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高体积分数SiCp/Al复合材料的热物理性能 总被引:5,自引:0,他引:5
采用无压渗透法制备了高体积分数SiCp/Al复合材料,用XRD对复合材料的物相进行了分析,测定了SiCp/Al复合材料在25~200℃温度区间的热膨胀系数及热导率,运用理论模型对复合材料的热膨胀系数以及热导率进行了计算,并探讨了热物理性能与温度之间的关系。结果表明,高体积分数SiCp/Al复合材料具有较低的热膨胀系数、高的热导率,综合热物理性能优良。 相似文献
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Shiqiang Lu Baozhong Shang Zijian Luo Renhui Wang Fangchang Zeng 《Journal of Materials Science》1999,34(22):5449-5456
The effect of the thermal exposure at different temperatures on the microstructure is investigated for MP159 alloy by optical microscopy and transmission electron microscopy (TEM). Thermal exposure at 660°C is related to the aging induced hardening mechanism, thermal exposure at the neighborhood of 920°C is associated with static recrystallization behavior, and thermal exposure at a temperature range of 920 to 1070°C for a short time is investigated with a view toward obtaining the longest permissible thermal exposure time during which microstructural reconstitution of the cold deformed microstructure would not occur at the corresponding temperature, which would provide guidance for determining reasonable hot forging parameters of fasteners. The results indicate that both solution heat treated (ST) and cold worked (CW) MP159 alloy could be hardened by aging. This aging induced hardening is attributable to the precipitation of a very finely dispersed fcc ordered solid solution. The precipitating process is so rapid that the air cooling (AC) or water cooling (WC) process of the sample exposed to elevated temperature higher than normal aging temperature could produce an appreciable hardening effect. The recrystallization temperature of the alloy is as high as 920°C, such a high recrystallization temperature is attributed to deformation twins and a variety of alloying elements due to their inhibition to the nucleation and growth of recrystallization grains, other than to the hcp-phase which used to be believed to explain high recrystallization temperature in MP alloys in some literature. 相似文献
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电镀企业清洁生产审核第四部分电镀企业清洁生产指标体系与评价 总被引:1,自引:0,他引:1
明确了电镀企业建立清洁生产指标体系的原则,从原辅材料与资源能源、污染物产生、产品和环境经济效益等方面建立了电镀企业清洁生产指标体系,探讨了企业清洁生产水平与绩效的评价方法。 相似文献
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《Materials Letters》2005,59(19-20):2412-2417
High quality poly (5-nitroindole) (PNP) films were synthesized electrochemically by direct anodic oxidation of 5-nitroindole in boron trifluoride diethyl etherate (BFEE) containing additional 10% diethyl ether (by volume). The additional diethyl ether improved the solubility of the monomer in BFEE. In this medium, the oxidation potential onset of 5-nitroindole was measured to be only 1.04 V vs. SCE. PNP films obtained from this medium showed good electrochemical behavior with conductivity of 10− 2 S cm− 1. Structural studies showed that the polymerization of 5-nitroindole ring occurred at 2,3 position. As-formed PNP films could be dissolved in acetone, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), etc. Fluorescent spectral studies indicated that PNP was a good green light emitter with the best excitation and emission wavelength of 420 and 550 nm, respectively. To the best of our knowledge, this is the first time that nitro group-substituted high-quality conducting polymer films can be electrodeposited. These results will be greatly helpful for the understanding of the synthesis and properties of nitro-substituted conducting polymers and provide a new route for the post-functionalization of nitro-substituted conducting polymers through the reduction of nitro group. 相似文献
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MSM9811是OKI公司生产的4通道混合语音合成芯片。他可以选择直接8b PCM,非线性的8b PCM,4bADCPCM和4b ADPCM2语音格式并且提供了两通道的立体音输出及音量控制。介绍了MSM9811语音芯片的引脚功能、接口命令以及具体使用方法。同时给出了用AT89C52与MSM9811构成的语音系统的硬件设计和相应的软件编程。 相似文献
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