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咔唑类农药特性的一些研究

农药译丛 1991年第4期13卷 43-43,15页

作者： b.p.das 张曙明王有生印度桑蒂尼克坦Visva-bharati化学部

研究咔唑类农药特性的主要目的是发掘具有低的生产成本的潜在的咔唑类农药,它可以消灭病原微生物、家蝇和幼蚊以防止环境污染。咔唑类物质是具有生物活性的物质。据此具有农药特性的或许可大致分成:(1)咔唑类生物碱及其相关产物;(2)部... 详细信息

研究咔唑类农药特性的主要目的是发掘具有低的生产成本的潜在的咔唑类农药,它可以消灭病原微生物、家蝇和幼蚊以防止环境污染。咔唑类物质是具有生物活性的物质。据此具有农药特性的或许可大致分成:(1)咔唑类生物碱及其相关产物;(2)部分还原的咔唑类物质;(3)N-取代的咔唑类物质和(4)其他咔唑类衍生物,如硝基咔唑类物质等。

关键词：农药咔喹杀虫剂

Anisotropic strange quark star in Finch-Skea geometry and its maximum mass for non-zero strange quark mass(m_(s)≠0)

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Chinese physics C 2023年第5期47卷 195-210页

作者： b.das K.b.Goswami A.Saha p.K.Chattopadhyay Department of physics Coochbehar Panchanan Barma UniversityVivekananda StreetCoochbehar 736101West BengalIndia Department of physics Alipurduar CollegeAlipurduar 736122West BengalIndia

A class of relativistic astrophysical compact objects is analyzed in the modified Finch-Skea geometry described by the MIT bag model equation of state of interior matter,p=1/3(ρ-4b),where b is known as the bag constant.b plays an important role in determining the physical features and structure of strange *** consider the finite mass of the strange quark(m_(s)≠0) and study its effects on the stability of quark matter inside a *** note that the inclusion of strange quark mass affects the gross properties of the stellar configuration,such as maximum mass,surface red-shift,and the radius of strange quark *** apply our model physically,we consider three compact objects,namely,(ⅰ) VELA X-1,(ⅱ) 4U 1820-30,and(ⅲ) pSR J 1903+327,which are thought to be strange *** range of b is restricted from 57.55 to bstable(MeV/fm3),for which strange matter might be stable relative to iron(^(56)Fe).However,we also observe that metastable and unstable strange matter depend on b and *** energy conditions hold well in this *** in terms of the Lagrangian perturbation of radial pressure is studied in this paper.

关键词： compact star strange star anisotropy MIT EoS strange quark mass

Magnetic and flotation studies of banded hematite quartzite (bHQ) ore for the production of pellet grade concentrate

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 675-682页

作者： b. das b.K.Mishra S. prakash S.K.das p.S.R.Reddy S.I.Angadi Institute of Minerals and Materials Technology Council of Scientific & Industrial Research (CSIR)

To identify and establish beneficiation techniques for banded hematite quartzite （bHQ） iron ore, a comprehensive research on bHQ ore treatment was carried out. The bHQ ore was assayed as 38.9wt% Fe, 42.5wt% SiO2, and 1.0wt% Al2O3. In this ore, hematite and quartz are present as the major mineral phases where goethite, martite, and magnetite are present in small amounts. The liberation of hematite particles can be enhanced to about 82% by reducing the particle size to below 63 μm. The rejection of silica particles can be obtained by magnetic and flotation separation techniques. Overall, the bHQ ore can be enriched to 65.3wt% Fe at 61.9% iron recovery. A flowsheet has been suggested for the commercial exploitation of the bHQ ore.

