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MCsCF AND VTsT sTUDIEs OF THE REACTION CH(2~π)+H_2→CH_3

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Chinese Chemical Letters 1996年第5期7卷 471-474页

作者： Ma s.Y. Liu R.Z. Department of Chemistry Beijing Normal University Beijing 100875

Abstract: The reaction path of the reaction CH(2π)-H2→CH3 is traced with IRC theory and MCsCF 6-31G method. On this basis. the dynamical properties and VTsT rate constants are investigated. The results show that the... 详细信息

关键词： CH3 REACTION THE MCsCF OF sTUDIEs H2 AND

Distribution and ecology of lesser pouched rat,Beamys hindei,in Tanzanian coastal forests

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Integrative Zoology 2015年第6期10卷 531-542页

作者： Christopher A.sABUNI Vincent sLUYDTs Loth s.MULUNGU samwel L.s.MAGANGA Rhodes H.MAKUNDI Herwig LEIRs Pest Management Centre Sokoine University of AgricultureMorogoroTanzania Unit of Medical Entomology Institute of Tropical MedicineAntwerpBelgium Department of Wildlife Management Sokoine University of AgricultureMorogoroTanzania Evolutionary Ecology Group University of AntwerpAntwerpBelgium

The lesser pouched rat,Beamys hindei,is a small rodent that is patchily distributed in the Eastern Arc Mountains and coastal forests in East *** ecology of this species and its current distribution in coastal forests is not well ***,we conducted a study in selected coastal forests to assess the current distribution of the species and to investigate the population ecology in terms of abundance fluctuations and demographic *** of the species distribution were conducted in 5 forests through trapping with sherman live *** on ecology were obtained from monthly capture–mark–recapture studies conducted for 5 consecutive nights per month in two 1 ha grids set in Zaraninge Forest over a 2-year *** results indicate the presence of *** in 3 forests where it was not previously *** population abundance estimates ranged from 1 to 40 animals per month,with high numbers recorded during rainy *** patterns and sex ratios did not differ between *** estimates were not influenced by season,and recruitment was low,with growth rate estimates of 1 animal per *** estimates suggest a stable population of *** in Zaraninge *** studies are recommended to establish the home range,diet and burrowing behavior of the species in coastal forests in East Africa.

关键词： abundance Beamys hindei coastal forests recruitment survival

Effect of Wetting-Drying Cycles on Redistribution of Lead in some semi-Arid Zone soils spiked with a Lead salt

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Pedosphere 2012年第3期22卷 304-313页

作者： H.KHODAVERDILOO M.RAHMANIAN s.REZAPOUR s.GHORBANI DAsHTAKI H.HADI F.X.HAN Department of soil science Urmia UniversityUrmia 57135-165 (Iran) Department of soil science Shahrekord UniversityShahrekord 88186/34141 (Iran) Department of Agronomy and Plant Breeding Urmia UniversityUrmia 57135-165 (Iran) Department of Chemistry and Biochemistry JacksonState UniversityJacksonMS 39217-0510 (USA)

Mobility and bioavailability of lead （Pb） could be affected considerably by soil physicochemical properties; however, less is known about the effect of Pb levels and aging time. This study was conducted to evaluate the effects of Pb levels and wetting-drying （WD） cycles on distribution and bioavailability of Pb in three semi-arid zone soils treated with different levels of Pb（NO3）2. Wetting-drying cycles simulated the actual field irrigation in the semi-arid soils. A soil with a long history of Pb contamination was also taken as a reference soil. The soils were spiked with various levels of Pb and incubated under WD cycles for 160 d. sequential extractions and batch sorption experiments were performed to assess the fractionation of Pb in the spiked soils. Redistribution index （Uts） and reduced partitioning parameter （IR） were applied to semi-quantify the distribution of Pb in the spiked soils. A small amount of Pb sorbed was desorbed by the soils, indicating a strong and irreversible binding of Pb in the studied soils. Contribution of carbonate-bound （Car） and residual （Res） Pb fl＇actions to the total Pb of the soils was more than 97%. The Car, soluble plus exchangeable （sE）, and organic matter-bound （OMB） fractions of Pb were transferred to the Res fraction under the WD cycles. The IR and Uts values were influenced by Pb loading levels and WD; therefore, the Pb lability and/or redistribution pattern could semi-quantitatively be assessed via these parameters. At the end of the experiment, the Ia and Uts values for the Pb salt-spiked soils did not show the quasi- equilibrium state. The lability of Pb in the soils decreased with increasing incubation time and showed a strong dependence on Pb levels and soil chemical composition. WD cycles significantly affected the overall lability of Pb in soils through influencing the redistribution of Pb among solid-phase components.

