常温时添加剂对Ce-Mn转化膜的影响

为了提高常温下Ce-Mn转化膜在铝合金表面的成膜速度和耐腐蚀性能,在室温、pH=2的Ce(NO3)3和KMnO4的混合溶液中分别添加H3BO3、Zr(SO4)2、NaF、HF、NaBF4和Na2ZrF66种添加剂,研究添加剂对Ce-Mn转化膜的影响.通过光学显微镜、涡流测厚仪、点滴腐蚀法、Tafel极化曲线和交流阻抗等研究了膜的金相组织、厚度及耐腐蚀性能等;同时,通过SEM和EDS研究了氟化钠对膜的形貌和成分的影响.结果表明:氟化钠是较佳的常温成膜促进剂,常温下9 min就能成膜,相对于无添加剂的Ce-Mn转化膜,膜厚增加2.3倍,耐点滴腐蚀时间延长2.0倍,腐蚀电流密度降低至原来的1/3,膜电阻提高3.9倍:添加NaF后膜的铈含量从5.14%提高到8.59%,锰含量从7.70%提高到14.42%.     

一步法合成耐久性水基超疏水TiO2/DTMS涂层

为制备具有优异自清洁功能的耐久性水基超疏水涂层，以十二烷基三甲氧基硅烷(n-dodecyltrimethoxysilane, DTMS)为有机改性物，通过一步法在纳米TiO₂表面嫁接长链烷基官能团得到超疏水TiO₂/DTMS涂层。分析了TiO₂涂层及TiO₂/DTMS涂层的表面润湿性、形貌和化学组成，并对所得超疏水TiO₂/DTMS涂层的自清洁性能、机械及化学稳定性进行了测试。结果表明：超疏水TiO₂/DTMS涂层表面水接触角(water contact angle, WCA)达到159°；以亚甲基蓝粉末作模拟污染物，涂覆有超疏水TiO₂/DTMS涂层的玻璃具有优异的自清洁性能；经机械磨损(10 min)、酸碱液(pH=1、3、5、7、9、11、13)浸泡、高低温(−20、30、60、90、120、150 ℃)处理后超疏水TiO₂/DTMS涂层的WCA仍大于150°，表明其具有优异的机械和化学稳定性，可用于室外防污，如建筑物外墙、玻璃、太阳能电池板等。     

堆焊Mo-Cr-Fe-B合金覆层的组织及性能研究

采用自制Mo-Cr-Fe-B系药芯焊丝通过堆焊法在Q235钢基体表面制备覆层。借助光学显微镜、SEM、XRD、EDS、显微硬度计、磨损试验机等对覆层及结合界面的组织结构、物相、硬度分布及耐磨性进行了表征与分析,并研究了覆层堆焊成型的反应过程。结果表明,覆层主要由Mo_2FeB_2、M_3B_2(M:Mo、Cr、Fe)、Fe_2B、Fe(Cr、Mo)等相组成,覆层与钢基体结合良好,在覆层-钢基体界面结合处有元素的扩散,覆层硬度最高可达980HV0.5且耐磨性良好。     

Ni_3Si涂层对Ti_6Al_4V合金抗NaCl/O_2/H_2O(g)协同腐蚀性能的影响

研究了磁控溅射法制备的Ni3Si涂层对Ti6Al4V合金在600℃下,抗NaCl/氧气/水蒸气协同腐蚀性能的影响.结果表明,在材料遭受腐蚀的过程中,Ni3Si涂层有效地改善了Ti6Al4V合金抗NaCl/氧气/水蒸气综合腐蚀的能力;而无涂层试样遭受了严重的腐蚀,不仅发生了内氧化,而且有大量的腐蚀产物脱落.利用带能谱的扫描电镜、X射线衍射、电子探针和表面光电子能谱对样品的腐蚀行为进行了分析,并讨论了涂层抗腐蚀的机理.     

