991 resultados para XPS RESULTS


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对甲基丙烯酸-苯乙烯嵌段共聚物DMF溶液涂制膜(接着经过或不经其它溶剂的处理)的XPS研究表明,共聚物本体组成对膜的表面组成没有明显的影响。从DMF溶液直接涂膜时,按照两相模型,PMAA在表面的面积分数最大可达0.55。在用溶剂处理时,膜表面组成基本上决定于所用溶剂的溶解度参数,PMAA的表面面积分数按下列顺序降低:水>乙醇>环己烷>石油醚。

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本文采用VG ESCALAB MK-Ⅱ电子能谱仪对多层结构的薄膜Cu_2S-CdS太阳电池进行了X-光电子能谱、俄歇电子谱和深度分析。指出了电池表面的组成、结构和状态。由于制备工艺和处理方法的不同,电池表面和界面会发生变化,从而影响薄膜Cu_2S-CdS太阳电池的电性能和稳定性。本文为电池机理的研究提供了一些数据。

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用机械共混或溶液共混的方法,制备了γ-射线辐照交联的聚甲基乙烯基硅氧烷(PDMVS)-聚乙烯(PE)合金膜,并用 XPS,SEM 和接触角测量等研究其表面结构。XPS 结果表明,在深度~5nm 的膜表面有 PDMVS 链段的富集(只有一个例外),并得到接触角测量的支持。研究结果也表明,即使在~5nm 范围的表面有 PE 链段的富集,其最外层也存在一层很薄(~单分子层)的PDMVS,这一薄层就决定了接触角,并对膜功能有大的影响。

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用X射线光电子能谱(XPS)和二次离子质谱仪(SIMS)等表面分析方法对稀土-6063铝合金进行了研究,发现稀土铝合金的表面为金属铝和铝的氧化物两种形态。稀土及镁两者的协同作用,可以缓和铝合金的氧化程度。SIMS结果表明,加入适量稀土,可以抑制镁在稀土-6063铝合金的表面偏析作用。

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Yasuda等在用XPS研究离子体处理后的PTFE表面结构时,得到一个包络的C_(1s)峰。本文对此进行探讨。 PTFE膜先在蒸馏水中浸泡1小时,再用热异丙醇洗涤5分钟,然后用去离子水清洗三

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本文首次用X-光电子能谱(XPS)技术研究了H_2C_2O_4溶液中钛基的腐蚀行为,对Ti基片的表面和界面进行了XPS表征.实验结果表明:Ti基在80℃,10%的草酸溶液中腐蚀两小时,样品的表面只有Ti~0和TiO存在;经过四小时腐蚀的样品表面主要是TiO_2和少部分Ti~(2+).这与X-衍射分析认为有TiH_(1.042)的结构看法相符。同时,Ti0_2与表面涂层RuO_2都属金红石型结构,因而完全有可能形成牢固的金属阳极材料。

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由浓缩等摩尔稀土氯化物和甘氨酰替-L-亮氨酸水溶液制备了稀土与甘氨酰替-L-亮氨酸固体配合物。配合物组成为LnLCl_3·nH_2O(式中,L=甘氨酰替-L-亮氨酸;n=5,Ln=Eu;n=6,Ln=Tb,Ho和Tm)。用X射线光电子能谱研究了稀土与甘氨酰替-L-亮氨酸的配位作用。结果表明稀土与甘氨酰替-L-亮氨酸配合物中一些相关原子的电子结合能明显改变,并且发现铕配合物Eu_(3d),谱峰有强的伴峰,对上述伴峰产生机理亦进行了讨论。

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我们合成了稀土单酞菁配合物LnPcCl和LnPc(OAc)_2(Ln=Tb,Ho,Tm,Lu,Pc为酞菁根,OAc为乙酸根)。用XPS研究了它们的电子结构。结果指出,稀土酞菁配合物的化学键具有一定程度的共价性,其强度与电荷转移程度有关。L→Ln电荷转移不同于冠醚配合物,前者既有配位也含取代,后者纯系配位。且酞菁环系吸电子基团,电负性较高,故LnPc(OAc)_2中乙酸根的配位氧原子的Ols比Ln(OAc)_3的Ols结合能高。由于电荷转移程度与电负性、配位数等因素有关,LnPc(OAc)_2中Ln的配位数较高,LnPcCl中Cl的电负性较高,故LnPc(OAc)_2中Ln4d_(5/2)结合能低于LnPcCl。并讨论了配合物的分子组成及结构。

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XPS has extensively been applied to the study of polymers, in which a considerably important topic is the surface phase separations in block copolymers and blends. Copolymers (or blends) will produce a phase separation if their components are in-

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Microstructure of the glassy carbon surface modified with iron tetraphenyfporphyrin (FeTPP) by heat treatment has been studied by XPS,, DTA and TG. XPS spectra of Fe 2P_3\2 level in FeTPP and iron tetraphenylporphyriu/glassy carbon (FeTPP/GC) have shown that a bond can be formed between the glassy carbon surface and both the central metal iron ion and the macrocyclic, ligand, which loses its four phenyl groups during the beat treatment. The relationship between the surface mierostructure of FeTPP/GC and the...

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本文对聚偏氟乙烯,聚三氟氯乙烯,聚四氯乙烯及四氟乙烯-六氟丙烯共聚物的XPS谱进行了研究。通过对试样表面的不同清洁处理,得到了不同的谱图,表明试样表面污染物对XPS测定的干扰,特别是辐照样品。

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Zebrafish has been generally considered as an excellent model in case of drug screening, disease model establishment, and vertebrate embryonic development study. In this work, the ability of human cytomegalovirus immediate early promoter (CMV promoter)-driven short hairpin RNA (shRNA) expression vector to induce shRNA against VEGF gene in zebrafish was tested, and its effect on vascular development was assed, too. Using RT-qPCR, blood vessel staining, and in situ hybridization, we confirmed certain transcriptional activity and down regulation of gene expression by the vector. In situ hybridization analysis indicated selective inhibition of NRP1 expression in the VEGF gene loss of function model, which might imply in turn that VEGF could not only activate endothelial cells directly but also could contribute to stimulating angiogenesis in vivo by a mechanism that involved up-regulation of its cognate receptor expression in zebrafish. This contributed to a better understanding of molecular mechanisms of cardiovascular development. The system improved the success rate in making inducible knockdown and widened the possibilities for better therapeutic targets in zebrafish.

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To investigate the interaction between the tropical Pacific and China seas a variable-grid global ocean circulation model with fine grid[(1/6)degrees] covering the area from 20degreesS to 50degreesN and from 99degrees to 150degreesE is developed. Numerical computation of the annually cyclic circulation fields is performed. The results of the annual mean zonal currents and deep to abyssal western boundary currents in the equatorial Pacific Ocean are reported. The North Equatorial Current,the North Equatorial Countercurrent, the South Equatorial Current and the Equatorial Undercurrent are fairly well simulated. The model well reproduces the northward flowing abyssal western boundary current. From the model results a lower deep western boundary current east of the Bismarck-Solomon-New Hebrides Island chain at depths around 2 000 in has been found. The model results also show that the currents in the equatorial Pacific Ocean have multi-layer structures both in zonal currents and western boundary currents, indicating that the global ocean overturning thermohaline circulation appears of multi-layer pattern.