Characterization Of Internal Structure Research Articles

Development Characteristics and Genetic Analysis of Sand-bodies in Taiyuan Formation of Eastern Ordos Basin

On the basis of fully understanding the regional geological background, the changes of lithology, bedding type and sedimentary facies sequence are analyzed according to core, logging and logging data。The three sets of sandstones and their internal structural characteristics of Taiyuan Formation in Ordos Basin are defined. Qiaotou sandstone body is mainly developed in delta distributary channel, which is characterized by large thickness and wide distribution of sandstone body and multi-stage channel superimposition. Malan sandstone and Qiligou sandstone are mainly developed in submarine distributary channel of marine delta. They are relatively small in distribution scale, complex in internal structure of sand bodies, single massive sand bodies or composite sand bodies with thin mudstone interbeds. There are sand dams controlled by marine delta in Taiyuan Formation, which have different shapes and poor continuity. Based on the above results, it is considered that the sand body characteristics are mainly affected by paleo structuer topography, sedimentary environment and local uplift. These understandings are of great significance for judging the development position of high-quality reservoirs in sand bodies and improving the actual effect of oil and gas exploration and development in reservoir sand bodies.

Mesoscopic structure PFC∼2D model of soil rock mixture based on digital image

Soil-rock mixture (S/RM) is a very complex discontinuous medium material, which is a multiphase system consisting of high strength rock blocks (Rocks), relatively soft filling components (Soils) and corresponding pores. Because the mechanical properties of various components of soil-rock mixtures under external loads are very different, and there are extremely complex interactions between them. Therefore, the mechanical properties of this geotechnical material (such as stress transfer, failure mode, crack propagation, bearing capacity, etc.) are quite different from those of homogeneous geotechnical materials, and largely depend on the internal structure characteristics of soil-rock mixtures (such as particle size composition, particle shape, particle distribution and arrangement). Due to the complexity of the model, the simulation of its meso-mechanical properties is mostly confined to the random simulation of regular blocks. In this paper, an automatic generation method of PFC∼2D numerical model of soil-rock mixture microstructure based on digital image processing is proposed, and the experimental simulation is carried out with matlab. Thus, the rapid, real and automatic modeling of heterogeneous material microstructure by PFC∼2D software is realized. The PFC∼2D numerical calculation model of soil-rock mixtures is established. The results show that when the stone content is 80%, the analysis should be caused by the large amount of rock, which leads to the large internal voids, and the sudden unloading between the rock and the rock during compaction and then the structural reorganization.

Construction of simulation models of lunar observations

The aim of the present paper is to establish optimal parameters for simulation models of the lunar telescope. Modelling of the observations taken from the surface of the Moon is carried out on the basis of dynamic algorithms describing diurnal motion of stars and specifically designed software modules. The first steps in the development of simulation models were made when planning the ILOM (In-Situ Lunar Orientation Measurement) mission which implied the installation of an optical telescope on one of the lunar Poles. The main task of the project was to observe physical libration of the Moon directly from its surface in order to reveal subtle effects related to the characteristics of internal structure of our natural satellite, including the refinement of the Lava elasticity coefficients, tidal dissipation and dissipation at the core-mantle boundary parameters, core’s size, ellipticity, and its chemical composition. The results obtained in this work allow for the development of lunar physical libration and dynamics theory in order to apply them in the future lunar observations taken with the automated optical telescope.

Groundwater flow and storage processes in an inactive rock glacier

AbstractGroundwater flow through coarse blocky landforms contributes to streamflow in mountain watersheds, yet its role in the alpine hydrologic cycle has received relatively little attention. This study examines the internal structure and hydrogeological characteristics of an inactive rock glacier in the Canadian Rockies using geophysical imaging techniques, analysis of the discharge hydrograph of the spring draining the rock glacier, and chemical and stable isotopic compositions of source waters. The results show that the coarse blocky sediments forming the rock glacier allow the rapid infiltration of snowmelt and rain water to an unconfined aquifer above the bedrock surface. The water flowing through the aquifer is eventually routed via an internal channel parallel to the front of the rock glacier to a spring, which provides baseflow to a headwater stream designated as a critical habitat for an at‐risk cold‐water fish species. Discharge from the rock glacier spring contributes up to 50% of basin streamflow during summer baseflow periods and up to 100% of basin streamflow over winter, despite draining less than 20% of the watershed area. The rock glacier contains patches of ground ice even though it may have been inactive for thousands of years, suggesting the resiliency of the ground thermal regime under a warming climate.

