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1.
本文研究了用溶胶-凝胶(Sol-gel)法制备Al2O3系陶瓷涂层的工艺过程和反应原理,阐述了溶胶制备,涂层工艺及其影响因素等问题,结果表明,涂层的性质与溶胶的性质、溶胶与基层的润湿性认及徐覆工艺有关。Al(OH)3溶胶的粘度应控制在24~46cp,烧结加热速率不易高于1℃/min;选用添加剂和多次涂覆技术等可以增加涂层厚度。  相似文献   

2.
北祁连奥陶系阴沟群硅质岩对该地区的沉积环境和构造背景具有重要的指示意义,目前多认为其形成于大陆边缘环境。北祁连西水地区奥陶系阴沟群中的硅质岩 w(SiO2)值、Si/Al值、Al/(Al+Fe+ Mn)值、Fe/Ti值、(Fe+ Mn)/Ti值、
w(∑REE)值等地球化学特征均指示硅质岩为热水沉积成因;Al2O3/(Al2O3+Fe2O3)值、U/Th值、Ti/V 值、(La/Ce)N 值、δCe值指示其形成于大陆边缘环境;w(Al2O3)值与w(MgO)值、U/Th值、Al2O3/TiO2 值均反映硅质岩在形成过程中受到了陆源碎屑的影响;Al2O3、TiO2、Cr、Rb、Ba、Zr质量分数特征及稀土元素配分模式表明硅质岩的形成与岛弧以及弧后盆地有关。综 合 分析与奥陶系硅质岩伴生的火山岩岩石组合特征以及区域构造演化背景,认为西水地区奥陶系阴沟群硅质岩应属大陆边缘背景下,其弧后盆地靠近岛弧一侧的产物。这为进一步细化研究北祁连奥陶纪沟-弧-盆体系的空间格局提供了重要的沉积学依据。   相似文献   

3.
本矿床是我国金红石矿床重要的成因及工业类型,为具有特定化学成分的岩石在特定变质条件下形成的。本文通过对大量数据的处理,查明了化学成分与成矿的关系:高Al2O3、MgO、Fe2O3+FeO、K2O、P2O5、H2O+、MnO,低SiO2、CaO、Na2O、CO2、S等,利于钛富集;高TiO2、MgO、P2O5、S,低SiO2、CaO、K2O、Al2O3、Fe2O3/FeO,利于金红石形成;高Sc、Zr、Ni、Zn及La/Yb,低Y、Nb、Th、Cd、Ba、Be、ΣREE,利于金红石纯度提高。对研究矿床成因及寻找新的同类矿床等有重要意义  相似文献   

4.
通过采集江汉平原沙湖原种场典型高砷地下水区的27个地下水样品、6个地表水样品和不同深度的沉积物样品,采用 X射线荧光光谱、离子色谱、TOC分析仪以及沉积物平行提取方法对该区含水层的水化学特征以及沉积物的地球化学特征进行了分析。结果表明:该区地下水水化学类型主要为 HCO3-Ca·Mg型,属中性偏弱碱性水;氧化还原电位较负,NH+4 -N、HS- 和 Fe(Ⅱ)质量浓度较高,指示地下水的强还原环境;地 下 水 As质 量 浓 度平均值为74.39μg/L,最大值达580.77μg/L,出现在地面以下25m 位置,且 As(Ⅲ)质量浓度普遍高于 As(V)。随深度增加,沉积物中 w(As)呈先增加后减小的趋势,在17.4m(黏 土层)深度处达到最大(21.15mg/kg),且w(As)随深度的变化与沉积物中 TOC、Fe2O3、Al2O3 质量分数以及沉积物比表面积随深度的变化呈现相同的趋势,采用SPSS软件经相关分析亦表明 As与 TOC、Fe2O3、Al2O3 和比表面积具有较强的相关关系,相关系数分别为0.70,0.68,0.70,0.67,揭示砷在富含有机质、铁铝氧化物及比表面积大的黏土层沉积物中更易富集。沉积物平行提取实验结果表明,江汉平原沉积物中的砷主要以强结晶态铁氧化物、溶解态硫化物和反应性硅酸盐的形式存在。   相似文献   

