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121.
全球气候变化被认为对波罗的海物理和生态特性有影响.通过全球海气循环模型(AOGCM)的结果统计或动态缩减规模法可以预测未来气候对某一地区的影响.本文用两种不同的波罗的海冰-海耦合模型来模拟现在和未来约100年的冰情.已使用大气气候模型进行了两次以10年为期限的模拟实验,一个实验说明了工业化前的气候状况l检验模拟).另一个是CO2这种温室气体浓度增加150%时的全球气候变暖实验(方案模拟).模型模拟真实地再现了当前气候学冰情和一年里的变化.两个模型模拟的波罗的海每年最大结冰范围是l80~420×10xkm2(检验模拟)和45~270×103km2(方案模拟).检验模拟和方案模拟中每年的最大冰厚分别是32~96cm和11~60cm.对比早期的预测,海冰仍是每年冬天在波的尼亚湾北部和芬兰湾最东部形成总之,两个模型模拟得到的量的变化--像结冰范围和冰厚及其一年里的变化等--相对相似,这是值得注意的.因为这两个冰-海耦合模拟系统是独立研制的.这增加了预测波罗的海未来冰情的可靠性. 相似文献
122.
Markus Salomon 《Environmental Science & Policy》2009,12(3):359-366
The seas and oceans are increasingly a focus of policy interest in Europe. This is mirrored in wide-ranging activities to manage and protect the marine environment, which raises the question of whether such activities go towards developing sustainable management of the seas. Sustainable management calls for an integrated and cross-sectoral approach in order to protect highly valuable marine biodiversity from sea- and land-based activities of all kinds. While some recent developments are fairly promising, there are still no moves on the policy agenda towards uniting all relevant European policy sectors – and particularly the Common Agricultural Policy and the Common Fisheries Policy – under the shared objective of sustainable management and protection of the marine environment and its resources. 相似文献
123.
124.
SUMMARY The emerging concept of industrial ecology (IE) has been applied in practice in few case studies on local/regional industrial recycling networks. Analogously to a natural ecosystem, the aim is to develop material cycles and energy cascades between local cooperative actors. An optimal resource basis of an industrial ecosystem is the sustainable use of local renewable natural resources. In this paper, we consider the region of North Karelia in Finland, with 19 municipalities, and hence somewhat expand the system boundaries of an industrial ecosystem case study. The current situation and two scenarios of municipal heating energy production are presented. The heating system consists of individual, district and electric heating. The heat production and related greenhouse gas emissions are considered. The current fuel use is based on imported oil and regional fuels (peat, wood wastes). Also, shares for co-production of heat and electricity (CHP) are shown. In scenario one, we assume the majority of the fuel basis in oil and absence of CHP. Scenario two illustrates nearly complete dependence on regional wood wastes and firewood with the current share of CHP. The North Karelia region provides the IE theory with a fruitful case study because the supply of waste fuels and local renewables is vast and waste utilisation technologies (CHP, fluidized bed burning) constitute a significant part of energy production. Implications of the applied scenario approach are discussed in the context of regional decision making and, in particular, for its implementation with the concepts of a regional environmental management system (EMS) and a regional industrial ecosystem management system (RIEMS). 相似文献
125.
André Borrmann Angelika Kneidl Gerta Köster Stefan Ruzika Markus Thiemann 《Safety Science》2012,50(8):1695-1703
In this contribution, a combination of a macroscopic and a microscopic model of pedestrian dynamics using a bidirectional coupling technique is presented which allows to obtain better predictions for evacuation times. While the macroscopic model is derived from dynamic network flow theory, the microscopic model is based on a cellular automaton. Output from each model is fed into the other, thus establishing a control cycle. As a result, the gap between the evacuation times computed by both models is narrowed down: The coupled model considers both optimized routing strategies as well as microscopic effects. Accordingly the typical underestimation of evacuation times by purely macroscopic approaches is reduced. At the same time the microscopic model is enhanced by a steering component which reflects the macroscopic knowledge and the impact of supervising personnel on the distribution of pedestrian flows. 相似文献
126.
Non-parametric statistical tests are commonly used in the behavioral sciences. Researchers need to be aware that non-parameteric
methods involving ranks can perform unreliably as a result of very small amounts of noise added in the storage and manipulation
of values by computers, causing spurious reduction in the number of ties. In order to avoid this problem, researchers should
round values to an appropriate number of decimal places prior to the ranking procedure to ensure that data points whose values
cannot be separated according to the precision of their measurement are recorded as having identical rank. We also recommend
exact rather than asymptotic evaluation of p values in non-parametric statistical tests. 相似文献
127.
