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1.
A finite reaction rate model is presented as a closure of large eddy simulation (LES) to numerically study an open premixed methane/air swirling flame. The resultant model is firstly validated by comparing with reported data and then employed to investigate the effect of swirling intensity on flow field, flame characteristics and combustion instability of the swirling flame. Three differ- ent swirl numbers are considered. The LES results show that as swirling intensity increases, the vortex entrainment and micro-mixing are enhanced, leading to more lean equivalent ratios at flame front; consequently, higher swirling number causes lower flame temperatures and slower CO oxidization; for all simulated swirl numbers, flame fronts are completely located out of the recirculation zones and anchored at the inner surface of the annular swirling steams; swirl number has a crucial effect on swirling flame extension toward radial and tangential dimensions and then significantly affects streamwise flame length, which is a great influencing factor on combustion instability; vortex-induced disturbance on flame in streamwise plays a critical role in combustion instability. 相似文献
2.
The radiation decay of a two-level atom could be inhibited within structured environments even under longtime evolution. We investigate the stabilized quantum coherence of composite systems undergoing local dissipation and exploit it further as a resource for remote state preparation. We focus on outputs of quantum states with solely quantum discord (i.e., without entanglement) and demonstrate that they could be resulted from various initial states providing specific spectral structure of the reservoir. In detail, we elaborate the behavior of stabilized quantum discord and the corresponding fidelity for remote state preparation in connection with structural spectra of Ohmic class reservoir and of photonic band gap mediums. 相似文献
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4.
提出一种适用于混合域累加的16级时间延迟积分(Time Delay Integration,TDI)型CMOS图像传感器的电流型累加器.为了实现混合域的累加,电流信号首先在电流型累加器中累加4次,累加的结果被量化成数字量后再次完成4次的累加,即4×4的混合累加模式.详细分析了电流型累加器的热噪声和闪烁噪声特性,并给出了等效输入噪声的均方根电压表达式,并结合仿真工具进行分析验证.提出的电流型累加器电路在CMOS180nm 1.8V供电电源的工艺下实现,电路的功耗为0.37mW,芯片面积为0.03mm×0.82mm.经过电流型累加器的4次累加后,能够将信号的信噪比提升5.86dB. 相似文献
5.
在整个定点着舰过程中,飞机着舰下滑阶段的操纵难度和危险系数都是最高的,如何解决光学导引仿真中模型的准确度和视景特效的逼真度。是定点着舰仿真应用的重中之重。为了解决上述问题,根据光学导引秉统成像原理以及飞机、舰之间的几何关系,实时计算光学下滑道,建立了仿真平台的数学模型,并给出了状态方程。在基于VP平台的视景系统中,采用“立体光面”和动态缩放光晕的方法建立菲涅尔助降灯阵和迎角指示器的模型,保证了模拟着舰过程中飞行员视觉的逼真度。以美F-16飞机模型,进行了多次计算机仿真着舰,试验数据表明:在理想条件下光学导引仿真平台模型正确可信,飞行员着舰质量明显提高,能够起到导引着舰的作用。 相似文献
6.
屈服面的位置和形状直接影响材料塑性应变的确定。考虑滑移是晶体的主要塑性变形机制,介绍了晶体塑性理论的推广--滑移构元模型,研究了应力空间和应变空间的后继屈服面演化。给出了确定应力空间和应变空间屈服面的数值计算方法,提出一种考虑屈服面畸变变形的混合硬化假设,可以描述应力空间和应变空间后继屈服面的移动和畸变变形。通过计算1100-O 铝在纯扭转和拉扭组合加载下(σ11 -σ12)空间和(ε11 -γ12)的后继屈服面演化,与已有实验结果吻合。研究结果表明,无论是在应力空间还是应变空间,后继屈服面“前凸后扁”的变形特征可基于滑移构元的潜在硬化和包氏效应来描述。 相似文献
7.
Direct numerical simulation is employed to investigate the premixed jet flame of methane in lean, combined with a detailed chemical kinetics including 17 species and 58 elemental steps and distinct Lewis numbers. Cold methane-air mixture at 0.55 equivalence ratio is injected into the coflow area with 9500 Reynolds number. The coflow ambient gas is set to be the burnt gas of the methane-air mixture in main jet and temperature is assigned to be the corresponding adiabatic flame temperature 1515 K. The whole s... 相似文献
8.
Guo-qiang Liu Xi Wang Ya-jie Gao Lei Wen Guang-yin Liu Jian-jie Zheng Peng Cen Ying Li 《矿物冶金与材料学报》2012,19(5):457-460
Spinel compounds LiNi0.5Mn1.3Ti0.2O4 (LNMTO) and Li4Ti5O12 (LTO) were synthesized by different methods. The particle sizes of LNMTO and LTO are 0.5–2 and 0.5–0.8 μm, respectively.
The LNMTO/LTO cell exhibits better electrochemical properties at both a low current rate of 0.2C and a high current rate of
1C. When the specific capacity was determined based on the mass of the LNMTO cathode, the LNMTO/LTO cell delivered 137 mA·h·g−1 at 0.2C and 118.2 mA·h·g−1 at 1C, and the corresponding capacity retentions after 30 cycles are 88.5% and 92.4%, respectively. 相似文献
9.
The multi-stage humidifier semi-dry flue gas cleaning technology, the CRS plasma flue gas cleaning technology and oxidative additive flue gas cleaning technology were investigated for multi-pollutants removal. The semi-dry flue gas cleaning technology using multistage humidifier and additive can improve oxidation and absorption, and it can achieve high multi-pollutants removal efficiency. The CRS discharge can produce many OH radicals that promote NO oxidation. Combining NaOH absorption can achieve high deSO2 and deNOx efficiencies. It is very fit of the reconstruction of primary wet flue gas desulfurization (WFGD). In addition, Using NaClO2 as additive in the absorbent of WFGD can obtain very high removal efficiency of SO2 and NOx. 相似文献
10.
通过收集16例急性非淋巴细胞白血病(ANLL)病人的血清和外周血白血病细胞条件培养液(LCM),对血清和LCM中的白血病相关抑制物(LAI)对正常人T淋巴细胞集落(CFU-TL)形成的影响进行研究。发现16例病人的LAI对正常人CFU-TL均有抑制作用,而缓解期病人的LAI抑制作用甚弱。追踪观察11例病人:其中抑制率高于30%的6例患者治疗效果差;抑制率低于25%的5例患者治疗效果较好,达到完全缓解或部分缓解。结果提示ANLL病人的细胞免疫功能缺陷与LAI的存在有关。 相似文献