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91.
The article is dedicated to the problems of survival and development among the aboriginal peoples of northern Russia in the context of current conditions. Data collected in the western art of the Taimyr Autonomous District allowed us to divide the non-sedentary population of this territory into three groups differentiated by overall way of life, land use and economic "calendar." These groups are: the nomadic reindeer herders of the tundra (about 250–300 people), the semi-nomadic fishermenherders of Yenisei delta (about 500), and the nomadic herders of the forest-tundra (300–350). The economy and ways of life of the three non-sedentary groups are are described. Communities whose traditional subsistence base is reindeers have entered a crucial period. In response to the pressure of the dominant society, these peoples have three ossible strategies: isolation, passive adaptation and active adaptation. Only the last strategy can preserve their culture, and create a "neoculture". Now, however, passive adaptation predominates. The mutual, bi-directional process of cultural integration needs to reinforce positive aspects of acculturation and promote active, rather than passive, adaptation. A necessary condition for this is the appearance among the Nenets of an intermediate social stratum which maintains close links to nomadic reindeer-husbandry and is simultaneously integrated into the dominant society.  相似文献   
92.
The system of factors affecting the spatial distribution of the retail trade and service establishments has changed dramatically since socialist times. The administrative regulation lost its almost complete dominance and turned into one of the market forces. In contrast, the impact of the urban environment under very free market conditions substantially increased. We show the main directions of this influence. Two generalized indicators that we use describe macro trends in the development of the spatial system of retail trade and services. One of them, which we call the urban morphology, is of a concentric effect, another – transportation pattern – adds the sectoral component to the retail trade and services geography. Five systems of spatial attractions differently affect the distribution of different branches.  相似文献   
93.
地球磁场的新模型(英文)   总被引:2,自引:1,他引:2  
根据地球内核存在有相对于外核的旋转,这里提出一个地球磁场的新模型。在这种场合下,地球磁场的本源就是电流,这种电流是由在地核团相与液相边界上的一对带电层的相对运动产生出来的(Bullen地球模型中的F层)。所提出的模型,是当前最为常见的水磁发电机模型的另一种可供选择的模型。它在能量方面已得到确证。借助该模型,有可能去解释在地表观察到的关于磁场的所有主要特性。该模型的本质,就在于它是维持地球现今磁场与构造运动的统一机制。这种统一性并不是偶然的,可以将其视为所研究现象本质的理论的最大可能性证据。  相似文献   
94.
Different natural metrizations by Hölder type on the five dimensional space of Keplerian elliptic orbits are introduced. Certain applications of topological and metrical properties of the space of Keplerian elliptic orbits to several problems of Celestial Mechanics are discussed.  相似文献   
95.
Global change has become a major ecological concern that has the potential to dramatically alter plant distributions and assemblages worldwide. The specific response of plants to global change will depend on their ability to move, evolve, or adjust through phenotypic plasticity. Advances in biogeographic research are on the verge of a giant leap forward if we can take advantage of emerging tools in genetics and genomics. In this review, we appraise how new, post-Sanger, high-throughput sequencing and associated technologies can be used by next generation biogeographers to assess plant responses to global change. First, we briefly review the recent advances in genome sequencing and available approaches of genomic analysis. Secondly, we discuss the three main plant responses to global change: migration, adaptation, and phenotypic plasticity. This review is intended to spark the interest of biogeographers who do not traditionally use genetics but could benefit from including genetic and genomic tools into their research. Our goal is to illustrate that their use can contribute to new perspective and add an additional level of resolution into future biogeographic research.  相似文献   
96.
97.
We studied the difference in behavior of total energy and its thermal component during the radiative cooling of partially ionized hydrogen gas. Our calculations were fulfilled for the conditions in the atmosphere of a cool star. It is shown that the attenuation of total energy loss does not interfere with the cooling rate.  相似文献   
98.
99.
Several metric spaces of Keplerian orbits and a set of their most important subspaces, as well as a factor space (not distinguishing orbits with the same longitudes of nodes and pericentres) are constructed. Topological and metric properties of them are established. Simple formulae to calculate the distance are deduced. Applications to a number of problems of Celestial Mechanics are discussed.  相似文献   
100.
The first systematic model series of hulls with small waterplane area (both single hulls and twin-hulls) was designed and tested in Krylov Shipbuilding Research Institute in the middle of the 1980's. The series was intended to cover a broad range of Froude numbers, hull aspect ratios, design drafts, and spacing between hulls. In the present paper, these test results are re-analyzed by accounting for the scale effect in the form drag, obtained from the comparison with test data of larger out-of-series models. Illustrative results are also given for the influence of the cross-section hull shape, strut configuration, and shifted hulls on the residual resistance and for dynamic trim and draft. Some data are compared with those of the later series tests of twin-hull models with small waterplane area carried out in HSVA, Germany. Factors influencing the residual resistance of ships of this type are discussed.  相似文献   
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