Nonlinear dynamic characteristics and bifurcation analysis of Ti–Zr–Ni quasicrystal as hydrogen storage material

In this article, the nonlinear dynamic characteristics and bifurcation of a Ti–Zr–Ni quasicrystal impacted by hydrogen atoms are studied. New nonlinear damping terms are proposed to express the delay characteristics of Ti–Zr–Ni quasicrystal, and the accurate natural frequency is obtained by the harmonic balance method. A new method based on the developed largest Lyapunov exponent is proposed to analyze the local stability of any point in the system, and the system's global stability is determined. Finally, a new way to realize the switch between hydrogen storage and release based on stochastic Hopf bifurcation is proposed. The results of theoretical analysis and numerical simulation show that the system's motion can be switched between a periodic orbit and a balanced point near the bifurcation boundary with little energy consumption, which is helpful for hydrogen storage and release.     

Enhanced photo-electrochemical activity of ZnO/Cu2S nanotube arrays photocathodes

ZnO/Cu₂S nanotube arrays are fabricated firstly by a facile and capping-agent-free method, and the photo-electrochemical performance has been studied systematically. The results show that ZnO/Cu₂S nanotube arrays achieve enhanced photo-electrochemical water splitting performance and the photocurrent densities of ZnO/Cu₂S are 7.9 times than that of ZnO at 0 V versus Ag/AgCl. The performance of the ZnO/Cu₂S nanotube arrays can be adjusted by changing the amount of Cu₂S microcrystals. The results confirm that the enhanced photo-electrochemical performance of ZnO/Cu₂S is due to the significantly improved visible light absorption, effective separation of photo-induced carriers due to the well band energy match and the formed p-n junction between ZnO and Cu₂S.     

插值算法在内燃机瞬时转速测量中的应用研究

提出了采样信号的插值计算公式 ;考虑到测量信号中调制现象的影响 ,提出了插值法在瞬时转速计算中的误差公式 ;并针对 6 - 135 G柴油机最高转速对两点插值和三点插值的精度进行了计算 ;最后用实测数据进行了验证。结果表明这是提高瞬时转速测量精度的一种有效方法 ,在 5 0 k Hz的低采样率下即可得到较平滑的瞬时转速波形。     

NPT5型空气压缩机机油乳化的原因及对策

针对NPT5型空气压缩机机油乳化的惯性故障,分析了造成机油乳化的主要原因,提出了拆检空气压缩机出风管路逆止阀、检查气阀和活塞、安装自动排水阀和更换机油等预防措施,并提出了重新界定机油含水量标准、加强油质监控和使用添加剂的建议。     

超选择性肾动脉碘油－无水乙醇乳化液栓塞术治疗肾肿瘤

目的探讨肾动脉内碘油－无水乙醇混合物栓塞治疗肾肿瘤的效果。方法收集２０例肾脏恶性肿瘤和良性肿瘤,采用同轴微导管超选择性肾动脉插管,以容积比为２∶１的碘油－无水乙醇乳化液栓塞肾肿瘤供血血管各分支,术后４周复查肾动脉造影,酌情重复治疗,定期随访。结果１８例经一次栓塞肿瘤坏死彻底,栓塞后４周,肿瘤供血中断。其中肾癌及肾转移癌体积减小在５０％以上１３例,占８１．３％,碘油聚集良好;２例重复治疗１次,临床症状明显减轻。结论超选择性肾动脉碘油－无水乙醇乳化液栓塞术,可以在最大限度保护肾功能的前提下,在毛细血管水平栓塞肿瘤所有供血血管,达到永久性栓塞的效果,疗效肯定,值得推广。     

植入式给药装置对比外周静脉穿刺中心静脉置管应用于肿瘤患者长期静脉给药的卫生经济学分析

【摘要】 目的 对植入式给药装置（PORT）和外周静脉穿刺中心静脉置管（PICC）应用于肿瘤患者长期静脉给药的卫生成本和健康产出进行综合分析,阐述PORT相比PICC的卫生经济性。方法 采用回顾性文献研究和肿瘤患者问卷调查,基于社会视角,对PORT和PICC应用于患者长期静脉给药的成本和健康产出进行测算,并将质量调整生命年（QALYs）转换为货币单位,进行成本-效益分析。结果 由于价格差异,肿瘤患者静脉给药初期PORT的费用明显高于PICC,当全面计算各项卫生成本和健康产出时,给药3.9个月时两者净收益将持平,之后PORT的净收益都高于PICC且随着给药时间延长而不断提高。结论 肿瘤患者长期静脉给药中应用PORT的经济性优于应用PICC。

