黄铁矿表面改性产物的XRD谱研究

用Ｘ射线衍射技术（ＸＲＤ）分析了重庆中梁山矿的煤系黄铁矿不同氧化程度及改性后的表面结构。根据改性前后的ＸＲＤ数据，推导出不同电化学条件下的表面产物，为浮选分离煤系黄铁矿提供理论依据。     

负载型Fe－Co双金属簇催化剂的谱学表征

本文利用ＸＰＳ、Ｉｎ－ｓｉｔｕＩＲ、Ｍｏｓｓｂａｕｅｒ和ＥＰＲ谱对负载型Ｆｅ－Ｃｏ双金属簇催化剂在负载前后，反应前后催化剂表面状态的变化和表面原子的相互作用进行了研究。实验表明，负载后双金属簇中的ＣｏＦｅ＿３金属簇骨架与担体的表面原子发生了强相互作用。在反应条件下，簇骨架发生了断裂，在担体表面形成金属碎片，并成为ＣＯ加氢反应的催化活性中心。     

负载型Fe—Col双金属簇催化剂的谱学表征

本文利用ＸＰＳ、Ｉｎ－ｓｉｔｕ ＩＲ、Ｍｏｓｓｂａｕｅｒ和ＥＲＲ谱对负载型Ｆｅ－Ｃｏ双金属簇催化剂在负载前后，反应前后催化剂表面状态的变化和表面原子的相互作用进行了研究。实验表明，负载后双金属簇中的ＣｏＦｅ３金属簇骨架与担体的表面原子发生了强相互作用。在反应条件下，簇骨架发生了断裂，在担体表面形成金属碎片，并成为ＣＯ加氢反应的催化活性中心。     

添加剂对煤气化过程中石灰石固硫行为的影响

为了研究添加剂在石灰石固硫过程中的作用，选择了一系列添加剂对含不同氧化镁的二种石灰石进行改性，采用ＸＲＤ、ＸＰＳ及ＤＴＡＴＧ技术，研究了石灰石改性前后及煤气化过程中固硫反应前后钙基固硫剂的结构、表面组成及热性能，并与固硫特性相关联。实验得出：无机氯化物及一系列钠盐对石灰石的固硫能力具有不同程度的影响，其中氯化钠的促进作用最明显，其添加量有一最佳值；氯化镁及氢氧化钠具有负作用。添加剂通过影响石灰石的热分解性能及其气化残物的表面组成而起作用，对石灰石的结构影响较小。     

负载型非晶态Cu／SiO2催化剂局域结构的研究

采用ＸＰＳ和ＥＸＡＦＳ方法，研究了以ｓｏｌ－ｇｅｌ法制得的超累粉体ＳｉＯ２为载体，用化学还原沉积法制备的负载型非晶态Ｃｕ／ＳｉＯ２催化剂在甲酸甲酯氢解反应前后的表面结构和局域结构。结果表明，非晶态样品中的铜原子以零价铜的形式存在，但配位数却大幅度地低于铜樯档，意味着铜原子在高比表面超细ＳｉＯ２载体上处于高分散的非晶状态，表面悬空键显著增多，表面能增大，导致配位键收缩。     

加氢处理催化剂载体中Y型分子筛组分对催化剂表面性质和催化性能的影响

应用ＸＲＤ，ＸＰＳ，ＩＲ－ＴＰＤ，ＣＯ２和ＮＯ吸附及正庚烷裂解和噻吩加氢脱硫脉冲微反等方法，研究了加氢处理催化剂载体经Ｙ型分子筛改性前后各种性质的变化，结果表明，载体经Ｙ型分子筛改性后，催化剂的Ｂ酸、正庚烷裂解活性和异构选择性明显提高，Ｙ型分子筛以分散的形式分布于γ－Ａｌ２Ｏ３表面，减少了载体表面的空位铝，该催化剂中有盯当一部分金属组分进入Ｙ型分子筛孔道与３其Ｂ酸位作用，与ＮｉＱ／γＡｌ２Ｏ３相比     

