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Structural,electronic,magnetic and optical properties of neodymium chalcogenides using LSdA+U method

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Journal of Semiconductors 2012年第8期33卷 9-14页

作者： A Shankar d P rai Sandeep r K Thapa Condensed Matter Theory Group Department of PhysicsMizoram UniversityAizawlMizoram-796004India

We have studied the electronic, magnetic and optical properties of neodymium chalcogenides by performing LSdA＋ U and full potential linearized augmented plane wave （FP-LAPW） method. The electronic structure calculation shows that the electronic states in Nd-chalcogenides were mainly contributed by Nd-4f electrons near Fermi energy and 3p, 4p and 5p state electrons of X （S, Se and Te）, respectively. We have also studied the absorption of light via the imaginary parts of the dielectric function of Nd-chalcogenides.

关键词： dFT dOS magnetic moment U

Testes extracts inhibit heart contractions in females of the blood-feeding insect, rhodnius prolixus

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Insect Science 2010年第4期17卷 386-392页

作者： Jocelyn d. Martens r. Gary Chiang Biology department Redeemer University College Ancaster Ontario Canada

Myogenic contractions of the heart of the female blood-feeding insect, rhodnius prolixus （Stal）, are inhibited by crude extracts of testes applied directly to isolated dorsal vessels. dorsal vessels were observed with a stereo microscope and heart beats timed with a stopwatch. In normal rhodnius saline, hearts contract at 14.8 4- 7.1 beats per minute （n = 45）. Crude extracts of the testes and the two male reproductive accessory organs （the opaque and transparent accessory glands） were prepared from previously frozen tissue by homogenizing 5-20 glands in a small glass homogenizer containing rhodnius saline, centrifuging for 5 rain at 2 000 g, and collecting the supernatant. Testes extract as low as 1.0 glands per mL inhibit contractions whereas crude extracts of the opaque or transparent accessory glands have no consistent effect. We refer to this cardiac inhibitor as rhodtestolin （rhodnius testis inhibitory factor）, and discuss its possible effects on the female during copulation.

关键词： cardiac inhibition copulation heart beat rhodnius rhodtestolin testis

Nutritive value of introduced bamboo species in the northwestern Himalayas, India

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Journal of Forestry research 2019年第6期30卷 2051-2060页

作者： d.r.Bhardwaj P.Sharma r.Bishist M.r.Navale r.Kaushal dr.Y.S.Parmar University of Horticulture and Forestry Solan 173 230India ICAr-Indian Institute of Soil and Water Conservation DehradunUttarakhandIndia

Bamboos are used extensively for a variety of purposes,and many new species have been introduced to the northwestern ***,their potential as a fodder species has not been *** bamboo species,namely dendrocalamus hamiltonii Gamble,dendrocalamus asper(*** Schult.f.)Backer ex ***,Melocanna baccifera(roxb.)Kurz,Phyllostachys aurea rivie′re and ***′re,Phyllostachys bambusoides Sieb and *** Phyllostachys pubescens(Pradelle)Mazel ex *** evaluated for their nutritional value,relative palatability and best lopping *** matter(dM),ether extract(EE),and crude fibre varied from(37.0-67.7)%,(4.7-7.6),and(22.1-37.9)%,*** of crude protein ranged from(12.2-17.1)%,total ash(TA)from(11.8-21.5)%,acid insoluble ash(AIA)from(0.3-0.5)%,nitrogen free extract from(31.1-40.8)%,carbohydrates from(57.0-69.0)%,organic matter(OM)from(78.5-88.2)%,calcium from(1.7-2.3)%,phosphorus from(0.4-0.8)%,potassium from,(0.9-1.6)%,magnesium from(0.5-0.9)%,sodium from(603.7-1072.7)×10^-6 and vitamin A from(21.1-30.5)×10^-2 mg/g,*** had maximum values for dM,EE,TA and *** and vitamin A were highest in *** and carbohydrates were maximized in *** and CP in *** the values obtained for different bamboo species were less than maximum tolerable concentration of common feed resources of the region thereby indicating their suitability for nutrition and *** contents of anti-nutritional factors,namely hydrocyanic acid and tannin ranged from(33.8-61.7)×10^-2 mg/g and(0.7-1.9)%,*** was the best species from a palatability point of view and has maximum crude protein content(17.2%),Ca(2.3%)and lowest tannin content(0.7%).The relative palatability of introduced bamboo species followed trend:***(97.6%)[***(92.5%)[***(81.2%)[***(76.9%)[***(75.9%)[***(73.4%).The optimum months for lopping these species for green leaves are Novem

关键词： Anti-nutritional values Nutritional values Bamboo Chemical composition Mineral nutrients Palatability Lopping time

Effect of Nd^(3+) on spectroscopic properties of lithium borate glasses

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Journal of rare Earths 2014年第12期32卷 1148-1153页

作者： d.d.ramteke K.Annapurna V.K.deshpande r.S.Gedam department of Applied Physics Visvesvaraya National Institute of Technology Glass Science and Technology Section CSIR-Central Glass and Ceramic Research Institute

The spectroscopic properties of lithium borate glasses as a function of Nd3＋ ions concentration were *** absorption spectra of these glasses showed a number of absorption bands in ultra violet and visible *** absorption edge was found to shift towards the longer wavelength（red shift） with increase in *** spectra revealed three major bands at 902, 1063 and 1334 nm which was due to 4F3/2→4I9/2, 11/2 ＆13/2 transitions of Nd3＋ *** intensity was maximum for 1 mol.% Nd2O3 and further increase in Nd2O3 resulted in luminescence *** luminescence quenching behavior at higher concentration of Nd2O3 was attributed to the Nd3＋-Nd3＋ interaction in the glass *** absorption and emission property of these glasses suggested that these glasses could be useful for 1.06 μm infrared laser applications.

