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Localization of polycyclic aromatic hydrocarbons and heavy metals in surface soil of Asia’s oldest oil and gas drilling site in Assam,northeast India:Implications for the bio-economy

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Emerging Contaminants 2016年第3期2卷 119-127页

作者： Hemen Sarma n.F.Islam P.Borgohain A.Sarma M.n.V.prasad Department of Botany N N Saikia CollegeTitabarAssamIndia Department of Biotechnology Pandu CollegeGuwahatiAssamIndia Department of Plant Science University of HyderabadHyderabadTelanganaIndia

The environmental influx of hazardous contaminants viz PAHs and HMs occurs due to oil and gas drilling,and processing of petroleum products in industrial facilities and *** problem plagues crude oil drilling sites as PAHs are an essential component of and HMs coexist with crude *** analyzed the spatial distribution of 16 PAHs and 8 HMs in 10 contaminated sites of Assam,a state in *** included Digboi,where crude oil was drilled in 1867 and the first oil well in Asia that was ***Ʃ16 PAHs in soil were detected with a minimum of 13.48 and a maximum of 86.3 mgkg1 andƩ8 heavy metal concentrations in the soil ranged between 69.51 and 336.06 mgkg1.A negative correlation was detected between the relative concentrations of PAHs and *** results confirmed that the nonbiodegradable nature of HMs made them stay in the soil for longer periods of *** our study,we found that the levels of lead,copper,nickel,and chromium(total)in soil were 73.62,11.86,58.97 and 158.66 mgkg*** recovery percentage for PAHs and HMs were in the range of 67e97%and 90e95%*** distribution indices for Phenanthrene/Anthracene,naphthalene/Acenapthhylene,chyrsene/Benzo(g,h,i)perylene and Fluranthene/Pyrene)calculated for soil samples indicated that the spatial distribution of PAHs in soil is uneven which might be due to variations in contaminates disseminated in *** regionalized concentration has serious implications on the bio-economy both in terms of health and economy,especially since the proximity of crude oil sites to paddy fields and/or tea plantations uniquely marks the landscape of upper Assam.

关键词： PAH Heavy metals Spatial distribution indices Oil Drilling site

BE-SOnOS flash memory along with metal gate and high-k dielectrics in tunnel barrier and its impact on charge retention dynamics

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Journal of Semiconductors 2016年第3期37卷 42-47页

作者： Sonal Jain Deepika Gupta Vaibhav neema santosh Vishwakarma IET-Devi Ahilya University Indore MP India IIT Indore MP India

We investigate the effect of a high-k dielectric in the tunnel layer to improve the erase speed-retention trade-off. Here, the proposed stack in the tunnel layer is AlLaO_3/Hf AlO/SiO_2. These proposed materials possess low valence band offset with high permittivity to improve both the erase speed and retention time in barrier engineered silicon-oxide-nitride-oxide-silicon（BE-SOnOS）. In the proposed structure Hf Al O and AlLaO_3 replace Si_3n_4 and the top SiO_2 layer in a conventional oxide/nitride/oxide（OnO） tunnel stack. Due to the lower conduction band offset（CBO） and high permittivity of the proposed material in the tunnel layer, it offers better program/erase（P/E） speed and retention time. In this work the gate length is also scaled down from 220 to 55 nm to observe the effect of high-k materials while scaling, for the same equivalent oxide thickness（EOT）. We found that the scaling down of the gate length has a negligible impact on the memory window of the devices. Hence, various investigated tunnel oxide stacks possess a good memory window with a charge retained up to 87.4%（at room temperature） after a period of ten years. We also examine the use of a metal gate instead of a polysilicon gate, which shows improved P/E speed and retention time.

关键词： high-k dielectric materials nonvolatile memory tunnel barrier retention endurance and bandgapengineered

Mapping rice-fallow cropland areas for short-season grain legumes intensification in South Asia using MODIS 250 m time-series data

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International Journal of Digital Earth 2016年第10期9卷 981-1003页

作者： Murali Krishna Gumma prasad S.Thenkabail Pardharsadhi Teluguntla Mahesh n.Rao Irshad A.Mohammed Anthony M.Whitbread International Crops Research Institute for the Semi-Arid Tropics PatancheruIndia U.S.Geological Survey(USGS) Western Geographic Science CenterFlagstaffAZUSA Humboldt State University ArcataCAUSA

The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia,using MODIS 250 m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow ***-fallow cropland areas are those areas where rice is grown during the kharif growing season(June–October),followed by a fallow during the rabi season(november–February).These cropland areas are not suitable for growing rabi-season rice due to their high water needs,but are suitable for a short-season(≤3 months),low water-consuming grain legumes such as chickpea(Cicer arietinum L.),black gram,green gram,and ***(double-cropping)in this manner can improve smallholder farmer’s incomes and soil health via rich.nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand *** grain legumes,primarily chickpea,are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the *** suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers:(a)rice crop is grown during the primary(kharif)crop growing season or during the north-west monsoon season(June–October);(b)same croplands are left fallow during the second(rabi)season or during the south-east monsoon season(november–February);and(c)ability to support low water-consuming,short-growing season(≤3 months)grain legumes(chickpea,black gram,green gram,and lentils)during rabi *** irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season,because the moisture/water demand of these crops is too *** study established cropland classes based on the every 16-day 25

