两种花鲈(Lateolabrax sp.)耳石形态的地理变异

以耳石宽/耳石长（W/H）、主叶斜长/耳石长（L/H）、侧叶斜长/耳石长（l/H）、核宽/耳石宽（ow/W）、主叶宽/耳石宽（w/W）、主叶长/耳石长（h/H）、侧叶宽/主叶宽（w＇/w）、主叶宽/主叶长（w/h）、核宽/核长（ow/oh）、核长/第一年年轮直径（oh/D）为具体形态学分析参数,比较了鲈鱼、花鲈的舟山、福州、厦门和广西近海群体耳石的形态学特征.结果表明,鲈鱼与花鲈耳石形态、耳石重-耳石长的关系差异显著;聚类分析显示鲈鱼与花鲈舟山、福州、厦门、广西群体间的欧氏距离分别为4.538、5.656、5.396、4.670,花鲈各群体间欧氏距离在2.108-4.566之间.认为中国近海不同海域的花鲈群体耳石形态具有显著的地理变异,谨慎提出前述中国近海的花鲈分为三个不同的地理种群,即舟山种群、福州-厦门种群和广西种群的可能性.     

CCD photometry of the Galactic globular cluster M13

In this paper, we present a B − V CCD colour–magnitude diagram (CMD) of the globular cluster M13 (NGC 6205), reaching down about 2 mag below the main sequence turn-off, based on a new, independent photometric calibration.
The most notable features of the CMD, including about 5500 stars, are (i) the long extension of the blue tail of the horizontal branch (HB), which can be traced down to V ∼19 and (moreover) shows the presence of two gaps; and (ii) the so-called bump on the red giant branch which is well-detected at V =14.75±0.05, using both the differential and integral luminosity functions.
No similar features have ever been detected in any previous ground-based photometry of this cluster.
A direct comparison between the CMD of M13 and M3, calibrated during the same run with the same apparatus, sets an upper limit of about 1.5 Gyr on their age difference, too small to explain the striking differences between their HB morphologies.     

Towards the absolute planes: a new calibration of the bolometric corrections and temperature scales for Population II giants

We present new determinations of bolometric corrections and effective temperature scales as a function of infrared optical colours, using a large data base of photometric observations of about 6500 Population II giants in Galactic globular clusters (GGCs), covering a wide range in metallicity (−2.0 < [Fe/H] < 0.0).   New relations for BC _K versus ( V  −  K ) , ( J  −  K ) and BC _V versus ( B  −  V ), ( V  −  I ), ( V  −  J ), and new calibrations for T _eff, using both an empirical relation and model atmospheres, are provided.   Moreover, an empirical relation to derive the R parameter of the infrared flux method as a function of the stellar temperature is also presented.     

Nuclear burning rates and Population II stellar models

We discuss theoretical predictions concerning the evolution of globular cluster Population II stars with respect to current estimates of standard errors in the determination of nuclear burning rates. Numerical evaluations are given for the dependence of the turn-off and horizontal branch luminosities on the rate of the relevant nuclear reactions. We conclude that evolutionary predictions appear rather solid in this respect, with a maximum 3 σ error of about 1 Gyr in the evaluation of cluster ages derived from the calibration of the difference in luminosity between the horizontal branch and the turn-off. However, current evaluation of the original He content, as given on the basis of the R -parameter, will need to wait for a much better determination of the ¹²C(α, γ)¹⁶O reaction before reaching a satisfactory accuracy.     

人口预测方法及可靠性探讨

运用曲线拟合和灰色系统理论对我国人口发展进行预测，并对预测结果进行可靠性检验。     

人口地理学的研究进展

本文系统回顾了国外及我国人口地理学的发展过程和研究现状与趋势，并指出了我国的人口地理学研究与西方发达国家之间存在的主要差距，以及我国人口地理学今后发展的主要方向。     

