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Correlation of the Meishucunian Stage in South Asia

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Acta Geologica Sinica(English Edition) 1989年第1期63卷 1-9页

作者： M.d.brasier b.Hamdi department of Geology University of Hull Hull Hu6 7RX England. Geological Survey of Iran P. O. Box 1964. Teheran Iran.

The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sections in South Asia not only possess the conditions for selection of a boundary stratotype, but also provide the basis for the long-distance correlation of those boundary sections.Through a detailed study of the latest data obtained from the typical sections in South China, the Lesser Himalaya Mountains and the Alborz Mountains. the locations of boundary points have been defined, and a correlation scheme is proposed, which contributes to the solution of the problem of worldwide correlation of boundary sections.

关键词： Correlation of the Meishucunian Stage in South Asia

Advanced analytical determination of volatile organic compounds (VOC) and other major contaminants in water samples using GC-Ion Trap MS

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Journal of Environmental Sciences 2001年第1期13卷 25-36页

作者： Koroma, b. M. Wang, Kai-xiong Jinya, d. d. Laboratory of Socioeconomic Science of Food Production Nagoya University Japan department of Environmental Engineering Zhejiang University Hangzhou 310029 China. E-mail:[email protected] Kitakyushu Institute of Environmental Sciences Kitakyushu City Japan

The GC-Ion Trap MS is recently one of the most efficient instrumental analysis recommended for understanding the chemistry of these organic compounds, not only in water but even in the food chain and other environmental media (air and soil). Results of the experiment conducted on water samples from Kuguri and Yatsutani sampling stations showed considerably higher levels of organic enrichment (COd=10 mg/L and 11 mg/L respectively). Total concentrations of Pb (0.072 mg/L and 0.093 mg/L) and Cd (0.004 mg/Land 0.011 mg/L) on the other hand, invariably exceeded the maximum allowable concentrations for human health and the living environment (Pb=0.005 mg/L; Cd=0.001 mg/L respectively). And the toxicity levels for these contaminants at LC_50 showed critical impact on rainbow trout (hypersensitive species) at 0.14 mg/L for Pb and 0.007 mg/L for Cd in 96 hours respectively. Although these major contaminants including phenol and 3-, 4-cresol, showed relatively higher toxicity impact in the experimental media, it would remain contentious to justify any associated potential dangers without regular routine water monitoring, at least for a period of one year. Nevertheless, the data could serve as a benchmark through which other phenomena can easily be investigated.

关键词： www Advanced analytical determination of volatile organic compounds and other major contaminants in water samples using GC-Ion Trap MS VOC Eb GC

degradation of Synthetic dyeing Wastewater by Underwater Electrical discharge Processes

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Plasma Science and Technology 2013年第7期15卷 659-665页

作者： S.d.KIM d.I.JANG b.J.LIM S.b.LEE Y.S.MOK Yeongsan River Environment Research Center National Institute of Environmental ResearchGwangju 500-480 Korea department of Chemical and biological Engineering Jeju National UniversityJeju 690-756 Korea

Electrical discharge treatments of synthetic dyeing wastewater were carried out with two different systems： underwater pulsed electrical discharge （UPEd） and underwater dielectric barrier discharge （Udbd）. Reactive blue 4 （Rb4） and Acid Red 4 （AR4） were used as model contaminants for the synthetic wastewater. The performance of the aforementioned systems was compared with respect to the chromaticity removal and the energy requirement. The results showed that the present electrical discharge systems were very effective for degradation of the dyes. The dependences of the dye degradation rate on treatment time, initial dye concentration, electrical energy, and the type of working gas including air, 02, and N2 were examined. The change in the initial dye concentration did not largely affect the degradation of either Rb4 or AR4. The energy delivered to the UPEd system was only partially utilized for generating reactive species capable of degrading the dyes, leading to higher energy requirement than the Udbd system. Among the working gases, the best performance was observed with O2. As the degradation proceeded, the concentration of total dissolved solids and the solution conductivity kept increasing while pH showed a decreasing trend, revealing that the dyes were effectively mineralized.

关键词： degradation dyeing wastewater pulsed electrical discharge dielectric barrierdischarge

deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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Journal of Rare Earths 2004年第Z2期22卷 153-156页

作者： d H Jung b Park J J Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-b-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-b-N coatings were prepared by using a Tib2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. by applying ICP and a bias voltage to the substrate the hardness of the Ti-b-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-b-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

Analytical Solution of the blast Wave Problem in a Non-Ideal Gas

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Chinese Physics Letters 2011年第11期28卷 152-154页

作者： L.P.Singh S.d.Ram d.b.Singh department of Applied Mathematics Institute of TechnologyBanaras Hindu UniversityVaranasi-221005India

An analytical approach is used to construct the exact solution of the blast wave problem with generalized geometries in a non-ideal *** is assumed that the density ahead of the shock front varies according to a power of distance from the source of the blast ***,an analytical expression for the total energy in a non-ideal medium is derived.