     

太阳能中温闪蒸海水淡化系统产水性能研究

为提高系统产水性能并降低内部结垢,提出一种由非跟踪复合抛物面聚光器加热导热油至100 ℃以上作为供能热源,采用喷雾辅助闪蒸的海水淡化系统。实验研究实际天气中,不同太阳辐照度下进水口温度、进水流量对系统产淡水性能的影响。采用密封压力桶可将进水口温度升至沸点以上,最高可达123 ℃。太阳辐照度波动较大时,进水口温度保持稳定,系统可稳定运行。进水口温度对产水速率影响显著,平均进水口温度从100 ℃升至120 ℃时,产水速率提高47.61%。当进水流量为50 kg/h,压力维持在0.045 MPa时,系统产水速率最大,日累计淡水产量可达11.14 kg/（d·m²）,小时效率为81.45%,单级生产率为9.15%。     

基于高速动态的颗粒气泡脱附过程动力学研究

通过颗粒气泡脱附高速动态测试系统,研究了颗粒气泡脱附过程动力学。运用Image-Pro Plus图像处理软件测量颗粒气泡间接触角、三相润湿周边,计算颗粒气泡间毛细黏附力随颗粒运动时间的变化。结果表明：颗粒从气泡表面脱附主要分为气泡拉伸变形接触角增大和气泡滑动三相润湿周边减小两个阶段。气泡拉伸阶段,三相润湿周边固定在颗粒表面,接触角由平衡接触角增大到前进接触角;气泡滑动阶段,接触角保持不变,三相润湿周边滑动减小。毛细黏附力在气泡脱附过程中随接触角增大而增大,随三相润湿周边滑动而减小,当外力超过颗粒气泡间临界黏附力时,颗粒从气泡表面脱附。     

基于改进PID的风电探测控制系统设计

为了改善风电探测控制效果,设计基于改进PID的风电探测控制系统。系统采用风电场探测处理单元搭建探测控制装置,利用改进PID划分风电工况区,控制工况区内的荷载,标定回波探测范围,优化探测控制系统回波特性,从而实现风电探测控制系统的设计。仿真测试表明,设计系统可以获得理想的风电探测效果,风电探测控制误差小,具有实际应用价值。     

Mechanism of Hg<Superscript>0</Superscript> oxidation in the presence of HCl over a CuCl<Subscript>2</Subscript>-modified SCR catalyst

CuCl₂-SCR catalysts prepared by an improved impregnation method were examined to evaluate the catalytic activity for gaseous elemental mercury (Hg⁰) oxidation in the presence of HCl at the typical SCR reaction temperature of 350 °C. It was found that Hg⁰ oxidation activity of commercial SCR catalyst was significantly improved by the introduction of CuCl₂. The X-ray fluorescence and Hg⁰ temperature-programmed desorption (Hg⁰-TPD) methods were employed to characterize the catalysts. The results indicated that CuCl₂ on CuCl₂-SCR catalyst could release active Cl species in the presence of O₂ at 350 °C, and the released active Cl species could be replenished in the presence of gas-phase HCl. CuCl₂-SCR catalyst possessed the appropriate active sites for the adsorption of NH₃ and HCl, which could scavenge the inhibiting effect of NH₃ on Hg⁰ oxidation. Hg⁰-TPD results suggested that the oxidized mercury compounds mainly exited as HgCl₂ once HCl was present. The Hg⁰ oxidation mechanism over CuCl₂-SCR catalyst in the presence of HCl could be explained as follows: The adsorbed Hg⁰ reacted with active Cl species released by CuCl₂ to form HgCl₂. The reduced CuCl was re-chlorinated to CuCl₂ via the intermediate copper oxychloride (Cu₂OCl₂) formation by being exposed to the gas-phase HCl.