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高电压技术 2008年第12期34卷 2642-2647页

作者： M. venu Gopala rao J. Amarnath G.v. Nagesh Kumar s. Kamakshaiah K. D. srivastava QIs College of Engineering and Technology Ongole 523272 Andhra Pradesh India College of Engineering Jawaharlal Nehru Technological University Kuktrtpally Hyderabad 500085 Andhra Pradesh India vignan's Institute of Information Technology Visakhapatnam 530046 Andhra Pradesh India C. v. R. College of Engineering Hyderabad Andhra Pradesh India University of British Colombia vancouver B. C. V6T 1Z4 Canada

Transient over voltages due to lightning and switching surges cause steep build-up of voltage on transmission lines and other electrical apparatus,like circuit breakers,transformers,insulators *** it is necessary for the GIs also to withstand such voltages without breakdown of *** system has to be tested under these *** the GIs system operates on power *** Impulse voltage of 1050 kv and switching Impulse voltage of 750 kv superimposed on Power frequency voltages of 75 kv,100 kv and 132 kv are applied to single Phase Gas Insulated Busduct and the maximum movement of Aluminum,Copper and silver particles is *** movement patterns are also determined with and without Monte Carlo simulation for movement of particle in axial and radial *** results show that there is a sudden jump in the movement at the application of impulse on sine *** is because of high magnitude voltage of 1050 kv during 1.2/50 μ*** movement patterns of reduced maximum movement is observed for switching Impulse superimposed on sine *** results are presented and analyzed.

关键词：重复雷击金属微粒运动形态气相绝缘站粒子污染物

Jatropha oil methyl ester and its blends used as an alternative fuel in diesel engine

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International Journal of Agricultural and Biological Engineering 2008年第2期1卷 32-38页

作者： Y.v.Hanumantha rao Ram sudheer voleti v.s.Hariharan A.v.sitarama Raju Department of Mechanical Engineering Koneru Lakshmaiah College of EngineeringGreen FieldsGuntur-522502Andhra PradeshIndia Department of Mechanical Engineering Lakireddy Balireddy College of EngineeringMylavaramKrishna DtAndhra PradeshIndia Department of Mechanical Engineering Jawaharalal Nehru Technological University College of EngineeringKakinadaPin:533003Andhra PradeshIndia

Biomass derived vegetable oils are quite promising alternative fuels for agricultural diesel *** of vegetable oils in diesel engines leads to slightly inferior performance and higher smoke emissions due to their high *** performance of vegetable oils can be improved by modifying them through the transesterification *** this present work,the performance of single cylinder water-cooled diesel engine using methyl-ester of Jatropha oil as the fuel was evaluated for its performance and exhaust *** fuel properties of biodiesel such as kinematic viscosity,calorific value,flash point,carbon residue and specific gravity were *** indicate that B25 has closer performance to diesel and B100 has lower brake thermal efficiency mainly due to its high viscosity compared to *** brake thermal efficiency for biodiesel and its blends was found to be slightly higher than that of diesel fuel at tested load conditions and there was no difference of efficiency between the biodiesel and its blended *** Jatropha biodiesel and its blended fuels,the exhaust gas temperature increased with the increase of power and amount of ***,its diesel blends showed reasonable efficiencies,lower smoke,CO_(2),CO and HC emissions.

关键词： Jatropha oil bio-fuels transesterification performance and emission characteristics

Beneficiation of an Indian non-coking coal by column flotation

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International Journal of Coal science & Technology 2016年第2期3卷 206-214页

作者： N. vasumathi T. v. vijaya Kumar s. Ratchambigai s. subba rao s. Prabhakar G. Bhaskar Raju CsIR-National Metallurgical Laboratory Madras Centre CSIR Madras Complex Taramani Chennai 600 113 India

Beneficiation of non-coking coal is gaining ground in India. It not only reduces the volume of inert content to be transported to the power plant and also lowers the wear in the boiler houses. For special applications such as the fuel for integrated gasification combined cycle plant （IGCC）, the ash content in the coal should preferably be below 15 %. Indian coals are characterized by high inter-grown ash content mainly due to ＇drift origin＇ of Gondwana formation in Permian age. This warrants fine grinding of non-coking coal in order to liberate the ash forming minerals from coal macerals. A non- coking coal sample of vitrinite type from India was ground to 44 ~tm （dso） and subjected to column flotation to improve its quality. The non-coking coal analyzing 34.6 % ash, 26.2 % volatile matter, 1.3 % moisture and 37.9 % fixed carbon could be upgraded to a concentrate/froth of 14.83 % ash at 72.18 % yield by optimizing collector and frother dosages and flotation column operating parameters, namely, froth depth, superficial feed velocity and superficial air velocity. The concentrate produced by this process is suitable as fuel for IGCC in coal-to-electricity route.