5.
本文研究了D_001大孔阳离子强酸树脂从H_2SO_4-CS(NH_2)_2溶液中,富集及分离Au(I)、Ag(I)的性能。表明在pH=2.0左右,树脂对Au(Tu) ̄+_2、Ag(Tu) ̄+_2(Tu=硫脲)有良好的吸附性能,Au和Ag的吸附容量分别为61.18mg/g-Resin和99.11mg/g—Resin。负载柱上的Au、Ag可分别用NaCN—NaOH和H_3BO_3-NaOH-Na_2S_2O_3定量洗脱。可进行一定程度的Au、Ag分离。  相似文献   

6.
本文确定了黄土中古土壤有四种双层淀积类型。第一和第二种是由两层CaCO3结核构成的,第三种是由CaCO3和CaSO4构成的,第四种是由CaCO3与Al2O3、Fe2O3构成的。根据CaCO3淀积层成因分析得知,西安附近第一层古土壤具二元发生特点。该层古土壤上部的CaCO3淀积层代表碱性土壤发育时期。下部的CaCO3淀积层代表中酸性土壤发育时期。因为有些古土壤发育时出现过气候变化,所以具CaCO3淀积层的古土壤不一定是碱性的。具CaCO3与Fe2O3·Al2O3构成的双层淀积是酸性土壤的标志。  相似文献   

7.
以TiO为材料制作的Al/TiO2/SiMIS结构对与鱼鲜度有关的三甲胺气体有良好的响应。实验表明:当三甲胺体积分数从0-10^3×10^-6变化时,在1MHZ的测试频率下,样品的电容值改变了250%;在3V的偏上,电流变化了450%。鲜鱼死后在25h内,在较高温度下样吕的(C-t)和(I-t)关系响应敏感,并通过分析了TiO2膜各组分的介电常数,解释了样品的电容随体积分数变化的机理。提出了吸附模  相似文献   

8.
四川石棉大水沟独立碲矿床堪称世界首例,其矿体两侧的围岩蚀变较窄,且蚀变带与矿脉及未蚀变岩呈清楚而截然的接触关系。主要围岩蚀变为白云石化、白(绢)云母化、云英岩化及电气石化等。这些蚀变作用分别发生于177.7~165.1Ma和91.71~80.19Ma。蚀变作用过程中SiO2大量析出,Al2O3、TiO2、CaO、MgO、K2O、H2O、CO2、Fe2O3、MnO则有不同程度地带入。与此同时,REE在此过程中包集体迁出,Te、Bi、AS等元素的含量则决定于蚀变作用及其强度,而与原岩无关。  相似文献   

9.
用氩离子束镀膜法制备BaTiO3/Si结构,并在400~900℃的温度下用氮气保护进行退火,用常规蒸铝技术制成Al/BaTiO3/Si湿度传感器。用俄歇电子能谱分析BaTiO3膜的化学组分。采用高频电容—电压测试仪测定BaTiO3/Si结构的固定电荷密度,分析固定电荷密度与退火的关系。结果表明:固定电荷密度达1011cm-2数量级。经900℃、60分钟退火后固定电荷密度下降至19%到20%。随着固定电荷密度的减少,湿度传感器的响应时间延长了60%,而击穿电压提高了7倍。  相似文献   

10.
功能梯度材料复合板的热应力计算分析   总被引:5,自引:0,他引:5  
对金属-功能梯度材料-陶瓷复合板结构进行了热应力分析,导出了功能梯度材料连续模型的温度分布及热应力分布的计算表达式,并就ZrO2/NiCrAl梯度材料热应力分布的解析解和有限元解进行了比较。计算结果表明:功能梯度材料连续板模型,便于结构的热应力分析和结构的优化设计,有利于梯度材料结构的非均等分层,可进一步减缓层间的应力突变和残余应力。  相似文献   

