Abstract
Semi-convergence of parameterized Uzawa waveform relaxation
method for a class of differential–algebraic equations
Wendi Bao1, Yongzhong Song2
1
China University of Petroleum, China
2
Nanjing Normal University, China
Abstract: In this paper, we propose an efficient parameterized Uzawa waveform
relaxation
method
for
solving
a
class
of
initial
value
problems
of
differential–algebraic equations (DAEs). The semi-convergence of this method is
studied. Furthermore, the optimal iteration parameters and the corresponding optimal
factor for the parameterized Uzawa waveform relaxation method are determined. Two
numerical examples are given to illustrate the theoretical results.
Dynamics of mosquito population with different strategies of
releasing sterile mosquitoes
Liming Cai
Xinyang Normal University, China
Abstract:To prevent the transmissions of malaria, dengue fever, or other
mosquito-borne diseases, one of the effective weapons is using the sterile insect
technique to release sterile mosquitoes to reduce or eradicate the wild mosquito
population. To study the impact of the sterile insect technique on the diseases
transmissions, we formulate mathematical models for the interactive dynamics of the
wild and sterile mosquitoes, incorporating different strategies in releasing sterile
mosquitoes. We investigate the model dynamics and compare the impact of the
different release strategies. Numerical examples are also given to demonstrate rich
dynamical features of the models.
Dynamical Modeling of the West Nile Virus (WNV) transmission
with weather conditions
Longbin Chen
York University, Canada
Abstract: Weather (temperature and precipitation) can affect the abundance and the
behavior of vector mosquitoes for West Nile virus. In this study, we incorporate
weather conditions to a compartmental model for the transmission of West Nile
virus in birds and mosquitoes. By using the mosquito abundance from a statistical
model and surveillance data from the Peel Region, Ontario, we explore and simulate
numerically how the weather conditions effect the transmission. Some simulation
results under different weather patterns will be presented to illustrate the complex
dynamics of the transmission.This is a work supervised by Professor Steven Wang
and Huaiping Zhu.
The dynamics of temperature and light on the growth of
phytoplankton
Ming Chen
Northeast Normal University, China
Abstract: Motivated by some lab and field observations of the hump shaped effects
of water temperature and light on the growth of phytoplankton, a bottom-up nutrient
phytoplankton model, which incorporates the combined effects of the environmental
factors such as temperature and light, is proposed and analyzed to explore the
dynamics of phytoplankton bloom. The comprehensive population growth model
reasonably captures such observed dynamics qualitatively. An ecological reproductive
index R0 is defined to characterize the growth of the phytoplankton and to make a
comprehensive analysis of the role of abiotic factors on the growth and reproductive
characteristics of phytoplankton in general. The model provides a sound framework to
study the mechanisms of phytoplankton dynamics in shallow lake and may even be
employed to study the controlled phytoplankton bloom.
Overcompensation and competitive effects of Microcystis
aeruginosa and Scenedesmus obliquus after low temperature
and light stresses
Zifa Deng
Nantong University, China
Abstract: Changes of temperature and light significantly influence the growth and
activity of phytoplankton. To explore the effects of these two variables on the
cyanobacterial blooms, we analyzed the growth of Microcystis aeruginosa and
Scenedesmus obliquus, as well as the competition between the two species, under
conditions of low temperature and low light, and under conditions of release from
these two stress factors. The results showed that low temperature and low light
significantly inhibited the growth of microalgae. Low temperature led to a stronger
inhibitory effect on M. aeruginosa than low light did; however, the growth inhibition
of S. obliquus was more sensitive to low light than to low temperature. After release
from low temperature or limiting light, all of the experimental taxa exhibited the
overcompensation growth within a limited time and this response varied by species.
Two M. aeruginosa strains showed a greater response to increased temperature than
increased light. However, overcompensation of S. obliquus was greater in response to
increased light than increased temperature. When the species were grown together,
results showed that under all culture conditions, the toxic Microcystis strains (912)
had a competitive advantage over S. obliquus. Although there was no significant
difference between the competitive ability of the nontoxic Microcystis strain (469)
and S. obliquus under the normal, the former (469) showed a competitive disvantage
to S. obliquus under conditions of release from low light and low temperature.
