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Understanding the paleomires of Eocene lignites of k.chchh Basin, Gujarat （Western India）： petrological implications

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International Journal of Coal Science & Technology 2017年第2期4卷 80-101页

作者： Prak.sh k. Singh Vijay k. Singh M. P. Singh P. k. Rajak Coal and Organic Petrology Lab Centre of Advanced Studyin Geology Banaras Hindu University VaranasiUttar Pradesh 221005 India

The present paper entails the results of the investigations carried out on the lignite deposits of k.chchh Basin. The lignite samples were drawn from five lignite seams from Panandhro lignite field （Seam-I to -V） and eight lignite seams （Seam-I to -VIII） from the Matanomadh lignite field which are currently operational. The petrographic analysis of the lignites indicates a dominance of huminite group of macerals which is mainly contributed by ulminite-A, ulminite-B, attrinite, densinite, and phlobaphinite. Liptinite （chiefly sporinite, cutinite, resinite, and liptodetrinite） and inertinite （chiefly fusinite, funginite, and inertodetrinite） groups occur in subordinated amount. The mineral matter occurs in moderate concentration. Though sulfur content is high in these lignites, there is no fixed trend of variation of sulfur from bottom seam to top seam. The investigation reveals a flooded forest swamp having high rate of degradation. However, there were a few drier periods indicated by relatively more inertinite macerals. The petrography-based models indicate that the k.chchh lignites of Gujarat evolved in coastal marshy setting under transgressive phase. However, there were few intermittent fluvial activities giving rise to supratidal flood plain. This led to the formation of the associated carbonaceous shales in the basin.

关键词： k.chchh Basin Eocene lignite Petrography Paleomire

An Analysis of the Invariance and Conservation Laws of Some Classes of Nonlinear Ostrovsk. Equations and Related Systems

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Chinese Physics Letters 2011年第1期28卷 1-4页

作者： k. Fak.ar A. H. k.ra Department of Mathematics Faculty of Science Universiti Teknologi Malaysia 81310 UTM Skudai Johor Malaysia School of Mathematics and Centre for Differential Equations Continuum Mechanics and Applications University of the Witwatersrand Johannesburg P Bag 3 Wits 2050 South Africa

A large class of partial differential equations in the modelling of ocean waves are due to Ostrovsk.. We determine the invariance properties （through the Lie point symmetry generators） and construct classes of conservation laws for some of the models. In the latter case, the method involves finding the ＇multipliers＇ associated with the conservation laws with a stronger emphasis on the ＇higher-order＇ ones. The relationship between the symmetries and conservation laws is investigated by considering the invariance properties of the multipliers.

关键词： Mathematical physics Statistical physics and nonlinear systems

Petrographic characteristics and paleoenvironmental history of Eocene lignites of Cambay basin, Western India

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International Journal of Coal Science & Technology 2017年第3期4卷 214-233页

作者： Prak.sh k. Singh Vijay k. Singh M. P. Singh P. k. Rajak Coal and Organic Petrology Lab Centre of Advanced Study in Geology Banaras Hindu University Varanasi Uttar Pradesh 221005 India

Lignite samples collected from Vastan, Rajpardi and Tadk.shwar lignite mines of Cambay basin （Gujarat） were subjected to organic petrographic investigations and geochemical analyses and the data, thus generated, is used to reconstruct the paleodepositional history of these lignite sequences. The lignites of Cambay basin dominantly comprise huminite maceral group （71.6%-86.3%） followed by liptinite （10.1%-19.3%） and inertinite （3.6%-11.0%） maceral groups. The mineral matter varies from 9.0% to 20.0%. The petrography based facies model indicates that these lignites have high values of gelification index （GI） and low tissue preservation index revealing a continuous wet condition in the basin and a relatively slower rate of subsidence during the decay of organic matter. On several occasions, during the formation of seams in Tadk.shwar, Rajpardi and Vastan mines, the value of GI exceeded 10 which indicates a forest permanently flooded and the cause of pronounced degree of degradation. However, few sections in Tadk.shwar seam had relatively drier spells of environmental conditions due to fluctuation in the water table as revealed by moderately high content of inertinite macerals. This is specially indicated by the occurrence of funginite which normally thrives in the upper oxy- genated peatigenic layer and indicates prevalence of oxic conditions during plant deposition. Such conditions prevailed during a transgressive phase but there were intermittent fluvial activities also giving rise to supratidal flood plain as reflected in the form of associated carbonaceous shales in the basin.

关键词： Cambay basin Western India Lignite Maceral Paleodepositional environment

Post-failure behavior of tunnel heading collapse by MPM simulation

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Science China(Technological Sciences) 2015年第12期58卷 2139-2152页

作者： CHENG XueSong ZHENG Gang SOGA k. BANDARA S.S. k.MAR k. DIAO Yu XU Jie MOE k.y Laboratory of Coast Civil Structure Safety Tianjin University Department of Civil Engineering Tianjin University Department of Engineering University of Cambridge

Tunnel collapse presents a serious threat to the safety of urban construction. The traditional approach adopted to assess this risk.is to evaluate the factor of safety against failure. However, this analysis only determines on whether the tunnel will collapse or not, and does not provide information on the magnitude of the post-failure behavior(for example, catastrophic or progressive) if the tunnel collapse occurs. In this study, a meshless method based on the material point method(MPM) was used to investigate the post-failure behavior of tunnel heading collapse in two-dimensional plane-strain conditions. The capability and accuracy of MPM were verified by comparing the elicited results to centrifuge test data and to analytical solutions obtained from limit state methods. MPM simulations were conducted at different soil conditions(clay or sand) and profiles(homogenous or linear increasing strength) as well as at different tunnel geometries(i.e. tunnel depth and unlined length). The differences in the post-failure behavior and mechanisms are examined and reported.

