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1

Corrosion Resistance Of Electroless Ni-P/Cu/Ni-P Multilayer Coatings

100%

Zhao G. L. , Zou Y. , Hao Y. L. , Zou Z. D.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 2A

1003--1008

EN

Ni-P/Cu/Ni-P multilayer coatings were prepared by deposition of Cu layer between two Ni–P layers. The Cu layer was deposited by metal displacement reaction between Cu2+ and Fe atoms. Corrosion behavior of single-layer Ni-P coatings, double-layer Ni-P/Cu coatings, and three-layer Ni-P/Cu/Ni-P coatings were investigated by electrochemical tests in 3.5% NaCl solution. The three-layer coatings exhibited more positive Ecorr and decreased Icorr compared with conventional single-layer Ni-P coatings, which indicated an improved corrosion resistance. The polarization curves of the three-layer coatings were characterized by two passive regions. The improved corrosion resistance was not only attributed to the function of the blocked pores of Cu. The Cu interlayer also acted as a sacrificial layer instead of a barrier in the coatings, which altered the corrosion mechanism and further improved the corrosion resistance of the coatings.

PL

Wielowarstwowe powłoki Ni-P/Cu/Ni-P wytworzono metodą osadzania miedzi pomiędzy dwoma warstwami Ni-P. Warstwę Cu otrzymano dzięki reakcji wypierania metalu przez metal (dla miedzi i żelaza). Aby określić właściwości korozyjne jednowarstwowej powłoki Ni-P, dwuwarstwowej Ni-P/Cu oraz trójwarstwowej Ni-P/Cu/Ni-P przeprowadzono pomiary elektrochemiczne w 3,5% roztworze NaCl. Powłoki trójwarstwowe w porównaniu do jednowarstwowych wykazały się większą wartością Ecorr, przy malejącej wartości Icorr. Wskazuje to na poprawę odporności na korozję. Krzywe polaryzacji dla powłok trójwarstwowych charakteryzują się występowaniem dwóch obszarów pasywacji. Poprawa odporności na korozję jest skutkiem nie tylko tzw. zjawiska blokowania porów w miedzi. Powłoka z Cu działała także jako warstwa protektorowa, modyfikując mechanizm korozji i poprawiając odporność korozyjną powłok.

2

The growth morphology of ZnO hexangular tubes synthesized by the solvothermal method

100%

Li Y. , Liu X. , Zou Y. , Guo Y.

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tom Vol. 27, No. 1

187--192

EN

A novel hexangular tube structure of ZnO has been successfully synthesized via the solvo-thermal method, using Zn(NO3)2o6H2O and NaOH as starting materials. The results showed that the supersaturation near the surface of ZnO crystal is higher than that inside the crystal, which leads to a preferential growth along c-axis of the side surface. The strain between the surface and the bulk of ZnO rods drives ZnO rods into tubular structure. The spectroscopic results show that ZnO tubes possess the wurtzite structure. Three emission peaks have been detected, a violet peak at about 399.9 nm, a blue emission at about 448.5 nm and a green emission at about 549.8 nm.

3

Effects Of Anodic Protection On SCC Behavior Of X80 Pipeline Steel In High-pH Carbonate-Bicarbonate Solution

100%

Zhao W. , Zou Y. , Xia D. X. , Zou Z. D.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 2A

1009--1013

EN

The potentiodynamic polarization test and slow strain rate tensile tests of X80 pipeline steel were performed in 0.5M Na2CO3-1M NaHCO3 solution to study the electrochemical and stress corrosion cracking properties. The results of potentiodynamic polarization test show that there is an obvious stable passive region, about from 0v to 0.8V (SCE), indicating that anodic protection is feasible. The results of slow strain rate tensile tests show that the stress corrosion cracking sensibility is high and cathodic protection effect is restricted due to the hydrogen permeation. However, the elongation, yielding strength and tensile strength all increase with anodic protection. The higher anodic protection potential in the stable passive region is benefit to improve tensile strength and yielding strength. However, the higher elongation is obtained at 0.5V (SCE) anodic protection potential.

PL

Badania polaryzacji potencjodyniamicznej oraz próby powolnego rozciągania (SSRT) przeprowadzono na stali typu X80 w roztworze 0,5M Na2CO3-1M NaHCO3. Określono odporność na korozję elektrochemiczną oraz zbadano zjawisko naprężeniowego pękania korozyjnego. Rezultaty badań polaryzacji potencjodynamicznej wykazały istnienie stabilnego obszaru pasywacji w zakresie potencjału od 0V do 0,8V (SCE: półogniwo odniesienia – elektroda kalomelowa). Próby powolnego rozciągania pokazały wysoką wrażliwość materiału na naprężeniowe pękanie korozyjne i ograniczenia ochrony katodowej w związku z przenikaniem wodoru. Ochrona anodowa natomiast, zwiększa znacząco wydłużenie próbki, granicę plastyczności oraz wytrzymałość na rozciąganie. Ponadto zwiększanie wartości potencjału w stabilnym obszarze pasywacji dodatkowo poprawia te właściwości.

