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risk assessment of heavy metal contaminated soil in the vicinity of a lead/zinc mine

Journal of Environmental Sciences 2005年第6期17卷 881-885页

作者： LI Jing XIE Zheng-miao ZHU Yong-guan ravi Naidu Institute for Soil and Water resources and Environment Zhejiang University Hangzhou 310029 China research Centre for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Centre for Environmental risk Assessment and remediation University of South Australia Mawson Lakes SA 5095 Australia

Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemical species and availability of lead, zinc, cadmium and copper in nine surface（0 to 20 cm） soils from near an abandoned lead/zinc mine tailings located in Shaoxing, Zhejiang, China. Total heavy metal contents ranged from 5271 to 16369 mg/kg for Pb, 387 to 1221 mg/kg for Zn, 3.0 to 9.3 mg/kg for Cd and 65 to 206 mg/kg for Cu. In general, all heavy metals exceeded China National Standards for Soil Environmental Quality of Heavy Metals by a factor of 3-65 times. Comparison of the heavy metal concentrations（Pb, Zn, Cd and Cu） with clay content revealed a strongly significant relationship while significant relationship（ P 〈 0.001 ） was also obtained between Cd ＋ Zn and Pb ＋ Cu. Solid phase speciation of the soils using Tessier procedure showed that the heavy metals were distributed in the order： residual 〉〉 organically complexed-Fe-Mn oxides occluded 〉 carbonate bound 〉 exchangeable 〉 water soluble. In the organic matter fraction, the ratio of Pb（29.1% ） to its total concentration in the soils was higher than those of Zn（4.70% ）, Cd（3.16% ） and Cu（9.50% ）. The percentages of the water soluble and the exchangeable fractions of Pb（1.80% ） and Cd（2.74% ） were markedly greater than those of Zn（0.10% ） and Cu（0.15% ）, suggesting that Pb and Cd are relatively more mobile and hence more toxic in the contaminated soils. Strongly significant relationships between H20-Pb, H20-Zn and H20-Cu, strong positive correlations between H20-Pb, H20-Zn, H20-Cu and organic matter in soil were found. The content of H20-Pb, H20-Zn, H20-Cu was negatively correlated with pH values. The similar negative relationships between pH values and exchangeable heavy metals were also recorded. It is suggested that increasing soil pH or liming the soil could decrease bioavailability of heavy met

关键词： fractionation heavy metal mining tailings risk assessment soil pollution

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PULPING STUDIES OF WHEAT STrAW USING SODA AND SODA -ANTHrAQUINONE PrOCESSES

PULPING STUDIES OF WHEAT STRAW USING SODA AND SODA -ANTHRAQU...

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1988国际非木材纤维制浆造纸会议

作者： ravi MOHAN r.PrASAD r.YADAV A.k.rAY Institute of Paper Technology Saharanpur-247001 INDIA Institute of Paper Technology Saharanpur-247001 INDIA Institute of Paper Technology Saharanpur-247001 INDIA Institute of Paper Technology Saharanpur-247001 INDIA

＜正＞Soda-Anthraquinone process,a non-sulphur pulping process of fibrous materials,involves soda cooking in presence of small amount of Anthraquinone or its derivatives. This results in improved yield with less rejects without affecting any quality of *** though the effect of Anthraquinone on pulping of hard and softwood are extensively reported in literature, the information on non-woody fibres,specially for Wheat straw are extremely limited. As Wheat straw is now increasingly used in. Indian mills,it will be of immense potential to elucidate the optimal parameters in pulping of Wheat straw from operational point of these *** no correlations are available between input and output variables or kinetics of soda/soda-Anthraquinone pulping of Wheat straw. An attempt has been made in this present investigation to identify the effect of different pulping parameters on the degree of cooking of Wheat straw experimentally in the laboratory. The range of all possible input and output variables are examined in the light of normal industrial operation in terms of delignification. Based on the data Important kinetic parameters such as H-factor,specific reaction rate,and activation energy are evaluated for both soda and soda-Anthraquinone pulping *** pulp properties like screened yield, rejects,residual lignin,fibre fractionation,unbleached pulp-strength properties are also evaluated From detailed experimental studies,the main conclusions can be drawn as follows: The addition of Anthraquinone brings about 4-5 percent increase in yield,a significant decrease of kappa number and lignin . content of pulp but no appreciable change in pentosan content. 10-13 percent active alkali might be taken as optimum for wheat straw *** optimum time and temperature at the bulk delignification stage for straw pulping are found to be 2 hours and 393k.respectively with approximately 88 percent delignification. 423k with 1 hour cooking time can also be proper operationa

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Differential gene expression profile evaluation between uterine leiomyoma and leiomyosarcoma using a machine learning approach

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Gynecology and Obstetrics Clinical Medicine 2023年第3期3卷 154-162页