Effects of calcination temperature on the structure and adsorption performance of Ce-Mn/AC materials

Activated carbon-supported bimetallic cerium-manganese (Ce-Mn/AC) materials were prepared by impregnation method to study the effect of calcination temperature on the structure and adsorption performance of absorbents. The obtained materials were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM), N₂ adsorption-desorption isotherm, Fourier transformed infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). As the results showed, the diffraction peaks of CeO₂ decreased and even disappeared; Mn species were transformed from Mn₃O₄ to Mn₂O₃ on the surface of Ce-Mn/AC; the BET specific surface area increased first and then decreased on the elevating calcination temperature; the number of acid functions of AC was reduced after being modified by cerium and manganese. All these changes were directly attributed to the synergistic effects between MnO_x and CeO₂. AC800 exhibited the best phenol adsorption capacity. The adsorption mechanism of phenol on Ce-Mn/AC was discussed with hydrophilic (hydrophobic) interaction and hard and soft acid-base theory.     

不同形貌LaBO_3型钙钛矿的制备及其催化H_2O_2分解反应性能

采用柠檬酸络合法制备了La BO3(B=Fe,Co,Ni)钙钛矿催化剂,通过X-射线粉末衍射(XRD)、傅立叶-红外光谱(FT-IR)、透射电镜(TEM)、X-射线光电子能谱(XPS)等对催化剂进行了表征,在室温下测定了其对H2O2的催化分解能力.结果表明:催化分解能力依次为La Ni O3>La Co O3>La Fe O3,说明Ni较Co和Fe能更好地分解H2O2.通过改变La Fe O3催化剂的形貌也能提高催化剂性能,如多孔状La Fe O3较负载在SBA-15上的La Fe O3具有更好的催化分解活性.     

Surface interactions of MoO3/ α-Fe2O3 system

α-Fe₂O₃ -supported molybdena catalysts have been prepared by heating a mixture of MoO₃ and α-Fe₂O₃. XRD, XPS, LRS, TG-DTA and Mössbauer spectroscopy were used to characterize the interactions between MoO₃ and α-Fe₂O₃. The dispersion capacity of MoO₃ on the surface of α-Fe₂O₃ determined by XRD and XPS was 0.8 mmol/100m² α-Fe₂O₃ in the samples calcined at 420 . For the sample with low MoO₃ loading, LRS and FT-IR results showed that Mo⁶⁺ ions were located in the tetrahedral vacant sites on the surface of α-Fe₂O₃, signed as Mo- . The amount of Mo-II species, formed by Mo6+ ions incorporated into the octahedral vacant sites, increased with the MoO₃ loading. Based on the assumption that the (001) plane of α-Fe₂O₃ is preferentially exposed, almost all the Mo⁶⁺ ions of the dispersed molybdena species existed at the surface octahedral sites for the sample with MoO₃ loading close or beyond the dispersion capacity, and formed the Mo-II species. In this case, the capping O^2- ions linking with the incorporated Mo⁶⁺ ions formed a surface epitaxial structure, which was in good agreement with the results predicted by the incorporation model proposed previously. XRD and Mössbauer spectroscopy of the MoO₃ α-Fe₂O₃ samples calcined at different temperatures showed that the calcination temperature could strongly influence the interaction extent: ( i) at 420 , MoO₃ dispersed on the surface of α-Fe₂O₃ and formed surface Mo species; (ii ) at 500 , MoO₃ reacted with the bulk of α-Fe₂O₃ and formed Fe₂(MoO₄)₃ compound.     

三聚氰胺热解产物的特性分析

以有机物三聚氰胺为初始原料, 在真空条件下使其热解（1 000 K）. 采用X射线衍射（XRD）、 透射电子显微镜（TEM）、 X射线光电子能谱(XPS)、 化学元素分析（EA）和傅里叶红外光谱(FT-IR) 分析样品的形貌、 成分和结构. 结果表明, 在真空条件下, 三聚氰胺全部分解, 分解产物为片层石墨相C₃N₄.      

烟火药剂中三种常用氧化剂的太赫兹谱研究

为了探索烟火药剂中常用氧化剂的太赫兹谱,利用量子化学模拟计算烟火药剂中常用氧化剂氯酸钾、高氯酸钾和硝酸钾的太赫兹频率吸收范围和特征吸收峰.并用太赫兹时域光谱系统实际测量得到了这些氧化剂以及含高氯酸钾烟火药剂在0.2～2.5THz频谱范围内的吸收光谱峰值位置.氯酸钾在0.2～2.5THz波段的特征吸收峰为2.4THz,纯高氯酸钾和含高氯酸钾混合烟火药剂都在2.0THz和2.2THz处分别具有明显的特征吸收峰,硝酸钾的特征吸收峰位于1.8THz和2.3THz处.理论计算与实验测量结果对比表明,三种氧化剂在0.2～2.5THz波段的特征吸收峰有较好的一致性.     

