초 록
멧누에는 실내에서의 대량사육이 곤란한 것으로 알려져 왔으나 부화에서부터 100%가까운 다습상태와 전후의 고온사육조건에서 간단히 사육할 수 있었다. 실내사육결과 전령경과일수는 15~25일의 범위이며 대부분의 유충은 17일 전후이었다. 용화비율은 약40%이며 용기간은 암수모두 13~25일 사이였다. 또한 암수모두 2개의 우화최고점을 가지며 수컷이 암컷에 비해 2~3일정도 빨리 우화하였다.
The tidal radii of globular clusters reflect the tidal field of the Galaxy. The mass distribution of the Galaxy thus may be obtained if the tidal fields of clusters are well known. Although large amounts of uncertainties in the determination of tidal radii have been obstacles in utilizing this method, analysis of tidal density could give independent check for the Galactic mass distribution. Recent theoretical modeling of dynamical evolution including steady Galactic tidal field shows that the observationally determined tidal radii could be systematically larger by about a factor of 1.5 compared to the theoretical values. From the analysis of entire sample of 148 globular clusters and 7 dwarf spheroidal systems compiled by Webbink (1985), we find that such reduction from observed values would make the tidal density (the mean density within the tidal radius) distribution consistent with the flat rotation curve of our Galaxy out to large distances if the velocity distribution of clusters and dwarf spheroidals with respect to the Galactic center is isotropic.
들깨잎말명나방의 실내누대사육을 위해 누에 인공사료를 기본으로 하여 들깻잎분말을 30, 40, 50% 함유한 3종의 평판형사과(구, 구, 구)를 공시, 기주식물인 들깻잎으로 사육한 PL구를 대조로 비교사육시험한 결과, 인공사료육구가 생엽육구에 비해 번데기 및 성충수율이 높았으며 또한 번데기무게도 무거웠다. 특히 들깻잎분말 40%를 함유한 사료구의 사육성적이 비교적 우수하여 이에 의한 실내누대사육체계를 확립하였다.
인공사료에 의한 실내사육에서 부활율은 97.9%, 3령까지의 생존율은 83.3%였다. 3령유충에서의 용활율은 톱밥을 이용한 집단사육에서 82.5%, 개체사육에서 48.5%, 집단사육에서 37.5%로서 톱밥을 이용한 집단사육에서 가장 높았다. 유화율은 톱밥을 이용한 집단사육에서 90.9%, 개체사육에서 85.2%, 집단사육에서 86.7%로 거의 비슷하였다. 톱밥을 이용한 집단 사육법은 개체사육법에 비하여 사육방법이 용이하고 인공사료의 양을 줄일 수 있다.
The initial mass functions (IMF) of 15 selected open clusters are investigated by making use of C-M diagrams and theoretical evolutionary tracks. Among 15 clusters 13 have peaks in their IMFs and it is thought to be not due to incomplete photometry but to intrinsic property. The mass where IMF peaks is about 2 M ⊙ and it is similar to that of the second peak in the IMF of nearby field stars. The mean slope of the IMF in the high mass part is 1.9 ± 0.6 with some variations among clusters. But there seems to be no correlation between the slope and physical parameters such as ages, diameters, and metal abundances.
We present recent data of absolute measurements of flux emmitted in the visible continua of some galactic Wolf-Rayet stars, carried out by means of a two-channel scanner built up cooperatively by the Observatoire de Lyon and the Laboratoire d'Astronomie Spatiale. Our measurements lead to the determination of stellar angular diameters which enable us to compute log L∗/L⊙ L∗/L⊙ and to locate the WR stars in the HR diagram: The WR stars are cooler than the zero age main sequence (ZAMS) and the WN7, WN8 types appear more luminous than other subclasses. The stellar wind terminal velocities, V∞ V∞ , deduced from the empirical relation of the effective temperatures by Underhil1(1983) and V∞ V∞ adopted from the work of Willis(1982) show about 2,000km/s. We derived the rate of mass loss for the program stars from the formula, ˙ M=ε(Teff)L/V∞⋅c M˙=ε(Teff)L/V∞⋅c by using the obtained effective temperatures, luminosities and V∞ V∞ in this work. Their values range from ˙ M=1.4×10−5 M˙=1.4×10−5 to ˙ M=5.8×10−5 ˙ M⊙/yr M˙=5.8×10−5M˙⊙/yr .
