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Organic carbon content and carbon isotope variations across the Permo-Triassic boundary in the gartnerkofel-1borehole, Carnic Alps, Austria

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Acta geochimica 2018年第3期37卷 422-432页

作者： M.E.Brookfield W.S.Wolbach A.g.Stebbins I.gilmour D.R.Roegge School for the Environment University of Massachusetts at Boston Department of Chemistry De Paul University Department of Physical Sciences Planetary and Space Sciences The Open University Department of Chemistry Illinois Wesleyan University

The gartnerkofel borehole is one of the most thoroughly studied and described Permo-Triassic sections in the world. Detailed bulk organic carbon isotope studies show a negative base shift from-24% to-28% in the Latest Permian which latter value persists into the Earliest Triassic after which it decreases slightly to-26%. Two strongly negative peaks of [-38% in the Latest Permian and a lesser peak of-31% in the Early Triassic are too negative to be due to a greater proportion of more negative organic matter and must be due to very negative methane effects. The overall change to more negative values across the Bulla/Tesero boundary fits the relative rise in sea level for this transition based on the facies changes. A positive shift in organic carbon isotope values at the Late Permian Event Horizon may be due to an increase in land-derived organic detritus at this level—a feature shown by allTethyan Permo-Triassic boundary sections though these other sections do not have the same values. Carbonate carbon isotope trends are similar in all sections dropping by2–3 units across the Permo-Triassic boundary. gartnerkofel carbonate oxygen values are surprisingly, considering the ubiquitous dolomitization, compatible with values elsewhere and indicate reasonable tropical temperatures of 60 °C in the Latest Permian sabkhas to 20–40 °C in the overlying marine transition beds. Increased landderived input at the Late Permian Event Horizon may be due to offshore transport by tsunamis whose deposits have been recognized in India at this level.

关键词： Organic Carbon Isotopes Permo-Triassic gartnerkofel Austria

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SIMULATION OF STEEL COIL HEAT TRANSFER IN HPH FURNACE

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Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 647-652页

作者： M. Y. gu g. Chen M. C. Zhang X. C. Dai School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200240 China School of Metallurgy and Material Anhui University of TechnologyMaanshan 243002 China Bao Shan Iron and Steel Corporation Ltd. Shanghai 201900 China

The mathematical model has been estublished for the simulation of steel coil＇s heat transfer during annealing thermal process in HPH （high performance hydrogen） furnace. The equivalent radial thermal conductivity is adopted by statistical analysis regression approach through the combination of a large quantity of production data collected in practice and theoretical analyses. The effect of the number of coils on circulating flow gas is considered for calculating the convection heat transfer coefficient, The temperature within the coil is predicted with the developed model during the annealing cycle including heating process and cooling process. The good consistently between the predicted results and the experimental data has demonstrated that the mathematical model established and the parameters identified by this paper are scientifically feasible and the effective method of calculation for coil equivalent radial heat transfer coefficient and circulating gas flow has been identified successfully, which largely enhances the operability and feasibility of the mathematic- model. This model provides a theoretical basis and an effective means to conduct studies on the impact that foresaid factors may imposed on the steel coil＇s temperature field, to analyze the stress within coils, to realize online control and optimal production and to increase facilily output by increasing heating and cooling rates of coils without producing higher thermal stress.

关键词： furnace equivalent radial thermal conductivity convection heat transfer coefficient simulation

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Does cypermethrin affect enzyme activity, respiration rate and walking behavior of the maize weevil （Sitophilus zeamais）？

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Insect Science 2013年第3期20卷 358-366页

作者： Ronnie Von Santos Veloso Eliseu Jose g. Pereira Raul Narciso C. guedes Maria goreti A. Oliveira Departamento de Entomologia Departamento de Bioquimica e Biologia Molecular Universidade Federal de Vicosa Brazil