关键词： Non-coking coal Washability Beneficiation Column flotation Coal gasification

Microcontroller-Based variable speed Drive for Three-Phase Induction Motor in Cooling Applications

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Journal of Energy and Power Engineering 2012年第4期6卷 656-662页

作者： Kondapalli s.v. rama rao Lee Teng Hong Department of Electrical and Electronics Engineering Universiti Teknologi PETRONAS Tronoh 31750 Malaysia

This paper presents an electronic vsD （variable speed drive） for three-phase IM （induction motor） using a microcontroller. The vsD is designed for cooling applications where the 1M is coupled to a cooling fan. The drive receives temperature feedback from objects to be cooled and output a corresponding frequency to the IM. A prototype of the vsD is constructed to control a 175 W, four pole, squirrel cage three-phase IM. The heart of the control circuit is a low-cost microchip＇s PICI6F777 microcontroller which is programmed using C language to generate variable frequency sPWM （sinusoidal pulse width modulation） switching signals. These switching signals are fed to an 1GBT inverter. The vsD constructed can be switched between two modes of speed control＂ automatic temperature-controlled mode and manual user-controlled mode. Cost s.v.ngs using the prototype are demonstrated.

关键词： IGBT inverter PIC microcontroller sPWM three-phase induction motor variable speed drive.

spectroscopic investigations on Dy^(3+) ions doped zinc lead alumino borate glasses for photonic device applications

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Journal of Rare Earths 2019年第1期37卷 52-59,M0004页

作者： Nisha Deopa shubham saini sumandeep Kaur Aman Prasad A.s.rao Department of Applied Physics Delhi Technological University

This paper presents the structural, optical absorption, photoluminescence (PL) and decay spectral properties of Dy^(3+)ions doped zinc lead alumino borate (ZPAB) glasses to elucidate their possible usage in photonic devices such as w-LEDs and lasers. A broad hump shown by the XRD spectrum recorded for an un-doped ZPAB glass confirms its non-crystalline nature. The Judd-Ofelt (J-O) intensity parameter evaluated from the measured oscillator strengths of the absorption spectral features were used to estimate various radiative parameters and also to understand the nature of bonding between Dy^(3+)ions and oxygen ligands. Under 350 nm excitation, the as-prepared glasses are exhibiting two emission bands^4F_(9/2)→~6H_(15/2)(blue),and^4F_(9/2)→~6H_(13/2)(yellow) at 483 and 575 nm,respectively. From the PL spectra,the Y/B ratio values, CIE chromaticity color coordinates and color correlated temperature (CCT) were evaluated. The experimental lifetimes measured from the decay profiles are decreasing with increase in Dy^(3+)ions concentration in these glasses which may be attributed to the cross-relaxation and nonradiative multiphonon relaxation process. Decay profiles observed for higher concentration were well fitted to Inokuti-Hirayama (I-H) model to understand the energy transfer process and subsequent decrease in experimental lifetimes. The higher values of radiative parameters, emission cross-sections,quantum efficiency, optical gain and gain band width suggest the suitability of 0.5 mol%of Dy^(3+) ions in these ZPAB glasses for the photonic device application.

