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Synthesis and Biological Study of Some 4-oxo-Thiazolidine derivatives of 2-Aminothiazole

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Chinese Journal of Chemistry 2011年第5期29卷 1001-1010页

作者： Samadhiya Pushkal Sharma Ritu srivastava Santosh k. srivastava Savitri d. Synthetic Organic Chemistry Laboratory Department of Chemistry Dr. H.S. Gour University (A Central University) Sagar M.P. 470003 India

Conventional and microwave assisted synthesis of new series of N-[2-{2-（substituted phenyl）-4-oxo- 5-（substituted benzylidene）-1,3-thiazolidine}-iminoethyl]-2-aminothiazole 5a-Sin have been developed. The cycloaddition reaction of thioglycolic acid with N-{2-（substituted benzylidenehydrazino）-ethyl}-2-aminothiazole 3a--3m in the presence of anhydrous ZnC12 afforded new heterocyclic compounds N-[2-{2-（substituted phenyl）- 4-oxo-l,3-thiazolidine}-iminoethyl]-2-aminothiazole 4a---4m. The later product on treatment with several selected substituted aromatic aldehydes in the presence of C2HsONa undergoes knoevenagel reaction to yield 5a--Sin. The structures of compounds 1, 2, 3a--3m, 4a---4m and 5a--Sm were confirmed by IR, IH NMR, 13C NMR, FAB-Mass and chemical analysis. All above compounds were screened for their antimicrobial activities against some selected bacteria and fungi and antituberculosis study against M. tuberculosis.

关键词： conventional microwave synthesis 2-aminothiazole 4-oxo-thiazolidine antimicrobial antitubercular

Synthesis of N1-3-{（4-Substituted aryl-3-chloro-2-oxo- azetidine）-iminocarbamyl}-propyl-6-nitroindazole derivatives and Their Biological Significance

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Chinese Journal of Chemistry 2011年第8期29卷 1745-1752页

作者： Samadhiya, Pushkal Sharma, Ritu srivastava, Santosh k. srivastava, Savitri d. Synthetic Organic Chemistry Laboratory Department of Chemistry Dr. H. S. Gour University (A Central Univer- sity) Sagar M.P. 470003 India

Synthesis of N1-3-{（4-substitute daryl-3-chloro-2-oxo-azetidine）-iminocarbamyl}-propyl-6-nitroindazole 4a-- 4s was conducted by a conventional method. All the compounds were synthesized and characterized by IR, 1H NMR, 13C NMR, FAB-Mass techniques and chemical methods. All the final synthesized compounds were evaluated for their antimicrobial activity and antitubercular activity with MIC values against some selected microorganisms.

关键词： synthesis 6-nitroindazole 2-azetidinone biological activity

Review of near-shore satellite derived bathymetry: Classification and account of five decades of coastal bathymetry research

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Journal of Ocean Engineering and Science 2021年第4期6卷 340-359页

作者： Mohammad Ashphaq Pankaj k srivastava d Mitra National Hydrographic Office DehradunIndia University of Petroleum&Energy Studies(UPES) DehradunIndia Indian Institute of Remote Sensing DehradunIndia

The number of civilian,commercial and military applications are dependant on accurate knowledge of bathymetry of coastal ***,hydrographic surveying methods are used for bathymetric surveys carried by ship-based acoustic systems,but needs highcost *** technology has provided a cost-effective alternate means for charting near shore and inaccessible *** optical satellite data have capabilities to offer alternate solution in near-shore region,which has been researched for past 50 years,using evolving algorithms to estimate Satellite derived Bathymetry(SdB).However,there is no agreement on use of terms like approach,model,method and techniques,which have been used varyingly and interchangeably as per context of SdB *** paper suggests a classification scheme for SdB algorithms which is also applicable to other Marine Remote Sensing *** this paper,based on literature available on SdB for the past five decades,an insight on SdB classification has been offered grounded in research *** SdB approaches,models,methods and techniques have been elaborated with chronological development,along with SdB studies based on them,their accuracy and errors in SdB *** have suggested a matrix of prerequisite satellite data,in-situ data resolution,methods and algorithms of SdB based on level of accuracy needs to be achieved,which will guide future researchers to select one as per their context of research.

