Published in Science in China Series G: Physics Mechanics and Astronomy
Abstract In this paper, for the measured surface with the characteristics of continuous radiation, we put forward the general model of the spectral emissivity with non- dimensional wavelength. In the analysis process, based on the Taylor series expansion, we theoretically discuss the applicable conditions of the model. Further, introducing the conc...
Published in Science in China Series G: Physics Mechanics and Astronomy
Laminar-turbulent transition is an old yet unsolved problem. Notwithstanding the great effort made, there is an important question that seems not to have been addressed yet, that is, what is the inherent mechanism of breakdown that eventually leads to transition? The conventional idea is that the transition starts from the amplification of disturba...
Published in Science in China Series G: Physics Mechanics and Astronomy
This paper presents a stress controlled boundary slip model and predicts the fluid-solid interface slip in a system of parallel sliding plates or a sphere approaching a smooth plane. The numerical simulation results are in striking agreement with the existing experimental observations. This model assumes that there is a limiting shear stress. No sl...
Published in Science in China Series G: Physics Mechanics and Astronomy
Zinc nitride (Znb3Nb2) powder has been synthesized through the nitridation reaction of Zn powder with NH3 gas (at the flow rate of 500 ml/min) at the nitridation temperature of 600 for 120 min. X-ray diffraction (XRD) indicates that Znb3Nb2 is cubic in structure with the lattice constant being a = 0.9788 nm. Scanning electron microscopy (SEM) and t...
Published in Science in China Series G: Physics Mechanics and Astronomy
The quasi-one-dimensional nonlinear monoatomic lattice is analyzed. The kink-soliton and antikink-soliton are presented. When the interaction of the lattice is strong in the x-direction and weak in the y-direction, the two-dimensional (2D) lattice changes to a quasi-one-dimensional lattice. Taking nearest-neighbor interaction into account, the vibr...
Published in Science in China Series G: Physics Mechanics and Astronomy
Utilizing linear optical devices, the principle of B92 quantum key distribution (QKD) protocol is demonstrated in free space with a distance of transmission of 2.2 meters. The faint laser pulses with 650 nm wavelength are used as the single photon sources. The experimental results show that the eavesdropping behavior in the signal transmission can ...
Published in Science in China Series G: Physics Mechanics and Astronomy
Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the e...
Published in Science in China Series G: Physics Mechanics and Astronomy
We present a large scale map of about 15′ × 15′ of CO(J=1−0) toward W51 giant molecular cloud (GMC), which covers the most active star-forming region of W51 GMC, and an interferometry HCO+(J=1−0) map of a high spatial resolution (i.e. 8″ × 6″.1) with a field of view (2′ × 2′) centered at W51IRS1. A structure model of W51GMC is obtained according to...
Published in Science in China Series G: Physics Mechanics and Astronomy
We present interferometric observations of the W51 region at 2.7 mm and 3.3 mm with the Berkeley-Illinois-Maryland Association Array. The lines of CH3CN (J = 6 − 5, K = 0,1,2,3,4), CH3OH (15−2−151 E), HCOOCH3-A (71,6 − 615), HCOOCH3-E (71,6 − 615) and 13CS (2-1) as well as the 2.7 mm continuum toward W51 have been observed. The derived total beam-a...
Published in Science in China Series G: Physics Mechanics and Astronomy
This paper reports on the synthesis of the nanocrystalline FeS2 via a solvent-thermal process. Using FeSO4 and NH2CSNH2 as precursors and polyvinyl-pyrrolidone (PVP) as a protective agent (dispersant), we have successfully synthesized nanocrystalline FeS2 both under acidic conditions (pH = 5) and under alkali conditions (pH = 10) at various tempera...
