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为了探究出新型车用热泵空调系统制冷剂R1234yf的最佳充注量,进一步提升系统制冷性能。本文以搭建的准二级压缩型热泵空调系统为研究对象,通过实时记录系统参数变化,对系统的制冷性能进行分析。结果表明:在制冷剂R1234yf充注量为550 g时,系统的制冷量和COP分别达到最高值6.34 kW、2.63,排气温度降低到最低值77.8℃;并且在充注量为550 g时,系统的过冷度与过热度出现交汇,此时系统的制冷性能最佳,系统运行最稳定。 相似文献
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SCR烟气脱硝系统的脱硝率由喷氨量来控制,而喷氨流量控制系统控制喷氨量,因此,优化喷氨流量控制系统能有效提高脱硝率。设计了一种基于变论域的模糊控制器来实现喷氨量的优化控制,并采用 MATLAB 仿真软件对此控制方案进行仿真,并与传统的控制方案的结果进行对比分析。结果表明,基于变论域的模糊控制喷氨流量系统相对于传统的PID控制,其超调小,且鲁棒性较强,有效地提高了控制品质。 相似文献
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《中国物理快报》2016,(4)
We theoretically study the spin transport through a two-terminal quantum dot device under the influence of a symmetric spin bias and circularly polarized light.It is found that the combination of the circularly polarized light and the applied spin bias can result in a net charge current.The resultant charge current is large enough to be measured when properly choosing the system parameters.The resultant charge current can be used to deduce the spin bias due to the fact that there exists a simple linear relation between them.When the external circuit is open,a charge bias instead of a charge current can be induced,which is also measurable by present technologies.These findings indicate a new approach to detect the spin bias by using circularly polarized light. 相似文献
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利用热刺激放电(Thermally Stimulated Discharge, TSD)电流谱、在线电荷TSD、电荷等温衰减测量和衰减全反射(Attenuated Total Reflection, ATR)红外光谱分析,本文系统地研究了经化学表面处理(萃取、氧化及氢氟酸)的聚丙烯(PP)孔洞驻极体膜的电荷储存稳定性及电荷稳定性提高的原因.结果表明:经适当地氧化和氢氟酸室温处理试样的TSD电流谱中在温位约为184℃处出现原膜所没有的非常强的新峰,电荷热稳定性得到显著的提高,这一电荷热稳定性通过高温充电工艺得到进一步地改善;适当延长室温下氢氟酸处理的时间或延长氧化时间,都会使处理膜的电荷稳定性得到提高.理论分析表明在线电荷TSD测量法可给出线性升温过程中电荷重心及驻极体电荷量变化的综合信息,结合TSD电流谱和初始电荷重心位置的测量,可精确地考察线性升温过程中电荷重心的在线变化.
关键词:
聚丙烯孔洞膜
表面氧化
氢氟酸处理
电荷稳定性
在线电荷TSD 相似文献
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As technologies scale down in size, multiple-transistors being affected by a single ion has become a universal phenomenon, and some new effects are present in single event transients (SETs) due to the charge sharing collection of the adjacent multiple-transistors. In this paper, not only the off-state p-channel metal-oxide semiconductor field-effect transistor (PMOS FET), but also the on-state PMOS is struck by a heavy-ion in the two-transistor inverter chain, due to the charge sharing collection and the electrical interaction. The SET induced by striking the off-state PMOS is efficiently mitigated by the pulse quenching effect, but the SET induced by striking the on-state PMOS becomes dominant. It is indicated in this study that in the advanced technologies, the SET will no longer just be induced by an ion striking the off-state transistor, and the SET sensitive region will no longer just surround the off-state transistor either, as it is in the older technologies. We also discuss this issue in a three-transistor inverter in depth, and the study illustrates that the three-transistor inverter is still a better replacement for spaceborne integrated circuit design in advanced technologies. 相似文献
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采用基于MS(Materials Studio)软件和密度泛函理论的第一性原理方法, 研究了HfO2 俘获层的电荷俘获式存储器(Charge Trapping Memory, CTM)中电荷的保持特性以及耐擦写性. 在对单斜晶HfO2中四配位氧空位(VO4) 缺陷和VO4 与Al替位Hf掺杂的共存缺陷体(Al+VO4)两种超晶胞模型进行优化之后, 分别计算了其相互作用能、形成能、Bader电荷、态密度以及缺陷俘获能. 相互作用能和形成能的计算结果表明共存缺陷体中当两种缺陷之间的距离为2.216 Å时, 结构最稳定、缺陷最容易形成; 俘获能计算结果表明, 共存缺陷体为双性俘获, 且与VO4缺陷相比, 俘获能显著增大; Bader电荷分析表明共存缺陷体更有利于电荷保持; 态密度的结果说明共存缺陷体对空穴的局域能影响较强; 计算两种模型擦写电子前后的能量变化表明共存缺陷体的耐擦写性明显得到了改善. 因此在HfO2俘获层中可以通过加入Al杂质来改善存储器的保持特性和耐擦写性. 本文的研究可为改善CTM数据保持特性和耐擦写性提供一定的理论指导. 相似文献
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An improved, more general method for performing multicentred integrated QM/QM calculations is presented. The new approach allows the multicentred approximation to be extended to overlapping model systems, removing a significant limitation of the original approach. The usefulness and numerical accuracy of the equations presented are confirmed via some applications to dipole–dipole, charge–dipole and charge–charge complexes. The method performs well for all of these complexes, which range from very weakly to very strongly bound and in which non-additivity effects on interaction energies range from 0.2 to 17kcalmol?1. 相似文献