, especially in thick beds. Modeling has revealed that the number of fractures in a layer reaches saturation under horizontal extension, and the ratio D = T/S shows a close to linear increase with T.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Review
Chemistry, Multidisciplinary
Guan-E Wang, ShaoZhen Luo, Tuo Di, ZhiHua Fu, Gang Xu
Summary: This Minireview provides a comprehensive overview of the latest developments in organic metal chalcogenides (OMCs) and their bulk precursors. It introduces the structure types of OMCs' bulk precursors and explores the synthesis and applications of OMC 2D materials in photoelectricity, catalysis, sensors, and energy transfer. Furthermore, it discusses the challenges and future perspectives for research on OMCs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
Shenmao Lin, Geyang Zhang, Qinglin Lai, Jun Fu, Wenguang Zhu, Hualing Zeng
Summary: With the post Moore era, there is a need for further miniaturization of electronic components, particularly ferroelectric memories, to meet the demand for massive data storage. This has led to the exploration of switchable ferroelectric polarizations at the atomic scale, with recent attention given to van der Waals ferroelectrics due to their stable layered structure at nanometer thickness. This review summarizes recent advancements in layered ferroelectrics, including the fundamentals of two-dimensional ferroelectricity, artificial stacking ferroelectricity, related prototype devices, and unique polarization control in van der Waals ferroelectrics.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Computer Science, Information Systems
Wei Tong, Yuan Liu
Summary: This review article summarizes the recent progress of MoS2-based memristors, including the fabrication process, device structure, device performance, switching mechanism, and synaptic applications. MoS2, widely used as a representative 2D semiconductor, has been intensively studied. The technology shows potential in memory, flexible electronics, neuromorphic computing, and other related fields.
SCIENCE CHINA-INFORMATION SCIENCES
(2023)
Article
Engineering, Mechanical
Yanfei Liu, Shengtao Yu, Ruize Zhang, Xiangyu Ge, Wenzhong Wang
Summary: This study reports the tribological behavior of nanodiamond plate (NDPL) as a nanoadditive for the first time and compares it with nanodiamond particles (NDPA). The results show that NDPL provides better lubrication performance at higher concentrations, and the sliding between NDPLs and the structural transformation from sp3 to sp2 carbon play a crucial role in lubrication and wear resistance.
Article
Chemistry, Physical
Lidong Xing, Kun Han, Qiang Liu, Zhiwei Liu, Jianhua Chu, Lupeng Zhang, Xiumei Ma, Yanping Bao, Ping Li, Wei (Alex) Wang
Summary: The engineered interlayer spacing of two-atom-layered WSe2/C ultrathin crumpled nanosheet assemblies provides a new type of anode with optimal electrochemical performance for nonaqueous potassium-ion batteries. The anode offers advantages such as more active sites, reduced volume expansion, accelerated ion diffusion, and high specific capacity, along with excellent cycling stability.
ENERGY STORAGE MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Lihong Han, Yuanyuan Zou, Qimiao Zeng, Xiaoning Guan, Baonan Jia, Yongpan Gao, Gang Liu, Liyuan Wu
Summary: Based on first-principles calculations, the research reveals an interlayer interaction in two-dimensional PtTe2, leading to a decrease in band gap and a transition from semiconductor to semi-metal as the number of layers increases. This interaction is attributed to the p(z) orbitals of Te atoms in adjacent layers and is represented by a covalent-like Te⋯Te bond.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Review
Physics, Multidisciplinary
Haixin Ma, Yanhui Xing, Boyao Cui, Jun Han, Binghui Wang, Zhongming Zeng
Summary: With the development of Moore's law, devices are becoming smaller and more integrated. The emergence of new two-dimensional non-layered materials enriches the 2D material family and stimulates global interest in basic research and application technologies in the 2D field. Van der Waals heterostructures provide an alternative platform for nanoelectronics and optoelectronic applications. This article outlines recent developments in 2D layered materials/2D non-layered materials hybrid heterostructures, with a focus on synthetic methods and applications. Promising applications in electronics, optoelectronics, and catalysis are highlighted.
