保护地球

暑假里的一天，我和爸爸、妈妈乘车去爷爷家。我们来到车站，只见人山人海，拥挤不堪。

Geoscience landscape division and tourism zonation in the mid-southern section of the Hengduan Mountains, eastern Qinghai-Tibet Plateau

The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape classification system is an important scientific basis for landscape protection and tourism development in this region. By combining geology and geography and referring to the concepts of "system tract" and "tectonic system" in geology, this paper comes up with grading standards for the geoscience landscape system of this region. Based on the regional stratigraphic structure, tectonic fault marks and geomorphological differentiation, this paper comes up with 2 Grade Ⅰ geoscience landscape system tracts, 8 Grade Ⅱ geoscience landscape systems, 21 Grade Ⅲ geoscience landscape areas, and 165 representative Grade Ⅳ geoscience landscape attractions. According to the main classification methods for the geological heritage and tourism landscapes, the geoscience landscapes can be divided into 4 categories, 16 types and 19 subtypes. On this basis, 23 eco-tourism areas of the mid-southern section of the Hengduan Mountains can be delimited. The study provides a theoretical direction and method reference for the geoscience landscape division and tourism zonation, which has an importantsignificance on the mountain landscape protection and tourism development in the regions of complex geo-environments.

Comparison between open phase fault of arc suppression coil and single phase to earth fault in coal mine distribution network

When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and reliable run of the network. We first introduce a three-phase five-column arc suppression coil (TPFCASC) and discuss its autotracking compensation theory. Then we compare the single phase to ground fault of the coal mine distribution network with an open phase fault at the TPFCASC using the Thévenin theory, the symmetrical-component method and the complex sequence network respectively. The results show that, in both types of faults, zero-sequence voltage of the network will appear and the maximum magnitude of this zero-sequence voltage is different in both faults. Based on this situation, a protection for the open phase fault at the TPFCASC should be estab-lished.

The Effect of Anthropogenic Increase on the Earth as a Life-Support System for Mankind

Exponential increase of anthropogenic impact （human population number, some technological parameters） becomes menacing for biosphere functioning. Anyway, we should be able to estimate quantitatively limits of our impact on functional parameters of the biosphere. Considering biosphere as a natural life-support system （LSS）, we can receive the helpful information for working out and creation of artificial LSS of various types. Big biotic cycle induced with flows of a solar energy, is a basis of functioning of the biosphere and its basic cells-ecosystems. It＇s possible to summarize briefly the main functional and structural properties of the biosphere： integrity, closure, substance cycling, steady state, energy dependence and biodiversity. These properties of the biosphere, as a LSS, ensure potentially everlasting life under the conditions of a limited quantity of substrate suitable for the life on the planet. Ecological Footprint （EF） as a quantitative measure of anthropogenic impact on biosphere functioning is discussed in the paper. The index of the ecological reliability （IER） is introduced as a quantitative ecological indicator of different territories. The comparative dynamics of the United Nations＇ Human Development Index （HDI） and EF is discussed. The vital goal of sustainable human development： all humans can have opportunity to fulfill their lives without degrading the biosphere. To support sustainability, we should try to develop each nation and the mankind as a whole with a high HDI and a low ecological footprint. It means to have high level of HDI at low level of EF. But current tendency of economical and social development shows that the higher HDI is, the bigger EF is. EF of mankind is growing menacingly. Now actual pressure of the human civilization of our planet （2010） upon 50% exceeds its potential possibilities biological capacity （BC）, measured on the area ＂global＂ green hectares）. It means that we need 1.5 planets of the Earth＇s type. It leads to ecological incident in the scale of biosphere. Our biosphere is the large, multilevel, hierarchically organized system, and our civilization is only a part of it. This part is not central; it can disappear for ever, if we do not cope to be included in the biosphere as a great system.

Phosphorus Biogeochemical Cycle Research in Mountainous Ecosystems

Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus becomes a crucial process which needs to be fully understood and described for ecological and environmental conservation.However,most of research about P biogeochemical processes has been carried out in aquatic environment and agronomic field,but rare researches have been done in mountain ecosystem.In the present review,we summarize researches on P biogeochemical cycle concerning mountain ecosystem in recent decades,including rock weathering,the release,transformation and bioavailability of P,interactions between the P biological cycle and microbial and plant life,as well as the development of models.Based on the state of art,we propose the future work on this direction,including the integration of all these research,the development of a practical model to understand the P biogeochemical cycle and its bioavailability,and to provide a reference for ecological and environmental conservation of mountainous ecosystems and lowland aquatic systems.

Develop hydroenergy resources and protect earth environment

Energy is a driving force behind the progress of human civilization. Mainly depend on the current human society of non-renewable fossil energy sources, such as coal and oil, its increasing demand. Gradually reduce the reserves, the contradiction between supply and demand becoming increasingly prominent. With the process of human history has moved forward with the depletion of fossil energy will eventually be unable to sustainable use. The total hydropower resources are limited, but it is renewable, clean energy, its energy is infinite. Therefore, the full use of limited water resources and slow down the depletion of fossil energy process, is to improve and protect the earth’s ecology and environment, one of the most realistic measures.

Thermodynamic analysis of a space station remote manipulator with a harmonic drive that considers an integrated thermal protection layer.

To eliminate anomalies and improve the performance of a space station remote manipulator(SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an integrated thermal protection system(ITPS). Solar radiative heat gain and loss become equally significant as conductive heat transfers through the interior of the SSRM on orbit. A thermodynamic model of the SSRM with a sandwich ITPS structure is established on the coupling between harmonic drive and changeable thermal environment. A motion precision is proposed to evaluate thermodynamic behavior under continuously changeable thermal circumstances. Simulation results indicate that the ITPS with a corrugated sandwich structure reduces the maximum amplitude of angular position errors to 41.6%, which helps improve the motion precision of the SSRM. The feasible regions for the SSRM in the Low Earth Orbit(LEO) and Geostationary Earth Orbit(GEO) are analyzed, which shows that the proportion of feasible region in LEO is significantly larger than that in GEO.