11.
The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.  相似文献   

12.
Cao  Pan  Liu  De  Liu  Yuhan  Wang  Huming  Zhang  Chao  Yuan  Chengqing  Liu  Xiaodan 《中国海洋湖沼学报》2023,41(1):174-188

Marine biofouling causes serious harms to surfaces of marine devices in transportation, aquaculture, and offshore construction. Traditional antifouling methods pollute the environment. A novel and green antifouling strategy was developed to prevent effectively the adhesion of bacteria and microalgae. An antifouling surface was fabricated via coating Turgencin BMox2 (TB) onto dopamine-modified 304 stainless steel (304 SS). The surface physical and chemical properties before and after modification were characterized by Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectrometer (XPS), contact angle measurement (CA), 3D optical profilometer, ellipsometer, and atomic force microscope (AFM). Antimicrobial peptide was coated onto the surface of 304 SS successfully, and the surface morphology and wettability of the modified sample were modified. Moreover, cytocompatibility of the peptide was evaluated by co-culture of peptide and cells, indicating promising cell biocompatibility at the modified sample surface. At last, antifouling performance and electrochemical corrosion were tested. Results show that the adhesion rates of Vibrio natriegens and Phaeodactylum tricornutum on the antifouling surface were reduced by 99.85% and 67.93%, respectively from those of untreated samples. Therefore, the modified samples retained superior corrosion resistance. The study provide a simply and green way against biofouling on ship hulls and marine equipment.

  相似文献   

13.
Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications.A composite coating system,including a primer,middle coat and topcoat,were used to protect carbon steel from corrosion in a marine environment.Two environmental additives,glass fi bers and thiourea,were applied in the middle coat to modify the coating system.The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods.Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.%fi bers and 0.5 wt.%thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5%Na Cl for 120 d.Evolution of localized corrosion factors with time,as obtained from the current distribution showed that fi bers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development signifi cantly.Surface characterization suggested that adequate thiourea could be absorbed uniformly on fi bers for a long time to play an important role in protecting the carbon steel.Finally,schematic models were established to demonstrate the action of fi bers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.  相似文献   

14.
INTR0DUCnONAlloycoatingscandetivelyproteCtsteelagainstcormsioninseri0uscormsionenvir-orunent,suchasthedrinesplashandtidalzones-TwoInainhodiptincaldrinumalloycOaingswidelyusedcommroiallyareGalfancoaing(contalningZn-5wt%kl-us)devel-oPedbytheIntemaionaltalZincReenhheZaionandhocoating(c0n-talningZn-55Wt%Al-1.6Wt%Si)develoPedbytheBethlehemSteelCorpOration-Anewrinc-basedalloycOaingdevel0PedbyNortheaStemUniversityisdiscussedinthesPaperbyelecthehendcalmethod.FromSun(l996),welmOWthecorms…  相似文献   

15.
研制适用于三元复合驱采油污水工况条件下的MPM固体缓蚀阻垢剂,分析三元复合驱采油污水中MPM的电化学特性.结果表明:随着温度增加,20#钢在采油污水的腐蚀速率呈增加趋势,极化曲线显示钝化区表面材料在表面高温下处于钝化状态,产生的钝化膜能够降低腐蚀速度.在阻垢缓蚀剂质量浓度相同的情况下,不同温度的电化学阻抗谱在高频区出现容抗弧,显示优良的缓蚀性能.不同质量浓度MPM极化曲线表明,缓蚀率随MPM质量浓度的增加而增大,MPM极值质量浓度为80mg/L.污水体系中的Ca2+、Cl-对缓蚀率产生影响.MPM适用于高质量浓度Ca2+的三元复合驱采油污水处理.  相似文献   

16.
Cai  Haoyuan  Wang  Peng  Zhang  Dun 《中国海洋湖沼学报》2020,38(4):1045-1063
Smart coating for corrosion protection of metal materials(steel,magnesium,aluminum and their alloys) has drawn great attention because of their capacity to prevent crack propagation in the protective coating by releasing functional molecules(healing agents or corrosion inhibitors) on demand from delivery vehicle,that is,micro/nanocontainer made up of a shell and core material or a coating layer,in a controllable manner.Herein,we summarize the recent achievements during the last 10 years in the field of the micro/nanocontainer with different types of stimuli-responsive properties,i.e.,pH,electrochemical potential,redox,aggressive corrosive ions,heat,light,magnetic field,and mechanical impact,for smart anticorrosion coating.The state-of-the-art design and fabrication of micro/nanocontainer are emphasized with detailed examples.  相似文献   

