螺旋线镀金薄膜磁控溅射设备的研制

本文详细介绍了用于螺旋线镀金薄膜的磁控溅射设备的研制过程。首先明确了该设备的研制难点,其次对设备的主要组成部分进行了详细的说明,针对设备的几个研制难点提出了解决方案,最后利用研制好的设备进行了膜厚均匀性分析实验。实验表明膜层均匀性良好,达到了预期要求,客户反馈良好。     

Selective molecularly imprinted polymer nanofiber sorbent for the extraction of bisphenol A in a water sample

Novel molecularly imprinted polymer nanofibers (MIP‐NFs) were prepared for the adsorption of bisphenol A (BPA) in a water sample using the sol–gel process and the electrospinning technique. The effects of a number of synthesis parameters on the adsorption efficiency were investigated. The successful removal of BPA from MIP‐NFs was studied using UV–visible spectroscopy. The prepared MIP‐NFs were characterized by Fourier transform infrared, field emission SEM, TEM and energy dispersive X‐ray analysis. The results showed that the required molar ratio of 3‐aminopropyltriethoxysilane (APTES) to BPA was 15:1, which indicates a good performance in the rebinding test. Likewise, the molar ratio of APTES:acid:water was 1:2:9. The nylon 6 polymer solution, with a concentration of 12 wt%, showed a maximum adsorption capacity for BPA due to a decrease in the nanofiber diameter and an increase in the accessible sites. Furthermore, the maximum adsorption capacity of BPA was achieved at pH 7. Concerning the binding of BPA on MIP‐NFs, the experimental data matched well with the pseudo‐second‐order kinetics data and the Sips isotherm model. The saturated binding capacity for MIP‐NFs was predicted to be 115.1 mg g^?1, which was more than twice as high as that for non‐imprinted polymer nanofibers (46.82 mg g^?1). The results obtained in this study confirmed that the prepared MIP‐NFs showed considerable binding specificity for BPA in comparison with similar structural compounds such as phenol, naphthol and Naphthol AS, in aqueous solution. The binding capacity of MIP‐NFs remained almost constant after five cycles of reuse. The real sample analysis indicated that MIP‐NFs could be utilized as a useful sorbent material for the extraction of BPA from a water sample.     

激励对往复式骨架油封密封性能的影响

为改善往复式骨架油封的泄漏问题,建立油封唇口密封区流体润滑的数值计算模型,模型考虑密封面粗糙形貌以及油封唇口的径向变形,通过求解雷诺方程分析密封区的流体力学特性,获得密封区的油膜厚度和压力分布,并分析激振频率和振幅对密封性能的影响规律。结果表明:随着激振频率的增加,内外行程中密封区的最小膜厚呈先增加后减小的变化趋势,激振频率越大,往复式骨架油封的密封性越差;内外行程中密封区的的最小膜厚随激振振幅的增加呈非线性增加,激振振幅越大,往复式骨架油封的密封性越好。综合考虑,为提高密封效果,往复式骨架油封适用于小频高幅的工作场合。     

表面形貌对粗糙接触界面流体润滑特性的影响

为探究不同表面形貌对粗糙接触界面液体润滑特性的影响，基于有限差分法结合雷诺方程和膜厚方程，研究阶梯形貌、波纹形貌、随机形貌和峡谷形貌4种不同粗糙接触界面液体润滑时的载荷分布及规律。研究发现：4种粗糙表面的三维载荷分布规律都与其表面形貌相对应，在波“峰”处载荷大，摩擦力随载荷的增大而增大，在波“谷”载荷小，摩擦力随载荷减小而减小；4种粗糙表面的载荷随表面展开面积比的变化趋势却有所不同；随表面展开面积比的增大，阶梯形貌表面的载荷呈线性增大，波纹形貌表面的载荷基本不变，随机分布形貌表面的载荷呈增大趋势，峡谷形貌表面的载荷呈先增大后减小的变化趋势。研究结果可以进一步补充现有表面形貌表征和流体润滑等相关研究理论。     

A state-of-the-art review on the elaboration of fish gelatin as bioactive packaging: Special emphasis on nanotechnology-based approaches

BackgroundThe last decade has noticed the expansion of green materials, which aims to reduce the human impact on the environment. Green polymers are clearly tendency subdivision of this stream and numerous bio-sourced plastics have been developed. Recent research has further focused on the development of new bio-based materials such as edible/biodegradable films for food products.Scope and approachFish gelatin (FG), a protein with recreatable reserve, biodegradability, and processability, has a remarkable potential in bio-packaging. However, there have been noticeable issues concerning the use of FG as packing material, including its low mechanical strength, poor moisture stability, and poor water barrier properties. This paper aims to review the state-of-the-art in development of FG-based films and highlights how they play a crucial role in modifying the properties of such films. Various types of nanofillers that have been included into FG to fabricate bio-nanocomposite films, such as nanoclays (montmorillonite, sepiolite), polysaccharide nanofillers (nanowhiskers/nanofibers), metal ions (silver, copper) and metal oxides nanoparticles (ZnO, TiO₂) are reviewed.Key findings and conclusionsCross-linking is a promising technique to improve the performance and applicability of FG-based biomaterials, particularly respecting their water sensitivity, which hinders many of their potential uses as food contact materials. Bio-nanocomposite technology may help to make high-performance materials with extra bio-functional properties, and it is anticipated to be a dynamic research in the future. In general, more research is required to ameliorate application processes of FG films, especially physical aspects, to be suitable for bio-packaging application.     