Chlorophyll-a content of all experimental algae overcompensated when released from
light limitation. In the temperature experiments, the increase of chlorophyll-a content
and algal density were asynchronism for all species, and cryogenic pre-treatment had
a negative after-effect on microalgae chlorophyll-a content under release from low
temperature. The response of dehydrogenase activity of algae when released from low
temperature or low light stress varied with algae species, and the compensating
increase of dehydrogenase activity of toxic strains (912) was significantly higher than
that of the other two taxa. The results suggested that higher the compensatory growth
of toxic Microcystis as well as its competitive advantage over S. obliquus while
released from low temperature and light stresses, might be the important mechanisms
that result in blue-green algae bloom.
Probabilistic Climate Projection of Extreme Events
---A case study over Northern America and Tai Lake
Ziwang Deng
York University, Canada
Abstract: Extreme events in recent years have been extremely damaging and have
been a catalyst for more urgent analysis of the relationship between extreme weather
and climate change. The multi-model ensembles have been used to quantify
uncertainty in climate projections. This study uses data from WCRP CMIP3
Multi-Model Dataset, North American Regional Climate Change Assessment
Program (NARCCAP), North American Regional Reanalysis (NARR) and Climate
Forecast System Reanalysis (CFSR) for climate projection of extreme climate events
over North America. An analysis is also performed to the Taihu area. To measure the
extreme events, 11 precipitation indices and 7 temperature indices were calculated for
current and future periods. Based on the relationship between indices from paired
GCM-RCM runs, a set of downscaling models were developed and applied to
downscale these indices from all GCM ensembles. Empirical method is then used to
quantify the uncertainty of the projection of these indices by estimate the empirical
probabilistic distribution function at each model grids for each climate extreme index.
Results show that as the global warming, both mean and extreme temperatures over
North America increase significantly in the future, causes the increasing of hot-days,
decreasing of cold-nights and increasing of the risk of heat wave over many areas.
The PDF of the extreme precipitation is becoming flatter suggesting the number of
droughts and floods are also increasing over some areas. Analysis of precipitation and
temperature data over Tai Lake shows the temperatures (mean and extreme) will
continue increase in the future and minimum temperature will increase faster than
maximum temperature. Thus, the extreme hot temperature events (hot days and warm
nights) will significantly increase. The change in total precipitation is relatively small.
Further analyses with higher resolution model outputs are desired for Tai Lake region.
This is a joint work with Neal Madras, Xin Qiu and Huaiping Zhu.
Zooplankton and diatom communities in Ontario lakes:
response to stressors
Jörg Grigull
York University, Canada
Abstract:
1) Freshwater zooplankton diversity on the Canadian Shield;
2) Diatom assemblages: recovery from lake acidity and metal pollution;
3) Perspective: bioinformatic methods in stress-induced gene plasticity.
As waterborne insects, zooplankton plays a key role in trophic networks in both
marine and freshwater ecosystems. Stoichiometric ecology aims to explain the
prevailing functional traits in a species assemblage by biogeochemical features of
their habitat. Findings on the functional diversity in freshwater zooplankton in ~300
lakes in Southeast Ontario under various elemental and morphometric
gradients, as
part of an ongoing project with the Canada Water Network (CWN), are presented.
Diatom assemblages from sediment cores in three Ontario lakes near a mining site are
matched with present conditions in reference lakes: We discuss the potential of
statistical methods in their application to paleolimnological data to provide guidance
in lake restoration. Related research on gene regulation and gene plasticity under
stress conditions is presented:
a) a genome-wide gene expression studies of mRNA
stability in Saccharomyces cerevisiae;
b) an example on the mediation of somatic
mutations by transient ssDNA structures in immunology and a computational
paradigm of predicting microbial DNA plasticity.
Refuge Effect of Submerged Macrophytes in Aquatic Ecosystems:
Modeling Approach
Lina Hao
Northeast Normal University, China
Abstract: A number of studies have documented that macrophytes provide a refuge
for herbivorous zooplankton against predation by fish. Therefore, the refuge effect of
macrophytes is considered in the modeling the functional response of fish and then a
phytoplankton-zooplankton-macrophyte-fish model is proposed. Qualitative analysis
and numerical simulations illustrate that our model possesses complex dynamical
behaviors, such as bistable phenomenon and chaotic phenomenon. Our numerical
analysis also demonstrates that the refuge constant, the density of the macrophytes
and the intraspecific competition between the macrophyte and the phytoplankton are
important impact factors of the refuge effect. Therefore, planting some macrophytes,
which have refuge effect for zooplankton, might be an effective mean to control the
algae blooms in the aquatic ecosystem.