Transport properties of concrete-like granular materials interacted by their microstructures and particle components

Granular materials as typical soft matter, their transport properties play significant roles in durability and service life in relevant practical engineering structures. Physico-mechanical properties of materials are generally dependent of their microstructures including interfacial and porous characteristics. The formation of such microstructures is directly related to particle components in granular materials. Understanding the interactive mechanism of particle components, microstructures, and transport properties is a problem of great interest in materials research community. The resulting rigorous component-structure-property relations are also valuable for material design and microstructure optimization. This review article describes state-of-the-art progresses on modeling particle components, interfacial and porous configurations and incorporating these internal structural characteristics into modeling transport properties of granular materials. We mainly focus on three issues involving the simulation for geometrical components, the quantitative characterization for interfacial and porous microstructures, and the modeling strategies for diffusive behaviors of granular materials. In the first aspect, in-depth reviews are presented to realize complex morphologies of geometrical particles, to detect the overlap between adjacent nonspherical particles, and to simulate the random packings of nonspherical particles. In the second aspect, we emphasize the development progresses on the interfacial thickness and porosity distribution, the interfacial volume fraction, and the continuum percolation of soft particles representing compliant interfaces and discrete pores. In the final aspect, a literature review is also provided on modeling of transport properties on the forefront of the effective diffusion and anomalous diffusion in multiphase granular materials. Finally, some conclusions and perspectives for future studies are provided.

Roles of Interfacial Tension in Regulating Internal Organization of Low Bandgap Polymer Bulk Heterojunction Solar Cells by Polymer Additives

AbstractThe role of a tertiary polymer‐based additive is investigated in increasing the efficiency of inverted low bandgap polymer:fullerene bulk heterojunction (BHJ) solar cells. Charge separation in polymer BHJ solar cells relies on the phase separation between electron accepting fullerene derivatives and photoactive polymers. Proper distribution of individual phases of suitable crystallinities within the active layer is a key factor for efficient charge transport/extraction and high photovoltaic performance. Here, it is demonstrated that the minor addition of a tertiary amorphous polymer, polystyrene (PS), with optimized molecular weights can increase the overall photovoltaic efficiency of poly[N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)]:phenyl‐C61butyric acid methyl ester (PCDTBT:PCBM) inverted BHJ solar cells, through the interfacial‐tension‐driven increase in crystallinities of photoactive phases and redistribution of PCBM molecules away from the top hole‐collecting anode interface. Complementary studies correlating polymer interfacial tension, blend internal structure, charge transport, and photovoltaic characteristics show that tertiary, high molecular‐weight polymers can serve as effective additives for improving the performance of low bandgap polymer solar cells.

Countries Mimicking Neighbors: The Spatial Diffusion of Governmental Restrictions on Religion

AbstractConceptualized as efforts to deny religious freedoms, previous research explains the presence of governmental restrictions on religion by isolating national governments, asserting that the primary determinant is a country's internal structural characteristics. These approaches overlook why the levels of governmental restriction on religion are spatially clustered and increasing in distinct patterns. Utilizing spatial analysis and data from the Religion and State Project, this article demonstrates that governmental restrictions on religion are spatially clustered, not independent from neighboring countries, and that increases in a country's level of restrictions reflect similar changes in bordering countries. Spatial clustering emerges through the diffusion of policies, where national governments mimic their neighbor's policies and practices even when accounting for internal structural characteristics. The article concludes that while a country's internal structure is clearly a predictor of policies, national governments are not isolated from neighbors where the level of restrictions are susceptible to external influence.

Internal Structure and Item Characteristics of the Phonological Awareness Literacy Screening in Spanish for Preschool

We used multidimensional item response theory to test the internal structure of the Phonological Awareness Literacy Screening in Spanish for Preschool and test for item parameter drift. The measure is aligned with the simple view of reading, which defines reading as consisting of two equally important dimensions: decoding and language comprehension. It involves 134 items grouped into nine different tasks. We administered a pilot version of the measure to 677 students in 2014 and a final version to 968 students in 2015. We did not find evidence that code-related skills and oral language are distinct but correlated dimensions among preschoolers. Rather, a single general dimension of early literacy with task-related specific dimensions fit best. A benefit of our modeling approach is that we can examine the internal structure while also evaluating the difficulty and discrimination of individual items. Results suggest a stable ordering of items within tasks and that some Spanish letters are learned more easily than others.