Flexible and Conductive 3D Printable Polyvinylidene Fluoride and Poly(N,N‐dimethylacrylamide) Based Gel Polymer Electrolytes

In this work, 3D printable gel polymer electrolytes (GPEs) based on N,N‐dimethylacrylamide (DMAAm) and polyvinylidene fluoride (PVDF) in lithium chloride containing ethylene glycol solution are synthesized and their physicochemical properties are investigated. 3D printing is carried out with a customized stereolithography type 3D gel printer named “Soft and Wet Intelligent Matter‐Easy Realizer” and free forming GPE samples having variable shapes and sizes are obtained. Printed PVDF/PDMAAm‐based GPEs exhibit tunable mechanical properties and favorable thermal stability. Electrochemical proprieties of the printed GPEs are carried out via impedance spectroscopy in the temperature range of 25–90 °C by varying PVDF content. Ionic conductivity as high as 6.5 × 10^?4 S cm^?1 is achieved at room temperature for GPE containing low PVDF content (5 wt%) and conductivity of the GPEs is increased as temperature rises.     

改性防护蜡对轮胎胎侧胶性能的影响

研究改性防护蜡对轮胎胎侧胶性能的影响。结果表明,与传统防护蜡相比,改性防护蜡异构烷烃质量分数较小,结晶尺寸小且致密程度高。改性防护蜡可在不影响胎侧胶硫化特性和物理性能的前提下,大幅提高胎侧胶抗喷霜性能,保证轮胎表面不受臭氧侵蚀,在防止裂纹产生的同时明显改善成品轮胎外观。     

Agreement and repeatability of four different devices to measure non-invasive tear breakup time (NIBUT)

PurposeSince tear film stability can be affected by fluorescein, the Dry Eye Workshop (DEWSII) recommended non-invasive measurement of tear breakup time (NIBUT). The aim of this study was to investigate the agreement and repeatability of four different instruments in the measurement of NIBUT.Methods72 participants (mean 24.2 ± 3.6 years) were recruited for this multi-centre, cross-sectional study. NIBUT was measured three times from one eye using each of the instruments in randomized order on two separate sessions during a day, separated by at least 2 h. NIBUT was performed at three sites (Switzerland, Germany and UK) using three subjective instruments, Tearscope Plus (Keeler, Windsor, UK) (TS), Polaris (bon Optic, Lübeck, Germany) (POL), EasyTear Viewplus (Easytear, Rovereto, Italy) (ET) and the objective Keratograph 5 M (Oculus Optikgeräte GmbH, Wetzlar, Germany) (KER). As the latter instrument only analyses for 24 s, all data was capped at this value.ResultsNIBUT measurements (average of both sessions) between the four instruments were not statistically significantly different: TS (median 10.4, range 2.0–24.0 s), POL (10.1, 1.0–24.0 s), ET (10.6, 1.0–24.0 s) and KER (11.1, 2.6–24.0 s) (p = 0.949). The objective KER measures were on average (1.2 s ± 9.6 s, 95 % confidence interval) greater than the subjective evaluations of NIBUT with the other instruments (mean difference 0.4 s ± 7.7 s, 95 % confidence interval), resulting in a higher limits of agreement. The slope was -0.08 to 0.11 indicating no bias in the difference between instruments with the magnitude of the NIBUT. Repeated measurements from the two sessions were not significantly different for TS (p = 0.584), POL (p = 0.549), ET (p = 0.701) or KER (p = 0.261).ConclusionsThe four instruments evaluated for their measurement of tear stability were reasonably repeatable and give similar average results.     

固溶处理对2205双相不锈钢组织及钝化膜特性的影响

用不同温度对2205双相不锈钢进行固溶处理,利用定量金相法及硬度法、电化学极化试验、电化学阻抗谱试验的方法研究固溶温度与2205双相不锈钢微观组织和钝化膜特性之间的关系。结果表明,当固溶温度为950 ℃时,有σ相存在,分布于铁素体/奥氏体晶界,当固溶温度为1000 ℃时,σ相消失,铁素体相比例随固溶温度的升高而升高,奥氏体相比例则呈相反规律;电化学试验和阻抗谱试验结果显示,材料在950 ℃时钝化膜稳定性和耐蚀性能最差,在1050 ℃时钝化膜稳定性和耐蚀性能最好。     

基于优化遗传算法改进的小波网络预测锰系磷化膜的耐蚀性

针对小波网络训练速率较慢、结构不易确定等问题,结合实验选取的因素(包括输入参数和输出结果),通过仿真确定了小波网络的结构为3-7-1。接着,利用优化遗传算法对小波网络进行改进,修正其初始权值和因子。通过仿真证实了改进的小波网络具备更强的寻优能力和更快的收敛速率。最后,利用改进的小波网络预测锰系磷化膜的耐蚀性。结果表明:改进的小波网络可以更好地拟合样本数据,能够进行较准确的预测。