Dengue early warning: Forecast of dengue incidence based on
temperature and rainfall
Yien Ling Hii1, Huaiping Zhu2, Nawi Ng1, Lee Ching Ng3, Joacim Rocklöv1
1. Umeå Centre for Global Health Research, Epidemiology and Global Health,
Department of Public Health and Clinical Medicine, Umeå University, Sweden.
2. Laboratory of Mathematical Parallel Systems, Department of Mathematics &
Statistics, York University, Toronto, Ontario, Canada
3. Environmental Health Institute, National Environment Agency, Singapore
Abstract：Dengue has been spreading rapidly in recent decade placing at least one third
of the world’s population at risk of the disease. About 50-100 millions cases are
reported annually from over 100 countries in tropical and sub-tropical regions. Dengue
is a viral infectious disease transmitted by mosquitoes. Normally, an infected person
recovers within a few weeks; however, fatal complications can develop in a small
percentage of patients. Without drug for treatment or vaccine for prevention, vector
control remains the most effective strategy to control dengue outbreaks. Thus, a simple
and precise early warning would provide an avenue for timely mitigation and enhances
the effectiveness of control measures.
Dengue is a climate-sensitive disease. The impacts of climate on dengue are translated
through the influence of climate on the biological aspects and infective capacity of
Aedes mosquitoes as well as on the duration of extrinsic incubation period of dengue
viruses. We explored the feasibility of developing a dengue early warning system in
Singapore using climate as the main predictor. We analyzed the links between dengue
cases and climate, evaluated the optimal lead-time that would allow sufficient time for
mitigation, and developed forecasting models using multivariate Poisson regression.
Autoregression, trend, and seasonality were considered in the models to account for
non-climatic risk factors. The relative risk of dengue incidence increases subsequent to
favorable weather conditions and an early warning of dengue outbreak at least 3 months
ahead provides sufficient time for response. Our findings show that it is feasible to
predict dengue cases up to 16 weeks based on climate, while consideration of
non-climatic factors enhances precision of forecast. We also discussed the strengths of
predictive models and factors, and described influences and limitations posed by other
factors.
A climate-based forecasting model could be a simple, precise, and low cost tool to
enhance decision-making on the timing and scale of vector control exercises as well
as utilization of scarce resources. The use of climate to forewarn local authority for
the risk of dengue outbreak could also be an optimal solution for countries with
constraint of resources since climate data is publicly available in most countries.
Nevertheless, an outbreak of dengue is a consequence of virus-vector-host interaction,
which is generally complicated by the influence of multiple external complex factors
on each element in the chain of infection. Simultaneously, the dynamic of disease
transmission is evolving over time in accordance with the evolution or emergence of
new strains of dengue viruses, the capacity and effectiveness of control measures, as
well as the adaptation of vectors in response to harsh environment including intensive
source reduction exercises. Therefore, a dengue early warning based on historical
climate data and distribution pattern inevitably faces challenges on the sustainability
of forecast precision in the long run. Further studies to address the challenges are
encouraged to enhance functionality of a dengue early warning system.
Stochastic models for algal bloom with and without delay
Xuehui Ji, Sanling Yuan, Huaiping Zhu
College of Science, University of Shanghai for Science and Technology,
Shanghai 200093, China
Abstract：In this paper, two stochastic models for algal bloom with and without
distributed delay are investigated. We introduce white noise term into the growth
equation of algae population to describe the effects of environmental random
fluctuations, and the delay into the nutrient equation to account for the time needed in
the conversion of detritus into nutrient. The existence and uniqueness of the global
positive solutions for both the two models are proved. By constructing Lyapunov
function(al)s, sufficient conditions for the stochastic stability of their washout
equilibrium are both obtained. Furthermore, for the model without delay, we show
that under certain conditions, both the nutrient and the population fluctuate within
some certain range of values around the positive equilibrium of its corresponding
determinate model; for the delayed model, our theoretical results show that it has the
same long term behavior as the one without delay, which means that the delay does
not affect the long term behavior of the system, though the numerical simulations
reveal that it may reduce the level of algae population in a short time.