Sınıf Öğretmenlerinin Fen Bilimleri Kılavuz Kitap Seçim Kriterlerinin Belirlenmesi

Bu araştırma, sınıf öğretmenlerinin fen bilimleri dersinde kullandığı yardımcı kaynakların seçiminde dikkate aldıkları kriterleri belirlemek amacıyla yapılmıştır. Araştırmada nicel araştırma yöntemlerinden tarama yöntemi kullanılmıştır. Araştırmanın evrenini Amasya il merkezinde görev yapmakta olan ve 3. ve 4. sınıfları okutan sınıf öğretmenleri oluşturmaktadır. Araştırmanın örneklemini 102 sınıf öğretmenini kapsamıştır. Veri toplama tekniği ankettir. Öğretmenlerin kılavuz kitap seçim kriterlerini belirlemek için literatürden faydalanılarak kitap seçim kriterleri ölçeği hazırlanmıştır. Ölçek 70 maddeden ve dış yapı, iç yapı ve eğitsel özellikler alt boyutlarından oluşmaktadır. SPSS 15.0 programı kullanılarak verilerin betimsel ve yordamsal analizleri yapılmıştır. Öğretmenler ders kitabı dışında en çok internet ve yaprak testlerden yararlandıkları, kılavuz kitapları konu açıklamada kullandıklarını belirtmişlerdir. Ölçekte en yüksek ortalama puan eğitsel özellikler boyutunda bulunmuştur. Öğretmenlerin genel olarak“katılıyorum” düzeyinde olumlu görüş bildirdikleri bulunmuştur. En yüksek ortalamalar kitabın konuyu açıklaması, öğrenciye uygunluğu ve bilgilerin konu alanına uygunluğu maddelerinde bulunmuştur. Kitap seçim kriterleri ölçeği toplam puanları öğretmenlerin cinsiyet ve mesleki kıdemine göre anlamlı farklılık göstermemektedir.

The Juchatengo complex: an upper-level ophiolite assemblage of late Paleozoic age in Oaxaca, southern Mexico

The Juchatengo complex (JC) suite is located between the Proterozoic Oaxacan complex to the north and the Xolapa complex to the south, and was amalgamated by late Paleozoic magmatism. It consists of mafic and sedimentary rocks that have oceanic affinities, with internal pseudostratigraphic, structural and metamorphic characteristics, which resemble a typical upper-level ophiolite assemblage. New U–Pb zircon and previous hornblende K–Ar analyses yield ages of ca. 291–313 Ma (U–Pb) for plagiogranites and ca. 282–277 Ma for tonalites intruding the entire sequence, including pelagic sediments at the top, with a maximum deposition age of ca. 278 Ma and noteworthy local provenance. These data constrain the age of the JC to the Late Pennsylvanian–Early Permian period. Hf isotopic analyses obtained from zircons in the JC plagiogranite and tonalite show that they come from a similar primitive mantle source (176Hf/177Hf: 0.282539–0.283091; ƐHf(t): + 3.2 to + 15.0). ƐHf(t) values from near 0 to − 2.8 in the tonalites indicate a contribution from the continental crust. Trace elements and REE patterns in whole rock and zircons point to a primitive mantle source for differentiated mafic, plagiogranite dykes and tonalitic plutons. Geochronological and geochemical data address the generation of new oceanic crust above the subduction zone, probably in a backarc setting. In this tectonic scenario, the JC ophiolite originated due to the convergence of the paleo-Pacific plate below the already integrated Oaxacan and Acatlan complexes in western Pangea. The dextral displacement places the deformation in a transtensional regime during the late Paleozoic age.

Porosity Estimation from High Resolution CT SCAN Images of Rock Samples by Using Housfield Unit

Computer Automated Tomography has been shown to be a valuable tool in production research because it provides a non-destructive method to identify and evaluate the internal structural characteristics of reservoir rock. In CT scan, Hounsfield Unit (HU) is proportional to the degree of X-ray attenuation by the tissue. The aim of the present study was to introduce the method to estimate porosity which is one of physical parameters of reservoir rock though HU data. In this study, an Image J software was used to extract Hounsfield Unit data and calibrate by standard material’s density. This method provides the ability of using CT Scanner in advanced reservoir characterization and flow test experiments.