关键词： Satellite derived bathymetry Hydrography Bio-optical model Physio-optical model

Synthesis and enhanced photoluminescence properties of red emitting divalent ion(Ca^(2+))doped Eu:Y_(2)O_(3)nanophosphors for optoelectronic applications

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Journal of Rare Earths 2022年第8期40卷 1187-1198页

作者： Arpita dwivedi Monika srivastava Ankur dwivedi Amit srivastava Anurag Mishra S.k.srivastava department of Physics Institute of ScienceBanaras Hindu University(BHU)Varanasi221005India School of Materials Science and Technology Indian Institute of Technology(BHU)Varanasi221005India department of Mining Engineering Indian Institute of Technology(BHU)Varanasi221005India department of Physics TdPG College VBS Purvanchal UniversityJaunpur222001India

This work presents the synthesis of Y_(2)O_(3):Eu^(3+),χCa^(2+)(χ=0 mol%,1 mol%,3 mol%,5 mol%,7 mol%,9 mol%,11 mol%)nanophosphors with enhanced photoluminescence properties through a facile solution combustion method for optoelectronic,display,and lighting *** X-ray diffraction(XRd)patterns of the proposed nanophosphor reveal its structural properties and crystalline *** transmission electron microscope(TEM)results confirm the change in the shape of the particle and aggregation of particles after co-doping with Ca^(2+).Fourier transform infrared spectroscopy(FTIR)and Raman vibrations also confirm the presence of Y-O vibration and subsequently explain the crystalline nature,structural properties,and purity of the *** the synthesized nanophosphors samples emit intense red emission at 613 nm(~5d_(0)→~7 F_(2))under excitation with 235,394 and 466 nm wavelengths of Eu^(3+)*** photoluminescence(PL)emission spectra excited with 235 nm illustrate the highest emission peak with two other emission peaks excited with 466 and 394 nm that is 1.4 times higher than 466 nm and 1.9 times enhanced by 394 nm wavelength,*** emission intensity of Y_(2)O_(3):Eu^(3+),χCa^(2+)(5 mol%)is increased 8-fold as compared to Eu:Y_(2)O_(3).doping with Ca^(2+)ions enhances the emission intensity of Eu:Y_(2)O_(3)nanopho sphors due to an increase in energy transfer in Ca^(2+)→Eu^(3+)through asymmetry in the crystal field and by introduction of radiative defect centers through oxygen vacancies in the yttria *** is also observed that the optical band gap and the lifetime of the~5d_(0)level of Eu^(3+)ions in Y_(2)O_(3):Eu^(3+),xCa^(2+)nanophosphor sample gets changed with a doping conce ntration of Ca^(2+)*** also reveals high thermal stability and quantum yield as estimating activation energy of 0.25 eV and 81%,***,CCT,and color purity values(>98%)show an improved red-emitting nanophosphor in the warm region of light,which m

关键词： Red emission Photoluminescence(PL) Y_(2)O_(3):Eu^(3+),xCa^(2+) Rare earths Nanophosphors LEds

Establishment of high frequency shoot regeneration system in Himalayan poplar(Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

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Journal of Forestry Research 2015年第3期26卷 651-656页

作者： G. Aggarwal A. Gaur d. k. srivastava department of Biotechnology Dr. Yashwant Singh Parmar University of Horticulture and Forestry NauniSolan 173230 HP India department of Food Technology Desh Bhagat UniversityMandi Gobindgarh 147301 Pb India

Populus species are important resources for industry and in scientific study on biological and agricul- tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar （Populus ciliata wall. ex Royle）. The effect of TdZ alone and in combi- nation with adenine and NAA was studied on the regen- eration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glass- houses. After surface sterilization the explants were cul- tured on shoot induction medium. High percentage shoot regeneration （86 %） was recorded on MS medium sup- plemented with 0.004 mg L-1 TdZ and 79.7 mg L-1 adenine. The regenerated shoots for elongation and multi- plication were transferred to MS ＋ 0.5 mg L-1 BAP ＋ 0.2 mg L-1 IAA ＋ 0.3 mg L-1 GA3. Root re- generation from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L-1 IBA. Hi- malayan poplar plantlets could be produced within 2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.

关键词： In vitro regeneration Petiole explants Growth regulator Thidiazuron Populus ciliata

Ce-Co-doped BiFeO_3 multiferroic for optoelectronic and photovoltaic applications

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Chinese Physics B 2017年第11期26卷 383-388页

作者： Jyoti Sharma deepak Basandrai A k srivastava department of Physics Lovely Professional University

The Ce-Co-doped BiFeO3 multiferroic, Bi（1-x）Ce）xFe（1-x）CoxO3（x = 0.00, 0.01, 0.03, and 0.05）, has been prepared by a sol-gel auto-combustion method and analyzed through Raman spectroscopy, photoluminescence, and UV-visible spectroscopy. We have observed an anomalous intensity of the second-order Raman mode at - 1260 cm^-1 in pure BFO and suppressed intensity in doped samples, which indicates the presence of spin two-phonon coupling in these *** photoluminescence spectra show reduction in the intensity of emission with the increasing dopant concentration, which indicates the high charge separation efficiency. A sharp absorption with three charge transfer（C-T） and two d-d transitions are shown by UV-visible spectra in the visible region. The band gap of BiFeO3（BFO） is decreasing with increasing dopant concentrations and the materials are suitable for photovoltaic applications.