作者： Sonal Upadhyay ravi Bhushan Anima Tripathi Lavina Chaubey Amita Diwak.r Pawan k.Dubey Centre for Genetic Disorders Institute of ScienceBanaras Hindu UniversityVaranasi221005Uttar PradeshIndia Department of Zoology MMVBanaras Hindu UniversityVaranasi221005Uttar PradeshIndia Department of Obstetrics and Gynecology Institute of Medical ScienceBanaras Hindu UniversityVaranasi221005Uttar PradeshIndia

Objective The objective of this study is to differentiate between uterine leiomyomas(ULM)and uterine leiomyosarcomas(ULMS)by conducting molecular differential analysis and identifying potential prognostic biomark.rs for *** The microarray datasets(GSEID:GSE64763 and GSE185543)were retrieved from the Gene Expression Omnibus *** preprocessing and differential gene expressions(DEGs)analysis were *** DEGs were further intersected to find the common DEGs in ULM and ULMS and further validation of selected DEGs were ***,a machine learning classifier was also applied in the selection of ***-protein interaction network based upon STrING v 10.5,was ***,Gene Ontology(GO)and kEGG(kyoto Encyclopedia of Genes and Genomes)pathway enrichment analyses were also performed to dissect possible functions and *** A total of 50 significant DEGs for ULM while 321 DEGs for ULMS have been identified with their official gene *** ULM and ULMS,a total of 14 common DEGs were identified of which 8 were up-regulated while 6 were *** DEGs of(GSE185543)were also analyzed and the significant genes were retrieved common in both datasets for further *** a machine learning approach,10 feature genes were *** the expression profiles of these genes,a sequential minimal optimization(SMO)prediction model was built on the training set,and it accurately and reliably classified features expression in ULM and ULMS in the independent test ***,Co-Enrichment analysis was also *** The study identified several DEGs,including ZNF365,EPYC,COL11A1,SHOX2,MMP13,TNN,GPM6A,and GATA2,through cross-validation,machine learning classifier,and Co-Enrichment *** candidate disease genes may provide valuable insight into the underlying mechanisms and could be used as potential diagnostic biomark.rs for ULM and ***,further validation of the

关键词： sarcoma approach symbol

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An Upper and Lower Solution Theory for the Problem(G′(y))′+f(t,y)=0 on Finite and Infinite Intervals

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Acta Mathematica Sinica,English Series 2006年第3期22卷 827-832页

作者： ravi P.AGArWAL Donal O'rEGAN Svatoslav STANEk Department of Mathematical Sciences Florida Institute of TechnologyMelbourneFlorida 32901-6975USA Department of Mathematics National University of IrelandGalwayIreland Department of Mathematical Analysis Faculty of SciencePalack University

A new upper and lower solution theory is presented for the second order problem （G＇（y））＇＋ f（t, y） = 0 on finite and infinite intervals. The theory on finite intervals is based on a Leray-Schauder alternative,... 详细信息

关键词： alternative upper and lower solutions infinite interval diagonalization process Leray-Schauder alternative

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Existence of Solutions to Nonlinear Neumann Boundary Value Problems with p-Laplacian Operator and Iterative Construction

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 463-470页

作者： Li Wei Hai-yun Zhou ravi P. Agarwal School of Mathematics and Statistics Hebei University of Economics and Business Shijiazhuang 050061 China Institute of Applied Mathematics Ordnance Engineering College Shijiazhuang 050003 China Department of Mathematical Sciences Florida Institute of Technology Melbourne FL 32901 U.S.A.

By using some results of pseudo-monotone operator, we discuss the existence and uniqueness of the solution of one kind nonlinear Neumann boundary value problems involving the p-Laplacian operator. We also construct an... 详细信息

关键词： maximal monotone operator pseudo-monotone operator p-Laplacian operator iterative scheme

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Journal of Ocean Engineering and Science 2023年第2期8卷 111-123页

作者： raj kumar ravi Shank.r Verma Atul kumar Tiwari Department of Mathematics Faculty of Engineering&TechnologyVeer Bahadur Singh Purvanchal UniversityJaunpur222003India Department of Mathematics Motihari College of EngineeringMotihari845401BiharIndia

This work is devoted to get a new family of analytical solutions of the(2+1)-coupled dispersive long wave equations propagating in an infinitely long channel with constant depth,and can be observed in an open sea or in wide *** solutions are obtained by using the invariance property of the similarity transformations method via one-parameter Lie group *** repeated use of the similarity transformations method can transform the system of PDEs into system of *** adequate restrictions,the reduced system of ODEs is *** simulation is performed to describe the solutions in a physically meaningful *** profiles of the solutions are simulated by taking an appropriate choice of functions and constants involved *** each animation,a frame for dominated behavior is *** exhibit elastic multisolitons,single soliton,doubly solitons,stationary,kink and parabolic *** results are significant since these have confirmed some of the established results of *** et al.(2020)and *** et al.(2020).Some of their solutions can be deduced from the results derived in this *** results in the existing literature are different from those in this work.