Long-Term Behavior of May-Leonard Model with Equal
Periodic Intrinsic Growth Rate ----From Numerical Experiment
to Rigorous Proof
Jifa Jiang
Shanghai Normal University, China
Abstract：Both autonomous symmetric and asymmetric May-Leonard models have
trichotomy dynamics: either almost all trajectories approach a heterclinic cycle, or
system has a family of closed orbits and almost all trajectories are asymptotic to a
closed orbit, or all positive trajectories converge to the positive equilibrium.
Influenced by seasonal change, the intrinsic growth rate in species population models
should depend on time. The May-Leonard model with equal periodic intrinsic growth
rate is investigated. We first choose constant intrinsic growth rate and competitive
coefficients such that the above three cases occur respectively. Then we perturb the
intrinsic growth rate by a periodic function and make numerical simulation.
Comparing the solution curves between unperturbed and perturbed systems, we find
the solution curves for perturbed systems oscillate around the solution curves of
unperturbed systems in a direction transversal to the trajectories of unperturbed
systems. Then we conjecture that the relation between solutions of perturbed system
and unperturbed system. Finally, we prove this conjecture rigorously. By this relation,
we deduce that the May-Leonard model with equal periodic intrinsic growth rate
possesses trichotomy dynamics: either almost all solutions approach the boundary of
carrying simplex; or system has a family of uncountable quasiperiodic solutions and a
countable subharmonic solutions, and almost all solutions converges one of them; or
all positive solutions are asymptotic to a unique positive periodic solution.
The water environmental information sharing platform of Taihu
Lake Basin
Gang Li
Jiangsu Provincial ecological environmental monitoring center, China
Abstract: The key technologies of the water environmental information sharing
platform of Taihu Lake Basin were described on the data exchange, three-dimensional
display, online analytical processing and data mining of environmental information. It
explored the design concept and the direction of development of the integration of
environmental information, the multi-dimensional display and comprehensive
analysis of environmental information for solving the bottleneck of environmental
information sharing and promoting the modernization of environmental management.
Modelling and Analysis of the Effects of Dissolved Oxygen on
the Growth of Phytoplankton and Zooplankton
Juan Li
Nanjing Normal University, China
Abstract: In order to investigate the effects of dissolved oxygen concentration on the
growth of phytoplankton and zooplankton and better understand the mechanism of
outbreaks of algal bloom, a dynamical model including phytoplankton, zooplankton
and dissolved oxygen is proposed and analyzed. By both dynamical analysis and
numerical simulations, our findings show that, (1) When the corresponding system is
in a stable state, the density of zooplankton increases and the density of phytoplankton
decreases as dissolved oxygen concentration increases gradually; (2) Zooplankton
becomes extinct and the density of the phytoplankton reaches the environmental
capacity when the dissolved oxygen drops below a threshold level; (3) The existence
of periodic oscillatory solutions suggests that the algal bloom is likely to occur on
different scales.
The diffusive SIS model in a low-risk or high-risk domain:
Spreading or vanishing of the disease
Zhigui Lin
Yangzhou University, China
Abstract: A SIS reaction-diffusion model is investigated to understand the impact of
spatial heterogeneity of environment on the persistence and extinction of a disease.
The free boundary is introduced to describe the spreading front of the disease. The
behavior of positive solutions to a reaction-diffusion system in a radially symmetric
domain are discussed. The basic reproduction number $R_0^D$ is defined for the
reaction diffusion system with Dirichlet boundary condition, and then the basic
reproduction number $R_0^F(t)$ is introduced for this spatial SIS model with the free
boundary, sufficient conditions for the disease to vanish or spread are given. Our
result shows that the disease will spread to the whole area if there exists a $t_0\geq 0$
such that $R_{0}^F(t_0)\geq 1$, that is, if the spreading domain is high-risk at some
time, the disease cannot control, while if $R_{0}^F(0)<1$, whether the disease is
vanishing or spreading depends on the initial value of the infective.
Asymptotic behaviors of a periodic system of plankton
allelopathy subject to impulsive perturbations
Zhijun Liu
Hubei University for Nationalities，China
Abstract: The main purpose of this paper is to study the asymptotic behaviors of a
periodic differential system of the growth of two species of plankton having
competing and allelopathic effects on each other in which the system is controlled by
menas of impulsive harvesting and stocking controls. A good understanding of
coexistence, partial extinction and gllobal attraction of the impulsive system is gained.
It turns out that the impulsive controls play a crucial role in shaping the above
dynamics of the system. Numerical simulations are presented to substantiate the
analytical results.
