〈数〉几何
3.The number concentration of the activated cloud condensation nuclei (CCN) is described with the hypergeometric function.
4.He constructed one geometric model,in which some infinite series with Catalan numbers as coefficients were contained.
5.Study on the reading method for the test of geometric precision of machine tool
6.This paper extends the T route counting of two-dimensional perpendicular space to the T route counting of n dimensional perpendicular(oblique) space(k≤n), and gives some concree formulas of counting when n=3,k=2,3; and gives some new geometry (combination) explanation of Catalan number.
7.The test results indicated that: crack similitude of reinforced concrete simple beams is not equal to model scale λ under the working load; when the amount and surface shape of reinforcing bar are same, the similitude of crack width, crack amount and crack spacing of reinforced concrete simple beams of different scales are all nearly equal to the square root of model scale√λ; when the amount and surface shape of reinforcing bar are different, the similitude of crack amount and crack spacing are still nearly equal to√λ, whereas the crack width is not only approximately proportional to√λ, but the influence of the amount and surface shape of reinforcing bar on crack width should be considered also at the same time.
8.Flow separation was observed on the expansion ramp at Mach 2.5.To improve off-design performance of single expansion ramp nozzles,variable geometry nozzle configuration should be adopted.
9.0.62±0.42(geometric mean)and 0.04±0.68(arithmet— ic mean)by regression of offspring on dam in sire; 0.77 by half—sib corr— elation in unit.
10.Under the condition of high Velocity flow ( v ≥ 50 m/s) on hydraulic structures the aerated flow may become superhigh speed flow which Mach number M equals or is more than 1 due to lower sound velocity in it. this paper presents possible fundamental equations of superhigh speed flow. On the base of analysis of these equations similarity criteria for the flow are obtained.