Insecticides cause a range of sub-lethal effects on targeted insects, which are frequently detrimental to them. However, targeted insects are able to cope with insecti- cides within sub-lethal ranges, which vary with their susceptibility. Here we assessed the response of three strains of the maize weevil Sitophilus zeamais Motschulsky （Coleoptera.＂ Curculionidae） to sub-lethal exposure to the pyrethoid insecticide cypermethrin. We ex- pected enzyme induction associated with cypermethrin resistance since it would aid the resistant insects in surviving such exposure. Lower respiration rate and lower activity were also expected in insecticide-resistant insects since these traits are also likely to favor survivorship under insecticide exposure. Curiously though, cypermethrin did not affect ac- tivity of digestive and energy metabolism enzymes, and even reduced the activity of some enzymes （particularly for cellulase and cysteine-proteinase activity in this case）. There was strain variation in response, which may be （partially） related to insecticide resistance in some strains. Sub-lethal exposure to cypermethrin depressed proteolytic and mainly cellulolytic activity in the exposed insects, which is likely to impair their fitness. However, such exposure did not affect respiration rate and walking behavior of the insects （except for the susceptible strain where walking activity was reduced）. Walking activity varies with strain and may minimize insecticide exposure, which should be a concern, particularly if associated with （physiological） insecticide resistance.

关键词： insecticides insecticide resistance pyrethroids stored grain insect sub-lethal effects

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Optical and electrical properties and phonon drag effect in low temperature TEP measurements of AgSbSe_2 thin films

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Journal of Semiconductors 2014年第5期35卷 1-6页

作者： T Namitha Asokan K S Urmila Rajani Jacob Rachel Reena Philip g S Okram V ganesan B Pradeep Solid State Physics Laboratory Department of Physics Cochin University of Science and Technology Thin Film Research Lab Department of Physics Union Christian College UgC-DAE Consortium for Scientific Research

Polycrystalline thin films of silver antimony selenide have been deposited using a reactive evaporation technique onto an ultrasonically cleaned glass substrate at a vacuum of 10-5 torr. The preparative parameters, like substrate temperature and incident fluxes, have been properly controlled in order to get stoichiometric, good quality and reproducible thin film samples. The samples are characterized by XRD, SEM, AFM and a UV-vis-NIR spectrophotometer. The prepared sample is found to be polycrystalline in nature. From the XRD pattern, the average particle size and lattice constant are calculated. The dislocation density, strain and number of crystallites per unit area are evaluated using the average particle size. The dependence of the electrical conductivity on the temperature has also been studied and the prepared AgSbSe2 samples are semiconducting in nature. The AgSbSe2 thin films exhibited an indirect allowed optical transition with a band gap of 0.64 eV. The compound exhibits promising thermoelectric properties, a large Seebeck coefficient of 30 mV/K at 48 K due to strong phonon electron interaction. It shows a strong temperature dependence on thermoelectric properties, including the inversion of a dominant carrier type from p to n over a low temperature range 9-300 K, which is explained on the basis of a phonon drag effect.

关键词： silver antimony selenide reactive evaporation thermoelectric power phonon drag effect

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Chemical Properties and Biochemical Activity of Colonized and Abandoned Litter-Feeding Termite(Macrotermes spp.) Mounds in Chromic Cambisol Area on the Borana Plateau, Ethiopia

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Pedosphere 2014年第3期24卷 399-407页

作者： L.MENICHETTI L.LANDI P.NANNIPIERI T.KATTERER H.KIRCHMANN g.RENELLA Department of Soil and Environment Swedish University of Agricultural Sciences Department Agrifood Production and Environmental Sciences University of Florence

Termite （Macrotermes spp.） mounds are complex biological habitats originated by the termite activity and possessing peculiar physical, chemical and biochemical properties. In this study we examined the concentration of nutrients and the biochemical activity of abandoned soil and mounds colonized by termites of the genera Macroterrnes located in the Borana District, Ethiopia. To elucidate the magnitude and persistence of the termite-induced effects, we also studied an abandoned mound, previously colonized by termites of the same genera formed on the same soil. Results confirmed that termite-colonized mounds are ＇hot spots＇ of nutrient concentration and microbial activity in tropical soils. This is due to the termite driven litter input and decomposition. The abandoned mounds showed higher microbial biomass and activity and displayed a nutrient redistribution and a greater microbial activity than the adjacent soils. These findings allowed us to hypothesize a model of nutrient cycling in colonized soils and a partition of the relative roles of termites and soil microorganisms in nutrient location and turnover in tropical soils. These results may be also useful for the optimal management of termite-colonized soils.

