不同工艺制备的高反射薄膜在真空与大气环境下的激光损伤特性

建立了光学元件在真空环境下的激光损伤测量系统,采用电子束蒸发和离子辅助技术制备了Hf2/SiO2高反射薄膜。对不同工艺制备的薄膜在真空与大气环境下的1 064 nm波长的激光损伤阈值进行了测量,对薄膜的损伤形貌进行了观测。对薄膜的损伤特性研究分析结果表明：薄膜在真空环境中的损伤阈值相对大气环境中有明显下降,其1∶1测试和R1测试损伤阈值下降约30%;两种环境中的薄膜损伤特性也不同,真空环境中损伤阈值的下降可能与热传导的不同有关。     

实时测量308 nm 激光对薄膜的损伤阈值

用散射光法, 建立了一套实时监视与测量308nm 激光对全反膜和增透膜的损伤的实验装置。实时观察到了损伤从起始、加深直至饱和的整个过程的波形。用这一装置测量了全反膜和增透膜在308nm 激光作用下的损伤阈值。测得全反膜在0°与45°入射角时的损伤阈值分别为1.7与1.0J/cm2。而增透膜的阈值为1.3J/cm2。     

激光输出特性对介质薄膜损伤的影响

采用输出特性不同的几种激光器测量了多种介质光学薄膜的破坏阈值,并对典型的破坏过程进行显微分析。研究了激光输出特性的不同对薄膜损伤效果的影响:在相同能量输出的条件下,脉冲激光比连续激光更容易形成有效的破坏;连续激光则能通过能量积累而更容易对作用目标造成烧蚀破坏。     

Anticorrosive and Microbial Inhibition Performance of a Coating Loaded with Andrographis paniculata on Stainless Steel in Seawater

With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.     

Novel marine antifouling coatings inspired by corals

Biofouling is a major problem facing the marine industry. Since toxic antifouling coatings were banned globally due to their negative impacts on the marine environment, the development of environmental-friendly and efficient antifouling coatings has been identified as a pressing need. As an alternative, the antifouling coatings inspired by corals have attracted a great deal of attention over these years. within the marine environment, corals have evolved an excellent antifouling capability. There are five major antifouling strategies applied by corals, including natural antifoulants, foul release effect, sloughing effect, soft tentacles, and fluorescence effect. In this paper, a brief review is conducted to introduce the antifouling coatings inspired by the five strategies. Moreover, a discussion is conducted about the existing problems with the five strategies and the direction of their further development is indicated.     

溶液等离子喷涂氧化锆涂层力学性能的研究

采用溶液等离子喷涂技术(SPPS)制备了氧化钇部分稳定氧化锆(7YSZ)热障涂层(TBCs).热障涂层剥落失效的影响因素众多,其中很多都与涂层的力学性能相关.利用扫描电镜(SEM)、X射线衍射仪(XRD)和硬度计等研究了涂层的力学性能.结果表明,SPPS涂层的弹性模量约为58 GPa,硬度约为7 GPa,比大气等离子喷涂(APS)涂层高了15;左右;SPPS涂层的断裂韧性为1.8~2 MPa·m1/2,结合强度约为25 MPa.SPPS涂层因为低的孔隙率和更好的板条之间的结合带来了力学性能的提升.     

A study of polyesters synthesized from an arylsilane and its carbon analog

Bis(4,4′-benzoyl chloride) dimethylsilane (SiCO) and 2,2-bis(4,4′-benzoyl chloride) propane (CCO) were synthesized and polymerized with butanediol, resorcinol, or hydroquinone. The polymers of SiCO–hydroquinone (SiCO–Hyd) and SiCO–resorcinol (SiCO–Res) possess glass transition temperatures 25°C lower than their carbon analogs but the less aromatic SiCO–butanediol (SiCO–BDO) and CCO–butanediol (CCO–BDO) polymers have similar glass transitions. Silicon containing polymers are superior to their carbon counterparts in thermal stability. Furthermore, polyarylates of excellent thermal stability and solubility were synthesized from SiCO/terephthaloyl chloride and hydroquinone. © 1993 John Wiley & Sons, Inc.     

Acoustic emission evaluation of the fracture behavior of APS‐TBCs subjecting to bondcoating oxidation

Air‐plasma‐sprayed (APS) thermal barrier coatings (TBCs) under the conditions of without TBC, as‐sprayed and preoxidized, were tested under tensile loading, and their acoustic emission (AE) responses were monitored. AE parameters including event count, amplitude, and frequency spectrum realized by Fast Fourier Transformation (FFT) were analyzed for information regarding the fracture behavior of TBCs. On the basis of AE behavior, the fracture process of TBCs and corresponding cracking patterns in TBCs subjected to tensile tests were evaluated. AE results also showed that the bondcoating oxidation not only promotes the cracking but also changes the failure mode in TBCs. Copyright © 2007 John Wiley & Sons, Ltd.     

Open tubular CEC with novel block copolymer coatings for separation of aromatic amines

A new type of block copolymer, which was synthesized by styrene and maleic anhydride, P(MAn‐alt‐St)₁₁₉‐b‐PSt₅₅₈, was successfully developed as the capillary coatings in open tubular CEC. It is interesting that the covalently bonded coatings are porous and the coatings can play the role of surfactants in the separation of aromatic amines when the buffer solution was composed of 30.0 mM ammonium acetate at pH 7.7 with 20% THF. Thus, successful baseline separation of five kinds of aromatic amines has been achieved. As validated by both artificially prepared solutions of aromatic amines and four real samples of commercially available permanent hair dyes, this proposed method was successfully applicable to the quantitative analysis of p‐phenylenediamine (PPD) and o‐phenylenediamine (OPD) ingredients in these commercial products, with a linear range between 8.3 μM and 6.0 mM, correlation coefficient above 0.990 and recovery between 83.5 and 110.9%. The detection limit obtained from calculations based on signal‐to‐noise ratio (S/N=3) was 4.2 μM for PPD and 6.0 μM for OPD, respectively. Furthermore, the role of the surfactants played by the block copolymer coatings has been primarily explored.     

Superconducting coatings of MgB2 prepared by electrophoretic deposition

The electrophoretic deposition technique was applied for the production of MgB₂ superconducting coatings on various substrates, by using a suspension of MgB₂ superconducting powder in an organic solvent. The main parameters that affect the deposition rate of the process and the quality of the coatings produced, such as the initial concentration of the suspension, the applied voltage and the distance between the electrodes, were investigated and optimized. The coatings produced were characterized and investigated for possible interaction between the substrate and the deposited superconductor by X-ray diffraction. The superconducting properties were measured by magnetic susceptibility (superconducting quantum interference device).