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1.
为改善镁合金有机电泳涂层耐磨性能,通过硅烷偶联剂改性陶瓷粉体,并将陶瓷粉体充分分散于电泳漆中制得镁合金阴极电泳复合涂层,用铅笔硬度、摩擦磨损测试系统、画圈附着力方法、氯离子腐蚀试验、分别评价比较了阴极电泳涂层和加粉体后复合涂层的硬度、附着力、耐蚀性和耐磨性能。结果表明:硅烷改性Al2O3粉体的阴极电泳有机无机复合涂层厚度与不加粉体的相当,粉体的加入不会改变涂层与基体的附着力和耐蚀性,但可以增加涂层的硬度,极大地提高涂层的耐磨性。  相似文献   

2.
钢铁表面免水洗锌系磷化膜的常温制备与性能表征   总被引:4,自引:0,他引:4  
Q235钢铁试片在以磷酸、氧化锌、钼酸铵等材料组成的锌系磷化液中常温快速磷化后,自然干燥2 h以上,生成免水洗的彩色锌系磷化膜.用XPS对膜层的化学组成及结构进行表征,用SEM和EDS对膜层的形貌和元素含量进行分析,探讨磷化机理.研究结果表明:免水洗的磷化膜,由Fe3 和Zn2 的磷酸盐及少量的钼酸盐等组成,膜晶粒尺寸≤2 μm,膜连续、致密,膜重≥0.9 g/m2,耐3%的NaCl溶液腐蚀约2.0 h,喷涂铁红环氧底漆后检验涂层的附着力达1级,比传统工艺(磷化后水洗)形成的磷化膜质量更好.  相似文献   

3.
昌河1986年开始批量生产汽车,磷化表面处理从一元锌系磷化到三元锌、镍、锰系的转变。由于新磷化药剂的使用,使磷化膜P比提高到0.9以上,提高了磷化膜的耐碱性。使电泳臻膜的耐盐雾性增强,减少了漆膜裂纹处发生的腐蚀。本文就昌铃涂装生产线现有的生产条件下阐述如何提高磷化膜的质量。分别从涂装工艺及前处理设备等方面对影响磷化膜的因素进行分析和讨论,并提出提高磷化膜质量的方法。在汽车涂装生产中,为了延长漆膜的耐盐雾性,普遍采用磷化处理作为油漆前的表面处理,磷化膜质量的好坏直接影响着涂装质量。  相似文献   

4.
用电化学方法加速低温磷化过程   总被引:3,自引:0,他引:3  
采用阳极、阴极和脉冲电流对磷化过程进行加速试验.并通过X射线衍射及膜耐蚀性、附着力等的测定.证明了用电化学方法可以在磷化液中不加促进剂,缩短磷化时间,降低磷化温度和膜重.改善膜的结构,提高膜的质量.结果还发现不同的电化学方法对磷化液有选择性.  相似文献   

5.
漆前常温条件下的锌系磷化液制备   总被引:1,自引:0,他引:1  
开发了一种在5~40 ℃条件下使用的钢铁表面漆前处理锌系磷化液.该磷化液由氧化锌、磷酸、六水硝酸锌、成膜助剂、促进剂浓度构成.所获得的磷化膜连续、均匀致密,膜重约1.5~2.9 g·m-2、耐蚀性和附着力好.  相似文献   

6.
镁合金微弧氧化-涂装体系的研究   总被引:7,自引:0,他引:7  
提出了一种镁合金/微弧氧化膜/有机涂层的镁合金防护体系.在以硅酸钠为主的复合溶液中,利用双向对称脉冲电压在阴、阳极镁合金表面同时微弧电沉积陶瓷膜.利用盐雾实验比较了以镁合金微弧氧化膜为基底并涂覆环氧底漆和聚胺脂丙烯酸面漆的试样与镁合金/微弧氧化膜/有机硅、镁合金/微弧氧化膜/溶胶凝胶涂装试样的耐蚀性,并利用盐雾实验与交流阻抗谱相结合跟踪对比分析了镁合金/有机涂层、镁合金/铬酸盐转化膜/有机涂层、镁合金/微弧氧化膜/有机涂层的屏蔽性能.结果表明:采用溶胶凝胶、有机硅和有机涂层对微弧氧化膜进行涂装的方法均可进一步提高镁合金的耐蚀性,其中镁合金/微弧氧化膜/有机涂层试样可承受480h以上的中性盐雾实验,且其介质屏蔽性能优于镁合金/有机涂层和传统的镁合金/铬酸盐转化膜/有机涂层防护体系.  相似文献   