关键词： enzyme activity microbial activity microbial biomass nutrient cycling nutrient turnover

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Autophagic flux response and glioblastoma sensitivity to radiation

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Cancer Biology & Medicine 2018年第3期15卷 260-274页

作者： Achilleas g.Mitrakas Dimitra Kalamida Alexandra giatromanolaki Stamatia Pouliliou Avgi Tsolou Rafail Kyranas Michael I.Koukourakis Department of Radiotherapy/Oncology democritus university of thraceand university general hospital of alexandroupolisAlexandroupolis 68200Greece Department of Pathology Democritus University of Thraceand University General Hospital of AlexandroupolisAlexandroupolis 68200Greece

Objective:glioblastoma is the most common primary brain tumor in adults and one of the most lethal human *** constitutes a unique non-metastasizing human tumor model with high resistance to radiotherapy and *** current study investigates the association between autophagic flux and glioblastoma cell ***:The expression kinetics of autophagy-and lysosome-related proteins following exposure of two glioblastoma cell lines(T98 and U87)to clinically relevant radiation doses was ***,the response of cells resistant to radiotherapy and chemotherapy was investigated after silencing of LC3A,LC3B,and TFEB genes in vitro and in ***:Following irradiation with 4 gy,the relatively radioresistant T98 cells exhibited enhanced autophagic *** more radiosensitive U87 cell line suffered a blockage of autophagic *** of LC3A,LC3B,and TFEB genes in vitro,significantly sensitized cells to radiotherapy and temozolomide(U87:Pg of the LC3A gene sensitized mouse xenografts to ***:Autophagy in cancer cells may be a key factor of radio-resistance and chemo-resistance in glioblastoma *** autophagy may improve the efficacy of radiochemotherapy for glioblastoma patients.

关键词： glioblastoma autophagy radiation temozolomide TFEB

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Asphaltene aggregation studied by molecular dynamics simulations:role of the molecular architecture and solvents on the supramolecular or colloidal behavior

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Petroleum Science 2019年第3期16卷 669-684页

作者： H.Santos Silva A.Alfarra g.Vallverdu D. Begue B.Bouyssiere I.Baraille Institut des Science Analytiques et Physico-Chimie pour l'Environnement et les Materiaux UMR 5254 CNRS/Univ Pau and Pays Adour 64000 Pau France Total Research and Technology BP 2776700 Gonfreville Harfleur France Joint Laboratory C2MC: Complex Matrices Molecular Characterization Total Research and Technology BP 2776700 Gonfreville Harfleur France

Asphaltene aggregation is a subject under vivid discussion:There are several parameters one needs to determine before its behavior can be mastered and better target solutions can be *** nature of asphaltene aggregation(colloidal or supramolecular)and the role of solvents and their mixtures are among the least understood parameters in asphaltene *** paper addresses molecular dynamic simulations to correlate the aggregation properties of asphaltenes,their molecular structure and the concentration of these *** show that the formation of the nanoaggregate depends,primarily,on the size of the conjugated core and on the eventual presence of polar groups capable of forming *** on the conjugated core do not change their shape or type of aggregation but may induce stronger π-π *** macroaggregation formation depends upon the length of the lateral chains of asphaltenes and also on the presence of polar groups at its ***,n-heptane and water may interact selectively with asphaltenes in function of their molecular *** this fact and the aggregation behavior observed,we advocate toward the assumption that a colloidal behavior of asphaltenes might be a particular case of a more general model,based on a supramolecular description.

关键词： Asphaltenes Molecular dynamics Aggregation Heavy oil

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Optimal and synchronized germination of Robinia pseudoacacia,Acacia dealbata and other woody Fabaceae using a handheld rotary tool:concomitant reduction of physical and physiological seed dormancy

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Journal of Forestry Research 2018年第2期29卷 283-290页

作者： Nuria Pedrol Carolina g.Puig Antonio Lo′pez-Nogueira Maria Pardo-Muras Luis gonzalez Pablo Souza-Alonso Department of Plant Biology and Soil Science Faculty of BiologyUniversity of VigoUniversity Campus36310 VigoSpain

