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1.
《International Journal of Hydrogen Energy》2022,47(94):39931-39942
A dual-coolant integrated experimental facility named DRAGON-V has been developed at the Institute of Nuclear Energy Safety Technology, Hefei Institute of Physical Science, Chinese Academy of Sciences, for the key technology research and performance evaluation of candidate liquid lithium-lead (PbLi) blanket of hydrogen fusion reactors. The loop is composed of a material test sub-loop and thermal-hydraulic test sub-loop, the design parameters are PbLi inventory 20 tons, PbLi temperature up to 550 °C, the maximum PbLi flow rate up to 40 kg/s. A novel cold trap system is designed to remove the suspended and crystalized impurities in PbLi fluid with three cooling zones and cross row arrangement of rod bundle filter elements. The paper describes the loop itself and its major components, initial loop testing, flow and measurement diagnostics and current experiments. The obtained test results of the loop and its components have demonstrated that the new facility is fully functioning and ready for experimental studies of material corrosion with/without a magnetic field, magnetohydrodynamic (MHD) effect, purification, heat and mass transfer phenomena in PbLi flows and can also be used in mock-up testing in conditions relevant to fusion applications. 相似文献
2.
永磁无刷直流电机是近些年发展起来的一种新型电机,具有效率高、调速性能好、启动转矩大等诸多优点,在运动控制领域中的应用日趋广泛。基于电机专用控制芯片MC33035,采用单片机C8051F500为主控芯片,设计一款无刷直流电机智能控制器,实现对无刷直流电机启动停止、正反转、调速、转速显示等控制。通过简要介绍无刷直流电机工作原理,使用MATLAB/Simulink对控制系统进行建模仿真,对无刷直流电机控制系统进行软、硬件设计。实验结果表明,该控制系统运行稳定,抗干扰性强,具有良好的市场应用价值。 相似文献
3.
ABSTRACT Supply chains are becoming increasingly complex, and many companies and researchers are looking to nature for finding solutions. In this paper, we provide a narrative synthesis and systematic review to explore state-of-the-art, and identify key areas for exploration of nature inspired solutions in the supply chain area. We consider strategic, tactical, and operational decisions within supply chains and identify analogies between biological systems and supply chains to create a new research agenda. Our findings show that the majority of the research in nature inspired supply chains from the systemic perspective focuses on closed loop supply chains. In contrast, similar systemic solutions such as industrial symbiosis, circular economy, and industrial ecology have not been explored as frequently. Reducing production waste (industrial symbiosis) in addition to end-of-life product waste (closed loop supply chains), optimising raw material use and extending the life of used resources (circular economy), investigating the interactions between biosphere and technosphere (industrial ecology), and seeking solutions to industrial problems from nature (biomimicry) are all possible paths for reaching a zero-waste economy. These systemic solutions have a considerable impact on the supply chains at the strategic, tactical, and operational levels, which need to be explored to identify efficient and effective solutions. 相似文献
4.
环路热管作为一种高效的相变传热装置,其性能与位于蒸发器和储液槽之间的毛细芯结构密切相关。为了更深入研究双层毛细芯对环路热管传热性能的影响,利用不同颗粒直径铜粉制备双层毛细芯,在毛细芯总厚度为5 mm的条件下,通过调整大粒径和小粒径层的相对厚度来改变毛细芯厚度比,对平板型蒸发器环路热管启动和变工况运行进行实验测试。实验结果表明:在同一工况下,不同厚度比的双层毛细芯启动特性存在显著差异,启动过程中出现小粒径层蒸发效率低引起的温度过冲和环路热管中气液两相流变化导致的温度振荡;同时存在一个较优的双铜层毛细芯厚度比,大粒径(180~280μm)铜层厚度为3 mm可提高蒸发效率,小粒径(56~71μm)铜层厚度为2 mm可提供足够毛细抽吸力保证环路热管稳定运行。搭载该厚度毛细芯的环路热管不仅启动速度快(125 s),而且总热阻和蒸发器壁面温度均最低,最大加热功率达到120 W(21.10 W/cm~2),对应热阻为0.17 K/W。 相似文献
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6.
