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一种有效的海湾氮、磷非保守物质物理-生物耦合模型
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作者 张喆 《环境保护》 CAS CSSCI 北大核心 2009年第4期72-74,共3页
海湾赤潮现象频发,氮、磷等非保守污染物质的数值模拟研究成为国内外研究的热点。本文通过引进一种适用的物理-生物耦合模型,并运用该耦合模型进行氮、磷等非保守物质的数值模拟研究是可行的,最终表明,该耦合模型具有广阔的发展前景。
关键词 非保守物质 海湾 物理-生物耦合模型 数值模拟
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桑沟湾水动力特征及其对养殖容量影响的研究——观测与模型 被引量:15
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作者 魏皓 赵亮 +7 位作者 原野 史洁 樊星 刘志宇 王鲁宁 袁承仪 王玉衡 魏莱 《渔业科学进展》 CSCD 北大核心 2010年第4期65-71,共7页
主要介绍了从动力学研究桑沟湾养殖容量的主要思路、方法及结果。研究以精细过程观测为基础,以数值模型为手段,从物理海洋学角度考察养殖海区水动力特征,研究水动力对物质循环的影响、对颗粒态/溶解态营养物质的补充和对养殖生物量的影... 主要介绍了从动力学研究桑沟湾养殖容量的主要思路、方法及结果。研究以精细过程观测为基础,以数值模型为手段,从物理海洋学角度考察养殖海区水动力特征,研究水动力对物质循环的影响、对颗粒态/溶解态营养物质的补充和对养殖生物量的影响,探寻不同养殖模式效果的技术路线;介绍了两个航次设计方案与目的。通过观测发现养殖对水动力垂直结构有很大影响,底层流速最大并滞后表层,发现弱动力条件下海底颗粒物和营养盐无法进入水体上层的事实。据此提出双边界层动力模型,建立一维数值模型进行机制探讨,将养殖阻力三维化建立水动力数值模型,定量给出养殖对水动力和水交换的阻碍;以此驱动三维养殖生态模型,充分考虑养殖对水动力的影响、水动力对生源要素的输运。建立了一个真正的物理-生物过程耦合模型。利用该模型进行的数值模拟和实验表明,贝藻兼养多元养殖是健康、高效养殖的有利措施;桑沟湾在现有养殖模式下,目前已基本达到了它的养殖容量,养殖品种分布不变,减少养殖密度至目前的0.9倍会略微提高产量,降低成本;减少湾口海带养殖密度,会大幅度提高贝藻兼养区的营养盐总量和养殖生物产量,从海带与贝类经济价值对比会有更高的效益。人为提高水动力混合或许是解决湾内营养盐缺乏的途径。 展开更多
关键词 养殖容量 水动力影响 精细过程观测 双阻力边界层 物理-生物耦合的养殖生态模型 桑沟湾
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GIS-based Analysis for Hotspot Identification of Tradeoff Between Ecosystem Services: A Case Study in Yanhe Basin, China 被引量:13
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作者 ZHENG Zhenmin FU Bojie FENG Xiaoming 《Chinese Geographical Science》 SCIE CSCD 2016年第4期466-477,共12页
Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hot... Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifi- cally focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots, Based on previous studies of ecosys- tem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further ana- lyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production (NPP) and water yield (WY) in 2000 and 2008 were estimated by using biophysical models, Secondly, correla- tion analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index (TINpp/wy) was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINpp/wy is 24.4 g/(mm·m2) for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the mid- dle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek poten- tial influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential irtfluencing factor for formulatiort of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem. 展开更多
关键词 correlation analysis net primary productivity water yield tradeoff index inlluencing tactor
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Bio-Economic Strategy to Combat Non-Point Pollution in China 被引量:6
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作者 B. DAVIDSON R.E.WHITE 《Pedosphere》 SCIE CAS CSCD 2005年第2期156-163,共8页
While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic... While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment. 展开更多
关键词 crop production integrated biophysical-economic model non-point pollution policy instrument sustainable strategy
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基于时变纹元的真实感草地枯萎模拟 被引量:1
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作者 焦少慧 杨刚 +1 位作者 HENG Pheng-Ann 吴恩华 《软件学报》 EI CSCD 北大核心 2010年第9期2224-2236,共13页
对表示复杂自然物体的纹元(texel)方法进行扩展,提出时变纹元的概念,以模拟草叶、毛发等自然物体随时间而变化的真实感效果.时变纹元内存储着自然物体随时间变化的纹元数据,从而可用于构建时变三维数据场,实现物体时变效果的模拟.采用... 对表示复杂自然物体的纹元(texel)方法进行扩展,提出时变纹元的概念,以模拟草叶、毛发等自然物体随时间而变化的真实感效果.时变纹元内存储着自然物体随时间变化的纹元数据,从而可用于构建时变三维数据场,实现物体时变效果的模拟.采用一种纹元变形算法来生成时变纹元,该算法首先将基本纹元结构转化为点模型,然后对点模型进行动态模拟来生成时变数据,再将时变的点模型数据进行转化而得到时变纹元结构.运用时变纹元方法实现了草地随时间逐渐枯萎效果的真实感模拟.为了能够模拟草地枯萎变化过程中真实的形态、材质变化,基于物理学以及生物学原理构建了物理-生物模型来指导草地点模型的动态变化模拟,同时生成草地时变纹元.将所生成的草地时变纹元重复性地映射在地形网格上,就可以实现大规模草地场景枯萎效果的模拟.另外,在时变纹元映射过程中还应用了混合叠加算法来增加草地多样性,并运用LOD算法来提高绘制效率.实验结果表明,采用时变纹元方法可以成功实现草地时变效果的真实感模拟. 展开更多
关键词 时变纹元 纹元变形 模型 物理-生物模型 时变度
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A New Model on Origin and Evolution of Biology 被引量:1
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作者 王奕蛟 冯綮一 柴立和 《Agricultural Science & Technology》 CAS 2009年第4期4-7,共4页
Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on th... Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research. 展开更多
关键词 Biological origin and evolution COMPLEXITY Generalized entropy
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台风对上层海洋初级生产力和营养盐输运的影响 被引量:3