关键词： Croplands cropland fallow seasonal rice mapping rice-fallow intensification kharif rabi remote sensing double-cropping MODIS 250 m nDVI spectral match.ng techniques ground survey data grain legumes potential cropland areas South Asia

Flux blended synthesis of novel Y2O3：Eu^3＋ sensing arrays for highly sensitive dual mode detection of LFPs on versatile surfaces

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Journal of Rare Earths 2018年第9期36卷 954-964页

作者： K.n. Venkatachalaiah H. nagabhushana R.B. Basavaj G.R Darshan B. Daruka prasad S.C. Sharma Department of Physics Amrito School of Engineering Amrito Vishwa Vidyapeethom Amrita University Bengoluru 560035 India Research and Development Center Bharathiar University Coimbatore 641046 India Prof. C.n.R. Rao Centre for Advanced Material Science Tumakuru University Tumakuru 572103 India Department of Physics Acharya Institute of Graduate Studies Bangalore 560107 India Department of Physics B.M.S. Institute of Technology and Management Visveswaraya Technological University affiliated Bangalore 560064 India Honorary Professor Department of Mechanical Engineering Jain University Advisor Jain Croup of Institutions Bangalore 560069 India

In the present communication,various fluxes blended Y2 O3：Eu3＋（5 mol%） nanopowders（nPs） were successfully fabricated by solution combustion *** pattern confirms body-centered cubic structure of the prepared *** band gap（Eg） of the fabricated products was estimated and is found to be in the range of 3.13-3.32 ***（PL） emission spectra exhibit sharp and intense peaks at ～579,592,614,657,704 nm corresponding to 5 D0→7 FJ（J = 0,1,2,3 and 4） transitions of Eu3＋ *** of fluxes for enhancing the PL emissions was extensively *** studies of the prepared samples are located in pure red *** nPs were explored as a novel sensing agent for visualization of latent fingerprints（LFPs） on various surfaces including porous,semiporous and non-porous surfaces followed by powder dusting *** experiments including aging,temperature,scratch.ng and aquatic fresh water treatment tests were performed to evaluate applicability of the fabricated *** LFPs exhibit well defined ridge details including most authenticated sweat pores are also revealed with high sensitivity,selectivity,little background hindrance and less *** results evidence that the method and fabricated nPs can be considered to be simple,rapid and economical and provide novel sensing platform for LFPs visualization in prospective forensic applications.

关键词： Fluxes Photoluminescence Latent fingerprint Sweat pores Forensic applications Rare earths

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

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ch.nese 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

The giant tin polymetallic mineralization in southwest ch.na:Integrated geochemical and isotopic constraints and implications for Cretaceous tectonomagmatic event

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Geoscience Frontiers 2020年第5期11卷 1593-1608页

作者： Yanbin Liu Lifei Zhang Xuanxue Mo M.santosh Guoch.n Dong Hongying Zhou MOE Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China State Key Laboratory of Geological Processes and Mineral Resources And School of Earth Science and ResourcesChina University of Geosciences(Beijing)Beijing 100083China Department of Earth Sciences University of AdelaideSA5005Australia Tianjin Institute of Geology and Mineral Resources China Geological SurveyTianjin 300170China

The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South *** polymetallic mineralization in this belt includes the niusipo,Malage,Songshujiao,Laoch.ng and Kafang ore fields in the Gejiu area which are spatially and temporally associated with the Kafang-Laoch.ng and Songshujiao granite *** granites are characterized by variable A/CnK values(mostly>1.1,except for two samples with 1.09),high contents of SiO2(74.38-76.84 wt.%)and Al2 O3(12.46-14.05 wt.%)and variable CaO/na2 O ratios(0.2-0.65)as well as high zirconδ18O values(7.74‰-9.86‰),indicative of S-type *** rocks are depleted in Rb,Th,U,Ti,LREE[(La/Yb)n=1.4-20.51],Ba,nb,Sr,and Ti and display strong negative Eu and Ba *** rocks possess high Rb/Sr and Rb/Ba ratios,relatively low initial 87Sr/86Sr ratios(0.6917-0.7101),and less radiogenicεnd(t)values(-8.0 to-9.1).The zircon grains from these rocks show negativeεHf(t)values in the range of-3.7 to-9.9 with mean TDM2(nd)and TDM2(Hf)values of 1.57 Ga and 1.55 *** show initial 207Pb/204Pb ranging from15.69 to 15.71 and 206Pb/204Pb from 18.36 to *** from Songshujiao granites exhibits higher U and lower Th/U ratios,lowerδ18O values and higherεHf(t)values than those of the zircon grains in the KafangLaoch.ng *** geochemical and isotopic features indicate that the Laoch.ng-Kafang granites originated by partial melting of Mesoproterozoic crustal components including biotite-rich metapelite and metagraywacke,whereas the Songshujiao granites were derived from Mesoproterozoic muscovite-rich metapelite crustal *** zircon grains from the Songshujiao,Laoch.ng and Kafang granites have high-U concentrations and their SIMS U-Pb ages show age scatter from 81.6 Ma to 88.6 Ma,80.7 Ma to 86.1 Ma and 82.3 Ma to 87.0 Ma,suggesting formation earlier than the monazite and *** SIMS U-Pb ages and Th-Pb ag

