http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Wang Weikai (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Wang Weikai,Cai Yi-xi,Shi Yunxi,Wang Jing,Zhao Nan,Ji Liang 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.4
A non-thermal plasma (NTP) reactor was used to generate ozone for diesel particulate filter (DPF) regeneration. The kinetic mechanism of ozone thermal decomposition reaction is explored, and the effect of temperature on the change of ozone concentration is analyzed. The changes of the internal temperature and the concentration of regeneration products such as CO2 and CO during the regeneration under constant temperature and non-constant temperature conditions are then studied and the influence of different regeneration environments on the regeneration is analyzed in combination with the decomposition law of ozone. In the non-constant temperature condition, DPF surface temperature changes significantly with time. The results show that when using an NTP reactor to generate ozone, the activation energy of the decomposition reaction is 2.80755 × 104 J/mol and the law of thermal decomposition reaction can be described as 190.76 . /. During DPF regeneration, the overall regeneration rate and ozone utilization rate in the nonconstant temperature environment are higher than in the constant temperature environment and the temperature change (delta-T) peak rises with the increase of PM deposition. The regeneration with NTP under non-constant thermal condition is an effective way to improve the efficiency of DPF regeneration.
-
Li, Weikai,Wang, Zhengxia,Zhang, Limei,Qiao, Lishan,Shen, Dinggang Frontiers Media S.A. 2017 Frontiers in neuroinformatics Vol.11 No.-
<P>Functional brain network (FBN) has been becoming an increasingly important way to model the statistical dependence among neural time courses of brain, and provides effective imaging biomarkers for diagnosis of some neurological or psychological disorders. Currently, Pearson's Correlation (PC) is the simplest and most widely-used method in constructing FBNs. Despite its advantages in statistical meaning and calculated performance, the PC tends to result in a FBN with dense connections. Therefore, in practice, the PC-based FBN needs to be sparsified by removing weak (potential noisy) connections. However, such a scheme depends on a hard-threshold without enough flexibility. Different from this traditional strategy, in this paper, we propose a new approach for estimating FBNs by remodeling PC as an optimization problem, which provides a way to incorporate biological/physical priors into the FBNs. In particular, we introduce an L<SUB>1</SUB>-norm regularizer into the optimization model for obtaining a sparse solution. Compared with the hard-threshold scheme, the proposed framework gives an elegant mathematical formulation for sparsifying PC-based networks. More importantly, it provides a platform to encode other biological/physical priors into the PC-based FBNs. To further illustrate the flexibility of the proposed method, we extend the model to a weighted counterpart for learning both sparse and scale-free networks, and then conduct experiments to identify autism spectrum disorders (ASD) from normal controls (NC) based on the constructed FBNs. Consequently, we achieved an 81.52% classification accuracy which outperforms the baseline and state-of-the-art methods.</P>
-
Gradient folding metasurfaces with simultaneous phase and amplitude modulation
Zibin Lin,Weikai Xu,Wei Wang,Shasha Yuan 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12
An elastic metasurface with a gradient index of functional units, namely gradient folding metasurface (GFMS), is proposed to simultaneously manipulate the transmission phase and amplitude of flexural waves. By varying the gradient index common ratio (CR) between each adjacent unit, the GFMS was found to cover an entire 2π span of phase shift. At the same time, the amplitude of the transmitted flexural wave can also be modulated. Based on the generalized Snell's law, two different cases of the wave focusing effect are realized, which illustrate CR dependent wave propagation mode from symmetric to asymmetric and verify the ability of the proposed metasurface to manipulate complete elastic wave through simultaneous phase and amplitude modulation. This study expands phase-amplitude modulation from acoustics to elastic waves and provides more degrees of freedom in elastic metasurface designing.
-
Zhao Nan,Cai Yi-xi,Shi Yunxi,Wang Weikai,Ni Sijia 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5
The objective of this study was to evaluate the effects of lubricating oil age on the generation of diesel particulate filters (DPF) by non-thermal plasma (NTP) technology and to characterize the physical properties of ash. The regeneration status was evaluated by the concentration of regeneration products and regeneration temperature. The compositional and morphological characteristics of ash were analyzed by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Compared with DPF@L-fresh, the internal regeneration temperature was reduced in DPF@L-age. The unit removal time of carbon was 39.23 min/g for DPF@L-fresh but was reduced to 34.87 min/g for DPF@L-age, which indicated that the efficiency of NTP regeneration increased. Shorter regeneration time and lower airflow resistance caused by NTP technology aided the formation of a unique chain-type ash with the structure of a hollow column. Several fine particles that had formed by the condensation of volatiles were distributed on the ash surface of the aged lubricant, and the ash clusters were loosely combined. TEM images revealed that ash was mostly composed of a crystal structure, that the ash dimension of aged lubricant decreased, and that the adhesion between ash particulates was weak.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