Synthesis and modification of well-ordered layered cathode oxide LiNi<Subscript>2/3</Subscript>Mn<Subscript>1/3</Subscript>O<Subscript>2</Subscript>

Oxalic-acid-based co-precipitation method was employed to prepare LiNi_2/3Mn_1/3O₂ sample with a high-ordered structure. Li⁺, Ni²⁺ and Mn²⁺ acetates were used as starting materials. The influence of the amount of lithium source in the starting materials on Li⁺ content, disorder of Li⁺-Ni²⁺ ions, and electrochemical performance has been investigated. Rietveld refinement shows that the sample prepared with 20% excess Li-source in the starting materials exhibits a perfect ordered structure. A specific discharge capacity is as high as 172 mAh/g at C/20 in the voltage range of 4.35–2.7 V. However, the cyclability is not satisfactory: about 25.3% fade in capacity was observed over 50 cycles. Chemically stable SiO2 was coated on the surface of LiNi_2/3Mn_1/3O₂ particles. A significant improvement in cyclability was attained with 3 wt% SiO2 coating, which is ascribable to the protection of LiNi_2/3Mn_1/3O₂ particles from being dissolved into the electrolyte.     

Preparation of CuInSe2 thin films by four-step process

A simple process for the deposition of CulnSe₂ thin films was described. The CulnSe₂ compound was prepared by selenization of Cu-In alloy precursors, which were electrodeposited at a constant current. The selenized precursors were compacted and then annealed. The films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results indicate that single-phase CulnSe₂ is formed at 250℃ and its crystallinity of this phase is improved as the annealing temperature rises. The losses of In occur in selenization process. The dense CulnSe₂ film with comparatively smooth surface can be obtained by compaction under the pressure of 200 MPa.     

用于邻苯基苯酚合成的Pt-K/Al2O3脱氢催化剂(Ⅱ):催化剂失活机制

采用热重-差热分析(TG-DTA)、元素分析、氢氧滴定(HOT)、扫描电镜能谱分析(SEM-EDS)、透射电镜(TEM)等对Pt-K催化剂可能的失活机制进行研究。结果表明:积碳并非Pt-K催化剂失活的主要原因;脱氢催化剂上铂颗粒的尺寸在运转过程中没有明显的增大,即铂中心烧结也不是催化剂失活的主要原因;Pt-K催化剂在运转过程中铂分散度明显下降而且无法通过再生恢复;Pt-K/Al2O3催化剂的失活极有可能源自催化剂运转过程中钾物种对铂中心的过度覆盖作用。     

纳米Al2O3颗粒对Cu-Al2O3性能的影响

采用溶胶-凝胶法制备纳米Al₂O₃颗粒,通过粉末冶金法制备氧化铝铜（Cu-Al₂O₃）。采用X射线光电子能谱仪、扫描电子显微镜、洛氏硬度仪和涡流计分别测试了Cu-Al₂O₃的结合能、微观组织、硬度和导电率。结果表明：随Al₂O₃颗粒含量的增加,Cu-Al₂O₃的硬度先升高后降低,当Al₂O₃颗粒的质量分数达到0.084%时,Cu-Al₂O₃的硬度达到最大值75.73（HRB）。Cu-Al₂O₃的导电率随着Al₂O₃颗粒含量的增加逐渐下降。Al₂O₃颗粒的质量分数为0.084%时为最佳值,Cu-Al₂O₃的硬度达到最大值,导电率达到69.1% IACS。     

纳米Fe3O4覆盖对沉积物-水界面钴和镍的吸附试验研究

为揭示纳米材料原位覆盖对表层沉积物重金属的影响规律,开展室内培养原位沉积物柱试验,利用微界面分析技术、高分辨率平衡式间隙水采集技术（HR-Peeper）和薄膜扩散梯度技术（DGT）,探究纳米Fe₃O₄原位覆盖对表层沉积物中Co、Ni释放的影响机制。试验结果表明:在纳米Fe₃O₄覆盖下沉积物pH值较对照组逐渐增大,Eh值先减小后增大;纳米Fe₃O₄覆盖可有效吸附间隙水中的溶解态Co和Ni,间隙水中的溶解态Co和Ni最大有效吸附率分别为27.07%及26.42%,有效影响深度分别为30 mm和10 mm;纳米Fe₃O₄覆盖有效抑制了沉积物中有效态Co和Ni向间隙水和上覆水扩散,沉积物中有效态Co和Ni含量分别降低了50.26%和15.31%。     