关键词： wave analytical assumed

Effect of spark plasma sintering and reinforcements on the formation of ultra-fine and nanograins in AA2024-Tib2-Y hybrid composites

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Progress in Natural Science:Materials International 2022年第1期32卷 79-86页

作者： CH.Suresh Vidyasagar d.b.Karunakar department of Architecture and Planning Indian Institute of Technology Roorkee Mechanical and Industrial Engineering department Indian Institute of Technology Roorkee

This study reports the influence of sintering mechanism and reinforcement materials on the formation of ultra-fine and nanograins in Al-Tib-Y nanohybrid composites. The mechanical properties of the composites and their corresponding micro and nanostructures are correlated. The experimental and characterization results revealed that despite the addition of Tib, the hard and brittle AlTi phase formation in the composites was suppressed and hence, their ductility was retained. It was found that yttrium content of 0.3 wt% was the optimum amount which created advantageous spark plasma sintering conditions, and the addition of 0.3 wt% promoted the formation of bi-modal size grains（ultra-fine and nano） along with micro grains, Ω and other nano precipitates, resulting in a significant enhancement in the composite properties. The formation of ultra-fine and nanograins may be attributed to the combined effect of melting and rapid solidification at necking zones due to Joule’s heating and thermomechanical fatigue. Among all the sintered composites, the highest hardness（137 HV）, ultimate tensile strength（UTS）(496 MPa), yield strength（YS）(438 MPa) with 15.7% elongation were obtained in the sintered sample reinforced with 1.0 wt% Tiband 0.3 wt% yttrium.

关键词： Hybrid composites Ultra-fine grains Nano grains Spark plasma sintering Nano precipitates Microstructure

On Inherent Irreversibility in a Reactive Hydromagnetic Channel Flow

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Journal of Thermal Science 2010年第1期19卷 72-79页

作者： O.d.Makinde O.Anwar bég Faculty of Engineering Cape Peninsula University of TechnologyP.O.Box 1906Bellville 7535South Africa. Mechanical Engineering department Harmer BuildingSheffield Hallam UniversitySheffieldS1 1WB EnglandUK.

This study is devoted to investigate the inherent irreversibility and thermal stability in a reactive electrically conducting fluid flowing steadily through a channel with isothermal walls under the influence of a transversely imposed magnetic *** a perturbation method coupled with a special type of Hermite-Pade' approximation technique,the simplified governing non-linear equation is solved and the important properties of overall flow structure including velocity field,temperature field and thermal criticality conditions are derived which essentially expedite to obtain expressions for volumetric entropy generation numbers,irreversibility distribution ratio and the bejan number in the flow field.

关键词： Hydromagnetic channel flow Entropy analysis Thermal criticality Arrhenius kinetics Hermite-Pade approximants

developments in Processing of Functionally Gradient Metals and Metal–Ceramic Composites:A Review

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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 825-838页

作者： T.P.d.Rajan b.C.Pai Materials Science and Technology division CSIR-National Institute for Interdisciplinary Science and TechnologyIndustrial Estate PO

Functionally gradient/graded materials （FGMs）, an emerging new class of materials, are the outcome of the recent innovative concepts in materials technology. FGMs are in their early stages of evolution and expected to have a strong impact on the design and development of new components and structures with better performance. FGMs exhibit gradual transitions in the microstructure and/or the composition in a specific direction, the presence of which leads to variation in the functional performance within a part. The presence of gradual transitions in material composition in FGMs can reduce or eliminate the deleterious stress concentrations and result in a wide gradation of physical and/or chemical properties within the material. Functionally graded metal-ceramic composites are also getting the attention of the researchers. Among the fabrication routes for FGMs such as chemical vapour deposition, physical vapour deposition, the sol-gel technique, plasma spraying, molten metal infiltration, self propagating high temperature synthesis, spray forming, centrifugal casting, etc., the ones based on solidification route are preferred for FGMs because of their economics and capability to make large size products. The present paper discusses and compares various solidification processing tech- niques available for the fabrication of functionally gradient metals and metal-ceramic composites and lists their properties and possible applications. The other processing methods are briefly described.

关键词： Functionally gradient materials Solidification Aluminium Centrifugal casting Infiltration

Theoretical study of differential cross sections for the ionization of helium by fast proton impact

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Chinese Physics b 2024年第11期33卷 255-264页

作者： M Mondal b Mandal T Mistry d Jana M Purkait department of Physics Ramakrishna Mission Residential CollegeNarendrapurKolkata-700103India

We present the angular distribution of the ejected electron for single ionization of He by fast proton impact.A fourbody formalism of the three-Coulomb wave is applied to calculate the triple differential cross sections at several impact energies in the scattering,perpendicular and azimuthal ***,the three-body formalism of three-Coulomb,two-Coulomb and first born approximation models has also been used to study the many-body effect on electron emission and the validity of the *** the three-Coulomb wave model,the final state wave function incorporates distortion due to the three-body mutual Coulombic *** this formalism,we use an uncorrelated and correlated born initial state,which consists of a plane wave for the incoming projectile times a two-electron bound state wavefunction of the helium atom representing the 1s2(1S)***,in the case of the three-body formalism,the initial state wavefunction consists of a long-range Coulomb distortion for the incoming projectile and one active electron of the He atom described by the Roothaan–Hartree–Fock *** structure with a single or two peaks with unequal intensity is observed in the angular distributions of the triple differential cross sections for the different kinematic *** addition,the influence of static electron correlations is investigated using different bound state wavefunctions for the ground state of the He *** the four-body formalism,the present computations are very fast by reducing a nine-dimensional integral to a two-dimensional real *** the simplicity and speed of the proposed quadrature,the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other theories.

关键词： ionization cross sections collision atoms ions