关键词： bioavailability heavy metals mobility redistribution index reduced partitioning parameter

Gamma-ray and neutron shielding efficiency of Pb-free gadolinium-based glasses

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Nuclear science and Techniques 2016年第4期27卷 206-213页

作者： V.P.singh N.M.Badiger s.Kothan s.Kaewjaeng T.Korkut H.J.Kim J.Kaewkhao Department of Physics Karnatak University Department of Radiologic Technology Faculty of Associated Medical SciencesChiang Mai University Department of Nuclear Energy Engineering Faculty of Engineering Sinop University Department of Physics Kyungpook National University Center of Excellence in Glass Technology and Materials science Nakhon Pathom Rajabhat University

The radiation shielding efficiency of material depends upon photon attenuation, exposure buildup factors and neutron removal capacity. A newly developed Pb-free gadolinium-based glasses in compositions(80-x) B_2O_3-10 si O_2-10 Ca O-x Gd_2O_3(where x = 15, 20, 25, 30 and35 mol%) had completely been investigated for their shielding efficiency with Geant4 simulation for mass attenuation coefficients and neutron total macroscopic cross section and by calculating exposure buildup *** exposure buildup factors for photon energy from 0.015 to 15 Me V had been calculated up to 40 mean free paths using five factors geometric progression method. The mass attenuation coefficients of the Pb-free glasses were simulated for energies from 223 to 2614 ke V and compared with the possible available experimental results. The neutron shielding efficiency of these glasses was discussed by calculating neutron total macroscopic cross section for energies from 1 e V to 14.1 Me V. Present investigations are found to be very useful for applications in nuclear engineering.

关键词：无铅玻璃屏蔽效率中子质量衰减系数 γ射线光子能量截面计算 Geant4

A Combined Heterotic string and Kähler Manifold Elucidation of Ordinary Energy,Dark Matter,Olbers’s Paradox and Pure Dark Energy Density of the Cosmos

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Journal of Modern Physics 2017年第7期8卷 1101-1118页

作者： Mohamed s.El Naschie Department of Physics Faculty of ScienceUniversity of AlexandriaAlexandriaEgypt

We utilize the topological-geometrical structure imposed by the Heterotic superstring theory on spacetime in conjunction with the K3 Kähler manifold to explain the mysterious nature of dark matter and its coupling to the pure dark energy density of the cosmos. The analogous situations in the case of a Kerr black hole as well as the redundant components of the Riemannian tensor are pointed out and the final result was found to be in complete agreement with all previous theoretical ones as well as all recent accurate measurements and cosmic observations. We conclude by commenting briefly on the Cantorian model of Zitterbewegung and the connection between Olbers’s paradox and dark energy.

关键词： Heterotic strings K3 Kahler Manifold Dark Matter Pure Heterotic Dark Energy Einstein’s Relativity Accelerated Cosmic Expansion Negative Gravity Fractal spacetime E-Infinity Theory Kerr Black Holes Geometry Kaluza-Klein Theory Dvoretzky’s Theorem Empty set Zero set Connes Noncommutative Geometry ‘tHooft Renormalon sTATE Vector Reduction Density Matrix ‘tHooft Fractal spacetime Transfinite Cellular Automata Interpretation of Quantum Mechanics Zitterbewegung Olbers’s Dark sky Paradox

safety and success of precut biliary sphincterotomy: Is it linked to experience or expertise?

