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Environmental factors regulating cyanobacteria dominance and microcystin production in a subtropical lake within the Taihu watershed,China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第4期13卷 311-322页

作者： Wan-min NI Jian-ying ZHANG Teng-da DING r.Jan STEVENSON Yin-mei ZHU Institute of Environmental Science Zhejiang University Hangzhou 310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Hangzhou 310058China Center for Water Sciences Michigan State UniversityEast LansingM148824.USA

Understanding the pattern ofphytoplankton and their dependence on water quality variables, can help the management of eutrophic lakes. The aim of this study was to determine water quality and environmental factors associated with cyanobacteria dominance and microcystin production in Qingshan Lake, a subtropical lake located in the headwater of the Taihu watershed, China. Water samples collected monthly from 10 study sites in Qingshan Lake were analyzed for the species distributions of freshwater algae and physico-chemical parameters including total nitrogen （TN）, ammonia （NH4＋-N）, nitrate （NO3--N）, total phosphorus （TP）, and chlorophyll a （Chl-a） from June, 2008 to May, 2009. Qingshan Lake was found to be eutrophic, based on the calculated trophic state index （TSI）. The average TN of 4.33 mg/L during the study period exceeded the Surface Water Quality Standards of China. TP was significantly correlated with relative abundance of cyanobacteria and Microeystis biovolume, indi- cating its important role in regulating cyanobacteria. Microcystis, Anabaena, and Oscillatoria were dominant cyanobacteria in Qingshan Lake from June to November, 2008. Cyanobacteria dominance was regulated by water temperature and TE Principal component analysis further indicated that microcystin production was most affected by water temperature, TP, and cyanobacteria biomass. results suggest that the control of TP in summer can mitigate cyanobacteria dominance and microcystin production in Qingshan Lake, and close monitoring should be undertaken in summer.

关键词： cyanobacteria Microcystins Eutrophication Water quality Taihu watershed

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Influence of Sputtering Gas on Morphological and Optical Properties of Magnesium Films

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Journal of Materials Science & Technology 2011年第1期27卷 51-58页

作者： Yogendra K.Gautam Amit K.Chawla Vipin Chawla r.D.Agrawal ramesh Chandra Department of Metallurgical and Materials Engineering Indian Institute of Technology Roorkee Nano Science Laboratory Institute Instrumentation CentreIndian Institute of Technology Roorkee

The influence of sputtering gas（He Ar） on the structural properties of Mg thin films has been *** optical property（reflectance） that results from the growth of films at varying substrate temperatures（Tsub） was also *** deposited films were characterized by using X-ray diffraction（XrD）,field emission scaning electron microscopy（FE-SEM）,atomic force microscopy（AFM） and UV-Vis-NIr *** smaller crystallite size and lower deposition rate were observed in the presence of Helium atmosphere compared to *** of the films shows 2D hexagonal geometry of grains in the deposition temperature range（Tsub≈50-150℃） in both the sputtering *** surface roughness of the polycrystalline films were found to increase with increase in the deposition temperature of both ambient *** reflectance of Mg films was measured in near infrared region and larger reflectance was observed from Mg films sputtered in He atmosphere compared to that in argon.

关键词： X-ray diffraction(XrD) Atomic force microscopy(AFM) reflectance Mg films Microstructure

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MODIFICATION OF SODIUM SALT OF PArTIALLY CArBOXYMETHYLATED TAMArIND KErNEL POWDEr THrOUGH GrAFTING WITH ACrYLONITrILE: SYNTHESIS, CHArACTErIZATION AND SWELLING BEHAVIOr

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Chinese Journal of Polymer Science 2013年第12期31卷 1670-1684页

作者： J.H.Trivedi J.r.Jivani K.H.Patel H.C.Trivedi P.G.Dept.of Chemistry Sardar Patel UniversityVallabh Vidyanagar Amneal Phamaceuticals

A graft copolymer of polyacrylonitrile （PAN） with sodium salt of partially carboxymethylated tamarind kernel powder （Na-PCMTKP, DS ^-= 0.15） was synthesized by using ceric ammonium nitrate （CAN） as a redox initiator in an aqueous medium. The optimum reaction conditions for affording maximum percentage of grafting were established by successively varying reaction conditions such as concentrations of nitric acid, CAN, monomer （AN） as well as reaction time, temperature and amount of substrate. The influence of these reaction conditions on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer （Na-PCMTKP-g-PAN, percentage of grafting G = 413.76% and percentage of grafting efficiency GE = 96.48%） sample synthesized under the established optimized reaction conditions was hydrolyzed by 0.7 mol-L l NaOH solution at 90-95 ℃ to yield the superabsorbent hydrogel, H-Na-PCMTKP-g-PAN. The swelling behavior of the hydrogel was studied by carrying out its absorbency measurements in low conductivity water, 0.15 mol·L^-1 salt （NaCl, CaCl2 and AlCl3） solutions and simulated urine （SU） solution at different timings. FTIr, TGA and SEM techniques were used to characterize the products.

