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1.
研究在低温熔融盐体系中于不同基底上电沉积单一稀土金属镧(La)。经X-射线能谱仪测定,在镍片基底上沉积的La的质量分数为100%,铜片基底上沉积的La质量分数为72.84%;在镍铁合金灯丝上沉积得到La-Ni合金薄膜,其中La的质量分数为50.02%,Ni的质量分数为2.48%。经扫描电子显微镜观察,所得的沉积膜为均匀、光滑、致密的黑色沉积薄膜。经X-射线衍射仪分析,镧在不同基底上沉积所得的沉积膜为不同晶型,以镍片为基底得到的单质镧为α-六方晶型;以铜片为基底得到的单质镧为面心立方晶;均与基底晶型相匹配。在镍铁合金灯丝上电沉积所得的La-Ni合金薄膜致密均匀,在无水乙醇中久浸而不脱落,并呈现强磁性。  相似文献   

2.
Pt/KL沸石在异丙醇分解反应中具有很高的脱氢活性,而Pt/HL沸石具有明显的缺电子性,在此反应中难以显示出脱氢活性,通过加氢作用,可使沸石的酸位免受积炭覆盖,从而可增强Pt/HL沸石的酸性催化作用。  相似文献   

3.
甲酸在钼青铜修饰铂电极上的催化氧化   总被引:2,自引:0,他引:2  
应用循环伏安法和双电位阶跃法研究了不同浓度硫酸中钼酸盐在多晶铂电极上的电化学行为 .在硫酸溶液中 ,当电位负向扫描时 ,钼酸盐即于铂电极上还原形成钼青铜 ,吸附在电极表面 ;电位正向扫描时钼青铜将再被氧化 ,氧化机理受硫酸浓度的影响 .铂电极因钼酸盐的还原和钼青铜的氧化而得到修饰 .在硫酸钠溶液中以此修饰的铂电极对甲酸氧化有明显的催化作用 ,其氧化峰电流接近未修饰铂电极上的 2倍 .钼青铜对铂的不完全修饰或过分修饰均会减弱甲酸氧化的催化作用  相似文献   

4.
Sorption of nonylphenol on Na-montmorillonite was studied by batch experiment and compared with that on -SiO2, -Al2O3 and gibbsite. It was found that sorption of nonylphenol on Na-montmorillonite reached the equilibrium state within 24 h, and that the interlayer width of Na-montmorillonite did not change before and after the sorption. These suggest that nonylphenol was sorbed on the outer surface of Na-montmorillonite. Sorption isotherms of nonylphenol on Na-montmorillonite, -SiO2, -Al2O3 and gibbsite were studied. Sorption amount of nonylphenol on the surface of octahedral sheets of Na-montmorillonite was found to be identical to that of gibbsite. On the other hand, sorption amount on -Al2O3 was smaller, and that on -SiO2 was fairly few. Dependence of sorption onto Na-montmorillonite on pH and ionic strength was also examined. Sorption amount was found to increase monotonously with pH. Sorption amount decreased with ionic strength in the low ionic strength region, reached to a minimum and then increased with ionic strength. These results might suggest that nonylphenol was sorbed on the broken-edges of octahedral alumina sheets of Na-montmorillonite.  相似文献   

5.
大孔吸附树脂对邻甲酚的吸附行为研究   总被引:14,自引:0,他引:14  
研究了大孔吸附树脂NDA—909吸附水溶液中邻甲酚的热力学特征,并与Amberlite XAD—4树脂进行了比较.通过吸附动力学实验,初步探讨了初始温度对吸附过程的影响。结果表明,NDA—909对邻甲酚的吸附符合Freundlich经验公式,表现为放热的物理吸附过程.此外吸附速率受颗粒内扩散和其它类型扩散的共同控制。  相似文献   

6.
碳化钨在对硝基苯酚电还原过程中的电催化行为   总被引:4,自引:0,他引:4  
以碳化钨(WC)粉末为电催化材料制成了碳化钨粉末微电极(WC-PME). 采用循环伏安和线性扫描等方法研究了酸性溶液中对硝基苯酚(PNP)在WC-PME上的电还原行为. 研究表明, 在相同测试条件下, PNP在WC-PME上电还原的电位比Cu-Hg微电极正得多;WC-PME对氢具有较强的吸附能力, 有利于有机物的电还原反应. PNP在WC-PME上和Pt微电极上的还原电位相近, 但在WC-PME上的峰电流比在Pt微电极上高5倍多, 这主要与WC粉末的结构形貌有关.  相似文献   

7.
以膨胀珍珠岩为载体的漂浮型TiO2光催化剂降解水面浮油   总被引:15,自引:0,他引:15  
 以膨胀珍珠岩为载体制备了漂浮负载型TiO2光催化剂,并对制备催化剂的工艺条件及水面浮油的光催化降解过程进行了初步研究.通过扫描电镜分析及BET比表面积和TiO2负载量测定,对影响负载型光催化剂漂浮性能的因素进行了分析.以癸烷为水面模拟污染物,考察了其在日光照射下的降解效率.用气相色谱法测定了经不同时间光照后癸烷的残留量,经7h光照后能降解癸烷95%以上.实验结果表明,以膨胀珍珠岩为载体,可制得能长期漂浮于水面的负载型TiO2光催化剂,通过浮油富集和光催化降解机制可对水面浮油进行有效的治理.  相似文献   