关键词： glasses optical properties luminescence laser rare earths

LrS Bianchi Type-II Cosmological Model with a decaying Lambda Term

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Chinese Physics Letters 2012年第1期29卷 35-37页

作者： r.K.Tiwari d.Tiwari Pratibha Shukla department of Mathematics Govt.Model Science College RewaM.P.486001India

We consider a locally rotationally symmetric(LrS)Bianchi type-Ⅱspacetime with a perfect fluid and a variable cosmological constant∧.To solve the Einstein field equations we consider the cosmological term∧to be proportional to r^(-m) with r being the scale factor and m a constant[***.d 58(1998)043506].In this model we obtain∧~H^(2),∧~(r)/r and Larnbda~t^(-2),in agreement with the main dynamical laws for the decay of∧.The physical significance of the cosmological model is also discussed.

关键词： Bianchi Cosmo perfect

Friction Stir Welding of discontinuously reinforced Aluminum Matrix Composites:A review

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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 816-824页

作者： d.Wang B.L.Xiao d.r.Ni Z.Y.Ma Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

Friction stir welding （FSW） is considered a promising welding technique for joining the aluminum matrix composites （AMCs） to avoid the drawbacks of the fusion welding. High joint efficiencies of 60%-100% could be obtained in the FSW joints of AMCs. However, due to the existence of hard reinforcing particles in the AMCs, the wearing of welding tool during FSW is an unavoidable problem. Moreover, the low ductility of the AMCs limits the welding process window. As the hard materials such as Ferro-Titanit alloy, cermet, and WC/Co were applied to produce the welding tools, the wearing of the tools was significantly reduced and the sound joints could be achieved at high welding speed for the AMCs with low reinforcement volume fraction. In this article, current state of understanding and development of welding tool wearing and FSW parameters of AMCs are viewed. Furthermore, the factors affecting the microstructure and mechanical properties of the joints are evaluated in detail.

关键词： Metal matrix composite Friction stir welding Particle, microstructure Wear

Predictive approach of heterogeneous catalysis

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National Science review 2018年第5期5卷 633-635页

作者： Jean-Marie Basset Jérémie d.A.Pelletier King Abdullah University of Science and Technology

‘Predictive catalysis’ or ‘catalysis by design’ has recently advanced heterogeneous catalysis by using the conceptual tool of surface fragments [1] such as ‘surface organometallic fragments’(SOMF)or ‘surface coordination fragments’(SCF) to achieve and understand a presumed catalytic cycle (see Fig. 1).One or several fragments of the molecule

关键词： SCF Cr CO EXAFS

Impact of Clocking on the Aero-Thermodynamics of a Second Stator tested in a One and a Half Stage HP Turbine

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Journal of Thermal Science 2008年第2期17卷 97-110页

作者： N.Billiard G.Paniagua r.dénos Turbomachinery and Propulsion department von Karman Institute for Fluid dynamics

This paper focuses on the experimental investigation of the time-averaged and time-accurate aero- thermodynamics of a second stator tested in a 1.5 stage high-pressure turbine. The effect of clocking on aerodynamic and heat transfer are investigated. Tests are performed under engine representative conditions in the VKI compression tube CT3. The test program includes four different clocking positions, i.e. relative pitch-wise positions between the fh-st and the second stator. Probes located upstream and downstream of the second stator provide the thermodynamic conditions of the flow field. On the second stator airfoil, measurements are taken around the blade profile at 15, 50 and 85% span with pressure sensors and thin-film gauges. Both time-averaged and time-resolved aspects of the flow field are addressed. regarding the time-averaged results, clocking effects are mainly observed within the leading edge region of the second stator, the largest effects being observed at 15% span. The surface static pressure distribution is changed locally, hence affecting the overall airfoil performance. For one clocking position, the thermal load of the airfoil is noticeably reduced. Pressure fluctuations are attributed to the passage of the up- stream transonic rotor and its associated pressure gradients. The pattern of these fluctuations changes noticeably as a function of docking. The time-resolved variations of heat flux and static pressure are analyzed together showing that the major effect is due to a potential interaction. The time-resolved pressure distribution integrated along the second stator surface yields the unsteady forces on the vane. The magnitude of the unsteady force is very dependent on the clocking position.

关键词： transonic flow turbines stator clocking forces heat transfer.

Electrodeless plasma thrusters for spacecraft: a review

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Plasma Science and Technology 2017年第8期19卷 1-24页

作者： S N BATHGATE M M M BILEK d r MCKENZIE Applied and Plasma Physics School of PhysicsUniversity of Sydney

The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more durable than presently deployed thrusters that use electrodes such as gridded ion,Hall thrusters, arcjets and resistojets. Like other plasma thrusters, electrodeless thrusters have the advantage of reduced fuel mass compared to chemical thrusters that produce the same thrust. The status of electrodeless plasma thrusters that could be used in communications satellites and in spacecraft for interplanetary missions is examined. Electrodeless thrusters under development or planned for deployment include devices that use a rotating magnetic field; devices that use a rotating electric field; pulsed inductive devices that exploit the Lorentz force on an induced current loop in a plasma; devices that use radiofrequency fields to heat plasmas and have magnetic nozzles to accelerate the hot plasma and other devices that exploit the Lorentz force. Using metrics of specific impulse and thrust efficiency, we find that the most promising designs are those that use Lorentz forces directly to expel plasma and those that use magnetic nozzles to accelerate plasma.

关键词： spacecraft a review propellant Lorentz thrust rotating radiofrequency erosion presently exploit