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91.
This study demonstrates the usefulness of cellular energy allocation (CEA) evaluations as a physiological biomarker to infer the occurrence of natural stress in native populations of mussels inhabiting the stratified estuary (Krka River estuary, Croatia). Sampling sites were selected based on their differences in the salinity and temperature. The CEA value was calculated as a ratio between available energy (Ea) and energy consumption (Ec). Generally, higher values of Ea were recorded in June than in November, which were especially evident in the storage components (carbohydrates and lipids), while the constitutive component (proteins) remained relatively constant. The highest Ec was recorded in mussels at estuarine site compared to coastal site, which may be caused by the energetically costly maintenance of osmotic balance. Decrease in CEA recorded in estuarine mussels may ultimately result in a lower amount of energy available for growth, reproduction, or defence against other stresses (e.g. pollution). 相似文献
92.
Rhodococcus sp. P14 was isolated from crude oil-contaminated sediments. This strain was capable of utilizing three to five rings polycyclic aromatic hydrocarbons (PAHs) including phenanthrene (Phe), pyrene (Pyr), and benzo[a]pyrene (BaP) as a sole carbon and energy source. After cultivated with 50mg/L of each PAH, strain P14 removed 43% Phe, 34% Pyr and 30% BaP in 30 d. Four different hydroxyphenanthrene products derived from Phe by strain P14 (1,2,3,4-hydroxyphenanthrene) were detected using SPME-GC-MS. Strain P14 also was capable of degrading mineral oil with n-alkanes of C17 to C21 carbon chain length. Compared with glucose-grown cells, PAHs-grown cells had decreased contents of shorter-chain length fatty acids (≤ C16:0), increased contents of C18:0, Me-C19:0 and disappeared odd-number carbon chain fatty acids. The contents of unsaturated C19:1, Me-C19:0 increased and C18:0 decreased in mineral oil-grown cells. At the same time, the strain P14 tended to float when cultivated in mineral oil-supplemented liquid medium. The degradation capability of P14 to alkane and PAHs and its floating characteristics will be very helpful for future's application in oil-spill bioremediation. 相似文献
93.
地震强度分布不均匀性的摩擦时间依从CA模型 总被引:2,自引:1,他引:2
设计一个摩擦时间依从的地震活动性细胞自动机模型(CA),研究产生地震累积频度-震级关系曲线中,出现拐点的地震强度分布不均匀现象的物理原因。外界通过应力加载向模型输入能量,模型的细胞之间存在非线性的相互作用。对比分析规定单个细胞破裂与模型地震之间不同的决定规则时产生的地震序列的累积频度-震级关系,研究结果表明,地震的级联破裂方式是引起累积频度-震级关系在震级较低范围和震级较高范围之间不连续的因素之一。 相似文献
94.
用算法复杂性分析时间序列 总被引:11,自引:1,他引:11
本文介绍了算法复杂性的概念,总结了算法复杂性的一些性质,对其所具有的优点及在计算中所存在的问题进行了讨论。通过用算法复杂性C(n)分析由地震细胞自动机模型产生的地震时间序列,说明算法复杂性用于研究地震活动演化及地震活动图象是有希望的。 相似文献
95.
城市空间扩张是复杂的社会经济进程,伴随着人口、政策和城市要素向外推进等现象,是评判城市化水平的重要指标。元胞自动机(Cellular Automata,CA)是可以模拟事物发展演化过程的系统动力学模型,可以有效揭示城市空间扩张过程的特征和机制,具有广阔的应用前景。根据Geo-CA的内涵与特征,以湖南省衡阳市为例,考虑城市空间扩张的主要影响因素,本文提出了多因素制约的城市空间扩张过程元胞自动机模拟模型(Multi-factors Constrained Expanding Simulation CA,MCESCA)。结合多期LANDSET影像、DEM和规划数据等数据源,论文构建并实现了MCES-CA模型,取得了较好的模拟结果。经检验,MCES-CA的模拟精度总体达89.24%。模拟结果显示衡阳主城区的空间扩张具有多方向、多阶段的特征,受到城市的自然环境和发展规划等因素的制约。本文研究表明,MCES-CA是一种简洁、易实现且高效的城市空间扩张模拟工具,今后应该结合人工智能方法提高模拟结果的精度。 相似文献
96.