7.
采用盐雾试验和电化学阻抗谱测试技术研究了纯锌和锌铝伪合金涂层在含氯离子环境中的腐蚀行为和电化学特性,通过扫描电镜、X射线物相分析等手段研究了原始涂层及腐蚀后的表面形貌和腐蚀产物的相结构,并对两种涂层的腐蚀机理进行了初步的探讨.随着盐雾时间的增加,纯锌涂层表面逐渐生成疏松多孔的胞状腐蚀产物层,主要腐蚀产物为Zn5(OH)8-Cl2H2O、ZnO和Zn5(CO3)2(OH)6,盐雾试验达到768h后腐蚀产物层局部区域发生龟裂.锌铝伪合金涂层表面生成致密的腐蚀产物层,主要为Zn5(OH)8C12H2O、Zn0.71A10.29(OH)2(CO3)0.145·xH2O及ZnAl2O4.电化学阻抗谱测试结果表明:随着盐雾时间的延长,两种涂层的电荷转移电阻均逐渐增大,但锌铝伪合金涂层的阻抗要明显大于纯锌涂层,表现出了更好的耐蚀性.  相似文献   

8.
在锌系低温磷化液中添加硫酸羟胺(HAS)以加快磷化反应速度.采用电化学方法测量了低温磷化过程φ-t曲线,并通过SEM,EDX研究了HAS对磷化膜形成过程的影响.结果表明:磷化过程可以分为3个阶段:第1和第2阶段主要是磷化液与基体腐蚀反应的阴极极化和去极化过程;第3阶段是晶粒的形核与长大.HAS具有极强的去极化能力,可加快磷化液与基体的腐蚀反应速度.添加HAS明显缩短了磷化各个阶段的时间,其中第1、第2和第3阶段分别缩短了50%,60%和50%;形成的磷化膜晶粒更细小致密,磷化膜中Zn2Fe(PO4)2含量略高.  相似文献   

9.
研制了中温锌钙系磷化液。考察了酸比、磷化温度、磷化时间、促进剂、添加剂等工艺参数对磷化膜耐蚀性的影响。通过正交实验,获得了一个磷化效果好的配方。  相似文献   

10.
含氯离子环境下锌铝伪合金涂层的耐蚀性及电化学特性   总被引:1,自引:0,他引:1  
采用盐雾试验和电化学阻抗谱测试技术研究了纯锌和锌铝伪合金涂层在含氯离子环境中的腐蚀行为和电化学特性,通过扫描电镜、X射线物相分析等手段研究了原始涂层及腐蚀后的表面形貌和腐蚀产物的相结构,并对两种涂层的腐蚀机理进行了初步的探讨.随着盐雾时间的增加,纯锌涂层表面逐渐生成疏松多孔的胞状腐蚀产物层,主要腐蚀产物为Zn5(OH)8-Cl2H2O、ZnO和Zn5(CO3)2(OH)6,盐雾试验达到768 h后腐蚀产物层局部区域发生龟裂.锌铝伪合金涂层表面生成致密的腐蚀产物层,主要为Zn5(OH)8Cl2H2O、Zn0.71Al0.29(OH)2(CO3)0.145.xH2O及ZnAl2O4.电化学阻抗谱测试结果表明:随着盐雾时间的延长,两种涂层的电荷转移电阻均逐渐增大,但锌铝伪合金涂层的阻抗要明显大于纯锌涂层,表现出了更好的耐蚀性.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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