Effect of copper ions implantation on the corrosion behavior of ZIRLO alloy in 1 mol/L H2SO4

1. IntroductionZIRLO alloy is widely used in the nuclear industrybecause of its low thermal neutron capture cross sec-tion, favorable mechanical properties, and good corro-sion resistance. For example, ZIRLO alloy can serve asfuel cladding, spreaders for …     

Ni+离子注入AlN薄膜的磁性研究

用40 kV的Ni+离子在室温下对玻璃衬底上生长的AlN薄膜进行离子注入,注入剂量为5.0×1016 ions/cm2,在N2气氛下分别经400℃,600℃退火1h后,用超导量子干涉仪分析样品磁学特性.结果表明,Ni注入AlN薄膜未退火样品显示铁磁性;经400℃退火后铁磁性增强,居里温度大于室温;经600℃退火后样品铁...     

SURFACE ELECTRICAL PROPERTIES AND STRUCTURE OF YTTRIA-PARTIALLY-STABILIZED ZIRCONIA IMPLANTED WITH 57Fe IONS

Sintered plates of 5mol% yttria-partially-stabilized zirconia have been implanted at room temperature with 5×1015to 2×1017 Fe+ ions/cm2 at 140 KeV.Electrical measurement,Rutherford backscattering spectroscopy(RBS),Raman spectroscopy and X-ray photoelectron spectroscopy(XPS) have been used to study the surface electrical properties and the structure of the implanted layer before and after thermal annealing treatment in N2.     

Antibacterial Activity of Cu~(2+)-ZnO-modified 13X Zeolite against E.coli and S.aureus

A new type of zeolite composite antibacterial agents was prepared by introducing zinc oxide and copper ions into 13 X zeolite through the coprecipitation and ion-exchange methods. The structural properties of the tested antibacterial material were characterized and the antibacterial activity was evaluated. In Cu~(2+)/ZnO-13 X(CZ-13), zinc oxide and copper ions were either embedded in the interlayer space or dispersed on surface of 13 X zeolite. Excellent antimicrobial activity of CZ-13 was observed on Escherichia coli(E. coli) and Staphylococcus aureus(S.aureus). In the case of Cu~(2+)/ZnO-13 X, both MIC and MBC against E.coli were 0.2 mg/mL and 0.8 mg/mL. For S.aureus, CZ-13 also showed similar antibacterial properties. The bacterial cells turned from normal rod-shape into irregular shapes after treatment with the tested CZ-13. An increase of the intracellular enzyme activity after CZ-13 addition suggested that the permeability of the cell membrane increased and bacteria were damaged.     

Adsorption behavior and mechanism of copper ions in the sulfidization flotation of malachite

Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy (XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.     

Effect of Annealing Process on Microstructure and Mechanical Properties of Ultrafine Copper Prepared by Spark Plasma Sintering

The spark plasma sintering (SPS) method is used to prepare the ultrafine copper with the average grain size less than 10 μm and the tensile strength greater than 280 MPa.The ultrafine copper is annealed at different temperatures for 60 min,and the annealing microstructure is observed and the hardness and the deformation behavior of the bulk copper are tested.The results indicate that the grains grow very slowly when the annealing temperature is less than 450 ℃.However,the grain growth becomes remarkable whe...     

STUDY ON COMPLEX IMPEDANCE SPECTROSCOPY OF CU-IMPLANTED SEMICONDUCTING (BaO.72PbO.28)TiO3 CERAMICS

The ac impedance of Nb-doped semicon-ducting (Bao.72Pbo.28)TiO3 ceramics implanted with copper ions(200keV,6X1015 and 1X1017 ions/cm2) in the temperature range 25-320C and the frequency range 10 Hz -13MHz was measured. According to the change of impedance spectroscopy and the equivalent circuit model of semiconducting(Ba, Pb)TiO3 ceramics, the dependence of resistance of bulk and grain-boundary on temperature was analyzed. The results show that relatively low dose must be used to increase the magnitude of the positive temperature coeffieient of resistance(PTCR)effects in the cermmics. In addition,the effects of Cu ion implantation on the PTCR behavior of the ceramics was studied by raststance-tempera-ture measurement.     

Fe离子注入Al_2O_3陶瓷改变其表面电阻率的研究

本文研究了Fe离子注入Al_2O_3陶瓷的注入射程、纵向浓度分布和注入层结构,测定了注入层中的载流子浓度和迁移率,讨论了Al_2O_3陶瓷注入Fe离子其表面层的导电机理。其结论是:注入的Fe~(2-)离子进入Al_2O_3晶格,替代了Al~(3-)离子形成替位杂质。这样注入离子与原有晶格比较呈现一个有效负电荷,形成负电中心。它可以把一个空穴束缚在它的周围,在禁带引入受主能级。     

Influence of Aluminum Ions Implantation on Corrosion Behavior of Zircaloy-2 Alloy in 1M H2SO4

The specimens were implanted with aluminum ions with fluence ranging from 1× 10^16 to 1× 10^17 ions/cm^2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by metal vapor vacuum arc source （MEVVA） at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）, respectively. Transmission electron microscopy （TEM） was used to examine the microstructure of the aluminum-implanted samples. Glancing angle X-ray diffraction （GAXRD） was employed to examine the phase transformation due to the aluminum ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-2 in a 1 M H2SO4 solution. It is found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-2 implanted with aluminum ions. Finally, the mechanism of the corrosion behavior of aluminum- implanted zircaloy-2 was discussed.     