4

Thermal stability and mechanical properties of sputtered Chromium-Molybdenum-Nitride (CrMoN) coatings

88%

Zou Y. , Walock M. J. , Catledge S. A. , Nouveau C. , Stanishevsky A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 37, nr 2

369-374

EN

Purpose: The purpose of paper is to determinate thermal stability and mechanical properties of sputtered chromium-molybdenum-nitride (CrMoN) coatings. Design/methodology/approach: We have deposited 1.8 m-thick ternary Cr0.5Mo0.5N1.0 films on a CoCrMo alloy using a RF dual magnetron sputtering system, with Cr and Mo targets and N2 as the reactive gas. These films were subjected to various thermal treatments in Ar, air, and microwave plasma. The hardness, Young’s modulus, surface roughness, microstructure, and composition of films were studied by nanoindentation, AFM, x-ray diffraction, and x-ray photoelectron spectroscopy. Findings: The as-prepared CrMoN films consist of an amorphous Cr-rich nitride matrix with Mo-rich nitride crystalline grains, about 15 nm in size. These films are thermally stable up to 600şC in air. Thermal annealing in the air at 800şC resulted in an increase in surface roughness and hardness, due to film oxidation, with Cr2O3 as the main crystalline phase. Plasma treatment in a H2/N2 gas mixture, at 800şC, did not lead to grain growth. Instead, the existing grains were reduced to about 10 nm and a new nanocrystalline phase has been formed. This leads to a decrease in the surface roughness, and an increase in the film hardness. In addition, we have further modified the film properties through a combined thermal treatment process. Thermal annealing in the air at 800şC, followed by microwave plasma treatment at 800şC resulted in a film with decreased surface roughness, and improved mechanical properties. Reversing the order of the thermal treatments resulted in a further decrease in surface roughness, but it shows a reduction in the mechanical properties. Research limitations/implications: The present investigation was carried out with only one composition, Cr0.5Mo0.5N1.0, of ternary thin-film system. Originality/value: The combination of thermal and plasma treatments can be used to control the microstructure, surface topography, and mechanical properties of ternary CrMoN films. Such post-deposition treatments can further improve the materials properties for desired application, and to produce new nanocomposite materials with technologically important combination of properties.

5

Synthesis of porous ZnO nanostructures using bamboo fibers as templates

75%

Lian X. , Li Y. , An D. , Zou Y. , Wang Q. , Zhang N.

Materials Science Poland

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2014

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tom Vol. 32, No. 3

514--520

EN

In this study, we fabricated ZnO nanostructures using bamboo fibers as templates. The starting material used was zinc acetate, and the nanostructures were synthesized by soaking and calcining the bamboo fibers. The fabricated nanostructures were characterized using X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), and ultraviolet-visible spectrophotometry. The results showed that the size of the ZnO nanoparticles was approximately 20–100 nm. When the ZnO nanoparticles were used as the catalyst in the photodegradation of methyl orange, the dye degraded by 95.98 % in 80 min. The response and recovery times of a gas sensor based on the ZnO nanoparticles were 25 and 24 s, respectively, during the detection of C2H5OH in a concentration of 10 ppm at 270 °C.

6

Effects of soil moisture content on the growth and physiological status of ginger (Zingiber officinale Roscoe)

75%

Li H. , Huang M. , Tan D. , Liao Q. , Zou Y. , Jiang Y.

Acta Physiologiae Plantarum

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2018

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tom 40

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nr 07

7

Occurrence of Anaplasma phagocytophilum in goats and sheep in Hebei Province, China

75%

Liu J. , Li Y. , Pan S. , Zou Y. , Chen L. , Liu X. , Wang Q.

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nr 12

EN

Anaplasma phagocytophilum is an emerging pathogen known to cause human granulocytic anaplasmosis (HGA). Here we determined the prevalence and genetic characterization of A. phagocytophilum in Hebei Province, China. A total of 253 samples were taken from goats and sheep in Hebei Province, and 52 (20.6%) were positive for A. phagocytophilum. There was a higher positive rate in sheep (23.8%, 20/84) than in goats (18.9%, 32/169). Analysis of the partial 16S RNA gene sequences of A. phagocytophilum revealed that the isolates in this study were members of the same clade and were 100% homologous with each other. This study provides information on the epidemiologic features of A. phagocytophilum.

8

SRPX2 promotes cell proliferation and invasion via activating FAK/SRC/ERK pathway in non-small cell lung cancer

63%