关键词： S-type granite SIMS monazite and zircon geochronology Cassiterite U–Pb age Zircon Hf–O isotope Sr–nd–Pb isotope Yangtze Block

Water‑Dispersible CsPbBr_(3) Perovskite nanocrystals with Ultra‑Stability and its Application in Electrochemical CO_(2) Reduction

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nano-Micro Letters 2021年第11期13卷 190-202页

作者： Keqiang ch.n Kun Qi Tong Zhou Tingqiang Yang Yupeng Zhang Zhinan Guo ch.ng‑Keun Lim Jiayong Zhang Igor Zutic Han Zhang Paras n.prasad Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060People’s Republic of China Institute for Lasers Photonicsand BiophotonicsDepartment of ChemistryUniversity at BuffaloState University of New YorkBuffaloNY 14260USA Department of Physics University at BuffaloState University of New YorkBuffaloNY 14260USA Department of chemical and Materials Engineering School of EngineeringNazarbayev UniversityNur‑Sultan City 010000Kazakhstan Jiangsu Key Laboratory of Micro and nano Heat Fluid Flow Technology and Energy Application School of Physical Science and TechnologySuzhou University of Science and TechnologySuzhouJiangsu 215009People’s Republic of China

Thanks to the excellent optoelectronic properties,lead halide perovskites(LHPs)have been widely employed in highperformance optoelectronic devices such as solar cells and lightemitting ***,overcoming their poor stability against water has been one of the biggest challenges for most ***,we report a novel hot-injection method in a Pb-poor environment combined with a well-designed purification process to synthesize water-dispersible CsPbBr_(3) nanocrystals(nCs).The as-prepared nCs sustain their superior photoluminescence(91%quantum yield in water)for more than 200 days in an aqueous environment,which is attributed to a passivation effect induced by excess CsBr *** to the ultra-stability of these LHP nCs,for the first time,we report a new application of LHP nCs,in which they are applied to electrocatalysis of CO_(2) reduction ***,they show significant electrocatalytic activity(faradaic yield:32%for ch4,40%for CO)and operation stability(>350 h).

关键词： CsPbBr_(3)nanocrystals Water-dispersible Ultra-stability Electrochemical CO_(2)reduction

A new High Performance Realization of Hyperchaotic Modified Canonical chua Circuit Using JFETs

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ch.nese Physics Letters 2008年第8期25卷 2803-2805页

作者： Prem Bhushan Mital Umesh Kumar R.S. prasad IEC College of Engineering and Technology GB Nagar Pin-201 306 India Indian Institute of Technology Delhi Pin-110016 India Inderprastha Eng. College Sahibabad Ghaziabad (UP) India

A new implementation of hyperchaotic modified canonical chua circuit using junction field-effect transistors （JFETs） is proposed. The design is based on a source coupled JFET circuit to approximate a smooth cubic nonlinearity and a two-terminal negative resistance element containing a p-n-p silicon transistor and an n-ch.nnel JFET. The realization is supported by Orcad Pspice simulation and numerical MATLAB results. The hyperchaotic nature is confirmed by two positive Lyapunov exponents associated with the attractor which is a fractal with a Lyapunov dimension between 3 and 4.

关键词： OSCILLATOR

Load-dependent indentation behavior ofβ-SiAlOn andα-silicon carbide

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Journal of Advanced Ceramics 2013年第2期2卷 185-192页

作者： Prasenjit BARICK Dulal ch.ndra JAnA Bhaskar prasad sahA Centre for non-Oxide Ceramics International Advanced Research Centre for Powder Metallurgy and New MaterialsPO:BalapurRCI RoadHyderabad 500005Andhra PradeshIndia

A comparative study was carried out on the load-dependent indentation behavior with respect to hardness and induced cracks ofβ-SiAlOn andα-silicon carbide *** is observed that silicon carbide(SiC)exhibits lower transition load,early cracking and severely crushed indentation sites,whereasβ-SiAlOn shows higher transition load and damage-free indentation zone even at the maximum applied load(294.19 n).Crack density is higher forα-SiC with comparison toβ-SiAlOn at each *** exhibits both main and secondary radial types of cracking from low indentation load(0.98 n).Cracks are often associated with branch.ng at higher load(>9.80 n)forα-SiC.β-SiAlOn exhibits cracks which are mainly radial types initiated at 4.90 n *** opposing behaviors ofβ-SiAlOn andα-SiC are attributed to their difference in hardness,toughness,and brittleness *** brittleness ofα-SiC results in early and severe cracking around its indentations.β-SiAlOn shows less cracking due to its lower brittleness and higher *** increased size of indentation-induced cracks ofα-SiC is higher than that ofβ-SiAlOn due to the rapid crack propagation inα-SiC with transgranular fracture behavior.

关键词： SiAlOn silicon carbide(SiC) indentation hardness crack