Article
Physics, Multidisciplinary
Yuxin Cai, Muhammad Faizan, Huimin Mu, Yilin Zhang, Hongshuai Zou, Hong Jian Zhao, Yuhao Fu, Lijun Zhang
Summary: This study investigates the thermal transport properties of 2D layered materials (2DLMs) and finds that the lattice thermal conductivities of beta-InSe, gamma-InSe, MoS2, and h-BN display diverse anisotropic behaviors. The phonon group velocity is responsible for the anisotropy of thermal transport. The low lattice thermal conductivity of layered InSe mainly comes from low phonon group velocity and atomic masses.
FRONTIERS OF PHYSICS
(2023)
Article
Mechanics
Mehmet Dorduncu, Ibrahim Olmus, Timon Rabczuk
Summary: This study investigated crack initiation and progression in two-dimensional functionally graded plates under dynamic and quasi-static loading conditions using an ordinary state-based PeriDynamic theory. The research found that tailoring the effective material properties in the FG plates in two directions using a rule of mixture can increase plate strength and fracture resistance.
COMPOSITE STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Zhen Yin, Kaichen Xu, Shouzhen Jiang, Dan Luo, Rui Chen, Chunxiang Xu, Ping Shum, Yan Jun Liu
Summary: This article summarizes the recent progress of 2D materials-based SERS technology as a complement to plasmonic SERS substrates. Symmetry of lattice structure, isotropic and anisotropic 2D materials for SERS, and various methods to improve SERS performance are discussed. Sensitivity, limit of detection, and stability of 2D materials-based heterostructures as SERS platforms are also addressed, along with applications in niche areas such as local strain probing, remote/in-situ chemical analysis, and fine structure characterization.
MATERIALS TODAY PHYSICS
(2021)
Article
Chemistry, Physical
G. Maheshwaran, M. Ramesh Prabhu, G. Ravi, K. Sankaranarayanan, S. Sudhahar
Summary: The design and fabrication of an effective piezoelectric self-charging hybrid supercapacitor that can efficiently collect, convert, and store energy in a sustainable and cost-effective way is a cutting edge in advanced research. By fabricating a novel Polyvinyl Alcohol - Potassium hydroxide Barium Titanate (PVA-KOH-BTO) multifunctional piezoelectrolyte based nanogenerator, mechanical energy can be potentially converted into electrical energy. The all-in-one self-charging hybrid supercapacitor (SCHSC) was made using a two-dimensional Bismuthene-hexagonal Boron Nitride nanocomposite (Biene-h-BN NC) as cathode, activated carbon (AC) as anode, and PVA-KOH-BTO as piezoelectrolyte, delivering a specific capacity of 280 C/g at 1 A/g. Moreover, the SCHSC provides a high energy density of 87.5 Wh/kg and a high power density of 11250 W/kg. Notably, the self-charging performance of SCHSC was investigated by externally applying compressive forces, delivering a maximum self-charging potential of 146 mV at a compressive force of 50 N. This research contributes to a new understanding of self-charging performance through the piezoelectrochemical effect and has potential applications in the fabrication of futuristic smart electronic devices.
Article
Chemistry, Physical
Yee-Kwong Leong, Pengfei Liu, Jishan Liu, Peta Clode, Weian Huang
Summary: Composite NaMnt (SWy-2)-kaolin (KGa-2) gels with more than 10 wt% solids and a NaMnt fraction of 20% exhibit an open cellular microstructure. The flexible nanosized NaMnt platelets form a continuous structure with dispersed kaolin particles, resulting in various unique particle interaction configurations. The study also reveals the thixotropic and rheopectic behaviors of a 15.5 wt% gel with a 1:2 mass ratio of NaMnt to kaolin. Evaluation of the gel's structural development kinetics and aging behavior further provide insights into the formation process of continuous structures. Rating: 8/10.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Engineering, Geological
Yanchao Xue, Tao Xu, Michael J. Heap, Philip G. Meredith, Thomas M. Mitchell, P. L. P. Wasantha
Summary: This paper investigates the effects of single open macrofractures of differing orientations on time-dependent cracking and brittle creep in sandstone through laboratory experiments using digital image correlation (DIC). The results show that the failure of macrofractured sandstone under a constant stress is accompanied by the generation of more tensile fractures than in constant strain rate experiments. The nucleation site for the wing cracks depends on the fracture inclination angle, and the secondary crack behavior varies with the fracture angle and lateral shear direction. Creep bursts are more easily triggered in macrofractured rock and coincide with the coalescence of secondary cracks.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Geochemistry & Geophysics
Peng Dong, Rong Chen, Kaiwen Xia, Wei Yao, Zhigang Peng, Derek Elsworth
Summary: This study investigates dynamically triggered earthquakes on laboratory faults and reveals that the triggering process has two distinct phases, with a slow phase only present for a specific seismic condition and absent for supershear events.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Energy & Fuels
Fuchao Tian, Zhengdong Liu, Wancheng Zhu, Weiwei Su, Jiaxuan Wang, Jiamei Yang, Zheng Zhang
Summary: This study investigates the dynamic combined effect of coal mass diffusion and seepage on methane migration under different in situ stress conditions. By constructing the physical structure model of coal mass under high and low stresses and obtaining the diffusion parameters of coal mass, the methane migration in coal mass was calculated using a coupled multifield model. The results demonstrate that the extraction difficulty of methane is directly proportional to stress, and there is a significant discrepancy in methane migration under high and low stresses. A joint technical method for promoting methane flow rate under multicoal seam conditions is proposed based on the controlling factors in methane migration.