氟钽酸钾中碳存在形式的探讨

本文从氟钽酸钾（Ｋ２ＴａＦ６）的生产工艺论述了有机物存在于Ｄ２ＴａＦ６的可能性。通过Ｋ２ＴａＦ６低温通氧燃烧前后测定碳的结果比较，以及Ｘ射线能谱仪表面分析结果，证实了碳的来源是残留的有机萃取剂。     

碱金属氟化物/La2O3催化剂上的甲烷氧化偶联

研究了碱金属氟化物添加剂对Ｌａ２Ｏ３的甲烷氧化偶联反应催化性能的影响，发现ＮａＦ的促进效应最明显，还研究了ＮａＦ含量对催化剂 批表面积、活性选择性的影响，发现催人上比表面积与活性存在着对应关系，温度改变，催化剂的活性选择性了将随之发生变化，在１０７３Ｋ，Ｃ２收率达到最大值，约１８．０％，应用ＸＲＤ，ＸＰＳ等技术对反应前后催化剂的表面组成和结构进行了表征。     

活性碳纤维氧化还原吸附Pd^2＋机理的研究—XPS的研究

在以前２所作ＶＡＣＦ氧化还原吸附Ｐｄ＾２＋的研究基础上，用Ｘ射线光电子能谱（ＸＰＳ）和其他分析方法对ＶＡＣＦ吸附Ｐｄ＾２＋前后的表面化学结构进行了系统分析。结果表明：ＶＡＣＦ表面的还原性基团越多，还原能力越强，越有利于ＶＡＣＦ对Ｐｄ＾２＋的氧化还原吸附。凡明利于Ｐｄ＾２＋电极电位提高的因素，都 有利于ＶＡＣＦ的氧化还原吸附。适当调节吸附液的Ｐ至ＶＡＣＦ的氧化还原吸附同样是有利的。     

Ni-P/SiO2催化剂晶化过程及其加氢活性研究

采用化学还原法制备了负载型Ｎｉ－Ｐ／ＳｉＯ２非晶态合金催化剂,应用ＩＣＰ、ＢＥＴ、氢氧滴定法、ＸＲＤ、ＳＥＭ、ＸＰＳ研究了上述催化剂在高温晶化过程中的表面结构、表面形貌和表面电子态的变化。测定了Ｎｉ－Ｐ／ＳｉＯ２非晶态合金晶化前后对其液相苯甲醛加氢反应催化活性和选择性。并讨论了非晶态合金催化剂晶化过程中结构变化对催化性能的影响。     

Thermal behaviour of teflon/phenolic liners in self-lubricating bearings

The gun system of the M1 series tank rides on a pair of self-aligning spherical bearings that allows the elevation and depression of the cannon. Because these bearings are encapsulated within the rotor housing, periodic lubrication or maintenance is impossible. To overcome this problem self-lubricating bearings were incorporated into the system. There are two basic liner designs, molded and fabric. Molded liners are produced by applying a formulation of teflon and typically asbestos into a phenolic resin, which is applied to the bearing surface, then cured. Fabric liners utilize a woven fabric bonded to the bearing surface, then teflon which is mixed into phenolic resin is applied to the bearing surface and cured. Initial studies of the existing bearing liner were completed to determine the liner composition and establish a baseline or standard to compare thermal and mechanical properties with potential vendors. DSC revealed an average teflon content of 39.53%, which varied significantly throughout the liner. TG analysis showed an asbestos concentration of 12.22%. The remainder of the liner was phenolic resin. Physical testing of the bearing from ?20 to 120?C under normal loading conditions demonstrated excellent thermal stability with little wear. Bearings from each vendor were tested and compared to the standard properties of the baseline bearing. Some properties were difficult to compare or insignificant due to the design differences between molded and fabric liners. The testing program resulted in the qualification of two bearings, which met or exceeded the established standards. Both of these bearings were designed with fabric liners.     