关键词： hematite beneficiation magnetic separation flotation pelletizing

An Intelligent Multi-robot path planning in a Dynamic Environment Using Improved Gravitational Search Algorithm

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International Journal of Automation and computing 2021年第6期18卷 1032-1044页

作者： p.K.das H.S.behera p.K.Jena b.K.panigrahi Department of Computer Sceime and Engineering and Information TechnologyVeer Surendra Sai University of TechnologyBurlaOdishaIndia Departmet of Mechanical Engineering Veer Surendra Sai University of TechnologyBurlaOdishaIndia Departmet of Electrical Engineering Indian Institute of TechnologyDelhiIndia

This paper proposes a new methodology to optimize trajectory of the path for multi-robots using improved gravitational search algorithm(IGSA) in clutter environment. Classical GSA has been improved in this paper based on the communication and memory characteristics of particle swarm optimization(pSO). IGSA technique is incorporated into the multi-robot system in a dynamic framework, which will provide robust performance, self-deterministic cooperation, and coping with an inhospitable environment. The robots in the team make independent decisions, coordinate, and cooperate with each other to accomplish a common goal using the developed IGSA. A path planning scheme has been developed using IGSA to optimally obtain the succeeding positions of the robots from the existing position in the proposed environment. Finally, the analytical and experimental results of the multi-robot path planning were compared with those obtained by IGSA, GSA and differential evolution(DE) in a similar environment. The simulation and the Khepera environment result show outperforms of IGSA as compared to GSA and DE with respect to the average total trajectory path deviation, average uncovered trajectory target distance and energy optimization in terms of rotation.

关键词： Gravitational search algorithm multi-robot path planning average total trajectory path deviation average uncovered trajectory target distance average path length

Dielectric relaxation and magneto-electric characteristics of lead-free double perovskite: Sm2NiMnO6

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Journal of Advanced Ceramics 2019年第2期8卷 174-185页

作者： Rutuparna das R.N.p.CHOUDHARY Department of physics Siksha ‘O’ Anusandhan University

The polycrystalline sample of a double perovskite, Sm2NiMnO6 was synthesized by a solid-state reaction route. From the X-ray structural study, it is found that the structure of the material is monoclinic with lattice parameters: a = 4.1750(63) ?, b = 7.6113(63) ?, c = 5.9896(63) ?, and β = 112.70°. These parameters are very close to and consistent with those of such type of materials. The dielectric, impedance, AC conductivity, and electrical modulus properties of the sample were studied in the temperature range of 25–300℃ and the frequency range of 1 kHz–1 MHz. Typical relaxor behavior observed in the dielectric studies was confirmed by Vogel–Fulcher fitting. From the Nyquist plots, the temperature dependent contribution of grain and grain boundary effect was confirmed. The non-Debye type of relaxation was found using the complex impedance spectroscopy. The magnetic study revealed that the sample had paramagnetic behavior at room temperature. Magneto-electric(ME) coefficient was obtained by changing DC bias magnetic field. This type of lead-free relaxor ferroelectric compound may be useful for high-temperature applications.

关键词： solid-state reaction X-ray diffraction(XRD) dielectric relaxation magneto-electric(ME) coupling

Effect of equiproprotional substitution of Zn and Mn in baTiO_(3)ceramic-An index to multiferroic applications

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Journal of Advanced Ceramics 2012年第3期1卷 241-248页

作者： S.K.das p.p.ROUT S.K.pRADHAN b.K.ROUL Institute of Materials Science Planetarium BuildingAcharya ViharBhubaneswar 751013India

This paper reports that ferromagnetism(FM)can be induced in ferroelectric barium titanate(baTiO_(3))ceramic with selection of appropriate substituents like Zn and *** density polycrystalline samples of Zn and Mn substituted baTiO_(3)(ba_(1-x)Zn_(x)Ti_(1-x)Mn_(x)O_(3),x=0,0.02,0.04,0.06,0.08 and 0.1)were prepared using slow step solid state sintering technique to study the effect of equiproprotional substituents on structural,ferroelectric and magnetic properties of baTiO_(3)(bTO).High precision electrical and magnetic measurements were carried out along with XRD,XpS,and SEM to understand and co-relate magnetic and ferroelectric hysteresis loop observed at room temperature with different values of‘x’.It is seen that ferroelectric hysteresis loop(p~E)is deteriorated(became lossy type)with the increase of Zn and Mn ***,at x=0.1,the material showed the signature of room temperature ferromagnetism,which is an index for bTO to became a promising material for multiferroic applications.M~H loops observed in Zn and Mn substituted bTO are expected to be due to the formation of oxygen vacancies and exchange interaction induced magnetism.

