中国种子植物特有属的分布区学研究

本文讨论了分布区的概念和分布区周界的划定方法,认为邻近距离平均法(mean propinquitymethod)对划定分布区的周界具有较大的科学性和可用性。根据247幅中国种子植物特有属的分布区图及其属内各种在属分布区范围内的分布情况,我们将中国种子植物特有属划分为5个分布区类型。本文还对中国种子植物特有属分布区与地形和气候条件的关系,以及与植被和植物区系界线的关系进行了分析,提出制约分布区形状和大小的主要决定因素,并指出种在属分布区内的分布规律的研究对次一级植物区系分区或植被区划研究具有重要意义。

Phosphate Distribution and Movement in Soil－Root In－terface Zone：Ⅲ．Dynamics

The depletion rate of phosphate in the soil-root interface zone increased along with growth and phosphateuptake of wheat or maize, which indicated that the phosphate distribution in soil near the root surfaceagreed well with the phosphate movement in rhizosphere and phosphate uptake by plant. The relativeaccumulation zone of phosphate within 0.5 mm apart from the root surface developed at the 15th day or soafter cultivating wheat or maize since the root phosphate secretion increased gradually in this stage. Thephosphate distribution in the soil-root interface zone against the growing time (t) and the distance from theroot plane (x) could be described by the non-linear regression equation with the third powers of x and t.

Research Progress on the Problem of Fluid,Heat and Energy Distribution near the Earthquake Source Area

As the basic problems in seismology, fluid, heat and energy distribution near earthquake sources during earthquake generation have been the leading subjects of concern to seismologists. Currently, more and more research shows fluid around earthquake source areas, which plays an important role in the process of earthquake preparation and generation. However, there is considerable controversy over the source of fluid in the deep crust. As for the problem of heat around earthquake source areas, different models have been proposed to explain the stress heat flow paradox. Among them, the dynamic weakening model has been thought to be the key to solving the heat flow paradox issue. After large earthquakes, energy distribution is directly related to friction heat. It is of timely and important practical significance to immediately implement deep drilling in-site surveying to gain understanding of fluid, friction heat and energy distribution during earthquake generation. The latest international progress in fluid, heat and energy distribution research has been reviewed in this paper which will bring important inspiration for the understanding of earthquake preparation and occurrence.

Oil shale resources in China and their utilization

The unconventional oil and gas resources presented in oil shales have meant these potential sources of hydrocarbons, which has become a research focus. China contains abundant oil shale resources, ranking fourth in the world, with ca. 7 254.48 x 108 t within 24 provinces, including 48 basins and 81 oil shale deposits. A- bout 48% of the total oil shale resources are concentrated in the eastern resource region, with a further 22% in the central resource region. 65 % of the total quantity of oil shale resources is present at depths of 0-500 m, with 17% of the total resources being defined as high-quality oil shales yielding more than 10% oil by weight. Chinese oil shale resources are generally hosted by Mesozoic sediments that account for 78% of the total re- sources. In terms of the geographical distribution of these resources, some 45% are located in plain regions, and different oil shale basins have various characteristics. The oil shale resources in China represent a highly prospective future source of hydrocarbons. These resources having potential use not only in power generation and oil refining but also in agriculture, metal and chemical productions, and environmental protection.

Distribution of heavy metals in the topsoil of the Jining mining area

The geochemical baseline is the fundamental reference for environmental change and assessment.In this article we describe cluster and regression analyses with a normalization procedure.The elements Sc and Ag were chosen to calculate the environmental geochemical baseline.The geoaccumulation index was calculated and mapped to indicate the environmental quality of the soil.The results show that the urban areas are barely polluted with Ni and Cr but the rural areas in the southern part of the city, and the western part of the lake,are polluted with Ni,Cr,and Cu at the second level.On the other hand,the rural areas in the southern part of the city,and the western part of the lake,are polluted with As at a moderate level.The other area is polluted at the second level.An increase in As pollution occurs in a direction from northeast to southwest.The Cd pollution follows a trend similar to As,with an additional smaller contaminated area polluted at levelⅢ.The Hg pollution typical of urban areas occurs in the main and northern parts of the city.The geochemical accumulation index decreases from the city center to the periphery.The highest pollution level reaches levelⅣ,which indicates that the soil is seriously polluted with Hg.The southern part of the city and the rural areas to the west of the lake are not contaminated with Hg.Geological factors and the disturbance from human activities are both possible major factors:further research is needed to identify them.

Application of Tracer Model in the Remaining Oil Distribution of 95 Block Oilfields of Central Plains

With the development and utilization of oil and gas fields, oil mining become more and more difficult. The remaining re- serves of oil in the oil distribution is difficult to confirm, in order to understand and grasp the distribution of the remaining oil in the reser-voir, calculated using tracer concentration methods used mathematical models to calculate the residual oil saturation in the reservoir, from the theoretical analysis of tracer migration process, you can more accurately determine the distribution of the remaining oil, this method has good prospects for development.