Realistic meteorological fields are a prerequisite for the determination of pollutant concentrations and depositions by means
of a chemistry transport model. Different configurations of the 5th generation NCAR/Penn State University mesoscale meteorological
model MM5 were tested to determine the optimum set up for long term hindcasts that cover several months up to years. Four
dimensional data assimilation (FDDA) significantly enhances the spatio temporal representation of temperature, humidity and
wind. Best agreement with radiosonde observations could be achieved when temperature, humidity and wind were grid nudged every
6 h. The quality of the resulting meteorological fields showed no significant systematic temporal or spatial variation over
Europe in a model run of the year 2000. It was found that the hydrological cycle was not correctly reproduced by the model
when no nudging was applied. The relevant model run showed too high relative humidity and too high rainfall when compared
to observations. This led to considerably lower aerosol concentrations close to ground and a shift in the deposition patterns
of particle bound pollutants like the carcinogenic benzo(a)pyrene (B(a)P).
Guest Editor: Dr. S. T. Rao. 相似文献
128.
Jenni E Pettay Anna Rotkirch Alexandre Courtiol Markus Jokela Virpi Lummaa 《Behavioral ecology and sociobiology》2014,68(1):135-143
The fitness benefits of multiple mating determine the strength of sexual selection in each sex. This is traditionally quantified by the number of offspring born to once versus multiply mated individuals. In species with (bi)parental care, however, this measure may overestimate the benefits of multiple mating since having several mates can increase offspring number but decrease offspring quality. We analyzed short- and long-term fitness consequences of multiple marriages for both sexes in humans in preindustrial Finnish populations, where monogamy was socially enforced and remarriage was possible only after widowhood. Remarriage increased the lifetime number of offspring sired by men by lengthening their reproductive span but was unrelated to the lifetime number of births for women. However, neither men's nor women's long-term fitness, measured as their number of grandchildren, was significantly increased or decreased by remarriage. These associations were not modified by individual wealth. Our results suggest that despite increasing the number of offspring sired by men, the long-term fitness benefits of serial monogamy may be negligible for both sexes when parental investment is crucial for offspring success and continues to adulthood. They also demonstrate the importance of incorporating long-term fitness measures when quantifying the benefits of mating and reproductive strategies. 相似文献
129.
Scents form the basis for the fragrance industry and various research activities have been developed in different scientific
disciplines all being linked by a common interest in odors and odor perception. In this paper, four different topics have
been selected for a short discussion. Following a short overview on the history of perfumery, the first topic (Natural scents)
is providing some insight into the investigation of natural scents and how this work has strongly stimulated fragrance creation
as well as the quest to find new odoriferous substances for the perfumer’s palette. The second subject (Fragrance chemistry)
gives a historical overview over the chemistry of fragrances and briefly describes the rational behind the synthesis and composition
of new scents. Body odors and their biochemical formation concern the third topic (Body odor biochemistry) which describes
our current understanding of this scientifically interesting field and how knowledge may find use to improve future deodorant
products. The fourth subject (Olfactory mechanisms) deals with the biochemistry in the human nose when odorants are activating
olfactory receptors and enzymes appear to rapidly metabolize the inhaled odorous stimuli. This review does not attempt to
be comprehensive, but it describes selected successes in the fragrance industry and the motivation behind conducting various
types of research. Ultimately, the activities are aiming to bring new ingredients onto the market and improve the quality
of scented products but also to advance our understanding of the power of communication through fragrance. 相似文献
130.
A method involving high resolution gas chromatography combined with ion trap (HRGC-MS/MS) and negative chemical ionisation
(NCI) was developed for the determination of nitrated or oxygenated polycyclic aromatic hydrocarbons (nitro-PAHs, oxy-PAHs)
and other electrophilic substitutes in soil samples. Efficient clean-up was achieved by a combination of methods for the determination
of PAHs in soil and nitro-PAHs in aerosol using solid phase extraction (SPE) and semipreparative high performance liquid chromatography
(HPLC). In samples of surface soil from the city of Basle (Switzerland), nitro-PAHs (mainly 3-nitrofluoranthene and 1-nitropyrene)
were found in concentrations between 30 and 800 ng/kg dry weight. Oxy-PAHs and parent PAHs revealed 102-104-fold higher levels. Nitro-PAHs which are up to 105 times more mutagenic seem to be less persistent in soil than the parent forms, although their entire mutagenic potential
has to be estimated as being on the same order of magnitude. In urban air particulate matter, the amounts of nitro-PAHs (2–62
pg/m3) were 10–100 times lower than oxyPAHs and parent PAHs which were both found in a similar range. 3-nitrobenzanthrone, a recently
described suspected human carcinogen has not yet been detected. Using multivariate statistical analysis, it was possible to
elucidate similarities or special characteristics of substances in a given matrix reflecting their chemical properties or
specific emission sources. 相似文献