关键词： tunnel stability collapse mechanism material point method large deformation

Effect of Discharge Voltage on an Ion Sheath Formed at a Grid in a Multi-Dipole Discharge Plasma

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Chinese Physics Letters 2008年第3期25卷 1011-1014页

作者： M. k. Mishra A. Phuk.n Centre of Plasma Physics.Tepesia Kamrup-782402 Assam INDIA

It is experimentally demonstrated that a relatively strong ion-rich sheath formed at a fixed negative bias of the grid can be changed to a rather weak.ion sheath （sheath potential weak.y retards electrons） only by increasing the discharge voltage in the system. At sufficiently high negative grid bias, an increase of discharge voltage enhances the ion collection current at the grid. An explanation is put forward in support of this experimental observation. A slight density enhancement with a fall in plasma electron temperature is also observed with the increasing negative grid bias.

关键词： supernova explosion proto-neutron star shock.wave

GENERALIZED INVEXITY-TYPE CONDITIONS IN CONSTRAINED OPTIMIZATION

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Journal of Systems Science & Complexity 2011年第2期24卷 394-400页

作者： Shashi k. MISHRA Norma G. RUEDA Department of Mathematics Faculty of Science Banaras Hindu University Varanasi 221005 India.Norma G. RUEDA Department of Mathematics Merrimack College North Andover MA 01845 USA.

This paper defines a new class of generalized type I functions, and obtains k.hn-Tuck.r necessary and sumcient conditions and duality results for constrained optimization problems in the presence of the aforesaid weak...

关键词： Constrained optimization duality results type I functions.

Seismic isolation effect of lined circular tunnels with damping treatments

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Earthquak. Engineering and Engineering Vibration 2008年第3期7卷 305-319页

作者： Seyyed M. Hasheminejad Amir k. Miri Acoustics Research Laboratory Department of Mechanical Engineering Iran University of Science and Technology Narmak Tehran 16844 Iran

The Havriliak.Negami model for dynamic viscoelastic material behavior and Biot＇s theory of poroelasticity are employed to develop an exact solution for three-dimensional scattering effect of harmonic plane P-SV waves from a circular cavity lined with a multilayered fluid-filled shell of infinite length containing viscoelastic damping materials and embedded within a fluid-saturated permeable surrounding soil medium. The analytical results are illustrated with numerical examples where the effects of liner/coating structural arrangement, viscoelastic material properties, liner-soil interface bonding condition, seismic excitation frequency, and angle of incidence on the induced dynamic stress concentrations are evaluated and discussed to obtain representative values of the parameters that characterize the system. It is demonstrated that incorporating viscoelastic damping materials with a low shear modulus in the constrained layer configuration is an efficient means of enhancing the overall seismic isolation performance, especially for near-normally incident seismic shear waves where the amplitudes of induced dynamic stresses may be reduced by up to one-third of those without isolation in a relatively wide frequency range. Some additional cases are considered and good agreements with solutions available in the literature are obtained.

关键词： underground tunnel permeable soil seismic wave scattering flee/constrained layer damping

Bound states of the Dirac equation with position-dependent mass for the Eck.rt potential

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Chinese Physics B 2013年第1期22卷 62-67页

作者： Bahar M. k. Yasuk.F. Department of Physics Erciyes University Department of Physics Karamanoglu Mehmetbey University

Studying with the asymptotic iteration method, we present approximate solutions of the Dirac equation for the Eck.rt potential in the case of position-dependent mass. The centrifugal term is approximated by an exponen... 详细信息

关键词： Dirac equation position-dependent mass Eck.rt potential asymptotic iteration method

Mesoporous carbon adsorbents from melamine–formaldehyde resin using nanocasting technique for CO_2 adsorption

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Journal of Environmental Sciences 2015年第6期27卷 238-248页

作者： Chitrak.hi Goel Haripada Bhunia Pramod k. Bajpai Department of Chemical Engineering Thapar University

Mesoporous carbon adsorbents, having high nitrogen content, were synthesized via nanocasting technique with melamine-formaldehyde resin as precursor and mesoporous silica as template. A series of adsorbents were prepared by varying the carbonization temperature from 400 to 700°C. Adsorbents were characterized thoroughly by nitrogen sorption, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, thermogravimetric analysis（TGA）, elemental（CHN） analysis, Fourier transform infrared（FTIR） spectroscopy and Boehm titration. Carbonization temperature controlled the properties of the synthesized adsorbents ranging from surface area to their nitrogen content, which play major role in their application as adsorbents for CO2 *** nanostructure of these materials was confirmed by XRD and TEM. Their nitrogen content decreased with an increase in carbonization temperature while other properties lik. surface area, pore volume, thermal stability and surface basicity increased with the carbonization temperature. These materials were evaluated for CO2 adsorption by fixed-bed column adsorption experiments. Adsorbent synthesized at 700°C was found to have the highest surface area and surface basicity along with maximum CO2 adsorption capacity among the synthesized adsorbents. Break.hrough time and CO2 equilibrium adsorption capacity were investigated from the break.hrough curves and were found to decrease with increase in adsorption temperature. Adsorption process for carbon adsorbent-CO2 system was found to be reversible with stable adsorption capacity over four consecutive adsorption-desorption cycles. From three isotherm models used to analyze the equilibrium data, Temk.n isotherm model presented a nearly perfect fit implying the heterogeneous adsorbent surface.

关键词： Carbon Nanocasting Mesoporous CO2 adsorption Isotherm