纳米碳纤维/碳毡负载碳化钨和碳氮化钨的肼分解性能

以纳米碳纤维/碳毡(CFF)为载体,分别采用碳热氢气还原法和碳热氨气还原法制备了负载型碳化钨、碳氮化钨整体催化剂,XRD结果表明催化剂的活性相分别为W₂C和WC_xN_y, TEM表征发现其粒子尺寸分别为2～40 nm和2～20 nm。采用1 N肼分解推力器评价了上述催化剂的反应性能,W₂C/CFF和WC_xN_y/CFF表现出了相比于Ir/CFF更好的肼分解综合性能:除了初活性略低以外,启动加速性、稳态燃压以及比活性均高于贵金属Ir催化剂。此外,W₂C/CFF和WC_xN_y/CFF催化剂的稳定性明显优于Ir/CFF,这主要是由于CFF载体在贵金属Ir的作用下发生了更显著的甲烷化反应。     

发散法接枝聚酰胺-胺改性碳纤维织物及其应用研究

采用发散法,以乙二胺(EDA)为引发核,与丙烯酸甲酯(MA)通过迈克尔加成和酰胺化反应将1.0代聚酰胺-胺(1.0 G PMMAM)接枝到碳纤维织物(CFF)表面,同时将1.0 G PMMAM作为双酚A型环氧树脂(EP)的固化剂,制备了接枝改性CFF/EP复合材料,分析了改性CFF的表面结构及改性前后CFF/EP复合材料的力学性能。结果表明:通过迈克尔加成和酰胺化反应,1.0 G PAMAM被成功地接枝在CFF表面;接枝改性后CFF表面粗糙度增加,沟壑变得更密,且其类石墨的有序结构遭到破坏,无序性增加;接枝改性CFF/EP复合材料的弯曲强度、剪切强度和冲击强度较未改性CFF/EP复合材料分别提高了102%,99%和30%。     

pCBT/MWNTs/CFF复合材料的制备及力学性能研究

以环状对苯二甲酸丁二醇酯(CBT)为原料,采用双螺杆挤出机反应挤出与热压复合法制备了碳纳米管/聚环状对苯二甲酸丁二醇酯/碳纤维织物(MWNTs/pCBT/CFF)复合材料,研究了酸化处理前后MWNTs的加入对CBT开环聚合的影响,以及MWNTs对pCBT基体及pCBT/CFF复合材料力学性能的影响。结果表明:MWNTs的加入降低了CBT的聚合速率,增大了pCBT树脂的低黏度加工窗口;酸化处理后的MWNTs对pCBT基体具有更加明显的增强增韧效果,并有助于改善pCBT基体与CFF的界面结合力,显著提高了pCBT/CFF复合材料的力学性能;加入酸化处理后的MWNTs质量分数1%,得到的MWNTs/pCBT/CFF复合材料的层间剪切强度和弯曲强度分别较pCBT/CFF复合材料提高了17.7%和32.7%。     

钛酸铝材料综述

钛酸铝材料是集低膨胀和高熔点于一体,但强度低且在一定的温度范围内易分解.着重介绍了钛酸铝材料的结构、性能、合成工艺.在此基础上介绍了目前材料工作者对钛酸铝改性方面的研究以及国内外的研究成果,提出了钛酸铝陶瓷产业化的发展趋势.     

高分子铝盐絮凝剂的应用

目前,聚合氯化铝作为生活用水、工业用水和工业废水等水处理剂已得到广泛应用。为了提高其絮凝性能,研究者做了大量工作,主要是在聚合氯化铝中引入其它离子而形成复合型取型聚合铁铝。作者就高分子铝盐、无机高分子复合铝盐和无机高分子铝盐一有机高分子絮凝剂联用在处理生活用水、工业用水和工业废水等方面做了综述,并提出了聚合铝盐在今后水处理方面的发展趋势。     

