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991.
The hot tearing susceptibility of MgZn_(4.5)Y_xZr_(0.5)(x = 0.5, 1, 2, 4, 6) alloys was evaluated using ClyneDavies' theoretical model and a constrained rod casting(CRC) apparatus equipped with a load cell and data acquisition system. The results obtained from these two approaches were in good agreement, illustrating that the hot tearing susceptibility of the investigated alloys is in the order of MgZn_(4.5)Y_xZr_(0.5) MgZn_(4.5)Y_xZr_(0.5) MgZn_(4.5)Y_xZr_(0.5) MgZn_(4.5)Y_xZr_(0.5) MgZn_(4.5)Y_xZr_(0.5). The microstructure and morphology of hot tearing regions were observed by means of X-ray diffraction and scanning electron microscopy. The function curves on variation of contraction force and temperature versus time were recorded by a computer during solidification of the MgZn_(4.5)Y_xZr_(0.5) alloys in a "T" type mold after A/D(Analog to digital) conversion. Results show that both the amount and morphology of the second phases have a great relationship with the hot tearing susceptibility. But the former plays a more important role on that of MgZn_(4.5)Y_xZr_(0.5) alloys. The role of low-melting point eutectic phases on the hot tearing susceptibility of MgZn_(4.5)Y_xZr_(0.5) alloys changes gradually with different Y contents. When Y ≤ 1wt.%, it is mainly a damaging effect on intergranular bonding force; when Y 1wt.%, it is mainly an intergranular feeding effect on formed separated dendrites. 相似文献
992.
993.
Yuzhi Zhou Linxia Zhang Lixia Qin Shi-Zhao Kang Xiangqing Li 《International Journal of Hydrogen Energy》2021,46(54):27495-27505
A mixed phase LaVO4 with high dispersion was in situ induced and implanted in graphene oxide-graphite carbon nitride composite. The obtained nanocomposite (GO–C3N4–LaVO4) showed high and stable photocatalytic activity for hydrogen evolution, which significantly benefited from the improved charge separation and light absorption in the special composite photocatalyst as evidenced by UV–vis spectra, fluorescence spectrum, photocurrent response and electrochemical impedance. The fabrication strategy of mixed phase LaVO4 in the GO-C3N4 provides a new idea for constructing cheap and active organic-inorganic semiconductor photocatalysts for hydrogen generation. 相似文献
994.
995.
996.
Exergy analysis is used as a tool to evaluate exergy losses in the steam-water jet injector so as to improve its overall performance.
What this article addresses here is mainly about a parametric study on the injector under various operating conditions, such
as different inlet water temperature, inlet steam pressure, pressure ratio, entrainment ratio and flowrate ratio. In addition,
the irreversible losses in the component parts of the two-stage injector were analyzed in detail. The results show that the
operating parameters have great effects on exergy efficiency of the injector. The average exergy efficiency of the two-stage
injector is 21% more than that of the single-stage one. Moreover, calculations based on experimental data indicate that the
highest exergy losses due to irreversibility occur in the first-stage mixing chamber. In light of this comparison, the exergy
losses occurring in the system are proportional to the exergy efficiency obtained by applying the system. 相似文献
997.
变性淀粉以其良好的适应性应用于食品、造纸、纺织、医药、轻工业、建材、石油、生物工程等行业,近年来受到越来越多的研究者的关注。基于Patent Strategies专利分析系统,对全球和中国变性淀粉专利技术进行专利授权、布局、技术来源、竞争力、IPC分类等角度的分析,在挖掘该研究领域核心专利的基础上,进一步分析变性淀粉领域的核心专利情况。该分析可为变性淀粉企业及研发人员提供重要参考。 相似文献
998.
Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric. 相似文献
999.
1000.