Effect of solid lubricant particles on the tribological properties of PTFE composites lubricated with natural seawater

An orthogonal test was used to design different mixture ratios of molybdenum disulfide(MoS₂), graphite, and SiO₂ particles, which were filled with polytetrafluoroethylene (PTFE) composite. MoS₂-, graphite-, and SiO₂-modified PTFE was obtained by pressing and sintering, and the processing parameters were determined using progressive studies and experiments. The friction and wear properties of different PTFE composites lubricated with natural seawater were analyzed using an MMU-5G wear tester. A laser scanning confocal microscope was employed to examine the morphological characteristics of the worn surface. Moreover, the influence of particle proportions on the tribological property of composites was analyzed. Results show that the addition of SiO₂, MoS₂, and graphite can increase the bearing capacity, improve the wear resistance, reduce the friction coefficient, and increase the self-lubricating ability of the PTFE matrix.     

Surface stress-dependent adhesion to fluorinated polymers

Irradiation of thin commercial sheets of poly(tetrafluoroethylene) (PTFE) or a fluorinated ethylene-propylene copolymer (FEP) yield essentially the same results with mass spectroscopy or x-ray photoelectron spectroscopy (XPS). For both gas phase and surface (ca. 30 Å) products of irradiation, the same product distributions and exposure dependencies are observed. In addition, XPS of chemically etched (with sodium naphthalenide) PTFE and FEP shows the same extent of surface defluorination. In contrast to the more surface-sensitive XPS, Rutherford backscattering spectroscopy of etched PTFE shows that the defluorination extends to depths of ca. 3000 Å, while with etched FEP defluorination extends to only a few hundred Angstroms. Scanning electron microscopy shows the FEP surface to be smooth and featureless both before and after chemical etching, while etched PTFE is characterized by a crazed surface with a high density of unidirectional cracks oriented perpendicular to long macroscopic scratches existing in the virgin surface. Adhesion of Cu to this etched PTFE has previously been shown to be sufficiently strong that failure is a result of near-cohesive failure in the PTFE and not adhesive failure. Conversely, weak adhesion of Cu to etched FEP or to other smooth forms of fluorinated polymers, including polished PTFE, is observed. This correlation of strong adhesion with surface roughness and not with surface chemical changes is consistent with previous suggestions that a major component of adhesion to fluorinated polymers is mechanical interlocking. The differences between FEP and PTFE are discussed in terms of a model involving surface stresses expected from their different methods of manufacture: extrusion from the melt in the case of FEP and skiving from pressed cylinders in the case of PTFE. © 1994 John Wiley & Sons, Inc.     

Improvement of adhesive bonding of thermoplastic polymers by different surface treatments

Injection moulded samples of six species of thermoplastic polymers were exposed to different surface treatments and successively glued together to form single lap shear joints. Lap shear strength and failure mode of these specimens were examined. The surfaces obtained after treatment were characterized by electron spectroscopy for chemical analysis, contact angle measurements and atomic force microscopy.     

连续纤维增强含二氮杂萘酮联苯结构聚芳醚砜酮树脂基复合材料的界面

利用射频感性耦合冷等离子体(ICP)处理技术改性连续纤维表面,分别采用X射线光电子能谱(XPS)、原子力显微镜(AFM)及动态接触角分析(DCA)系统研究了等离子体处理时间、放电气压、放电功率等工艺参数对连续碳纤维、芳纶纤维和对亚苯基苯并二噁唑(PBO)纤维的表面化学成分、表面形貌、表面粗糙度及表面自由能的影响.研究结...     