高白填料氢铝板材与钙粉板材的性能对比及评价

本文通过试验研究了高白填料氢铝、钙粉及高白填料氢铝与钙粉混合料所制作的人造石板材性能的差异。结果表明,添加了四种不同填料（高白填料氢铝（1^#AH、2^#AH）、钙粉、高白填料氢铝与钙粉混合料（6：4））所制作的人造石板材在以下性能方面存在明显差异：①2^#AH人造石专用料与树脂的混合粘度最低（15900eP）,钙粉与树脂混合粘度最高（18500eP）;②用钙粉作填料制作的人造石板材透光性很低,在钙粉中加入高白填料氢铝后可使人造石板材的透光性明显提高,但是钙粉板的白度较高（L值=82．76）;③在弯曲性能上,高白填料氢铝板材明显优于钙粉板;④在阻燃性能方面,高白填料氢铝（1^#AH、2^#AH）制作的人造石板材的氧指数分别达到43和42．5,钙粉板的氧指数仅为25,加钙粉量为40％的钙粉与高白填料氢铝的混合料制作的人造石板材的氧指数为31。而在拉伸性能、硬度、冲击性能方面相差不大;在耐污性能有所不同,钙粉板对口红的耐污性较好,氢铝、氢铝与钙粉混合料制作的人造石板材对醋和酱油的耐污性比较好。     

钛酸铝陶瓷及其研究新进展

为了总结近年来国内外对钛酸铝陶瓷的最新研究进展,推动钛酸铝的研究,本文综述了钛酸铝陶瓷的易分解和低强度机理,着重介绍了采用添加剂法、复合相法以及新的合成、成形、烧结等工艺改善钛酸铝陶瓷性能方面的研究进展,并对其最新的应用研究进展作出简单的介绍,更在此基础上提出了钛酸铝陶瓷的发展动向。     

钛酸铝陶瓷及其研究现状

本文简述了钛酸铝陶瓷的制备及性能,论述了钛酸铝陶瓷的稳定性、微裂纹、低热膨胀性,讨论了工艺条件及外加剂对钛酸铝材料性能的影响,最后提出了改善钛酸铝陶瓷性能的技术途径。     

含铁沸石分子筛中硅铝比的测定

针对含铁沸石分子筛,提出用硅钼蓝光度法测硅,用EDTA和硝酸铅滴定法测铝铁合量,再用磺基水杨酸光度法测铁,根据测试结果计算硅、铝、铁的含量及求出硅铝物质的量比,并通过实验证明该方法简单可行。通过硅铝物质的量比的测定,能为分子筛产品的性能提供重要参考指标和理论依据,而且,根据实际需要,还可调整沸石的硅铝物质的量比,来满足所需性能。另外,本方法因为所需化学药剂常见,在一般实验室均可进行,所以在经济上和适用范围上都有较明显的优势,参考价值显著。     

水泥窑烧成带用镁铁铝尖晶石砖的研制

为了满足水泥窑烧成带用砖无铬化的要求, 以粒度3.5～1mm、<1mm、<0.088mm的高铁镁 砂和粒度<2mm的铁铝尖晶石为原料,分别讨论了 1500℃、1550℃、1600℃、1650℃的烧成温度和 5%、7%、9%、11%的铁铝尖晶石加入量对镁铁铝尖 晶石砖性能的影响。结果表明:当烧成温度为1600 ℃时,试样已烧结;当铁铝尖晶石加入量为7%时,试 样的耐压强度与粘结强度最高(用粘结强度表征材 料的挂窑皮性)。与直接结合镁铬砖相比,镁铁铝尖 晶石砖在热震稳定性方面更优于直接结合镁铬砖,而 在粘挂窑皮性能方面与其相近。     

Effects of sodium hydroxide treatment on the properties of low‐density polyethylene composites filled with chicken feather fiber

The effects of alkali treatment with sodium hydroxide on the tensile properties, morphology, thermal degradation, and mass swell of low‐density polyethylene (LDPE)/(chicken feather fibers (CFF)) composites were studied. The LDPE/CFF composites were prepared by using a Z‐Blade mixer at 180^oC and a rotor speed of 50 rpm. The LDPE/CFF‐_Treated composites exhibited higher tensile strength, Young's modulus, and final decomposition temperature but had lower mass swell percentage and elongation at break than the LDPE/CFF composites. An SEM morphology study showed that the CFF treatment could significantly improve adhesion at the interface and lead to ingress of the fiber into the LDPE phase. Thermogravimetric analysis indicated that the LDPE/CFF‐_Treated composites had higher thermal stability than the LDPE/CFF composites. J. VINYL ADDIT. TECHNOL., 20:36–41, 2014. © 2014 Society of Plastics Engineers     

