Papers by Keyword: Sink

Abstract: A submarine must conform to Archimedes’ Principle, which states that a body immersed in a fluid has an upward force on it (buoyancy) equal to the weight of the displaced fluid, (displacement). Submarines are ships capable of being submerged. The history of submarines and their operation have largely revolved around being able to alter the density of the vessel so that it may dive below the surface, maintain a depth, and return to the surface as needed. The way modern submarines accomplish this task is to bring in and remove water from tanks in the submarine called ballast tanks. Ballast tanks fit into two categories: those used for major adjustment of mass (main ballast tanks); and those used for minor adjustments (trim tanks). The effect of each tank is plotted and this is compared with the changes in mass and trimming moment possible during operations using a trim polygon to determine whether the ballast tanks are adequate. On the water surface, metacentric height (GM) is important, whereas below the surface it is the distance between the centre of buoyancy and the centre of gravity (BG) which governs the transverse stability of a submarine.

Abstract: Global warming is one of the key fields of global change ecology．The sources and sinks of the Greenhouse Gases (GHGes) in the atmosphere：which result in climate warming have been widely investigated around the world in the last 1 0 years．In this paper, sources and sinks of main GHGes in the atmosphere(CO2，CH4，N20)were reviewed．It is believed that the emission／uptake flux of the 3 GHGes between the atmosphere and various ecosystems were not precisely quauntified yet and there are some uncertainties with aspect to the：kind of source and sink．By analyzing related literature, the trends of international：research on the source and sink of the main GHGes were summarized as follows：more and more advanced instruments have been used in the research，more an d more regions have been investigated，more and more concerns have been on the response of emission／uptake flux of the 3 GHGes to the global change an d integrated research comprising ecology ,soil biology, meteorology, microbiology, atmospheric physics，etc．In our country, the research on source and sink of the 3 GHGes were developed since 1 980s．Compared with advanced countries，our related researches were conducted in fewer sites with less frequency and were less systematic． the rapid development so far involved CH4 emission from rice paddies, wetlands, CH4 and N2O emissions from the study of loess - paleosol sequence composition characteristics of greenhouse gases, and forest, agriculture, Soil CO2 emission and absorption of research in the field.

Abstract: In order to provide background information and scientific basis for pollution control of Pb, this paper analyzed the sink and transfer process of Pb in Jiaozhou Bay. Results showed that Pb in Jiaozhou Bay was mainly sourced from agricultural non-point source and urban point source, as well as atmosphere dry and wet deposition, leading to the contents of Pb were increasing from spring to summer, and decreasing in autumn and winter. Due to Jiaozhou Bay is a closed bay, the narrow bay mouth is vital to the water exchange, which is the force of horizontal distributions. Horizontal diffusion and vertical deposition were the two major transferred processes of Pb, leading to a large amount of Pb was finally transferred to the sea bottom of the bay mouth areas, and the sea bottom of bay mouth areas was the sink of Pb in Jiaozhou Bay.

Abstract: Dissemination is a data dissemination protocol for wireless sensor network based on TinyOS. The purpose of it is that we can send data to every node reliably Dissemination can reconfigure,query and reprogram nodes easily This article briefs the mechanism of Dissemination,and analyzes its principle. At last, it is applied in practice. Practice shows that, when network traffic is small, Dissemination has good performance, and reliable, simple to deploy, with high practicability and value. But when network is large, its performance is poor. So, based on the specific practice, Dissemination is improved.

Abstract: In the wireless sensor network routing protocol design, the sensor node monitoring data in multi-hop relay approach to sink node for transmission. For sink aggregation node fixed network, the nearby sink nodes of sensor nodes need to transfer other nodes of the monitoring data, consequently, it consumes large amounts of energy, and it's easy to premature death, making the network connectivity decline, even making the network intersected, shorten the lifetime of the network. In order to solve this problem, from the view of sink node, this thesis brings forward a protocol of SERP, which is a energy balancing routing protocol based on sink Mobility and prolongs the lifetime of network. It adopts the strategy of sink movement which makes the hot nodes inside the network take turns, balances the load among them. In SERP, firstly, the WSN deployment area is divided into finite Virtual cells ;Secondly ,we make the center of each virtual cell as the mobile position of sink node; at last, we confirm the residence time when sink node stays in each position through linear programming. Finally, the paper makes simulation al analysis aiming at above-mentioned routing protocols . The result shows that the inside node energy consumption is comparatively balanced and efficient, and the network lifetime is prolonged effectively.

Abstract: Green architecture, a termed entitled to the architectures which dedicate great importance to the environment, is one of the characteristics of the sustainable design in which environmental sustainability is more important [1]. In the modern notion of architecture and programming, rain water is usually treated as “castoff”, or as eternal energy splurged by us. Some irrational design produces a lot of unsinkable ditches and culverts crossed underground, which leads to drainage and wastage of the water in the earth. Extensive artificial lawn accelerates the water evaporation of the earth. Large amount of unsinkable reinforced tough paving layer in cities disturbs the ecological balance of the earth, etc.. All these above give more grave non-ecological factors to the concrete jungle. When talking about the recycle and reuse of water in city, we should thinking about promoting the life system balance in ecosphere, which is the theme of this thesis. This thesis tries to give a systematic and in-depth discussion on architectural water recycle design by collecting materials, to give an ecological recycle design of preserving, saving and purifying water on the aspect of architecture and environment. Through the analysis on infiltration, storage and reuse of rain water in cities of different countries and regions, this thesis tries to expatiate the contribution of rain water collection and evaporation to the urban ecology, and proposes ecological way of water use considering regional climate to achieve the aim of eternal water use in urban ecological system.

Abstract: From a mathematical model of one kind complicated financial system, we make a dynamic analysis on this kind of system on the basis of studies of scholars both at home and abroad. We find characteristics of various dynamic systems driven by different parameters, and study possible Hopf bifurcation as well as the relationship between Hopf bifurcation and the values of parameters. Besides, we make use of algorithm to analyze complexity of the system. The results of numerical simulation prove that the theory used in the thesis is correct. This study is regarded with good theoretical and practical value.