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作者 潘珊珊 史洁 +2 位作者 高会旺 徐昭 颜秀花 《中国海洋大学学报(自然科学版)》 CAS CSCD 北大核心 2016年第6期120-133,共14页
利用垂直一维物理-生物耦合模型模拟了台风"派比安"和超强台风"珍珠"对南海北部水温、营养盐和叶绿素垂直分布的影响,并估算了2次台风对初级生产力和营养盐垂直输送的贡献。结果表明,"派比安"引发50m以... 利用垂直一维物理-生物耦合模型模拟了台风"派比安"和超强台风"珍珠"对南海北部水温、营养盐和叶绿素垂直分布的影响,并估算了2次台风对初级生产力和营养盐垂直输送的贡献。结果表明,"派比安"引发50m以浅海水温度降低,表层降温2.0℃,50~130m海水温度升高,混合层加深30m,海表叶绿素浓度增加0.18mg·m^(-3),营养盐垂向输运对初级生产力的贡献为2.3×103 mg C·m^(-2),约占全年的3%。"珍珠"引发55m以浅海水温度降低,表层降温超过5.0℃,55~150m海水温度升高,混合层加深85m,海表叶绿素浓度增加0.9mg·m^(-3),带来的营养盐垂向输运量约为全年的30%,对初级生产力的贡献为12.8×103 mg C·m^(-2),约占全年的18%。可见,台风过程,特别是强台风过程对上层海洋的初级生产和生物地球化学过程具有显著影响。台风的强度和移动速度等自身特征是决定海洋环境要素对台风响应程度的核心要素,同时台风过境前的水体层化状态和营养盐水平也是不可忽视的因素。 展开更多
关键词 南海北部 台风 浮游植物水华 初级生产力 物理-生物耦合模型
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未来黄、东海营养盐浓度变化情景预测 被引量:2
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作者 赵一丁 杨波 +1 位作者 魏皓 赵亮 《海洋与湖沼》 CAS CSCD 北大核心 2015年第5期983-994,共12页
本文基于FGOALS(Flexible Global Ocean-Atmosphere-Land System model)对未来气候情景的预测结果,结合千年生态评估的未来两个情景下的河流营养盐载荷特征,利用黄、东海水动力模型和生态模型并采用降尺度的方法对未来黄、东海营养盐的... 本文基于FGOALS(Flexible Global Ocean-Atmosphere-Land System model)对未来气候情景的预测结果,结合千年生态评估的未来两个情景下的河流营养盐载荷特征,利用黄、东海水动力模型和生态模型并采用降尺度的方法对未来黄、东海营养盐的分布特征进行情景预测。结果表明,两个情景下未来河口邻近海区营养盐浓度将显著增加,富营养化加剧;GO(Global Orchestration)情景下,河流无机氮载荷增幅较大,夏季黄海中部无机氮浓度明显升高;AM(Adapting mosaic)情景下,由于河流无机磷载荷增幅较大,海区氮磷比有所下降,夏季黄海中部表层无机氮浓度降低,而在底层升高。通过敏感性实验并结合收支分析对各海区水动力条件未来变化、河流载荷变化的相对贡献进行了评估:相对于水温和水动力环境改变,河流营养盐排放量的增长是未来营养盐浓度增加的主要原因。营养盐收支分析表明,未来对流和混合输运的变化有助于黄海营养盐浓度的增加,夏季生物量升高造成更多碎屑沉降并在底层矿化使得层化季节冷水团底部营养盐浓度增长;长江口邻近海区营养盐浓度增长主要受冲淡水羽流的影响;净初级生产增加加剧了营养盐的消耗。 展开更多
关键词 营养盐浓度 未来情景预测 物理-生物耦合模型 降尺度 黄、东海
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Biological Autonomy 被引量:1
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作者 Attila Grandpierre Menas Kafatos 《Journal of Philosophy Study》 2012年第9期631-649,共19页
We argue that genuine biological autonomy, or described at human level as free will, requires taking into account quantum vacuum processes in the context of biological teleology. One faces at least three basic problem... We argue that genuine biological autonomy, or described at human level as free will, requires taking into account quantum vacuum processes in the context of biological teleology. One faces at least three basic problems of genuine biological autonomy: (1) if biological autonomy is not physical, where does it come from? (2) Is there a room for biological causes? And (3) how to obtain a workable model of biological teleology? It is shown here that the solution of all these three problems is related to the quantum vacuum. We present a short review of how this basic aspect of the fundamentals of quantum theory, although it had not been addressed for nearly 100 years, actually it was suggested by Bohr, Heisenberg, and others. Realizing that the quantum mechanical measurement problem associated with the "collapse" of the wave function is related, in the Copenhagen Interpretation of quantum mechanics, to a process between self-consciousness and the external physical environment, we are extending the issue for an explanation of the different processes occurring between living organisms and their internal environment. Definitions of genuine biological autonomy, biological aim, and biological spontaneity are presented. We propose to improve the popular two-stage model of decisions with a biological model suitable to obtain a deeper look at the nature of the mind-body problem. In the newly emerging picture biological autonomy emerges as a new, fundamental and inevitable element of the scientific worldview. 展开更多
关键词 SPONTANEITY TELEOLOGY biological aim vacuum processes quantum indeterminacy CONSCIOUSNESS
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Comparison Between Radial Basis Function Neural Network and Regression Model for Estimation of Rice Biophysical Parameters Using Remote Sensing 被引量:10
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作者 YANG Xiao-Hua WANG Fu-Min +4 位作者 HUANG Jing-Feng WANG Jian-Wen WANG Ren-Chao SHEN Zhang-Quan WANG Xiu-Zhen 《Pedosphere》 SCIE CAS CSCD 2009年第2期176-188,共13页