Parametric study of droplet size in an axisymmetric flow-focusing capillary device

A conventional technique for microfluidic droplet generation is Co-axial Flow Focusing(CFF) in which a contraction zone is placed downstream of the dispersed phase nozzle. In this contraction zone, the dispersed-phase(dphase) fluid is pinched off by continuous-phase(c-phase) fluid to generate micro-droplets. Studying the influence of multiple parameters such as the fluids velocities and viscosities, the interfacial tension, and nozzle and orifice diameters on the droplet size is of great importance for the design and application of CFF devices. Thus,development of more complete numerical models is required. In this paper, we show our model is compatible with experimental data and then numerically investigate the effects of aforementioned parameters on the droplet generation in a CFF microfluidic device. Simulation results showed that the c–phase flow rate, viscosity and the interfacial tension had great impacts on the droplet size. The effect of the nozzle diameter on the generated droplet size was small compared to that of the orifice in a CFF device. Using the simulation results, a correlation was also developed and suggested which predicts the droplet size with less than 15% error in a wide range of the introduced dimensionless parameters.     

炭毡的电镀及其在功能复合材料中的应用

对三种常见炭毡：ＰＡＮ基、粘胶基、沥青基炭毡进行了电镀Ｃｕｍ、Ｎｉ和Ｆｅ－Ｎｉ合金的研究,同时对镀镍、镀铜以及镀铁镍合金炭毡在电磁屏蔽材料、结构吸附材料和电池电极材料中的应用作了初步探讨。结果表明,使用适当的镀液和电镀工艺可以在炭毡纤维的表面上均匀地沉积金属镀层,ＰＡＮ基炭毡由于具有强度高,孔隙率高,易于沉积金属,在电磁功能材料领域具有广泛的应用前景。     

Preparation and mechanical characterization of chicken feather/PLA composites

Green composites, a bio‐based polymer matrix is reinforced by natural fibers, are special class of bio‐composites. Interest about green composites is continuously growing because they are environment‐friendly. This study describes the preparation and mechanical characterization of green composites using polylactic acid (PLA) matrix including chicken feather fiber (CFF) as reinforcement. Extrusion and an injection molding process were used to prepare CFF/PLA composites at a controlled temperature range. CFF/PLA composites with fiber mass content of 2%, 5%, and 10% were manufactured. The effects of fiber concentration and fiber length on mechanical properties of CFF/PLA composites have been studied. Mechanical properties of composites were investigated by tensile, compression, bending, hardness, and Izod impact testing. The results of experiments indicated that Young's modulus, compressive strength, flexural modulus, and hardness of the PLA reinforced CFF composites are higher but tensile strength, elongation at break, bending strength and impact strength of them are lower than pure PLA. The results indicate that these types of composites can be used for various applications. POLYM. COMPOS., 38:837–845, 2017. © 2015 Society of Plastics Engineers     

Molecular Iodine/Cyclophosphamide Synergism on Chemoresistant Neuroblastoma Models

Neuroblastoma (Nb), the most common extracranial tumor in children, exhibited remarkable phenotypic diversity and heterogeneous clinical behavior. Tumors with MYCN overexpression have a worse prognosis. MYCN promotes tumor progression by inducing cell proliferation, de-differentiation, and dysregulated mitochondrial metabolism. Cyclophosphamide (CFF) at minimum effective oral doses (metronomic therapy) exerts beneficial actions on chemoresistant cancers. Molecular iodine (I₂) in coadministration with all-trans retinoic acid synergizes apoptosis and cell differentiation in Nb cells. This work analyzes the impact of I₂ and CFF on the viability (culture) and tumor progression (xenografts) of Nb chemoresistant SK-N-BE(2) cells. Results showed that both molecules induce dose-response antiproliferative effects, and I₂ increases the sensibility of Nb cells to CFF, triggering PPARγ expression and acting as a mitocan in mitochondrial metabolism. In vivo oral I₂/metronomic CFF treatments showed significant inhibition in xenograft growth, decreasing proliferation (Survivin) and activating apoptosis signaling (P53, Bax/Bcl-2). In addition, I₂ decreased the expression of master markers of malignancy (MYCN, TrkB), vasculature remodeling, and increased differentiation signaling (PPARγ and TrkA). Furthermore, I₂ supplementation prevented loss of body weight and hemorrhagic cystitis secondary to CFF in nude mice. These results allow us to propose the I₂ supplement in metronomic CFF treatments to increase the effectiveness of chemotherapy and reduce side effects.     