Recast Layer Thickness Characterization of Array of Micro Features Using X-Ray Micro Computed Tomography

Destructive characterization of recast layer on reverse micro EDM-ed (RMEDM) surface renders the component unusable for its intended application. X-ray micro computed tomography (µCT) is a non-destructive technique widely used for characterization of internal structures of different materials. Array of hemispherical shaped micro features fabricated by RMEDM by employing taper ended blind holes led to variation in recast layer thickness of the micro features both along its length and position on the surface of workpiece. µCT characterization of recast layer thickness revealed that with respect to location on micro feature, the tip of micro feature had the highest recast layer thickness and the base the lowest. Also, with respect to location of micro feature on the surface of workpiece, the micro feature at the periphery had the lowest recast layer thickness whereas the micro feature at the centre had the highest.

Association Rules between the Microstructure and Physical Mechanical Properties of Rock-mass under Coupled Effect of Freeze-thaw Cycles and Large Temperature Difference

The mechanical properties of fractured rock mass are largely dependent on the fracture structure under the coupling of freeze-thaw cycles and large temperature difference. Based on the traditional macroscopic continuum theory, the thermal and mechanical model and the corresponding theories ignore the material internal structure characteristics, which add difficulty in describing the mesoscopic thermal and mechanical behavior of the fractured rock mass among different phases. In order to uncover the inherent relationship and laws among the internal crack development, structural change and the physical and mechanical properties of rock under strong cold and frost weathering in cold area, typical granite and sandstone in cold region were analyzed in laboratory tests. The SEM scanning technology was introduced to record the microstructural change of rock samples subject to freeze-thaw cycles and large temperature difference. Association rules between the microstructure and the physical mechanical properties of rock mass were analyzed. The results indicated that, with the increase of the cyclic number, the macroscopic physical and mechanical indexes and the microscopic fracture index of granite and sandstone continuously and gradually deteriorate. The width of original micro crack continues to expand and extend and new local micro cracks are generated and continue to expand. The fracture area and width of the rock increase and the strength of the rock is continuously damaged. In particular, the strength and elastic modulus of granite decrease by 20.2% and 33.36%, respectively; the strength and elastic modulus of sandstone decrease by 33.4% and 36.43%, respectively.

Acquiring high-resolution topography and performing spatial analysis of loess landslides by using low-cost UAVs

The Loess Plateau is a region in China prone to frequent geological disasters, where thousands of loess landslides can be found. Conventional field survey methods are inadequate for the requirements of fine spatial analysis of landslides. Due to its numerous advantages (fast, efficient, low cost, safe, and able to acquire high-resolution data), structure from motion (SfM) technique to photogrammetric orientation of flights and modeling applied to photographs taken by unmanned aerial vehicles (UAVs) equipped with a camera has become a powerful new tool for the generation of high-resolution topography that has emerged in recent years, which has become a powerful new technique for acquiring high-resolution topographic data. In this study, we conducted nearly two months of field UAV surveys of loess landslides on the Loess Plateau, eventually established 3D digital models for 11 loess landslides, and produced high-resolution digital orthophoto maps (DOMs) and digital elevation models (DEMs). High-resolution spatial analysis of the loess landslides (mainly including characteristic parameter extraction, topography profile analysis, surface feature analysis, and hydrologic analysis) was performed using Agisoft PhotoScan, ArcGIS 10.2, Global Mapper 17, and Origin Pro 9.0. The UAV technique allows us to further understand the micro-level internal spatial and structural characteristics of loess landslides. Moreover, not only does it allow us to accurately measure the characteristic geometric parameters but also enables us to detect the surface details of loess landslides (e.g., textures, fissures, and micro-landforms). Manifestly, we can also deduce the original structural characteristics and possible inducement mechanism of landslides based on a combination of high-resolution data acquired by UAVs, proper ground surveys, and theoretical knowledge. In summary, the low-cost UAVs are highly and especially suitable for surveys and digital terrain analysis of landslides on the Loess Plateau with sparse vegetation.

Production of Composite Scaffold Containing Silk Fibroin, Chitosan, and Gelatin for 3D Cell Culture and Bone Tissue Regeneration.