The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and ra... The radial basis function (RBF) emerged as a variant of artificial neural network. Generalized regression neural network (GRNN) is one type of RBF, and its principal advantages are that it can quickly learn and rapidly converge to the optimal regression surface with large number of data sets. Hyperspectral reflectance (350 to 2500 nm) data were recorded at two different rice sites in two experiment fields with two cultivars, three nitrogen treatments and one plant density (45 plants m^-2). Stepwise multivariable regression model (SMR) and RBF were used to compare their predictability for the leaf area index (LAI) and green leaf chlorophyll density (GLCD) of rice based on reflectance (R) and its three different transformations, the first derivative reflectance (D1), the second derivative reflectance (D2) and the log-transformed reflectance (LOG). GRNN based on D1 was the best model for the prediction of rice LAI and CLCD. The relationships between different transformations of reflectance and rice parameters could be further improved when RBF was employed. Owing to its strong capacity for nonlinear mapping and good robustness, GRNN could maximize the sensitivity to chlorophyll content using D1. It is concluded that RBF may provide a useful exploratory and predictive tool for the estimation of rice biophysical parameters. 展开更多
关键词 biophysical parameters radial basis function regression model remote sensing RICE
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Physical and chemical processes promoting dominance of the toxic cyanobacterium Cylindrospermopsis raciborskii 被引量:4
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作者 Michele A. BURFORD Timothy W. DAVIS 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期883-891,共9页
The freshwater cyanobacterium, Cylindrospermopsis raciborskii (Woloszyflska) Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxi... The freshwater cyanobacterium, Cylindrospermopsis raciborskii (Woloszyflska) Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxins (cylindrospermopsins, saxitoxins), making blooms of this species a serious health concern for humans. In the last 10 15 years, there has been a considerable body of research conducted on the ecology, physiology and toxin production of this species and this paper reviews these studies with a focus on the cylindrospermopsin (CYN)-producing strains. C. raciborskii has low light requirements, close to neutral buoyancy, and a wide temperature tolerance, giving it the capacity to grow in many lentic waterbodies. It also has a flexible strategy with respect to nitrogen (N) utilisation; being able to switch between utilising fixed and atmospheric N as sources of N fluctuate. Additionally this species has a high phosphate (DIP) affinity and storage capacity. Like many cyanobacteria, it also has the capacity to use dissolved organic phosphorus (DOP). Changes in nutrient concentrations, light levels and temperature have also been found to affect production of the toxin CYN by this species. However, optimal toxin production does not necessarily occur when growth rates are optimal. Additionally, different strains of C. raciborskii vary in their cell quota of CYN, making it difficult to predict toxin concentrations, based on C. raciborskii cell densities. In summary, the ecological flexibility of this organism means that controlling blooms of C. raciborskii is a difficult undertaking. However, improved understanding of factors promoting the species and toxin production by genetically capable strains will lead to improved predictive models of blooms. 展开更多
关键词 CYANOBACTERIA FRESHWATER algal toxins NUTRIENTS light temperature
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Modeling the Effects of Nutrient Dynamics and Surface Circulation on the Productivity of Hooghly Estuary
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作者 Saswati Dcb Arun Chakraborty 《Journal of Shipping and Ocean Engineering》 2012年第5期255-262,共8页
