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971.
972.
应用Monsanto加工性能试验机(MPT)对胎面胶进行压出流变试验。在实验条件下,考察试样熔体的流动特性及其影响因素,并作初步的分析和讨论。实验发现,试样的流动曲线可近似用指数方程描述;而熔体粘度对温度的依赖性则大体上符合Arrhenius方程。 相似文献
973.
High surface area carbon-supported platinum-based catalysts, Pt/C, PtWO
x
/C, PtRu/C and PtRuWO
x
/C, were prepared via a chemical reduction route using single metal precursor salts. The catalyst particles were found to
be in the nanoscale range, and the addition of Ru clearly decreased the particle size. The Ru was found to be partially incorporated
into the face centered cubic lattice of Pt and to form a single Ru catalyst component. X-ray diffraction and X-ray photon
spectroscopy did not provide evidence for electronic interactions between WO
x
and Pt as well as WO
x
and Ru. However, the addition of tungsten to the PtRuWO
x
/C catalyst resulted in a high degree of catalyst particle agglomeration. Both Ru containing catalysts showed significantly
higher activities for the CH3OH oxidation reaction in terms of Pt + Ru mass as well as electroactive Pt + Ru surface area than the Pt/C and PtWO
x
/C catalysts. The addition of tungsten appeared to mainly result in some ‘physical’ modification of the catalytically active
Pt and Ru surface components such as differences in electroactive surface area rather than promotion of the CH3OH oxidation reaction via a true catalytic mechanism. 相似文献
974.
Possible use of methylbenzenes as electrolyte additives for improving the overcharge tolerances of Li-ion batteries 总被引:1,自引:0,他引:1
Based on the voltammetric behaviour of a series of methyl-substituted benzenes in 1M LiPF6/EC-DMC electrolyte, xylene was selected and tested as an electrolyte additive for overcharge protection of Li-ion batteries. From the overcharge curves, CV behaviour and SEM observations of the cells in the presence of xylene, it was found that the additive can polymerize at the overcharged voltage to form a dense layer of isolating polymer film at the cathode surface, which blocks off further oxidation of the electroactive material and electrolyte and, therefore, improves the overcharge tolerance of the Li-ion battery. In addition, the xylene additive has shown only a slight influence on the cycling behaviour. 相似文献
975.
浆态床中合成二甲醚的研究 总被引:1,自引:0,他引:1
考察了浆态床中3种甲醇合成催化剂反应行为,考察了温度、压力、催化剂比例和种类对二甲醚合成的影响.结果表明,低压下甲醇合成催化剂中C30l活性最好,温度降低和压力升高有利于甲醇的合成.二甲醚合成中,不同脱水催化剂反应性能不同.在考察范围内,温度升高,CO转化率变化不大,二甲醚的选择性增加;压力升高,CO转化率和二甲醚选择性都随之升高;两种催化剂(C301Hβ)的质量比为41时,CO转化率和二甲醚选择性最高. 相似文献
976.
977.
978.
深水表层钻井随钻压力与温度监测装置是监测深水表层钻井过程中井底当量循环密度(ECD)和循环温度的重要工具。通过深水表层钻井随钻压力与温度监测装置,现场技术人员可以实时掌握井下环空压力、钻柱内压和温度等工程参数,进而了解和分析井下工况,为深水表层钻井作业和动态压井钻井技术提供指导。设计的深水表层钻井随钻压力与温度监测装置以ARM为核心,利用数据采集技术和通信技术,实现了随钻压力与温度的采集传输。完成的深水表层钻井随钻压力与温度监测装置具有体积小、功耗低、抗振动和抗高温和低温的优点。监测装置已经在我国南海第一口深水井LW6—1—1井的领眼井中成功进行应用试验,验证了其在深水无隔水管钻井条件下的机械强度、稳定性、可靠性,测量得的数据能真实反映钻井工况。 相似文献
979.
提出一种基于FPGA的视频跟踪系统硬件平台的设计方法,包括主控芯片、CMOS图像采集、多端口SDRAM控制器、图像VGA显示、SOPC系统和云台控制驱动等电路的设计。通过该平台,可以实现实时图像采集、缓存、显示和云台驱动;在SOPC系统中加入代码,可以实现运动目标的检测、跟踪、定位,改变云台转动方向,实现自主跟踪。 相似文献
980.
In this study, linear low‐density polyethylene films were produced using different processes (film blowing and biaxial orientation) and processing conditions. The orientation of the films was characterized in terms of their biaxial crystalline, amorphous, and global orientation factors using birefringence, tilted incidence polarized Fourier Transform Infrared Spectroscopy (FTIR), and X‐ray diffraction pole figures. Evaluation of a simplified FTIR procedure without the use of the tilted method for the determination of crystalline orientation factors proposed in the literature is also evaluated and assessed. The results indicate that FTIR overestimate the crystalline orientation factors, particularly for the crystalline a‐axis. Significant discrepancies are also observed for the b‐axis orientation, which may be due to an overlap of the amorphous phase contribution. Those differences are larger for films with low orientation, such as blown films. Amorphous phase orientation from FTIR depends on the band used and is not necessarily in agreement with that determined from the combination of X‐ray and birefringence. The simplified FTIR procedure is proven to be inadequate in the case of linear low‐density polyethylene blown films studied having a random lamellar crystalline morphology. POLYM. ENG. SCI. 46:1182–1189, 2006. © 2006 Society of Plastics Engineers. 相似文献