Experiences and issues of using cellular automata for assisting urban and regional planning in China 总被引:1,自引:0,他引:1
Xia Li Yimin Chen Xiaoping Liu Xiaocong Xu Guangliang Chen 《International journal of geographical information science》2017,31(8):1606-1629
Since the late 1990s, there are growing studies on the development of cellular automata (CA) as a simulation tool for assisting urban and regional planning in China. Rapid urban development is the main reason that this country has become one of the best places to test the methodology of CA and analyze the effectiveness of using these models. This paper attempts to summarize the experiences and issues of using CA to solve various environmental and planning problems in China. The analysis is based on the literature review using the search engines of ISI Web of Science and Google Scholar. These experiences could be important for those who want to apply CA in developing countries. For example, which environmental and ecological problems can be solved by using this bottom-up approach? What are the data inputs to these models and how can they be calibrated? Our analyses indicate that CA have the great potential to support land-use planning and policy analysis for fast-growing regions. Some specific features of using CA in China are also identified in the literature review, including delineation of urban growth boundary, prevention of illegal development and formulating zoning schemes. The CA studies in this fast-growing country provided valuable experiences for other developing countries to solve a series of simulation and planning problems by using this bottom-up approach. 相似文献
97.
土地利用变化模拟模型及应用研究进展 总被引:9,自引:0,他引:9
元胞自动机CA(Cellular Automata)和多智能体ABM(Agent-Based Model)模型是土地利用格局和演化模拟的主流方法,两者在模拟自然因素影响和人文驱动机制方面具有突出优势,为LUCC研究提供了重要的工具。当前,ABM无论在模型构建还是应用研究方面,CA和ABM均取得了显著进展。论文从数据基础、模拟尺度、CA转换规则挖掘、ABM行为规则定义、CA和ABM的耦合4个方面梳理土地利用模拟模型和方法的研究进展。并总结这些模型在虚拟城市模拟与理论验证、真实城市模拟与规划预测以及多类用地模拟与辅助决策等方面的应用。最后,总结土地利用模拟模型在精细模拟和全球变化研究方面存在的局限性,认为未来发展将主要集中于解决从2维模型向3维模型发展、大数据与规则精细挖掘以及大尺度模拟与知识迁移等问题。 相似文献
98.
Oksana Sytar Marian Brestic Abhay Kumar M. N. V. Prasad Nataliya Taran Iryna Smetanska 《洁净——土壤、空气、水》2013,41(11):1129-1137
In this study, Fagopyrum esculentum (common buckwheat) sprayed with nickel (Ni) (0, 0.5, 1.0, 3.0, and 5.0 mM) for different duration has been investigated for Ni accumulation, malondialdehyde (MDA), total phenolics, and phenolic acids. Ni accumulation significantly increased in dose‐dependent manner. Plants exposed for 72 h, showed visible damages as chlorosis and irreversible necrosis. The MDA and total phenolic contents increased at 24 h of Ni treatments. HPLC data revealed that phenolic acids are in good correlation with concentration and durations of treatments. After 24 and 48 h the contents of chlorogenic, p‐hydroxybenzoic, hesperetic, p‐anisic, and caffeic acids increased in Ni treated leaves. On the other hand, p‐hydroxybenzoic, hesperetic, p‐anisic, p‐coumaric, caffeic acids contents decreased after 72 h of Ni exposure. Vanillic and cinnamic acid followed same pattern and increased significantly at 3.0 and 5.0 mM after 48 h of Ni exposure. It may suggest that buckwheat can be possible hyperaccumulators of Ni, because of high Ni accumulation in tissues through foliar treatment. Furthermore, the analyzed phenolic acids have potential role as antioxidants, which provide tolerance to buckwheat against Ni treatment. 相似文献
99.
Gil R. Pontius Corresponding author Jeffrey Malanson Corresponding author 《International journal of geographical information science》2013,27(2):243-265
This paper compares two land change models in terms of appropriateness for various applications and predictive power. Cellular Automata Markov (CA_Markov) and Geomod are the two models, which have similar options to allow for specification of the predicted quantity and location of land categories. The most important structural difference is that CA_Markov has the ability to predict any transition among any number of categories, while Geomod predicts only a one‐way transition from one category to one alternative category. To assess the predictive power, each model is run several times to predict land change in central Massachusetts, USA. The models are calibrated with information from 1971 to 1985, and then the models predict the change from 1985 to 1999. The method to measure the predictive power: 1) separates the calibration process from the validation process, 2) assesses the accuracy at multiple resolutions, and 3) compares the predictive model vis‐à‐vis a null model that predicts pure persistence. Among 24 model runs, the predictive models are more accurate than the null model at resolutions coarser than two kilometres, but not at resolutions finer than one kilometre. The choice of the options account for more variation in accuracy of runs than the choice of the model per se. The most accurate model runs are those that did not use spatial contiguity explicitly. For this particular study area, the added complexity of CA_Markov is of no benefit. 相似文献
100.