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41.
国际科学界跨世纪的重大研究主题——国际全球变化研究实施十年进展与现状 总被引:2,自引:0,他引:2
全球变化研究是国际科学界跨世纪的重大研究主题。国际全球变化研究从其组织、计划制定与实施已逐渐形成了一套有机的完整的框架体系,整体推动着全球变化研究的深入开展。文章从国际全球变化的组织框架、计划体系和主要研究环节等主要方面概述了国际全球变化研究实施十年后的进展与现状,特别是分析概括了全球变化研究的主要环节——观测研究、过程研究、预测研究、数据与信息管理研究、影响(后果)分析研究、对策研究与政策评估研究,简明概述了其研究现状与进展 相似文献
42.
用AutoLisp编程给点的z坐标赋高程值 总被引:1,自引:0,他引:1
李向东 《测绘与空间地理信息》2008,31(1):173-174
在土方量的计算中,需要提取点的3维坐标。而许多电子版地形图的z坐标值均为0,此时就需要对关联点的z坐标赋高程注记值。本文介绍用AutoLisp进行简单的编程、实现赋值的过程。 相似文献
43.
在土方量的计算中,需要提取点的3维坐标。而许多电子版地形图的z坐标值均为0,此时就需要对关联点的z坐标赋高程注记值。本文介绍用AutoLisp进行简单的编程、实现赋值的过程。 相似文献
44.
This paper sets out the motivation for carrying out an observational experiment on the atmospheric boundary layer along the
monsoon trough, in the light of earlier studies of the atmospheric boundary layer in India and elsewhere, and the significant
role that the trough has been shown to play as a key semi-permanent feature of the southwest monsoon. The scientific objectives
of the experiment are set out, and its planning and execution are touched upon. Some of the gains resulting from the experiment
are mentioned, and lessons for the future about the conduct of such programmes are drawn. 相似文献
45.
46.
Young stakeholders are key actors in social-ecological systems, who have the capacity to be agents of sustainability transformation but are also at high risk of exclusion in the unfolding of global change challenges. Despite the focus of sustainability on future generations, there has been little research effort aimed at understanding young actors’ roles as biosphere stewards. In this work we investigate how young stakeholders perceive and participate in the implementation of sustainability objectives in 74 Biosphere Reserves of the United Nations Educational, Scientific and Cultural Organization’s (UNESCO) the Man and the Biosphere (MAB) Programme across 83 countries, through participatory group workshops, individual surveys and grey literature review. We explore to what extent youth perceptions are aligned or not with current understandings of Biosphere Reserves and how young stakeholders are acting in pursuit of Biosphere Reserve objectives. We find that young stakeholders have a comprehensive understanding of the opportunities and challenges faced by environmental governance, such as resilience and adaptation to global change and the governance challenges of implementing adaptive co-management and increasing stakeholder participation. We also show that young stakeholders can be active participants in a wide range of activities that contribute to achieving conservation and development goals in their territories. They are particularly concerned with youth participation within all levels of Biosphere Reserve functioning and with the creation of sustainable livelihood opportunities that will allow future generations to remain in their native territories. Our study provides evidence of the importance of young stakeholder knowledge and perspectives as central actors in conservation and development initiatives, like Biosphere Reserves, and of the need to increase young stakeholder integration and participation within environmental governance. 相似文献
47.
In the territory of Altomonte, a village located in Calabria, in the Southern part of Italy, a new thermoelectrical station
is under construction. This work involved major earthworks which regarded new excavated slopes. In order to protect soil from
erosion due to rainfall and runoff and also in order to prevent superficial soil instability, it was decided to plant four
different species of perennial “gramineae” plants (Eragrass, Elygrass, Pangrass and Vetiver) characterised by deep roots.
Works began in November 2002 and ended in May 2003, a period marked by very different climate and meteorological conditions,
varying from exceptionally rainy and cold winter to warm and dry spring months. The paper describes the different stages of
the project and the monitoring programme for the following months. The extension of the work and the use of four different
kinds of vegetation made periodic inspections of the entire site appropriate. Two in situ investigations, respectively performed
in August 2003 and in November 2003, are outlined. The aim of these surveys was to confirm the success of the work by verifying
the growth of the plants and roots. The principal monitored parameters were the percentage of sprouted plants, the height
of the foliage and the depth of roots. The investigations showed good results, keeping in mind the very difficult climatic
conditions and the extreme poor fertility of the topsoil laid down upon the clay layer: in particular, high survival rate
were measured over the entire area of the works and the root systems have developed sufficiently to grow through the upper
topsoil layer (0.2–0.3 m) into the underlying clay layer. In March 2004, a sampling programme was undertaken on the same site.
Direct shear tests were carried out in the laboratory in order to evaluate the increase in shear strength of the rooted soil
mass. The research involved the recovery of three undisturbed samples of soil with roots for each of the four types of “gramineae”
plants and three undisturbed samples constituted only of soil, from the surface to a depth of 1.0 m. The tests were performed
in a large direct shear apparatus on 200 mm diameter samples. The test results allowed to evaluate the roots’ contribution
of the different gramineous species and to underline the direct correlation between the increase in soil shear strength and
the root tensile strengths. In particular, an increase in cohesion ranging between 2 kPa and 15 kPa was recorded, according
to the different species: the maximum values of increase in shear strength were reached by Vetiver roots, which are also characterised
by the highest tensile strength. 相似文献
48.
简述了石化工业区震害特点,并简要分析了该工业区可能发生的震害,根据石化工业区抗震规划的特殊性,给出了石化工业区抗震减灾规划的内容和其自身的抗震规划模式,并提出了今后在该工业区进行抗震规划工作需要进一步研究的问题。 相似文献
49.
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