关键词： Sodium salt of partially carboxymethylated tamarind kernel powder Acrylonitrile Graft copolymerization Superabsorbent hydrogels Swelling behavior.

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宝岛

宝岛

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作者： r.L.·斯蒂文生(r.L. Stevenson)

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Electrochemically Assisted Photocatalytic Oxidation of Methanol on TiO_2 Nanotube Arrays

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Journal of Materials Science & Technology 2010年第6期26卷 535-541页

作者： r.Mohammadpour A.Iraji zad N.Taghavinia M.rahman M.M.Ahadian Institute for Nanoscience and Nanotechnology Sharif University of Technology Department of Physics Sharif University of Technology

The influence of an externally applied bias on photocatalytic performance of crystallized TiO2/Ti nanotubular electrode formed by anodization in fluoride-based electrolyte were investigated and compared to the behavior of multiporous TiO2 electrode. The photoelectrocatalytic oxidation behavior of methanol over the nanotubular electrode has been studied by measuring photocurrent response, potentiodynamic polarization spectroscopy and using electrochemical impedance spectroscopy （EIS）. It was found that the photoelectrocatalytic oxida- tion and the charge transfer rate constant of reaction on TiO2/Ti nanotubular electrode can significantly be increased by applying electrochemical bias. Moreover, TiO2 electrodes have considerably better performance alytic performance. based on the results, it was found that the nanotubular in comparison with porous samples in photoelectrocatalytic performance.

关键词： TiO2 nanotube Photoelectrocatalyst Electrochemical impedance spectroscopy Methanol

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Influence of Multi-pass Friction Stir Processing on Microstructure and Mechanical Properties of Die Cast Al–7Si–3Cu Aluminum Alloy

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Acta Metallurgica Sinica(English Letters) 2016年第5期29卷 431-440页

作者： L.John Baruch r.raju V.Balasubramanian A.G.rao I.Dinaharan Department of Mechanical Engineering Madanapalle Institute of Technology and ScienceMadanapalleAndhra Pradesh 517325India Department of Industrial Engineering College of EngineeringAnna UniversityChennaiTamil Nadu 600025India Department of Manufacturing Engineering Centre for Materials Joining and Research(CEMAJOR)Annamalai UniversityAnnamalai NagarChidambaramTamil Nadu608002India Marine Materials Division Naval Materials Research LaboratoryThaneMaharashtra 421506India Department of Mechanical Engineering Science University of JohannesburgAuckland Park Kingsway CampusJohannesburg 2006South Africa

The influence of overlap multi-pass friction stir processing on the microstructure and the mechanical properties, in particular, strength, ductility and hardness of die cast A1-7Si-3Cu aluminum alloy was investigated. It was observed that increase in the number of overlap passes friction stir processing resulted in significant refinement and redistribution of aluminum silicon eutectic phase and elimination of casting porosities. The microstructural refinement by the friction stir processing not only increases the ultimate tensile strength from 121 to 273 MPa, but also increases the ductility as observed by the increase in fracture strain from 1.8% to 10%. Analysis of the fractured surface reveals that the microstructural refinement obtained by friction stir processing plays a vital role in transforming the fracture mode from completely mixed mode to the ductile mode of the fracture with increasing number of passes. The change in the size, shape, morphology and distribution of eutectic silicon particles and elimination of the porosities are the main reasons for the increases in tensile strength and ductility due to friction stir processing.

关键词： Friction stir processing Overlap multi-pass Microstructure Mechanical properties

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Phase transformation and crystal growth behavior of 8mol%(SmO1.5, GdO1.5, and YO1.5) stabilized ZrO2 powders

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 842-849页

作者： r.Mahendran S.P.Kumaresh Babu S.Natarajan S.Manivannan A.Vallimanalan Department of Metallurgical and Materials Engineering National Institute of Technology Tirchirappalli 620015 Tamil Nadu india

Nanocrystalline powders of ZrO_2–8mol%SmO1.5（8Sm SZ）, ZrO_2–8mol%GdO1.5（8Gd SZ）, and ZrO_2–8mol%YO1.5（8YSZ） were prepared by a simple reverse-coprecipitation technique. Differential thermal analysis/thermogravimetry（DTA/TG）, Fourier transform infrared spectroscopy（FTIr）, X-ray diffraction（XrD）, raman spectroscopy, and high-resolution transmission electron microscopy（HrTEM） were used to study the phase transformation and crystal growth behavior. The DTA results showed that the ZrO_2 freeze-dried precipitates crystallized at 529, 465, and 467°C in the case of 8Sm SZ, 8Gd SZ, and 8YSZ, respectively. The XrD and raman results confirmed the presence of tetragonal ZrO_2 when the dried precipitates were calcined in the temperature range from 600 to 1000°C for 2 h. The crystallite size increased with increasing calcination temperature. The activation energies were calculated as 12.39, 12.45, and 16.59 k J/mol for 8Sm SZ, 8Gd SZ, and 8YSZ respectively.

