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Investigation of stability of a tunnel in a deep coal mine in China

International Journal of Mining science and Technology 2013年第4期23卷 567-577页

作者： Kulatilake P.H.S.W. Wu Qiong Yu Zhengxing Jiang Fuxing Geological Engineering Program Department of Materials Science & Engineering University of Arizona Faculty of Engineering China University of Geosciences China Academy of Safety Science and Technology School of Civil and Environmental Engineering University of Science and Technology Beijing

Stability level of tunnels that exist in an underground mine has a great influence on the safety,production and economic performance of *** of stability for soft-rock tunnels is an important task for deep coal mines located in high in situ stress *** the available information on stratigraphy,geological structures,in situ stress measurements and geo-mechanical properties of intact rock and discontinuity interfaces,a three-dimensional numerical model was built by using 3DEC software to simulate the stress conditions around a tunnel located under high in situ stress conditions in a coal rock mass in *** were conducted for several tunnel shapes and rock support *** obtained for the distribution of failure zones,and stress and displacement felds around the tunnel were compared to select the best tunnel shape and support pattern to achieve the optimum stability conditions.

关键词： Coal mine Tunnel stability High in situ stress Numerical modeling 3DEC

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THE CHEMICAL-POTENTIALS OF POLYMER SYSTEMS FROM COMPUTER-SIMULATIONS

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FLUID PHASE EQUILIBRIA 1993年第C期83卷 333-340页

作者： KUMAR, SK Department of Materials Science and Engineering Polymer Science Program Pennsylvania State University University Park PA 16802 U.S.A.

In an earlier publication we had presented a Monte Carlo method to calculate the incremental chemical potential between a chain of length nu and one of length nu+1 at any density (Kumar et al., 1991, Kumar, 1992a, 1992b). In this paper we begin by formally proving that the chemical potential of a whole chain of length nu can be obtained by sequentially summing the incremental chemical potentials of all chains whose lengths are smaller than nu under the same conditions. It was found that the incremental chemical potentials defined in this manner had a well defined chain length dependence, and that they were essentially independent of chain length in polymer melt systems. This allows us, in principle, to enumerate the phase diagrams for polymer blends using the incremental chemical potentials alone.

关键词： Polymer blends

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Improving the Performance of Asphalt Mixtures with Highly Acidic Aggregates in Central Vietnam Using Modifier Based on Styrene-Butadiene-Styrene and Rosin Resin

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Journal of materials in Civil engineering 2025年第7期37卷

作者： Nguyen, Lan Ngoc Lee, Hosin David Bui, Lam Tung Kim, Young-Ik Truong, Van Quyet Nguyen, May Huu Nguyen, Du Van Dept. of Construction Materials Faculty of Construction Engineering Univ. of Transport and Communications No. 03 Cau Giay Hanoi100000 Viet Nam Dept. of Civil and Environmental Engineering Iowa Technology Institute The Univ. of Iowa Iowa CityIA52242 United States Research Dept. Hansoo Natech Co. Ltd. 6-20 Yuseong-daero 1205beon-gil Yuseong-gu Daejeon34104 Korea Republic of Civil and Environmental Engineering Program Graduate School of Advanced Science and Engineering Hiroshima Univ. 1-4-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8527 Japan Faculty of Civil Engineering Univ. of Transport and Communications Campus in Ho Chi Minh City Ho Chi Minh City700000 Viet Nam

In Central Vietnam, the aggregate typically originates from highly acidic rocks containing a significant amount of silicon dioxide (SiO2), leading to poor adhesion quality with virgin asphalt binder. Hence, the asphalt mixture production usually needs to utilize adhesion promoters. Based on the chemical compositions of the sample aggregate (up to 72.3% SiO2), research has been conducted to introduce an adhesive agent called rubber modified compound (RMC-160), which is composed of styrene-butadiene-styrene (SBS) with petroleum hydrocarbon resin, treated clay and mineral oil. This article presents the research findings regarding the adhesion effectiveness of RMC-160-modified asphalt binder to high acid-based aggregate through laboratory and field tests, along with the mixture performance under both short-term oven aging (STOA) and long-term oven aging (LTOA). The test results exhibited remarkable effects, whereby the asphalt binder modified with RMC-160 additive significantly increased the adhesion level from Grade 2 to Grade 4, and the asphalt mixtures containing RMC-160 had lower rutting and higher cracking tolerance (CTIndex) under both the STOA and LTOA conditions. © 2025 American Society of Civil Engineers.

