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Organic carbon budget for the Gulf of Bothnia   总被引:1,自引:0,他引:1  
We calculated input of organic carbon to the unproductive, brackish water basin of the Gulf of Bothnia from rivers, point sources and the atmosphere. We also calculated the net exchange of organic carbon between the Gulf of Bothnia and the adjacent marine system, the Baltic Proper. We compared the input with sinks for organic carbon; permanent incorporation in sediments and mineralization and subsequent evasion of CO2 to the atmosphere. The major fluxes were riverine input (1500 Gg C year− 1), exchange with the Baltic Proper (depending on which of several possible DOC concentration differences between the basins that was used in the calculation, the flux varied between an outflow of 466 and an input of 950 Gg C year 1), sediment burial (1100 Gg C year− 1) and evasion to the atmosphere (3610 Gg C year− 1). The largest single net flux was the emission of CO2 to the atmosphere, mainly caused by bacterial mineralization of organic carbon. Input and output did not match in our budget which we ascribe uncertainties in the calculation of the exchange of organic carbon between the Gulf of Bothnia and the Baltic Proper, and the fact that CO2 emission, which in our calculation represented 1 year (2002) may have been overestimated in comparison with long-term means. We conclude that net heterotrophy of the Gulf of Bothnia was due to input of organic carbon from both the catchment and from the Baltic Proper and that the future degree of net heterotrophy will be sensible to both catchment export of organic carbon and to the ongoing eutrophication of the Baltic Proper.  相似文献   
2.
This paper describes an approach to the development of metropolitan transport strategies based on community needs and values. A search conference and other consultation methods were used to raise community awareness of transport issues and to give the transport planners an understanding of community concerns and values. The collective values were used to develop a vision statement of where Melbourne could be in the future. Transport strategies were then developed which helped achieve the vision. By this approach transport strategies can be integrated with the delivery of other services so that they are complementary and achieve consistent ends. The process encouraged community debate and helped strategy development to focus on what was to be achieved, rather than on particular techniques or interest group agendas. Integrated strategies which have wide interest group and community support can be developed by the process.  相似文献   
3.
目前在欧洲,汽车制造商们已经把大量的汽车诊断维修资料存储在了计算机里,但是,除这些非汽车制造商们心血来潮,突发出一个大慈大悲的“全心全意”为人民服务的念头,否则的话,汽车维修行业的同仁们就别指望能够接触到多少这类必须的技术资料。这些技术资料对于形成一个汽车维修企业的市场竞争力显然是至关重要的。本文仔细分析了欧洲的八个著名的汽车品牌在这方面的所作所为,并同时会让大家了解到,要想在汽车诊断维修行业激烈的竞争中立于不败之地的话,你还需要借助什么样的“法宝”来武装自己。  相似文献   
4.
A MacPherson front wheel suspension and its components are modelled with the finite element method. Nonlinearities due to both the geometry and the characteristics of the components (springs, dampers and bushings) are considered. The force due to a given compression/elongation of the spring strut is calculated and compared with experimental results. Kinematical results, change in track width and camber angle, are also shown and compared with experimental results. Good agreement between numerical and experimental results is obtained.  相似文献   
5.
Abstract

Indirect effects are important considerations when making consequence analyses in general and in strategic environmental assessments in particular of potential transport solutions and infrastructure plans. The primary objective of this paper is to emphasize the need for a deeper understanding of the long‐term system effects of investments in transport infrastructure with a focus on the structuring effects that roads and railways have on society, e.g. altered transport patterns, altered settlement structures and changes in use of the built environment. Special attention is given to the following potential indirect effects: increased total transport volume, increased share of private motorists and truck transport, increased urban sprawl, and increased energy use in buildings. The conditions that determine the power of the effects are discussed and a number of key factors to be considered in transport infrastructure planning, especially in strategic environmental assessments, are suggested. Since many indirect effects emerge over time, an extended time perspective is of essence. Therefore, scenario techniques may be useful when analysing indirect effects in transport planning processes.  相似文献   
6.
The objective of this study was to study whiplash injury outcome in front-seat occupants in rear-end impacts using double paired comparison technique. The combination of gender, seated position, and outcome was analyzed. Folksam, a Swedish insurance company, has a database of whiplash injuries. A questionnaire was used to collect study data. The response rate was 81%. The inclusion criteria included medical impairment one year after the impact, as judged by medical specialists. The study included rear-end impacts between 1990 and 1999 that resulted in at least one permanent neck injury impairment; in total, 430 impacts with 860 occupants and 444 impairments. Of those suffering impairment, 302 were female and 142 male; 235 were seated in the driver's seat and 209 in the front passenger seat. Relative risk estimates for impairing whiplash injury, by gender and seated position:
1.
Driver male (DM)/passenger female (PF) relative risk = 0.5 n = 218  相似文献   
7.
Integrating natural and socio-economic science in coastal management   总被引:2,自引:0,他引:2  
The future more sustainable management of coastal resources is an important policy goal for all governments of countries with coastlines. Coastal areas are under intense environmental change pressure with extensive feedback effects between the natural systems and the human systems. It could be argued that there is just one jointly determined and coevolving system that needs to be studied and managed. Understanding the interactions between the coastal zone and environmental change cannot be achieved by observational studies alone. Modelling of key environmental and socio-economic processes is a vital tool, required to buttress coastal management institutions and practice. Three overlapping procedural stages can be identified in the coastal resource assessment process. The scoping and auditing stage, implemented via a ‘pressure–state–impact–response’ framework, details, among other thing, problems, system boundaries and value conflicts. The framework is itself based on a conceptual model, which lays stress on functional value diversity and the links between ecosystem processes, functions and outputs of goods and services which are deemed ‘valuable’ by society. The two subsequent stages are integrated modelling, combining natural and social science methodologies, and evaluation of management options and related gains and losses. An overview of a research project, which utilised the pressure–state–impacts–response (P–S–I–R) framework and supporting concepts and methods, is presented in the last section of the paper, together with some generic ‘lessons’ for interdisciplinary research.  相似文献   
8.
亚洲汽车厂商生产的车辆一直很受美国消费者欢迎,亚洲品牌汽车经常名列最佳制造车辆的排行榜中.但即使质量再好,也难免有出故障的时候,维修任务就自然落到维修工身上了.……  相似文献   
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