关键词： Dispersive long wave equations Solitons Invariants Lie-group Similarity solutions

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Carbon Materials in Perovskite Solar Cells: Prospects and Future Challenges

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Energy & Environmental Materials 2019年第2期2卷 107-118页

作者： Victoria Ferguson S.ravi P.Silva Wei Zhang Advanced Technology Institute(ATI) University of SurreyGU27XHUK

Metal halide perovskite solar cells are emerging candidates for nextgeneration thin-film photovoltaic devices with the potential for extremely low fabrication cost and high power conversion *** solar cells have demonstrated a rapid development in device performance over the last decade,from an initial 3.81%to a most recently certified 24.2%,though the challenges of long-term stability and lead toxicity still *** materials,ranging from zero-dimensional carbon quantum dots to threedimensional carbon black materials,are promising candidates for the enhancement of both efficiency and stability of perovskite solar cells,offering unique advantages for incorporation into various device *** this review article,we present a concise overview of important and exciting advancements of perovskite solar cells that incorporate different dimensions of carbon material in their device architectures in an effort to simultaneously improve device performance and long-term *** also discuss the major advantages and potential challenges of each technique that has been developed in the most recent ***,we outline the future opportunities toward more efficient and stable perovskite solar cells utilizing carbon materials.

关键词： carbon materials long-term stability metal halide perovskite photovoltaics

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EXISTENCE AND UNIQUENESS OF NON-TrIVIAL SOLUTION OF PArABOLIC p-LAPLACIAN-LIkE DIFFErENTIAL EQUATION WITH MIXED BOUNDArIES

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Acta Mathematica Scientia 2016年第6期36卷 1780-1792页

作者：魏利陈蕊 ravi P.AGArWAL Patricia YJ WONG School of Mathematics and Statistics Hebei University of Economics and Business Department of Mathematics Texas A&M University-Kingsville Department of Mathematics Faculty of ScienceKing Abdulaziz University School of Electrical and Electronic Engineering Nanyang Technological University

One parabolic p-Laplacian-like differential equation with mixed boundaries is au/at in the corresponding studies is replaced by a（au/at）, studied in this paper, where the item au/at which makes it more general. The sufficient condition of the existence and uniqueness of non-trivial solution in L2（O, T; L2 （Ω）） is presented by employing the techniques of splitting the boundary problems into operator equation. Compared to the corresponding work, the restrictions imposed on the equation are weaken and the proof technique is simplified. It can be regarded as the extension and complement of the previous work.

关键词： maximal monotone operator Caratheodory'conditions subdifferential p-Laplacian-tike equation nontrivial solution

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In-situ probing of thermal desorption of vapor molecules on a nanowire via work function variance

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Nano research 2016年第11期9卷 3334-3345页

作者： kovur Prashanthi John Eric Hawk.ryan McGee ravi Gaikwad Thomas Thundat Ingenuity Lab Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2V4 Canada

Nanowire sensors based on variations of their electrical properties show great potential for real-time, in situ monitoring of molecular adsorption and desorption. Although the molecular adsorption-induced change in the electronic work function is very sensitive, it does not have any specificity. However, the temperature dependency of the adsorption-induced work function variation can provide limited selectivity based on the desorption temperature. In this study, we report the in situ probing of molecular desorption by monitoring the work function variations of a single Pt nanowire as a function of temperature. The work function of a clean Pt nanowire shows a significant variation due to vapor adsorption at room temperature. Increasing the temperature of the nanowire results in a variation of the work function due to molecular desorption. Experimentally measured differential work function as a function of temperature shows desorption peaks at 36 and 44 ℃ for methanol and ethanol molecules respectively. Adsorption-induced variation of the Pt nanowire work function was further confirmed using ultraviolet photoelectron spectroscopy before and after exposure to methanol vapor. These results show that the molecular adsorption/desorption-induced variation of the work function and its temperature dependency can be used for developing nanoscale electro-calorimetric sensors.

关键词： kelvin probe microscopy nanowires thermal desorption work function

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Meeting employees where they are:The rise of workplace mental health services

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World Journal of Psychiatry 2022年第8期12卷 1002-1003页

作者： Gaddy Noy ravi Navin Shah Department of Psychiatry Columbia University Medical CenterNew YorkNY 10032United States

Many key organizations have called attention to the importance of addressing workplace mental *** this Open Forum piece,two academic psychiatrists present recommendations from their experiences providing psychiatric care in a corporate setting.A literature review using the PubMed database was *** search found no peer review articles that discuss the topic of employersponsored mental health services outside of traditional employee assistant *** on first-hand experience,the authors of this forum describe key issues and best practices to ensure employer-sponsored mental health services are a successful treatment for patients and mental health providers alike.

关键词： Employer sponsored mental health Employee mental health Psychiatry Corporate wellness Workplace mental health Mental health

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