菜豆环氧化物水解酶1和2(PvEH1、PvEH2)能够动力学拆分外消旋邻甲基苯基缩水甘油醚(rac-oMGE),从而保留(R)-oMGE。基于对PvEH1和PvEH2结构的同源模拟和分析,发现二者分子中的盖子环差异较大,故本文选择盖子环作为研究目标。经融合聚合酶链式反应(FPCR),获得了PvEH2的盖子环区域被PvEH1对应区域替换的杂合酶Pv2Pv1。用全细胞酶E. coli/pv2pv1催化rac-oMGE,当(S)-oMGE刚好水解完全时,产物(S)-3-邻甲苯基-1,2-丙二醇((S)-oTPD)的eep由PvEH2的58.3%提高至75.5%。为进一步提高酶的性质,在Pv2Pv1中选取11个氨基酸位点进行丙氨酸(A)突变,获得最优突变子E. coli/pv2pv1K176A,活性为E. coli/pv2pv1(4.2U/g)的2.1倍,且当S构型的底物刚好完全水解时,(S)-oTPD的eep进一步提高为80.3%。分子对接分析发现,盖子环替换和K176位点突变为A,均使(R)-oMGE环氧环中的Cα更易受到酶中D101位点的攻击。利用E. coli/pv2pv1K176A催化150mmol/L rac-oMGE水解制备(R)-oMGE(ees>99%)和(S)-oTPD(eep=80.4%),二者的产率YS和YP分别为32.7%和60.1%,时空产率STYS和STYP为1.6g/(L·h)和3.3g/(L·h)。本实验为改善EH的催化性质提供了一种有效策略。 相似文献
7.
Changbai Long Huiqing Fan Wei Ren Jinyan Zhao 《Journal of the European Ceramic Society》2019,39(14):4103-4112
This work reports the existence of double polarization hysteresis (P–E) loop in Aurivillius-phase ferroelectric Bi4Ti3O12 (BiT) and reveals dramatic influence of small compositional variations on the electrical properties of it. The double polarization hysteresis is a characteristic of the interaction of defects with domain walls. This characteristic becomes more pronounced in Bi-deficient and Mg-doped BiT due to an increase in oxygen vacancy concentration at the lattices. Normal and saturated P–E loop is recalled by Nb donor doping, and associated composition Bi4Ti2.97Nb0.03O12.015 (BiT-0.03Nb) shows high remnant polarization (Pr = 12.5 μC/cm2) and large field-induced strain (S33 = 5.6 × 10?4). In addition, this doping results in bulk conductivity (σb) of BiT decreasing dramatically and associated activity energy (Ea) increasing significantly. In contrast, high oxide ion conductivity is induced with Mg2+ acceptor doping, and at 600 °C the optimum composition has ionic conductivity of ?0.65 × 10?2 S cm?1 in the bulk. 相似文献
8.
Journal of Computer Science and Technology - DOACROSS loops are significant parts in many important scientific and engineering applications, which are generally exploited pipeline/wave-front... 相似文献
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10.
This study deals with linear and weakly non-linear stability analyses of Brinkman–Bènard convection in nanoliquid-saturated porous enclosures. Water with a dilute concentration of molybdenum disulfide nanoparticles with 0.06 volume fraction and 30% glass fiber-reinforced polycarbonate as a porous medium with porosity 0.88 are considered to be a working medium. The analytical solution is obtained in the present study for idealistic and realistic boundary conditions, and their results are compared. An analytically intractable Lorenz model with quadratic nonlinearities is reduced to a tractable Ginzburg–Landau amplitude equation with cubic nonlinearity using the multiscale method. Nanoparticles with different shapes are considered in the study, and their effects on the onset and heat transfer are discussed in great detail graphically in the presence of other parameters arising in the problem. 相似文献