The sequential megafaunal collapse hypothesis: Testing with existing data

Springer et al. [Springer, A.M., Estes, J.A., van Vliet, G.B., Williams, T.M., Doak, D.F., Danner, E.M., Forney, K.A., Pfister, B., 2003. Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling? Proceedings of the National Academy of Sciences 100 (21), 12,223–12,228] hypothesized that great whales were an important prey resource for killer whales, and that the removal of fin and sperm whales by commercial whaling in the region of the Bering Sea/Aleutian Islands (BSAI) in the late 1960s and 1970s led to cascading trophic interactions that caused the sequential decline of populations of harbor seal, northern fur seal, Steller sea lion and northern sea otter. This hypothesis, referred to as the Sequential Megafaunal Collapse (SMC), has stirred considerable interest because of its implication for ecosystem-based management. The SMC has the following assumptions: (1) fin whales and sperm whales were important as prey species in the Bering Sea; (2) the biomass of all large whale species (i.e., North Pacific right, fin, humpback, gray, sperm, minke and bowhead whales) was in decline in the Bering Sea in the 1960s and early 1970s; and (3) pinniped declines in the 1970s and 1980s were sequential. We concluded that the available data are not consistent with the first two assumptions of the SMC. Statistical tests of the timing of the declines do not support the assumption that pinniped declines were sequential. We propose two alternative hypotheses for the declines that are more consistent with the available data. While it is plausible, from energetic arguments, for predation by killer whales to have been an important factor in the declines of one or more of the three populations of pinnipeds and the sea otter population in the BSAI region over the last 30 years, we hypothesize that the declines in pinniped populations in the BSAI can best be understood by invoking a multiple factor hypothesis that includes both bottom–up forcing (as indicated by evidence of nutritional stress in the western Steller sea lion population) and top–down forcing (e.g., predation by killer whales, mortality incidental to commercial fishing, directed harvests). Our second hypothesis is a modification of the top–down forcing mechanism (i.e., killer whale predation on one or more of the pinniped populations and the sea otter population is mediated via the recovery of the eastern North Pacific population of the gray whale). We remain skeptical about the proposed link between commercial whaling on fin and sperm whales, which ended in the mid-1960s, and the observed decline of populations of northern fur seal, harbor seal, and Steller sea lion some 15 years later.     

Aspects of the distribution, population structure and reproduction of the gastropod Tibia delicatula (Nevill, 1881) inhabiting the oxygen minimum zone of the Oman and Pakistan continental margins

The present study describes some aspects of the distribution and biology of Tibia delicatula (Nevill), a gastropod belonging to the family Strombidae. This species has been found in large numbers in the upper oxygen minimum zone (OMZ) of the Oman margin, and has also been collected from the OMZ of the Pakistan margin. The highest abundance of adult specimens in the Oman OMZ was found between 300 and 450 m. Numbers dropped rapidly below 450 m, to zero below 500 m depth. Similarly dense populations were not observed in the Pakistan OMZ. Multiple regression with oxygen concentration and depth indicates that depth (and its related variables) is the main factor explaining the variation in abundance of T. delicatula. The populations from the Oman and Pakistan OMZs were dominated by juveniles. This suggests a unimodal size structure with evidence of a marked recruitment event. Basic reproductive aspects were analysed. All specimens had a penis and sperm groove. The gonad wall consisted of reticular tissue that might be used for nutrient storage or as an irrigation system. Only vitellogenic oocytes were present. The large oocyte sizes observed (200–300 μm) suggest a lecithotrophic larval development.     

资源、人口与产业结构对广东区域经济的影响

分析全省不同地区的区域特点、人口素质及产业结构,认为自然资源的基础作用、政策的导向作用造成省内经济发展的不平衡及人口素质和产业结构的分化,这种分化又反过来影响了经济的发展,加剧了这种不平衡.当经济发展到一定阶段后政府有责任、义务和条件促进区域协调发展,因为市场机制并不具有自动削减贫富差距、促进社会公平的功能,要实现市场导向作用下的区域经济协调发展,离不开地方政府对市场的合理调控.     

Marginalisation and demographic change in the semi-arid Karoo, South Africa

Semi-arid areas are often considered to be environmentally and economically marginal, a situation which has been exacerbated by economic change, shifts in agricultural production and land use, and changing state policy. These themes are explored with reference to a semi-arid landscape, namely the Karoo, which covers some 40% of the geographic space of South Africa and is used primarily for extensive livestock farming. Despite long-term decline in agricultural output, the traditional mainstay of the region, and weakening small town economies, the Karoo's population and the economies of its largest service centres are growing. There are, real socio-economic needs and development backlogs, and the situation has been exacerbated by recent political marginalisation. In this study, the small towns of the region are focal points of investigation and provide a lens to investigate the changing demographic and economic dynamics of the Karoo. Most of the region's population lives in these centres which are service, collection, and distribution points for what traditionally has been an agriculture-based regional economy. This paper explores the concept of marginalisation with specific reference to historical, economic, and demographic change.