Luminosity profile of the late type spiral galaxy NGC 2403 was obtained using the PDS scan of the plate. Some physical parameters (scale length, total magnitude, central brightness, disk to bulge ratio and concentric indices) were calculated from the brightness distribution. Total mass and the mass to luminosity ratio were estimated from the fitting of various mass models.
담배거세미나방핵다각체병바이러스대량생산연구에서, 5영충에 1.1×107다각체/ml로 접종 후 8일에 수확했을 때 한 마리당 6.7×109 다각체를생산할 수 있었으며, 이때 통과는 한 마리당 약 2g의 인공통과로 충분하였다. 합성유약 호르몬인 methoprene (Manta˚ledR)을 처리했을 때 종영유충기간이 1~2일 연장되었으며, 바이러스 생산에 있어서도 무처리에 비해 약 15% 증가되었다.
We have considered the mass loss effects on the analytical PMS stellar evolutionary model of Stein(1966). In this calculation, we have assumed the mass loss law, M˙=K(L/C)(R/GM)'-,which should be reasonable for PMS stellar wind mechanism. The numerically obtained evolutionary tracks in H-R diagram indicate that the higher mass losses PMS star have, the later they reach the radiative equilibrium. We have considered the composition effect on the evolution such as the composition difference between Pop. I and Pop. II PMS stars. We have also compared the tracks under the mass loss law, M˙=K'LR/GM.
Combining the luminosity functions of main sequence stars in 3 associations and 22 open clusters, the initial luminosity function and mass function for these clusters are derived. For stars of m > 0.6 m ⊙ , they are well consistent with those for the field stars.
We study the luminosity and mass functions of open clusters using the data published by the United States Navel Observatory to figure out the relationships between these functions and the cluster ages. Slope ranges of the luminosity (dlogN/dMv) and mass function (-dlogN/d(log m/m@)) are 0.09-0.52(avg.=0.26, var.=0.01), 0.43-5.49(avg.=1.7, var.=0.63) respectively. These large ranges do not support the mass function is universal, but the function is time dependent. Despite of the poor relationship between the luminosity function and the cluster age, we obtain a good relationship in the mass function. We can understand this good relationship with a viewpoint of stellar evolution. We do age analyses in terms of the metal abundance and the number density of the open clusters. We get the fact that the less metal abundances and the less number densities, the more steep in the slopes of the mass function.
The Wielen dip over the ragne of 6 < M υ < 9 in the luminosity function (LF) for the solar neighborhood stars could be explained by the combination of two different IMFs which yields the age of 13 billion years of the solar neighborhood. This smaller age than the Galactic age, 15 billion years indicates the slow collapse model of the Galaxy, solving the G-dwarf problem. Two different IMFs suggest two different mechanisms for star formation in the solar neighborhood.
Dynamical conditions for the fronts around the Yellow Sea Cold Water Mass, were investigated by means of the oceanographical data and simple numerical experiment. The coastal front developed along the coast inside the Yellow Sea and distinguished the Yellow Sea Cold Water Mass from the coastal water is attributed to the predominant tidal mixing near the coast. On the other hand the southern part of the front of the cold water mass would be explained a a part of the extention of a western boundary current which flows into the Cheju Channel.
From the kinematically unbiased sample of halo stars, the local mass density of halo dwarfs is estimated as 6.0 ∼ 6.3 × 10 − 4 m ⊙ / p c 3 by adopting a color-magnitude relation and a mass-luminosity relation. The derived halo mass density is not much different from the results of previous studies, which were derived from the kinematically biased sample of halo stars. Therefore it is confirmed that the local mass density of halo stars is far less than that required by Ostriker-Peebles to stabilize the galactic disk against barlike instabilities.