关键词： ceramic magnetism hexagonal polarization

Optimization of flotation variables for the recovery of hematite particles from bHQ ore

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International Journal of Minerals,Metallurgy and Materials 2013年第7期20卷 605-611页

作者： Swagat S. Rath Hrushikesh Sahoo b. das CSIR-Institute of Minerals and Materials Technology Bhubaneswar 751 013 India

The technology for beneficiation of banded iron ores containing low iron value is a challenging task due to increasing demand of quality iron ore in India. A flotation process has been developed to treat one such ore, namely banded hematite quartzite （bHQ） containing 41.8wt% Fe and 41.5wt% SiO2,by using oleic acid, methyl isobutyl carbinol （MIbC）, and sodium silicate as the collector, frother, and dispersant, respectively. The relative effects of these variables have been evaluated in half-normal plots and pareto charts using central composite rotatable design. A quadratic response model has been developed for both Fe grade and recovery and optimized within the experimental range. The optimum reagent dosages are found to be as follows： collector concentration of 243.58 g/t, dispersant concentration of 195.67 g/t, pH 8.69, and conditioning time of 4.8 min to achieve the maximum Fe grade of 64.25% with 67.33% recovery. The predictions of the model with regard to iron grade and recovery are in good agreement with the experimental results.

关键词： hematite iron ore treatment flotation metal recovery design of experiments mathematical models opti-mization

Effect of Zn Concentration on Microstructural,Optical,and Hyperfine properties of Nanocrystalline a-Fe_(2)O_(3)

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Acta Metallurgica Sinica(English Letters) 2014年第4期27卷 563-568页

作者： N.R.panda D.Sahu b.S.Acharya p.Nayak S.p.pati D.das School of basic Science Indian Institute of Technology BhubaneswarBhubaneswar 751013OdishaIndia School of physics Sambalpur UniversitySambalpur 768019OdishaIndia School of Chemistry Sambalpur UniversitySambalpur 768019OdishaIndia C.V.Raman College of Engineering Bhubaneswar 752054OdishaIndia Department of Electronic Engineering Tohoku UniversitySendai 980-8579Japan UGC-DAE CSR Sector IIILB-8Bidhan NagarKolkata 700098India

Efforts have been made to prepare nanocomposites of a-Fe2O3-ZnO by wet chemical route with varying concentrations of the *** microstructural properties of the samples are investigated by powder X-ray diffractometry（pXRD） and Transmission electron *** concentration of Zn ions（up to 20 at%） leads to the formation of nanocomposites of a-Fe2O3 and *** of ZnFe2O4 phase is detected by the substitution of higher concentration of Zn2？（30 at%） in the *** average size of the nanoparticles remains in the range of 22–27 nm as obtained from XRD *** results obtained from electron microscopic studies are also close to these *** measurement shows the excitonic peak of ZnO around 390 nm which gets strengthened with Zn *** spectra show the metal–oxygen band below 700 *** temperature Mssbauer studies of the samples show the transition of iron oxide form antiferromagnetic state to paramagnetic state with increasing concentration of Zn2？.Sharp quenching of hyperfine field with Zn concentration is observed as the Hintvalue reduced to zero from 51 T.

关键词： Iron oxide ZnO Electron microscopy Mssbauer study

Enhanced performance of Discharge plasma in Raw Engine Exhaust Treatment-Operation under Different Temperatures and Loads

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plasma Science and Technology 2005年第4期7卷 2943-2946页

作者： b S Rajanikanth A D Srinivasan Subhankar das Dept.of High Voltage Engineering Indian Institute of Science Bangalore 560012IndiaDept.of High Voltage Engineering Indian Institute of ScienceBangalore 560012IndiaDept.of High Voltage Engineering Indian Institute of ScienceBangalore 560012India

This paper reports improved performance of discharge plasma in raw engine exhaust treatment. For the purpose of investigation, both filtered and raw diesel engine exhaust were separately treated by the discharge plasma. In raw exhaust environment, the discharge plasma exhibits a superior performance with regard to NOx removal, energy consmnption and formation of by-products. In this study, experiments were conducted at conditions of different temperatures and loads.

关键词： raw diesel engine exhaust discharge plasma NOx removal