关键词： Silicon oxides

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CARBON-COATED ALUMINA AS A CATALYST SUPPORT .1. PREPARATION VIA LIQUID AND VAPOR-PHASE PYROLYSIS

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APPLIED CATALYSIS 1985年第3期16卷 375-388页

作者： BUTTERWORTH, SL SCARONI, AW Department of Materials Science and Engineering Fuel Science Program The Pennsylvania State University University Park PA 16802U.S.A.

The minimum loadings of carbon required to completely cover a pure phase γ-Al 2 O 3 catalyst support and a commercial HDS support were determined. Carbon was deposited from the liquid-phase carbonization of anthracene or the vapor-phase pyrolysis of propylene. Water adsorption was used to determine whether the Al 2 O 3 surface had been completely covered by carbon. Water vapor was adsorbed irreversibly on exposed Al 2 O 3 but reversibly on Al 2 O 3 surface covered by carbon. The liquid-phase experiments showed that the γ-Al 2 O 3 support surface was not completely covered for carbon loadings of less than 67 wt%. Calcining the coked supports had little effect on the surface coverage. Carbon deposited from the cracking of propylene at 101 kPa and 673 K completely covered the commercial HDS support at a loading of 5 wt%. The γ-Al 2 O 3 support was covered at a loading of 7 wt% from the cracking of 10.1 kPa propylene at 673 K. A slower carbon deposition rate was shown to favor more uniform surface coverage.

关键词： CATALYSTS

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Understanding the effect of preparation technique and compaction pressure on the microstructure, sinterability and mechanical properties of the Cu-20 wt% WC composite prepared with recycled WC

Journal of Alloys and Compounds Communications

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Journal of Alloys and Compounds Communications 2025年 6卷

作者： Rafael A. Raimundo Franciné A. Costa Marco A. Morales Daniel A. Macedo Angelus G.P. Silva Uílame U. Gomes Federal University of Paraíba Department of Materials Science and Engineering João Pessoa PB 58051-900 Brazil TEMA – Centre for Mechanical Technology and Automation Department of Mechanical Engineering University of Aveiro Aveiro 3810-193 Portugal Mechanical Engineering Postgraduate Program UFRN Natal 59078-970 Brazil Department of Theoretical and Experimental Physics UFRN Natal 59078-970 Brazil Materials Science and Engineering Postgraduate Program UENF Campos dos Goytacazes 28015-620 Brazil Materials Science and Engineering Postgraduate Program UFRN Natal 59078-970 Brazil

The study investigated the impact of different preparation techniques (Mechanical Mixing - MM and High Energy Milling - HEM) and compaction pressures on the microstructure, sinterability and mechanical properties of the Cu-20 %WC composite using recycled WC. The results indicated that HEM promotes greater homogeneity, dispersion and refinement of the WC phase in copper, resulting in denser and more uniform microstructures after sintering. Although higher pressures increased the density of green compacts, they reduced densification during sintering, especially for powders prepared by MM, due to the segregation of the Cu and WC phases. On the other hand, compacts sintered with HEM powders prsented higher Vickers microhardness and better magnetic properties, attributed to the uniform distribution of WC particles and the increase in the interaction between the phases. Furthermore, the study highlights the influence of metallic impurities (Fe, Co and Ni) on the magnetic properties of the composite materials.

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EFFECTS OF ORGANIC SULFUR-CONTENT ON THERMOLYSIS AND HYDROGENOLYSIS OF LIGNITES

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FUEL PROCESSING TECHNOLOGY 1990年第C期24卷 179-185页

作者： GARCIA, AB SCHOBERT, HH Fuel Science Program Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 U.S.A.