The Fabaceae(legume family) is one of the largest families of plants with a worldwide distribution and a major role in agriculture and in agroforestry.A hard seed coat impermeable to water is a typical feature of several *** dormancy delays and reduces germination so that mechanical,physical and chemical scarification methods have been classically used to break seed dormancy of many *** evaluate the effectiveness of a methodology to scarify seeds of several woody Fabaceae of ecological and economical importance,including Robinia pseudoacacia and Acacia dealbata and the shrubs Cytisus scoparius,*** and Ulex *** describe the optimized use of a handheld rotary tool(HRT),and compare its effectiveness with other scarification methods reported to break dormancy such as boiling or dry *** germination and/or speed of germination were enhanced after the application of the HRT,with germination percentages significantly higher than those achieved by other methods of *** on a thorough literature review,a mode of action for the HRT is suggested which could operate by breaking the physical and physiological dormancy of treated seeds through thecombined action of coat abrasion and moderate *** these results,we recommend the application of this rapid,effective,low-cost and highly reproducible HRT method to break seed dormancy and enhance germination of these species and others with similar dormancy constraints.

关键词： Combinational dormancy Hardcoat Rotary tool Scarification Temperature

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Potential emission reductions by converting agricultural residue biomass to synthetic fuels for vehicles and domestic cooking in China

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Particuology 2020年第2期18卷 40-47页

作者： Xiaoliang Wang SKent Hoekman Yang Han Judith CChow John g.Watson Xiaomeng Wu Ye Wu Dennis Schuetzle Robert Schuetzle Desert Research Institute 2215 Raggio PkwyRenoNV 89512USA School of Environment Tsinghua UniversityBeijing 100084China greyrock Energy Inc.2020 L StreetSuite 120SacramentoCA 95811USA

Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural *** agricultural waste-generated synthetic fuels can reduce emissions both from vehicles and biomass *** estimate the potential benefits of synthetic diesel in Beijing,the emission factor model for the Beijing vehicle fleet was applied to estimate exhaust emissions for the 2015-2030 *** with 100%petroleum diesel,a 20%synthetic diesel blend reduced diesel fleet emissions by 24%for carbon monoxide,30%for total hydrocarbons,5.5%for nitrogen oxides,and 19%for fine particulate matter with an aerodynamic diameter of≤2.5μm(PM2.5)while using 100%synthetic diesel decreased emissions by 36%for carbon monoxide,48%for total hydrocarbons,10%for nitrogen oxides,and 34%for *** use of biomass for producing synthetic fuels rather than burning in the field also reduces air *** 60g of PM2.5 agricultural open-field burning emissions are avoided per liter of synthetic fuel *** solid crop residues with synthetic liquid fuels in household cooking would reduce PM2.5 emissions by more than 90%.

关键词： PM2.5 Air pollution Vehicle emission Biomass burning Synthetic fuel Agricultural biomass

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Mechanical and thermal properties of AA7075/TiO2/Fly ash hybrid composites obtained by hot forging

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Progress in Natural Science:Materials International 2017年第4期27卷 474-481页

作者： K.V.Shivananda Murthy D.P.girish R.Keshavamurthy Temel Varol Praveennath g.Koppad Department of Mechanical Engineering Government Engineering Colleg 2. Department of Mechanical Engineering Dayananda Sagar College of Engineering 3. Department of Metallurgical and Materials Engineering Karadeniz Technical University 4. Department of Mechanical Engineering CMR Institute of Technology

In the present paper, multiple reinforcements TiO2 and fly ash were utilized for the fabrication of AA7075 matrix based hybrid composites using stir casting technique followed by hot forging. In hybrid composites, the fly ash content was fixed to 3 wt% while that of TiO2 was varied from 2.5 to 10 wt%. Scanning electron microscopy images revealed homogenous dispersion of both the reinforcements in AA7075 *** test was conducted to study the mechanical behaviour of hybrid composites. The hybrid composites showed increase in compressive strength with the incorporation of multiple reinforcements and further increased with the increase in the weight fractions of TiO2 particles. The coefficient of thermal expansion was measured between 50 and 250 ℃ with a high precision thermal mechanical analyser. The thermal coefficient of hybrid composites decreased with the addition of TiO2 and fly ash. However a slight decrease in thermal conductivity of hybrid composites was observed when compared to that of AA7075 alloy.

关键词： Hybrid composites Hot forging Mechanical properties Thermal properties

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