关键词： Glasses J-O parameters Luminescence Inokuti-Hirayama model Energy transfer Rare earths

Reconstructing phase diagrams from local measurements.v.a Gaussian processes:mapping the temperature-composition space toconfidence

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npj Computational Materials 2018年第1期4卷 451-461页

作者： Dhiren K.Pradhan shalini Kumari Evgheni strelcov Dillip K.Pradhan Ram s.Katiyar sergei v.Kalinin Nouamane Laanait rama K.vasudevan Department of Physics and Institute of Functional Nanomaterials University of Puerto Rico san Juan PR 00936 USA Institute for Research in Electronics and Applied Physics University of MarylandCollege ParkMD 207425USA Department of Physics&Astronomy National Institute of TechnologyRourkela 769008India Center for Nanophase Materials sciences Oak Ridge National Laboratory Oak Ridge TN 37831 UsA Institute for Functional Imaging of Materials Oak Ridge National LaboratoryOak RidgeTN 37831USA Geophysical Laboratory Carnegie Institution for ScienceWashingtonDC 20015USA Department of Physics and Astronomy West Virginia UniversityMorgantownWV 26506USA

We show the ability to map the phase diagram of a relaxor-ferroelectric system as a function of temperature and composition through local hysteresis curve acquisition,with the voltage spectroscopy data being used as a proxy for the(unknown)microscopic state or thermodynamic parameters of *** the discrete nature of the measurement points,we use Gaussian processes to reconstruct hysteresis loops in temperature and voltage space,and compare the results with the raw data and bulk dielectric spectroscopy *** results indicate that the surface transition temperature is similar for all but one composition with respect to the *** clustering algorithms,we recreate the main features of the bulk diagram,and provide statistical confidence estimates for the reconstructed phase transition *** validate the method by using Gaussian processes to predict hysteresis loops for a given temperature for a composition unseen by the algorithm,and compare with *** techniques can be used to map phase diagrams from functional materials in an automated fashion,and provide a method for uncertainty quantification and model selection.

关键词： materials hysteresis phase

Experimental studies on the self-shielding Effect in Fissile Fuel Breeding Measurement in Thorium Oxide Pellets Irradiated with 14 Mev Neutrons

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Plasma science and Technology 2013年第2期15卷 166-170页

作者： Mitul ABHANGI Nupur JAIN Rajnikant MAKWANA sudhirsinh vALA shrichand JAKHAR T. K. BAsU C. v. s. rao Fusion Neutronics Laboratory Institute for Plasma ResearchBhat Gandhinagar-382428Gujarat India school of Nuclear Energy Pandit Deendayal Petroleum UniversityGandhinagarGujarat 382007 India

The 14 Mev neutrons produced in the D-T fusion reactions have the potential of breeding Uranium-233 fissile fuel from fertile material Thorium-232. In order to estimate the amount of U-233 produced, experiments are carried out by irradiating thorium dioxide pellets with neutrons produced from a 14 Mev neutron generator. The objective of the present work is to measure the reaction rates of 232Th ＋ in --＊ 233Th --＊ 2a^Pa --＊ 2a3U in different pellet thicknesses to study the self-shielding effects and adopt a procedure for correction. An appropriate assembly consisting of high-density polyethylene is designed and fabricated to slow down the high-energy neutrons, in which Thorium pellets are irradiated. The amount of fissile fuel （~3~U） produced is estimated by measuring the 312 kev gammas emitted by Protactinium-233 （half-life of 27 days）. A calibrated High Purity Germanium （HPGe） detector is used to measure the gamma ray spectrum. The amount of 233U produced by Th232 （n, ~） is calculated using MCNP code. The self-shielding effect is evaluated by calculating the reaction rates for different foil thickness. MCNP calculation results are compared with the experimental values and appropriate correction factors are estimated for self-shielding of neutrons and absorption of gamma rays.

关键词： 233U breeding fissile fuel MCNP 14 Mev neutron source

Development and Identification of Novel Rice Blast Resistant sources and Their Characterization Using Molecular Markers

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Rice science 2015年第6期22卷 300-308页

作者： s.J.s.rama DEvI Kuldeep sINGH B.UMAKANTH B.vIsHALAKsHI P.RENUKA K.vIJAY sUDHAKAR M.s.PRAsAD B.C.vIRAKTAMATH v.RAvINDRA BABU M.s.MADHAv Biotechnology Crop ImprovementIndian Institute of Rice ResearchIndian Council of Agriculture Research school of Agricultural Biotechnology Punjab Agricultural University Plant Pathology Indian Institute of Rice ResearchIndian Council of Agriculture Research