Review
Energy & Fuels
Qi Gao, Jishan Liu, Yee-Kwong Leong, Derek Elsworth
Summary: The significant effects of gas sorption induced swelling on shale permeability have been studied through laboratory measurements and explained using permeability models. However, there are lab observations that cannot be explained by these models, leading to a knowledge gap. In this review, the authors aim to resolve this gap by assessing the role of swelling on shale permeability through data collection, model classification, and correlation assessments. The findings suggest that discrepancies between model predictions and lab measurements depend on various factors, including the relationship between bulk and pore swelling strains, pore size scales, and consistency of strain treatments. The authors propose that future research should focus on characterizing the transformation between bulk and pore swelling strains, considering shale multiscale pore structural characteristics, and incorporating the time-dependent nature of swelling strain and permeability evolution.
Article
Energy & Fuels
Zhao Yaoyao, Zhao Yixin, Liu Jishan, Wei Mingyao, Cui Dongxue, Gao Sen
Summary: Permeability is a key parameter for evaluating the ability of coal reservoirs to transmit coalbed methane. The deformations of coal caused by physical field variations control the permeability evolution, and there is obvious non-uniformity in the deformations due to coal heterogeneity. However, the relationship between non-uniform deformation and permeability is unclear. This study conducted experiments to measure the permeability and deformations of a coal sample under different boundary conditions and injection pressures. The results showed anisotropic mechanical properties of the coal sample and differences in deformations between coal bulk and fractures.
Article
Environmental Sciences
Wenxing Wang, Weiyu Huang, Xiufeng Zhang, Wancheng Zhu, Shihao Guo, Ang Li
Summary: During hydraulic fracturing, exogenous microorganisms enter the shale gas reservoir, but the effects of microbial activity on the process are not well understood. In a laboratory simulation, a brine-shale-microorganism interaction was studied for 150 days. Biogenic methane production was rapid in the initial 16 days, slowed down from day 16 to day 40, and ceased after day 40, accompanied by alkalization of the brine. The formation of biogenic methane appeared to be independent of substrate type. This study also found that biofilms accelerated mineral dissolution, facilitated secondary mineral formation, and enhanced the complexity and heterogeneity of macropore structure.
