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1.
采用一次阳极氧化铝的方法分别在草酸、磷酸和柠檬酸溶液中制备了多孔阳极氧化铝膜,腐蚀掉铝片表面的氧化铝膜,铝片表面留下周期性纳米坑织构.利用扫描电子显微镜分析不同阳极氧化条件下铝膜的表面形貌,结果表明:铝片表面有序的六角阵列的纳米坑形成,坑的孔径大小随阳极氧化电压的升高而增大.铝片阳极氧化电压为300V,在浓度为4%柠檬酸中氧化2h,坑孔径达到785nm.使用光散射仪测量样品的光散射谱并研究样品对光的散射特性,散射光的强度随着散射角的增大而减小,铝膜表面纳米坑孔径越大对光散射越强.  相似文献   

2.
阳极氧化铝是将金属铝进行阳极氧化处理后,在其表面上形成的一层氧化膜,可对金属铝起到装饰和保护的作用.20世纪末人们发现,铝在适当的阳极氧化条件下可以制得具有纳米孔阵列的阳极氧化铝膜.随着纳米科学的蓬勃发展,纳米孔阵列阳极氧化铝膜由于其具有大的比表面积、高纵横比、大小均  相似文献   

3.
Ni纳米孔洞模板的制备   总被引:2,自引:0,他引:2  
使用纯度为99.5%的铝片,在空气中500℃退火5h,利用电化学阳极氧化手段将铝片制备成具有纳米级孔洞的氧化铝模板。用氧化铝模板作母板,在高真空下把甲基丙烯酸甲酯(MMA)注入到模板的柱形微孔内进行热聚合,制得聚甲基内烯酸甲酯(PMMA)纳米线阵列复合膜。把PMMA纳米线陈列复合膜浸入100g/L的NaOH溶液中,去掉氧化铝模板,得到PMMA纳米线陈列膜,利用化学自动催化方法将Ni沉积到PMMA纳米线阵列上,得到Ni纳米孔洞复合膜,最后用丙酮将PMMA溶解掉,得到具有纳米孔洞阵列的金属Ni模板。利用透射电子显微镜(TEM),电子衍射等测试手段对所制备模板进行了研究。TEM结果显示Ni模板的孔径约为45nm,孔心距为63nm左右,电子衍射结果显示模板是多晶材料。  相似文献   

4.
磷酸溶液中铝恒压阳极氧化的研究   总被引:1,自引:0,他引:1  
对铝在磷酸溶液中的恒压阳极氧化过程进行了研究,结果表明随着电解电压的升高,形成了氧化铝多孔膜的阻挡层增厚,多孔层的孔径和胞径均增加,其原因与离子迁移等密切相关。  相似文献   

5.
氧化铝纳米阵列模板的制备和研究   总被引:2,自引:0,他引:2  
 分别以硫酸和磷酸为电解液,用阳极氧化法在不同工艺下,制备纯度为99.999%,不同晶粒组织的纯铝箔基体上的氧化铝纳米阵列模板,得到5种孔径的纳米孔:10nm,20nm,30nm,60nm,100nm;用透射电镜和X射线衍射进行表征和结构分析,观察到了:阻挡层、趋于六边形的单元结构薄层和不同孔径、密度的纳米孔阵列,其结构为无定形,对这种自组织结构作了初步的生长过程分析.  相似文献   

6.
以草酸为电解液,采用两步阳极氧化工艺,自组装生长纳米孔氧化铝膜,在一个微米范围内获得六方纳米孔阵列.采用原子力显微镜观察不同氧化阶段的氧化铝膜表面的形貌变化和相应阻挡层的结构信息,并利用X射线衍射分析氧化铝膜的结构.研究结果表明,通过改变电解液浓度、氧化电压和氧化时间可有效控制孔的形核和生长,氧化铝膜呈非晶态结构.  相似文献   

7.
通过两步阳极氧化法由铝片制得高度有序的多孔氧化铝膜(PAA),采用高电压瞬时脉冲法分离出完整而独立的多通孔氧化铝模板。用SEM对其表面进行分析,结果表明用瞬时电压脉冲法可以很好地分离出完整的通孔膜,且膜质量很高。孔直径为40~50nm,孔间距为90~105nm,膜厚度为25μm左右,孔密度高达1.34×10~(10)个/cm~2。通过4次阳极氧化的时间电流密度曲线对比,表明两步阳极氧化可以刺得高度有序的PAA膜。  相似文献   

8.
报道一种用于快速、无损检测阳极氧化铝(Anodic Aluminum Oxide,AAO)阻挡层的光谱方法.通过两步阳极氧化法制备了孔径均一,孔道相互平行的纳米孔氧化铝薄膜;用紫外-可见-近红外(UV-VIS-NIR)光谱仪研究了不同阻挡层厚度的样品的透射光谱;结果表明,在可见-近红外光范围内,有阻挡层的纳米孔氧化铝薄膜的透射光谱出现振荡波,而且其波峰(谷)的数目与AAO的阻挡层厚度成线性关系,其线性相关系数为0.99979.这一发现为快速无损检测AAO阻挡层厚度提供了一种简单而高效的方法.  相似文献   

9.
利用纳米多孔阳极氧化铝膜的纳米孔阵列,实现了浓度梯度差发电.通过纳米孔阵列两侧浓度梯度差的改变,分析了输出功率与浓度梯度差的关系,并报道了短路电流和开路电压随时间的演化规律.基于纳米孔与输运离子的静电相互作用原理,我们发现平均孔径约25 nm的纳米多孔阳极氧化铝膜对离子输运具有选择透过性.进一步,通过引入纳米颗粒对纳米多孔阳极氧化铝膜进行修饰,输出功率提高了近18倍,而且纳米孔阵列的离子选择性发生变化.我们初步认为这可能与纳米颗粒与纳米孔阵列的复合结构的离子选择性相关.  相似文献   

10.
通过两步阳极氧化法由铝片制得高度有序的多孔氧化铝膜(PAA),采用高电压瞬时脉冲法分离出完整而独立的多通孔氧化铝模板。用SEM对其表面进行分析,结果表明用瞬时电压脉冲法可以很好地分离出完整的通孔膜,且膜质量很高。孔直径为4050nm,孔间距为9050nm,孔间距为90105nm,膜厚度为25μm左右,孔密度高达1.34×10105nm,膜厚度为25μm左右,孔密度高达1.34×10(10)个/cm(10)个/cm2。通过4次阳极氧化的时间电流密度曲线对比,表明两步阳极氧化可以刺得高度有序的PAA膜。  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.
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   

20.
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   

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