TiO_2-SnO_2异质结纳米棒催化剂高效光降解甲基橙

采用水热法合成SnO_2-TiO_2异质结纳米棒光催化剂,该材料具有独特的纳米棒和异质结结构,可有效阻止光生电子和空穴的复合,通过光电流、X射线光电子能谱(XPS)、X射线衍射(XRD)、透射电子显微镜(TEM)等表征手段证明其异质结功效.该材料作为光催化剂,使用时能大幅提升紫外光降解甲基橙(MO)的效率.     

Y_2O_3/GeO_2/环氧树脂基辐射防护材料的制备及性能研究

用表面处理稀土氧化物Y_2O_3,GeO_2的方法制备了Y_2O_3/GeO_2/环氧树脂辐射防护材料.采用X射线衍射仪(XRD)研究了材料的微观结构;用多道γ谱仪测试并分析了材料的辐射防护能力.结果表明,制得的材料中的Y_2O_3和GeO_2粒子并未与环氧树脂发生键和反应,Y_2O_3与GeO_2粉末的加入明显提升了材料防护射线的效果.     

Decoration of C60 nanorods with nickel and their magnetic properties

We studied the coating of C60 nanorods with nickel by electroless plating method and investigated their magnetic properties. The morphology and structure of the nickel layer coated on C60 nanorods were characterized by transmission electron microscopy （TEM）, energy-dispersive X-ray spectroscopy （EDX）, X-ray diffraction （XRD） and Raman spectroscopy. The coated nickel is in the form of nano-sized crystals and becomes a continuous layer as reaction time increases. The hysteresis loop shows a super paramagnetic characteristic similar to that of nanometer-sized nickel particle. These results suggest that the average size of nickel particles on C60 rods is below 10 nm. Our study has shown that electroless plating is an efficient and simple method for coating C60 nanorods with nickel.     

纳米Fe2O3-Al2O3复合材料的制备

采用溶胶-凝胶表面包覆法制备了纳米Fe₂O₃-Al₂ O₃复合材料, 利用X射线衍射和透射电镜对样品的物相、 粒度和形貌进行了研 究. 结果表明, α-Fe₂O₃掺杂降低了Al₂O₃相变温度, 在900 ℃可以得到稳定的α-Al₂O₃相.     

水热体系下二氧化钛与氧化石墨烯复合纳米晶的合成

 200 ℃下四方结构的二氧化钛(TiO2)与氧化石墨烯(GO)复合纳米晶在一个装有适量钛酸四丁酯、无水乙醇、氧化石墨烯和蒸馏水的密闭的水热釜中加热12 h后被制备。X射线粉末衍射仪（XRD)、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等一系列分析仪器被运用来揭示二氧化钛与氧化石墨烯复合纳米晶是由粒径大约160 nm的四方结构的二氧化钛纳米晶与氧化石墨烯复合而成,通过紫外吸收对其光学性能进行了必要的测试。
     

Effect of La2O3 on microstructure, mechanical and tribological properties of Ni-W coatings

In this paper, a Ni-W-La2O3 composite coating was prepared by the electrodeposition method. Microhardness tester and environmental scanning electron microscope equipped energy dispersive spectroscopy were employed to investigate the microhardness and the surface morphology of the composite coatings respectively, and the high temperature friction behavior and corrosion resistance of the coatings against molten glass were investigated by using a high temperature tribometer. The results show that La2O3 can refine the microstructure effectively, and make the element distribution uniform, which leads to the increase of average microhardness. La2O3 particulates can reduce the friction coefficient between the composite coating and glass during the sliding process at about 973 K largely, and the corrosion resistance of the La2O3 added Ni-W coatings is effectively improved compared with that of the non-added one, furthermore the mechanism of friction-reducing and anti-corrosion is also discussed.