退火处理对Ti-Zr-Cu-Be块体非晶合金力学性能的影响

采用铜模铸造法制备了直径为2mm的Ti55-xZr10+xBe27.5Cu7.5(x=0,10,20)块体非晶合金,并对其进行等温退火处理.利用X射线衍射(XRD)、扫描电镜(SEM)、差氏扫描量热仪(DSC)及压缩试验等方法研究了非晶合金的相结构、显微组织和热稳定性,以及退火处理对其力学性能的影响.结果表明:该系列合金在553 K及583 K下保温长达5 h时间内依然表现为非晶态.退火处理后,Ti35Zr30Be27.5Cu7.5合金屈服强度、断裂强度均提到了提高,其中在583 K下保温1 h后屈服强度、断裂强度分别达到了1 921、2 169 MPa;其塑性由处理前的3.47%提高到了6.57%.Ti45Zr20Be27.5Cu7.5合金在退火后其力学性能变化不明显.Ti55Zr10Be27.5Cu7.5合金随着退火温度及保温时间的增加其屈服强度、断裂强度及塑性均明显降低.     

工艺因素对铜-铝-铜复合板界面结合的影响

为了减轻导电材料的结构质量,在铝板两侧放置铜带制备出一种铜-铝-铜复合结构,采用冷轧工艺进行轧制成形.系统研究了轧制压下率和轧前表面处理对轧制复合效果的影响,对铜-铝-铜复合板结合界面进行了观察,分析了退火对结合界面的影响.结果表明,随着压下率的增加,复合板的剥切力增加.改变铜带厚度时,复合板的剥切力随铜铝厚度比的减小而增大.当铝板厚度为12 mm、铜铝厚度比为0. 06时,轧制复合效果最佳.冷轧复合前处理影响因素中,刷拭处理对复合效果影响最大,铜铝软化退火处理次之,酸碱洗处理影响最小.复合板结合界面在轧制后发生了互扩散.在250℃下进行不同时长退火时,复合板中形成了明显的扩散层.当退火时间为50 h时,复合板中出现了两层扩散层,扩散层厚度随退火时间的增加而增加.     

磁性MnFe2O4/Ag复合纳米粒子的 制备与抑菌性能测试

采用水热法合成了磁性空心MnFe2O4纳米粒子,然后用3-氨丙基三乙氧基硅烷对其表面进行了改性并吸附银离子,还原后成功制备了磁性MnFe2O4/Ag复合纳米粒子,并采用X射线衍射仪、透射电镜、磁强计、紫外光谱等对试样进行了表征.通过抑菌圈法对MnFe2O4/Ag复合纳米粒子的抑菌性能进行了测试.结果表明:磁性空心MnFe2O4纳米粒子没有抑菌性能;MnFe2O4/Ag对大肠杆菌的抑菌圈半径为1.78 cm,对金黄色葡萄球菌的抑菌圈半径为2.14 cm;MnFe2O4/Ag的抑菌持久性检测结果说明,所制备的载银磁性复合纳米粒子抑菌剂的稳定性较好,抑菌性能较持久.     

钛离子注入对镀膜光白托力克玻璃光学性能的影响

将钛离子以不同的剂量、能量注入到镀膜光学白托片中进行表面改性。利用UV－240型紫外可见分光光度计、DP－A302型红外分光光度计、激光椭圆测厚仪等仪器,测定了注入前后及退入前后膜层析射率、紫外反向吸收等光学性质并加以分析,发现经离子注入及退火,玻璃的折射率得到提高,玻璃对红外、紫外的吸收增强。     

Implantation induced defects and electrical properties of Sb-implanted ZnO

Defects in Sb implanted Zn O single crystals have been studied by using photoluminescence(PL) spectroscopy,X-ray diffraction(XRD) and Raman scattering.Electrical properties of the samples were analyzed by Hall effect measurement.The results indicate that the annealed Sb-implanted sample is n-type with a free electron concentration of the same amplitude as the calculated implantation concentration.The well-known oxygen vacancy related deep level green PL band is suppressed in the as-implanted sample and recovers to the level close to the as-grown Zn O single crystal after annealing.These phenomena suggest that a large portion of as-implanted Sb atoms occupy oxygen lattice site in an unstable state and move to the interstitial site,forming the complex donor defect upon high temperature annealing,resulting in n-type conduction even if the implantation dose is quite high.     