Threshold Al KLL Auger spectra of oxidized aluminium foils

Threshold Al KLL Auger electron spectroscopy and K‐edge x‐ray absorption fine structure spectroscopy have been used to examine technical purity (99.5%) aluminium foil before and after chemical treatment that altered the thickness and degree of hydroxylation of the oxidized layer. Comprehensive surface chemical characterization was effected by means of monochromatized Al Kα‐excited photoelectron spectroscopy. Threshold Al KL_{2, 3}L_{2, 3} spectra were obtained for three of the foils investigated and these spectra were in broad agreement with those observed previously for pure Al foil. The relative intensities of the spectral components for two of the foils were clearly consistent with the previously proposed assignment of the resonantly enhanced Auger component, situated between those arising from the metal and Al(III) oxide, to a thin interfacial layer. The threshold Auger spectra from the aluminium foil bearing the thickest and most hydroxylated oxidized layer were not obviously consistent with the interfacial layer model but O K‐edge spectra revealed that this surface layer was fundamentally different from the others and could have had a greater interfacial surface area. Copyright © 2003 John Wiley & Sons, Ltd.     

Nonwetting process for achieving surface functionalization of chemically stable poly(tetrafluoroethylene)

Using a low-energy Ar+ ion-beam with and without a reactive gas, chemically stable poly(tetrafluoroethylene) (PTFE) films were modified to have special surface features. The adhesion strength between the PTFE and the copper was significantly improved because of both changes in the surface topography and chemical interactions due to PTFE functionalization (oxidation and amination). The surface modification altered the failure mode from adhesive failure for the unmodified PTFE/Cu interface to cohesive failure for the surface-modified PTFE/Cu layer interface.     

Sintered silica colloidal crystals with fully hydroxylated surfaces

Silica colloidal crystals require multiple processing steps before they are useful materials in analytical applications, such as chemical separations, microarrays, sensors, and total internal reflection microscopy. These chemical processing steps include calcination, sintering, surface rehydroxylation, and chemical modification, but these steps have not been fully characterized for colloidal crystals. Silica particles of nominally 200 nm in diameter were prepared, and FTIR, SEM, UV-visible spectroscopy, and refractive index measurements were used to study the changes in chemical composition, particle size, and particle density throughout the process. The final material is shown to be a durable, crack-free crystal of solid particles bearing a fully hydroxylated surface of silanols, which can then be chemically modified.     

Two-Dimensional (2D) Porous Zinc Oxides Derived from the Coordination Polymer via Chemical-Assisted Phase Transition

Two-dimensional (2D) porous zinc oxides (ZnO) were successfully prepared via chemical treatment and thermal annealing of coordination polymers (CPs) precursors consisting of Zn(II) ion and fumarate ligand. The morphology, crystalline phase, chemical state, and surface area of the resultant ZnO were characterized. It is experimentally discovered that the crystal phase of the CP bearing Zn(II) ions is transformed to the zinc hydroxide crystal phase by chemical treatment using ammonia water. The prepared CP-derived porous 2D ZnO exhibited enhanced photocatalytic efficiency for dye degradation under black-light irradiation (365 nm) compared to CP-derived non-porous ZnO without a chemical-assisted phase transition process.     

Analysis of fatigue behaviour of notched specimens made of fibreglass reinforced polyamide by means of a cohesive model

Fatigue tests until fracture of five notched specimens of short glass fibre reinforced polyamide, with a humidity of 2.5%, were carried out at 23, 28, 33, 38 and 43 °C. A correlation between the environmental temperature and the number of cycles to failure was established. Three different regions of strain were observed, namely, transient, steady-state and pre-failure. Strain and strain-rate during the creep-fatigue process revealed the existence of non-temperature dependent critical strains between these regions. The fractographic study performed after failure suggested the suitability of describing the stress distribution in the remnant ligament through a cohesive model. This is based on the observed fact that, at the crack tip, the matrix and the fibres debond, giving rise to crazing mechanisms so that the ultimate bearing ability of the material relies on the matrix. The calculations involved in the cohesive model were based on the information provided by the fractographic study and the real-time measurements of the crack growth by means of an infrared thermographic camera. Based on this methodology, the cohesive stress of the material was estimated. In a last stage, the surface roughness of the samples was determined after being tested, revealing a reliable correlation between the roughness and the fracture micromechanisms undergone by the underlying material. This correlation makes it possible to use the surface roughness of an in-service component as a parameter to evaluate the level of microstructural damage that it has experienced.