GEOMICROBIOLOGY JOURNAL
(2023)
Article
Engineering, Geological
Yang Yuan, Tao Xu, Philip G. Meredith, Thomas M. Mitchell, Michael J. Heap, Guanglei Zhou, Ashley Stanton-Yonge Sesnic
Summary: In this study, an anisotropic damage microplane model that combines continuum damage mechanics with the classic microplane model is proposed to capture the anisotropy of rock properties in different orientations. The model's stress tensor is dependent on the integration of microplane stresses in all orientations and the damage state is determined by the microplane that satisfies the maximum tensile stress criterion or Mohr-Coulomb criterion. The proposed model is validated through laboratory experiments on brittle materials with orientated cracks and granite under true triaxial compression.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Jianwei Tian, Jishan Liu, Derek Elsworth, Yee-Kwong Leong
Summary: In this study, a 3D discrete fracture model (DFM) was proposed to represent the distribution of natural fractures (NFs). Gas flow in shale matrix was represented by a dual-fractal permeability model (DFPM). A hybrid DFPM-DFM model was proposed to couple gas flow and geomechanics and solved using finite element method. The model was verified with field data and used to investigate the impacts of fractally-distributed pore size and fracture attributes on permeability evolution and gas production.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Multidisciplinary
Xian-yang Yu, Tao Xu, Michael J. Heap, Zhen Heng, P. G. Ranjith, Boyi Su, P. L. P. Wasantha, Guanhua Sun
Summary: Investigating the correlation between internal crack propagation in rock and external time-dependent damage and failure of rock is crucial for understanding the long-term stability of engineering rock mass. A time-dependent virtual crack model is proposed to study the continuous-discontinuous deformation progress of rock. The model's simulated stress-strain curves for granite agree well with experimental data. The model is also applied to analyze the stability of a slope in the Xiaowan Hydropower Station, and the simulation results show good agreement with in-situ measurements, suggesting the current stability of the slope.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Review
Energy & Fuels
Bashirul Haq, Nasiru Salahu Muhammed, Jishan Liu, Hui Tong Chua
Summary: This critical review comprehensively examines the technical aspects of carbon dioxide enhanced gas recovery (CO2-EGR) for hydrogen production. The study finds that high pressure and moderate injection rates can improve EGR, while heterogeneous reservoirs tend to yield lower recovery rates. Factors such as flow rate, pressure, temperature, connate water, brine saturation, shale content, and the type of fluid phase used for injection significantly affect the molecular diffusivity of the injected gas and subsequent recovery outcomes. Simulation studies highlight the potential of injecting various gases with proper reservoir operation timing to enhance recovery and enable sustainable hydrogen production.
Article
Energy & Fuels
Yaoyao Zhao, Yixin Zhao, Jishan Liu, Mingyao Wei, Yifan Huang, Chuanzhong Jiang
Summary: In this study, a new multi-physical field coupling model was established to accurately predict the non-uniform deformation between coal bulk and fractures. Three kinds of non-uniform deformation indexes were defined and the theoretical solutions of the model were validated with experimental results. Additionally, the concept of modified effective stress was proposed to address the inconsistency between theoretical and experimental permeability solutions under constant effective stress condition.
Article
Geosciences, Multidisciplinary
Michael J. Heap, Claire E. Harnett, Tofig Nazarbayov, Zhen Heng, Patrick Baud, Tao Xu, Marina Rosas-Carbajal, Jean-Christophe Komorowski
Summary: The collapse of lava domes is caused by the inherent heterogeneity of the rock structure. Previous models have incorporated heterogeneity as discrete zones with homogeneous properties, but our study shows that the diffusion heterogeneity within these zones can also contribute to dome instability. Therefore, future models should consider both discrete zones and diffusion heterogeneity.
BULLETIN OF VOLCANOLOGY
(2023)
Article
Energy & Fuels
Qi Gao, Jishan Liu, Yaoyao Zhao, Mingyao Wei, Yee-Kwong Leong, Derek Elsworth
Summary: Approximately 20% of global natural gas resources may be microbial in origin, leading to significant interest in extracting biogenic gas from coal seams. Previous studies have shown that this can be achieved through injecting nutrients solution into a coal reservoir, stimulating microbial growth and enhancing biodegradation of organic components into methane gas. In this study, a modeling tool is developed to validate this concept under laboratory and reservoir conditions, coupling various physical and biological processes. The model is verified against experimental data and applied to simulate practical operations, demonstrating the effectiveness of coal-to-methane bioconversion and extraction.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Zhengdong Liu, Xinhui Chen, Fuchao Tian, Wancheng Zhu, Ze Hu, Weiwei Su, Zhiquan Wang
Summary: Fractures in coal seams play a crucial role in gas migration and their geometric characteristics can affect permeability, thus impacting coalbed methane (CBM) extraction and carbon dioxide sequestration. Previous research has mainly focused on surface characteristics of rough fractures, with less attention given to the dynamic effects of rough structure in fractures during different stages of methane extraction. In this study, a physical model of fracture rough elements was constructed and a definition of effective fracture aperture was proposed. By considering the competition between effective stress and matrix adsorption expansion, the change of effective fracture aperture related to pore pressure was determined. A permeability evolution model was formulated and compared with numerical simulations for verification. The findings indicate that fractures with smaller roughness, higher stagger degree, and gentler inclination angle of rough elements are more favorable for CBM extraction.
GAS SCIENCE AND ENGINEERING
(2023)