Nanophase formation and its behavior of corrosion resistance in C+Ti dual implanted steel

After corrosion and pitting corrosion, the wire nanometer phases are observed using a transmission electron microscope (TEM) in C + Ti dual implanted H13 steel. The property of corrosion resistance dual-implanted (C + Ti) H13 steel is studied using multi-sweep cyclic voltammetry. TEM images of the cross section of an implanted sample reveal plenty of circular nanometer structures with diameters of 10-30 nm. The phases are densely embedded in the implanted layer. The embedded structure improves the surface corrosion resistance, as can be observed with a scanning electron microscope (SEM). The phases with the shape of a tiny wire in nanometer size are formed. The nanometer phases, consisting of TiC, FeTi and FeTi2, are formed in dual implanted layer. The corrosion current peak density decreases to 1/16-1/10 that of the unimplanted H13 steel. The formation conditions of the nanometer phases and their effects are investigated. The passivation layer consists of nanometer phases. The corrosion resistance of th     

Property improvement of multilayer TiN/Ti films with C+ implantation

Using the MEVVA ion source, carbon ions have been implanted in TiN coatings deposited by multiarc ion plating. The Vickers microhardness of the C⁺-implanted TiN films increased with the increase in the ion flux and dose. X-ray diffraction (XRD) analysis showed that the TiC phases had been formed in the films. In addition, the films had the preferred growth orientations of TiN and TiC, both of which were (111) orientation after annealing at 500°C for 30 min. Auger electron spectra analysis indicated that C⁺-implanted profile was in typical Gaussian-like distribution in single films. The distribution with multipeaks of C atoms was obtained in multi-layer TiN/Ti. The possibility of the multilayer films (Ti(C,N)/TiN/Ti(C,N)/TiN and Ti(C,N)/TiC/Ti(C,N)/TiC) forming using the C-implanted TiN/Ti films is presented for the first time. Project supported by the National Natural Science Foundation of China and the “863” Hi-Tech Program of China.     

Effects of annealing on microstructure, mechanical and electrical properties of AlCrCuFeMnTi high entropy alloy

The multi-component A1CrCuFeMnTi high entropy alloy was prepared using a vacuum arc melting process. Serial annealing processes were subsequently performed at 590 ℃, 750 ℃, 955 ℃ and 1 100 ℃ respectively with a holding time of 4 h at each temperature. The effects of annealing on microstructure, mechanical and electrical properties of as-cast alloy were investigated by using differential thermal analysis （DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The experimental results show that two C14 hexagonal structures remain unchanged after annealing the as-cast A1CrCuFeMnTi alloy specimens being heated to 1 100℃. Both annealed and as-cast microstructures show typical cast-dendrite morphology and similar elemental segregation. The hardness of alloys declines as the annealing temperature increases while the strength of as-cast alloy improves obviously by the annealing treatment. The electrical conductivities of annealed and as-cast alloys are influenced by the distribution of interdendrite re~ions which is rich in Cu element.     

Chemical Property and Antibacterial Activity of Metronidazole-decorated Ti through Adhesive Dopamine

In order to present a novel metronidazole-decorated Ti implanted with antibacterial activity through adhesive dopamine, and prepare metronidazole-decorated Ti, Ti substrates were pre-modified with dopamine(DA) coating, and metronidazole was subsequently immobilized onto the surface of DA-modified Ti substrates. The prepared MET-decorated Ti interfaces were prepared for surface characterization tests:contacting angle measurements, scanning electron microscope, ATR-FTIR spectroscopy and in vitro anti-biofilm formation assay. Statistical tests were performed using by SPSS16.0. Contacting angle measurement, scanning electron microscopy, and ATR-FTIR spectroscopy confirmed the successful presence of MET grafted on the Ti surface. In addition, the MET-decorated Ti induced good in vitro antibacterial activity toward Escherichia coli and Streptococcus mutans,Gram-negative and Gram-positive bacteria, respectively. The modified Ti substrate with enhanced antibacterial activity holds a great potential as implanting material for applications in dental and bone graft substitutes.     

H2SO4溶液中表面改性铝电极的电化学性能研究

在弱极化区测量了H2SO4溶液中表面改性铝电极的阳极极化曲线。研究了表面覆盖层对极板在H2SO4介质中电化学腐蚀性能的影响。由弱极化区数据,利用Vicor程序分别计算了三个铝电极的腐蚀电流密度、阴、阳极Tafel参数。同时研究了H2SO4溶液中氢在铝电极上的过电势。结果表明,在H2SO4溶液中,离子注入铅的铝电极的耐蚀性最佳,且具有较高的析氢过电势。     

Preparation of immobilized <Emphasis Type="Italic">ɛ</Emphasis>-polylysine PET nonwoven fabrics and antibacterial activity evaluation

A novel antibacterial material (L-PET) was prepared by immobilizing ε-polylysine on polyethylene terephthalate (PET) nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy (SEM) was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy (XPS) were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.