Imaged based fractal characterization of micro-fracture structure in coal

We acknowledge financial support from the National Natural Science Foundation of China (41830427; 41472137), the Petro China Innovation Foundation (2018D-5007-0101), the Key research and development project of Xinjiang Uygur Autonomous Region (2017B03019-1), the Royal Society Edinburgh and National Natural Science Foundation China (NSFC 41711530129), and the Foreign Experts’ Recruiting Program from the State Administration of Foreign Experts Affairs P.R. China.Peer reviewedPostprin

Developing force field parameters for water interacting with graphene and graphene-like materials

Confined water can have properties dramatically different from bulk water, and these properties can be used to develop unique functionality at the nanoscale. For example, fast water transport, rotation-translation coupling, and fast rotationalmotion have been observed in graphitic carbon-based nano structures, which enables various applications like energy storage and seawater desalination. The explosive studies on graphene have sparked new interests towards graphene-analogous materials including hexagonal boron nitride (hBN) and molybdenum disulfide (MoS2). Compared to graphene, the graphene-analogous materials possess non-zero bandgap, chemical inertness, and biological compatibility. The graphene-analogous materials are promising materials, complementary to graphene, for high-temperature, biomedical and nanofluidic applications. We would like to understand and optimize graphene and graphene-analogous materials in these applications. The study of graphene and graphene-analogous materials at the atomic level requires accurate force field parameters to describe the water-surface interaction. We begin with benchmark quality first principles quantum Monte Carlo (QMC) calculations on the interaction energy between water and surface, which are used to validate random phase approximation (RPA) calculations. We then proceed with RPA to derive force field parameters, which are used to simulate properties like water contact angle on the surface, attaining a value within the experimental uncertainties. This work demonstrates that end-to-end multiscale modeling, starting at detailed many-body quantum mechanics, and ending with macroscopic properties, with the approximations controlled along the way, is feasible for these systems

Analyses of representative elementary volume for coal using X-ray μ-CT and FIB-SEM and its application in permeability predication model

We acknowledge financial support from the National Natural Science Foundation of China (41872123; 41830427), the Petro China Innovation Foundation (2018D-5007-0101), the Key research and development project of Xinjiang Uygur Autonomous Region (2017B03019-1), the Royal Society Edinburgh through the international cost share scheme and National Natural Science Foundation China (NSFC 41711530129).Peer reviewedPostprin

Toxic effects of iron oxide nanoparticles on human umbilical vein endothelial cells

Iron oxide nanoparticles (IONPs) have been employed for hyperthermia treatments, stem cell therapies, cell labeling, and imaging modalities. The biocompatibility and cytotoxic effects of iron oxide nanoparticles when used in biomedical applications, however, are an ongoing concern. Endothelial cells have a critical role in this research dealing with tumors, cardiovascular disease and inflammation. However, there is little information dealing with the biologic effects of IONPs on the endothelial cell. This paper deals with the influence of dextran and citric acid coated IONPs on the behavior and function of human umbilical vein endothelial cells (HUVECs). After exposing endothelial cells to IONPs, dose-dependent effects on HUVECs viability, cytoskeleton and function were determined. Both citric acid and dextran coated particles appeared to be largely internalized by HUVECs through endocytosis and contribute to eventual cell death possibly by apoptosis. Cytoskeletal structures were greatly disrupted, as evidenced by diminished vinculin spots, and disorganized actin fiber and tubulin networks. The capacity of HUVECs to form a vascular network on Matrigel™ diminished after exposure to IONPs. Cell migration/invasion were inhibited significantly even at very low iron concentrations (0.1 mM). The results of this study indicate the great importance of thoroughly understanding nanoparticle-cell interactions, and the potential to exploit this understanding in tumor therapy applications involving IONPs as thermo/chemoembolization agents

Application of Wireless Communication and GIS in Agricultural Environment Monitoring

The SMS/GPRS technology and seamless integration of GIS technology were used to implement remote data real-time transmission and management analysis in agricultural environment monitoring. Through SMS/GPRS technology this system realized wireless real-time transmission of remote monitoring data. Based on the GIS visualization technology and spatial analysis the monitoring data were displayed visually as well as location of pollution area was realized. System mainly consists of three modules: monitor communication center, information center and GIS environment monitoring information management. The overall design system in fully reflects the GIS, wireless transmission, environment monitoring seamless integration of the three modules. Development language is Visual Studio2005 VC.NET comprehensive use of MFC and CRL and Oracle9i database is adapted to integratedly access attribute data and the of spatial data, using MapX component to implement map visualization display and spatial geographical analysis. The system is suitable for departments of agriculture to acquire and communicate the environmental monitoring data, to manage the GIS, and to analyze the decision

Remote Sensing Monitoring System of Land Coverage Change in Mining Area

Based on remote sensing images, the panoramic views of land coverage distribution across a large geographic area can be accessed conveniently. Remote sensing monitoring system of land coverage change in mining area, which is a complex information system based on spatial database to manage multi-source heterogeneous data, was proposed in this article. The system structure, function and development strategy were studied in this paper. Remote sensing image fusion and classification are the key technologies in this system. The remote sensing image fusion method which is based on multi-band wavelet was discussed. Based on remote sensing image, the Chaos Immune Algorithm was proposed to improve the accuracy of land coverage classification. The results showed that this system can integrate the multi-source heterogeneous spatial data, including remote sensing image, vector data and related properties data into the whole body, also demonstrate graphical visualization and analyze compositely

Vibro-acoustic coupled analysis excited by correlated turbulent boundary layer

Vibro-acoustic coupling is one of the most concerned problems in the design stage of aircraft and aerospace vehicle. An algorithm that integrates the finite element method (FEM), the boundary element method (BEM) and an acquisition method of excitation correlation is proposed to conduct the vibro-acoustic coupled analysis under correlated excitations in time and spatial domains. The Corcos/Smol’yakov-Tkachenko (ST) power spectral density models are adopted for the correlated excitation with a divisional method, and the vibro-acoustic coupled analysis of complex structures can be greatly simplified. First, a simply supported panel under correlated TBL is investigated to validate the proposed algorithm. Then, the proposed algorithm is applied to a stiffened panel to carry out the vibro-acoustic coupled analysis under three types of excitation: (a) perfectly correlated TBL, (b) partially correlated TBL based on the Corcos or ST model, and (c) uncorrelated TBL. Parameters which may affect the vibro-acoustic coupled analysis, such as the coupled effect, the correlation of excitation and the speed and thickness of the turbulence, are also discussed. Results show that the proposed method is suitable for the vibro-acoustic coupled analysis of complex systems under correlated random excitations. The vibro-acoustic coupling effect will result in a decrease in both the natural frequency and structural response under perfectly correlated excitation, and an increase in the structural response for partial correlated and uncorrelated excitations. However, the coupling effect has little influence on the acoustical response. The structural and acoustic responses due to partially correlated excitation are larger than that due to perfectly correlated excitation. Moreover, the structural and acoustic responses increase with the increment in turbulence speed and thickness, and the difference among the responses under the three different types of excitations rapidly increase with the increasing of the turbulence speed