BackgroundBone tissue engineering, a powerful tool to treat bone defects, is highly dependent on use of scaffolds. Both silk fibroin (SF) and chitosan (Cs) are biocompatible and actively studied for reconstruction of tissue engineering. Gelatin (Gel) is also widely applied in the biomedical field due to its low antigenicity and physicochemical stability.Material/MethodsIn this study, 4 different types of scaffolds were constructed – SF, SF/Cs, SF/Gel, and SF/Cs/Gel – and we compared their physical and chemical properties as well as biological characterization of these scaffolds to determine the most suitable scaffold for use in bone regeneration. First, these scaffolds were produced via chemical cross-linking method and freeze-drying technique. Next, the characterization of internal structure was studied using scanning electron microscopy and the porosity was evaluated by liquid displacement method. Then, we compared physicochemical properties such as water absorption rate and degradation property. Finally, MC3T3-E1 cells were inoculated on the scaffolds to study the biocompatibility and osteogenesis of the three-dimensional (3D) scaffolds in vitro.ResultsThe composite scaffold formed by all 3 components was the best for use in bone regeneration.ConclusionsWe conclude that the best scaffold among the 4 studied for MC3T3-E1 cells is our SF/Cs/Gel scaffold, suggesting a new choice for bone regeneration that can be used to treat bone defects or fractures in clinical practice.

Rural settlements transition (RST) in a suburban area of metropolis: Internal structure perspectives

Rural settlements transition (RST) is one of the most significant indices for understanding the phenomena of rural reconstruction and urban-rural transformation in China. However, a systematic overview of RST is missing, and there is a lack of evidence regarding its characteristics from the internal structure perspectives. In this paper, we systematically explore the RST regarding spatio-temporal change characteristics of internal structure, patterns and impacts on rural environment and development by using practical survey internal land-use data from 2005 to 2015. The results show that the temporal change characteristics of the internal structure of rural settlements demonstrate a tendency for housing land to decrease and other land-use types to increase. The spatial change characteristics reveal that the structure inclines to more complexity and diversity from an exurban area to an urban-rural fringe area. Based on this finding, we identify that rapid development of rural industrialization, more agglomerate and effective industrial land-use, and improved public infrastructure construction are the general RST patterns. Spatially, there exists a physical decay pattern in the exurban area, thereby resulting in the hollowing-out of rural industries and of the population. In addition, the extensive and disorderly pattern in the suburban area causes low efficiency output and serious environmental pollution. The RST pattern in the urban hinterland promoted the “men-environment” compatible development. The study concludes that regional differentiation in patterns and impacts are significant in the process of RST. Future adaptive strategies for rural settlements adjustment should be conducted according to regional characteristics, including socio-economic status, physical geography condition and economic location to improve the rural environmental sustainability.

Experimental Study on Failure Characteristics of Schist Under Unloading Condition

The mechanical properties of rock under unloading condition have significant differences with those under conventional loading condition. To investigate the failure characteristics of schist under complex stress state, uniaxial and trixial compression and unloading confining pressure tests have been carried out on samples in the paper. The results show that the rock samples failed in coupling mode of shear and tension under uniaxial compression, and failed in shear mode under conventional trixial compression. However, the failure modes of the samples can be classified as shear, multiple fracturing, and multiple extension, and the strength of schist is closely related with the failure mode under unloading confining condition. For the unloading condition, the peak strengths of schist samples with shear failure mode are close to those under conventional trixial compression, but the peak strengths with multiple fracturing or multiple extension mode are much higher than those under trixial compression. The internal structure characteristics and stress paths were found to have major influences on the failure modes of schist. Therefore, the failure modes must be considered when the strength characteristics of schist are investigated.