The reactions of lignites were investigated in nitrogen and hydrogen atmospheres in the absence of hydrogen donor solvent. Three lignites were chosen on the basis of widely differing contents of organic sulfur: Hagel (U. S. A.), 0.79%; Cayhiran (Turkish), 4.85%; and Mequinenza (Spanish), 11.3%. Reaction conditions were 275°C, 6.9 MPa gas pressure for 30 minutes. In the absence of a hydrogenation catalyst the conversions and liquid yields for a given lignite were the same regardless of the atmosphere. For the three lignites, the liquid yields correlated with the organic sulfur content. For catalytic hydrogenation, the lignites were impregnated with ammonium tetrathiomolybdate. In this case, higher conversions and liquid yields were obtained in a hydrogen atmosphere than in nitrogen. Both the absolute values of the liquid yields and the increase in yield in a hydrogen atmosphere relative to nitrogen correlated with the organic sulfur content. These results suggest that the thermolysis of relatively weak CS bonds is important in disrupting the macromolecular structure of these lignites, and that in the absence of solvent a dispersed catalyst is important in facilitating hydrogenolysis.

关键词： Lignite

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ON THE OXIDATION RESISTANCE OF C/C COMPOSITES OBTAINED BY LIQUID-PHASE IMPREGNATION CARBONIZATION OF DIFFERENT CARBON CLOTHS

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CARBON 1993年第5期31卷 789-799页

作者： RODRIGUEZMIRASOL, J THROWER, PA RADOVIC, LR [a]Fuel Science Program Department of Materials Science & Engineering The Pennsylvania State University University Park PA 16802 U.S.A.

Two commercial carbons (an activated carbon cloth and a rayon-derived carbon cloth) having vastly differing properties were used as substrates for the preparation of low- and high-temperature carbon/carbon composites by the liquid-phase impregnation/carbonization technique with two different pitches and one resin system as matrix precursors. The percentage of matrix in the composites was dependent on the surface area of the carbon cloth substrate. The oxidation behavior of the composites and their individual components was studied over the entire burn-off range (0-100%). The structure of the starting and partially reacted composites was investigated by X-ray diffraction, scanning electron microscopy and polarized-light optical microscopy. For the low-temperature composites, no synergism was found when thermoplastic matrices were used. When the thermosetting resin matrix was used, the oxidation behavior of the composites could not be predicted from that of their constituents. For the high-temperatures composites, synergistic effects were observed: composites obtained using high-surface-area activated carbon cloth showed improved oxidation resistance with respect to their individual components. In contrast, a simple additive effect was observed for the low-surface-area rayon-based composites.

关键词： OXIDATION CARBON CARBON COMPOSITES LIQUID-PHASE IMPREGNATION CARBONIZATION

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CARBONIZATION OF PETROLEUM FEEDSTOCKS .1. RELATIONSHIPS BETWEEN CHEMICAL CONSTITUTION OF THE FEEDSTOCKS AND MESOPHASE DEVELOPMENT

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CARBON 1989年第6期27卷 877-887页

作者： ESER, S JENKINS, RG Fuel Science Program Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 U.S.A.

The relationships between the chemical constitution of the petroleum feedstocks and the mesophase development were investigated. A range of coker feedstocks that were characterized by solvent fractionation, elemental analysis, and FT-IR were carbonized in conventional tubing bomb reactors. The solid carbonization products were examined by polarized-light microscopy. In general, a direct relationship was observed between the degree of aromaticity of the feedstocks and the extent of mesophase development. The separate carbonization of the asphaltene and maltene fractions of the feedstocks indicated that the asphaltenes dominated in determining the optical textures of the semicokes produced from the petroleum feedstocks.

关键词： Carbonization mesophase delayed coking petroleum feedstocks

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ON THE IMPORTANCE OF THE ELECTROKINETIC PROPERTIES OF CARBONS FOR THEIR USE AS CATALYST SUPPORTS

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CARBON 1990年第2-3期28卷 369-375页

作者： SOLAR, JM LEON Y LEON, CA OSSEOASARE, K RADOVIC, LR Fuel Science Program Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 U.S.A.