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World Journal of Gastroenterology 2007年第15期13卷 2183-2186页

作者： Lindsay s Robison shyam Varadarajulu C Mel Wilcox Division of Gastroenterology and Hepatology Pancreaticobiliary Center University of Alabama at BirminghamBirminghamAlabama

AIM： To determine the rates of success and complications of precut biliary sphincterotomy （PBs） based on prior experience and to compare the complication rates between PBs and standard endoscopic sphincterotomy （Es）. METHODs： A retrospective evaluation of prospectively collected non-randomized data at an academic tertiary referral center, The study included all patients in an eight-year period who underwent PBs and Es by a single endoscopist who had no formal training in PBs. The main outcorne measures of the study were success and complications of PBs with a comparison to complications of Es.REsULTs： A total of 2939 endoscopic retrograde chola ngiopancreatographies （ERCPs） were performed during the study period, including 818 （28%） Es and 150 （5%） PBs procedures. selective biliary cannulation via PBs was successful at the first attempt in 75% of the patients. Cannulation was achieved in an additional 13% of the patients at a subsequent attempt （total 87%）. Complication rate from PBs was 45% higher than Es, but did not differ significantly [7% （10/50） vs 5% （38/818）, P = 0.29]. None of the complications from PBs was severe. A significant trend towards increasing success existed with regard to the endoscopist＇s first attempt at precut （P = 0.0393, Cochran-Armitage exact test for trend, Z = -1.7588）. CONCLUsION： Despite the lack of specific training in this technique, PBs was performed with a high success rate and a complication rate similar to or less than reports from other experienced centers. These results suggest that endoscopic experience and perhaps innate endoscopic skill may play an important role in the outcome of this procedure.

关键词： Biliary sphincterotomy Precut sphincterotomy Complication rate Endoscopic skill

Transition Metal silicide Nanowires Growth and Electrical Characterization

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Chinese Physics Letters 2009年第12期26卷 206-209页

作者：彭祖林 LIANG s. 邓罗根 school of science Beijing Institute of Technology Beijing 100081 science and Engineering of Materials Program Arizona State University Tempe AZ 85287 USA

We report the characterization of self-assembled epitaxially grown transition metal, Fe, Co, Ni, silicide nanowires （TM-NW） growth and electrical transport properties. NWs grown by reactive deposition epitaxy on various silicon surfaces show a dimension of 10nm by 5nm, and several micrometers in length. NW orientations strongly depend on substrate crystal orientation, and follow the substrate symmetry. By using conductive-AFM （c-AFM）, the electron transport properties of one single NW were measured, the resistivity of crystalline nickel silicide NW was estimated to be 2×10-2Ω＆#12539;cm.

关键词： surfaces interfaces and thin films Nanoscale science and low-D systems

Preparation and surface Layer Modification of silicon Nanoparticles Dispersed in 2-Propanol

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Chinese Physics Letters 1998年第12期15卷 928-930页

作者： ZHU Yong s.Iwasaki K.Kimura ZHANG Li-de Institute of solid state Physics Chinese Academy of SciencesHefei 230031 Department of Material science Himeji Institute of TechnologyScience Garden CityKamigohriHyogo 678-12Japan

silicon nanoparticles dispersed in 2-propanol were prepared by using an arc plasma with gas flow method in a new designed home-made *** particles are composed of silicon crystal core covered by oxidized amorphous silicon *** composition of the particle surface layer can be modified by preparing the sample in different *** particles can be also obtained with different core composition and different size which we need.

关键词： preparing apparatus amorphous

spin and Pseudospin symmetries of Dirac Equation and the Yukawa Potential as the Tensor Interaction

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Communications in Theoretical Physics 2012年第12期58卷 807-814页

作者： H.Hassanabadi E.Maghsoodi s.Zarrinkamar Physics Department Shahrood University of Technology Department of Basic sciences Garmsar Branch Islamic Azad University

Considering of a tensor interaction in Dirac equation removes the degeneracy in spin and pseudospin doublets and consequently leads to results consistent with the experimental data. Here, instead of the commonly used Coulomb or linear terms, we investigate a tensor interaction of Yukawa form. We obtain arbitrary state solutions of Dirac equation under vector, scalar and tensor Yukawa potentials via a physical approximation and the Nikiforov-Uvarov methodology. The solutions are discussed in detail.

关键词： Dirac equation spin symmetry pseudospin symmetry tensor interaction Yukawa potential