17.
The corrosion resistance of electroless Ni-P deposits with phosphorous contents from 12% to 14% in sodium chloride solutions was studied. The deposits were immersed in 3.5% NaCl solutions for 29 d to obtain the electrochemical parameters and were examined in a standard salt spray test for 15 d respectively. The corrosion resistance of the deposits was studied by poten- tio-dynamic scan, electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and cold-field emission scanning electron microscopy (FE-SEM) equipped with an energy dispersive X-ray detector (EDX). The patterns of XRD and the results of FE-SEM showed that the prepared deposits were amorphous. But after a 15 d standard salt spray test, a few pinholes appeared on the surface of the deposit and the weight content of phosphorus on the surface of the deposit was higher (which was beneficial to the formation of the passivation films) than that before the standard salt spray test when the nickel content was lower because the dissolved weight of nickel was greater than that of phosphorus. The results from potentio-dynamic scan and EIS showed that passivation films formed on the Ni-P deposit after immersion in the NaCl solutions, which decreased the corrosion rate of Ni-P samples. The results of this work show their potential applications in marine corrosion.  相似文献   

18.
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????????????????????????????·?????ù???????Bragg??????????????????淽??????????????????????????????????????α?????е??·?????????????п????????????????????????????????????????????  相似文献   

19.
As a material with good corrosion resistance,5083 aluminum alloy has a great application prospect in marine environment.In this work,the corrosion characteristics of 5083 aluminum alloy in seawater containing phosphate were investigated with Potentiodynamic Polarization,Electrochemical Impedance Spectroscopy (EIS),Scanning Electron Microscope (SEM),Energy Dispersive Spectroscopy Analysis (EDSA),X-ray Photoelectron Spectroscopy (XPS) and Laser Confocal Microscope.The results indicated that the effects of phosphate in seawater were two-fold.Firstly,phosphate slightly accelerated the corrosion of 5083 in seawater in the early stage of corrosion.HPO_4~(2-)competed with OH~-in the adsorption process on the alloy surface,which weakened the contact between OH~-and Al~(3+)near the interface of the alloy,and inhibited the formation as well as the self-repair of the passive film,thus accelerating the activation dissolution process.Compared with the natural seawater,the charge transfer resistance of 5083 in the seawater containing phosphate decreased faster during the early stage of corrosion,and the corrosion current density icorr was higher in seawater containing phosphate.On the other hand,the addition of phosphate would not affect the cluster distribution of the second phase of 5083 in seawater,but it changed the composition of the corrosion product layer and had an obvious inhibitory effect on the local corrosion of 5083 in seawater.After 16-day exposure,shallower and more sparsely distributed pits could be observed on the derusted surface of 5083 in the seawater containing phosphate,and the pitting coefficient in the seawater containing phosphate was significantly lower than that in natural seawater.The reduction of pitting tendency could be realized mainly through two ways.First,the HPO_4~(2-)adsorbed on the surface of the passive film in the early stage of corrosion and repeled the corrosive anions such as Cl~-.Second,phosphate participated in the construction of the Ca HPO_4 precipitation film,which acted as a barrier and protection.  相似文献   

20.
Zhang  Jie  Wang  Jia  Zhang  Binbin  Zeng  Yuxiang  Duan  Jizhou  Hou  Baorong 《中国海洋湖沼学报》2020,38(4):1246-1255
Marine corrosion and biofouling seriously affect the service life of marine structural materials,resulting in performance failure,enormous economic loss,and even catastrophic safety accidents.It is worthwhile and desirable to develop high-efficiency strategy for anti-corrosion and anti-biofouling.In this paper,superhydrophobic 5083 aluminum alloy(AA5083) surface with micro-nano hierarchical morphology was fabricated through anodization followed by 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane(POTS)modification.The surface morphologies,roughness,and chemical compositions were revealed by scanning electron microscopy,atomic force microscopy,and X-ray diffraction.The self-cleaning ability,corrosion resistance and algae adhesion suppression ability of the fabricated surfaces were investigated,indicating an excellent water-proofing,anti-corrosion and anti-biofouling performance.We believe the superhydrophobic creation of metallic materials is expected to have potential applications in marine corrosion and antibiofouling fields.  相似文献   

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