Impacts of climate change, large-scale climate drivers, and
weather on ice formation and breakup
Jonathan L.W. Ruppert*, Sapna Sharma, and John J. Magnuson
York University, China
Abstract: Contemporary ice records across the Northern Hemisphere tend to reveal
later ice formation, earlier ice break-up, and a shorter annual duration of ice cover
over the past 150 years. Here we use the longest human records of ice formation
(1443-2004; Lake Suwa, Japan) and break-up (1693-2013; River Tornionjoki,
Finland) to: (1) determine long-term trends in ice dynamics, (2) investigate whether
variance in ice formation and break-up are changing and (3) identify what factors may
be driving changes in ice dynamics. Using a Bayesian approach we identify a major
shift in ice formation at Lake Suwa (32.1 days later) and ice break-up at the River
Tornionjoki (8.3 days earlier) over the 550- and 320-year records, respectively. The
shifts in ice dynamics in these systems coincide with increasing human populations,
the end of the little ice age and the onset of the industrial revolution. We also find that
Lake Suwa experiences a higher frequency of no ice formation in the more
contemporary period and appears to be approaching a phenological threshold for ice
dynamics. In contrast, variance in ice break-up date at the River Tornionjoki has been
decreasing through the more recent time period. This coincides with a significant shift
in drivers of ice break-up from cycle lengths of 2-6 and 18-32 years in the earlier
period to cycle lengths of 7-15 years in the more contemporary period. Finally, using
boosted regression tree analysis, we identify that global climate drivers such as
atmospheric CO2 concentration, solar sunspot number, and solar irradiance, in
addition to local and regional temperatures, appear to play a large role in ice dynamics
in both systems.
The impacts of climate multiple stressors on aquatic ecosystems:
A landscape perspective
Sapna Sharma
York University, Canada
Abstract: Global air temperatures have increased by approximately 1°C over the
past century and are projected to rise between 1.4 and 5.8°C over the next
century. The objective of this presentation is to examine three potential impacts of
multiple environmental stressors on aquatic ecosystems: i) the effects of climate
change on the spread of invasive species, ii) the effects of climate change on lake ice
dynamics, and iii) effects of land use change on degradation of water quality.
First,
I will present a case-study focusing on lakes across Canada illustrating that
smallmouth bass, a non-native warmwater fish species, could reach the Arctic by 2100
under climate change. The spread of smallmouth bass could lead to the loss of
20,000 lake trout populations across the country, in addition to the loss of minnow and
salmon populations. Second, I will assess how climate has already changed over the
past 150-550 years by examining lake ice dynamics. Lakes across the Northern
Hemisphere are melting four times faster in the past 50 years (relative to the past 150
years). In addition to climate change, weather and large-scale climatic drivers
influence the timing of lake ice breakup. Third, I will identify the relative
importance of large-scale climate drivers, weather, hydrology, and internal lake
characteristics on degradation of water quality for lakes in the Canadian Great
Plains. Increases in water temperature resulting from climate change are projected to
have a greater impact on future water quality than proposed industry-driven changes
in hydrologic inflow regimes, requiring specific management recommendations for
preserving water quality in prairie lake ecosystems.
Global dynamics of a nutrient-plankton system in the water
ecosystem
Aijun Fan, Peng Han, Kaifa Wang*
Third Military Medical University , China
Abstract: To quantitatively study the relationship between nutritional enrichment and
the oscillation of water quality, a new nutrient-plankton dynamics model is proposed
in the light of a water ecosystem, such as the Three Gorges Reservoir Area. The
derived results show that the plankton-free equilibrium is globally asymptotically
stable if the concentration of the input nutrient is sufficient small. When nutrient
recycling is absent, the zooplankton-free equilibrium is globally asymptotically stable
for the middle concentration of the input nutrient, whereas the coexistent equilibrium
is globally asymptotically stable for sufficient large concentration of the input
nutrient. Furthermore, numerical simulation results confirm that the comprehensive
effect of eutrophication by environmental pollution, nutrient recycling and excessive
fishing intensity can induce the oscillation of water quality and the collapse of the
water ecosystem.
The long time behavior of a stochastic SIRS epidemic model wit
h saturated incidence
Feng Wang
Southeast University, China
Abstract:In this talk, we discuss a stochastic SIRS epidemic model with saturated inc
idence. The p-moment'supper bound of solution are estimated. In addition, the long ti
me
behavior of the stochastic systems is studied. Mainly, we show how the solution goes
around the infection-free equilibrium and the endemic equilibrium of deterministic sy
stem
under different conditions.