8.
研究了一种具有可逆响应的蛋白质生物传感器。敏感层由丙烯酰胺荧光素固定于硅烷化的平面波导上形成,然后装配在自制的流通池中并用光导纤维连入荧光分光光度计,结果发现牛血清白蛋白(BSA)对此敏感膜有明显的荧光增强反应,在0.4-20μmol/L范围内敏感膜的荧光增强度与BSA的浓度呈线性关系,检测下限为0.1μmol/L。并且此传感器无需特殊的试剂及其进行再生,等电点不同的蛋白质引起的荧光增强程度也不同,常见的金属离子对测定无影响,但重金属离子对测量有较大的影响。对传感器的响应机理也进行了多方面的分析,推测传感器的响应可能是由蛋白质上的氨基与丙烯酰胺荧光素上的羧基发生反应引起的。  相似文献   

9.
两种吸附树脂对4B酸吸附行为的比较研究   总被引:4,自引:0,他引:4  
研究了新型复合功能吸附树脂NDA-99和超高交联大孔吸附树脂JX-101对水溶液中4B酸(对甲苯胺-2-磺酸)的静态吸附行为和热力学特性,结果表明,NDA-99树脂对4B酸的吸附量明显大于JX-101树脂,两种树脂对4B酸的吸附均符合Freundlich吸附等温方程.其中,JX-101对4B酸的吸附属于物理吸附:NDA-99由于树脂表面存在弱碱性官能团,对4B酸的吸附表现为物理吸附和化学络合协同作用。  相似文献   

10.
《Analytical letters》2012,45(14):2761-2774
ABSTRACT

The high-performance liquid chromatographic behavior of some bases and nucleosides was studied on a new reversed-phase stationary phase, alkylphosphonate-modified magnesia-zirconia. The effect of mobile phase variable such as methanol content, ionic strength and pH on their behavior was investigated. It was found that the retention behavior of the bases and nucleosides on the new stationary phase is similar to that on ODS stationary phase. The retention mechanism on the new stationary phase was also discussed. The separation of some bases and nucleosides was accomplished on the new stationary phase.  相似文献   

11.
摘要用原位红外和脉冲实验研究了甲醇在氧化锌表面的吸附行为. FTIR结果表明, 甲醇吸附于氧化锌上易生成甲氧基, 且其生成量随着吸附温度的提高而增加. 进一步的研究结果表明, 甲氧基是由甲醇同氧化锌表面的羟基反应生成的, 将其暴露于水蒸汽中后很快消失. 脉冲实验发现, 氧化锌上脉冲甲醇时产生水, 再脉冲水则产生甲醇. 因此甲醇在氧化锌表面吸附生成甲氧基和水的反应是可逆的.  相似文献   

12.
Summary The enzyme amyloglucosidase was immobilized on oxidized DIOL silica and used to separate enantiomers of amino alcohols. The influence of pore size on enantioselectivity was studied and an optimum in the separation factors was found using 500 ? DIOL silica as the starting material. About twice the amount of the protein could be immobilized on the 500 ? DIOL silica material as on the 300 and 1000 ? materials. The immobilization procedure was easy to reproduce and no significant difference in the chromatographic behavior was observed between two amyloglucosidase columns produced in-house. The effect of solute structure on enantioselective retention was studied using a set of 10 closely related amino alcohols. High separation factors (α>2) were obtained and the efficiency of the amyloglucosidase columns was greater than 25 000 plates/m based on the last eluted enantiomer.  相似文献   

13.
Chiralcel OD-RH手性柱拆分安息香对映体的热力学研究   总被引:1,自引:0,他引:1  
利用Chiralcel OD-H手性柱拆分外消旋安息香化合物制备单一对映体标样,并对其进行圆二色光谱表征。在此基础上,采用甲醇、乙醇、乙腈为流动相考察了安息香在Chiralcel OD-RH柱上的色谱拆分行为和热力学特性。结果表明:以纯甲醇为洗脱液时,(S)-构型先出峰,安息香的拆分过程为焓控;以纯乙醇为洗脱液时,(R)-构型先出峰,拆分过程为熵控;而以纯乙腈为洗脱液时,虽然也是(R)-构型先出峰,但熵和焓对拆分均有贡献。文中还对比了安息香在Chiralcel OD-H柱的拆分性能。  相似文献   