Equilibrium adsorption of molybdenum on different carbon supports resulted in widely varying catalyst uptakes. The results were rationalized on the basis of varying degrees of electrostatic interaction between the catalyst precursor and the supports. This interaction is known to be dependent on the surface charge of the support (which in turn depends on the pH of the catalyst precursor solution) and the charge of the ionic precursor. The carbon supports were subjected to widely varying thermal and chemical pretreatments. Their surface charge (electrokinetic mobility as a function of pH) was determined by electrophoresis. This study and a critical analysis of the literature illustrate the heretofore mostly neglected fact that, for achieving controlled catalyst uptake and/or a high degree of catalyst dispersion, it is not sufficient to create adsorption (or catalyst anchoring) sites on the carbon support surface; these must also be made accessible to the catalyst precursor. If the isoelectric point of the support is known, the precursor can be chosen and/or the solution pH can be modified to favor catalyst precursor/support interaction (e.g., adsorption), and thus maximize initial catalyst dispersion.

关键词： Carbon-supported catalysts adsorption electrokinetic properties surface charge

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The wide range of battery systems: From micro- to structural batteries, from biodegradable to high performance batteries

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Progress in materials science 2025年 154卷

作者： Costa, Carlos M. Salado, Manuel Ferrara, Chiara Ruffo, Riccardo Mustarelli, Piercarlo Mao, Rui Feng, Sheng Shang, Yuxiang Wang, Xiaochen Lei, Zhenkun Bai, Ruixiang Yan, Cheng Lee, Kwon-Hyung Kim, Sang-Woo Kim, Tae-Hee Lee, Sang-Young Kong, Long Zhang, Qiang Devnani, Harsha Gupta, Shikha Rohan, James F. Curtis, Neil S. Lahiri, Abhishek He, Yinghe Lanceros-Mendez, S. and Laboratory of Physics for Materials and Emergent Technologies LapMET University of Minho Braga4710-057 Portugal University of Minho Braga4710-053 Portugal BCMaterials Basque Center for Materials Applications and Nanostructures UPV/EHU Science Park Leioa48940 Spain IKERBASQUE Basque Foundation for Science Bilbao48009 Spain Department of Materials Science University of Milano-Bicocca and GISEL-INSTM Via Cozzi 55 Milano20125 Italy State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Dalian University of Technology Dalian116024 China School of Mechanical Medical and Process Engineering Queensland University of Technology BrisbaneQLD4001 Australia Ulsan44776 Korea Republic of Ulsan44919 Korea Republic of School of Chemical Engineering University of Ulsan Ulsan44610 Korea Republic of Department of Chemical and Biomolecular Engineering Yonsei University Seoul03772 Korea Republic of Institute of Flexible Electronics Northwestern Polytechnical University Xi'an710129 China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical Engineering Tsinghua University Beijing100084 China Department of Sciences School of Sciences Manav Rachna University Faridabad121004 India University Instrumentation Center Manav Rachna University Faridabad121004 India Department of Chemistry Faculty of Engineering and Technology Manav Rachna International Institute of Research & Studies Faridabad121004 India Tyndall National Institute Lee Maltings University College Cork CorkT12 R5CP Iceland Department of Chemical Engineering Brunel University of London UxbridgeUB8 3PH United Kingdom

Battery systems are essential components of the on-going energy transition and digitalization of society. With the need to power an increasing variety of portable and stationary systems, ranging from disposable point-of-care devices or smart packaging systems to applications in portable computers and electric cars, an increasing variety of batteries and battery systems are being developed, each aiming to specific sets of required performance parameters, including energy and power density, cycling stability, flexibility, degradability, environmental impact or improved integration into the specific application context. This work analyzed the state of the art of the different materials and geometries, performance parameters and applications of the different battery systems. We discuss the rationale behind each material selection, the processing technologies and the integration into the specific application, taking into account the whole life-cycle of the battery. Further, the main challenges posed for each battery type will provide a roadmap for their successful development and application. © 2025 The Author(s)

关键词： Automotive batteries

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