Water level fluctuations for manipulating macrophyte germination
and growth in shallow lakes
Guoxiang Wang
Jiangsu Key Laboratory of Environmental Change and Ecological Construction
College of Geographical Science, Nanjing Normal University, Nanjing 210023, China
Abstract: Being a pivotal biological component of organisms in shallow lakes,
macrophytes play a key role in maintaining the structural stability of lake ecosystems,
in promoting the water self-purification capacity and in improving the water quality.
Regressive succession and/or disappearance of macrophytes causes algal blooms and
water quality decline in eutrophic lakes. Based on the investigation over water level
and macrophytes’ dynamics in typical shallow lakes, the effects of water level
fluctuation on the germination, seedling growth and biomass accumulation were
studied in the emergent plants Phragmites communis, Typha angustifolia and in the
submersed plants Potamogeton crispus, Hydrilla verticillata and Vallisneria spiralls.
Resulted showed that long-term drought-induced ground water table falling or low
soil water content could greatly inhibit the germination of P. communis and T.
angustifolia. The germination rates at a low soil water content of 10% were 64% in P.
communis and 32.5% in T. angustifolia, and the germination rates were elevated
along the increase of soil water content. After flooding, the germination rates of both
plants decreased as the water table rising. The germination rate of P. communis was
44% at a flooding depth of 15 cm compared to the rate of 60% in T. angustifolia at a
depth of 100 cm. Water levels showed no obvious impact on the germination of
submersed plants, and significantly affected the seedling growth in a distinctive way
between Phragmites communis and Hydrilla verticillata. After a 2 month cultivation,
the stem height of P. communis in a water level of 1.5-2.0 m was twice that in 3.0 m,
and the height progressively decreased when the water level rising. Similarly in H.
verticillata, the stem height increased gradually as the water level increasing within
0.5-2.0 m, while decreased within 2.0-4.0 m. At the water level of 3.0, 3.5 and 4.0 m,
seedlings of H. verticillata died at day 55, 33 and 21, indicating when beyond the
suitable range the increase of water level drastically inhibit H. verticillata growth. The
simulation of regular rising of water level showed that no apparent difference
appeared between the H. verticillata plants growing under a regular rising water level
from 0.5 m to a final 1.0 m or 2.0 m within 25 days and those growing in a permanent
1.0 m or 2.0 m respectively. However, when the water level raised from 0.5 m to 3.0
m within 25 days, H. verticillata plants grew well and the stem height reached a 296.5
cm at the final stage while those seedlings cultivated at 3.0 m water depth from the
very beginning of experiment died at day 55. The slow rising of water table during
flooding thus stimulated the growth of H. verticillata plants while rapid rising will in
adverse inhibit its growth.
This is a joint work with HAN Ruiming, CAO Xun, LI Zhengguo, WU Xiaodong, LI
Qiang, CAO Yun and
LIU Yu.
水生植物是浅水湖泊的关键生物，对于维护湖泊生态系统结构稳定、提高水体自净能力、
改善水质有重要作用。水生植物退化甚至消失，是藻型富营养化湖泊水华暴发、水质下
降的重要原因。基于典型湖泊水位波动与水生植被动态变化的调查，模拟研究了水位波
动对挺水植物芦苇、香蒲及沉水植物菹草、黑藻、苦草等萌发、幼苗生长及生物量的影
响。结果表明，长期干旱导致的地下水位过低、土壤水分含量低，对芦苇、香蒲繁殖体
的萌发有明显抑制，在土壤水分含量 10%时，芦苇的萌发率为 64%，而菖蒲仅 32.5%，
随着土壤水分含量升高，2 种挺水植物萌发率明显上升；而淹水后，随着淹水深度增加，
挺水植物萌发率明显下降，芦苇淹水 15cm 时，萌发率仅 44%，菖蒲淹水 100cm 时，萌
发率仍然有 60%。不同水位（水深）对于沉水植物菹草和黑藻繁殖体的萌发均无显著影
响，但是，不同水位对菹草和黑藻幼苗生长的影响有显著差异，菹草生长 2 个月时，水
深 1.5-2.0m 组的株高为 3.0m 组的 2 倍，水深 2.0-4.0m 的各组，随着水深增加，菹草株
高呈下降趋势；水深对黑藻幼苗生长的影响类似于菹草，水深 0.5-2.0m 的各组，黑藻的
株高随着水深增加而增加，而水深 2.0-4.0m 的各组，黑藻的株高随着水深增加而降低，
水深 3.0、3.5 和 4.0m 的各组黑藻幼苗分别在 55d、33d 和 21d 死亡，表明水深超过适宜
深度后，
水深增加对黑藻幼苗生长有显著抑制。水位上升模拟试验结果表明，水位从 0.5m
处起，在 25d 内以不同上升速率分别上升至 1.0m 和 2.0m，与开始就生长在 1.0m 和 2.0m
处的相比，水位缓慢上升对黑藻生长无显著影响；在 3.0m 水深处生长的黑藻幼苗 55d
时死亡，但是，水位自 0.5m 处起，在 25d 内逐渐上升至 3.0m，黑藻生长良好，株高达
296.5cm，表明水位缓慢上升对黑藻生长有明显促进作用，但是，水位上涨过快对黑藻
生长会有明显的抑制作用。