14.
A kind of organic–inorganic composite film with biomimetic superhydrophobic performance was prepared on several metals including steel, aluminum, and copper. The organic matrix was ultrahigh‐molecular‐weight polyethylene (UHMWPE), and the inorganic filler was nanosilica. Scanning electron microscope observation indicated addition of nanosilica greatly changed the topography of the UHMWPE film. Special convexities were formed on the surfaces of the composite films, which made the composite films rougher than that of pure UHMWPE film. The nanosilica randomly scattered on the surface of the convexities and formed hierarchical structure similar to that of some plant leaves with superhydrophobic characteristics. Interestingly, it was found that there were remarkable differences between the sliding angles (SA) of water droplet on the composite films on different metals although the contact angles (CA) of water droplet on these films were quite close. The CA on the composite films on steel was about 157°, and the SA was larger than 90°, which demonstrated obvious superhydrophobic and sticky characteristic. But to the films on aluminum and copper, the CAs on them were larger than 160° and the SAs were between 3° and 4°, which meant excellent superhydrophobic and roll‐off performance. Scanning electron microscope observation indicated that there were some micro‐orifices in the film on steel and these micro‐orifices were connected to some extent. It was believed that these micro‐orifices provided capillary force and restrained sliding of water droplet. A sticky model based on capillary mechanism was proposed. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

15.
Adsorption behavior of urea on silver electrode and the influence of thiourea on its adsorption in sulphuric acid solution were investigated by polarization curves and Surface Enhanced Raman Spectroscopy. Urea was found to undergo a condensation reaction on roughened silver electrode. Biuret was the condensation compound, and was adsorbed in the protonated form on the silver surface. Obvious synergistic mechanism between thiourea and protonated biuret was proposed.  相似文献   

16.
化学聚合法制备电容器用聚苯胺   总被引:1,自引:0,他引:1  
采用化学聚合法制备电容器用聚苯胺,研究了不同的掺杂剂对聚苯胺(Pan)电导率的影响,并利用TGA、FT-IR等分析手段对聚苯胺的热老化性质进行研究,研究了乳液法产物的二次掺杂现象,并把萃取液涂布于铝箔表面制成固体电容器,结果表明这种聚苯胺应用于固体电容器是可行的。  相似文献   

17.
张茂峰  杨朝晖  丛海林  曹维孝 《化学学报》2004,62(21):2187-2190
组装于硅片或玻璃片基片上的重氮树脂(DR)单层膜,吸附SnCl2,Pd催化剂后,通过无电沉积的方法,在这些基片上制备了铜膜.对得到的铜膜进行了SEM,XRD表征.通过选择性无电沉积,成功地制备了铜膜图像.  相似文献   

18.
采用氩弧熔炼和热处理方法获得PtSb有序金属间化合物材料. 用循环伏安和计时电流技术进行电化学性能测试. 在含有0. 25 mol•L-1 CH3CH2OH的硫酸溶液中, 通过对乙醇电氧化的起始电位和电流密度大小的比较发现, PtSb金属间化合物具有良好的催化乙醇氧化性能. 利用XRD和XPS技术分析了晶体结构和电子结构. 采用不同扫描速率下的循环伏安技术得到乙醇氧化的电子交换系数(α), 发现C2H5OH在PtSb催化剂表面上反应时的α远远大于在Pt电极表面的.  相似文献   

19.
The objective of this study was to investigate the adsorption of fibronectin on titanium (Ti) surfaces and the effect of pre-adsorbed fibronectin on osteoblast precursor cell attachment in vitro. Two different concentrations of bovine fibronectin were used in this study. Protein adsorption on Ti surfaces was analyzed using the micro bicinchoninic acid (BCA) protein assay. Cell concentration on Ti and fibronectin pre-adsorbed Ti surfaces after 3 h incubation was analyzed using the Vybrant™ cell adhesion assay. Cell morphology on Ti and fibronectin pre-adsorbed Ti surfaces was observed using scanning electron microscopy (SEM). After 180 min incubation, maximum adsorption of bovine fibronectin on Ti surfaces was observed. Fibronectin adsorption on Ti surfaces was observed to be significantly dependent on the initial concentration and the amount of incubation time. In the presence of 1 mg/ml fibronectin pre-adsorbed on Ti surfaces after 15 min, osteoblast precursor cell attachment on Ti surfaces was observed to be enhanced compared with control Ti surfaces, Ti surfaces pre-adsorbed with 1 mg/ml fibronectin for 180 min, and Ti surfaces pre-adsorbed with 0.1 mg/ml fibronectin for 15 and 180 min. No significant difference in cell attachment was observed between control Ti surfaces, Ti surfaces pre-adsorbed with fibronectin for 180 min, and Ti surfaces pre-adsorbed with 0.1 mg/ml fibronectin for 15 and 180 min. In addition, no differences in cell morphology of the attached osteoblast precursor cells on control Ti surfaces and Ti surfaces pre-adsorbed with fibronectin were observed in this study. It was concluded that an optimum concentration of adsorbed fibronectin on Ti surfaces plays an important role in governing cell attachment.  相似文献   

20.
A calibration model for in-line API determination was developed based on Raman spectra collected during hot-melt extrusion. This predictive model was validated by calculating the accuracy profile based on the analysis results of validation experiments. Furthermore, based on the data of the accuracy profile, the measurement uncertainty was determined. Finally, the robustness of the model was evaluated.  相似文献   

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