River estuarine environment plays a key role in the cycling of biological and chemical parameters and a significant region for the transaction of freshwater and seawater. In the present study, a first attempt has been... River estuarine environment plays a key role in the cycling of biological and chemical parameters and a significant region for the transaction of freshwater and seawater. In the present study, a first attempt has been made towards the development of a coupled three-dimensional hydrodynamic circulation model with four compartment (nitrate, phytoplankton, zooplankton and detritus) biogeochemical model in the Hooghly estuary (21 °36′-22° 16′1 and 87°42'-88°15′E) to simulate the varying effect of plankton biomass with the heavy input of anthropogenic litter from industrial effluents of Haldia port which is effecting the chemical and biological processes that control the plankton dynamics in the estuary. In-situ observational data for physico-chemical and biological parameters are collected from Calcutta University during 2010 are assimilated using multiscale OA (objective analysis) for different seasons and incorporated in ROMS (Regional Ocean Modeling System) to develop a high resolution (0.5 km x 0.5 kin) biogeochemical model. Recent analysis on physico-chemical parameters of the estuary is done as it is one of the largest estuaries in India and is the habitat for vast biodiversity. Influence of high nitrate (above 34 μg/L) and phosphate (5.22 μg/L) is predominant whereas DO (dissolved oxygen) is low (4.07 mg/L) in the Haldi River mouth which is sliding the productivity (less than 1 mg/L) and also affects water quality. 展开更多
关键词 Biogeochemical model Hooghly estuary OA PRODUCTIVITY ROMS.
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Dynamics of different compound bursting in two phantom bursting mechanism models 被引量:3
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作者 YANG ZhuoQin HAO LiJie 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第5期885-892,共8页
The generic phantom bursting model proposed by Bertram et al.can evoke complex bursting oscillations in collaboration with two generic slow variables with different time scales.Two models with the phantom bursting mec... The generic phantom bursting model proposed by Bertram et al.can evoke complex bursting oscillations in collaboration with two generic slow variables with different time scales.Two models with the phantom bursting mechanism are suggested,when these two generic slow variables are provided with some specific biological significances by combining slowly varying intracellular Ca2+concentration of the Chay-Keizer electrical bursting model with two different glycolytic oscillations,respectively.Also,complex dynamic behaviors of different compound bursting occurring in these two models are comprehensively surveyed by two fast/slow analyses for a moderately and a slower slow variable,respectively. 展开更多
关键词 phantom bursting mechanism compound bursting different time scales fast/slow dynamics analysis
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A generalized model of island biogeography 被引量:2
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作者 CHEN XiaoYong JIAO Jing TONG Xin 《Science China(Life Sciences)》 SCIE CAS 2011年第11期1055-1061,共7页
MacArthur and Wilson's equilibrium theory is one of the most influential theories in ecology.Although evolution on islands is to be important to island biodiversity,speciation has not been well integrated into isl... MacArthur and Wilson's equilibrium theory is one of the most influential theories in ecology.Although evolution on islands is to be important to island biodiversity,speciation has not been well integrated into island biogeography models.By incorporating speciation and factors influencing it into the MacArthur-Wilson model,we propose a generalized model unifying ecological and evolutionary processes and island features.Intra-island speciation may play an important role in both island species richness and endemism,and the contribution of speciation to local species diversity may eventually be greater than that of immigration under certain conditions.Those conditions are related to the per species speciation rate,per species extinction rate,and island features,and they are independent of immigration rate.The model predicts that large islands will have a high,though not the highest,proportional endemism when other parameters are fixed.Based on the generalized model,changes in species richness and endemism on an oceanic island over time were predicted to be similar to empirical observations.Our model provides an ideal starting point for re-evaluating the role of speciation and re-analyzing available data on island species diversity,especially those biased by the MacArthur-Wilson model. 展开更多
关键词 island biogeography SPECIATION IMMIGRATION EXTINCTION area ISOLATION species richness island development
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