关键词： zirconia thermal analysis reverse coprecipitation activation energy

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Synthesis and Characterization of Zinc Succinate, Zn(C4H4O4)

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Chemical research in Chinese Universities 2001年第1期17卷 20-25页

作者： ZHENG Yue qing ** (Institute for Solid State Chemistry, Ningbo University, Ningbo 315211, P. r. China) 宁波大学浙江宁波 315211 Max-Planck Institute fur Festkor per forschung 德国 D-70569

PETErS Karl and von SCHNErING Hans Georg (Max Planck Institute für Festkrperforschung, D 70569 Stuttgart, Germany)Zn(C 4H 4O 4) prepared by dissolving 0.483 g (1.41 mol) of Zn 3(OH) 4CO 3·H 2O and 0.5 g (4.23 mol) of C 4H 6O 4 in 50 mL of H 2O followed by slow evaporation at room temperature crystallizes in the monoclinic space group C 2 with the cell parameters a =0.757 9(1) nm, b =0.597 6(1) nm , c =0.626 5(1) nm, β =108.45(1)°, V =0.269 17(7) nm 3, D x=2.239 \{g/cm 3\}, Z =2 and the final r(F o)=0.039 and wr(F o 2)=0.088 for 396 reflections [ F o 2≥2 σ(F o 2)]. In the crystal structure unit, each Zn is tetrahedrally coordinated by four O atoms from four (C 4H 4O 4) 2- anions, each of which, in turn, bridges four Zn atoms to build up a 3D \{\} 3 ∞[Zn(C 4H 4O 4) 4/4 ] network. The thermal analyses indicate that Zn(C 4H 4O 4) is stable below 420 ℃.

关键词： Synthesis Zinc succinate Crystal structure Thermal decomposition

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Electron raman scattering in semiconductor quantum well wire of cylindrical ring geometry

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Chinese Physics B 2015年第11期24卷 442-447页

作者： re.Betancourt-riera ri.Betancourt-riera J.M.Nieto Jalil r.riera Instituto Tecnol ógico de Hermosillo.Avenida Tecnol ógico S/N Col.Sahuaro Departamento de Investigaci ón en Física Universidad de Sonora Tecnol ógico de Monterrey-Campus Sonora Norte.Bulevar Enrique Mazón López No.965

We study the electron states and the differential cross section for an electron raman scattering process in a semi- conductor quantum well wire of cylindrical ring geometry. The electron raman scattering developed here can be used to provide direct information about the electron band structures of these confinement systems. We assume that the system grows in a GaAs/Al0.35Ga0.65As matrix. The system is modeled by considering T = 0 K and also a single parabolic con- duction band, which is split into a sub-band system due to the confinement. The emission spectra are discussed for different scattering configurations, and the selection rules for the processes are also studied. Singularities in the spectra are found and interpreted.

关键词： electron states raman scattering selection rules quantum well wires

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Clinical relevance of the relationship between changes in gut microbiota and bile acid metabolism in patients with intrahepatic cholangiocarcinoma

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Hepatobiliary Surgery and Nutrition 2020年第2期9卷 211-214页

作者： Elisa Herraez Marta r.romero rocio I.r.Macias Maria J.Monte Jose J.G.Marin Experimental Hepatology and Drug Targeting(HEVEFArM) IBSALUniversity of SalamancaSalamancaSpain National Institute for the Study of Liver and Gastrointestinal Diseases(CIBErehd) Carlos III National Health InstituteMadridSpain

Although only 10-15%of liver cancers are cholangiocarcinomas(CCAs),which derive from the epithelial cells of the biliary tree,these cancers constitute a serious and growing health problem *** rate of mortality due to this tumor is very high because CCA usually appears in aged people and very often,in more than 70%of cases,are diagnosed late because of:(I)their anatomical localization in a big organ like the liver;(II)the lack of specific symptoms during most time of their development;and(III)the absence of available accurate,specific and sensitive biomarkers(1).These characteristics reduce the rate of success of surgical resection,which is the only curative option for CCA patients,because the response of this aggressive cancer to the available pharmacological armamentarium is extremely feeble(2).This justifies the interest of many groups to identify non-invasive markers to achieve early diagnosis that also permit to distinguish CCA from non-malignant biliary diseases and from hepatocellular carcinoma(HCC),the most frequent liver cancer,which derives from hepatocytes(3).

关键词： metabolism patients diagnosis

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