Modeling seasonal effect on algae bloom
Wendi Wang
Southwest University, China
Abstract: First, I will present a simple model to simulate the seasonal in°uences on
algae bloom in a lake. Then I will discuss the algae blooming threshold according to
the reproduction number. Some simulations are given to illustrate the influences of
seasonal effects.
Stability analysis and control of Equilibrium point in
plankton population model
Xuedi Wang
Jiangsu University, China
Abstract: In this paper, a plankton population model with a non-integer exponent of
closure term is studied by using the theory of ordinary differential equation and
bifurcation. For all the equilibrium points, we adopt Washout filter feedback
controller to control the stability of the equilibrium points, and then the bifurcations
can be eliminated. Finally, all the results obtained are verified by numerical
simulation.
Solid waste resource and reuse in purifying wastewater
Weiben Yang
Nanjing Normal University, China
Abstract: In order to deal with and utilize agricultural waste, reduce wastewater
treatment costs, coagulants and adsorbents with different functions can be prepared
with plant fiber waste as raw material by chemical modification for rapid removal of
organic pollutants and heavy metals in water. Two-win purpose was reached due to
the waste recycling and water purification.
Noise stability of dynamical systems
Yingfei Yi
Jilin University and Georgia Institute of Technology
Abstract:In this lecture, we consider stochastic differential equations as models in bio
chemical, mechanical, and electrical systems. For a white-noise perturbed system of o
r
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differential equations, new existence and non-existence results of stationary measures
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the conresponding diffusion process will be presented by relaxing the notion of Lyapu
novfunctions. Limiting behaviors of stationary measures will be discussed along with
appli-cations to problems of stochastic stability and bifurcations. In particular, charact
erization of limiting Gibb's measures will be given in responding to the desired ergodi
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isolated particle systems under thermodynamics limits.
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Game Analysis among Central Government, Local Government
and Enterprises in the Background of Energy Saving
Liping Zhang
Nanjing University of Aeronautics and Astronautics, China
Abstract: In this paper, we study the game behavior among central government, local
government, and enterprises in the energy conservation management process. Based
on the revenue, we develop the general punishment and dynamic punishment models
by replicator dynamic method. Furthermore, we analyze these models, discuss the
evolutionary stable strategy and the impact of parameter change on the stable strategy.
Meantime, we verify the result by numerical simulation. Finally, according to the
outcome of the discussion, we give some reasonable proposals to china’s energy
saving.
Dynamical analysis of a harvested plankton model
with delay and diffusion terms
Hongyong Zhao, Xuanxuan Huang
Nanjing University of Aeronautics and Astronautics, China
Abstract: In this talk, we considered a kind of harvested plankton model with delay
and diffusion terms, in which phytoplankton is assumed to undergo exploitation. We
analyze the stability and bifurcation of this model. Some sufficient conditions
ensuring the stability and bifurcation are provided by using stability and bifurcation
theory. The computer simulations are provided to verify the efficiency of the
theoretical results. Specially, the numerical experiments suggest that, the delay and
harvesting have great effects to stability, bifurcation, chaos and pattern formation of
nutrient-phytoplankton-zooplankton-fish model.
Analysis of Harmful Algal Blooms in Tai Lake using a statistical
model with the impact of weather
Xiuqing Zhou
Nanjing Normal University, China