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1.
A least‐squares meshfree method based on the first‐order velocity–pressure–vorticity formulation for two‐dimensional incompressible Navier–Stokes problem is presented. The convective term is linearized by successive substitution or Newton's method. The discretization of all governing equations is implemented by the least‐squares method. Equal‐order moving least‐squares approximation is employed with Gauss quadrature in the background cells. The boundary conditions are enforced by the penalty method. The matrix‐free element‐by‐element Jacobi preconditioned conjugate method is applied to solve the discretized linear systems. Cavity flow for steady Navier–Stokes problem and the flow over a square obstacle for time‐dependent Navier–Stokes problem are investigated for the presented least‐squares meshfree method. The effects of inaccurate integration on the accuracy of the solution are investigated. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
2.
Seulah Lee Man Hyung Koo Dong-Won Han Il-Chan Kim Jun Hyuck Lee Jeong-Hoon Kim Razia Sultana Sun Yeou Kim Ui Joung Youn Jin-Hyoung Kim 《Molecules (Basel, Switzerland)》2022,27(14)
Total fatty-acid (FA) contents of different organs (stomach, liver, brain, and skin) of two Antarctic fish, marbled rockcod (Notothenia rossii) and mackerel icefish (Champsocephalus gunnari), were examined using gas chromatography–mass spectrometry (GC–MS). N. rossii possessed higher contents of total omega-3, where eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the most represented omega-3 FAs, were distributed throughout all parts of the fish. The highest level of EPA was observed in the skin and that of DHA was observed in the brain of N. rossii. C. gunnari showed organ peculiarity in that most of the omega-3 FAs were found in stomach and skin. Specifically, the highest levels of EPA and DHA were both observed in the stomach. Although N. rossii and C. gunnari both inhabit the Antarctic Southern Oceans, their characteristics in terms of the composition of fatty acids were shown to vary. The extracts were also evaluated for matrix metalloproteinase-1 (MMP-1)-inhibitory activities in UVB-induced human dermal fibroblasts, where extracts of the skin and liver of N. rossii showed the most significant inhibition upon MMP-1 production. These findings provide experimental evidence that the extracts of the Antarctic fish could be utilized as bioactive nutrients, particularly in the enhancement of skin health. 相似文献
3.
4.
In this paper, high-luminance yellow-emitting Y3Al5O12:Ce3+ phosphor (YAG:Ce) microparticles were prepared in a solid flame using a 1.425Y2O3+2.5Al2O3+0.15CeO2+k(KClO3+urea)+mNH4F precursor mixture (here k is the number of moles of the KClO3+urea red-ox mixture, and m is the number of moles of NH4F). The self-sustaining combustion process for the entire reaction sample was provided by the heat generated from the KClO3+urea mixture. Parametric studies demonstrated that the maximum temperature in the combustion wave varied from 885 to 1200 °C for k=2.0-3.0 mole and m=0-1.5 mole. X-ray analysis results showed that the product obtained in the solid flame consisted of Y3Al5O12:Ce3+ and KCl phases. Therefore, after dissolving potassium chloride in distillated water, pure-phase YAG:Ce phosphor powder was obtained. The as-prepared YAG:Ce phosphor particles had diameters of 10-25 μm and good dispersity and exhibited luminescence properties comparable to those of YAG:Ce phosphor powders prepared by conventional high-temperature processing. 相似文献
5.
We have investigated the inverted poly (3-hexylthiophene):methano-fullerene [6,6]-phenyl C71-butyric acid methyl ester (P3HT:PC71BM) bulk heterojunction (IBHJ) solar cell with various n-type metal oxide nano particle layers on ITO and MoO3 anode buffer layer underneath Al. The IBHJ solar cell with a tin oxide nano particle layer shows the power conversion efficiency (PCE) of 3.1% and better stability compared to conventional BHJ solar cell. The PCE of this cell decreases by 3% after 2 months in ambient air while the other cells show more degradation. 相似文献
6.
7.
We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ~ 35 dB). The generated PDL value could be maintained within ± 0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520nm ~ 1590 nm. 相似文献
8.
As borders between different entities, lines are an important element of natural images. Indeed, the neurons of the mammalian
visual cortex are tuned to respond best to lines of a given orientation. This preferred orientation varies continuously across
most of the cortex, but also has vortex-like singularities known as pinwheels. In attempting to describe such patterns of
orientation preference, we are led to consider underlying rotation symmetries: Oriented segments in natural images tend to
be collinear; neurons are more likely to be connected if their preferred orientations are aligned to their topographic separation.
These are indications of a reduced symmetry requiring joint rotations of both orientation preference and the underlying topography.
This is verified by direct statistical tests in both natural images and in cortical maps. Using the statistics of natural
scenes we construct filters that are best suited to extracting information from such images, and find qualitative similarities
to mammalian vision.
PACS84.35+i 89.70.+c 87.57.Nk 相似文献
9.
10.
Pressure reducing valves are widely used to maintain the pressure of gas reservoirs to specific values. In a normal valve,
supply pressure is decompressed with an orifice structure. When compressed air passes through the orifice structure, considerable
noise occurs at the downstream side. In this paper, we have developed a radial slit structure that can reduce pressure without
noise. The noise is reduced by changing the orifice structure into the radial slit structure. The radial slit structure valve
reduces pressure without noise by suppressing the generation of turbulence and shock wave at the downstream. The analysis
of the flow in radial slit structure was achieved by CFD2000 software. The flow rate and pressure distribution were simulated
and compared with the experimental result. To confirm the generation of shock wave, the flow of orifice and radial slit structure
at the downstream was visualized by Schlieren photography method. A shock wave was generated in the orifice structure, but
no shock wave was generated in the radial slit structure. Noise reduction efficiency was investigated by the experiment. The
experiment apparatus was set up to JIS standards. The experimental results indicated that the noise level decreased by approximately
40 dB in the slit structure. It is confirmed that the radial slit structure has effectiveness for low noise in the pressure
reducing flow. And, it is expected that it can be applied to various kinds of industrial fields. 相似文献