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921.
采用熔融共混法制备了尼龙6/苯乙烯-马来酸酐共聚物/N-苯基马来酰亚胺共混物(PA6/SMA/N-PMI),并利用DSC、TGA及力学性能测试等手段研究了SMA用量对PA6/SMA/N-PMI共混物熔融结晶行为、热学性能以及力学性能的影响。结果表明,共混物的最大分解温度较纯PA6有较大提高;SMA用量的增加,共混物的结晶温度、结晶度以及熔融焓均先降低再升高;当SMA用量为5份时,共混物的弯曲强度、弯曲模量以及热变形温度均达到最大值,分别为113.8、3 053 MPa及61.3℃,较纯PA6分别提高了25.1%、28.0%及19.0%;拉伸强度在SMA用量为7.5份时达到最大值81.4 MPa,较纯PA6提高了17.1%。 相似文献
922.
Catalysts Cu Ox/γ-Al_2O_3-IH and Cu Ox/γ-Al_2O_3-IM were prepared, characterized, and tested for styrene combustion in the absence and presence of water vapor. The effect of copper valence of the catalysts on the catalytic activity for styrene combustion was discussed using the theory of hard soft acids and bases(HSAB).The results showed that the existence of water vapor in feed stream inhibited the catalytic activity for styrene combustion due to the competition adsorption of water molecule. HSAB theory confirmed that the local soft acidity of the catalyst Cu Ox/γ-Al_2O_3-IH was much stronger than that of the catalyst Cu Ox/γ-Al_2O_3-IM because of the higher content of soft acid Cu+on its surface, which increased the adsorption ability toward soft base of styrene and reduced the adsorption toward hard base of water vapor, and thus increased the catalytic activity for styrene combustion and weakened the negative influence of water vapor. 相似文献
923.
924.
The influence of oxidizing environments on single crystal diamond and polycrystalline chemical vapor deposited CVD diamond films was studied using the near edge X-ray absorption fine structure (NEXAFS) pre-edge region in both bulk and surface sensitive modes. The NEXAFS of (100) oriented single crystal diamond was measured following (i) exposure to a microwave (MW) hydrogen plasma, (ii) annealing to 1000 °C, (iii) exposure of the as annealed surface to H2O, and (iv) exposure of the as annealed surface to O2. From these measurements particular surface bonding configurations have been assigned to features in the pre-edge structure. The NEXAFS of microcrystalline CVD diamond films was studied following different oxidative treatments using (i) a thermal atomic oxygen (AO) environment, (ii) a hyperthermal (5 eV) AO source, and (iii) an RF oxygen plasma exposure. The nature of the surface layer was found to be different for differently oxidized surfaces. These treatments were carried out as part of a study of CVD diamond durability in the low Earth orbit space environment. 相似文献
925.
P(N-phenylmaleimide-alt-styrene) (PNS) was synthesized, and nylon 6 (PA6)/PNS blends were prepared by melt blending. The heat resistant and crystallographic properties of PA6/PNS blends with different contents were investigated and analyzed. The results showed that the heat deflection temperature (HDT), relative crystallinity (Xn), and dynamic viscosity (η) increased with increasing PNS. The results of differential scanning calorimetry proved that PNS had played a positive role in nucleating PA6. Scanning electron microscosopy showed that the PNS domains were between 0.2 and 4 μm in diameter. The experimental results indicated that the addition of PNS improved the rigidity of PA6/PNS blends, thereby improving the heat-resistant properties of these blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47689. 相似文献
926.
对无烟煤水焦浆(APCWS)的成浆性与稳定性做实验研究,并进行工业化气化实验.结果表明,APCWS的表观黏度随石油焦加入量的增大而减小,萘系聚合物(NSP)的分散性优于磺化木质素(LS)的分散性,采用LS添加剂的APCWS稳定性更好;工业化气化实验结果显示,APCWS的气化温度、石灰石加入量和氧浆比都比精煤水煤浆(RCWS)的要低,气化活性较好,具有更高的碳转化率,气化渣中碳含量较RCWS气化渣中碳含量低,且气化渣颗粒性较好,较容易过滤;利用APCWS比RCWS浆吨氨气化原料成本降低,经济效益显著. 相似文献
927.
928.
929.
《Ceramics International》2016,42(12):13849-13854
Sm2Zr2O7 and (Sm0.5Sc0.5)2Zr2O7 ceramics were fabricated by a chemical co-precipitation and calcination method, and their hot corrosion behaviors in Na2SO4+V2O5 molten salt were investigated. Hot corrosion tests were carried at 700 °C, 800 °C and 900 °C for 4 h, and corroded surfaces were investigated using X-ray diffractometer and scanning electron microscopy. The corrosion products of Sm2Zr2O7 ceramics were composed of SmVO4 and monoclinic-ZrO2, while those of (Sm0.5Sc0.5)2Zr2O7 ceramic consisted of SmVO4 and Zr5Sc2O13. Considering the fact that Zr5Sc2O13 is more desirable than monoclinic-ZrO2 for thermal barrier coating applications, (Sm0.5Sc0.5)2Zr2O7 showed better corrosion resistance to Na2SO4+V2O5 salt than Sm2Zr2O7. The hot corrosion mechanisms of Sm2Zr2O7 and (Sm0.5Sc0.5)2Zr2O7 in Na2SO4+ V2O5 salt were discussed in detail. 相似文献
930.
采用基于密度泛函理论的全势线性缀加平面波方法,分别采用GGA和GGA+mBJ为交换关联势,对铜掺杂在稳定的六角纤锌矿结构氧化锌的电子结构和磁性进行了计算.由GGA计算得到的电子结构表明铜掺杂氧化锌是半金属材料,而GGA+mBJ计算得到的电子结构表明铜掺杂氧化锌不具有半金属材料特征,而是典型的磁性半导体材料,与Buchholz等的实验结果一致,相对于GGA近似计算,GGA+mBJ计算的结果更能反映材料的性质. 相似文献