Preparation of pseudocapacitor electrodes via electrodeposition of polyaniline on nonwoven carbon fiber fabrics

Aniline has been polymerized via electrodeposition onto various nonwoven carbon fiber fabric (CFF) substrates for use as a pseudocapacitive electrochemical capacitor. Four types of CFF were initially tested for double layer capacitance before polyaniline deposition, and again for specific capacitance after deposition. A binder‐free CFF was selected for further analysis due to its high capacitance change following PANI deposition (three orders of magnitude). The aniline monomer concentration, deposition potential, and deposition time were varied and resulting materials were characterized using chrono‐potentiometry, cyclic voltammetry, and scanning electron microscopy. The deposition potential range yielding highest capacitance was found to be between 0.744 and 0.777 V. A solution concentration of 0.5M aniline at a 20 min deposition time resulted in the highest specific capacitance (>80 F/g based on total electrode mass and >300 F/g based on PANI mass) within this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43315.     

ERG and Behavioral CFF in Light-Damaged Albino Rats

The full-field ERG is useful for index rod- or cone-mediated retinal function in rodent models of retinal degeneration. However, the relationship between the ERG response amplitudes and visually guided behavior, such as flicker detection, is not well understood. A comparison of ERG to behavioral responses in a light-damage model of retinal degeneration allows us to better understand the functional implications of electrophysiological changes. Flicker-ERG and behavioral responses to flicker were used to determine critical flicker frequency (CFF) under scotopic and photopic conditions before and up to 90 d after a 10-day period of low-intensity light damage. Dark- and light-adapted ERG flash responses were significantly reduced after light damage. The a-wave was permanently reduced, while the b-wave amplitude recovered over three weeks after light damage. There was a small, but significant dip in scotopic ERG CFF. Photopic behavioral CFF was slightly lower following light damage. The recovery of the b-wave amplitude and flicker sensitivity demonstrates the plasticity of retinal circuits following photopic injury.     

Rapid and low-cost carbon/carbon composites by using graphite slurry impregnated prepregs

A rapid and low-cost carbon/carbon (C/C) composites preparation method is proposed: graphite prepreg-coated carbon fiber fabric (CFF) is formed by hot pressing, followed by hot isostatic pressing and high temperature graphitization, to prepare C/C composite with low porosity and high crystallinity. In this method, the carbon fiber (CF) mass fraction can be precisely regulated in the range of 40–95% by the impregnation process conditions of CFF in graphite prepreg. The graphite particles in the preform were graphitized and bonded with CFF by high temperature graphitization. Finally, a ZrO₂ anti-ablative layer was applied using sol-gel method. The results show that when the CF mass fraction is 50%, the C/C composite with a crystallinity of 92.21 and a porosity of 3.47% can be obtained, with mass ablation rate of 0.23 mg/s and density of 1.62 g/m³. The method can prepare C/C composites with uniform density and high ablation resistance.     

Poly(lactic acid) composite films reinforced with microcrystalline cellulose and keratin from chicken feather fiber in 1-butyl-3-methylimidazolium chloride

Amphiphilic keratin from chicken feather fiber (CFF) and hydrophilic cellulose were incorporated as fillers into hydrophobic poly(lactic acid) (PLA) polymer blend. This study implemented ionic liquid (IL) of 1-butyl-3-methylimidazolium chloride (BMIMCl) to dissolve the 1 wt % fillers. The composite films were compared with and without the addition of IL prepared from five sets of ratios of CFF to MCC using measuring mixers and compression molding. Thermal analysis showed that increase in CFF composition decreases the glass-transition temperature (T _g), and crystallization temperature (T _c) as well as increases the degree of crystallinity. PLA composite with the 70/30 ratio of CFF to MCC was found to be the optimum composition in obtaining considerably low T _g and high crystallinity. BMIMCl enhanced the miscibility of the composites as observed in scanning electron microscope images and single T _g. Apart from creating porous structure and lowering mechanical hardness, BMIMCl also decreased the thermal stability of the PLA composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47642.