Cell wall changes in Actinidia arguta during softening

Abstract Actinidia arguta fruit, differing from conventional kiwifruit A. chinensis ‘Hort16A’ and ‘Hayward’ by size, skin appearance, softening rate and texture, were characterised regarding structural and cell wall changes during softening. Cell wall changes of A. arguta var. arguta ‘Hortgem Tahi’ were examined during softening using histological stains, immunolocalisation and cell wall composition analyses. ‘Hortgem Tahi’ fruit are bite-sized and have a skin that is considered edible by consumers, consisting of a cuticle, a living epidermis and a hypodermis of tightly packed thin-walled cells, containing condensed phenolic material. Beneath is the outer pericarp with large and small parenchyma cells, followed by the inner pericarp with seed-containing locules, and core tissue consisting of small, tightly packed parenchyma cells. Throughout the fruit are large numbers of mucilage-containing cells. At harvest, cell walls stain densely with toluidine blue; as fruit softens, staining is lost in the outer pericarp but retained in the epidermis and hypodermis. At harvest, antibodies directed to cell wall epitopes bind to cell walls with a characteristic labelling pattern, but later as fruit soften these antibodies also label polysaccharides inside the cells. ‘Hortgem Tahi’ softens within five days after harvest. Cell wall composition analyses showed that during the softening process, galactose loss as well as pectin solubilisation started at an earlier firmness stage compared to ‘Hayward’ fruit that take about thirty days to soften. ‘Hortgem Tahi’ shows similar internal structural characteristics and cell wall changes compared with conventional kiwifruit. However, they differ in skin structure, the presence of mucilage filled cells, and the occurrence of pectin labelling within the lumen of cells at the ripe fruit stage which may be responsible for the gelatinous texture of the ripe fruit. The comparatively fast softening rate may be caused by an early reduction of galactose content increasing cell wall porosity that supports pectin solubilisation.

Природа циркона в габбро Волковского массива (Средний Урал): проблема возраста и геохронологические следствия

The article presents new isotope-geochemical data on zircon from gabbronorites of the Volkovsky massif in the Middle Urals. The massif is a complex combination of different rock associations - from ultramafic rocks to syenites and quartz diorites, whose geological and geochronological ratios are not well-defined yet. The most widespread in the massif are gabbroids, which form three blocks - the Central, Western and Southern ones. This massif is associated with: 1) industrial deposit of copper-iron-vanadium ores and 2) gold-palladium mineralization of low sulfide type. Gabbronorites, which form peripheral parts of the gabbro blocks and in some cases form dykes among olivine gabbro, have a dual relationship with mineralization. They are host for copper-iron-vanadium type and postmineral concerning the gold-palladium mineralization localized in ultramafic rocks and olivine gabbro of the Southern block. The comprehensive study of zircon (its morphology, internal structure, U-Pb age, and silicate inclusions) has shown that in gabbronorites of the Volkovsky massif, zircon aged 427.5 ± 5.3 Ma and 428 ± 7 Ma, extracted from two different samples, contains the same set of polymineral inclusions, alien to the hosting rocks. The composition of inclusions (plagioclase ( An 21), biotite (f = 0.49-0.56), quartz and apatite) corresponds to gneiss or plagiogranite. However, the zircon, according to its morphology, internal structure and age characteristics is similar to that from metamorphic rocks of the dynamothermal halo of gabbro-ultramafic bodies. This suggests that the zircon in gabbronorites of the Volkovsky massif could be borrowed from the surrounding metamorphic rocks, and therefore, the gabbronorite intrusion occurred when high-temperature metamorphic rocks of the dynamothermal halo had already existed and might have undergone anatexis and retrogressive metamorphism of amphibolite facies. The zircon age (≈427 Ma) limits the lower time limit of the formation of gabbronorite intersecting olivine gabbro of the Volkovsky massif, and may be close to the time of the formation of copper-iron-vanadium and gold-palladium mineralization type controlled by the reaction processes between gabbronorites and olivine gabbro.

Effects of water saturation on P-wave propagation in fractured coals: An experimental perspective

Internal structure of coalbed methane (CBM) reservoirs can be evaluated through ultrasonic measurements. The compressional wave that propagates in a fractured coal reservoir may indicate the internal coal structure and fluid characteristics. The P-wave propagation was proposed to study the relations between petrophysical parameters (including water saturation, fractures, porosity and permeability) of coals and the P-wave velocity (Vp), using a KON-NM-4A ultrasonic velocity meter. In this study, the relations between Vps and water saturations were established: Type I is mainly controlled by capillary of developed seepage pores. The controlling factors on Type II and Type III are internal homogeneity of pores/fractures and developed micro-fractures, respectively. Micro-fractures density linearly correlates with the Vp due to the fracture volume and dispersion of P-wave; and micro-fractures of types C and D have a priority in Vp. For dry coals, no clear relation exists between porosity, permeability and the Vp. However, as for water-saturated coals, the correlation coefficients of porosity, permeability and Vp are slightly improved. The Vp of saturated coals could be predicted with the equation of Vp-saturated=1.4952Vp-dry–26.742m/s. The relation between petrophysical parameters of coals and Vp under various water saturations can be used to evaluate the internal structure in fractured coals. Therefore, these relations have significant implications for coalbed methane (CBM) exploration.