To develop and characterize introgression lines for leaf and neck blast resistance, 326 introgression lines were developed using various accessions of six different AA genome wild species in the genetic background of elite Indian varieties like PRl14 and Pusa 44 and were screened for blast resistance. stringent phenotyping coupled with genotyping using gene based markers led to the identification of four resistant introgression lines, which showed promising resistance and do not possess any of the tested genes. Furthermore, multi-location screening confirmed the field resistance of the four introgression lines to both leaf and neck blast. Molecular characterization of these introgression lines using genome-wide simple sequence repeat markers revealed the presence of small percentage of wild Oryza genome introgrssion. so these lines can be used for mapping and identification of novel leaf and neck blast resistance genes. Thus, these four introgression lines can be considered as new genetic resources for blast resistance.

关键词： rice blast resistance introgression line gene profiling wild species

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带反偏置的双路高压脉冲电源的研究

强激光与粒子束 2024年第3期36卷 134-141页

作者：李孜张迪姜松王永刚饶俊峰上海理工大学机械工程学院上海200093 中国科学院苏州生物医学工程技术研究所江苏苏州215163

通过调节反向偏置电压可以改善电场渗透对质谱仪的影响,提高质谱仪的分辨率。为了满足质谱仪对脉冲电场的不同要求,提出了一种可以同时输出两路极性相反脉冲电场的脉冲电源,且高压正脉冲叠加幅值可调的直流负偏置电压。该电源只需一个... 详细信息

通过调节反向偏置电压可以改善电场渗透对质谱仪的影响,提高质谱仪的分辨率。为了满足质谱仪对脉冲电场的不同要求,提出了一种可以同时输出两路极性相反脉冲电场的脉冲电源,且高压正脉冲叠加幅值可调的直流负偏置电压。该电源只需一个充电源便可以产生正负两路脉冲电场。分析了串联开关同步驱动效果,随后通过增加补偿绕组和并联电阻优化了串联电容的分压不均的问题,并验证一个磁芯加多个副边绕组的方案可进一步降低充电电压不均。最终实现了4个电容器的充电电压与平均电压相差不超过0.1%。搭建了一台4级的电源样机,实验表明,其可以在容性负载上产生一路幅值为0~1.5 kv、脉宽为2~10μs可调的高压正脉冲且叠加幅值为0~-200 v的反向偏置电压,和一路幅值为0~-1.5 kv、脉宽为2~10μs可调的高压负脉冲,频率高达10 kHz,正负脉冲的前沿均小于30 ns,脉冲波形平稳。该脉冲电源结构紧凑,并且输出电压、脉宽、频率均连续可调。

关键词：高压脉冲电源脉冲发生器脉冲电场方波脉冲谐振充电

A New species of Japalura(squamata, Agamidae) from the Nu River valley in southern Hengduan Mountains, Yunnan, China

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Asian Herpetological Research 2017年第2期18卷 86-95页

作者： Dingqi rao Jens.v.vINDUM Xiaohui MA Mingxia FU Jeffery A.WILKINsON Kunming Institute of Zoology Chinese Academy of Sciences Department of Herpetology California Academy of Sciences

A population of Japalura from Yunnan Province, China, previously assigned to Japalura splendida, is described as a new species. The new species has been recorded between 1 138–2 500 m in the Nu River drainage between the towns of Liuku and Binzhongluo, and on the lower western slopes of the Nushan and eastern slopes of the Goaligongshan. The new species can be distinguished from other species of Japalura, except J. dymondi, by the following combination of characters： exposed tympani, prominent dorso-lateral stripes, and small gular scales. It is.v.ry similar with but differs from J. dymondi by having smooth or feebly keeled dorsal head scales, three relatively enlarged spines on either side of the post-occiput area, strongly keeled and mucronate scales on occiput area and within the lateral stripes, back of arm and leg green, higher number of dorsal-ridge scales（Ds） and fourth toe subdigital scales（T4s）. A principal component analysis of body measurements of adult male specimens of the new species and J. dymondi showed principal component 1 loading highest for upper arm length, fourth toe length and snout to eye length and principal component 2 loading highest for head width, head length and fourth toe length.

关键词： Agamidae Japalura sp.nov. Goaligongshan Mountain Nujiang River valley Hengduan Mountains Yunnan China