关键词： Raman and UV-visible spectroscopy photoluminescence and photo-voltaic applications

Effect of hydrogen plasma treatment on the growth and microstructures of multiwalled carbon nanotubes

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Nano-Micro Letters 2010年第1期2卷 42-48页

作者： S.k.srivastava V.d.Vankar V.kumar department of Physics Indian Institute of Technology Delhi National Physical Laboratory Dr.K.S.Krishnan Marg

The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been *** plasma was characterized in-situ using optical emission *** of the films was examined by scanning electron *** analysis was carried out by high resolution transmission electron microscopy(HRTEM)equipped with energy dispersive X-ray spectroscopy(EdS)and micro-diffraction *** is found that oxide films without H_2 plasma pretreatment or treated for lesser time resulted in CNT films with high percentage of carbonaceous particles and with embedded particles/nanorods distributed discontinuously in the cavity of the *** embedded particles were found to be of iron carbide(Fe-C)as confirmed by HRTEM,EdS and micro-diffraction *** observations suggested that the iron oxide particles had poor catalytic action for CNT growth and in-situ reduction of oxide clusters to Fe by hydrogen plasma plays a key role in discontinuous filling of the nanotubes by the catalytic particles.

关键词： Carbon nanotubes Chemical vapor deposition Iron carbide MPECVd

Radiation Losses in the Microwave X Band in Al-Cr Substituted Y-Type Hexaferrites

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Chinese Physics Letters 2017年第4期34卷 35-38页

作者： d.Basandrai R.k.Bedi A.dhami J.Sharma S.B.Narang k.Pubby A.k.srivastava Research Scholar Department of Physics I. K. Gujral Punjab Technical University Jalandhar India department of Physics Lovely Professional University Phagwara India principal Satyam Institute of Engineering & Technology Amritsar India department of Electronic Technology Guru Nanak Dev University Amritsar India

We present a study on radiation losses in the microwave X band in Al-Cr substituted Y-type hexaferrites, namely Ba2Mg2Alx/2Crx/2Fe12-xO22 （x = 0, 0.5 and 1.0）. The study is performed by means of a vector network analyzer, Fourier transform infrared spectroscopy, a vibrating sample magnetometer and x-ray powder diffraction. Ba2Mg2Fe12O22 hexaferrite shows radiation loss of -37.25dB （99.999% loss） at frequency 9.81 GHz, which can be attributed to its high value of saturation magnetization, i.e., 22.08emu/g. Moreover, we obtain that magnetic properties have strong influence on the radiation losses.

关键词： Ba Al Radiation Losses in the Microwave X Band in Al-Cr Substituted Y-Type Hexaferrites Cr

Optical properties of amorphous thin film of Se-Te-Ag system prepared by using thermal evaporation technique

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Progress in Natural Science:Materials International 2011年第1期21卷 36-39页

作者： Madhu MISHRA Rashmi CHAUHAN Anju kATIYAR k.k.srivastava department of Physics Dayanand Braiendra Swarup D.B.S.(P.G.) CollegeKanpur(U.P.)India department of Physics D.A-V.(P.G.) CollegeKanpur(U.P.)India department of Physics Dayanand Brajendra Swarup D.B.S.(P.G.) CollegeKanpur(U.P.)India

Optical reflection and transmission spectra of Se80-xTe20Agx(where x=0,5,10 and 15,molar percent) chalcogenide thin films have been obtained in the range 300-1 200 nm at room *** samples are prepared by melt quenching technique and thin films are obtained by using vacuum evaporation technique on glass transition at room *** present paper reports the effect of Ag contents on various optical parameters such as optical band gap,refractive index,extinction coefficient,absorption *** spectra are used for calculating these optical *** band gap Egis determined from the plot of (ahv)1/2versus *** and imaginary parts of the dielectric constant changes slightly with the variation of Ag contents in different *** film exhibits indirect band gap which increases with increasing Ag *** observed behavior is explained on the basis of davis and Mott model for the density of *** absorption coefficient of thin films exhibits linear dependence on photon *** optical parameters are calculated by using theory of *** the optical parameters change with the variation of the film *** spectrophotometer JASCO-UV/VIS/NIR is used to determine optical constants.

关键词： chalcogenide thin film band gap optical constant