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81.
In this article, macromolecular charring agent linear novolac (NA) was served as a synergist with nitrogen‐phosphorous flame retardant melamine polyphosphate (MPP) for the flame‐resistance of wollastonite (WT) filled polyamide 66 (PA66). The investigations showed that MPP/NA system possessed obvious synergistic effects by increasing the charring rate and amount, therefore, showing much higher flame retardancy than the filled PA66 flame retarded with MPP alone. The corresponding char layer structure of MPP/WT/PA66 and MPP/NA/WT/PA66 was investigated and their difference was analyzed. In addition, as a multifunctional additive, NA could act as a compatibilizer and lubricant in the system, and endowed the material with improved mechanical performance and processability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
82.
The elastomer toughening of PA66/PA6 nanocomposites prepared from the organic modified montmorillonite (OMMT) was examined as a means of balancing stiffness/strength versus toughness/ductility. Several different formulations varying in OMMT content were made by mixing of PA6 and OMMT as a master‐batch and then blending it with PA66 and different elastomers in a twin screw extruder. In this sequence, the OMMT layers were well exfoliated in the nylon alloy matrix. The introduction of silicate layers with PA6 induced the appearance of the γ crystal phase in the nanocomposites, which is unstable and seldom appears in PA66 at room temperature and it further affected the morphology and dispersion of rubber phase resulting in much smaller rubber particles. The incorporation of POE‐g‐MA particles toughened the nanocomposites markedly, but the tensile modulus and strength were both reduced. Conversely, the use of OMMT increased the modulus but decreased the fracture toughness. The nanocomposites exhibited balanced stiffness and toughness. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
83.
Bowen Du Yuhong Luo Feichao Wu Guihua Liu Jingde Li Wei Xue 《Frontiers of Chemical Science and Engineering》2023,17(2):194
The shuttle effect of soluble polysulfides is a serious problem impeding the development of lithium−sulfur batteries. Herein, continuous amino-functionalized University of Oslo 66 membranes supported on carbon nanotube films are proposed as ion-permselective interlayers that overcome these issues and show outstanding suppression of the polysulfide shuttle effect. The proposed membrane material has appropriately sized pores, and can act as ionic sieves and serve as barriers to polysulfides transport while allowing the passage of lithium ions during electrochemical cycles, thereby validly preventing the shuttling of polysulfides. Moreover, a fast catalytic conversion of polysulfides is also achieved with the as-developed interlayer. Therefore, lithium−sulfur batteries with this interlayer show a desirable initial capacity of 999.21 mAh·g–1 at 1 C and a durable cyclic stability with a decay rate of only 0.04% per cycle over 300 cycles. Moreover, a high area capacity of 4.82 mAh·cm–2 is also obtained even under increased sulfur loading (5.12 mg·cm–2) and a lean-electrolyte condition (E/S = 4.8 μL·mg–1). 相似文献
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在传动系统中,尼龙66制零件会与碳钢零件配合传递运动和转矩,由于尼龙66硬度远远低于碳钢,所以尼龙66制零件表面极易产生磨损导致失效,因此在产品设计中必须考虑尼龙66的摩擦磨损。为有效评估尼龙66与碳钢配对运行的摩擦磨损性能,在不同载荷下进行尼龙66/45钢摩擦副的摩擦磨损试验,通过超景深显微镜观察磨损形貌及磨痕的深度,采用灰色系统理论建立磨损量预测的灰色GM(1,1)模型,建立考虑表面接触应力的磨损量预测模型。结果表明:采用灰色理论预测尼龙66/45钢的磨损量具有高精度和高可靠性,预测值和试验值的最大误差为9.26%,平均相对误差为3.60%。采用该预测模型进行尼龙零部件磨损寿命设计,无需开展大量重复性的磨损试验,能够快速为尼龙零部件的产品设计提供磨损量的参数指标。 相似文献
86.
Timpano Kiara R.; Schmidt Norman B.; Wheaton Michael G.; Wendland Jens R.; Murphy Dennis L. 《Canadian Metallurgical Quarterly》2011,120(3):700
The gene coding for the brain derived neurotrophic factor (BDNF) has emerged as an interesting candidate for multiple brain and brain disorder-related phenomena. The primary aim of the present investigation was to consider the relationship between the BDNF Val66Met variant and two phenotypes: compulsive hoarding as a symptom dimension of obsessive–compulsive disorder (OCD), and body mass index (BMI). We examined the BDNF gene in a large (N = 301) clinical sample of probands with OCD. Participants were classified as hoarding or nonhoarding using a strict, multimeasure grouping approach. Results revealed that the Val/Val genotype was linked with hoarding classification and more severe hoarding behaviors, as well as greater BMI levels. Hoarding status was also associated with greater BMI scores, with individuals in the hoarding group being far more likely to be classified as obese compared with the nonhoarding group. Our findings may provide a distinct avenue through which hoarding and BMI could be linked. These findings are suggestive of a complex gene, body weight, and psychopathology relationship wherein a primitive, survival “thrifty gene” strategy may be conserved and represented in a subgroup of humans manifesting severe hoarding symptoms. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
87.
方法 根据杜66块蒸汽驱油藏的地质构造和射孔生产井段,设计了耐高温高压热电偶束及地面直读仪表,在井下同时监测各油层的温度变化。目的 解决蒸汽驱采油工艺的油藏动态监测问题。结果 该项技术经地面试验检测后,在观6井进行了现场应用,其监测结果与根据井筒模型和生产参数计算的结果相符。结论 蒸汽驱油藏温度剖面监测技术解决了蒸汽驱开采过程中油藏动态的监测问题,热电偶束技术可实现各油层同时连续监测,与地面系统配 相似文献
88.
89.
Cu_(66)Ti_(34)非晶合金凝固过程的分子动力学模拟 总被引:1,自引:0,他引:1
采用分子动力学模拟了二元合金Cu66Ti34的凝固过程。原子间作用采用GEAM势,利用偶关联函数,均方位移(MSD)等分析方法,研究Cu66Ti34合金在4×1013 K/s冷却速度下的玻璃化转变温度、原子的扩散行为。结果表明,通过偶分布函数第一谷的最小值与第一峰最大值之比获得的玻璃转变温度为600 K,与相近成分Cu50Ti50的实验值接近;在800 K时,Cu和Ti的MSD最大值均小于1×10?2 nm2,合金熔体很粘稠;在600 K时,曲线的斜率降低,在动力学上合金熔体已经凝固。定压比热容与温度成二次分布关系,存在一个峰值温度为892 K的热力学玻璃转变温度,证明了用动力学方法和用热力学方法获得的玻璃转变温度之间的差异。 相似文献
90.